Analysis of interleukin-2 activity in patients with Behçet's disease. Ability of T cells to produce and respond to interleukin-2.

We examined interleukin-2 (IL-2) activity in patients with Behçet's disease. T cells from all patients with Behçet's disease were able to produce normal levels of IL-2 in response to phytohemagglutinin; however, responsiveness to IL-2 was impaired in their concanavalin A-activated lymphoblasts. This defect was due to decreased numbers of cells bearing IL-2 receptors in patients with early active disease; in patients with chronic active or with inactive disease, there was a decrease in density of IL-2 receptors on T cells bearing these receptors. Unresponsiveness of T cells to IL-2 may thus contribute to immunologic aberrations in Behçet's disease.