LEVELS OF ANTI-STREP TOKINASE AND ANTI-MYCOBACTERIAL HEAT SHOCK PROTEIN 65 KILODALTON (ANTI-MHSP 65) ANTIBODIES IN PATIENTS WITH AUTOIMMUNE DISEASES

Bacterial and viral triggers are suspected agents in the initial etiology of autoimmune diseases. There are some studies on the etiology of autoimmune disorders which have focused on streptococcal infection and a possible relation with microbial heat shock proteins (hsp) which show significant homology with human heat shock proteins. In addition, some serotypes of streptococci cross-react with human hsp, namely 65kD hsp. Therefore, we have examined isotype specific antibody responses to streptokinase, the antigen released during infection with the common bacterium streptococcus, together with IgG responses to mycobacterium heat shock protein 65 (mhsp 65), a possible superantigen for autoimmune diseases. The levels of these antibodies were examined in patients with rheumatoid arthritis (RA), systemic lupus erythematosus (SLE), thyroiditis and Henoch Schonlein purpura (HSP) and a group of normal controls. Patients with RA showed a statistically significant elevation in levels oflgM anti-streptokinase antibodies compared to the control group (p<0.001). In Henoch Schonlein purpura patients, the levels of lgG and neutralising anti-streptokinase antibodies correlated with the levels of IgG anti-mhsp 65 (r= 0.56, p<0.09 and r= 0.57, p<0.08, respectively). According to these findings, we suggest that streptococcal infections may have an important role in the pathogenesis of rheumatoid arthritis and Henoch Schonlein purpura.