[The peripheral joint syndrome in ankylosing spondylitis--one of the variants of reactive arthritis].

In 75 patients with central (n = 37) and peripheral (n = 38) ankylosing spondylarthritis, EIA was used to detect serum antibodies to Klebsiella (IgG and IgA) and to the common enterobacterial antigen (CEBA) as compared to the level of the ESR, C-reactive protein and circulating immune complexes. Out of the 75 patients, 53 were examined for the intestinal microflora. Serum antibodies to Klebsiella were demonstrated more frequently in the peripheral form than in the central one, particularly in demonstrating Klebsiella coproculture. The presence of serum antibodies correlated with the disease activity. In the central form, enterobacteria without Klebsiella prevailed in the intestine. In both forms, antibodies to CEBA were demonstrated not so frequently (in 1/4 of the patients). In both forms, a large number of cases (74-80%) showed intestinal dysbacteriosis; in the peripheral form, however, it reached a greater degree. As to the central form, the etiological role of Klebsiella is not absolutely clear. It is more remarkable in the peripheral articular syndrome (reactive arthritis towards Klebsiella?) associated with ankylosing spondylarthritis.