The results of hematopoietic stem cell transplantation in patients with juvenile myelomonocytic leukemia at the Russian Children’s Clinical Hospital

Relevance. Allogeneic hematopoietic stem cell transplantation (HSCT) is the only effective treatment method for the majority of patients with juvenile myelomonocytic leukemia (JMML). The authors of the article presented the experience of conducting HSCT in patients with JMML in the Russian Children’s Clinical Hospital.Materials and methods. 55 HSCT for the period from 2003 to 2019 were performed in forty-two patients with JMML. 14 (33.3 %) patients from a related HLA-identical donor were given primary HSCT, 1 (2.4 %) from a related 9/10 HLA-compatible, 16 (38.1 %) – from unrelated HLA-identical, 6 (14.3 %) – from unrelated 9/10 HLA-compatible, 5 (11.9 %) – from haploidentical. The source of hematopoietic stem cells (HSC) in primary HSCT for 22 (52.4 %) patients was bone marrow (BM), for 13 (31.0 %) – peripheral blood stem cells (PBSC), for 4 (9.5 %) – cord blood (CB), for 3 (7.1 %) – BM in combination with CB. Twenty-two (52.4 %) patients received a myeloablative busulfan-containing conditioning regimen, 20 (47.6 %) – treosulfan-containing.Results. The overall survival (OS) of patients for the entire observation period was 53 ± 8.3 %; transplantation lethality (TL) – 21.2 ± 6.8 %, relapse-free survival (RFS) – 72.0 ± 7.7 %, event-free survival (EFS) – 49.4 ± 7.8 %. The factors negatively influencing the results of HSCT in patients with JMML were the progression of the underlying disease at the time of HSCT, incomplete compatibility of the HSC donor, the use of CB as a source of HSC.Conclusion. Indicators of OS, RFS, EFS patients with JMLL after HSCT are low. The reasons for treatment failure are TL, graft failure and relapse after transplantation. To improve the results of treatment of patients with JMML, careful selection of the donor and the source of HSC, the maximum possible reduction in the toxicity of conditioning regimens is necessary.