Treatment of patients with high-risk neuroblastoma (NB) is a complex challenge, and it is based on response to certain elements of therapy. The development and introduction of new treatment approaches, such as GD2-targeted immunotherapy (IT), leads to improved survival in this cohort of patients. The aim of the study was to retrospectively assess the effectiveness of therapy in patients with high-risk NB before the introduction of IT into clinical practice. We retrospectively analyzed the data of 151 NB patients stratified into a high-risk group who had received treatment in accordance with the modified NB2004 protocol of the German Society for Pediatric Oncology and Hematology (GPOH) at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology from 01.2012 to 12.2017. This study was approved by the Independent Ethics Committee and the Academic Council of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. All the study subjects (or their legal representatives) signed a voluntary informed consent form indicating their agreement to treatment and use of their data for research purposes. Overall survival (OS), event-free survival (EFS), and risk factors were analyzed in the patients with high-risk NB including those who had completed multimodal therapy with autologous hematopoietic stem cell transplantation and post-consolidation therapy with isotretinoin and had achieved a satisfactory response to induction therapy (complete response (CR), very good partial response (VGPR), partial response (PR)) (population of special interest). The main unfavorable prognostic clinical and molecular genetic factors affecting survival in the high-risk NB patients were older age, MYCN gene amplification, and stage 4 of the disease. The use of the modified GPOH NB2004 protocol resulted in a satisfactory response (CR/VGPR/PR) to the induction therapy in most patients: 124/151 (82.1 %). Surgery (other than primary tumor biopsy) led to improved survival, with no statistical difference between macroscopic radical surgery and macroscopic residual tumor. At the same time, radiation therapy (RT), as the second element of local control, had a significant impact on EFS in the group of the patients with stage 4 disease: the 3-year EFS was 39.4 % (95 % confidence interval (CI) 23.1–55.4) in the patients with RT versus 25.7 % (95 % CI 17.5–34.7) in the patients without RT (p = 0.0295). The introduction of a new high-dose TreoMel chemotherapy regimen did not result in worse survival rates but led to a decrease in transplant-related toxicity. The 5-year OS and 5-year EFS were 49.4 % (95 % CI 40.9–57.3 %) and 33.3 % (95 % CI 25.9–40.9) respectively for all the study subjects, and 81.6 % (95 % CI 70.3–88.9) and 55.1 % (95 % CI 43.1–65.5) respectively for the patients from the population of special interest. The analysis of the results of therapy in the high-risk NB patients who had received treatment at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology, yielded results comparable to those of the original GPOH NB2004 protocol. The patients with CR/VGPR/PR to the induction therapy who had completed the protocol treatment with autologous hematopoietic stem cell transplantation and isotretinoin post-consolidation therapy demonstrated higher 5-year EFS rates. However, there remains a need to develop more effective treatment regimens for high-risk NB.

Alpha-mannosidosis is a rare autosomal recessive hereditary disease from the group of lysosomal storage diseases with diverse clinical manifestations, the most typical of which are neurodegenerative process, hearing loss, skeletal deformities and immunodeficiency. The only radical treatment for this disease currently is allogeneic hematopoietic stem cell transplantation (allo-HSCT). Successfully performed allo-HSCT not only allows stoppage of the disease progression, but also leads to partial improvement in previously developed complications. The Article provides general information on the disease and demonstrates the Authors’ own experience of performing allo-HSCT in a patient with alpha-mannosidosis as well.

