ANTINUCLEAR ANTIBODIES ASSOCIATED WITH SCHISTOSOMIASIS AND ANTI-SCHISTOSOMAL ANTIBODIES ASSOCIATED WITH SLE

Various autoantibodies to nuclear antigens were detected by ELISA in p ooled sera of 15 ICR mice 9 weeks after infection with schistosoma. Th e binding of this serum with acute infection to cercarial extract was inhibited by prior incubation of the sera with DNA, polynucleotides an d cercarial extract. Sera from 9 BALB/c mice with experimentaly induce d lupus, reacted with cercarial extract. No binding was noted with nor mal mouse sera (NMS). Similarily, sera of SLE patients (N = 113) react ed with the parasite extracts in a higher incidence (14.2%) compared t o NHS (3.7%) (P < 0.05). Immunoblot analysis showed common features to SLE sera reacting with two antigenic ''groups''. The first are antige ns that also were recognized by sera of mice infected with schistosomi asis (60, 85, and 94 kDa cercarial proteins). The second group entaile d proteins that bound with SLE sera only (10-18 kDa, 29 kDa and 52 kDa ). It can be concluded that antinuclear autoantibodies can be found in sera of acute infected mice with schistosomiasis, while SLE sera may react with 3 schistosomal extracts in a higher incidence than NHS (P < 0.05). These results suggest an autoimmune response in schistosomiasi s. It is possible that a parasite infection (as bilharzia) may be one of the ''trigger'' mechanisms for SLE in a subject with the suitable i mmunogenetic and hormonal background.