The overall goal of this project is to gain information about the etiopathogenesis of inflammatory joint diseases using reactive arthritis (specifically Yersinia arthritis) as a model. For this purpose the following groups of human subjects will be studied: patients with yersiniosis recovering from the infection without complications and those developing reactive arthritis, relatives of patients with yersiniosis, and healthy control persons; in addition patients in whom the disease turns out into a chronic one will be monitored. We will also determine and analyze the risk factors which make certain individuals susceptible to reactive arthritis and possibly change this disease into a chronic inflammatory joint process. Parameters and methods to be used include neutrophil chemotaxis and oxygen metabolism, qualitative and quantitative studies on IgA response, proliferative responses of lymphocytes to bacteria and bacterial antigens, assay of leukocyte migration inhibitory factors, studies on the persistence of Yersinia antigens in the synovia and synovial fluid, studies on the cross-reaction of bacterial antigens and tissue components by using monoclonal antibodies, and clinical monitoring.
