- Email: [email protected]
A marker for hepatocellular damage
CORRESPONDENCE
have not included our sequences in their analyses, although the sequences were already available in the GenBank database at the time when they prepared their manuscript. BDV has been seen as genetically invariable and to form a single type. Consequently, all assays for the diagnosis of BDV are based on this single type. However, as we have shown,3 other subtypes may exist and most of the standard reverse transcriptase-PCR protocols used to date for the diagnosis of human and animal BDV would fail to detect such a novel strain. This work was supported by a grant of the Austrian Federal State of Vorarlberg.
*Norbert Nowotny, Jolanta Kolodziejek Institute of Virology, University of Veterinary Sciences, A-1210 Vienna, Austria (e-mail: [email protected]) 1
2
3
Schwemmle M, Jehle C, Formella S, Staeheli P. Sequence similarities between human bornavirus isolates and laboratory strains question human origin. Lancet 1999; 354: 1973–74. Nowotny N, Kolodziejek J. Demonstration of Borna disease virus nucleic acid in a patient suffering from chronic fatigue syndrome. J Infect Dis 2000 (in press). Nowotny N, Kolodziejek J, Jehle C, Suchy A, Staeheli P, Schwemmle M. Isolation and characterisation of a new subtype of Borna disease virus. J Virol 2000 (in press).
from human beings were reported to be highly susceptible to amantadine,1 whereas laboratory strains are not.2,3 Furthermore, the isolates from human beings seem to exhibit reduced pathology in deliberately infected rats.4 Since the BDV isolates from human beings were not made available to the research community, verification of these differences by independent laboratories has to date not been possible. To achieve an agreement between the various laboratories on the highly controversial question of whether human bornaviruses do exist, multicentre studies should be organised in which pre-PCR handling of samples is done by a neutral laboratory with no history of experimental or diagnostic work on BDV, and in which multiple samples of the various specimens are stored for independent testing by several bornavirus laboratories. *Peter Staeheli, Martin Schwemmle Abteilung Virologie, Institut für Medizinische, Mikrobiologie und Hygiene, Universität Freiburg, D-79104 Freiburg, Germany (e-mail: [email protected]) 1
2
Authors’ reply Sir—By searching databases and published reports on borna disease virus (BDV) we identified 36 sequences of N (p40) gene fragments believed to originate from viruses present in tissue or blood of 18 different patients, and an even higher number of P (p24) gene sequences. To keep the figure in our paper as simple as possible we did not include all this information in the phylogenetic tree. Most of the ignored sequences matched the familiar pattern that we described: they showed the highest degree of similarity to BDV strains frequently used for laboratory work by the reporting laboratories. A few other sequences, including those of Berlin patient III, and the Austrian patients with chronic fatigue syndrome, did not easily fit this picture. We agree with our colleagues that our sequence comparison does not rule out a human origin of these exceptional viruses. However, we do not agree with the view that lack of strong similarity to laboratory strains is solid proof of a human origin of these viruses. Liv Bode and co-workers argue that biological differences between BDV strains from animals and human beings would exclude the contamination hypothesis. Indeed, the isolates
THE LANCET • Vol 355 • April 22, 2000
3
4
Bode L, Dietrich DF, Stoyloff R, Emrich HM, Ludwig H. Amantadine and human Borna disease virus in vitro and in vivo in an infected patient with bipolar depression. Lancet 1997; 349: 178–79. Hallensleben W, Zocher M, Staeheli P. Borna disease virus is not sensitive to amantadine. Arch Virol 1997; 142: 2043–48. Cubitt B, de la Torre JC. Amantadine does not have antiviral activity against Borna disease virus. Arch Virol 1997; 142: 2035–42. Bode L, Dürrwald R, Rantam FA, Ferszi R, Ludwig L. First isolates of infectious human Borna disease virus from patients with mood disorders. Mol Psychiatry 1996; 1: 200–12.
