[The comparative effectiveness of serological and microbiological studies in the etiological diagnosis of reactive arthritis].

The information content of serological and microbiological studies was studied and compared in 72 patients suffering from enterogenous reactive arthritis. A high level of antibodies to intestinal Yersinia was detected in 11.1% of the patients, positive coproculture in 8.3%. Only one patient demonstrated at a time a high level of antibodies and isolation of intestinal Yersinia coproculture. The causative agent could usually be isolated in patients with the symptoms of enterocolitis. It is assumed that among patients suffering from reactive arthritis there are at least two different groups: with positive coproculture and a low level of antibodies and with a high level of antibodies and negative coproculture. The indicated conditions can be regarded as different phases of the disease in the same patients and reflect the pathogenetic heterogeneity of the patients' group with reactive arthritis. Serological and microbiological tests are viewed as equivalent in etiological diagnosis of reactive arthritis. Emphasis is laid on the fact that microbiological tests are more successful in patients with the symptoms of concomitant enterocolitis.