Viral immune complexes in systemic lupus erythematosus: C-type viral complex deposition in skin.

Punch biopsies were examined by indirect immunofluorescence for immune complex deposits containing C-type viral antigen. Antisera specific for immunoglobulins and HEL-12 virus mediated fluorescence at the dermal-epidermal junction and in vessel walls of 16 of 16 biopsies involved skin from patients with systemic lupus erythematosus (SLE). Preimmune sera did not mediate fluorescence and gradient purified HEL-12 virus, simian sarcoma virus and baboon endogenous virus but not Rous sarcoma virus blocked the reaction of anti-HEL-12 virus serum with SLE tissue. Ten biopsies from uninvolved skin of the patients with SLE did not react with the antiviral serum, nor did tissue from 9 patients with discoid lupus erythematosus, psoriasis, bullous pemphigoid or normal skin. These data support the hypothesis that C-type viral immune complexes participate in the pathogenesis of SLE.