Hepatitis Viruses

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18 Hepatitis Viruses Although hepatitis has been recognized clinically since the time of the earliest recorded medical history, knowledge of its epidemiology was exclusively observational. Perhaps the most insightful information on the illness developed in the 1960s, when the late Saul Krugman and his associates conducted studies on the residents of Willowbrook State Hospital in Staten Island, New York. This work provided for the first time definitive clinical evidence that two different transmissible agents with clearly defined incubation periods were involved. Their insightful work, which later proved to be the target of much public criticism, was based on inoculation of experimental samples of blood containing virus into institutionalized mentally handicapped children, who would have otherwise naturally contracted the infections early in the course of their residence in this long-term custodial setting. My next experience with hepatitis occurred in the early 1970s, when I worked with June Almeida, whose unique skill was with negative staining of viruses, and whose interest at the time was the newly discovered Australian antigen, a morphologic enigma in the blood of patients with the long-incubation form of hepatitis (Almeida et al., 1971). At the time, I was astonished when we regularly discovered this antigen in the blood of healthy Africans while conducting studies on serum samples brought to us from his homeland by the dynamic young Nigerian pathologist A. O. Williams. This finding provided a preliminary insight into the medical importance of chronic subclinical hepatitis B virus infections in Africa, and the potential importance of the viral carrier state so common in Africans and Asians. During the ensuing years, as work with hepatitis B provided interest for legions of investigators, others turned to explore the etiology of the short-incubation hepatitis described as MS-1 by Krugman and his colleagues at Willowbrook. Using the electron-microscopic technique of negative staining, Feinstone and his colleagues (1973) demonstrated the presumptive causative virus in stool samples from patients with acute hepatitis; six years later. Provost and Hilleman

INTRODUCTION 253 ORALLY ACQUIRED SHORT-INCUBATION-PERIOD ACUTE HEPATITIS 254

Hepatitis A Virus (HAV) 254 Hepatitis E Vims (HEV) 255 PARENTALLY ACQUIRED LONG-INCUBATION-PERIOD ACUTE AND CHRONIC HEPATITIS 257

Hepatitis B Virus (HBV) 257 Hepatitis D Virus (HDV) (Delta Agent) 260 Hepatitis C Virus (HCV) 260 CHRONIC HEPATITIS ( C H ) 262 HEPATOCELLULAR CARCINOMA ( H C C ) 264 AUTOIMMUNE HEPATITIS (AH) 270 PAPILLARY ACRODERMATITIS (GIANOTTI-CROSTI SYNDROME; GCS) 271 GLOMERULONEPHRITIS 272 REFERENCES 273

INTRODUCTION It was one of those inadvertent needle pricks self-inflicted while culturing the blood of my newly admitted patient with a fever of unknown origin. I thought little about it at the time, but in retrospect, I was pleased to learn a few days later that the bacterial blood cultures were sterile. The patient was soon discharged afebrile, but without a diagnosis. I can only assume now that it was subclinical hepatitis, for just 30 days later the incident immediately came to mind when my urine exhibited the deep mahogany tint that can only be attributed to bilirubin. I suddenly felt ill, and indeed I soon was, with fever, overwhelming malaise, anorexia, and the obvious jaundice that serves as the basis for the clinical diagnosis of acute hepatitis. At the time, I was aware of the so-called hepatitis A, that is, the short-incubation form, and hepatitis B, the so-called long-incubation form of hepatitis, but little else. As an intern in 1957,1 also possessed some knowledge of postnecrotic cirrhosis, but how and under what circumstances it developed was obscure. There were no diagnostic tests for the hepatitis viruses, and treatment was limited to bed rest and a good diet.

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TABLE 18.1 Features of Hepatitis Viruses: Their Associated Liver Disease Typical transmission mechanism Virus Virus family Nucleic acid type Virion diameter Genotypes Incubation period (days) Viremia Virus in stool Acute mortality Chronic hepatitis Cirrhosis Hepatocellular carcinoma

Perinatal/ parenteral/ sexual

Fecal-oral/ ,waterborne HAV Picornavirus RNA 28 7 15-50 Brief + <1% No No No

HEV Calcivirus RNA 32 3 15^5 More prolonged +


HBV Hepadnavirus DNA 42 5 28-160 Indefinite 0 1% Yes Yes Yes

HDV Deltavirus DNA 43 3 NA Indefinite 0 >20% Yes Yes Yes

HCV Flavivirus RNA 38-50 9 14-160 Indefinite 0 1% Yes Yes Yes

NA = Not applicable ''20-40% in pregnancy.

(1979) cultured it in vitro. Thus, the stage was set for a remarkable era of discovery during which the epidemiology and pathogenesis of both hepatitis A and B were elucidated, and several new actors (hepatitis C, D, E, and G) were recognized. This chapter provides an overview of the clinical and epidemiological features of these various infections and specifically addresses the pathogenesis and pathology of the resulting liver disease (Table 18.1).

ORALLY ACQUIRED SHORT-INCUBATION-PERIOD ACUTE HEPATITIS The viruses of hepatitis A (HAV) and hepatitis E (HEV) cause a morphologically identical hepatic inflammatory disease of relatively short duration that almost invariably resolves without persistent liver damage. Both viruses are transmitted by the fecal-oral route and have an incubation period ranging from 15 to 60 days. Hepatitis A Virus (HAV) Hepatitis A is caused by a small (27 nm in diameter) RNA-containing virus that is structurally and biochemically similar to the enteroviruses and rhinoviruses (i.e., picornaviruses) (see Chapters 1 and 2) (Figure 18.1). Because of its unique characteristics, HAV has been assigned to a new genus termed hepatavirus. Although HAV causes hepatitis in various spe-

cies of subhuman primates, one of the features that distinguishes it from other picornaviruses is the reluctance of the virus to grow in and destroy (i.e., cause the cytolysis of) cultured cells of a diversity of types in the laboratory. It is perhaps incorrect to refer to HAV in the singular form, since at least seven antigenically identical but biologically dissimilar genotypes of the virus have been recovered from humans around the globe. HAV has a worldwide distribution. The overall prevalence of infection inversely correlates with the socioeconomic status of the community, and thus the potential for pollution of water sources by raw sewage. In the developed countries of North America and Europe, HAV is a sporadic cause of illness in persons of all ages, and the majority of the population lack serological evidence of infection. On the other hand, infection invariably occurs at a relatively early age in developing countries, and most adults possess serum antibodies as an indication of a prior infection earlier in life. Thus, the epidemiological features of HAV resemble the common human enteroviruses to which it is closely related. Hepatitis due to HAV is an acute necro-inflammatory disease that usually resolves without clinical complications after an illness in adults of a few weeks duration. Infections in young children commonly are asymptomatic and anicteric. The incubation period in adolescents and adults ranges from 2 to 6 weeks. Typically acquired by the oral route, the virus makes its way to the liver by an as-of-yet undefined route where it replicates in hepatocytes without obvious cytolytic effects. A brief period of viremia and excretion by

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FIGURE 18.1 HAV particles demonstrated by immune electron microscopy. These particles can be demonstrated in suspensions of stool during the acute stages of hepatitis. Bar = 100 nm. Reprinted with permission and through the courtesy of J. Marshal, PhD, and I. Gust, PhD.

means of the biliary tract begins before the onset of clinical illness. To the best of our knowledge, cells of other major organs do not support growth of this virus. Although definitive clinical and experimental evidence is lacking, hepatitis A may be the outcome of immune-mediated disease attributable to cytotoxic CD8+ T cells or the cytochemicals generated by the inflammatory response (Vallbracht et ah, 1989). The disease is characterized by the accumulation of T and B cells and, to an extent, plasma cells and neutrophils in the portal triads, where they are intimately associated with hepatocytes (Polotsky et ah, 1996). The cells of the liver microscopically are somewhat in organizational disarray, and, to a variable extent, ballooning of the cytoplasm or evidence of apoptosis is seen. The "ballooned" hepatocyte exhibits cytoplasmic rarefaction, and the cells may ultimately undergo necrosis. The apoptotic cell shrinks and assumes a more geometric configuration with an eosinophilic dense cytoplasm and a pyknotic nucleus. These so-called acidophilic bodies are then extruded in the sinusoids, where they are often phagocytized. Kupffer cells lining the sinusoids become prominent and exhibit accumulations of lipofuscin, which represents the residua of phagocytized necrotic or apoptotic cells. Cholestasis is a variable feature. With the passage of time, evidence of liver parenchymal damage is accompanied by the features of hepatocyte regeneration in the form of mitotic activity, and binucleate hepatic parenchymal cells are commonly observed. Recovery generally is complete 3 months after the onset of illness.

As noted above, HAV is not directly cytolytic for cultured primate cells, in contrast to its close relatives, the enteroviruses. In HAV-infected humans, maximal excretion of virus in the stools occurs 14 days before peak serum concentrations of glutamic pyruvic transaminase (SGPT) are found in the blood. Evidence of virus excretion via the gut continues during convalescence (Krugman et a/., 1959; Thornton et ah, 1975; Mao et al, 1980). Based on these observations, one might conclude that injury to the liver cells is not caused by the virus. The presence of HAV-sensitized CD8+ cells in the liver during acute episodes of hepatitis strongly suggests that hepatocyte injury is due to the cytolytic T cell response or the products of these cells (Vallbracht et al., 1989). Humoral immunity does not appear to be involved. The mechanisms whereby the cytoplasm of cells balloon, or apoptosis occurs, are poorly understood. These are two different mechanistic disease processes. Fulminating necrosis of the liver parenchyma develops on only the rarest of occasions in persons infected with HAV (Lee, 1993).

Hepatitis E Virus (HEV) Hepatitis E is believed to be caused by an as-yet unclassified small RNA virus having morphologic features of the calicivirus, and certain molecular characteristics of rubella virus (Krawczynski, 1993; Reyes, 1993). Like other hepatitis viruses, HEV replicates and

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causes liver disease in a variety of subhuman primates. It also grows with great reluctance in cultured cells, and does not directly cause cytolytic damage to the liver in vivo. The epidemiology of HEV differs from HAV. Although detailed information worldwide is still lacking, it appears to be a major cause of both waterborne epidemics of sizable proportions and sporadic cases of hepatitis in developing countries, particularly in subSaharan Africa, the Indian Subcontinent, and Southeast Asia. HEV is a rare cause of hepatitis in the United States and Europe, where it primarily occurs among i.v. users of drugs. Although clinical illness customarily develops in adolescents and young adults in endemic areas of the world, subclinical or anicteric hepatitis seems to occur commonly in children. Serological evidence of infection in endemic regions is found in fewer than a third of the older members of the adult population. This may be due to waning immunity with the passage of time among persons infected in childhood. In areas of the world where clinical hepatitis due to HEV rarely, if ever, occurs, serological evidence of subclinical infection is found in a small proportion of the population. The meaning of this finding remains to be

resolved. It may only indicate that residents of developed countries are infected commonly with an antigenically similar, but as yet unidentified virus of no known health importance. The incubation period of HEV is 40 days on average, but there is great variability. In contrast to HAV, the viremia is more protracted. The virus is excreted from the liver by means of the biliary tract into the gut. HEV hepatitis is customarily more severe than the liver disease due to HAV, and the clinical course is more protracted. While the fatality rate is low, pregnant females are at particular risk, with a high mortality in the third trimester (20-40%) and a high rate of spontaneous abortion. The basis for this tragic outcome associated with gestation is unknown (Asher et ah, 1990). The hepatitis of HEV is similar to HAV microscopically, but chronic cholestasis is a common feature. The liver parenchymal cells also tend to be organized in pseudoglandular arrays. This particular morphologic feature served as the basis for the conclusion in the early 1960s that an epidemic of hepatitis in Ghana was due to a new and unique virus. This suspicion, based on the morphology of the liver disease, was proven to be correct many years later.

