Infectious complications in patients with myelodysplastic syndromes: A review of the literature with emphasis on patients treated with 5-azacitidine.

Myelodysplastic Syndromes are oligo-clonal stem cell disorders that are associated with cytopenias in the peripheral blood. Major causes for morbidity and mortality in myelodysplastic syndromes (MDS) patients are infections mostly due to bacteria or fungi. Beside leucopenia per se in affected patients, function of white blood cells particularly that of neutrophils seems to be impaired. Here we summarize the available data on infections in MDS patients in general and particularly those treated with 5-azacitidine.

Phenotypic and functional characterization of neutrophils and monocytes from patients with myelodysplastic syndrome by flow cytometry.

Myelodysplastic syndrome (MDS) is a clonal stem cell disorder frequently associated with inefficient granulopoiesis showing dysplastic polymorphonuclear neutrophils (PMNs). To assess PMN functionality in MDS in a clinical routine setting, 30 MDS patients and ten healthy volunteers were analyzed for PMN and monocyte phenotype and function (degranulation, CD62L shedding, oxidative burst and phagocytosis) upon stimulation with lipopolysaccharide by multi-color flow cytometry (MCFC). Our data show a heterogeneous pattern for CD66, CD16 and CD64 expression on PMNs of MDS patients. CD62L shedding rate and CD66 degranulation were reduced. Interestingly, we detected correlations between the WHO adapted prognostic scoring system (WPSS) and CD16 expression on PMNs as well as the international prognostic scoring system (IPSS) and CD11b degranulation by MCFC, suggesting clinical relevance of MCFC based function testing. In conclusion, MCFC of myelodysplastic immunophenotypes and PMN functionality are applicable in clinical settings, but further prospective studies are needed to assess the practical clinical value of such analyses.