- Email: [email protected]
Findings and conclusions from CMV hyperimmune globulin treatment trials
Journal of Clinical Virology 46S (2009) S54–S57
Contents lists available at ScienceDirect
Journal of Clinical Virology journal homepage: www.elsevier.com/locate/jcv
Findings and conclusions from CMV hyperimmune globulin treatment trials Stuart P. Adler a,∗ , Giovanni Nigro b a b
Department of Pediatrics, Virginia Commonwealth University, Medical College of Virginia Campus, Box 163, Richmond, VA 23298, United States Department of Pediatrics, University of L’Aquila, L’Aquila, Italy
a r t i c l e
i n f o
Article history: Received 31 March 2009 Received in revised form 25 August 2009 Accepted 29 August 2009 Keywords: Cytomegalovirus Passive immunization Hyperimmune globulin Pregnancy Congenital CMV infection CMV antibodies CMV immunity
a b s t r a c t A primary maternal infection with cytomegalovirus (CMV) either during or just before pregnancy accounts for the majority of congenital infections where the baby is symptomatic at birth. Following a primary maternal infection, depending on gestational age, between one quarter and three quarters of fetuses will become infected, and approximately one-third of infected fetuses will have symptoms at birth. Experiments using animal models of CMV infection and observational studies in humans indicate that administration of a CMV hyperimmune globulin (HIG) to the pregnant woman with a primary CMV infection should be effective for both the treatment and prevention of fetal infection. The HIG probably acts by reducing placental inflammation, neutralizing virus with high avidity antibodies, and perhaps by reducing cytokine mediated cellular immune responses. © 2009 Elsevier B.V. All rights reserved.
1. Introduction In 1999, a United States Institute of Medicine report called “Vaccines for the 21st Century” identified the need for a vaccine for women of childbearing age to protect against CMV as a high priority for new vaccines.1 This was based on cost effectiveness and improvement in the quality of life a vaccine would afford affected children. Pending the availability of an active vaccine, recent animal and human studies indicate that fetal CMV disease after a primary maternal infection during pregnancy may be reversed or modified by passive immunization with high avidity neutralizing antibodies directed against CMV. This article will review the evidence indicating that passive immunization should be highly effective for preventing or treating CMV infections of the fetus among women with a primary CMV infection during pregnancy. 2. Immunoglobulin availability One reason to consider passive immunization for treating or preventing CMV infections of the fetus is that appropriate immunoglobulin preparations are available. Currently, worldwide there are three available sources of intravenous immunoglobulin enriched for antibodies against CMV. In the US the available CMV hyperimmune globulin is Cytogam (CSL Behring) and in Europe the product is Cyotect (Biotest AG). The Australian Red Cross blood
services also produce an intravenous immunoglobulin preparation enriched for antibodies to CMV. We have tested the neutralizing activity of each preparation by measuring the titer of antibodies directed against CMV glycoprotein B, a CMV envelope protein, which induces the majority of neutralizing activity directed against CMV and against viral entry into endothelial cells. Each product has an anti-gB titer of 1/400,000. This is approximately 2–4-fold higher than that observed among individuals naturally seropositive for CMV. Cytogam and Cytotect also contain very high titers of antibodies that block viral entry into endothelial and epithelial cells.2 Regarding safety, intravenous immunoglobulins are the most purified among the blood derivatives, including albumin, and are the only derivatives which can be pasteurized. Intravenous immunoglobulins are used each year to safely treat many tens of thousands of patients such as transplant patients and those with Kawasaki’s disease, immune deficiencies, thrombocyptopenia, etc. Immunoglobulin has been used safely in pregnancy for decades,3 primarily to treat blood group incompatibilities but also for passive immunization against rubella, hepatitis A and B, varicella, and measles. A few batches of intramuscularly (not intravenous) administered immunoglobulin were contaminated with hepatitis C in the late 1970s. For intravenous immunoglobulins, in over 17 years of use, no case of viral transmission has been reported.4,5 3. Animal models
∗ Corresponding author. E-mail address: [email protected] (S.P. Adler). 1386-6532/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.jcv.2009.08.017
Another reason to consider passive immunization for treating or preventing CMV infections of the fetus, is based on
S.P. Adler, G. Nigro / Journal of Clinical Virology 46S (2009) S54–S57 Table 1 Summary of passive immunization studies using the guinea pig model. Reference
Immune serum to
Controls
Treatment group
Number of pups surviving/number observed (%)
Number of pups surviving/number observed (%) 34/42 (81)a 33/46 (77)b 20/23 (87) 18/25 (72)
7
Whole virus
23/45 (51)
8 9
Guinea pig gB Whole virus
2/12 (17) 13/26 (50)
a b
Immune serum administered after viral challenge of the pregnant dame. Immune serum administered before viral challenge of the pregnant dame.
the effectiveness observed in animal models. The guinea pig model of cytomegalovirus (GPCMV) infection is useful because GPCMV crosses the guinea pig placenta, causing infection in utero and the structure of the guinea pig placenta is similar to the human placenta.6 In the guinea pig model fetal infection leads to fetal death, so pup survival is the endpoint used in guinea pig experiments.6 Thus, the guinea pig model has been used frequently to study the role of antibodies induced by either active or passive immunization to interrupt intrauterine transmission and/or protect the fetus. The guinea pig model has evaluated passive immunization for protective effects on the fetus.7–9 In these studies pregnant guinea pigs were challenged with guinea pig (gp) CMV before or after passive administration of neutralizing anti-sera to either whole virus or gB, a glycoprotein that induces neutralizing antibodies.7–9 In two separate reports passive administration of immune serum to whole virus significantly increased fetal survival (Table 1) even though it did not affect the rate of fetal infection, indicating that the immune serum was therapeutic. In other guinea pig experiments with immune sera to purified gB, there was reduced fetal infection, placental inflammation, fetal death, and enhanced fetal growth.9 In these experiments fetal survival was enhanced for dames treated with immune globulin to gpCMV gB compared with controls (Table 1). This effect was independent of whether immune globulin was administered before or after the challenge virus.9 Additional high-titer immune globulin given before or after maternal challenge significantly reduced the rate of fetal infection from 39% (9 of 23 fetuses infected) to 0% (0 of 18 fetuses infected).9 Immune globulin to gB, administered before or after maternal challenge, also significantly reduced placental inflammation and enhanced fetal growth, as measured by fetal weight. In the guinea pig model, there are several plausible mechanisms for the therapeutic efficacy of passive immunization: immunomodulatory effects, reduction of maternal viremia and viral load, and/or decreased placental inflammation resulting in increased blood flow with enhanced fetal nutrition, oxygenation, and survival. The brains of a high proportion of human fetuses infected with CMV in utero after a primary maternal infection contain CMV and an associated inflammatory response.10 Therefore it is of interest to note a recent study of passive immunization that used a mouse model.11 Mouse CMV does not cross the mouse placenta, so mouse CMV was injected into the peritoneal cavity of newborn mice.11 This led to viral infection of the brains of the infant mice with associated inflammatory lesions in the brains. These lesions consisted of mononuclear cell infiltrations and prominent glial nodules. Treatment of the newborn mice with either immune sera or monoclonal antibodies directed against the mouse CMV gB resulted in markedly reduced amounts of virus in the brains as well as over 5-fold reductions in inflammatory lesions in the brain. These observations suggested that antiviral antibodies limited both viral replication in the brain and viral induced brain damage.