FIGURE 18.2 A large HBsAg immune complex in the liver homogenate digested with Pronase and reacted with HbsAb. Some of the long filaments are thick, but the others appear to show headings. There are many more small HBsAg positive particles. Five Dane particles (arrows) show rupture of the envelope, thus partially exposing the inner core particles. There are two uncoated virus-like particles (V) having identical morphology with the internal core of Dane particles. The inset shows a tadpole form composed of a Dane particle and a tail filament in an immune complex. The electron opaque spherical bodies are artifacts. Reprinted with permission from Huang and Groh (1973).

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PARENTALLY ACQUIRED LONG-INCUBATION-PERIOD ACUTE A N D CHRONIC HEPATITIS Hepatitis B Virus (HBV) Few experiments in medicine illustrate better the role of serendipity in science than the discovery of HBV. In 1963, Baruch Blumberg, a medical anthropologist, was exploring the geographic distribution of inherited polymorphic traits when he detected a novel antigen in the blood of a native Australian that reacted with antibodies found in the serum of an adolescent American with hemophilia who had been the recipient of multiple blood transfusions. The antigen proved to be common in the blood of Africans and Asians, but was infrequently found in North Americans and residents of Europe. Over the ensuing years, the common presence of the antigen in the blood of patients with acute and chronic clinical hepatitis B was demonstrated. Much additional research showed that Australian antigen was, in fact, the surface antigen of a new virus family, the hepadnaviridae, now etiologically linked with clinical hepatitis of the type having a prolonged incubation period (Figure 18.2). HBV turned out to be the only human pathogen of this new family, but viruses strikingly similar to it are found in wild North American woodchucks, ground and tree squirrels, herons, and domestic ducks. Infections in these animals now serve as models of HBV in humans. Since useful cell culture methodologies for growing this virus in vitro have not yet been developed, large amounts of purified virus have not been available for scientific study.

The HBV virion, 42 nm in diameter, has as its genetic material a partially double-stranded circular DNA that encodes four genes (Figure 18.3A,B). One of these genes is responsible for the protein coat of the virion (i.e., Australian antigen or HBsAg), and the second codes the template for the viral DNA core (HBcAg). There is also the X gene that encodes regulatory proteins responsible for increasing by many fold the expression of a variety of viral and cellular genes, and a gene encoding the polymerase that catalyzes DNA replication. This latter enzyme is unique to the hepadnaviridae, for it makes possible the reverse transcription of an RNA pregene to DNA. In humans and experimentally infected chimpanzees, the virus is found predominantly in hepatocytes, but it can also be detected in low concentrations in blood mononuclear cells and several internal solid organs, but little is known about the biology of the infection outside of the liver. Multiplication of HBV in the hepatocyte follows attachment of the virus to the cell plasma membrane and uptake into the cytoplasm by mechanisms yet to be defined. The viral receptor on the cell surface has not been identified. Intracellular virion replication is a complex event because it depends on reverse transcription of the genomic DNA to an intermediary pregenomic RNA, which in turn is responsible for DNA synthesis. These events occur in the nucleus of the infected hepatocyte. The virion is further assembled in the cytoplasm by budding through intracellular membranes. The glycoprotein membrane is acquired during this step. Intracellular recycling of these events also occurs, thus amplifying multiplication of viral progeny. Although the cells' synthetic mechanisms are profoundly committed to virus replication, the hepato-

"™-HBsAg (Envelope) —HBcAg/HBeAg {Nucleocapsid) [—DNA polymerase --Circular DNA (HBV genome)

-~-™-? X protein FIGURE 18.3 (A) HBV particles in the blood as demonstrated by negative staining immune electron microscopy (122,000x). Reprinted with permission from Huang and Groh (1973). (B) Schematic representation of HBV illustrating key antigenic components. Reprinted with permission from Gerber and Thung (1985).

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FIGURE 18.4 (a) ''Ground glass" hepatocytes in a liver biopsy from a patient with asymptomatic chronic hepatitis, (b) Hepatocytes stained by immunochemistry to identify HBsAg. Reprinted with permission from Afroudakis et ah (1976).

cytes of the infected liver do not lyse as a result. In general, HBsAg is synthesized in excess; it accumulates in the cytoplasm, resulting in the typical ground-glass appearance of the infected cell cytoplasm (Figure 18.4). It also spills over into the blood, where it is found as the pleomorphic spherical and tubular noninfectious antigen particles known as Australian antigen (see Figure 18.2). Customarily, these particles are intermixed with variable numbers of the so-called Dane particles, which are the true virions of HBV in the blood. In the developed countries of North America and Europe, HBV is transmitted in blood products and by the needles and syringes used by consumers of illicit addictive drugs. Sexual interactions are an additional means of transmission, but the mechanism involved is not understood. With rigorous but highly effective screening of blood products for transfusion, new infections are now almost exclusively limited to the subculture of drug abusers and those who engage in promiscuous sexual activity. Many of these individuals are also HIV-1 positive. Subclinical, anicteric hepatitis proves to be the rule in infants and children. Asymptomatic anicteric hepatitis occurs in roughly 60 to 80% of those acquiring the virus during adulthood. The remainder exhibit chemical or overt clinical acute hepatitis after latency periods of 1.5 to 4 months. While the majority of patients recover after variable periods of illness without significant liver damage, about 1% develop fatal fulminating hepatitis with massive destruction of the liver. The disease in a small number (2-10%) evolves into chronic

hepatitis. The risk of a chronic infection inversely relates to age. Ninety percent of infants infected in the perinatal period fail to clear the virus, whereas only 10% of newly infected adults develop chronic disease. These clinical conditions and their pathogenesis will be considered below. In subSaharan Africa, Southeast Asia, the People's Republic of China, and the Mediterranean Basin, transmission of HBV commonly occurs during the perinatal period. The likelihood that the infant will be infected at the time of parturition relates to the replicative activity of the virus in the mother at the time and, consequently, her virus load. The means by which the virus is transmitted from mother to infant are not well defined, but transplacental infection is likely, and bleeding at the time of birth must result in infection of some newborns. Presumably, the immature immune system of the very young child permits the virus to replicate and spread in the liver without a significant protective response. Infection of newborns is common, and 90% of these infants develop chronic hepatitis. In contrast, only 30% of children exposed after the perinatal period, but before the age of 6 years, develop chronic liver disease. Worldwide, over 2 x 10^ people are chronically infected with HBV. The pathogenesis of HBV hepatitis has been the subject of considerable research. The availability of animal models, including transgenically infected mice, and an abundance of clinical information from naturally infected humans, has made major advances possible.

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However, despite the elegance and comprehensiveness of the investigative work, gaps of considerable magnitude preclude a full appreciation of the pathogenesis of clinical hepatitis and the variable outcomes in humans of different ages and societies. Our current understanding of the mechanisms involved in HBV hepatitis are summarized in great detail in a recent review by Chisari and Ferrari (1997). The evidence now indicates that cellular immune mechanisms are key factors in the development of the hepatic lesions. CD8+ cytolytic T cells appear to be the major actors. These cells directly interact with HLA class I-expressing hepatocytes that are endogenously generating the virus. As a consequence, two independent mechanisms of cell injury may be invoked, resulting in either apoptosis or cytolysis of the liver cells (Figures 18.5 and 18.6). The first is a direct consequence of the actions of at least two types of molecules released after contact of the effector lymphocyte with its target, the infected hepatocyte. The pore-forming perforins and a lymphocyte-specific granular serine esterase are the products released by the T cells that are believed to cause cytolysis of the

hepatocytes. Apoptosis, on the other hand, may be due to a Fas-based mechanism, whereby receptors on infected target cells interact with the Fas ligands of the effector T cell (Figure 18.7). The complex mechanisms involved in these events have been recently reviewed (Schulte-Hermann et ah, 1995; Moretta, 1997). Presumably, through cytolysis or apoptosis of the hepatocyte, the infection is terminated. Regenerating liver cells are protected from reinfection either by means of cellular or humoral immune mechanisms. Contemporary thinking suggests that certain cellularly immune mechanisms downregulate the infections in the liver cells. However, direct evidence indicating that this occurs in human HBV hepatitis is currently lacking.

FIGURE 18.6 Liver of a patient infected with HCV. Note the apoptotic hepatocytes (a) and cells exhibiting ballooning of the cytoplasm (b). These are the two major nonspecific changes observed in liver parenchymal cells during hepatitis.

cytotoxic lymphocyte macrophages lymphocytes

EXECUTION

FIGURE 18.5 Electron micrograph of an apoptotic body derived from liver cells. Note the infiltrating lymphocyte (L). The hepatocyte (H) at the top of the figure appears to be unaffected. The electrondense granules in the hepatocyte are glycogen. Reprinted with permission from Ishak (1994).

HEPATOCYTE

FIGURE 18.7 Three major factors are believed to contribute to apoptosis and death of liver cells. TGFp and TNF may interact with plasma membrane receptors, resulting in cell injury. The FAS ligand also can interact APO-FAS to promote apoptosis. DAG = diacylglycerol; TCR = T cell receptor; CTL = cytotoxic lymphocytes. Reprinted with permission from Schulte-Hermann ei al. (1995).

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While the above mechanisins most probably account in whole, or in part, for cell injury and recovery as a consequence of HBV infection in the liver of adults, the pathogenic basis for chronic hepatitis remains poorly understood. In neonatally infected infants, immunologic tolerance would appear to be the likely explanation, but in the adult with chronic hepatitis our understanding is less clear.

