Association between EBV Infection and SLE

New findings suggest that repeated or reactivated infection with Epstein Barr virus may play a role in the development of systemic lupus erythematosus.Dr Christine Parks and colleagues examined the seroprevalence of Epstein Barr virus (EBV) in 230 patients (144 African American and 86 white) with recently diagnosed systemic lupus erythematosus (SLE) and 276 age and sex matched controls.Participants were evaluated for antibodies to EBV and polymorphism in cytotoxic T lymphocyte-associated antigen 4 (CTLA-4), which the researchers identify as playing an important role in regulating T cell-mediated immunity, encompassing the first line of response to viral infections. The authors add that genetic variation in CTLA-4 has been associated with SLE.The results indicate seropositivity for EBV-IgA, but not IgM or IgG, was associated with SLE. However, in whites, its presence was only tied to a 1.6-fold increased risk of the SLE. Among patients with IgG antibodies to EBV, the risk of SLE rose as the titers increased. Once again, this association was most pronounced in African American subjects (pThe authors also report that allelic variation in the CTLA-4 gene promoter (-1661A/G) significantly modified the association between SLE and EBV-IgA (P = 0.03), with a stronger association among those with the -1661AA genotype.Reflecting on the groups findings, Dr. Parks' comments, "The racial difference in the association between EBV-IgA and SLE is intriguing, especially since African Americans have a higher risk of SLE, tend to develop the disease earlier, and often have a more severe course of disease.""One explanation could be that there are more opportunities for reinfection among African Americans, given the higher population prevalence of infection and likelihood of encountering and becoming infected with new viral strains," she suggested.The group conclude, "repeated or reactivated EBV infection, which results in increased EBV-IgA seroprevalence and higher IgG antibody titers, may be associated with SLE, and that the CTLA-4 genotype influences immune responsiveness to EBV in SLE patients".Reference...