A marker for hepatocellular damage Sir—In his Feb 19 commentary 1 Michael C Kew outlines the pros and cons of measurement of serum aminotransferase activity in the detection of hepatocellular damage. Glutathione S-transferase alpha 1-1 (GSTA1-1) is a relatively new marker for hepatocellular impairment, which has proven its benefits when compared with aminotransferase measurements. 2,3 Aminotransferase activities do not accurately reflect the severity of the underlying histopathological condition in acute hepatic impairment. Aspartate aminotransferase (AST) is found in high concentrations in heart and skeletal muscle, kidney, pancreas, and erythrocytes, making it an unspecific marker, especially in conditions in which haemolysis is involved. The
more liver-specific alanine aminotransferase (ALT) has a relatively long half-life (47 h), which makes detection of acute liver impairment unreliable. Furthermore, the aminotransferases are periportally located, which results in a limited leakage due to toxic or hypoxic hepatocellular damage.2 GSTA1-1 concentration in blood is a more specific marker. GSTA1-1 is rapidly released in relatively large amounts into the blood stream after acute hepatocellular damage. Because of the short plasma half life (<1 h) its concentration will follow changes in acute hepatocellular damage more accurately than those of AST (half-life 17 h) and ALT. Glutathione Stransferases (GSTs) are detoxification enzymes that catalyse the addition of glutathione to various xenobiotics. Cytosolic GSTs are dimeric proteins and are divided into five main classes: alpha, mu, pi, theta, and zeta. About 2% of the soluble protein in the liver consists of class ␣ GST. In contrast to the periportal location of the aminotransferases, glutathione Stransferase ␣ is primarily located in centrilobular hepatocytes. The sensitivity and specificity of GSTA1-1 has been tested in various conditions of acute hepatocellular impairment, such as acute viral, toxic, and drug induced (eg, acetaminophen) hepatitis and hypoxia-induced liver failure (eg, neonatal asphyxia). In all of these studies GSTA1-1 more accurately followed the temporal pattern of liver impairment and recovery, and the relative magnitude of elevation of GSTA1-1 concentrations was significantly higher than that of the aminotransferases. We investigated the significance of plasma GSTA1-1 measurements in hypertensive disorders of pregnancy, in particular the haemolysis-elevated liver enzymes and low platelets syndrome, which are characterised by multiple-organ impairment, especially of the liver and erythrocytes. The deterioration of hepatic function is a crucial determinant in the management of these syndromes. Plasma concentrations of GSTA1-1 mapped periods of epigastric pain, presumably due to liver infarctions, more accurately than ALT; the elevation of GSTA1-1 concentrations preceded those of ALT by several hours, whereas the relative magnitude of elevation was significantly higher (up to 500 times) than that of ALT.4,5 In the recovery phase, in contrast to ALT concentrations, concentrations of GSTA1-1 rapidly declined. Since GSTA1-1 is not present in erythrocytes, the concomitant
1463
CORRESPONDENCE
Maarten F C M Knapen, Wilbert H M Peters, Theo P J Mulder, *Eric A P Steegers Departments of *Obstetrics and Gynaecology and Gastroenterology, University Hospital Nijmegen, PO Box 9101, 6500 HB Nijmegen, Netherlands (e-mail: [email protected]) 1
2
3
4
5
Kew MC. Serum aminotransferase concentration as evidence of hepatocellular damage. Lancet 2000; 355: 591–92. Beckett GJ, Hayes JD. Glutathione S-transferases: biomedical applications. Adv Clin Chem 1993; 30: 281–380. Rees GW, Trull AK, Doyle S. Evaluation of an enzyme-immunometric assay for serum ␣-glutathione Stransferase. Ann Clin Biochem 1995; 32: 575–83. Steegers EAP, Mulder TPJ, Bisseling JGA, Delemarre FMC, Peters WHM. Glutathione S-transferase alpha as marker for hepatocellular damage in pre-eclampsia and HELLP syndrome. Lancet 1995; 345: 1571–72. Knapen MFCM, Mulder TPJ, Bisseling JGA, Penders RHMJ, Peters WHM, Steegers EAP. Plasma glutathione S-transferase Alpha 1-1: a more sensitive marker for hepatocellular impairment than serum alanine aminotransferase in hypertensive disorders of pregnancy. Am J Obstet Gynecol 1998; 178: 161–65.