Hepatitis D Virus (HDV) (Delta Agent) About 1% of those infected with HBV develop acute liver failure associated with massive hepatic necrosis. Roughly 10% of newly infected adults and a much larger percentage of infants progress to chronic hepatitis, as noted above. When patients with unresolved HBV infections manifest fulminating necro-inflammatory disease or chronic hepatitis that evolves into cirrhosis, the possibility of a superinfection with the delta agent (HDV) is a consideration (Rizzetto el al, 1983; Lee, 1993; Smedile ei al, 1982). HDV is a defective virus that relies on HBV to provide its envelope protein. Thus, it parasitizes the intracellular synthetic systems of the HBV-infected cell to complete its own replicative cycle. This allows the virus to spread from cell to cell. HDV is a small (36 nm in diameter) virion that has a limited store of genetic material in a single strand of RNA that is circularized when located in liver cells (Wang ei al., 1986). While HDV is cosmopolitan in its distribution, it is usually found when the HBV carrier status of a population is relatively high, or when i.v. drug use is prevalent. However, it has also been associated with outbreaks of severe hepatitis among native populations in South America, where these risk factors are not found (Adler ei al., 1984; Ljunggren ei al., 1985; Fonseca and Simonetti, 1987). The means whereby the virus was introduced into these isolated native populations is obscure, and it is not known how the virus spreads from person to person in this setting. In developed areas such as the United States and Western Europe, fewer than 20% of the blood donors who have evidence of chronic HBV infections are also infected with HDV The acute hepatitis due to HBV cannot be dififerentiated clinically and pathologically from HBV associated with HDV (Verme ei al., 1986). Evidence of infection is detected by immunohistochemistry, or by means of in siiu hybridization. Generally, only a small proportion of the liver cells of patients with acute HBV hepatitis are positive for HDV The virus is found more commonly in the livers of patients with chronic hepatitis and cirrhosis. Not surprisingly, chronic hepatitis is the

outcome in about 20 to 25% of HDV-infected patients, and the disease frequently progresses to cirrhosis in these individuals (Rizzetto ei al., 1983). Like other hepatitis viruses, HDV is not cytolytic in vitro, and the mechanism whereby it causes liver cell injury is not understood. Hepatitis C V i m s (HCV) Before the discovery of HCV in 1989, approximately 20 to 25% of recipients of blood transfusions in urban North America and Europe developed the so-called non-A and non-B hepatitis, that is, acute hepatitis of unknown but presumptive viral etiology. More than 80% of these infections progressed to chronic hepatitis, and in a few the disease evolved into cirrhosis and hepatocellular carcinoma. By screening cDNA "expression" vectors derived from RNA in the plasma of chimpanzees inoculated with serum from patients with non-A/non-B hepatitis, clones of a new virus, termed HCV, were found. This finding, the outgrowth of a truly unique laboratory approach to viral diagnosis, was followed by an extraordinary effort to elucidate the biology of HCV and establish its clinical and epidemiological features. The development of several efficient blood screening methodologies has now largely eliminated this virus as a threat for the recipient of blood transfusions. At present, HCV is unclassified virologically, but it possesses many of the molecular and structural features of members of the flaviviridae family (see Chapters 19 and 24) (Cuthbert, 1994). It is a 30- to 34-nm-indiameter enveloped virus having a single-stranded RNA genome surrounded by an envelope derived from the cell in which it grows. The virus has not been successfully grown in cultured cells; thus, much of the information we possess today is derived from investigations conducted in experimentally infected chimpanzees. HCV has a long open reading frame that contains genomic material for the synthesis of several component proteins of the virion, and one of these genes is highly mutable. Accordingly, as many as 12 genotypes of HCV have already been identified, and because of the high mutation rate, it is quite likely that new mutations appear in the patients as a virus adapts to its host. Thus, changes in the antigenicity of the virus may account for the chronicity of the infection as the virus eludes the infected person's immune response. Although immunologic studies at present are limited, both humoral and cellular immune mechanisms are involved in the host's response to infection. However, there is presently no evidence to suggest that the lesion in the liver of the HCV-infected patient has an immunopathologic basis, as is the case in HBV infection. As

Hepatitis Viruses

would be expected, the humoral immune response does not have the capacity to resolve the infection when the virus is sequestered in hepatocytes. Indeed, humoral immunity may promote selection of new pathogenic mutants in vivo on an ongoing basis. Worldwide, the incidence of HCV infection as assessed by immunologic surveys of the population varies. In Scandinavia, fewer than 1% of the general population are infected, whereas in Egypt a prevalence of 12% has been reported. Four million An\ericans are currently believed to be chronically infected with HCV and approximately 8 x 10^ to 1 x 10^ deaths occur annually as a result of this infection. The great majority of infections with HCV have, in the past, resulted from blood transfusions, but transplacental infection of the fetus and perinatal infections are documented (Lin et ah, 1994; Ohto et ah, 1994; Tovo et al, 1997), particularly in the offspring of women with high blood concentrations of virus. Sexual transmission has not been established as a mode of spread, but evidence of familial clustering of seroreactivity exists and female sex workers who have not been the recipients of blood transfusions exhibit a higher incidence of seroreactivity to the

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virus than do female members of the general population. After exposure, HCV RNA is detected in the blood within 1 to 3 weeks. Studies in chimpanzees have shown that concentrations of virus in the liver are exceedingly high at this time. Evidence of liver cell injury in the form of increased blood levels of serum alanine aminotransferase is demonstrated, but most patients are asymptomatic and jaundice develops infrequently. An occasional patient complains of malaise, weakness, and anorexia, and a few become anoretic. The morphological features of the acute disease are illustrated in Figure 18.8. Only about 15 to 25% of patients appear to recover, whereas the remainder enter the chronic hepatitis stage during which an insidious progression of liver disease evolves over a period of decades. Nonspecific symptoms of hepatitis are noted by the occasional patient with chronic HCV hepatitis, but the disease is rarely symptomatic, and almost never disabling. Over a period of two or more decades, about 20% of patients with chronic hepatitis due to HCV develop cirrhosis, and roughly 5% of these patients subsequently develop hepatocellular carcinoma. It is likely that differences in

FIGURE 18.8 (A) Chronic hepatitis. Note the subtle disorganization of the liver parenchyma and the accumulation of lymphocytes adjacent to a necrotic hepatocyte. (B) Prominent "balloon" degeneration of hepatocytes. Note the inflammatory cells and the "dropout" of liver parenchymal cells. (C) Note the aggregates of lymphoid cells in the portal areas. (D) At higher resolution, the lymphoid cell accumulations in the liver illustrated in A encompass bile ducts. Note the normal appearance of the glycogenated cytoplasm of the hepatocyte. Reprinted with permission from Ishak (1994).

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the pathogenicity of virus strains may account for differing degrees of disease progression. Cofactors influencing host susceptibility to the infection most probably are also an important consideration. Patients infected with both HBV and HCV seem to develop progressive disease frequently (Hytiroglou ei al., 1995). Alcoholic beverage consumption in excess is believed to be a risk factor. Although intravenous drug users with HIV-1 also develop HCV infections, HIV-1 does not appear to significantly influence the course of the disease. While fulminating hepatitis is a rare complication of HCV infection, an occasional liver transplant recipient will develop rapidly progressive hepatic disease due to the virus. Currently, a substantial proportion of the liver transplantations done in the United States are due to HCV liver damage. Recurrence of HCV infections in the grafted livers invariably occurs after transplantation. Interestingly enough, in one study the infection did not affect the life expectancy of the graft recipient over a 4-year period, but there was a higher incidence of graft rejection among HCV-infected patients (Lumbreras ei al., 1998). The majority of the recipients of these liver transplants exhibit a relatively benign course. This contrasts with the substantial mortality observed in liver transplant patients infected with HBV (Lake and Wright, 1991). The majority of the recipients of these liver transplants exhibit a relatively benign course. In one study, moderately severe chronic hepatitis developed after transplantation in 27% of patients over the 3-year period, and cirrhosis was found after a latency period of 4 years in 8% (Cane ei al., 1996). An etiological association of mixed cryoglobulinemia with HCV chronic hepatitis is now established (Ferri ei al, 1991; Agnello ei al, 1992). Most Italian patients with mixed cryoglobulinemia appear to possess HCV antibodies, but in the United States the prevalence is somewhat lower (Levey ei al, 1994). These patients exhibit petechial hemorrhages and ecchymoses in the skin of the lower extremities, and often have arthralgias, hepatosplenomegaly and glomerulonephritis. In the serum, viral RNA and virions are complexed with the cryoproteins. Three clinical categories of cryoglobulinemia have been identified (Brouet ei al, 1974). In type I, the immunoglobulins are homogenous and monoclonal. They are generally the result of a lymphoproliferative disorder such as multiple myeloma or Waldenstrom's macroglobulinemia. In the type II form, mixtures of a monoclonal immunoglobulin with anti-IgG activity (rheumatoid factor) and polyclonal IgG are found. Most cases of HCV-associated cryoglobulinemia are of this type (Agnello ei al, 1992). In the type III form, a mixture of heterogenous, and

polyclonal IgM and IgG molecules are present in the blood. Type II is associated with a diversity of infectious processes and autoimmune diseases (Bloch, 1992). The pathogenesis of cryoglobulinemia in HCV is obscure. Other forms of hepatic disease do not produce these profound abnormalities of serum proteins. About 15% of transfusion-associated hepatitis is not attributable to HBV and HCV, and it is not due to HAV or HEV. In 1967, a candidate virus was isolated from the blood of a surgeon (whose initials were G. B.) with acute hepatitis. The virus, which proved to be a flavivirus, was similar to HCV, for it was found to induce hepatitis in marmosets, a small New World primate. With further study, the agent proved to be not one but two viruses, termed GBV-A and GBV-B. These agents now appear to be indigenous to Tamarin monkeys and may be members of an entirely new, previously unrecognized genus of flaviviruses (Bukh and Apgar, 1997). Later, a third, similar virus, GBV-C, was isolated from patients (Fiordalisi ei al, 1996) with hepatitis, and a fourth, designated HGV, was similarly recovered (although it may be a genotype of GBV-C). The discovery of this confusing plethora of incompletely characterized viruses created a stir in the hepatitis research community, but it may be that the interest was unwarranted. Despite the persistence of these viruses in humans, and their association with HCV infections, the GB viruses do not appear to cause hepatitis in humans and do not play a copathogenic role with HCV in enhancing the severity of the liver disease (Alter ei al, 1997; Colombatto ei al, 1997; Hadziyannis, 1998; Loya, 1996; Brown ei al, 1997). We now know that GBVC / HGV is carried in a chronic viremic state by roughly 1 to 2% of Americans and can be transmitted by transfusion and from mother to offspring (Linnen^f al, 1996; Lin ei al, 1998; Masuko ei al, 1996; Stark ei al, 1996; Thomas ei al, 1997).

