Epstein–Barr virus and autoimmunity: the role of a latent viral infection in multiple sclerosis and systemic lupus erythematosus pathogenesis

Association of clinical and serological parameters of systemic lupus erythematosus patients with Epstein-Barr virus antibody profile

Epstein-Barr viral infection is one of the known environmental factors involved in development of Systemic Lupus Erythematous (SLE). Though not much is known about the exact role of Epstein-Barr virus (EBV) in SLE pathogenesis, the theory of switching of lytic and lysogenic cycles of EBV in memory B cells fits well with the periods of waning disease activity and intermittent flares in SLE patients. In this study, we investigate the association of EBV antibody profile with clinical and serological parameters in SLE. Eighty-seven clinically diagnosed SLE patients fulfilling the American College of Rheumatology (ACR) classification criteria and fifty healthy individuals were enrolled in this case control study. Anti-VCA IgM, anti-VCA IgG, and anti-EBNA IgG were detected by ELISA technique. Antibodies concentrations between two groups were compared using Mann-Whitney whereas the difference in categorical data was compared using Chi-square considering statistical significance at P < 0.05. This study demonstrated a significant increase in EBV VCA-IgG, VCA-IgM, and EBNA-IgG antibodies levels of SLE patients when compared to healthy controls (P < 0.05). High seroprevalence was seen in both the study groups for EBV VCA-IgG and EBNA-IgG antibodies when compared to VCA-IgM antibodies. A significant increase was noted in the anti-VCA-IgG levels with dsDNA autoantibody positivity (P < 0.05). Though there was no significant association between EBV antibody profile and clinical manifestations, 100% seropositivity for anti-VCA-IgG was seen in SLE patients with renal manifestations. Association of anti-VCA IgG levels with presence of anti-dsDNA antibodies suggests a possible role of EBV as an environmental trigger in pathogenesis of SLE.

Interaction of Intestinal Microorganisms with the Human Host in the Framework of Autoimmune Diseases

Autoimmune diseases, such as systemic lupus erythematosus (SLE), are caused by a complex interaction of environmental-, genetic-, and sex-related factors. Although SLE has traditionally been considered independent from the microbiota, recent work published during the last 5 years suggests a strong connection between SLE and the composition of our gut commensals as one of the main environmental factors linked to this disease. Preliminary data have evidenced that (i) interaction of certain microbial-derived molecules with specific cell receptors and (ii) the influence of certain commensal microorganisms over specific immune cell subsets plays an important role in the pathogenesis of SLE and SLE-like diseases. In addition, epigenetic changes driven by certain microbial groups have been recently proposed as an additional link between gut microbiota and SLE. As immune responses elicited against commensal bacteria are deeply dependent on the composition of the latter, and as microbial populations can be modified by dietary interventions, identifying the precise gut microorganisms responsible for worsening the SLE symptoms is of crucial importance for this and other SLE-related diseases, including antiphospholipid syndrome or lupus nephritis. In this minireview, the current knowledge on the relationships between microbes and SLE and SLE-related diseases is compiled and discussed.