Biologic characteristics of patients with hypocellular myelodysplastic syndromes

Abstract Rates of proliferation and apoptosis as well as expression of tumor necrosis factor alpha (TNF-α), transforming growth factor beta (TGF-β) and the number of macrophages were measured in bone marrow (BM) biopsies of 33 patients who presented with hypocellular (cellularity r =0.583, P =0.003, n =24) as was apoptosis and the degree of anemia ( P =0.033, n =18). A subgroup of patients with abnormalities of chromosomes 5 or 7 had higher platelets ( P =0.026) and higher apoptosis ( P =0.038) when compared with the rest of the group. Eight patients had no evidence of apoptosis and almost no detectable TNF-α in their biopsies. We conclude that within the hypocellular variant of MDS, there may be two distinct sub-groups of patients, one who present with high cytokine-mediated intramedullary apoptosis and the other who may be better characterized as having a stem-cell failure defect since they showed no evidence of apoptosis.