C H R O N I C HEPATITIS Chronic hepatitis is a clinical and pathologic syndrome, not a single disease. Patients may be asymptomatic, but more often they experience variable degrees of malaise and fatigue intermittently. Serum concentrations of the liver enzymes alanine and aspartate aminotransferase are usually increased, but alkaline phosphatase and gamma-glutamyl transpeptidase, bilirubin, albumin, and the various coagulation factors are customarily found in normal concentrations. Thus, the synthetic capacity of the liver parenchyma is intact.

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•

W

0 FIGURE 18.9 Chronic hepatitis, low-power assessment of morphologic patterns. (A) Portal hepatitis involves an increase in mononuclear cells (dots), almost entirely confined to portal areas. At scanning magnification, this results in the portal areas being sharply delimited. (B) In periportal hepatitis, an increase in mononuclear cells (dots) in the periportal parenchyma (zone 1) occurs, commonly associated with piecemeal necrosis and lobular inflammation of variable degree. The result is a low-power impression of portal-dominant inflammation; however, the portal areas are less sharply defined than in portal hepatitis. (C) Lobular hepatitis is characterized by lobular inflammation, with or without disarray and necrosis. Pure lobular hepatitis is a feature of acute hepatitis; however, lobular hepatitis in conjunction with considerable portal and periportal inflammation is typical of '"flares" of chronic viral or autoimmune hepatitis. Reprinted with permission from Batts and Ludwig (1995).

Pathologically, chronic hepatitis is defined as a progressive necro-inflammatory disease of variable severity not associated with the features of chronic cholestasis, steatosis, and Mallory body formation (Ishak, 1994) (Figure 18.9). Portal fibrosis, cirrhosis, and, in some cases, hepatocellular carcinoma, are the final outcome. The term "chronic hepatitis'' commits to obsolescence a confusing nomenclature that has accumulated in the field of hepatology since the 1960s (Table 18.2) (Desmet et al, 1994; Party 1995). HBV, with or without the delta agent, and HCV are the common etiologies of chronic hepatitis in most clinical situations, but autoimmune hepatitis is responsible in sporadic cases. Superimposed infections and nutritional or toxic insults to the liver may accentuate the severity of the process. Piecemeal necrosis is the hallmark of chronic hepatitis. It is reflected as the expansive degeneration and destruction of the periportal limiting plate of liver cells, ultimately resulting in the confluence of adjacent portal areas and leading to bridging fibrosis between portal triads. The fibrosis that follows in the wake of the liver parenchymal injury (Figures 18.10-18.12) is progressive and can ultimately terminate in cirrhosis (Figure

18.13). Degenerative changes in individual liver cells consist of either cytoplasmic swelling and rarefaction or the clumping of cytoplasmic organelles (or both). Apoptotic bodies (syn. acidophilic bodies) are also seen (see Figure 18.5). To a variable extent, the portal areas

TABLE 18.2 Chronic Hepatitis and Cirrhosis: Obsolete Terms Chronic hepatitis and related conditions Chronic active hepatitis, chronic aggressive hepatitis, chronic active liver disease, plasma cell hepatitis, lupoid hepatitis, and other synonyms for autoimmune hepatitis Chronic persistent hepatitis Chronic lobular hepatitis Chronic nonsupportive destructive cholangitis Pericholangitis Cirrhosis Portal cirrhosis Postnecrotic cirrhosis Posthepatitic cirrhosis Reprinted with permission from Batts and Ludwig (1995).

264

Pathology and Pathogenesis of Human Viral Disease TABLE 18.3 Scoring S y s t e m for Grading and Staging of Liver S p e c i m e n s w i t h Chronic Hepatitis Grade of necro-inflammatory activity

Stage of fibrosis/ cirrhosis

0 = no necro-inflammatory activity

0 = no fibrosis

1 = mild piecemeal necrosis and lobular activity

1 = mild fibrosis (= portal fibrosis without fibrous septum formation)

2 = moderate piecemeal necrosis and lobular activity

2 = moderate fibrosis (= fibrous septa extending into lobules, but not reaching terminal hepatic venules

3 = Severe piecemeal necrosis and lobular activity with or without bridging necrosis

3 = severe fibrosis (= fibrous septa extending to adjacent portal tracts and terminal hepatic venules, indicating transition to cirrhosis)

and other portal tracts)

4 = cirrhosis Reprinted with permission from Batts and Ludwig (1995).

are infiltrated by B lymphocytes, plasma cells, and macrophages, which, on occasion, accumulate into follicles. Intraacinar infiltrates of inflammatory cells and activated Kupffer cells line sinusoids in the usual histological picture (Figure 18.14). The pathological changes in chronic hepatitis have been categorized semiquantitatively by Batts and Ludwig (1995) into a grading schema for clinical application (Table 18.3; Figure 18.15).

HEPATOCELLULAR CARCINOMA (HCC) (see Figures 18.16-18.19)

Numerous risk factors have been identified that are believed to cause, or contribute to, the development of HCC (Table 18.4). HCC most probably is an example of multistage carcinogenesis in which endogenous and exogenous influences act in concert to transform the hepatocyte, possibly in persons who are genetically

FIGURE 18.10 Post-transfusion HBV with submassive necrosis in a leukemic patient. A tongue of necrotic tissue bridges between lobules of liver. Reprinted with permission from Ishak (1976).

265

Hepatitis Viruses

FIGURE 18.11 Chronic hepatitis. Adjacent portal areas expanded by fibrosis are linked as demonstrated by a reticulin stain that denotes collagen. Reprinted with permission from Ishak (1994).

^"*4SS»%%'i'^V--?vt'*>/'r •'••• •:••

FIGURE 18.12 Marked periportal fibrosis with extension into the lobular structure of liver.

FIGURE 18.13 Nodular cirrhosis secondary to HCV chronic hepatitis. Note the regenerating nodules of liver parenchymal cells separated one from another by bands of connective tissue. Chronic inflammatory cell infiltrates in the fibrous tissue constitute a nonspecific change.

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Pathology and Pathogenesis of Human Viral Disease

FIGURE 18.14 Mixed inflammatory cell infiltrate comprised of lymphocytes, plasma cells, and macrophages in the parenchyma of the liver from a case of chronic HCV infection.

FIGURE 18.15 Staging of chronic hepatitis, schematic diagram. (A) Portal fibrosis (stage 1) characterized by mild fibrous expansion of portal tracts. (B) Periportal fibrosis (stage 2) showing fine strands of connective tissue in zone 1 with only rare portal-portal septa. (C) Septal fibrosis (stage 3) manifested by connective tissue bridges that link portal tracts with other portal tracts and central veins, minimally distorted architecture, but no regenerative nodules. (D) Cirrhosis (stage 4) showing bridging fibrosis and nodular regeneration. Reprinted with permission from Batts and Ludwig (1995).

Hepatitis Viruses TABLE 18.4 Nonviral Risk Factors for Hepatocellular Carcinoma (HCC)

267 TABLE 18.5 Geographic Distribution of H C C 5-20«

20-15(F Aflatoxin Bj contamination of food Alpha 1 antitrypsin deficiency Anabolic and estrogenic steroid consumption Ethanol consumption Hemochromatosis Nutritional deficiencies Thorotrast diagnostic procedures Tobacco smoking

FIGURE 18.16 Extensive involvement of the liver by hepatocellular carcinoma. Note the hemorrhage and necrosis in the large central nodular mass. Elsewhere, the parenchyma is interdigitated by bands of connective tissue of varying thickness. At the resolution of the naked eye, it is often impossible to differentiate neoplastic tumor from cirrhotic liver. Reprinted from Craig et ah (1989).

predisposed. To date, no specific molecular markers have been associated with the transformational event. The pathogenic role of HBV and HCV in the neoplastic process should be considered in this context. Worldwide, some 7 X 10^ HCC deaths occur annually. The incidence of HCC exhibits great geographic variability (Table 18.5), being highest in subSaharan Africa and Southeast Asia, and lowest in the developed countries of Europe and North America. However, pockets of increased prevalence are found where immigrants from endemic areas have settled and retained their traditions as well as the diets of their former homes. HCC in North America is typically a disease of the sixth or seventh decades of life, but in areas of endemicity, it tends to appear clinically at an earlier age. For unknown reasons, HCC occurs predominantly in males in endemic areas of high disease prevalence.

<5"

subSaharan Africa

Mediterranean countries

Europe

Southern China

Japan

North America

Southeast Asia

South America India

Adapted with permission from Anthony (1984). ''Incidence per 100,000 population per year.

FIGURE 18.17 Hepatocellular carcinoma separated into nodules so as to mimic cirrhosis. The cytology of tumor cells is the distinguishing characteristic. Reprinted from Craig et al. (1989).

In regions of the world where HCC is common, HBV infection is acquired by newborns in the perinatal period and persist in the form of chronic antigenemia with smoldering chronic hepatitis for the lifetime of the individual. To the extent that the infection plays a direct role in the causation of HCC, the latency period of this tumor is extraordinarily long. However, in the Orient, occasional cases of HCC are described in young children chronically infected with HBV (Shimoda et al, 1980; Tanaka et ah, 1986), an indication that the latency period need not be long. In the People's Republic of China (Yeh et al, 1989), Taiwan (Beasley et al, 1988), Japan (Ijima et al, 1984; Obata et al, 1980), and in the Alaskan native populations (McMahon et al, 1990), the incidence of HCC is increased 30- to 100-fold in persons chronically infected with HBV. In addition, the HBV genetic material is demonstrated in the cytoplasm of neoplastic cells in over 85% of tumors (Edamoto et al, 1996; Robinson, 1994). Although there is a clear epidemiological association of HBV with HCC, the mechanism of carcinogenesis remains to be fully defined. It has been sug-

268

Pathology and Pathogenesis of Human Viral D i s e a s e

FIGURE 18.18 Hepatocellular carcinoma. Note the nuclear pleomorphism and the loss of orientation of the malignant cells. Atypical mitoses are variable in number. The clear circumscribed bodies contain glycogen. Reprinted from Craig et al. (1989).

FIGURE 18.19 Ground-glass cells in hepatocellular carcinoma. The cytoplasmic changes in the tumor cells mimic "ground-glass" changes in the HBV infected hepatocyte, but immunohistochemistry and electron microscopy show them to be comprised of non-membrane-bound amorphous fibrillary material. HBsAg can occasionally be identified in the cytoplasm of hepatocarcinoma cells, but ground-glass cytoplasmic changes due to HBsAg are a rare finding. Reprinted with permission from Stromeyer et al (1980).

