A study of specificities of antinuclear antibodies in juvenile rheumatoid arthritis.

The sera from 77 children with juvenile rheumatoid arthritis were studied for the presence of antinuclear antibodies, rheumatoid factor, and for antibodies to seven well-characterized nuclear antigens which occur in specific rheumatic diseases of adults. These included: Sm, RNP, DNA, RNA, RAP, SS-A, and SS-B. Forty-nine percent of the sera from patients with JRA contained ANA. The most common pattern was speckled. The frequency of all other positive tests was too low (13%) to make correlations with disease states. However, a small group of girls with polyarticular and late-onset disease had a high incidence of RF or RAP. These two antibodies were not associated with each other as they are in adult RA.