ABSTRACT
Twenty-four biopsies of the synovial membrane, 8 biopsies of the cartilage and 8 samples of the synovial liquid from the knee joint were studied histologically, histochemically and by the immunofluorescent method. Proliferation, degeneration and desquamation of the synovial layer, localization of the inflammatory process in the superficial subsynovial layer, polynuclears in the inflammatory exudate, annular vascular sclerosis in the deep parts of the synovial villi are distinct features of psoriatic synovitis. The evidence for the involvement of humoral and cell immunity factors in the pathogenesis of the disease are obtained by means of immunological and immunofluorescent methods. On the basis of clinicomorphological data psoriatic arthritis is regarded as an independent nosological variety of the joint disease.