Simultaneous congenital infection with Epstein-Barr virus and cytomegalovirus

Cytomegalovirus and Epstein-Barr virus may be associated with some cases of cerebral palsy

OBJECTIVE

Intrauterine infection is a risk factor for cerebral palsy. Previous work reported a high frequency of viral DNA in newborn screening cards from cerebral palsy cases and controls possibly due to contamination.

METHODS

Retrospective case-control study using improved methodologies to minimize contamination during PCR-based detection of viral DNA sequences. Newborn screening cards of 339 Caucasian children with cerebral palsy and 594 controls were examined. Viruses tested were herpes simplex viruses 1 and 2 (HSV1 and 2), varicella zoster virus (VZV), Epstein-Barr virus (EBV), cytomegalovirus (CMV), human herpes viruses 6, 7 and 8 (HHV6, HHV7 and HHV8), and parvovirus B19. Genotyping was performed on DNA extracted from dried blood spots.

RESULTS

CMV and EBV were detected in 5 (1.5%) and 3 (0.9%) of 339 cases, respectively, but not in controls (p = 0.047 and 0.006). Frequencies of detection of the other viruses examined were similar for cases and controls. DNA from at least one of the nine viruses tested was found in 4.4% of cases and 3.1% of controls [OR 1.4 95% CI (0.71-2.76)].

CONCLUSION

Evidence of congenital viral infection was uncommon in cases of cerebral palsy and controls. However, CMV and EBV were significantly associated with cerebral palsy.

Risk of transmission of herpesviruses through cord blood transplantation

Cord blood (CB) progenitor cells are increasingly used for transplantation in children because of the lower risk of graft-versus-host disease compared with unrelated bone marrow and comparable rates of disease-free survival. There is concern that CB might carry a higher risk of opportunistic infections. Human herpesviruses (HHV) are common pathogens in transplant recipients. CB donors are routinely tested for the presence of anti-cytomegalovirus (CMV) immunoglobulin M to reduce the risk of collecting CMV-infected CB. To assess the incidence of beta and gamma HHV infection of CB collected under standard procedures, we tested 362 CB samples for the presence of CMV; HHV-6, -7, and -8; and Epstein-Barr virus DNA by polymerase chain reaction. HHV-6 DNA was found in 2 samples, yielding an incidence of 0.55% (95% confidence interval, 0.1%-2%). None of the other viral DNAs was found, resulting in a 95% confidence interval of 0% to 1% for the incidence of CMV, Epstein-Barr virus, HHV-7, and HHV-8. Because the seroprevalence of HHV-8 among the CB donors in this study was only 4%, these findings cannot be extended to HHV-8-endemic areas. Our data show that screening prospective CB donors with anti-CMV immunoglobulin M practically eliminates the risk of CB CMV transmission, but HHV-6 warrants CB testing by polymerase chain reaction.

Susceptibility of mouse mammary glands to murine gammaherpesvirus 72 (MHV-72) infection: evidence of MHV-72 transmission via breast milk

Murine gammaherpesvirus 72 (MHV-72) is a virus of wild rodents and serves as a convenient small animal model to understand the pathogenesis of Epstein-Barr virus (EBV) and human herpesvirus 8 (HHV8) infection. In laboratory mice MHV-72 causes an acute infection of lung epithelial cells and establishes the latency in B lymphocytes. In this study, we investigated athymic nude and immunocompetent mice for distribution of virus in organs after infection with MHV-72. Ten days following subcutaneous dorsal injection of nude mice, virus replicated in lungs, lymphoid organs, salivary glands and also in mammary glands. The virus titre decreased by day 21 post-infection in former tissues, but increased in mammary glands. Presence of virus DNA sequences was detected in the lymphoid and non-lymphoid tissues until the death of the animals (about 1 month post-infection). Infection of immunocompetent mice with MHV-72 induced replication of virus up to 42 days post-infection in mammary glands reaching the highest level of infectious virus at day 8 post-infection. These data show that there is latent infection in mice never detected before. Moreover, virus DNA was detected using nested PCR (by amplification of a portion of gp150 gene sequence) in the mammary glands and the milk of mouse mothers infected with MHV-72 2 days before delivery. We demonstrated the presence of virus DNA also in the milk removed from the stomach of non-infected newborn mice, which were nourished by infected mothers (wet-nurses) for 1 or 2 days. The failure to detect the virus DNA in newborn mice lungs confirmed that they did not become infected from wet-nurses by the intranasal route. This suggests that MHV may be naturally transmitted to newborn mice via breast milk.

