A five year prospective study of rheumatoid factor tests in juvenile rheumatoid arthritis

T IS RECOGNIZED that tests for rheumaI toid factors are less often positive in juvenile rheumatoid arthritis (JRA) than in the adult form of the disease. The explanation for this discrepancy is not completely clear. Those children who develop seropositivity may constitute a separate group of patients from the standpoint of diagnosis or prognosis. Ideally, to ascertain this, children with arthritis would be followed with serial rheumatoid ' factor tests well into adulthood. Data from this type of approach are not available at the present time. As a partial solution to this problem, a crosssectional group of patients with JRA of various ages and differing durations of disease activity has been examined. It is intended that such a composite view of the disease will approximate data that might have been obtained from the more desirable, longitudinal investigation.