ASSESSMENT OF THE FEATURES OF INNATE LYMPHOID CELLS IN PATIENTS WITH MULTIPLE MYELOMA

Multiple myeloma (MM) is a B-cell malignant tumor, the morphological substrate of which are plasma cells that produce monoclonal immunoglobulin. This is one of the most common tumors of lymphoid origin. It is known that during oncogenesis, the immune balance shifts towards suppression of the antitumor immune response. Innate lymphoid cells (ILC) are one of the key factors influencing the said balance. This study aimed to assess the features of ILC in MM patients. The peripheral blood levels of ILC1, ILC2, and ILC3, as well as the expression of HLA-DR on ILC 2, were measured with the help of flow cytometry. We found that MM patients (n = 14; 7 male and 7 female, mean age 59.2 +/- 2.08) had significantly more ILC2 in the peripheral blood, with the content thereof amounting to 63.1 +/- 4.51% among "helper" ILC, while in donors the proportion of ILC2 was 43.2 +/- 6.17% (p = 0.03). MM patients were also found to have a decreased amount of ILC2 that express HLA-DR: the proportion of such cells was only 2.2 +/- 1.53%, compared to 15.6 +/- 5.29% in donors (p = 0.003). The results of this study point to the shift in the immune balance and polarization of the immune response towards type 2 (T2), which may contribute to the suppression of the antitumor immune response.