Hepatitis Viruses

gested that HBV is oncogenic, but, as briefly summarized below, the evidence is unconvincing. In those who are chronically infected with HBV, the genome of the virus is integrated in a seemingly random fashion into the DNA of the transformed hepatocyte. These integration sites are usually associated with microdeletions of the cell's DNA, but major changes in the genome are not found. In the tumors, the integrated DNA is monoclonal and detectable in all tumor cells. While this, in fact, proves to be the case, it does not necessarily link the infection causitively with the neoplasm. Indeed, the weakness of the argument that HBV is oncogenic focuses on the lack of specificity of the integration site in the cell chromosomes, and our failure to demonstrate an association of the HBV genome with a critical cellular gene(s) recognized to be intrinsic to the process of carcinogenesis. Regardless, skepticism is sobered by the fact that woodchucks and ducks infected with their specific hepadnavirus almost routinely develop HCC when maintained in captivity in the absence of other possible liver carcinogens. One might speculate regarding alternate mechanisms whereby HBV contributes to the development of HCC. First, a component of the integrated genome of HBV might serve as an independent protooncogene initiating the neoplastic process by a mechanism yet to be defined. Although an attractive hypothesis, there is, at present, no evidence to support it. Second, the HBV genome could provide transcriptional transactivating genes that elaborate products which stimulate hepatocyte proliferation. Two such genes that code for the so-called "X'' protein and the pre-S2 activators have been identified (Hildt ei al, 1996). The HBV "X" protein might then inactivate regulatory suppressors such as the p53 gene or stimulate elaboration of positive growth regulators such as the insulin-like growth factors 1 and 2 (Feitelson and Duan, 1997; Kasai et ah, 1996; Kobayashi et ah, 1997). And, finally, chronic inflammation of the liver parenchyma accompanied by ongoing destruction and regeneration (that is, chronic hepatitis) might lead to neoplastic transformation due to the effects of inflammatory cell-generated oxidants on the hepatocyte DNA or possibly the effects of either endogenous or exogenous promoters or cocarcinogens (Grisham, 1995; Brechot et al, 1982; Popper et a/., 1988). Evidence supporting this attractive concept is based, in part, on the demonstrated common occurrence of cirrhosis in HBV-infected persons who develop HCC. Presumably, the tumor originates in one of the regenerating liver nodules found in this lesion. The mycotoxin food contaminant aflatoxin B^ (and related compounds) is an established carcinogen that could play a contributory role in the pathogenesis of

269

HCC. This oncogenic toxin contaminates food supplies almost universally in areas of high HCC endemicity. In one study from a geographic area where HCC is prevalent, urinary excretion of aflatoxin Bi guanine adducts was increased almost eightfold in patients with HCC (Bradbear et al, 1985). Interestingly enough, aflatoxin Bi induces specific mutations of the p53 suppressor gene that are identical to those found in the malignant hepatocyte of HCC (Bressac et al, 1991; Hsu et al, 1991). The etiological role of HCV in the pathogenesis of HCC is now established, based on epidemiological studies worldwide (Resnick and Koff, 1993; Tsukuma et al, 1993) and the consistent demonstration of replicating virus in the cells of the tumor (Sansonno et al, 1997; Tang et al, 1995; Saito et al, 1997; Edamoto et al, 1996). Considerable geographic variability in the prevalence of HCV-associated HCC is found that no doubt relates to differences in the prevalence of the virus infection in different populations. Since only a third of infections can be traced to blood transfusions, social influences determine the proportion of the population that are infected. The number of liver cancers that are related to HCV in the general population ranges from 72% in Spain to 5% in South Africa, with intermediate percentages being documented in Japan, Europe, and North America (Caselmann and Alt, 1996; Kew et al, 1997; Colombo and Covini, 1995). Because of their similar mode of transmission, many patients infected with HCV are also carriers of HBV One might ask whether or not the two viruses can act synergistically to promote viral transformation of the liver. At present, there is no epidemiological or experimental evidence to support such a possibility. We know very little as to how HCV might act to initiate or promote carcinogenesis. There is no evidence to indicate that viral genes are integrated into the hepatocyte DNA, or act either as transactivating substances or oncogenes (el-Refaie et al, 1996). Since the tumor commonly develops after a prolonged latency period (Castells et al, 1995) in persons with chronic hepatitis and cirrhosis (Reigler, 1996; Shiratori et al, 1995; Silini et al, 1996), malignant transformation of cells in regenerating foci in the cirrhotic liver seems to be the most likely explanation. In one study, 43% of HCCs were found to develop in regions of the liver demonstrating nodular regenerative hyperplasia (Nzeako et al, 1996). Alcoholic beverage consumption may be a cofactor in some cases (Kubo et al, 1997; Bruno et al, 1997), and accumulating epidemiological evidence suggests that specific types of HCV are exceptionally pathogenic (Bruno et al, 1997; Tanaka et al, 1996; Hatzakis et al, 1996; Zein et al, 1996).

270

Pathology and Pathogenesis of Human Viral Disease

A U T O I M M U N E HEPATITIS (AH) Approximately 20% of patients with chronic hepatitis in Europe and North America have an autoimmune form of disease unrelated to virus infection (Holdstock ei ah, 1983). AH is a chronic necro-inflammatory idiopathic liver disease associated with autoantibodies against tissue constituents in the blood and high serum IgG blood concentrations (Johnson and MacFarlane, 1993; Krawitt, 1996). Although the etiology(s) is unknown, it appears to be a disease of disordered immune regulation possibly due to defects in suppressor T cell function (Mondelli et al, 1988; Meyer zum Buschenfelde and Lohse, 1995). Since AH is effectively treated with antiinflammatory and immunosuppressive drugs, differentiation from viral hepatitis and other forms of autoimmune liver disease (primary biliary cirrhosis and sclerosing cholangitis) is a critical clinical challenge. However, to the pathologist's eye, there are no discriminating morphologic features that allow one to differentiate AH from severe chronic viral hepatitis (Figures 18.20 and 18.21). However, portal infiltrates of B cells and helper/suppressor T cells are often prominent in this disease. These features may implicate humoral immune mechanisms in the patho-

genesis of AH. AH tends to progress to cirrhosis rapidly in comparison to chronic viral hepatitis. Since the disease is often subtle at the outset, patients often present with advanced hepatic fibrosis or cirrhosis. Hypergammaglobulinemia and autoantibodies are, on occasion, elaborated by patients with chronic hepatitis having a viral etiology, and approximately 10% of patients with viral hepatitis have circulating autoantibodies (Pawlotsky et al, 1993). However, the titers are usually higher in the autoimmune form of the disease. In addition, patients with AH will, on occasion, possess serum antibody evidence of a prior measles or either an HBV or HCV infection (Pawlotsky et a/., 1993). In these patients, low titers of antiviral antibody do not necessarily imply previous infection. AH typically presents subtly as jaundice in a young woman (male:female ratio in some patient series has been as high as 1:8), possessing certain histocompatibility antigen markers (HLA class I B8 class II DR3 or DR4) and a variety of serum autoantibodies (Table 18.6). Commonly, without treatment, these patients evolve to a chronic stage, resulting in progressive liver parenchymal fibrosis and, ultimately, cirrhosis. A variety of other autoimmune disorders may occur concomitantly in the occasional patient.

FIGURE 18.20 Chronic nonviral autoimmune hepatitis with portal inflammation. The arrow points to a cell exhibiting balloon degeneration. Reprinted with permission from Ishak (1994).

271

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FIGURE 18.21 Chronic nonviral autoimmune hepatitis showing extensive bridging fibrosis. Reprinted with permission from Ishak (1994).

TABLE 18.6 Autoantibodies in Autoimmune Hepatitis

Type 1 (classic)

2 (anti-LKM-1)

Characteristically present autoantibodies Antinuclear Anti-smooth muscle Antiactin Anti-asialoglycoprotein receptor Anti-LKM-1 Anti-liver cytosol 1

Autoantibodies occasionally present Antimitochondrial Anti-soluble liver antigen Anti-liver-pancreas protein Antineutrophil cytoplasmic Anti-liver cytosol 1" Antinuclear''

Reprinted with permission from Krawitt (1996). 'Rare.

PAPILLARY ACRODERMATITIS (GIANOTTI-CROSTI SYNDROME; GCS) GCS is a childhood exanthematous papillary-vesicular symmetrical dermatitis of the face and extremities accompanied by inguinal and axillary adenopathy (Figure 18.22). It customarily occurs during the first 5 years of life, resolving after 2 to 3 weeks without residue. The pathogenesis is obscure. Originally described in youngsters with acute hepatitis B (Ishimaru et ah, 1976; Gianotti, 1973; Toda ei al, 1978; San Joaquin et al, 1981; Draelos et al., 1986), it now appears to also be a

complication of a wide variety of other acute viral infections, including Epstein-Barr virus (Hofmann et ah, 1997; Lacour and Harms, 1995; Mempel et al, 1996), cytomegalovirus (Caputo et al, 1992; Tzeng et al, 1995; Haki et al, 1997), parainfluenza and mumps (Hergueta-Lendinez et al, 1996), respiratory syncytial virus, and vaccinia (Hofmann et al, 1997). Pathologically, the cutaneous lesions exhibit nonspecific perivascular histiocytic and lymphocytic infiltrates in the papillary dermis. The enlarged lymph nodes show pleomorphic histiocytic proliferation with a prominence of endothelial cells in the small blood vessels, lymphatics, and

272

Pathology and Pathogenesis of Human Viral Disease

FIGURE 18.22 Papular lesions of Gianotti-Crosi syndrome on the face and extensor surface of the arm. Reprinted with permission from San Joaquin ef fl/. (1981).

sinuses. The enlarged lymph nodes can persist for several months. Apparently, attempts to detect viral antigens and virions in the skin lesions have failed.

