[Development of program therapy for patients with acute myeloid leukemia under the age of 60 years, based on the principles of differentiated effects].

AIM: To analyze the results of treatment in patients with acute myeloid leukemia (AML) within protocols AML-17 and modified AML-17 (mOML-17) as part of two consecutive pilot studies in order to develop the best treatment strategy for AML patients aged below 60 years. MATERIALS AND METHODS: The study included 89 AML patients who were aged below 60 years and received treatment within the AML-17 and mOML-17 protocols. Cytogenetic and molecular genetic studies were performed in all patients. The presence of mutations in the FLT3, NPM1, CEBPa genes was assessed by fragment analysis. 35 patients underwent a study for mutTP53, mutRUNX1 using next generation sequencing (NGS). The minimum residual population of tumor cells was evaluated by multicolor flow cytometry. Statistical analysis was performed using the procedures of the SAS 9.3 package. RESULTS: Complete remission (CR) was achieved in 89.7% of patients treated with intensive chemotherapy (CT) courses and in 52.4% of patients treated with low-dose CT courses. 8.8% of intensively treated patients were refractory to therapy, and 38% did not respond to low-dose exposure. The early mortality rate was 3%. The overall survival and disease-free 3-year survival for patients included in 2 consecutive studies was were 60% and 67%, respectively. The level of minimal residual disease (MRD) after the first course of induction CT was an important prognostic indicator. The three-year relapse-free survival for patients in whom CR was achieved after the first course of induction CT and in whom MRD was not detected (MRD-negative status was obtained) was 90% compared to 43% for patients who were MRD positive after the first course of induction CT (p=0.00001). CONCLUSION: The key factor that significantly affects the long-term results of therapy is the rate of MRD after the first course of induction CT.

[Multipotent mesenchymal stromal cells application for acute graft versus host disease treatment].

AIM: Analysis of the effectiveness of the MSCs aministration as the second- or third-line therapy of acute GVHD (aGVHD) resistant to glucocorticosteroid treatment. MATERIALS AND METHODS: The study included 35 patients who received MSCs obtained from the bone marrow of healthy donors as a treatment of steroid-resistant aGVHD. The clinical parameters of patients, MSCs cultural characteristics, the MSC expression profile for various genes including those involved in immunomodulation, expression of cells surface markers, the source of MSCs, as well as the frequency and number of MSC administrations were analyzed. RESULTS: Response to therapy was achieved in 74% of cases, a complete response was reached in 13 (37%) patients, partial response/clinical improvement was demonstrated in 13 (37%). This treatment was ineffective in 9 patients. The prediction of a group of patients with good response to MSC therapy turned to be impossible. The differences between the effective and ineffective for the GVHD treatment MSCs samples were found. The effective ones were characterized with a decreased total MSCs production and an increase in the main histocompatibility complex and PDL-1 antigens expression. CONCLUSION: These data allow to select optimal samples for aGVHD treatment that can improve clinical results. aGVHD treatment with MSCs has shown efficacy comparable to other treatment approaches. Given the low percentage of complications and the absence of significant adverse effects, MSC therapy seems to be one of the optimal approaches to the treatment of resistant forms of GVHD.