Effect of interleukin 10 on the hematopoietic progenitor cells from patients with aplastic anemia

The overproduction of cytokines with inhibitory effects on hematopoiesis is considered to play a role in the pathogenesis of aplastic anemia, While in terleukin 10 (IL-10) is a cytokine production inhibitory factor, the possib ility of immunosuppressive therapy using IL-10 for aplastic anemia has not been explored. In this study, therefore, we examined the effect of IL-10 on progenitor cells obtained from seven patients with severe aplastic anemia. Our study indicated that IL-10 dramatically enhanced the erythroid colony formation in a dose-dependent manner in two of the seven cases examined. Wh en we examined the concentration of cytokines in the culture supernatants o f unstimulated bone marrow cells, the spontaneous production of interferon- gamma (IPN-gamma) was observed in one of these two cases, and this producti on was completely inhibited by addition of IL-10, These findings suggested that IL-10 enhanced the erythroid colony formation by inhibiting the pathol ogical production of IFN-gamma in this case, This study provides an experim ental support for the clinical application of IL-10 in some patients with a plastic anemia.