Medulloblastomas of the WNT molecular group (MB-WNT) represent the smallest group of MB and account for only 10 % of the total. This molecular group is characterized by a favorable prognosis. Given the aggressive treatment regimens for MB, reducing the intensity of therapy for prognostically favorable tumors seems justified. Purpose of the study – to demonstrate the results of treatment of children with MB-WNT and to determine the impact on survival of various prognostic factors. The study included 85 patients with MB-WNT under the age of 18 who received treatment and were followed up from 1993 to 2022. Median age at diagnosis was 10 years (min – 3, max – 17). All patients had classical MB. Metastatic spread of the tumor at the time of diagnosis was detected in 18 (21.2 %) patients, the presence of a residual tumor according to postoperative magnetic resonance imaging – in 32 (37.7 %). Somatic mutations in the TP53 gene were detected in 10 (7.1 %) patients, in the CTNNB1 gene – in 79 (92.9 %), in the APC gene – in 5 (5.9 %), chromosome 6 monosomy – in 76 (89.4 %) children. At the time of the analysis, 74 (87.1 %) patients were alive, 11 (12.9 %) patients died, a relapse was diagnosed in 6 (7.1 %) patients, of which 5 died from disease progression, 1 patient is alive in the second remission. One patient in long-term remission developed secondary meningioma 20 years after the diagnosis of MB. The 10-year progression-free survival (PFS) was 0.92. 5-year overall survival (OS) was 0.90, 10-year – 0.86. The median OS is 112 months. When analyzing the sample of patients with MB-WNT in our study, PFS and OS were statistically significantly higher in girls without metastatic tumor spread, with total resection of the tumor, stratified into the low-risk group, and in the absence of a somatic mutation in the TP53 gene in the tumor tissue. In multivariate analysis, PFS was influenced by the stage of the disease and the presence of a somatic mutation in the TP53 gene in the tumor tissue; on OS – only the presence of a somatic mutation in the TP53 gene in the tumor tissue.

Early complications of hematopoietic stem cell transplantation (HSCT) of vascular origin within the first 30-60 days after HSCT, which are resulting from endothelial injury, are an important cause of transplant-associated morbidity and mortality. Authors describe a case report serving as an example of several endothelial syndromes development with overlapping clinical features. Risk factors and therapy approaches of these complications are discussed.

Various conditioning regimes influence on sexual development and gonads function in children and adolescent after stem cell transplantation was studied. 45 patients were enrolled in the study: 23 patients with aplastic anemia (АА), who received non-myeloablative conditioning, and 22 patients with acute myeloid leukemia (AML) after myeloablative conditioning. Sexual development was estimated by Tanner classification, laboratory tests included gonadotropic hormones, sex steroids, antiMullerian hormone and inhibin B level detection. It has been shown that non-myeloablative conditioning does not influence sexual development in any patients. Extremely high frequency of gonads lesion in patients received myeloablative conditioning was registered: hypergonadotrophic hypogonadism in 8 from 12 girls with severe decrease of ovaries functional reserve in all patients; germinal epithelium lesion in 9 from 10 boys.

