HLA-ANTIGENS AND SOME PATHOGENETIC ASPECTS OF REACTIVE ARTHRITIS

Aim. Investigation of associations of reactive arthritis (ReA) with hi stocompatibility antigens class I and II and determination of new appr oaches to assessment of association ReA with antigen HLA B27. Material s and methods. 118 ReA patients,vith associated intestinal and 82 ReA patients with associated urogenital infection were studied The infecti on was identified bacteriologically, with agglutination reaction, enzy me immunoassay, direct and indirect immunofluorescence, culturing. HLA -antigens were studied in lymphocytotoxic test: locus A. B and C in al l the patients, DR in 65 patients. Results. ReA triggers were intracel lularly parasite bacteria: facultative parasites in the enterocolitic variant (Yersinia, as a rule), obligate parasite in the urogenital (Ch lamidia, as a rule). HLA B27 antigen runs discovered in 77.5% of patie nts (RR 45.8), HLA DR1 - in 48.4% of patients (RR 3.3). in urogenital variant HLA B27 antigen occurred more frequently than in enterocolitic : 87.8% (RR 95.6) versus 70.3% (RR 31.5); p < 0.01). In HLA-B27-positi ve patients compared to HLA-B27-negative ones there were higher ESR (p < 0.001), leukocyte count (p < 0.05), concentrations of CRP and alpha -2-globulins (p < 0.001). Conclusion, In HLA-B27-subjects optimal cond itions exist for generalization of obligate parasites and favorable fo r production of facultative ones. The degree of association of ReA wit h HLA B27 antigens is dependent on adaptive features of microorganisms appearing in the process of evolution - obligaty and facultativeness of their internal parasitivity.