EVIDENCE IN PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS OF THE PRESENCE OF ANTIBODIES AGAINST RNA-DEPENDENT DNA-POLYMERASE OF BABOON ENDOGENOUS VIRUS

Abstract

IgG 6 of 30 patients with systemic lupus erythematosus (SLE) strongly inhibited the activity of RNA-dependent DNA polymerase (RDPase) of baboon endogenous virus. M7, while IgG obtained from scleroderma patients, rheumatoid arthritis patients and normal subjects was less reactive. Experiments with anti-human IgG and with IgG F (ab'')2-bound immunoaffinity columns indicated that the inhibition of RDPase was antibody-mediated. The RDPase inhibiting activity of SLE IgG was considered not to be due to crossreactions of anti-nuclear antibodies including anti-DNA, anti-ribonucleoprotein, anti-Sm and anti-SS B antibodies. SLE IgG preferably inhibited the RDPase activity of baboon endogenous virus and a feline endogenous virus, RD114. Evidently, retrovirus(es) might be involved in SLE.