Juvenile rheumatoid arthritis and spondyloarthropathies.

Further insight into the etiology and pathogenesis of juvenile rheumatoid arthritis (JRA) is presented in recent immunogenetic studies, particularly the allele associations of the pauciarticular pattern of disease. Evidence suggests that bacterial heat-shock proteins may be significant in the chronic inflammatory response in children with arthritis. Data on the role of complement activation and cytokines and their receptors also are presented. Coagulopathy in JRA may have more than one etiologic factor, including a viral agent, as may the disease itself. In the treatment of growth abnormalities in JRA, the neuroendocrine system, recombinant growth hormone, intravenous iron therapy, and nutritional supplementation are all areas of recent investigation. In outcome studies, ocular involvement and the presence of circulating IgM rheumatoid factor appear to be risk factors for disability. However, disease of less than 2 years' duration and absence of radiographic lesions likely predict good response to methotrexate therapy.