A defect in immunoregulatory synovial fluid T cells in Behçet's syndrome.

Synovial fluid mononuclear cells from 5 patients with active Behçet's syndrome who were receiving no treatment were observed to have: decreased proportions of CD4+ and CD8+ cells, decreased proliferative responses of T cells in AMLR, poor capacity of non-T cells to stimulate in AMLR, decreased production of IL-2 upon PHA stimulation as compared both to their own peripheral blood mononuclear cells and to synovial fluid and peripheral blood mononuclear cells from 6 patients with RA and 6 patients with synovial effusions due to noninflammatory conditions. These findings provide further evidence of an immunoregulatory disturbance in Behçet's syndrome and indicate that synovial fluid, may be an important site where this derangement occurs in the active stage of the disease.