GLOMERULONEPHRITIS Glomerulonephritis (GN) now is a well-recognized outcome of HBV antigenemia (Combes et al, 1971). HBV-associated GN (HBGN) develops frequently in children, most often males, and, to a lesser extent, adults in endemic areas where the prevalence of HBV infections in early life is high (Knieser et al, 1974; Morzycka and Slusarczyk, 1979; Ozawa et al, 1976; Southwest Pediatric Nephrology Group, 1985; Hirsch et al, 1981). In Europe and North America, where chronic HBV antigenemia occurs infrequently in members of the general population, HBGN occurs sporadically. Many of the patients are infected during adulthood by blood transfusions or i.v. drug usage. In one study, 20% of children with membranous nephropathy had detectable HBV in the blood. However, the pathogenic role of the virus in the disease of these patients is not clear. The overall prevalence of HBGN in developing countries is not known. Clinically, HBGN commonly presents in children as the nephrotic syndrome usually unaccompanied by significant renal failure. Patients occasionally have an

associated systemic vasculitis that proves to be mediated by immune complex. The occurrence of hepatitis does not appear to be a factor influencing whether or not disease of the kidney occurs. Renal disease in younger patients customarily resolves uneventfully regardless of treatment. About 65% of children with HGBN remit spontaneously before the end of the first year following onset, and 85% are well at the end of the second year (Venkataseshan et al, 1990). Studies of adults with GN and chronic HBV antigenemia yield more ominous findings. In one report from Hong Kong, an HB V-endemic area, almost a third of the adult patients studied had progressive renal failure and 10% required long-term dialysis (Lai et al, 1991). It is likely these patients acquired the infection early in life and had chronic antigenemia over a period of many years. Membranous glomerulonephritis with or without mesangial thickening is the most common form of HBGN. Ultrastructurally, the basement membrane of the glomerular capillaries are irregularly thickened and show glandular subepithelial deposits and the socalled "spikes" (Ito et al, 1981). Mesangioproliferative and diffuse proliferative GN occurs less commonly in children and more frequently in adults. In these cases, sizable subendothelial deposits are found on both sides of the basement membrane and in the mesangium by electron microscopy. Immunohistochemistry demonstrates diffuse or segmental glomerular deposits of IgG, IgM, and IgA, as well as complement components. Abundant accumulations of HBsAg are also found along the capillary walls and occasionally in the mesangium. HBcAg is present in roughly two-thirds of cases, whereas HbeAg is not found commonly (Venkataseshan et al, 1990; Lai et al, 1996). The nature of the antigens and antibodies comprising the immune complex localizing in the glomerulus dictate the timing of the process and the site of deposition in the kidneys. Since three antigens and three types of antibodies may be involved, the pathogenesis of the glomerulitis can be complex. Clearly, the factors determining whether or not GN will develop in an individual patient, and the pathogenic basis for both the morphological features and severity of the lesions, are poorly understood. As noted above, woodchucks are naturally infected with a hepadnavirus (WHV) strikingly similar to HBV. Renal lesions identical to those seen in humans evolve in woodchucks experimentally infected with WHV. This model system provides an exceptionally useful tool for exploring the mechanisms involved in HBGN (Peters et al, 1992). Accumulating evidence suggests that the chronic viremia of HCV may result in immune complex GN. Johnson and colleagues (1993) reported eight patients

Hepatitis Viruses

with chronic HCV infections who had membranoproliferative GN associated with ultrastructurally demonstrable subendothelial and mesangial deposits and consistently accompanied by accumulations of IgM, IgG, and C3 in the glomeruli. Most of these patients had circulating immune complexes containing HCV RNA and cryoglobulins. This evidence suggests a possible immunopathological role for HCV in the GN. Since the investigators did not demonstrate HCV antigenic or molecular components in the glomeruli, the mechanism of the disease in these patients remains uncertain.

References Adler, S., De Monzon, M., Ponzetto, A., et al. (1984). Delta vims infection and severe hepatitis: An epidemic in the Yucpa Indians of Venezuela. Ann. Intern. Med. 100, 339-344. Afroudakis, A., Liew, C , and Peters, R. (1976). An immunoperoxidase technique for the demonstration of the hepatitis B surface antigen in human livers. Am. ]. Clin. Pathol. 65, 533-539. Agnello, v., Chung, R., and Kaplan, L. (1992). A role for hepatitis C virus infection in type II cryoglobulinemia. New Engl J. Med. 327, 1490-1495. Almeida, J., Rubenstein, D., and Stott, E. (1971). New antigen-antibody system in Australia-antigen-positive hepatitis. Lancet 2, 1225. Alter, M., Gallagher, M., Morris, T., Moyer, L., Meeks, E., Krawczynski, K., Kim, J., and Margolis, H. (1997). Acute non-A-E hepatitis in the United States and the role of hepatitis G virus infection. New Engl. }. Med. 336, 741-746. Anthony, P. (1984). Hepatocellular carcinoma: An overview. In "'Virus-Associated Cancers in Africa'' (A. Williams, G. O'Connor, G. De-The, and C. Johnson, eds.), pp. 3-29. Oxford University Press, Oxford. Asher, L., Innis, B., Shrestha, M., Ticehurst, J., and Baze, W. (1990). Virus-like particles in the liver of a patient with fulminant hepatitis and antibody to hepatitis E virus. /. Med. Virol. 31, 229-233. Batts, K., and Ludwig, J. (1995). Chronic hepatitis: An update on terminology and reporting. Am. J. Surg. Pathol. 19,1409-1417. Beasley, R. (1988). Hepatitis B virus: The major etiology of hepatocellular carcinoma [review]. Cancer 61,1942-1956. Bloch, K. (1992). Cryoglobulinemia and hepatitis C virus. New Engl. J. Med. 327, 1521-1522. Bradbear, R., Bain, C , Siskind, V, Schofield, F., Webb, S., Axelsen, E., Halliday J., Bassett, M., and Powell, L. (1985). Cohort study of internal malignancy in genetic hemochromatosis and other chronic non-alcoholic liver disease. /. Natl. Cancer Inst. 75, 81-84. Brechot, C , Nalpas, B., Courouce, A., Duhamel, G., Callard, P., Carnot, R, TioUais, R, and Berthelot, R (1982). Evidence that hepatitis B virus has a role in liver-cell carcinoma in alcoholic liver disease. New Engl. J. Med. 306,1384-1387. Bressac, B., Kew, M., Wando, J., and Oztark, M. (1991). Selective G to T mutations of p53 gene in hepatocellular carcinoma from southern Africa. Nature 350, 429. Brouet, J., Clouvel, J., Damn, R, Klein, M., and Seligmann, M. (1974). Biological and clinical significance of cryoglobulins: A report of 86 cases. Am. ]. Med. 57, 775-788.

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Brown, K., Wong, S., Buu, M., Binh, T., Be, T., and Young, N. (1997). High prevalence of GB virus C/hepatitis G virus in healthy persons in Ho Chi Minh City Vietnam. /. Infect. Dis. 175, 450-453. Bruno, S., Silini, E., Crosignani, A., Borzio, R, Leandro, G., Bono, R, Asti, M., Rossi, S., Larghi, A., Cerino, A., Podda, M., and Mondelli, M. (1997). Hepatitis C virus genotypes and risk of hepatocellular carcinoma in cirrhosis: A prospective study. Hepatology 25, 754-758. Bukh, J., and Apgar, C. (1997). Five new or recently discovered (GBVA) virus species are indigenous to New World monkeys and may constitute a separate genus of the Flaviviridae. Virology 229, 429436. Caputo, R., Gelmetti, C , Ermacora, E., Gianni, E., and Silvestri, A. (1992). Gianotti-Crosti syndrome: A retrospective analysis of 308 cases. /. Am. Acad. Dermatol. 26, 207-210. Caselmann, W, and Alt, M. (1996). Hepatitis C virus infection as a major risk factor for hepatocellular carcinoma. /. Hepatol. 24 (Suppl. 2), 61-66. Castells, L., Vargas, V, Gonzalez, A., Esteban, J., Esteban, R., and Guardia, J. (1995). Long interval between HCV infection and development of hepatocellular carcinoma. Liver 15,159-163. Chisari, R, and Ferrari, C. (1997). Viral hepatitis. In "Viral Pathogenesis" (N. Nathanson, R. Ahmed, F. Gonzalez-Scarano, D. Griffin, K. Holmes, F. Murphy, and H. Robinson, eds.), pp. 745-778. Lippincott-Raven, Philadelphia. Colombatto, P., Randone, A., Civitico, G., Monti-Gorin, G., Dolci, L., Medaina, N., Calleri, G., Oliveri, R, Baldi, M., Tappero, G., Volpes, R., David, E., Verme, G., Smedile, A., Bonino, R, and Brunetto, M. (1997). A new hepatitis C virus-like flavivirus in patients with cryptogenic liver disease associated with elevated GGT and alkaline phosphatase serum levels. /. Viral Hepatitis 4 (Suppl. 1), 55-60. Colombo, M., and Covini, G. (1995). Hepatitis C virus and hepatocellular carcinoma. Clin. Exp. Rheumatol. 13 (Suppl. 13), S23-S27. Combes, B., Stastny, P., Shorey, J., Eigenbrodt, E., Barrera, A., Hull, A., and Carter, N. (1971). Glomerulonephritis with deposition of Australia antigen-antibody complexes in glomerular basement membrane. Lancet 2, 234-237. Craig, J., Peters, R., and Edmonson, H. (1989). Tumors of the liver and intrahepatic bile ducts. AFIP Tumor Fasicle. Cuthbert, J. (1994). Hepatitis C: Progress and problems. Clin. Microbiol. Rev. 7, 505-532. Desmet, V, Gerber, M., Hoofnagle, J., Manns, M., and Scheuer, P. (1994). Classification of chronic hepatitis: Diagnosis, grading and staging. Hepatology 19,1513-1520. Draelos, Z., Hansen, R., and James, W. (1986). Gianotti-Crosti syndrome associated with irifections other than hepatitis B. JAMA 256, 2386-2388. Edamoto, Y, Tani, M., Kurata, T., and Abe, K. (1996). Hepatitis C and B virus infections in hepatocellular carcinoma: Analysis of direct detection of viral genome in paraffin embedded tissues. Cancer 77, 1787-1791. el-Refaie, A., Savage, K., Bhattacharya, S., Khakoo, S., Harrison, T., el-Batanony, M., Soliman, E., Nasr, S., Mokhtar, N., Amer, K., Scheuer, P., and Dhillon, A. (1996). HCV-associated hepatocellular carcinoma without cirrhosis. /. Hepatol. 24, 277-285. Feinstone, S., Kapikian, A., and Purcell, R. (1973). Hepatitis A: Detection by immune electron microscopy of a virus-like antigen associated with acute illness. Science 182,1026. Feitelson, M., and Duan, L. (1997). Hepatitis B virus X antigen in the pathogenesis of chronic infections and the development of hepatocellular carcinoma. Am. ]. Pathol. 150,1141-1157.