S55
4. Maternal immunity antibodies suggests a role for CMV-specific maternal antibodies A mother’s first infection with CMV during pregnancy causes the majority of congenital infections where the baby has neurosensory hearing deficit and/or mental retardation.12,13 If a first maternal CMV infection occurs in the first trimester, approximately 25% of fetuses will be infected; in the second trimester approximately 50%; in the third approximately 75% will be infected.14 Between one-half and one-third of infected fetuses will have symptoms at birth and develop disease due CMV.15,16 Primary maternal infections early in gestation probably result in more severe congenital disease.16,17 For pregnant women who are naturally seropositive, that is they were infected with CMV months or years before pregnancy, the congenital infection rate is <2%, and these congenital infections infrequently result in symptomatic or severely affected infants. They may, however, have mild to moderate neurosensory hearing deficit.18 Maternal immunity to CMV impacts the frequency of viral transmission during pregnancy. Women with impaired cellular immune responses to CMV, for example those with AIDS or those receiving immunosuppressive therapy, are more likely to transmit virus to the fetus.19,20 Neutralizing titers and IgG avidity to CMV antigens are both inversely correlated with transmission.16,21 Infants born to naturally seropositive mothers receive in utero only maternal antibodies and not immune cells. Therefore, it is likely that fetal infections among women infected with CMV prior to conception are of reduced severity due to pre-existing maternal antibodies that reduce or eliminate maternal and fetal viral load. The frequency of CMV transmission to the fetus and disease is associated with viral load either in fetal amniotic fluid or in the newborn’s plasma.22
5. Placental dysfunction and the congenital CMV syndrome Many symptoms in the newborn of congenital CMV infection may not be due to viral infection of the fetus. Rather, they appear to be a consequence of CMV infection of the placenta, which impairs its capacity to provide oxygen and nutrients to the developing fetus. Several observations indicate this possibility. First, manifestations of congenital infection such as fetal growth retardation, liver disease, hematopoietic abnormalities, and splenomegaly resolve over the first weeks to months of life, concurrent with adequate oxygenation and nutrition of the newborn suggesting placental dysfunction. Second, many infants born of mothers with CMV infection are asymptomatic and develop normally, despite developing viremia in utero which continues postnatally with shedding of virus in urine and saliva for years after birth.23 Third, CMV infection is occasionally associated with a “blueberry muffin” syndrome, in which the purpurae are caused by extramedullary hematopoiesis indicative of intrauterine hypoxia. Fourth, hepatomegaly of the newborn with a congenital CMV infection is due to biliary obstruction secondary to extramedullary hematopoiesis and erythrocytic congestion which is also responsible for splenic enlargement in most symptomatic infants.24 These indicate a lack of adequate fetal oxygenation. Finally the increase in placenta size that occurs with a primary maternal CMV infection suggests that the placenta vasculature is enlarging to compensate the fetus and that the beneficial effect of CMV passive immunization with CMV hyperimmune globulin (HIG) may be due to improved placental function with enhanced supplies of oxygen, substrates, and nutritional elements to the fetus. One study has evaluated placental thickening in women with primary CMV infections during pregnancy.25 In that study the placental size of 92 women with a primary infection and 73 CMVseropositive pregnant women without primary infection were
S56
S.P. Adler, G. Nigro / Journal of Clinical Virology 46S (2009) S54–S57
evaluated. Thirty-two women received HIG to either prevent or treat intrauterine CMV infection. Placental ultrasound evaluations were performed from 16 to 36 weeks’ gestation. Women with primary CMV infection and a fetus or newborn with CMV disease had significantly (P < 0.0001) thicker placentas than women with a primary infection whose fetus or newborn was disease free. Women with a primary infection and whose fetuses were uninfected fetus still had significantly (P < 0.0001) thicker placentas than seropositive controls without infected fetuses, suggesting the placentas were infected even though the fetuses were uninfected. After primary infection, for women with or without infected fetuses or newborns, treatment with HIG was associated with significant (P < 0.001) reductions in placental thickness. Placental thickness values, predictive of primary maternal infection and/or fetal disease, were observed at each measurement from 16 to 36 weeks’ gestation, and cut-off values ranged from 22 to 35 mm, with the best sensitivity and specificity at 28 and 32 weeks.25 6. Treatment trials: prevention of fetal infection Prevention of fetal infection with a high-titer CMV immunoglobulin (HIG) preparation (Cytotect, Biotest AG) was recently studied.16 181 pregnant women with a primary CMV infection were identified. Most women were asymptomatic and identified by serologic screening. For women with a primary infection at <21 weeks’ gestation or for those who refused amniocentesis, HIG (100 U/kg of maternal weight) was administered monthly until delivery. Of 126 women (mean gestational age at infection, 14.3 ± 7 weeks) who did not receive HIG, 56% delivered infected infants, compared to 16% of 37 women (mean gestational age at infection, 13.2 ± 5.5 weeks) who received prophylactic HIG (P < 0.001). All of the infected babies were normal at birth and after at least 2 years of observation. In this study it is likely that the true efficacy of HIG may have been greater than actually observed because a few of the fetuses may have been infected in utero before HIG was administered. Although this was not a randomized controlled trial, the observations were consistent with the observations for natural infection. That is, women who have pre-pregnancy antibodies to CMV acquired by a natural infection have a markedly reduced rate of mother-to-fetus transmission of CMV.15,26
developing severe CMV disease.29 A protective and immunomodulatory role for CMV specific hyperimmunoglobulin was suggested by the reduced rate of CMV infections among preterm infants who received multiple blood transfusions.30 A multicenter prospective cohort study of 157 pregnant women with confirmed primary CMV infection evaluated the use of HIG.16 Of these 157 women, 148 were asymptomatic and were identified by routine serologic screening. Forty-five women had a primary infection more than 6 weeks before enrollment, and underwent amniocentesis to detect CMV DNA or virus in amniotic fluid. Thirtyone of these women, whose fetuses were infected, received HIG (200 U/kg of the mother’s body weight). Fourteen women with infected fetuses declined HIG and half of them delivered infants with a symptomatic CMV infection. In contrast, only 1 of the 31 women who received HIG delivered a diseased infant at birth (adjusted odds ratio, 0.02; P < 0.001). In particular, 15 treated women had fetuses with ultrasound abnormalities consistent with an intrauterine CMV infection. Fourteen infants of these 15 fetuses were healthy despite the prenatal ultrasound signs of involvement. Administration of HIG to the mother and fetal ultrasound abnormalities before treatment was independent predictors of fetal outcome (P < 0.001). The 50% pre-treatment disease rate observed in this study most likely reflects that maternal infection occurred on average at 11–12 weeks gestation. Immunological assays were performed in a subgroup of HIGtreated women.16 Women who received HIG had a significant increase (P < 0.001) in CMV-specific titers and IgG avidity immediately after HIG infusion and at the end of pregnancy, compared with untreated women. For cytokine producing cells and innate immunity (NK cells) a statistically significant decrease of approximately 33% of the percentage of the total CD16+56+ and HLA−DR+ cells and of the NK activity (at 100:1 effector-to-target ratio), and a 40% decrease in the absolute number of HLA−DR+ and CD16+56+ cells was observed in HIG-treated patients, compared to the values of untreated mothers. This suggests that HIG may have decreased the harmful effects of CMV by suppressing the production of cytokines which stimulate cell mediated fetal damage.31,32 Thus, HIG may have a direct antiviral activity due to its high neutralizing titer and/or down regulate the viral induced inflammatory effects by immunomodulation.
