title: Epstein-Barr virus (EBV)-specific cell-mediated and humoral immune responses in ataxia-telangectasia patients.
abstract: As a part of studies on cell-mediated immune (CMI) responses of immunocompromised, Epstein-Barr virus (EBV)-infected patients who can or cannot restrict the proliferation of EBV-transformed B cells, we have studied 16 Turkish patients with ataxia-telangectasia (AT). Fifteen were EBV seropositive; one was seronegative. Among the seropositives, eight had no or only low anti-EBV-determined nuclear antigen (EBNA) antibody titers, while seven had normal anti-EBNA levels. EBV-seropositive and -seronegative healthy Turkish children were used as controls. We have particularly asked the question whether low EBNA antibody titers can be correlated with the level of EBV-specific and -nonspecific cell-mediated immunity. Non-EBV-specific tests included cell count, phenotypical characterization with monoclonal antibodies, assessment of natural killer (NK)-cell activity, and ability to suppress mitogen-induced immunoglobulin production. Two EBV-specific CMI tests were used: outgrowth inhibition (OI) and leukocyte migration inhibition (LMI). The majority of the patients of the low-EBNA antibody group was IgA deficient and had high levels of alpha-fetoprotein (a-FP). Cells reacting with OKT8 monoclonal antibody predominated in both AT patient groups. In contrast, the suppressor activity was present in only a few patients and NK and interferon-activated killing (IAK) activities were normal. EBV-specific cell-mediated responses were defective in seven of eight patients in the low-anti-EBNA group and five of seven patients in the group with normal anti-EBNA titers. It is concluded that AT patients are often defective in their EBV-specific cell-mediated immune responses and with regard to their EBNA antibody levels. These defects are associated with a predominance of T cells reacting with OKT8 monoclonal antibody.
mesh_terms: D000293:Adolescent; D000914:Antibodies, Viral / Q000032:analysis; D000920:Antibody-Dependent Cell Cytotoxicity; D001260:Ataxia Telangiectasia / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D005260:Female; D004854:Herpesvirus 4, Human / Q000276:immunology*; D006801:Humans; D007111:Immunity, Cellular; D007694:Killer Cells, Natural / Q000276:immunology; D008214:Lymphocytes / Q000276:immunology; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000276:immunology
chemical_list: D000914:Antibodies, Viral