Introduction. Due to the heterogeneity of the nature of myelodysplastic syndrome (MDS), the life expectancy and frequency of transformation into acute leukemia (AML) in patients with different subtypes of MDS is different. This became the impetus for the study of not only the factors that determine the length of overall survival of these patients, but also the identification of factors that influence the processes of transformation of the disease into AML. However, despite long-term research and significant improvements by scientists, the causes of the disease and the factors contributing to its progression are still not fully understood. Therefore, this problem requires permanent research and remains relevant in modern hematology.

Aim. Study of the expression level of TNF-α in blood serum of patients with MDS RANB I depending on the response to lenalidomide therapy.

Materials and methods. 39 patients with MDS RANB I of low and intermediate risk (according to the IPSS scale) treated with lenalidomide were examined, among whom there were 17 (43.9%) women and 22 (56.4%) men. The average age of the patients was 76 (range from 56 to 78). The diagnosis was established according to the criteria of the FAB classification (taking into account the changes proposed by the WHO in 2008) on the basis of clinical examination, the results of the examination of samples of peripheral blood and bone marrow aspirate (BM), trepanobioptate of BM, cytogenetic, immunophenotypic research of CM cells and on the basis of the exclusion of other diseases.

Results. The analysis of the data of 39 examined patients shows the presence of a relationship between the levels of TNF-α expression and the response to therapy in patients with MDS of RAEB I.

Conclusions. The conducted study can indicate the existence of a relationship between the content of TNF-α in blood serum and the response to therapy of patients with MDS who received treatment with lenalidomide. The results of the study provide a basis for the further search for new links in the pathogenesis of MDS.

Keywords: myelodysplastic syndrome, cytokines, TNF-α, blasts, bone marrow.