8. Effect of primary maternal infection on placental and ventricular size
7. Treatment trials: treatment of fetal infection Neonatal transfusion studies initially suggested the effectiveness of CMV-specific antibodies for treating CMV disease.27,28 Premature neonates born of CMV seronegative mothers acquired post-transfusion with symptomatic CMV infections, but those born of CMV-seropositive mothers remained asymptomatic after receiving the same blood products. At 3 months of age, when CMV-specific maternal antibodies had decreased to only 10–20% of their concentration at birth, newborns were still protected against
Finally the relationship between HIG treatment, ultrasound abnormalities, and fetal outcome following a primary maternal CMV infection during pregnancy has recently been reported for six additional infants.33–36 In one report (Table 2), five women had fetuses with CMV-associated cerebral and other ultrasound abnormalities.33 Three mothers received HIG during pregnancy and two did not. The ventriculomegaly of all three fetuses of
Table 2 Recent case reports of fetuses treated with hyperimmune globulin. Reference
Number of subjects
Fetal manifestations (weeks gestation)
Product used (weeks gestation)
Fetal outcome
Newborn outcome
34
1
Fetal hydrops (26 weeks)
Gammagard-Baxter (28 weeks)
Hydrops resolved
35
1
Cytogam (21 weeks)
All resolved
36
1
Placentomegaly, ascites, ecchogenic bowel, hepatomegaly (20 weeks) Fetal hydrops (17 weeks)
Cytogam (28 weeks)
Hydrops resolved
33
3
Ventriculomegaly (3 fetuses); echgenic bowel (1 fetus); hepatomegaly with ascites (1 fetus)
Cytotect-Biotest (variable)
Resolved
Died 6 h of age following delivery at 29 weeks Normal except for unilateral hearing deficit Small for gestational age GA and periventricular calcifications—normal at 9 months Normal—various ages
S.P. Adler, G. Nigro / Journal of Clinical Virology 46S (2009) S54–S57
HIG-treated mothers regressed in utero and the ascites, hepatic echodensities, periventricular echodensities, and intestinal echodensities also disappeared. Their sensorial, mental and motor development was normal at the age of 4, 4.7, and 7 years of age. In contrast both infants born of untreated mothers had signs and symptoms of severe CMV cerebropathy.33 Three other case reports (Table 2) also indicate successful treatment of fetuses infected in utero, although one infant died at birth after premature delivery but after resolutions of symptoms.34–36 As suggested by one patient listed in Table 2 and the fact that that infants born of mothers who were seropositive to CMV prior to conception often suffer from hearing deficit, although at a reduced level of severity, it is possible that passive immunization will not have a significant impact on neurosensory hearing deficit.18 9. Conclusions In conclusion, numerous observations support the likely efficacy of HIG as a treatment for CMV among women and/or fetuses infected with CMV during pregnancy. Pending the results of randomized controlled clinical trials, there has emerged a consensus among obstetricians that off-label use of HIG during pregnancy should be considered, particularly if there is sonographic evidence of fetal injury, as a possible alternative to pregnancy termination.37 The rationale for this is the availability of HIG, its lack of known toxicity, its modest cost when compared to the cost of caring for a retarded or deaf child, and in the United States, insurance reimbursement in nearly all cases. HIG should also be considered when there is a serologically confirmed primary CMV infection after conception and the maternal IgG avidity to CMV is low or amniotic fluid contains CMV or CMV DNA. If no amniocentesis is done and the maternal IgG avidity is low, monthly HIG infusions until delivery should be considered. Based on the available data, a wait and watch approach is also appropriate when the amniotic fluid is positive for CMV but ultrasound examinations are normal, including placental thickness. If maternal IgG avidity to CMV is >50%, HIG treatment should be unnecessary.16 Conflict of interest The authors have no financial conflict of interests. References 1. Stratton KR, Durch JS, Lawerence RS. Vaccines for the 21st century: a tool for decision making. Washington, DC: National Academy Press; 2000. 2. Cui X, Meza MP, Adler SP, McVoy MA. Human immune sera contain high titers of antibodies that block cytomegalovirus entry into epithelial cells but are induced at low titers by CMV vaccines. Vaccine 2008;26:5760–6. 3. Clark AL, Gall SA. Clinical uses of intravenous immunoglobulin in pregnancy. Am J Obstet Gynecol 1997;176:241–53. 4. Ballow M. Intravenous immunoglobulins: clinical experience and viral safety. J Am Pharm Assoc 2002;42:449–58. 5. Ballow M. Safety of IGIV therapy and infusion-related adverse events. Immunol Res 2007;38:122–32. 6. Schleiss MR. Comparison of vaccine strategies against congenital CMV infection in the guinea pig model. J Clin Virol 2008;41:224–30. 7. Bia FJ, Griffith BP, Tarsio M, Hsiung GD. Vaccination for the prevention of maternal and fetal infection with guinea pig cytomegalovirus. J Infect Dis 1980;142:732–8. 8. Chatterjee A, Harrison CJ, Britt WJ, Bewtra C. Modification of maternal and congenital cytomegalovirus infection by anti-glycoprotein b antibody transfer in guinea pigs. J Infect Dis 2001;183:1547–53. 9. Bratcher DF, Bourne N, Bravo FJ, Schleiss MR, Slaoui M, Myers MG, et al. Effect of passive antibody on congenital cytomegalovirus infection in guinea pigs. J Infect Dis 1995;172:944–50.
