Decreased circulating thymus-derived cells with receptors for the Fc portion of immunoglobulin G in systemic lupus erythematosus.

Thymus-derived cells with receptors for the Fc portion of immunoglobulin G (Fcgamma+ T cells) have recently been found to have a suppressor function, a function that is decreased in systemic lupus erythematosus (SLE). Fcgamma+ T cells were found significantly diminished in 21 untreated SLE patients, particularly in the 7 patients who had active disease. Most Fcgamma+ T cells were separated with a subpopulation of T cells with low affinity for sheep erythrocytes. Decrease of this subpopulation was dependent on the decrease in Fcgamma+ T cells. Non-T cells with Fcgamma receptors were also diminished in SLE patients, but their decrease did not correlate with disease activity. The decrease in suppressor-cell function in SLE may be a result of loss, rather than of dysfunction, of the suppressor Fcgamma+ T cells.