Hepatitis B booster vaccination for healthcare workers Sir—The European Consensus Group on Hepatitis B Immunity (Feb 12, p 561)1 said that boosters are not needed for healthcare workers and others at occupational risk of infection, in whom adequate immunological priming has been achieved, even if antibody titres to hepatitis B surface antigen (HBsAg) decline after vaccination. Zuckerman and colleagues2 also recommended testing for antibodies to HBsAg 1 month after the primary vaccination or booster to ensure protection against hepatitis B virus (HBV) infection and disease, and emphasised the reliance on immunological memory rather than booster doses to protect against infection.
1464
1 Positivity probability
haemolysis does not influence GSTA1-1 concentrations, as is the case for AST activity measurements. In pre-eclampsia, measurements of both ALT and GSTA1-1 concentrations showed evidence of hepatocellular impairment more frequently than when ALT alone was measured.5 In acute liver impairment GSTA1-1 measurements should be considered more often, to allow reliable clinical assessment.
⬍26 years
0·8 0·6
⭓26 years
0·4 0·2 0
p⬍0·001 (by the log-rank test)
0
5
0
30
5
10
Days
15
20
25
30
Months Time after the vaccination
Life-table of the titre of HBV antibody in healthcare workers according to age
We analysed, with a life-table method, the immune response in 526 healthcare workers whose anti-HBsAg titre rose to over 100 mIU/mL 1 month after the immunisation (figure). After the booster vaccination, anti-HBV titres did not rise significantly within 7 days and had fallen below 100 mIU/mL (assumed to be the protective antibody concentration) in 56% of those vaccinated 28 months after the vaccination. The persistence of antibodies to HBsAg was closely associated with the peak response and age of the individual. Jilg and colleagues3 reported poor response to HB vaccination in groups of older individuals. The existence of an immunological memory even in people with measurable antibodies a month after revaccination did not make it possible to re-establish protective immunity with a week, which is of importance for previously vaccinated people with decreased antibody concentrations, who are exposed to HBV—eg, after a needle stick injury. In the study by Zanetti and colleagues4 antibody a, which is generally regarded as the protective antibody against HBV, was not detected for a few weeks after immunisation and infection. Furthermore, it is suggested that combined prophylaxis with HB immunoglobulins and vaccine should result in a substantial risk of infection because of the variable response and delay in the development of antibody a after active immunisation in some people. Hadler reported that and colleagues5 protection against HB infection parallels the persistence of antibodies to HBsAg and that lower responders developed HBsAg-positive infection. Healthcare workers and others at occupational risk of HBV infection in Japan, are advised to be vaccinated against HBV and to get regular boosters to maintain seropositivity
for HBsAg antibodies. Passive immunisation with HB immunoglobulins has been considered for people with decreased antibody concentrations, who have had accidental exposure. But this type of immunisation is 20 times more expensive than booster vaccination. Our findings suggest that booster vaccinations are the best way to maintain long-term immunity, at least in low responders (below 100 mIU/mL) and elderly healthcare workers. Risk of HBV transmission through occupational exposure in healthcare workers is about 27–43% from a percutaneous injury from an HBsAgpositive needle or instrument. The necessity of the booster and the exact timing of such boosters is still matter of debate. Cost-benefit evaluation and prevention of infection and transmission to patients in high-risk groups must be considered. We suggest that all individuals with HBsAg antibody concentrations below 100 mIU/mL, should have a booster every 2 years and their response should be monitored 4 weeks after the booster. *Tadashi Yoshida, Ikuo Saito Health Center, School of Medicine, Keio University, Tokyo 160-8582, Japan (e-mail: [email protected]) 1
2
3
4
5
European consensus group on hepatitis B immunity. Are booster immunisations needed for lifelong hepatitis B immunity? Lancet 2000; 355: 561–65. Zuckerman JN, Zuckerman AJ. Is there a need for boosters of hepatitis B vaccine? Viral Hepatitis Rev 1998; 4: 43–46. Jilg W, Schmidt M, Deinhardt F. Immune response to hepatitis B revaccination. J Med Virol 1988; 24: 377–84. Zanetti AR, Tanzi E. Romano L, et al. Kinetics of antibody response to hepatitis B virus determinants and to recombinant vaccines in Italy. J Med Virol 1990; 32: 219–24. Hadler SC, Francis DP, Maynard JE, et al. Long-term immunogenicity and efficacy of hepatitis B vaccine in homosexual men. N Engl J Med 1986; 315: 209–14.