274

Pathology and Pathogenesis of Human Viral Disease

Ferri, C , Greco, R, Longombardo, G., Pallo, P., Moretti, A., Marco, E., Fasello, P., Pasero, G., and Bombadiere, S. (1991). Antibodies against hepatitis C virus in mixed cryoglobulinemia patients. Infection 19, 417-420. Fiordalisi, G., Zanella, I., Mantero, G., Bettinardi, A., Stellini, R., Paraninfo, G., Cadeo, G., and Primi, D. (1996). High prevalence of GB virus C infection in a group of Italian patients with hepatitis of unknown etiology. /. Infect. Dis. 174,181-183. Fonseca, J., and Simonetti, J. (1987). Epidemiology of the hepatitis delta virus (HDV) in Brazil. In 'The Hepatitis Delta Virus and Its Infection'' (M. Rizzetto, J. Gerrin, and R. Purcell, eds.), pp. 507514. Alan R. Liss, New York. Gane, E., Portmann, B., Naoumov, N., Smith, H., Underbill, J., Donaldson, P., Maertens, G., and Williams, R. (1996). Long-term outcome of hepatitis C infection after liver transplantation. New Engl. ]. Med. 334, 815-820. Gerber, M., and Thung, S. (1985). Molecular and cellular pathology of hepatitis B. Lab. Invest. 52, 572-590. Gianotti, F. (1973). Papular acrodermatitis of childhood: An Australia antigen disease. Arch. Dis. Child. 48, 794-799. Grisham, J. (1995). Liver. In "Pathology of Environmental and Occupational Disease" (J. Craighead, ed.), pp. 491-509. Mosby, St. Louis. Hadziyannis, S. (1998). Fulminant hepatitis and the new G/GBV-C flavivirus. /. Viral Hepatitis 5,15-19. Haki, M., Tsuchida, M., Kotsuji, M., lijima, S., Tamura, K., Koike, K., Izumi, I., Tanaka, M., and Hirano, T. (1997). Gianotti-Crosti syndrome associated with cytomegalovirus antigenemia after bone marrow transplantation. Bone Marrow Transplant. 20, 691-693. Hatzakis, A., Katsoulidou, A., Kaklamani, E., Touloumi, G., Koumantaki, Y, Tassopoulos, N., Karvountzis, G., Gioustozi, A., Hadziyannis, S., and Trichopoulos, D. (1996). Hepatitis C virus lb is the dominant genotype in HCV-related carcinogenesis: A case-control study. Int. ]. Cancer 68, 51-53. Hergueta-Lendinez, R., Pozo-Garcia, L., Alejo-Garcia, A., RomeroCachza, J., and Gonzalez-Hachero, J. (1996). Gianotti-Crosti syndrome due to a mixed infection produced by the mumps virus and the parainfluenza virus type 2. Anales Espanoles de Pediatria 44, 65-66. Hildt, E., Hofschneider, P, and Urban, S. (1996). The role of hepatitis B virus (HBV) in the development of hepatocellular carcinoma. Sem. Virol. 7, 333-347. Hirsch, H., Ainsworth, S., DeBeukelaer, M., Brissie, R., and Hennigar, G. (1981). Membranous glomerulonephritis in a child asymptomatic for hepatitis B virus: Concomitant seropositivity for HBsAG and Anti-HBs. Am. J. Clin. Pathol. 75, 597-602. Hofmann, B., Schuppe, H.-C, Adams, O., Lenard, H.-G., Lehmann, P., and Ruzicka, T. (1997). Gianotti-Crosti syndrome associated with Epstein-Barr virus infection. Pediatr. Dermatol. 14,17?>-T77. Holdstock, G., Rassam, S., Millward-Sadler, G., and Wright, R. (1983). Different aetiology of chronic active hepatitis in U.K. and Iraq. Liver 3, 2-7. Hsu, I., Metcalf, R., Sun, T., Welsh, J., Wang, N., and Harris, C. (1991). Mutational hotspot in the p53 gene in human hepatocellular carcinoma. Nature 350, 427. Huang, S., and Groh, V. (1973). Immunoagglutination electron microscopic study on virus-like particles and Australia antigen in liver tissue. Lab. Invest. 29, 353-366. Hytiroglou, P., Dash, S., Haruna, Y, Fernandez, M., Theise, N., Schwartz, M., Miller, C , Bodenheimer, H., Thung, S., and Gerber, M. (1995). Detection of hepatitis B and hepatitis C viral sequences in fulminant hepatic failure of unknown etiology. Am. ]. Clin. Pathol 104, 588-593.

Ijima, T, Saitoh, N., Nobotumo, K., Nambu, M., and Sukuma, K. (1984). A prospective cohort study of hepatitis B surface antigen carriers in a working population. Gann 75, 571-573. Ishak, K. (1976). Light microscopic morphology of viral hepatitis. Am. J. Clin. Pathol 65, 787-827. Ishak, K. (1994). Chronic hepatitis: Morphology and nomenclature. Mod. Pathol 7, 690-713. Ishimaru, Y, Ishimaru, H., Toda, G., Baba, K., and Mayumi, M. (1976). An epidemic of infantile papular acrodermatitis (Gianotti's disease) in Japan associated with hepatitis-B surface antigen subtype ayw. Lancet i 707-709. Ito, H., Hattori, S., Matusda, I., Amamiya, S., Hajikano, H., Yoshizawa, H., Miyakawa, Y, and Mayumi, M. (1981). Hepatitis Be antigen-mediated membranous glomerulonephritis: Correlation of ultrastructural changes with HBeAg in the serum and glomeruli. Lab. Invest 44, 214-220. Johnson, P., and McFarlane, I. (1993). Meeting report. International Autoimmune Hepatitis Group. Hepatology 18, 998-1005. Johnson, R., Gretch, D., Yamabe, H., Hart, J., Bacchi, C , Hartwell, P, Couser, W, Corey, L., Wener, M., Alpers, C , and Wilson, R. (1993). Membranoproliferative glomerulonephritis associated with hepatitis C virus infection. New Engl ]. Med. 328, 465-470. Kasai, Y, Takeda, S., and Takagi, H. (1996). Pathogenesis of hepatocellular carcinoma: A review from the viewpoint of molecular analysis. Sem. Surg. Oncol 12,155-159. Kew, M., Yu, M., Kedda, M., Coppin, A., Sarkin, A., and Hodkinson, J. (1997). The relative roles of hepatitis B and C viruses in the etiology of hepatocellular carcinoma in southern African blacks. Gastroenterology 111, 184-187. Knieser, M., Jenis, E., Lowenthal, D., Bancroft, W, Bums, W, and Shalhoub, R. (1974). Pathogenesis of renal disease associated with viral hepatitis. Arch. Pathol 97,193-200. Kobayashi, S., Saigoh, K., Urashima, T, Asano, T, and Isono, K. (1997). Detection of hepatitis B virus x transcripts in human hepatocellular carcinoma tissues. /. Surg. Res. 73, 97-100. Krawczynski, K. (1993). Hepatitis E. Hepatology 17, 932-941. Krawitt, E. (1996). Autoimmune hepatitis. New Engl J. Med. 334, 897-903. Krugman, S., Ward, R., Giles, J., Bodansky, O., and Jacobs, M. (1959). Infectious hepatitis: Detection of virus during the incubation period and in clinical inapparent infection. New Engl. J. Med. 261,729-734. Kubo, S., Kinoshita, H., Hirohashi, K., Tanaka, H., Tsukamoto, T., Shuto, T, and Kuroki, T. (1997). High malignancy of hepatocellular carcinoma in alcoholic patients with hepatitis C virus. Surgery 111, 425-429. Lacour, M., and Harms, M. (1995). Gianotti-Crosti syndrome as a result of vaccination and Epstein-Barr virus infection. Eur. J. Pediatr 154, 688-689. Lai, K., Li, P, Lui, S., Au, T, Tam, J., Tong, K., and Lai, R (1991). Membranous nephropathy related to hepatitis B virus in adults. New Engl J. Med. 324,1457-1463. Lai, K., Ho, R., Tam, J., and Lai, F. (1996). Detection of hepatitis B virus DNA and RNA in kidneys of HBV related glomerulonephritis. Kidney Int 50,1965-1977. Lake, J., and Wright, T. (1991). Liver transplantation for patients with hepatitis B: What have we learned from our results? Hepatology 13, 796-799. Lee, W (1993). Acute liver failure. New Engl ]. Med. 329,1862-1872. Levey, J., Bjornsson, B., Banner, B., Kuhns, M., Malhotra, R., Whitman, N., Romain, P., Cropley, T, and Bonkovsky, H. (1994). Mixed cryoglobulinemia in chronic hepatitis C infection: A clinicopathologic analysis of 10 cases and review of recent literature. Medicine 73, 53-67.

Hepatitis Viruses Lin, H., Kao, J., Hsu, H., Ni, Y, Yeh, S., Hwang, L., Chang, M., Hwang, S., Chen, P., and Chen, D. (1994). Possible role of hightiter maternal viremia in perinatal transmission of hepatitis C virus. /. Infect Dis. 169, 638-641. Lin, H., Kao, J., Yeh, K., Liu, D., Chang, M., Chen, P, and Chen, D. (1998). Mother-to-infant transmission of GB virus C/hepatitis G virus: The role of high-titered maternal viremia and mode of delivery. /. Infect. Dis. 177,1202-1206. Linnen, J., Wages, J., Zhang-Keck, Z., Fry, K., Krawczynski, K., Alter, H., Koonin, E., Gallagher, M., Alter, M., Hadziyannis, S., Karayiannis. P., Fung, K., Nakatsuji, Y, Shih, J., Young, L., Piatak, M., Hoover, C , Fernandez,}., Chen, S., Zou, J., Morris, T., Hyams, K., Ismay, S., Lifson, J., Hess, G., Foung, S., Thomas, H., Bradley, D., Margolis, H., and Kim, J. (1996). Molecular cloning and disease association of hepatitis G virus: A transfusion-transmissible agent. Science 271, 505-508. Ljunggren, K., Patarroyo, M., Engle, R., Purcell, R., and Gerin, J. (1985). Viral hepatitis in Colombia: A study of the ''Hepatitis of the Sierra Nevada de Santa Marta.'' Hepatology 5, 299-304. Loya, F. (1996). Does the hepatitis G virus cause hepatitis? Texas Med. 92, 68-73. Lumbreras, C , Colina, F, Loinaz, C , Domingo, M., Fuertes, A., Dominguez. P., Gomez, R., Aguado, J., Lizasoain, M., Gonzalez-Pinto, I., Garcia, I., Moreno, E., and Noriega, A. (1998). Clinical, virological, and histologic evolution of hepatitis C virus infection in liver transplant recipients. Clin. Infect. Dis. 26, 48-55. Mao, J., Yu, R, Ding, Z., Chen, N., Huang, B., Xie, R., and Chai, S. (1980). Patterns of shedding of hepatitis A virus antigen in feces and of antibody responses in patients with naturally acquired type A hepatitis. /. Infect. Dis. 142, 654-659. Masuko, K., Mitsui, T, Iwano, K., Yamazaki, C , Okuda, K., Meguro, T, Murayama, N., Inoue, T, Tsuda, R, Okamoto, H., Miyakawa, Y, and Mayumi, M. (1996). Infection with hepatitis GB virus C in patients on maintenance hemodialysis. New Engl. ]. Med. 334, 1485-1490. McMahon, B., Lanier, A., Wainwright, R., and Kilkenny, J. (1990). Hepatocellular carcinoma in Alaska Eskimos: Epidemiology, clinical features and early detection. Prog. Liver Dis. 9, 643-655. Mempel, M., Abeck, D., Bye-Hansen, T, and Ring, J. (1996). GianottiCrosti syndrome in an adult patient following a recently acquired Epstein-Barr virus infection. Acta Dermato-Venereologica 76, 502503. Meyer zum Buschenfelde, K., and Lohse, A. (1995). Autoimmune hepatitis. New Engl. ]. Med. 333,1003-1005. Mondelli, M., Marms, M., and Ferrari, C. (1988). Does the immune response play a role in the pathogenesis of chronic liver disease? Arch. Pathol. Lab. Med. Ill, 489-497. Moretta, A. (1997). Molecular mechanisms in cell-mediated cytotoxicity. Cell 90,13-18. Morzycka, M., and Slusarczyk, J. (1979). Kidney glomerular pathology in various forms of acute and chronic hepatitis. Arch. Pathol. Lab. Med. 103, 38-41. Nzeako, U., Goodman, Z., and Ishak, K. (1996). Hepatocellular carcinoma and nodular regenerative hyperplasia: Possible pathogenetic relationship. Am. J. Gastroenterol 91, 879-884. Obata, H., Hayashi, N., and Motoike, Y (1980). A prospective study of development of hepatocellular carcinoma from liver cirrhosis with persistent hepatitis B virus infection. Int. J. Cancer 25, 741. Ohto, H., Terazawa, S., Sasaki, N., Sasaki, N., Hino, K., Ishiwata, C , Kako, M., Ujiie, N., Endo, C , Matsui, A., Okamoto, H., and Mishiro, S. (1994). Transmission of hepatitis C virus from mothers to infants. New Engl. ]. Med. 330, 744-750.

