[Circulation of intestinal infection in the families of patients with rheumatic diseases and the state of humoral immunity to enterobacterial antigens].

ELISA quantitation of antibodies to Klebsiella pneumonia, Proteus mirabilis, and Yersinia enterocolitica was conducted in 75 ankylosing spondylitis (AS), rheumatoid arthritis (RA), and systemic lupus erythematosus (SLE) probands and in 262 of their first-degree relatives. The control group comprised 28 healthy donors. Sixteen (64 per cent) AS probands (12 with B27+) and 26 (30.2 per cent) their relatives (14 with B27+) were found to have high titres of antibodies to Klebsiella pneumonia. In 18 (60 per cent) active RA probands and 27 (23.7 per cent) relatives, antibodies to Proteus mirabilis were found. The obtained results suggest the presence of genetic determinants of the increased immune response to various infectious agents, at least in the AS cases. The possibility of Enterobacteriaceae acting as polyclonal stimulators is not excluded.