COMPARISON OF THE ANTI-LAMININ ANTIBODY-RESPONSE IN PATIENTS WITH SYSTEMIC LUPUS-ERYTHEMATOSUS (SLE) AND PARASITIC DISEASES (FILARIASIS)

In this study, we analyzed the presence of antibodies against the base ment membrane antigen laminin (LMN) in patients with systemic lupus er ythematosus (SLE), filariasis, and normal controls. By ELISA, 13.8% of SLE (12/87), 66.7% of parasitized patients (20/30), and two of the no rmal controls had these antibodies. IgG1 anti-LMN response was elevate d in all groups, whereas IgG2 and IgG3 were also elevated in parasitiz ed patients. The analysis of the IgG anti-laminin binding capacity in SLE and parasitized patients showed similar average antibody affinity. These antibodies did not react with fibronectin by a competition ELIS A. By Western blot, the anti-laminin antibodies could be demonstrated in parasitized patient sera but not in SLE sera. Moreover, the ability of these antibodies to bind to heat-treated LMN (100 degrees C for 4 min) was different. The study of the binding capacity with native or d enatured LMN by Western blot and dot-blot assays showed that the anti- LMN antibodies from parasitized patients were able to react with both native and denatured forms of LMN, whereas in SLE patients these antib odies were demonstrated only with native LMN. On the other hand, the r eactivity detected in the normal control sera seems to be different fr om the anti-LMN antibodies from SLE and parasitized patients, and prob ably reflects the existence of natural antibodies in these sera. The p resence of anti-LMN antibodies correlates significantly with the abili ty of inhibition of U937 cell adhesion to LMN-coated surfaces (P < 0.0 025). The difference of anti-laminin reactivity suggests that antibodi es produced following immunization with autoantigens or similar molecu les present in parasites have different specificities from those spont aneously produced by individuals with autoimmune diseases. (C) 1995 Ac ademic Press, Inc.