Allogeneic hematopoietic stem cell transplantation (allo-HSCT) is a common treatment for a large number of pediatric diseases. Treatment planning is based on a careful selection of patients and donors, taking into account factors contributing to a successful outcome. The aim of our study was to analyze the results of 10 years’ experience in allo-HSCT gained at the Department of Bone Marrow Transplantation of the Russian Children's Clinical Hospital of the N.I. Pirogov Russian National Research Medical University. We retrospectively analyzed 506 patients who had undergone their first allo-HSCTs between January 2010 and December 2020. The study was approved by the Independent Ethics Committee and the Scientific Council of the N.I. Pirogov Russian National Research Medical University of Ministry of Healthcare of the Russian Federation. We included 243 patients who had received allo-HSCT before December 2015 and 263 patients who had received allo-HSCT after January 2016. The gender distribution was 60.1% male (n = 304) and 39.9% female (n = 202). The median age was 7.13 years. Allo-HSCT recipients were divided into two groups: 236 children with non-malignant disease, 270 children with malignant disease. In the malignant group, 89 patients were in first complete remission (CR1), 92 were in second complete remission (CR2), and 20 were in third complete remission (CR3) and beyond; 63 patients had active disease (AD); 6 patients received no prior treatment. Two hundred and twenty patients underwent allo-HSCT from a fully matched family donor (MFD), 172 from a matched unrelated donor (MUD), 33 from a mismatched unrelated donor (MMUD) and 81 from a haploidentical (mismatched) family donor (MMFD). Two hundred and eighty-eight patients received bone marrow as a stem cell source, 208 received peripheral blood stem cells; 10 transplants were performed using umbilical cord blood stem cells. The 5-year overall survival (OS) in the entire cohort was 71.34 %. The 5-year OS in the patients who had undergone allo-HSCT between 2016 and 2020 was higher (p = 0.0014). After 2015, the rates of primary graft failure, the incidence of grade III–IV acute “graft-versus-host” disease (GVHD), and recurrence rates were significantly lower. No difference in the incidence of grade III–IV acute GVHD (p = 0.494) and OS rates (p = 0.138) was seen between different sources of hematopoietic stem cells in the patients who received an HLA-compatible transplant (MFD, MUD). Chronic GVHD was significantly dependent on the severity of acute GVHD and donor type. The 3-year OS rate for the patients in CR1, CR2, ≥ CR3, and AD was 84.4 %, 60.5 %, 56.8 %, and 46 % (p = 0.0034), respectively. The relapse rate of the patients in any remission was lower than of those in active disease (p = 0.015). The transplantation-related mortality in the first 100 days after allo-HSCT was 6.92% (n = 35). The patients who had undergone allo-HSCT after 2015 had lower rates of primary graft failure, a decreased incidence of severe GVHD, improved OS and relapse-free survival rates. The frequency of grade III–IV acute GVHD strongly correlated with HLA compatibility. Chronic GVHD was less frequent in MFD recipients. The risk of chronic GVHD increased with the severity of acute GVHD. The HLA mismatch between a donor and a recipient was associated with a decrease in OS. With each subsequent remission, the OS rate decreased. The risk of recurrence was higher in the patients transplanted in active disease. The results of this study can be used in clinical practice to plan therapy, choose an optimal donor, and develop strategies for the prevention and treatment of complications.

Protocol AML-MM-2000 treatment results of unfavorable prognostic group in children with primary acute myeloid leukemia (AML) in Russia and Belarus are presented. 105 children at the age from 2 weeks till 18 years (a median age — 10.8 years) are included in the study. In 91 patients (86.7%) hematological remission have reached, from them 34 patients (37.4%) are in the first continuous complete remission (CCR). 6-years overall survival (OS), event-free survival (EFS) and relapse-free survival (RFS) rate for all group of patients was 0.35 ±} 0.05; 0.32 ±} 0.04 and 0.43 ±} 0.05, respectively. Survival analysis of children with different cytogenetic anomalies has allowed to define two prognostic groups of patients: the intermediate prognosis, including patients with normal kariotype and t(9;11) which EFS and RFS rate was 40—50%, and unfavorable prognosis with EFS and RFS rate less than 40%. The efficiency analysis of three postremission therapy type (allogeneic and autological hematopoietic stem cells transplantation (HSCT) and chemotherapy (HT)) in intermediate and unfavorable prognostis groups was carried out. High efficiency of related HLA-identical HSCT in patients both intermediate and unfavorable prognostis groups have been shown. Autological HSCT is possible in intermediate prognosis patients with absence of HLA-identical siblings and in unfavorable prognosis patients with absence of HLA-identical unrelated donor.

Mutations in the MECOM gene (MDS1 and EVI1 complex locus) may be one of the causes of a rare combination of congenital radioulnar synostosis resulting in extremely limited forearm pronation and supination, and amegakaryocytic thrombocytopenia. The clinical spectrum of the disease can range from isolated radioulnar synostosis with or without hematologic manifestations to severe bone marrow failure without skeletal abnormalities. Other phenotypic manifestations include clinodactyly, brachydactyly, cardiac and renal malformations, presenile hearing loss, and B-cell deficiency. In view of the heterogeneity of phenotypic manifestations of the disease, the term “MECOM-associated syndrome” was proposed for all patients with mutations in the MECOM gene. Here we report 3 pediatric cases of MECOM-associated syndrome with different clinical manifestations, diagnostic approaches, therapeutic options, and outcomes. The patient’s parents agreed to use the information, including the child’s photo, in scientific research and publications.