S57
10. Gabrielli L, Bonasoni P, Lazzarotto T, Lega S, Santini D, Foschini MP, et al. Histological findings in fetuses congenitally infected by cytomegalovirus. J Clin Virology; in press. 11. Cekinovic´ D, Golemac M, Pugel EP, Tomac J, Cicin-Sain L, Slavuljica I, et al. Passive immunization reduces murine cytomegalovirus-induced brain pathology in newborn mice. J Virol 2008;82:12172–80. 12. Fowler KB, Stagno S, Pass RF, Britt WJ, Boll TJ, Alford CA. The outcome of congenital cytomegalovirus infection in relation to maternal antibody status. N Engl J Med 1992;326:663–7. 13. Kenneson A, Cannon MJ. Review and meta-analysis of the epidemiology of congenital cytomegalovirus (CMV) infection. Rev Med Virol 2007;17: 253–76. 14. Bodeus M, Hubinont C, Goubau P. Increased risk of cytomegalovirus transmission in utero during late gestation. Obstet Gynecol 1999;93:658–60. 15. Enders G, Bader U, Lindemann L, Schalasta G, Daiminger A. Diagnosis of congenital cytomegalovirus infection in 189 pregnancies with known outcome. Prenat Diagn 2001;21:362–77. 16. Nigro G, Adler SP, La Torre R, Best AM. Passive immunization during pregnancy for congenital cytomegalovirus infection. N Engl J Med 2005;353: 1350–62. 17. Pass RF, Fowler KB, Boppana SB, Britt WJ, Stagno S. Congenital cytomegalovirus infection following first trimester maternal infection: symptoms at birth and outcome. J Clin Virol 2006;35:216–20. 18. Ross SA, Fowler KB, Ashrith G, Stagno S, Britt WJ, Pass RF, et al. Hearing loss in children with congenital cytomegalovirus infection born to mothers with preexisting immunity. J Pediatr 2006;148:332–6. 19. Doyle M, Atkins JT, Rivera-Matos IR. Congenital cytomegalovirus infection in infants infected with human immunodeficiency virus type 1. Pediatr Infect Dis J 1996;15:1102–6. 20. Chandwani S, Kaul A, Bebenroth D, Kim M, John DD, Fidelia A, et al. Cytomegalovirus infection in human immunodeficiency virus type 1-infected children. Pediatr Infect Dis J 1996;15:310–4. 21. Boppana SB, Rivera LB, Fowler KB, Mach M, Britt WJ. Intrauterine transmission of cytomegalovirus to infants of women with preconceptional immunity. N Engl J Med 2001;344:1366–71. 22. Lanari M, Lazzarotto T, Venturi V, Papa I, Gabrielli L, Guerra B, et al. Neonatal cytomegalovirus blood load and risk of sequelae in symptomatic and asymptomatic congenitally infected newborns. Pediatrics 2006;117: e76–83. 23. Stagno S, Britt W. Cytomegalovirus infections. In: Infectious diseases of the fetus and new born infant. 6th edition Remington and Klein; 2006, p.739–781. 24. Naeye RL. Cytomegalic inclusion disease. The fetal disorder. Am J Clin Pathol 1967;47:738–44. 25. La Torre R, Nigro G, Best AM, Adler SP. Placental enlargement is predictive of a primary maternal cytomegalovirus infection and fetal disease. Clin Infect Dis 2006;43:994–1000. 26. Fowler KB, Stagno S, Pass RF. Maternal immunity and prevention of congenital cytomegalovirus infection. JAMA 2003;289:1008–11. 27. Yeager AS, Grumet FC, Hafleigh EB, Arvin AM, Bradley JS, Prober CG. Prevention of transfusion acquired cytomegalovirus infection in newborn infants. J Pediatr 1981;98:281–7. 28. Adler SP, Chandrika T, Lawrence L, Baggett J. Cytomegalovirus infections in neonates acquired by blood transfusions. Pediatr Infect Dis J 1983;2: 114–8. 29. Adler SP, Baggett J, Wilson M, Lawrence L, McVoy M. Molecular epidemiology of cytomegalovirus transmission in a nursery: lack of evidence for nosocomial transmission. J Pediatr 1986;108:117–23. 30. Snydman DR, Werner BG, Meissner HC, et al. Use of cytomegalovirus immunoglobulin in multiple transfused premature neonates. Pediatr Infect Dis J 1995;14:34–40. 31. Sissons JG, Carmichael AJ, McKinney N, Sinclair JH, Wills MR. Human cytomegalovirus and immunopathology. Springer Semin Immunopathol 2002;24:169–85. 32. Fairweather D, Kaya Z, Shellam GR, Lawson CM, Rose NR. From infection to autoimmunity. J Autoimmun 2001;16:175–86. 33. Nigro G, La Torre R, Pentimalli H, Taverna P, Lituania M, Martinez de Tejada B, et al. Regression of fetal cerebral abnormalities by primary cytomegalovirus infection following hyperimmunoglobulin therapy. Prenat Diagn 2008;28: 512–7. 34. Sato A, Hirano H, Miura H, Hosoya N, Ogawa M, Tanaka T. Intrauterine therapy with cytomegalovirus hyperimmunoglobulin for a fetus congenitally infected with cytomegalovirus. J Obstet Gynaecol Res 2007;33:718–21. 35. Moise KJ, Wolfe H. Treatment of second trimester fetal cytomegalovirus infection with maternal hyperimmune globulin. Prenat Diagn 2008;28:264–5. 36. Moxley K, Knudtson EJ. Resolution of hydrops secondary to cytomegalovirus after maternal and fetal treatment with human cytomegalovirus hyperimmune globulin. Obstet Gynecol 2008;111:524–6. 37. Duff P. A thoughtful algorithm for the accurate diagnosis of primary CMV infection in pregnancy. Am J Obstet Gynecol 2007;196:196–7.