THE LANCET • Vol 355 • April 22, 2000
have not included our sequences in their analyses, although the sequences were already available in the GenBank database at the time when they prepared their manuscript. BDV has been seen as genetically invariable and to form a single type. Consequently, all assays for the diagnosis of BDV are based on this single type. However, as we have shown,3 other subtypes may exist and most of the standard reverse transcriptase-PCR protocols used to date for the diagnosis of human and animal BDV would fail to detect such a novel strain. This work was supported by a grant of the Austrian Federal State of Vorarlberg.
*Norbert Nowotny, Jolanta Kolodziejek Institute of Virology, University of Veterinary Sciences, A-1210 Vienna, Austria (e-mail: [email protected]) 1
2
3
Schwemmle M, Jehle C, Formella S, Staeheli P. Sequence similarities between human bornavirus isolates and laboratory strains question human origin. Lancet 1999; 354: 1973–74. Nowotny N, Kolodziejek J. Demonstration of Borna disease virus nucleic acid in a patient suffering from chronic fatigue syndrome. J Infect Dis 2000 (in press). Nowotny N, Kolodziejek J, Jehle C, Suchy A, Staeheli P, Schwemmle M. Isolation and characterisation of a new subtype of Borna disease virus. J Virol 2000 (in press).
from human beings were reported to be highly susceptible to amantadine,1 whereas laboratory strains are not.2,3 Furthermore, the isolates from human beings seem to exhibit reduced pathology in deliberately infected rats.4 Since the BDV isolates from human beings were not made available to the research community, verification of these differences by independent laboratories has to date not been possible. To achieve an agreement between the various laboratories on the highly controversial question of whether human bornaviruses do exist, multicentre studies should be organised in which pre-PCR handling of samples is done by a neutral laboratory with no history of experimental or diagnostic work on BDV, and in which multiple samples of the various specimens are stored for independent testing by several bornavirus laboratories. *Peter Staeheli, Martin Schwemmle Abteilung Virologie, Institut für Medizinische, Mikrobiologie und Hygiene, Universität Freiburg, D-79104 Freiburg, Germany (e-mail: [email protected]) 1
2
Authors’ reply Sir—By searching databases and published reports on borna disease virus (BDV) we identified 36 sequences of N (p40) gene fragments believed to originate from viruses present in tissue or blood of 18 different patients, and an even higher number of P (p24) gene sequences. To keep the figure in our paper as simple as possible we did not include all this information in the phylogenetic tree. Most of the ignored sequences matched the familiar pattern that we described: they showed the highest degree of similarity to BDV strains frequently used for laboratory work by the reporting laboratories. A few other sequences, including those of Berlin patient III, and the Austrian patients with chronic fatigue syndrome, did not easily fit this picture. We agree with our colleagues that our sequence comparison does not rule out a human origin of these exceptional viruses. However, we do not agree with the view that lack of strong similarity to laboratory strains is solid proof of a human origin of these viruses. Liv Bode and co-workers argue that biological differences between BDV strains from animals and human beings would exclude the contamination hypothesis. Indeed, the isolates
THE LANCET • Vol 355 • April 22, 2000
3
4
Bode L, Dietrich DF, Stoyloff R, Emrich HM, Ludwig H. Amantadine and human Borna disease virus in vitro and in vivo in an infected patient with bipolar depression. Lancet 1997; 349: 178–79. Hallensleben W, Zocher M, Staeheli P. Borna disease virus is not sensitive to amantadine. Arch Virol 1997; 142: 2043–48. Cubitt B, de la Torre JC. Amantadine does not have antiviral activity against Borna disease virus. Arch Virol 1997; 142: 2035–42. Bode L, Dürrwald R, Rantam FA, Ferszi R, Ludwig L. First isolates of infectious human Borna disease virus from patients with mood disorders. Mol Psychiatry 1996; 1: 200–12.