Cytomegalovirus infection (CMV) is an extremely serious problem in patients after hematopoietic stem cells transplantation (HSCT). We have evaluated importance of major risk factors CMV development in patients after allogeneic HSCT (n = 168) from related (n = 56), unrelated (n = 90) or haploidentical donors (n = 22). Clinical importance of HSCT type as risk factors CMV development was shown; patients after unrelated or haploidentical HSCT had the worst prognosis. We also demonstrated that ≥ 2 grade acute GVHD statistically significant increase CMV reactivation probability after any types of HSCT. Comparison of infection reactivation frequency and event-free survival between subgroups of patients, received HSCT from CMV-positive and CMV-negative donors, absence of any differences was revealed. In the second group CMV infection was more severe. Preventive gancyclovir treatment has not shown efficacy and any influence on frequency of CMV reactivation.

BCG (Bacillus Calmette–Guerin) vaccine is widely used for the vaccination of newborns within the first few days of life to prevent mycobacterial infections. However, complications occurring after BCG vaccination in patients with primary immunodeficiencies (PIDs) can lead to serious consequences for their health and life. BCG vaccine-related complications occurring in patients with severe combined immunodeficiency (SCID) and chronic granulomatous disease (CGD) after hematopoietic stem cell transplantation (HSCT) constitute an important problem. The article presents a retrospective observational analysis of 45 patients with SCID and CGD who received BCG vaccination and underwent HSCT. In the post-transplant period, 33 (73.3%) patients had BCG-related complications, either localized or generalized. The presence of BCG vaccine-related complications in the pre-transplant period was a significant predictor of the development of post-transplant complications. The most severe and long-term BCG vaccine-related complications were observed in the patients with SCID: the median time to the resolution of symptoms of BCG infection was 30 days and 100 days in the CGD patients and the SCID patients, respectively (p< 0.001). The severity of BCG vaccine-related complications, the nature of the primary disease and the presence of pre-transplant BCG vaccine-related complications did not affect the overall survival (OS) of the patients: OS for the entire study group was 79.5 ± 6.6%. Non-compliance with antimycobacterial prophylaxis prior to HSCT resulted in severe infections in a number of patients. The treatment of BCG vaccine-related complications included a combination of several antimycobacterial agents, and anti-inflammatory drugs (such as glucocorticoids, interleukin-1 and 6 receptor antagonists) in cases of immune reconstitution inflammatory syndrome (n= 18). The only effective method of prophylaxis of BCG-related infections in patients with SCID and CGD in the pre- and post-transplant period is the exemption of newborns from BCG vaccination based on their family history. Uninterrupted antimycobacterial prophylaxis in vaccinated patients in the pre- and post-transplant period is also important. Furthermore, an effective uniform strategy for the prevention and treatment of BCG vaccine-related complications in PID patients both before and after HSCT is needed.

Here we report the results of long-term monitoring of children with malignant infantile osteopetrosis (MIOP) before and after a successful hematopoietic stem cell transplantation (HSCT). We present patient health data collected 3-6 years after the completion of treatment, including information on the children's physical and mental health and social adaptation. The study was approved by the Independent Ethics Committee and the Scientifi Council of the N.I. Pirogov Russian National Research Medical University of Ministry of Healthcare of the Russian Federation. HSCT is the only currently available radical treatment for MIOP. At the time of the treatment, all the patients exhibited severe visual impairment (descending optic atrophy), transfusiondependent bone marrow dysfunction, hepatosplenomegaly, signifiant skeletal abnormalities and growth retardation. In this study, we included 5 MIOP patients with successful transplantation who had been treated from 2014 to 2018. Four patients underwent HSCT from unrelated 10/10 HLA-identical donors and 1 patient received HSCT from a related 10/10 HLA-identical donor. The ratio of boys to girls was 2:3, the median age at the time of the transplantation was 7 (2–11) years. All the patients demonstrated full donor chimerism after HSCT. Hematopoietic recovery was achieved within the fist 150 days after HSCT. Radiological investigations showed gradual partial reduction of skeletal changes typical of MIOP. All the subjects demonstrated growth of the axial skeleton, facial bone remodeling and abatement of phenotypic features of the disease. The patients' vision remained the same as before HSCT. All the patients reported that their health and quality of life had improved after HSCT. The degree of visual impairment had a substantial impact on the quality of life and social rehabilitation of the patients. The second major factor affcting the quality of life was the development of chronic conditions after HSCT, namely, epilepsy and chronic “graft-versus-host” disease of the lung that require constant medical monitoring and limit rehabilitation potential. The patients' parents gave their consent to the use of their children's data, including photographs, for research purposes and in publications.