Contents lists available at ScienceDirect
Journal of Clinical Virology journal homepage: www.elsevier.com/locate/jcv
Findings and conclusions from CMV hyperimmune globulin treatment trials Stuart P. Adler a,∗ , Giovanni Nigro b a b
Department of Pediatrics, Virginia Commonwealth University, Medical College of Virginia Campus, Box 163, Richmond, VA 23298, United States Department of Pediatrics, University of L’Aquila, L’Aquila, Italy
a r t i c l e
i n f o
Article history: Received 31 March 2009 Received in revised form 25 August 2009 Accepted 29 August 2009 Keywords: Cytomegalovirus Passive immunization Hyperimmune globulin Pregnancy Congenital CMV infection CMV antibodies CMV immunity
a b s t r a c t A primary maternal infection with cytomegalovirus (CMV) either during or just before pregnancy accounts for the majority of congenital infections where the baby is symptomatic at birth. Following a primary maternal infection, depending on gestational age, between one quarter and three quarters of fetuses will become infected, and approximately one-third of infected fetuses will have symptoms at birth. Experiments using animal models of CMV infection and observational studies in humans indicate that administration of a CMV hyperimmune globulin (HIG) to the pregnant woman with a primary CMV infection should be effective for both the treatment and prevention of fetal infection. The HIG probably acts by reducing placental inflammation, neutralizing virus with high avidity antibodies, and perhaps by reducing cytokine mediated cellular immune responses. © 2009 Elsevier B.V. All rights reserved.
1. Introduction In 1999, a United States Institute of Medicine report called “Vaccines for the 21st Century” identified the need for a vaccine for women of childbearing age to protect against CMV as a high priority for new vaccines.1 This was based on cost effectiveness and improvement in the quality of life a vaccine would afford affected children. Pending the availability of an active vaccine, recent animal and human studies indicate that fetal CMV disease after a primary maternal infection during pregnancy may be reversed or modified by passive immunization with high avidity neutralizing antibodies directed against CMV. This article will review the evidence indicating that passive immunization should be highly effective for preventing or treating CMV infections of the fetus among women with a primary CMV infection during pregnancy. 2. Immunoglobulin availability One reason to consider passive immunization for treating or preventing CMV infections of the fetus is that appropriate immunoglobulin preparations are available. Currently, worldwide there are three available sources of intravenous immunoglobulin enriched for antibodies against CMV. In the US the available CMV hyperimmune globulin is Cytogam (CSL Behring) and in Europe the product is Cyotect (Biotest AG). The Australian Red Cross blood
services also produce an intravenous immunoglobulin preparation enriched for antibodies to CMV. We have tested the neutralizing activity of each preparation by measuring the titer of antibodies directed against CMV glycoprotein B, a CMV envelope protein, which induces the majority of neutralizing activity directed against CMV and against viral entry into endothelial cells. Each product has an anti-gB titer of 1/400,000. This is approximately 2–4-fold higher than that observed among individuals naturally seropositive for CMV. Cytogam and Cytotect also contain very high titers of antibodies that block viral entry into endothelial and epithelial cells.2 Regarding safety, intravenous immunoglobulins are the most purified among the blood derivatives, including albumin, and are the only derivatives which can be pasteurized. Intravenous immunoglobulins are used each year to safely treat many tens of thousands of patients such as transplant patients and those with Kawasaki’s disease, immune deficiencies, thrombocyptopenia, etc. Immunoglobulin has been used safely in pregnancy for decades,3 primarily to treat blood group incompatibilities but also for passive immunization against rubella, hepatitis A and B, varicella, and measles. A few batches of intramuscularly (not intravenous) administered immunoglobulin were contaminated with hepatitis C in the late 1970s. For intravenous immunoglobulins, in over 17 years of use, no case of viral transmission has been reported.4,5 3. Animal models
∗ Corresponding author. E-mail address: [email protected] (S.P. Adler). 1386-6532/$ – see front matter © 2009 Elsevier B.V. All rights reserved. doi:10.1016/j.jcv.2009.08.017
Another reason to consider passive immunization for treating or preventing CMV infections of the fetus, is based on
S.P. Adler, G. Nigro / Journal of Clinical Virology 46S (2009) S54–S57 Table 1 Summary of passive immunization studies using the guinea pig model. Reference
Immune serum to
Controls
Treatment group
Number of pups surviving/number observed (%)
Number of pups surviving/number observed (%) 34/42 (81)a 33/46 (77)b 20/23 (87) 18/25 (72)
7
Whole virus
23/45 (51)
8 9
Guinea pig gB Whole virus
2/12 (17) 13/26 (50)
a b
Immune serum administered after viral challenge of the pregnant dame. Immune serum administered before viral challenge of the pregnant dame.
the effectiveness observed in animal models. The guinea pig model of cytomegalovirus (GPCMV) infection is useful because GPCMV crosses the guinea pig placenta, causing infection in utero and the structure of the guinea pig placenta is similar to the human placenta.6 In the guinea pig model fetal infection leads to fetal death, so pup survival is the endpoint used in guinea pig experiments.6 Thus, the guinea pig model has been used frequently to study the role of antibodies induced by either active or passive immunization to interrupt intrauterine transmission and/or protect the fetus. The guinea pig model has evaluated passive immunization for protective effects on the fetus.7–9 In these studies pregnant guinea pigs were challenged with guinea pig (gp) CMV before or after passive administration of neutralizing anti-sera to either whole virus or gB, a glycoprotein that induces neutralizing antibodies.7–9 In two separate reports passive administration of immune serum to whole virus significantly increased fetal survival (Table 1) even though it did not affect the rate of fetal infection, indicating that the immune serum was therapeutic. In other guinea pig experiments with immune sera to purified gB, there was reduced fetal infection, placental inflammation, fetal death, and enhanced fetal growth.9 In these experiments fetal survival was enhanced for dames treated with immune globulin to gpCMV gB compared with controls (Table 1). This effect was independent of whether immune globulin was administered before or after the challenge virus.9 Additional high-titer immune globulin given before or after maternal challenge significantly reduced the rate of fetal infection from 39% (9 of 23 fetuses infected) to 0% (0 of 18 fetuses infected).9 Immune globulin to gB, administered before or after maternal challenge, also significantly reduced placental inflammation and enhanced fetal growth, as measured by fetal weight. In the guinea pig model, there are several plausible mechanisms for the therapeutic efficacy of passive immunization: immunomodulatory effects, reduction of maternal viremia and viral load, and/or decreased placental inflammation resulting in increased blood flow with enhanced fetal nutrition, oxygenation, and survival. The brains of a high proportion of human fetuses infected with CMV in utero after a primary maternal infection contain CMV and an associated inflammatory response.10 Therefore it is of interest to note a recent study of passive immunization that used a mouse model.11 Mouse CMV does not cross the mouse placenta, so mouse CMV was injected into the peritoneal cavity of newborn mice.11 This led to viral infection of the brains of the infant mice with associated inflammatory lesions in the brains. These lesions consisted of mononuclear cell infiltrations and prominent glial nodules. Treatment of the newborn mice with either immune sera or monoclonal antibodies directed against the mouse CMV gB resulted in markedly reduced amounts of virus in the brains as well as over 5-fold reductions in inflammatory lesions in the brain. These observations suggested that antiviral antibodies limited both viral replication in the brain and viral induced brain damage.
