Hematological Characteristics of Patients with Myelodysplastic Syndromes in the Light of WHO 2008 Proposals.

Myelodysplastic syndromes have been reclassified by new WHO proposals published in 2008. So far, there are no data on haematological features of the newly composed subtypes. We analyzed 2063 patients with MDS diagnosed according to the WHO 2008 classification. Patients were characterized by their initial haematological features. We especially payed attention towards isolated cytopeniae with regard to the new classification of MDS subcategories. Analyses were performed by the use of the MDS registry Duesseldorf and included hemoglobin level, platelets, leukocytes and karyotype (available in 1091 patients) as well as age, gender, IPSS and WPSS at the time of diagnosis. All items have been assessed in our haematological laboratory and in the department of human genetics, respectively. The table shows characteristic features of MDS patients according to their WHO subtype. The patients’ median age did not differ substantially. There was a preponderance of females in the del(5q), RARS and RC group. Median hemoglobin level ranked lowest in the del(5q) and RAEB II group. Median thrombocyte, leukocyte as well as granulocyte level progressively decreased with more advanced WHO risk groups. Chromosomal aberrations were more frequent with increasing medullary blasts and degree of dysplasia. Likewise, patients with these characteristics were categorized into more advanced WPSS subtypes. About 90% of all patients were anemic, that is patients with a hemoglobin level of under 12 g/dl. Leukocytopenia as well as thrombocytopenia were more severe with increasing medullary blast counts. Of interest, 46% of RC patients showed a leukocytopenia (<4000/μl) and 37% had thrombocytopenia (<150.000/μl). 26% of this group showed an isolated anemia, whereas only 1–3% of the patients presented with an isolated leukocytopenia or thrombocytopenia. The majority of MDS patients presents with bicytopenia, regardless of subtypes. The degree of hematopoietic insufficiency is strongly correlated with the amount of medullary blasts, but as well with the degree of dysplasia in blood and marrow. An inclusion of the number of cytopenia into the WHO classification would lead to an alteration of subcategories and result in a shift towards a higher percentage of multilineage MDS.