Detection of autoimmunity in early primary Epstein-Barr virus infection by Western blot analysis

The Epstein-Barr virus (EBV) represents a potentially important factor in the pathogenesis of certain autoimmune disorders such as systemic lupus erythematosus (SLE), and Sjögren's syndrome, probably through a molecular mimicry mechanism. Several studies have focused on the relationship between previous EBV infection and clinically overt connective tissue diseases (CTDs), while the aim of this study was to investigate the immunological alterations during the early phase of primary acute EBV infection by means of ENA Western blotting (WB) analysis. This technique is able to detect a wide spectrum of anti-ENA autoantibodies, potentially directed against diverse epitopes of the same antigen.

Sera from 54 subjects (F/M=24/30, mean age 17+/-6 SD years) with primary acute EBV infection were analysed using indirect immunofluorescence (IF) on Hep-2 cells for ANA, and both ELISA and WB for ENA.

Only 8 ANA+ and no ENA+ were found by means of IF and ELISA techniques, respectively; however, one or more ENA autoantibodies were detected in 24/54 (44%) sera using WB. The autoantibodies were no longer present at the second evaluation. Subjects with immunological alterations had not developed any significant clinical manifestations at a 5-year follow-up.

This study demonstrated the appearance of autoantibody production in a high proportion of individuals with primary acute EBV infection; interestingly, the observed serological subsets are quite similar to clinical SLE clusters. Moreover, the absence of immunological disorders during the follow-up reinforces the role of multiple genetic and/or environmental co-factors in the pathogenesis of CTDs.