Selective reactivation of human herpesvirus 6 in patients with autoimmune connective tissue diseases

Viral infections have been associated with autoimmune connective tissue diseases. To evaluate whether active infection by Epstein–Barr virus (EBV), cytomegalovirus (CMV), human herpesvirus (HHV)‐6, ‐7, ‐8, as well as parvovirus B19 (B19V) occur in patients with autoimmune connective tissue diseases, viral DNA loads were assessed in paired samples of serum and peripheral blood mononuclear cells (PBMCs) of 115 patients affected by different disorders, including systemic sclerosis, systemic, and discoid lupus erythematosus, rheumatoid arthritis, and dermatomyositis. Two additional groups, patients affected by inflammatory diseases (n = 51) and healthy subjects (n = 58) were studied as controls. The titers of anti‐HHV‐6 and anti‐EBV antibodies were also evaluated. Cell‐free HHV‐6 serum viremia was detected in a significantly higher proportion of connective tissue diseases patients compared to controls (P