S55
4. Maternal immunity antibodies suggests a role for CMV-specific maternal antibodies A mother’s first infection with CMV during pregnancy causes the majority of congenital infections where the baby has neurosensory hearing deficit and/or mental retardation.12,13 If a first maternal CMV infection occurs in the first trimester, approximately 25% of fetuses will be infected; in the second trimester approximately 50%; in the third approximately 75% will be infected.14 Between one-half and one-third of infected fetuses will have symptoms at birth and develop disease due CMV.15,16 Primary maternal infections early in gestation probably result in more severe congenital disease.16,17 For pregnant women who are naturally seropositive, that is they were infected with CMV months or years before pregnancy, the congenital infection rate is <2%, and these congenital infections infrequently result in symptomatic or severely affected infants. They may, however, have mild to moderate neurosensory hearing deficit.18 Maternal immunity to CMV impacts the frequency of viral transmission during pregnancy. Women with impaired cellular immune responses to CMV, for example those with AIDS or those receiving immunosuppressive therapy, are more likely to transmit virus to the fetus.19,20 Neutralizing titers and IgG avidity to CMV antigens are both inversely correlated with transmission.16,21 Infants born to naturally seropositive mothers receive in utero only maternal antibodies and not immune cells. Therefore, it is likely that fetal infections among women infected with CMV prior to conception are of reduced severity due to pre-existing maternal antibodies that reduce or eliminate maternal and fetal viral load. The frequency of CMV transmission to the fetus and disease is associated with viral load either in fetal amniotic fluid or in the newborn’s plasma.22
5. Placental dysfunction and the congenital CMV syndrome Many symptoms in the newborn of congenital CMV infection may not be due to viral infection of the fetus. Rather, they appear to be a consequence of CMV infection of the placenta, which impairs its capacity to provide oxygen and nutrients to the developing fetus. Several observations indicate this possibility. First, manifestations of congenital infection such as fetal growth retardation, liver disease, hematopoietic abnormalities, and splenomegaly resolve over the first weeks to months of life, concurrent with adequate oxygenation and nutrition of the newborn suggesting placental dysfunction. Second, many infants born of mothers with CMV infection are asymptomatic and develop normally, despite developing viremia in utero which continues postnatally with shedding of virus in urine and saliva for years after birth.23 Third, CMV infection is occasionally associated with a “blueberry muffin” syndrome, in which the purpurae are caused by extramedullary hematopoiesis indicative of intrauterine hypoxia. Fourth, hepatomegaly of the newborn with a congenital CMV infection is due to biliary obstruction secondary to extramedullary hematopoiesis and erythrocytic congestion which is also responsible for splenic enlargement in most symptomatic infants.24 These indicate a lack of adequate fetal oxygenation. Finally the increase in placenta size that occurs with a primary maternal CMV infection suggests that the placenta vasculature is enlarging to compensate the fetus and that the beneficial effect of CMV passive immunization with CMV hyperimmune globulin (HIG) may be due to improved placental function with enhanced supplies of oxygen, substrates, and nutritional elements to the fetus. One study has evaluated placental thickening in women with primary CMV infections during pregnancy.25 In that study the placental size of 92 women with a primary infection and 73 CMVseropositive pregnant women without primary infection were
S56
S.P. Adler, G. Nigro / Journal of Clinical Virology 46S (2009) S54–S57
evaluated. Thirty-two women received HIG to either prevent or treat intrauterine CMV infection. Placental ultrasound evaluations were performed from 16 to 36 weeks’ gestation. Women with primary CMV infection and a fetus or newborn with CMV disease had significantly (P < 0.0001) thicker placentas than women with a primary infection whose fetus or newborn was disease free. Women with a primary infection and whose fetuses were uninfected fetus still had significantly (P < 0.0001) thicker placentas than seropositive controls without infected fetuses, suggesting the placentas were infected even though the fetuses were uninfected. After primary infection, for women with or without infected fetuses or newborns, treatment with HIG was associated with significant (P < 0.001) reductions in placental thickness. Placental thickness values, predictive of primary maternal infection and/or fetal disease, were observed at each measurement from 16 to 36 weeks’ gestation, and cut-off values ranged from 22 to 35 mm, with the best sensitivity and specificity at 28 and 32 weeks.25 6. Treatment trials: prevention of fetal infection Prevention of fetal infection with a high-titer CMV immunoglobulin (HIG) preparation (Cytotect, Biotest AG) was recently studied.16 181 pregnant women with a primary CMV infection were identified. Most women were asymptomatic and identified by serologic screening. For women with a primary infection at <21 weeks’ gestation or for those who refused amniocentesis, HIG (100 U/kg of maternal weight) was administered monthly until delivery. Of 126 women (mean gestational age at infection, 14.3 ± 7 weeks) who did not receive HIG, 56% delivered infected infants, compared to 16% of 37 women (mean gestational age at infection, 13.2 ± 5.5 weeks) who received prophylactic HIG (P < 0.001). All of the infected babies were normal at birth and after at least 2 years of observation. In this study it is likely that the true efficacy of HIG may have been greater than actually observed because a few of the fetuses may have been infected in utero before HIG was administered. Although this was not a randomized controlled trial, the observations were consistent with the observations for natural infection. That is, women who have pre-pregnancy antibodies to CMV acquired by a natural infection have a markedly reduced rate of mother-to-fetus transmission of CMV.15,26
developing severe CMV disease.29 A protective and immunomodulatory role for CMV specific hyperimmunoglobulin was suggested by the reduced rate of CMV infections among preterm infants who received multiple blood transfusions.30 A multicenter prospective cohort study of 157 pregnant women with confirmed primary CMV infection evaluated the use of HIG.16 Of these 157 women, 148 were asymptomatic and were identified by routine serologic screening. Forty-five women had a primary infection more than 6 weeks before enrollment, and underwent amniocentesis to detect CMV DNA or virus in amniotic fluid. Thirtyone of these women, whose fetuses were infected, received HIG (200 U/kg of the mother’s body weight). Fourteen women with infected fetuses declined HIG and half of them delivered infants with a symptomatic CMV infection. In contrast, only 1 of the 31 women who received HIG delivered a diseased infant at birth (adjusted odds ratio, 0.02; P < 0.001). In particular, 15 treated women had fetuses with ultrasound abnormalities consistent with an intrauterine CMV infection. Fourteen infants of these 15 fetuses were healthy despite the prenatal ultrasound signs of involvement. Administration of HIG to the mother and fetal ultrasound abnormalities before treatment was independent predictors of fetal outcome (P < 0.001). The 50% pre-treatment disease rate observed in this study most likely reflects that maternal infection occurred on average at 11–12 weeks gestation. Immunological assays were performed in a subgroup of HIGtreated women.16 Women who received HIG had a significant increase (P < 0.001) in CMV-specific titers and IgG avidity immediately after HIG infusion and at the end of pregnancy, compared with untreated women. For cytokine producing cells and innate immunity (NK cells) a statistically significant decrease of approximately 33% of the percentage of the total CD16+56+ and HLA−DR+ cells and of the NK activity (at 100:1 effector-to-target ratio), and a 40% decrease in the absolute number of HLA−DR+ and CD16+56+ cells was observed in HIG-treated patients, compared to the values of untreated mothers. This suggests that HIG may have decreased the harmful effects of CMV by suppressing the production of cytokines which stimulate cell mediated fetal damage.31,32 Thus, HIG may have a direct antiviral activity due to its high neutralizing titer and/or down regulate the viral induced inflammatory effects by immunomodulation.
