ORIGINAL PAPER
Appreciation of value of bacteriological serodiagnostic in patients with undifferentiated arthritis

Serological methods, despite their undoubted weakness, are still basic and widely used methods in diagnosis of connective tissue diseases with suspected infectious aetiology.
We present a retrospective analysis of the results, done in years 2004-2006, of a search for the presence of anti-Yersinia enterocolitica serotype O3 autoantibodies in the sera of patients hospitalized and/or diagnosed in the Institute of Rheumatology. In the anti-Yersinia antibody assessment an immunoenzymatic method (ELISA) was applied in a group of about 3000 patients. Also the usefulness of these serological tests in the case of existing cross-reactivity between microorganisms such as (Salmonella enteritidis, Salmonella typhimurium, Borrelia burgdorferi and Chlamydia trachomatis) was studied.
The results demonstrated the relatively low diagnostic value of performed tests, because the difference in percentages of seropositivity of anti-Yersinia enterocolitica O3 (considered as pathogenic) in the group of tested patients and in the healthy population (average 5.5%) was insignificant.
Diagnostic value of these tests was additionally lowered by the co-appearance of antibodies directed at the above-mentioned microorganisms – belonging to separate taxa, possessing different transmission vectors and generating different clinical syndromes. In about 25% of sera seropositive for anti-Yersinia enterocolitica O3 antibodies also antibodies against at last one of the above-mentioned species was found. An in-depth analysis should be done by clinicians/rheumatologists of each seropositive case in relation to the clinical picture. Also an anamnestic interview seems necessary to the authors. It allows us to avoid excessively prolonged antibiotic therapy, which in many cases is unsuccessful and may be a cause of many side effects.