No evidence for gamma-interferon mediated haematopoietic inhibition by T cells in aplastic anaemia: an observation in the course of immunosuppressive therapy.

Two patients with aplastic anaemia were treated with immunosuppressive agents and peripheral blood T cells were cryopreserved serially. Inhibitory activity of T cells to autologous CFU-E, gamma-IFN production by T cells and T cell subpopulations were assayed after remission. Inhibitory activity to autologous CFU-E was not correlated with the numbers or ratios of T cell subpopulations. gamma-IFN production by T cells were within the normal range when inhibitory activity was found. In addition, gamma-IFN production increased after haematopoietic recovery. These findings suggest that gamma-IFN is not a soluble mediator of T cell-mediated haematopoietic inhibition in aplastic anaemia.