8. Effect of primary maternal infection on placental and ventricular size
7. Treatment trials: treatment of fetal infection Neonatal transfusion studies initially suggested the effectiveness of CMV-specific antibodies for treating CMV disease.27,28 Premature neonates born of CMV seronegative mothers acquired post-transfusion with symptomatic CMV infections, but those born of CMV-seropositive mothers remained asymptomatic after receiving the same blood products. At 3 months of age, when CMV-specific maternal antibodies had decreased to only 10–20% of their concentration at birth, newborns were still protected against
Finally the relationship between HIG treatment, ultrasound abnormalities, and fetal outcome following a primary maternal CMV infection during pregnancy has recently been reported for six additional infants.33–36 In one report (Table 2), five women had fetuses with CMV-associated cerebral and other ultrasound abnormalities.33 Three mothers received HIG during pregnancy and two did not. The ventriculomegaly of all three fetuses of
Table 2 Recent case reports of fetuses treated with hyperimmune globulin. Reference
Number of subjects
Fetal manifestations (weeks gestation)
Product used (weeks gestation)
Fetal outcome
Newborn outcome
34
1
Fetal hydrops (26 weeks)
Gammagard-Baxter (28 weeks)
Hydrops resolved
35
1
Cytogam (21 weeks)
All resolved
36
1
Placentomegaly, ascites, ecchogenic bowel, hepatomegaly (20 weeks) Fetal hydrops (17 weeks)
Cytogam (28 weeks)
Hydrops resolved
33
3
Ventriculomegaly (3 fetuses); echgenic bowel (1 fetus); hepatomegaly with ascites (1 fetus)
Cytotect-Biotest (variable)
Resolved
Died 6 h of age following delivery at 29 weeks Normal except for unilateral hearing deficit Small for gestational age GA and periventricular calcifications—normal at 9 months Normal—various ages
S.P. Adler, G. Nigro / Journal of Clinical Virology 46S (2009) S54–S57
HIG-treated mothers regressed in utero and the ascites, hepatic echodensities, periventricular echodensities, and intestinal echodensities also disappeared. Their sensorial, mental and motor development was normal at the age of 4, 4.7, and 7 years of age. In contrast both infants born of untreated mothers had signs and symptoms of severe CMV cerebropathy.33 Three other case reports (Table 2) also indicate successful treatment of fetuses infected in utero, although one infant died at birth after premature delivery but after resolutions of symptoms.34–36 As suggested by one patient listed in Table 2 and the fact that that infants born of mothers who were seropositive to CMV prior to conception often suffer from hearing deficit, although at a reduced level of severity, it is possible that passive immunization will not have a significant impact on neurosensory hearing deficit.18 9. Conclusions In conclusion, numerous observations support the likely efficacy of HIG as a treatment for CMV among women and/or fetuses infected with CMV during pregnancy. Pending the results of randomized controlled clinical trials, there has emerged a consensus among obstetricians that off-label use of HIG during pregnancy should be considered, particularly if there is sonographic evidence of fetal injury, as a possible alternative to pregnancy termination.37 The rationale for this is the availability of HIG, its lack of known toxicity, its modest cost when compared to the cost of caring for a retarded or deaf child, and in the United States, insurance reimbursement in nearly all cases. HIG should also be considered when there is a serologically confirmed primary CMV infection after conception and the maternal IgG avidity to CMV is low or amniotic fluid contains CMV or CMV DNA. If no amniocentesis is done and the maternal IgG avidity is low, monthly HIG infusions until delivery should be considered. Based on the available data, a wait and watch approach is also appropriate when the amniotic fluid is positive for CMV but ultrasound examinations are normal, including placental thickness. If maternal IgG avidity to CMV is >50%, HIG treatment should be unnecessary.16 Conflict of interest The authors have no financial conflict of interests. References 1. Stratton KR, Durch JS, Lawerence RS. Vaccines for the 21st century: a tool for decision making. Washington, DC: National Academy Press; 2000. 2. Cui X, Meza MP, Adler SP, McVoy MA. Human immune sera contain high titers of antibodies that block cytomegalovirus entry into epithelial cells but are induced at low titers by CMV vaccines. Vaccine 2008;26:5760–6. 3. Clark AL, Gall SA. Clinical uses of intravenous immunoglobulin in pregnancy. Am J Obstet Gynecol 1997;176:241–53. 4. Ballow M. Intravenous immunoglobulins: clinical experience and viral safety. J Am Pharm Assoc 2002;42:449–58. 5. Ballow M. Safety of IGIV therapy and infusion-related adverse events. Immunol Res 2007;38:122–32. 6. Schleiss MR. Comparison of vaccine strategies against congenital CMV infection in the guinea pig model. J Clin Virol 2008;41:224–30. 7. Bia FJ, Griffith BP, Tarsio M, Hsiung GD. Vaccination for the prevention of maternal and fetal infection with guinea pig cytomegalovirus. J Infect Dis 1980;142:732–8. 8. Chatterjee A, Harrison CJ, Britt WJ, Bewtra C. Modification of maternal and congenital cytomegalovirus infection by anti-glycoprotein b antibody transfer in guinea pigs. J Infect Dis 2001;183:1547–53. 9. Bratcher DF, Bourne N, Bravo FJ, Schleiss MR, Slaoui M, Myers MG, et al. Effect of passive antibody on congenital cytomegalovirus infection in guinea pigs. J Infect Dis 1995;172:944–50.
