Altered responsiveness to mitogens in subgroups of patients with juvenile rheumatoid arthritis.

Thirty patients with juvenile rheumatoid arthritis (JRA) were compared to an age-matched control population with respect to lymphocyte transformation by the mitogens Concanavalin A, Phytohemagglutinin-P, Pokeweed and Lipopolysaccharide, as well as for the relative frequency of E-rosette and Ig-bearing cells in peripheral blood. The data were analysed according to sex, age of onset, mode of onset and disease activity. Lymphocytes from patients with a pauciarticular pattern of onset of JRA responded to mitogens in a similar fashion as normal volunteers, whereas lymphocytes from patients with both a polyarticular and Still's mode of onset had a diminished response to the mitogens. However, this reduction was noteworthy only during periods of disease activity; during periods of remission, lymphocytes from the patients responded similarly to lymphocytes from normals. In contrast to this reduction in mitogen stimulation in these subgroups of patients with JRA, all patients with JRA--irrespective of disease activity or mode of onset--were similar to controls with respect to the percentage of E-rosette and Ig-bearing cells. These alterations in mitogen responsiveness could not be attributed to therapy. Finally, the abnormalities of lymphocyte transformation in patients with polyarticular and Still's mode of onset represent secondary features of disease and are not due to a generalized predisposition or abnormality of cell mediated immunity.