Epstein-Barr virus permissively infects human syncytiotrophoblasts in vitro and induces replication of human T cell leukemia-lymphoma virus type I in dually infected cells

Epstein-Barr virus (EBV) and human immunodeficiency virus type 1 (HIV-1), as well as human T-cell leukemia-lymphoma virus type I (HTLV-I), may interact in the pathogenesis of human retroviral infections. The placental syncytiotrophoblast layer represents a barrier protecting the fetal compartment from exposure to retroviruses. We studied the interactions of EBV with HIV-1 and HTLV-I in human term syncytiotrophoblast cells to investigate the significance of double infections in transplacental transmission of human retroviruses. We found that syncytiotrophoblast cells could be productively infected with EBV. Dual infection of the cells with EBV and HTLV-I resulted in full replication cycle of otherwise latent HTLV-I. In contrast, the restricted permissiveness of syncytiotrophoblasts for HIV-1 was not influenced by coinfection of the cells with EBV. Infection of syncytiotrophoblast cells with EBV, but not HTLV-I, induced interleukin-2 and interleukin-6 secretion, and augmented secretion occurred on coinfection with both viruses. Coinfection of syncytiotrophoblast cells with EBV and HTLV-I induced tumor necrosis factor-beta and transforming growth factor-beta 1 secretion, but infection with either virus alone did not lead to secretion of these cytokines. Permissive replication cycle of HTLV-I was induced by the EBV immediate-early gene product Zta. Pseudotype formation between EBV and HTLV-I in coinfected syncytiotrophoblast cells was not found. Our data suggest that activation of HTLV-I gene expression by EBV in coinfected syncytiotrophoblast cells may be a mechanism for transplacental transmission of HTLV-I.

Study of mother-to-child Epstein-Barr virus transmission by means of nested PCRs

The aim of this study was to investigate the possibility of vertical Epstein-Barr virus (EBV) transmission. We developed two nested-PCR methods for amplifying distinct regions of EBV DNA (BNRF1 and BamHI W) in circulating lymphocytes. Nested PCR was applied to samples obtained from 67 mother-infant pairs within 1 week of birth. We also tested samples from 16 neonates born to human immunodeficiency virus (HIV)-infected mothers to determine whether HIV increases the potential risk of vertical EBV transmission. About half of the 67 women in the first population were positive by nested PCR. Two neonates born to EBV PCR-positive women were also PCR positive. One of the 16 neonates born to HIV-infected women was PCR positive for EBV. These results strongly support the possibility of EBV transmission in utero or during delivery but do not suggest that HIV infection increases this risk. Further studies are required to confirm these findings, to identify the precise mode of vertical EBV transmission, and to determine the outcome for infants who are positive at birth for EBV DNA by nested PCR.

Viral infections in the dental setting: potential effects on pregnant HCWs

Occupational exposure of pregnant health care workers to infectious diseases may cause a variety of effects. This article reviews potential effects of viral infections in pregnant health care workers by pathogens transmittable in a dental setting.

Epstein-Barr virus infection and associated diseases in children. I. Pathogenesis, epidemiology and clinical aspects

Epstein-Barr virus (EBV), an ubiquitous human B lymphotropic virus, is the cause of infectious mononucleosis. Moreover, EBV infection can be followed by lymphoproliferative diseases in patients with inherited and acquired immunodeficiencies. Primary EBV infection may be a threat to all children after marrow or organ transplantation or those receiving chronic immunosuppressive treatment for various other reasons. The virus has been also implicated in the pathogenesis of different malignant tumours such as Burkitt lymphoma, nasopharyngeal carcinoma, Hodgkin disease and some T-cell lymphomas. This review focuses on various aspects of virus-host interactions, immune mechanisms of the host, and the still experimental therapeutic approaches in EBV-associated diseases.

Cytomegalovirus infects human lymphocytes and monocytes: virus expression is restricted to immediate-early gene products

In this investigation, we studied the ability of human cytomegalovirus to infect peripheral blood mononuclear cells. With monoclonal antibody technology, we demonstrated that cytomegalovirus could infect human lymphocytes of T- and B-cell lineage, natural killer cells, and monocytes. Furthermore, virus expression was limited to the synthesis of immediate-early cytomegalovirus polypeptides. These peripheral blood mononuclear cells did not produce infectious virus, nor were mature virions visualized by electron microscopy. This abortive infection of mononuclear cells was most convincingly shown with stocks of cytomegalovirus that had been recently isolated from infected patients and passaged minimally in fibroblasts. This argues for an increased lymphotropic effect of some isolates of cytomegalovirus, compared to strains of virus that are extensively adapted to growth in fibroblasts. Furthermore, immunocompetent cells that were shown to be abortively infected with cytomegalovirus lost selected differentiated functions.

Epstein-Barr virus infections in pregnancy: a prospective study

We studied 4063 pregnant women during 4108 gestations for evidence of infection with Epstein-Barr virus. Forty-six (1.1%) were susceptible early in gestation, and only three showed seroconversion. Two of the infants born to these three women were normal, one had tricuspid atresia. None of the infants had IgM antibodies to EBV at birth, and their cord blood lymphocytes did not give rise spontaneously to EBV-carrying lymphoblastoid cell lines. Thus we were unable to document intrauterine infection with EBV.

Epstein-Barr virus in normal pregnant women

Acquired immune suppression accompanying normal pregnancy may be associated with reactivation of Epstein-Barr virus (EBV). Pregnant women with reactivated EBV having anti-EA antibodies show high titers of antiviral capsid antigen (VCA) geometric mean titers (GMT) of 522 versus 170 in those lacking anti-early antigen (EA). Among twenty-seven seropositive women at parturition, 17 (63%) had generated antibody to EA, and all 27 (100%) demonstrated significant increases in antibody to VCA (p less than 0.01). In contrast, antibody titers to cytomegalovirus, herpes hominis, varicella-zoster, and rubella viruses in the pregnant women were comparable to those found in nonpregnant controls. (Am J Reprod Immunol. 1982; 2:217-221.)