A marker for hepatocellular damage Sir—In his Feb 19 commentary 1 Michael C Kew outlines the pros and cons of measurement of serum aminotransferase activity in the detection of hepatocellular damage. Glutathione S-transferase alpha 1-1 (GSTA1-1) is a relatively new marker for hepatocellular impairment, which has proven its benefits when compared with aminotransferase measurements. 2,3 Aminotransferase activities do not accurately reflect the severity of the underlying histopathological condition in acute hepatic impairment. Aspartate aminotransferase (AST) is found in high concentrations in heart and skeletal muscle, kidney, pancreas, and erythrocytes, making it an unspecific marker, especially in conditions in which haemolysis is involved. The
more liver-specific alanine aminotransferase (ALT) has a relatively long half-life (47 h), which makes detection of acute liver impairment unreliable. Furthermore, the aminotransferases are periportally located, which results in a limited leakage due to toxic or hypoxic hepatocellular damage.2 GSTA1-1 concentration in blood is a more specific marker. GSTA1-1 is rapidly released in relatively large amounts into the blood stream after acute hepatocellular damage. Because of the short plasma half life (<1 h) its concentration will follow changes in acute hepatocellular damage more accurately than those of AST (half-life 17 h) and ALT. Glutathione Stransferases (GSTs) are detoxification enzymes that catalyse the addition of glutathione to various xenobiotics. Cytosolic GSTs are dimeric proteins and are divided into five main classes: alpha, mu, pi, theta, and zeta. About 2% of the soluble protein in the liver consists of class ␣ GST. In contrast to the periportal location of the aminotransferases, glutathione Stransferase ␣ is primarily located in centrilobular hepatocytes. The sensitivity and specificity of GSTA1-1 has been tested in various conditions of acute hepatocellular impairment, such as acute viral, toxic, and drug induced (eg, acetaminophen) hepatitis and hypoxia-induced liver failure (eg, neonatal asphyxia). In all of these studies GSTA1-1 more accurately followed the temporal pattern of liver impairment and recovery, and the relative magnitude of elevation of GSTA1-1 concentrations was significantly higher than that of the aminotransferases. We investigated the significance of plasma GSTA1-1 measurements in hypertensive disorders of pregnancy, in particular the haemolysis-elevated liver enzymes and low platelets syndrome, which are characterised by multiple-organ impairment, especially of the liver and erythrocytes. The deterioration of hepatic function is a crucial determinant in the management of these syndromes. Plasma concentrations of GSTA1-1 mapped periods of epigastric pain, presumably due to liver infarctions, more accurately than ALT; the elevation of GSTA1-1 concentrations preceded those of ALT by several hours, whereas the relative magnitude of elevation was significantly higher (up to 500 times) than that of ALT.4,5 In the recovery phase, in contrast to ALT concentrations, concentrations of GSTA1-1 rapidly declined. Since GSTA1-1 is not present in erythrocytes, the concomitant
1463
CORRESPONDENCE
Maarten F C M Knapen, Wilbert H M Peters, Theo P J Mulder, *Eric A P Steegers Departments of *Obstetrics and Gynaecology and Gastroenterology, University Hospital Nijmegen, PO Box 9101, 6500 HB Nijmegen, Netherlands (e-mail: [email protected]) 1
2
3
4
5
Kew MC. Serum aminotransferase concentration as evidence of hepatocellular damage. Lancet 2000; 355: 591–92. Beckett GJ, Hayes JD. Glutathione S-transferases: biomedical applications. Adv Clin Chem 1993; 30: 281–380. Rees GW, Trull AK, Doyle S. Evaluation of an enzyme-immunometric assay for serum ␣-glutathione Stransferase. Ann Clin Biochem 1995; 32: 575–83. Steegers EAP, Mulder TPJ, Bisseling JGA, Delemarre FMC, Peters WHM. Glutathione S-transferase alpha as marker for hepatocellular damage in pre-eclampsia and HELLP syndrome. Lancet 1995; 345: 1571–72. Knapen MFCM, Mulder TPJ, Bisseling JGA, Penders RHMJ, Peters WHM, Steegers EAP. Plasma glutathione S-transferase Alpha 1-1: a more sensitive marker for hepatocellular impairment than serum alanine aminotransferase in hypertensive disorders of pregnancy. Am J Obstet Gynecol 1998; 178: 161–65.
