It has been suggested that double negative (CD4-CD8-) (DN) and gamma/delta T cells may be involved in some autoimmune diseases. We investigated peripheral blood DN and gamma/delta T cell levels in patients with active juvenile rheumatoid arthritis (JRA).
DN and gamma/delta T cell levels were measured in 42 patients with active JRA and in 10 healthy controls comparable for age by an immunofluorescence double staining procedure.
All 3 JRA onset types had DN and gamma/delta T cell levels not significantly different from those of controls, although a wide scattering of data was present. No correlation was found between DN or gamma/delta T cell levels and erythrocyte sedimentation rate values or the number of active joints. When patients were divided according to treatment, we found that DN and gamma/delta T cell levels were significantly lower (p = 0.001, p = 0.02, respectively) in patients receiving methotrexate (MTX) than in patients not receiving MTX. The association of MTX treatment with a decrease in DN and gamma/delta T cell levels was also confirmed in a followup study of individual patients. Among patients not receiving MTX, patients with systemic JRA presented DN T cell levels significantly higher than those of controls. In 5 patients with pauciarticular JRA DN and gamma/delta T cell levels were higher in synovial fluid than in the peripheral blood.
We found an increase in peripheral blood DN T cell levels in systemic JRA; treatment with MTX appears to be associated with a decrease in DN and gamma/delta T cell levels.