Umbilical cord blood (CB) has been used successfully as hematopoietic stem cells (HSCs) in adults and adults with malignant and non-malignant diseases in which there are indications for HSC transplantation (HSCT), and when an HLA-compatible related or unrelated donor is not available. CB, like any source of HSC, has certain advantages and disadvantages, which also determine the features of its use in transplantation. The article presents the experience of using CB as a source of HSC in pediatric patients at the Russian Children's Clinical Hospital (RCCH). Materials and methods of research: in a retrospective single-center continuous non-randomized uncontrolled open study includes 16 patients with various malignant diseases and 16 patients with non-malignant diseases, who underwent CB transplantation in the bone marrow transplantation department of the Russian Children's Clinical Hospital from 1997 to 2012. The peak of CB transplant activity occurred in the period from 2006 to 2010. The age of the patients at the time of the transplantation ranged from 6 months to 14 years. In 10 patients, a CB transplant from HLA-identical related donors was used, in 22 – from unrelated HLA-identical and HLA-incompatible for 2 or more antigens obtained from domestic CB banks. In addition to CB, six children were given bone marrow or peripheral blood stem cells from HLA-identical siblings as a transplant. The majority of patients (n=20) received one CB sample, 10 patients – 2 samples and two – 3. Results: implantation of the transplant was recorded in 27 children (84%), which 17 (53%) were alive, 10 (31%) died at different timesof post-transplant period. In 5 (16%) patients, implantation did not occur, of which one (3%) died, the cause of mortality in pediatric patients was a relapse of the underlying diseases. Acute graftversus-host reaction (GVHD) after CB transplantation was assessed in 27 (84%) patients of this study, among them 17 (63%) were diagnosed with acute GVHD stages I-II, 3 (11%) – stage III–IV (life-threatening form). Chronic GVHD was assessed in 18 (56%) patients included in the study, with 5 (28%) diagnosed with a limited form and 3 (17%) with an extensive form. Overall survival (OS) for the entire group of patients (n=32) was 58,3±8,8%, 5-year dormant survival rate (DSR) – 53±8.8%. OS in non-malignant diseases was higher (68%) than for malignant diseases (56%), but no statistically significant differences in OS were obtained in the two groups (p>0,05), as well as when comparing OS and DSR when using one or several samples of CB. Conclusion: CB remains available and acceptable source of stem cells for HSCT. At our center, the survival rates of patients after CB transplantation are comparable to those of international registries. The improvement of the method and the results of haploidentical SCT in recent years has led to a decrease in interest and transplantation activity (including in our center) using CB as a source of HSC. However, the unexplored antileukemic potential of CB stem cells, as well as a number of potential resources for improving and optimizing the use of this HSC source, may increase the chances of future CB transplantation.

