Pathogenesis, classification, and treatment of myelodysplastic syndromes (MDS)

Differentiation and hematopoietic-support of clonal cells in myelodysplastic syndromes

Studies were performed to obtain evidence of the differentiating and hematopoietic potential of marrow clone-original cells in patients with myelodysplastic syndromes (MDS). First, results of correlation analysis between bone marrow clonal cells and blast percentages for a total of 60 MDS showed that almost all cases had higher clonal (mean 50.1%) than blast proportion (mean 7.0%) (p < 0.001). In contrast, in 16 AML patients, mean clone/blasts disparity was nearly zero. Secondly, the amount of clone-original individual cells were defined in mature hematopoietic cells, mean 47.9% in segmented granulocytes, 47.1% in orthochromatic normoblasts and 37.8% in mature megakaryocytes. In addition, FISH examination showed approximately similar proportions of clonal cells in peripheral blood and marrow for all 22 tested cases (mean 39.1% in blood vs 49.8% in marrow). Moreover, the neutrophils in MDS peripheral blood oxidized dihydrorhodamine123 (DHR) nearly the same as neutrophils in a normal donor's circulation, while obviously poor function was observed in neutrophils from AML blood. Of note, research on clonality had an unexpected outcome as most of the typical morphological dysplastic cells possessed normal karyotypes. These findings lead to the proposal that the biological features of MDS clones are distinctive from those of AML clones.

Iron overload in myelodysplastic syndromes (MDS) - diagnosis, management, and response criteria: a proposal of the Austrian MDS platform

Transfusion-related morbidity is an emerging challenge in chronically transfused patients with low-risk myelodysplastic syndromes (MDS). In these patients, transfusion-induced iron overload may represent a leading medical problem. However, although iron-chelating drugs are available, little is known about optimal diagnostic tools, predisposing factors, and the optimal management of these patients. In the current article, we provide recommendations for the diagnosis, prevention and treatment of iron overload in MDS and propose treatment response criteria. Consensus criteria and resulting recommendations were discussed and formulated by members of the MDS platform of the Austrian Society of Haematology and Oncology in a series of meetings and conferences in 2006 and 2007. These recommendations should facilitate and assist in recognition of iron overload, selection of patients, timing of treatment, drug selection and the measurement of treatment responses.

Definitions and standards in the diagnosis and treatment of the myelodysplastic syndromes: Consensus statements and report from a working conference

The classification, scoring systems, and response criteria for myelodysplastic syndromes (MDS) have recently been updated and have become widely accepted. In addition, several new effective targeted drugs for patients with MDS have been developed. The current article provides a summary of updated and newly proposed markers, criteria, and standards in MDS, with special reference to the diagnostic interface and refinements in evaluations and scoring. Concerning the diagnostic interface, minimal diagnostic criteria for MDS are proposed, and for patients with unexplained cytopenia who do not fulfill these criteria, the term 'idiopathic cytopenia of uncertain significance' (ICUS) is suggested. In addition, new diagnostic and prognostic parameters, histopathologic and immunologic determinants, proposed refinements in scoring systems, and new therapeutic approaches are discussed. Respective algorithms and recommendations should facilitate diagnostic and prognostic evaluations in MDS, selection of patients for therapies, and the conduct of clinical trials.