[Autoantibodies in juvenile rheumatoid arthritis. Clinical and serologic study].

Twenty five patients with juvenile rheumatoid arthritis were studied in order to define the frequency and kind of circulating autoantibodies in this entity, as well as, their relationship with the different disease subgroups and complications. Also the association of these autoantibodies with the activity stage of the illness was determined. There were 14 pauciarticular, 8 polyarticular and 3 systemic juvenile rheumatoid arthritis patients. Twelve have a flare of the disease and 13 were completely asymptomatic. Rheumatoid factor measured by the latex agglutination tests was positive in 6 children. These included 2 patients with pauciarticular disease, showing titers below 1:40 and 4 cases with polyarticular disease, showing titers above 1:320. One of these last patients developed and adult type rheumatoid arthritis during her evolution and was treated with D-penicillamine. The polyarticular but not the pauciarticular patients showed positive tests for rheumatoid factor by nephelometry. No definite association between these laboratory results and the activity of the disease was noted. Positive antinuclear antibodies by the indirect immunofluorescence test were found in 3 pauciarticular and one polyarticular patients. A predominant homogeneous staining was found with the mouse kidney substrate, whereas homogeneous and speckled patterns were noted with the homologous HEp-2 cells. One patient with persistent positive antinuclear antibodies revealed uveitis. Three of the 4 sera with positive antibodies by the indirect immunofluorescent test have also anti-nucleoprotein antibodies by the hemagglutination test with titers above 1:32.(ABSTRACT TRUNCATED AT 250 WORDS)