Here we report the results of long-term monitoring of children with malignant infantile osteopetrosis (MIOP) before and after a successful hematopoietic stem cell transplantation (HSCT). We present patient health data collected 3-6 years after the completion of treatment, including information on the children's physical and mental health and social adaptation. The study was approved by the Independent Ethics Committee and the Scientifi Council of the N.I. Pirogov Russian National Research Medical University of Ministry of Healthcare of the Russian Federation. HSCT is the only currently available radical treatment for MIOP. At the time of the treatment, all the patients exhibited severe visual impairment (descending optic atrophy), transfusiondependent bone marrow dysfunction, hepatosplenomegaly, signifiant skeletal abnormalities and growth retardation. In this study, we included 5 MIOP patients with successful transplantation who had been treated from 2014 to 2018. Four patients underwent HSCT from unrelated 10/10 HLA-identical donors and 1 patient received HSCT from a related 10/10 HLA-identical donor. The ratio of boys to girls was 2:3, the median age at the time of the transplantation was 7 (2–11) years. All the patients demonstrated full donor chimerism after HSCT. Hematopoietic recovery was achieved within the fist 150 days after HSCT. Radiological investigations showed gradual partial reduction of skeletal changes typical of MIOP. All the subjects demonstrated growth of the axial skeleton, facial bone remodeling and abatement of phenotypic features of the disease. The patients' vision remained the same as before HSCT. All the patients reported that their health and quality of life had improved after HSCT. The degree of visual impairment had a substantial impact on the quality of life and social rehabilitation of the patients. The second major factor affcting the quality of life was the development of chronic conditions after HSCT, namely, epilepsy and chronic “graft-versus-host” disease of the lung that require constant medical monitoring and limit rehabilitation potential. The patients' parents gave their consent to the use of their children's data, including photographs, for research purposes and in publications.

Relevance. Infectious septic complications caused by polyresistant gram-negative micro-organisms are a pressing issue in the treatment of patients after polychemotherapy (PCT) and hematopoietic stem cell transplantation at the high risk of the fulminant current and high lethality against the background of hematopoesis aplasia. One of the therapeutic strategies of antimicrobial treatment is the systematic use of 0.5 % hydroxymethylquinoxaline dioxide (dioxidine) solution in the complex antibacterial therapy of patients with severe infectious-septic complications. The preparation has a bactericidal type of action, a wide spectrum of antibacterial activity. Experience in adult clinical practice has demonstrated the effectiveness of dioxidine in the treatment of the most severe forms of aerobic and anaerobic infection. Strict dose enforcement and injection technique to avoid the appearance of side effects. Data on the intravenous use of dioxin in children are presented in a limited number of scientific literature.The aim of the study was to demonstrate the efficacy of systemic use of hydroxymethylquinoxaline dioxide (0.5 % dioxidine solution) in children with infectious complications progressing against the background of aplasia of hematopoiesis caused by multidrug-resistant pathogens Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia.Materials and methods. 16 patients with a verified gram-negative infection were prescribed 0.5 % hydroxymethylquinoxaline dioxide solution as part of a combination antimicrobial therapy were included in the retrospective study. The median age of patients was 5 years (6 months – 16 years), 11 (69 %) were boys and 5 (31 %) girls.All children included in the study has infectious-septic complications at the PCT-induced hematopoietic aplasia, obtained according to the protocols of the main disease: severe combined immune deficiency (n = 2), idiopathic aplastic anaemia (n = 3), solid tumor (n = 2), acute myeloblastic leukemia (n = 7), acute lymphoblastic leukemia (n = 2). The main criterion for adding to the study was the existence at the least one site with a verified gram-negative infection (Pseudomonas aeruginosa, Klebsiella pneumoniae, Enterobacter cloacae, Stenotrophomonas maltophilia): bacteriemia (n = 11), oral mucosa (n = 6), ulcerative necrotic damage of perineum (n = 6), enterocolite (n = 6), infectionseptic compartments in the subcutaneous fat (n = 4), pleuropneumonia (n = 4), abscesses and inflammatory infiltration of the liver, spleen, pancreas, kidneys, lymph nodes (n = 1), infection of soft tissues in the area of the ventricular bypass with inflammatory changes of the brain membranes (n = 1).All patients received 0.5 % of the solution of dioxin by injection according of vital importance, as they had pathogens with confirmed laboratory resistance or clinical progression of the infectious process against the background of combined antibacterial therapy.Discussion. There is a complete control of fulminant developing infectious-septic processes caused by polyresistant micro-organisms against the background of hydroxymethylquinoxaline dioxide therapy in all 16 patients. The eradication of the pathogen, according to the microbiological study, has been confirmed in almost all observed patients, the efficacy of the drug has been preserved throughout the period of treatment, and the resistance of micro-organisms has not been observed. Strict adherence to the dosing and infusion technique of hydroxymethylquinoxaline dioxide has helped to achieve the full resolution of the infection process in all children without side-effects.Conclusion. On the basis of the experience presented, in immunocomputed patients of young age, 0.5 % dioxidine solution can be used as a necessary reserve preparation for the treatment of the most severe forms of infections of different localization, caused by polyresistant strains of gram-negative micro-organisms.

