Features of hematopoietic progenitor cell functioning in patients with myelodysplastic syndrome treated with lenalidomide

The stem cell pool is the primary site of malignant transformation, so studying progenitor cells in hematopoietic disorders is one of the most important ways to uncover the pathogenesis of malignant hemoblastoses. Myelodysplastic syndrome (MDS) is a hematologic disease characterized by genomic instability and heterogeneity. Treatment of MDS in the early stages of the disease (RAEB I) is limited to immunomodulators, one of which is lenalidomide. The drug is known to inhibit the proliferation of malignant cells by suppressing abnormal cloning and promoting apoptosis of Del(5q) cells. However, the extent of lenalidomide’s effect on the hematopoietic system in MDS has not yet been fully established. It is believed to enhance cellular immunity mediated by T cells and natural killer cells, and to inhibit the secretion of pro-inflammatory cytokines. The purpose of this study was to investigate the specific features of hematopoietic progenitor cell functioning under the influence of the immunomodulatory drug lenalidomide in patients with RAEB I. The study evaluated peripheral blood parameters and colony- and cluster-forming abilities of bone marrow hematopoietic progenitor cells cultured in semi-liquid agar. The study showed that the action of lenalidomide extends not only to the immune system, but also affects the closest descendants of the hematopoietic stem cells — hematopoietic progenitor cells — stimulating colony formation in 24% of bone marrow cultures and promoting the proliferation of all three blood lineages in the peripheral blood. These findings highlight the need to continue exploring therapeutic approaches for MDS that target early stages of hematopoiesis.