Hepatitis B booster vaccination for healthcare workers Sir—The European Consensus Group on Hepatitis B Immunity (Feb 12, p 561)1 said that boosters are not needed for healthcare workers and others at occupational risk of infection, in whom adequate immunological priming has been achieved, even if antibody titres to hepatitis B surface antigen (HBsAg) decline after vaccination. Zuckerman and colleagues2 also recommended testing for antibodies to HBsAg 1 month after the primary vaccination or booster to ensure protection against hepatitis B virus (HBV) infection and disease, and emphasised the reliance on immunological memory rather than booster doses to protect against infection.
1464
1 Positivity probability
haemolysis does not influence GSTA1-1 concentrations, as is the case for AST activity measurements. In pre-eclampsia, measurements of both ALT and GSTA1-1 concentrations showed evidence of hepatocellular impairment more frequently than when ALT alone was measured.5 In acute liver impairment GSTA1-1 measurements should be considered more often, to allow reliable clinical assessment.
⬍26 years
0·8 0·6
⭓26 years
0·4 0·2 0
p⬍0·001 (by the log-rank test)
0
5
0
30
5
10
Days
15
20
25
30
Months Time after the vaccination
Life-table of the titre of HBV antibody in healthcare workers according to age
We analysed, with a life-table method, the immune response in 526 healthcare workers whose anti-HBsAg titre rose to over 100 mIU/mL 1 month after the immunisation (figure). After the booster vaccination, anti-HBV titres did not rise significantly within 7 days and had fallen below 100 mIU/mL (assumed to be the protective antibody concentration) in 56% of those vaccinated 28 months after the vaccination. The persistence of antibodies to HBsAg was closely associated with the peak response and age of the individual. Jilg and colleagues3 reported poor response to HB vaccination in groups of older individuals. The existence of an immunological memory even in people with measurable antibodies a month after revaccination did not make it possible to re-establish protective immunity with a week, which is of importance for previously vaccinated people with decreased antibody concentrations, who are exposed to HBV—eg, after a needle stick injury. In the study by Zanetti and colleagues4 antibody a, which is generally regarded as the protective antibody against HBV, was not detected for a few weeks after immunisation and infection. Furthermore, it is suggested that combined prophylaxis with HB immunoglobulins and vaccine should result in a substantial risk of infection because of the variable response and delay in the development of antibody a after active immunisation in some people. Hadler reported that and colleagues5 protection against HB infection parallels the persistence of antibodies to HBsAg and that lower responders developed HBsAg-positive infection. Healthcare workers and others at occupational risk of HBV infection in Japan, are advised to be vaccinated against HBV and to get regular boosters to maintain seropositivity
for HBsAg antibodies. Passive immunisation with HB immunoglobulins has been considered for people with decreased antibody concentrations, who have had accidental exposure. But this type of immunisation is 20 times more expensive than booster vaccination. Our findings suggest that booster vaccinations are the best way to maintain long-term immunity, at least in low responders (below 100 mIU/mL) and elderly healthcare workers. Risk of HBV transmission through occupational exposure in healthcare workers is about 27–43% from a percutaneous injury from an HBsAgpositive needle or instrument. The necessity of the booster and the exact timing of such boosters is still matter of debate. Cost-benefit evaluation and prevention of infection and transmission to patients in high-risk groups must be considered. We suggest that all individuals with HBsAg antibody concentrations below 100 mIU/mL, should have a booster every 2 years and their response should be monitored 4 weeks after the booster. *Tadashi Yoshida, Ikuo Saito Health Center, School of Medicine, Keio University, Tokyo 160-8582, Japan (e-mail: [email protected]) 1
2
3
4
5
European consensus group on hepatitis B immunity. Are booster immunisations needed for lifelong hepatitis B immunity? Lancet 2000; 355: 561–65. Zuckerman JN, Zuckerman AJ. Is there a need for boosters of hepatitis B vaccine? Viral Hepatitis Rev 1998; 4: 43–46. Jilg W, Schmidt M, Deinhardt F. Immune response to hepatitis B revaccination. J Med Virol 1988; 24: 377–84. Zanetti AR, Tanzi E. Romano L, et al. Kinetics of antibody response to hepatitis B virus determinants and to recombinant vaccines in Italy. J Med Virol 1990; 32: 219–24. Hadler SC, Francis DP, Maynard JE, et al. Long-term immunogenicity and efficacy of hepatitis B vaccine in homosexual men. N Engl J Med 1986; 315: 209–14.
THE LANCET • Vol 355 • April 22, 2000