Despite the achievements that have increased viability after the transplantation of allogeneic hematopoietic stem cells (aHSCT), chronic graft-versus-host disease (cGVHD) remains the main cause of late complications and post-transplant deaths. At the moment, therapy alternatives demonstrate limited effectiveness in steroid-refractory illness; in addition, we have no reliable data on the mechanism of this condition. The lack of drugs of choice for the treatment of GVHD underscores the significance of the design of new therapies. Improved understanding of the mechanism of chronic GVHD has secured new therapy goals, and organized diagnostic recommendations and the development of medical tests have ensured a general language and routes for studies in this field. These factors, combined with the rapid development of pharmacology, have helped speed up the search of medicines and medical studies regarding chronic GVHD. At present, we can hope for success in curing this formidable complication. This review summarizes the latest clinical developments in new treatments for chronic GVHD.

Hematopoietic stem cell transplantation (HSCT) is a treatment method for a number of severe malignant and non-tumor diseases. Autologous (auto) and allogeneic (allo) HSCT improves outcomes in patients with solid and hematological malignancies. The toxicity of conditioning regimens before HSCT is often a limiting factor for successful transplant outcomes. The most common manifestations of visceral and tissue toxicity are epithelial (dermatological and mucosal) toxicity, hepatotoxicity, and neurotoxicity. Reducing the incidence of toxic complications of preparative regimens preceding HSCT is the optimization of accompanying therapy, and and individualized selection of doses of chemotherapy. In our study, among 119 HSCT cases performed in 2021–2022, treosulfan-containing preparative regimens were used. Dermatological toxicity was diagnosed in 80.0 %, mucositis – in 100 %, hepatotoxicity – in 18.5 % of observations, no neurological toxicity was recorded.

There is no doubt that allogeneic hematopoietic stem cell transplantation (allo-HSCT) is one of the most effective treatments for many serious diseases. However, despite significant progress, allo-HSCT is still associated with a high rate of complications and mortality in the posttransplant period due to the toxicity of conditioning regimens, infectious and immune conditions. Acute complications such as endothelial injury, acute and chronic graft-versus-host disease (GVHD) remain the main causes of mortality after allo-HSCT. In our clinical case, we demonstrated an example of the development of such life-threatening complications as transplant-associated thrombotic microangiopathy and GVHD in a patient after repeated allo-HSCT, as well as the successful relief of these complications by modern therapeutic methods, including the introduction of closely related donor mesenchymal stem cells and the complement blocker eculizumab.

Germ cell tumors (GCTs) are a heterogeneous group of tumors that develop from pluripotent germ cells, diagnosed most often in infants, young children, adolescents and young adults, and are characterized by different localization, histological picture, clinical course and prognosis. Despite the fairly high efficiency of modern standard chemotherapy protocols for GCTs, the treatment of their relapses and refractory forms, which make up to 30–40 % of all GCTs and have an extremely unfavorable prognosis, is very difficult. Currently, there is no single strategy for the treatment of relapses and refractory forms of GCTs, however, the world and domestic literature presents data on the successful use of high-dose chemotherapy (HDCT) in such patients followed by autologous hematopoietic stem cell transplantation (auto-HSCT). To develop and optimize protocols for this therapy method, and therefore improve the treatment outcomes for patients with relapses and refractory forms of GCT, it is necessary to analyze a larger number of studies from various transplant centers working in this area. The article presents current literature data on the use of HDCT followed by auto-HSCT in patients with GCT, as well as a clinical case of successful 2 courses of HDCT with auto-HSCT in tandem mode in a child with a refractory form of GCT with subsequent maintenance of complete remission for 2 years.

Veno-occlusive liver disease (VOD), now more often referred to as “sinusoidal obstruction syndrome” (SOS), is a symptom complex that develops in the early stages after hematopoietic stem cell transplantation and some chemotherapy regimens due to the toxicity of a number of drugs used and accompanied by the following symptoms: hyperbilirubinemia, fluid retention, weight gain, and painful hepatomegaly. According to various sources, the incidence of SOS/VOD in patients with oncohematological profile ranges from 3 to 15 %. At present, the standard schemes for the prevention of this condition are not fully recommended. The article presents a brief review of the literature, representing international experience in the study and treatment of SOS/VOD.

Introduction. So far there has been no clear protocol on the treatment of bacterial infections in hematopoietic cancer patients undergoing polychemotherapy (PCT) and hematopoietic stem cell transplantation (HSCT). Guidelines available from antibiotic therapy panels such as EMBT, NCCN, ECIL, Sepsis-3 often fail to cover the entire spectrum of clinical risk factors of severe complications caused specifically by multiresistant Klebsiella pneumoniae.The aim of the study — is to showcase the clinical experience of demonstration of the experience of the Research Institute of Pediatric Oncology and Hematology at N.N. Blokhin Russian Cancer Research Center with respect to adjusting antibacterial therapy for the spectrum of microorganisms found in the patient before the onset of antitumor therapy, and for the multiresistant microorganism findings in patients with blood cancers and febrile neutropenia (FN) undergoing PCT and HSCT.Materials and methods. The study involved five patients undergoing either PCT or HSCT for hematopoietic cancers at Research Institute of Pediatric Oncology and Hematology in October 2019 — October 2020, multiresistant Klebsiella pneumonia colonies found in each case. Results. Five patients with hematopoietic cancers and induced bone marrow aplasia were found to have multiresistant Klebsiella pneumoniae colonies on top of post-PCT/HSCT immunosuppression. Given high risk of death, these patients need early antibacterial therapy with reserve antibiotics outside standard empirical antibacterial treatment protocols should they develop FN. The Center's practices have shown that baseline protocols are often inadequate to the severity of these patients' conditions in a certain timeframe.Conclusions. To sum up the Center's limited experience, the finding is that additional research is required into the factors of risk of severe multiresistant Klebsiella pneumoniae infections in patients undergoing PCT and HSCT; algorithms must be developed for the treatment of patients in such a critical condition.