INCREASED PRODUCTION OF TUMOR-NECROSIS-FACTOR-ALPHA BY PERIPHERAL-BLOOD MONONUCLEAR-CELLS IN THE PATIENTS WITH APLASTIC-ANEMIA

The activity of tumor necrosis factor-alpha (TNF-alpha) in the supernatant of cultured peripheral blood mononuclear cells (PBMC) was measured in patients with aplastic anemia. It was significantly higher in patients with aplastic anemia than in normal controls, both when PBMC were unstimulated or when they were stimulated with PHA. Results from aplastic anemia patients were also significantly higher than patients who had received allogeneic bone marrow transplants. In aplastic anemia patients, the TNF-alpha value produced by PBMC upon stimulation and the platelet count were inversely correlated, as well those patients who had high TNF-alpha values tended to have lower hemoglobin and leukocyte values although this was not significant statistically. These results suggest that the increased production of TNF-alpha by PBMC plays a role in the severe suppression of hematopoiesis in aplastic anemia.