[The role of TNF-alpha in myelodysplastic syndrome: immunoserologic and immunohistochemical studies]

TNF alpha is a highly active cytokine which plays an important role in the regulation of apoptotic cell death, a mechanism involved in the pathophysiology of myelodysplastic syndrome (MDS). In this study we investigated the expression of TNF alpha on the bone marrow trephine biopsies by immunohistochemical method and the TNF alpha production of peripheral blood mononuclear cells by ELISA method in 15 patients affected by MDS. Five of seven patients without excess of blasts showed high or intermediate TNF alpha expression in the bone marrow biopsies, whereas two patients with excess of blasts were negative and one had low expression. The five CMML patients revealed low or intermediate expression. The production of TNF alpha by the PBMC was analysed in 10 patients, four patients with RA and two with CMML produced higher level of TNF alpha which increased after stimulation with phorbol myristic acetate, but none of the RAEB patients revealed increase in TNF alpha production. In conclusion we suppose that increased TNF alpha expression and production by PBMC may be a further indirect evidence of the role of increased apoptosis in low risk MDS patients, in the course of progression the cytokine expression and production decreases.