[Development of studies on problem of infectious arthritis at the Institute of RHeumatology, Russian Academy of Medical Sciences in 1970 to 1990].

The paper presents information on the studies on the elucidation of the etiopathogenetic role of Chlamydia and Yersinia infections in reactive arthritis, which have been made at the Institute in the past decades. Among them it mentions the first experiments and subsequent findings of detection of both Chlamydia and DNA in joint tissues in urogenic arthritis, those of identification of altered minor forms of this microbe in chronic types, which mimic in vitro persistent Chlamydia infection. The clinical experience gained by the Institute in treating Chlamydia-induced urogenic arthritis with high-dose antibiotics is reported. In addition to detailed studies of the clinical manifestations and outcomes of Yersinia-induced arthritis, long-term follow-ups have examined an association of clinical and serological manifestations with HLA B27 carriage; it is suggested that there is a partial similarity between this antigen and Yersinia antigens. Pronounced changes have been found in the mucosa of the intestine and its microflora in enterogenous reactive arthritis and a treatment with bifidum-containing drugs proposed. A variety of clinical and serological manifestations of Lyme borreliasis detected in the endemic areas of Russia is described. The specific features of rheumatological manifestations of this disease are comparable with those observed in the USA and Europe.