TRANSFUSION OF ALLOGENIC CORD BLOOD TO PATIENTS WITH MULTIPLE MYELOMA: SAFETY ANALYSIS AND INFLUENCE ON THE IMMUNOPHENOTYPE OF BLOOD LYMPHOCYTES IN THE EARLY PERIOD

Severe immune dysfunction occurs in the majority of cancer patients. One of the methods for overcoming immune disorders is transplantation of peripheral blood hematopoietic stem cells, both autologous and allogeneic, and transfusion of allogeneic natural killer cells (NK cells). Umbilical cord blood is a known source of not only hematopoietic stem cells (HSCs) but also NK cells, characterized by the rapid availability of blood samples from public cord blood banks. Purpose of the study: to analyze the safety of simultaneous transfusion of three allogeneic cord blood to patients with relapsed/refractory multiple myeloma  in the early period - 7 days after administration, and also to study the response of subpopulations of peripheral blood lymphocytes of patients to this intervention.  Material and methods: The pilot study included 10 patients (7 men and 3 women) with relapsed/refractory multiple myeloma  who had previously received more than 3 lines of therapy. The age of the patients was 59.4+3.4 years; all of them received a single transfusion of three allogeneic samples of umbilical cord blood with an average dose of leukocytes of 60.50+8.2x10⁸ (NK cells - 4.36+1.2x10⁸) per one patient. A total of 30 samples of umbilical cord blood, alloreactive for KIR receptors of the receptor-ligand type, were transfused. The selection of HSCs concentrates was carried out in the umbilical cord blood bank of the Dynasty Medical Center. Before transfusion of umbilical cord blood, patients received cyclophosphamide 5 mg/kg. After transfusion, patients received five subcutaneous injections of IL-2 (roncoleukin) in the amount of 1 million units per day. Observation at the time of assessment of preliminary results - 7 days after transfusion. Analysis of the immunophenotype of patients' lymphocytes was studied twice: on the day of transfusion before the start of the protocol and 7 days after transfusion of umbilical cord blood. Results: No early adverse reactions to transfusions were observed. Conclusion. Simultaneous transfusion of three allogeneic cord blood to patients with relapsed/refractory multiple myeloma  is a safe procedure, there are no adverse reactions or serious adverse events, as well as significant reactions and changes in the immunophenotype of patients' lymphocytes in the early observation period within 7 days after the intervention.