S57
10. Gabrielli L, Bonasoni P, Lazzarotto T, Lega S, Santini D, Foschini MP, et al. Histological findings in fetuses congenitally infected by cytomegalovirus. J Clin Virology; in press. 11. Cekinovic´ D, Golemac M, Pugel EP, Tomac J, Cicin-Sain L, Slavuljica I, et al. Passive immunization reduces murine cytomegalovirus-induced brain pathology in newborn mice. J Virol 2008;82:12172–80. 12. Fowler KB, Stagno S, Pass RF, Britt WJ, Boll TJ, Alford CA. The outcome of congenital cytomegalovirus infection in relation to maternal antibody status. N Engl J Med 1992;326:663–7. 13. Kenneson A, Cannon MJ. Review and meta-analysis of the epidemiology of congenital cytomegalovirus (CMV) infection. Rev Med Virol 2007;17: 253–76. 14. Bodeus M, Hubinont C, Goubau P. Increased risk of cytomegalovirus transmission in utero during late gestation. Obstet Gynecol 1999;93:658–60. 15. Enders G, Bader U, Lindemann L, Schalasta G, Daiminger A. Diagnosis of congenital cytomegalovirus infection in 189 pregnancies with known outcome. Prenat Diagn 2001;21:362–77. 16. Nigro G, Adler SP, La Torre R, Best AM. Passive immunization during pregnancy for congenital cytomegalovirus infection. N Engl J Med 2005;353: 1350–62. 17. Pass RF, Fowler KB, Boppana SB, Britt WJ, Stagno S. Congenital cytomegalovirus infection following first trimester maternal infection: symptoms at birth and outcome. J Clin Virol 2006;35:216–20. 18. Ross SA, Fowler KB, Ashrith G, Stagno S, Britt WJ, Pass RF, et al. Hearing loss in children with congenital cytomegalovirus infection born to mothers with preexisting immunity. J Pediatr 2006;148:332–6. 19. Doyle M, Atkins JT, Rivera-Matos IR. Congenital cytomegalovirus infection in infants infected with human immunodeficiency virus type 1. Pediatr Infect Dis J 1996;15:1102–6. 20. Chandwani S, Kaul A, Bebenroth D, Kim M, John DD, Fidelia A, et al. Cytomegalovirus infection in human immunodeficiency virus type 1-infected children. Pediatr Infect Dis J 1996;15:310–4. 21. Boppana SB, Rivera LB, Fowler KB, Mach M, Britt WJ. Intrauterine transmission of cytomegalovirus to infants of women with preconceptional immunity. N Engl J Med 2001;344:1366–71. 22. Lanari M, Lazzarotto T, Venturi V, Papa I, Gabrielli L, Guerra B, et al. Neonatal cytomegalovirus blood load and risk of sequelae in symptomatic and asymptomatic congenitally infected newborns. Pediatrics 2006;117: e76–83. 23. Stagno S, Britt W. Cytomegalovirus infections. In: Infectious diseases of the fetus and new born infant. 6th edition Remington and Klein; 2006, p.739–781. 24. Naeye RL. Cytomegalic inclusion disease. The fetal disorder. Am J Clin Pathol 1967;47:738–44. 25. La Torre R, Nigro G, Best AM, Adler SP. Placental enlargement is predictive of a primary maternal cytomegalovirus infection and fetal disease. Clin Infect Dis 2006;43:994–1000. 26. Fowler KB, Stagno S, Pass RF. Maternal immunity and prevention of congenital cytomegalovirus infection. JAMA 2003;289:1008–11. 27. Yeager AS, Grumet FC, Hafleigh EB, Arvin AM, Bradley JS, Prober CG. Prevention of transfusion acquired cytomegalovirus infection in newborn infants. J Pediatr 1981;98:281–7. 28. Adler SP, Chandrika T, Lawrence L, Baggett J. Cytomegalovirus infections in neonates acquired by blood transfusions. Pediatr Infect Dis J 1983;2: 114–8. 29. Adler SP, Baggett J, Wilson M, Lawrence L, McVoy M. Molecular epidemiology of cytomegalovirus transmission in a nursery: lack of evidence for nosocomial transmission. J Pediatr 1986;108:117–23. 30. Snydman DR, Werner BG, Meissner HC, et al. Use of cytomegalovirus immunoglobulin in multiple transfused premature neonates. Pediatr Infect Dis J 1995;14:34–40. 31. Sissons JG, Carmichael AJ, McKinney N, Sinclair JH, Wills MR. Human cytomegalovirus and immunopathology. Springer Semin Immunopathol 2002;24:169–85. 32. Fairweather D, Kaya Z, Shellam GR, Lawson CM, Rose NR. From infection to autoimmunity. J Autoimmun 2001;16:175–86. 33. Nigro G, La Torre R, Pentimalli H, Taverna P, Lituania M, Martinez de Tejada B, et al. Regression of fetal cerebral abnormalities by primary cytomegalovirus infection following hyperimmunoglobulin therapy. Prenat Diagn 2008;28: 512–7. 34. Sato A, Hirano H, Miura H, Hosoya N, Ogawa M, Tanaka T. Intrauterine therapy with cytomegalovirus hyperimmunoglobulin for a fetus congenitally infected with cytomegalovirus. J Obstet Gynaecol Res 2007;33:718–21. 35. Moise KJ, Wolfe H. Treatment of second trimester fetal cytomegalovirus infection with maternal hyperimmune globulin. Prenat Diagn 2008;28:264–5. 36. Moxley K, Knudtson EJ. Resolution of hydrops secondary to cytomegalovirus after maternal and fetal treatment with human cytomegalovirus hyperimmune globulin. Obstet Gynecol 2008;111:524–6. 37. Duff P. A thoughtful algorithm for the accurate diagnosis of primary CMV infection in pregnancy. Am J Obstet Gynecol 2007;196:196–7.