Most patients with myelodysplastic syndromes (MDS) present with single or multiple lineage cytopenias in peripheral blood despite a hypercellular bone marrow. Thrombocytopenia, attributable to ineffective platelet production by dysfunctional megakaryocytes, has been estimated to occur in 40-65% of patients. However, there are hardly any studies on the clinical relevance of low platelet counts in MDS.
We retrospectively analysed data from 2900 patients in the Duesseldorf MDS Registry who were diagnosed at our laboratory between 1982 and 2007.
At the time of diagnosis, 43% of the patients had a platelet count lower than 100 000/microL. Platelets were lower than 20 000/microL in 7% of the patients, especially in those with advanced stages of MDS, who showed a higher frequency of thrombocytopenia and platelet transfusion dependency. On multivariate analysis, platelet anisometry, hypocellularity of megakaryopoiesis, maturational defects of megakaryocytes and platelets <20 000/microL were independent variables showing a statistically significant correlation (P < 0.05) with clinical signs of bleeding. Platelets lower than 100 000/microL were associated with significantly shortened survival (P < 0.00005), because of an increased risk of progression to acute myeloid leukaemia (AML) (30% vs. 21%) (P < 0.02) and bleeding (16% vs. 8%) (P = 0.0005).
Thrombocytopenia is a strong predictor of short survival, with or without haemorrhagic complications.