275

Ozawa, T, Levisohn, P., Orsini, E., and Mcintosh, R. (1976). Acute immune complex disease associated with hepatitis: Etiopathogenic and immunopathologic studies of the renal lesion. Arch. Pathol. Lab. Med. 100, 484-486. Party, I. W. (1995). Terminology of chronic hepatitis. Am. J. Gastroenterol. 90,181-189. Pawlotsky, J., Deforges, L., Bretagne, S., Andre, C , Metreau, J., Thiers, v., Zafrani, E., Goossens, M., Duval, J., Mavier, J., and Dhumeaux, D. (1993). Hepatitis C virus infection can mimic type 1 (antinuclear antibody positive) autoimmune chronic active hepatitis. Gut (Suppl.), pp. S66-S68. Peters, D., Steinberg, H., Anderson, W., Hombuckle, W., Cote, P., Gerin, J., Lewis, R., and Tennant, B. (1992). Immunopathology of glomerulonephritis associated with chronic woodchuck hepatitis virus infection in woodchucks (Marmota monax). Am. J. Pathol. 141, 143-152. Polotsky, Y, Vassell, R., and Asher, L. (1996). Immunohistochemical typing of inflammatory cells and their cytokine production in the liver of Aotus monkeys infected with hepatitis A virus. Cell Vision 3,16-20. Popper, H., Thung, S., McMahon, B., Lanier, A., Hawkins, I., and Alberts, S. (1988). Evolution of hepatocellular carcinoma associated with chronic hepatitis B virus infection in Alaskan Eskimos. Arch. Pathol. Lab. Med. 112, 498-504. Provost, P., and Hilleman, M. (1979). Propagation of human hepatitis A virus in cell culture in vitro. Proc. Soc. Exp. Biol. Med. 160, 213. Reigler, J. (1996). Preneoplastic conditions of the liver. Sem. Gastrointest. Dis. 7, 74-87. Resnick, R., and Koff, R. (1993). Hepatitis C-related hepatocellular carcinoma: Prevalence and significance. Arch. Intern. Med. 153, 1672-1677. Reyes, G. (1993). Hepatitis E virus (HEV): Molecular biology and emerging epidemiology. In ''Progress in Liver Diseases" (J. Boyer and R. Ockner, eds.). Vol. 11, pp. 203-213: W.B. Saunders, Philadelphia. Rizzetto, M., Verme, G., Recchia, S., Bonino, F, Farci, P., arico, S., Calzia, R., Picciotto, A., Colombo, M., and Popper, H. (1983). Chronic hepatitis in carriers of hepatitis B surface antigen, with intrahepatic expression of the delta antigen: An active and progressive disease unresponsive to immunosuppressive treatment. Ann. Intern. Med. 98, 437-^41. Robinson, W. (1994). Molecular events in the pathogenesis of hepadnavirus-associated hepatocellular carcinoma. Annu. Rev. Med. 45, 297-323. Saito, K., Sullivan, D., Haruna, Y, Theise, N., Thung, S., and Gerber, M. (1997). Detection of hepatitis C virus RNA sequences in hepatocellular carcinoma and its precursors by microdissection polymerase chain reaction. Arch. Pathol. Lab. Med. Ill, 400-403. San Joaquin, V., Ward, K., and Markes, M. (1981). Gianotti disease in a child and acute hepatitis B in mother. ]AMA 246, 2191-2192. Sansonno, D., Cornacchiulo, V, Racanelli, V, and Dammacco, F. (1997). In situ simultaneous detection of hepatitis C virus RNA and hepatitis C virus-related antigens in hepatocellular carcinoma. Cancer 80, 22-23. Schulte-Hermann, R., Bursch, W., and Grasl-Kraupp, B. (1995). Active cell death (apoptosis) in liver biology and disease. Prog. Liver Dis. 13,1-35. Shimoda, T., Uchida, T, Miyata, H., Abe, K., Ariga, H., Shikata, T, and Fujii, Y (1980). A 6-year-old boy having hepatocellular carcinoma associated with hepatitis B surface antigenemia. Am. ]. Clin. Pathol. 74, 827-831.

276

Pathology and Pathogenesis of Human Viral D i s e a s e

Shiratori, Y, Shiina, S., Imamura, M., Kato, N., Kanai, R, Okudaira, T., Teratani, T., Tohgo, G., Toda, N., M, O., et al. (1995). Characteristic difference of hepatocellular carcinoma between hepatitis B- and C" viral infection in Japan. Hepatology 22 (4, Pt. 1), 10271033. Silini, E., Bottelli, R., Asti, M., Bruno, S., Candusso, M., Brambilla, S., Bono, R, lamoni, G., Tinelli, C., Mondelli, M., and Ideo, G. (1996). Hepatitis C virus genotypes and risk of hepatocellular carcinoma in cirrhosis: a case-control study. Gasterenterology 111, 199-205. Smedile, A., Farci, R, Verme, G., et al (1982). Influence of delta infection on severity of hepatitis B. Lancet 1, 945-947. Southwest Pediatric Nephrology Group (Dallas) (1985). Hepatitis B surface antigenemia in North American children with membranous glomerulonephropathy. /. Pediatr. 106, 571-578. Stark, K., Bienzle, U., Hess, G., Engel, A., Hegenscheid, B., and Schluter, V. (1996). Detection of the hepatitis G virus genome among injecting drug users, homosexual and bisexual men, and blood donors. /. Infect. Dis. 174,1320-1323. Stromeyer, R, Ishak, K., Gerber, M., and Mathew, T. (1980). Groundglass cells in hepatocellular carcinoma. Am. J. Clin. Pathol. 74, 254-258. Tanaka, T., Miyamoto, H., Hino, O., Kitagawa, T., Koike, M., lizuka, T., Sakamoto, H., and Ooshima, A. (1986). Primary hepatocellular carcinoma with hepatitis B virus-DNA integration in a 4-year old boy. Hum. Pathol. 17, 202-204. Tanaka, K., Ikematsu, H., Hirohata, T., and Kashiwagi, S. (1996). Hepatitis C virus infection and risk of hepatocellular carcinoma among Japanese: Possible role of type lb (II) infection. /. Natl. Cancer Inst. 88, 742-746. Tang, L., Tanaka, Y, Enomoto, N., Marumo, R, and Sato, C. (1995). Detectionof hepatitis C virus RNA in hepatocellular carcinoma by in situ hybridization. Cancer 76, 2211-2216. Thomas, D., Nakatsuji, Y, Shih, J., Alter, H., Nelson, K., Astemborski, J., Lyles, C., and Vlahov, D. (1997). Persistence and clinical significance of hepatitis G virus infections in injecting drug users. /. Infect. Dis. 176, 586-592. Thornton, A., Zuckerman, A., and Almeida, J. (1975). Chimpanzee model for hepatitis-A virus [letter]. Lancet 2, 226.

Toda, G., Ishimaru, Y, Mayumi, M., and Oda, T (1978). Infantile papular acrodermatitis (Gianotti's disease) and intrafamilial occurrence of acute hepatitis B with jaundice: Age dependency of clinical manifestations of hepatitis B virus infection. /. Infect. Dis. 138, 211-216. Tovo, P., Palomba, E., Ferraris, G., Principi, N., Ruga, E., Dallacasa, P., and Maccabruni, A. (1997). Increased risk of maternal-infant hepatitis C virus transmission for women coinfected with human immunodeficiency virus type 1. Clin. Infect. Dis. 25,1121-1124. Tsukuma, H., Hiyama, T, Tanaka, S., Nakao, M., Yabuuchi, T, Kitamura, T., Nakanishi, K., Fujimoto, I., Inoue, A., Yamazaki, H., and Kawashima, T. (1993). Risk factors for hepatocellular carcinoma among patients with chronic liver disease. New Engl. J. Med. 328, 1797-1801. Tzeng, G., Hsu, C , and Chen, H. (1995). Gianotti-Crosti syndrome associated with cytomegalovirus infection: Report of one case. Chung-Hua Min Kuo Hsiao Erh Ko i Hsueh Hui Tsa Chih 36,139-141. Vallbracht, A., Maier, K., Stierhof, Y, Wiedmann, K., Flehmig, B., and Fleischer, B. (1989). Liver-derived cytotoxic T cells in hepatitis A virus infection. /. Infect. Dis. 160, 209-217. Venkataseshan, V., Lieberman, K., Kim, D., Thung, S., Dikman, S., D'Agati, v., Susin, M., Valderrama, E., Gauthier, B., Prakash, A., and Churg, J. (1990). Hepatitis-B-associated glomerulonephritis: pathology, pathogenesis, and clinical course. Medicine 69,200-216. Verme, G., Amoroso, P., Lettieri, G., Pierri, P., David, E., Sessa, R, Rizzi, R., Bonino, R, Recchia, S., and Rizzetto, M. (1986). A histological study of hepatitis delta virus liver disease. Hepatology 6, 1303-1307. Wang, K., Choo, Q., Weiner, A., Ou, J., Najarian, R., Thayer, R., MuUenbach, G., Denniston, K., Gerin, J., and Houghton, M. (1986). Structure, sequence and expression of the hepatitis delta viral genome. Nature 323, 508. Yeh, R, Yu, M., Mo, C , et al. (1989). Hepatitis B virus, aflatoxins, and hepatocellular carcinoma in southern Guangxi, China. Cancer Res. 49, 2506-2509. Zein, N., Poterucha, J., Gross Jr., J., Wiesner, R., Therneau, T, Gossard, A., Wendt, N., Mitchell, P, Germer, J., and Persing, D. (1996). Increased risk of hepatocellular carcinoma in patients infected with hepatitis C genotype lb. Am. J. Gastroenterol. 91, 2560-2562.