BCG (Bacillus Calmette–Guérin) vaccine is widely used for the vaccination of newborns within the first few days of life to prevent mycobacterial infections. However, complications occurring after BCG vaccination in patients with primary immunodeficiencies (PIDs) can lead to serious consequences for their health and life. BCG vaccine-related complications occurring in patients with severe combined immunodeficiency (SCID) and chronic granulomatous disease (CGD) after hematopoietic stem cell transplantation (HSCT) constitute an important problem. The article presents a retrospective observational analysis of 45 patients with SCID and CGD who received BCG vaccination and underwent HSCT. In the post-transplant period, 33 (73.3%) patients had BCG-related complications, either localized or generalized. The presence of BCG vaccine-related complications in the pre-transplant period was a significant predictor of the development of post-transplant complications. The most severe and long-term BCG vaccine-related complications were observed in the patients with SCID: the median time to the resolution of symptoms of BCG infection was 30 days and 100 days in the CGD patients and the SCID patients, respectively (p< 0.001). The severity of BCG vaccine-related complications, the nature of the primary disease and the presence of pre-transplant BCG vaccine-related complications did not affect the overall survival (OS) of the patients: OS for the entire study group was 79.5 ± 6.6%. Non-compliance with antimycobacterial prophylaxis prior to HSCT resulted in severe infections in a number of patients. The treatment of BCG vaccine-related complications included a combination of several antimycobacterial agents, and anti-inflammatory drugs (such as glucocorticoids, interleukin-1 and 6 receptor antagonists) in cases of immune reconstitution inflammatory syndrome (n= 18). The only effective method of prophylaxis of BCG-related infections in patients with SCID and CGD in the pre- and post-transplant period is the exemption of newborns from BCG vaccination based on their family history. Uninterrupted antimycobacterial prophylaxis in vaccinated patients in the pre- and post-transplant period is also important. Furthermore, an effective uniform strategy for the prevention and treatment of BCG vaccine-related complications in PID patients both before and after HSCT is needed.

Graft versus host” disease (GvHD) is one of the most frequent and severe complications of allogeneic hematopoietic stem cell transplantation (allo-HSCT). The optimal model of GvHD prophylaxis in allo-HSCT from alternative donors in children currently remains actual question. Materials and methods. The study was approved by the Independent Ethics Committee and the Scientific Council of the N.N. Blokhin National Medical Research Center of Oncology, Ministry of Healthcare of Russian Federation. Two hundred fifty six allo-HSCT were made during the period 2003–2019 from matched unrelated donors (MUD). Age median was 7.1 years old. The source of hematopoietic stem cells (HSCs) bone marrow – 76% (n = 194), peripheral blood stem cells – 24% (n = 62). GvHD prophylaxis included: tacrolimus (Tacro), cyclosporin A (CsA), methotrexate (Mtx), mycophenolate mofetil (MMF), in following combinations Tacro/Mtx (n = 98), Tacro/MMF (n = 102), tacro/Mtx + MMF (n = 3), CsA/Mtx (n = 24), CsA/Mtx + MMF (n = 12), CsA + MMF (n = 14). Median follow-up 8.9 years. GvHD prophylaxis regimen did not affect significantly the toxicity of therapy (toxicity: severe mucositis grade III–IV, nephrotoxicity, hepatotoxicity) (p = 0.4; p = 0.24; p = 0.62 respectively). In our study the rate of the overall survival (ОS) has significant differences in depending of the source of prevention GvHD. The using a combination of tacrolimus and cyclosporine with low doses of methotrexate had a positive effect on OS (p = 0.035) in patients of common non-malignant and malignant groups, as well as on the level of 2-year relapse-free survival in the group of children with malignant disorders (p = 0.671). In the general group the OS the worst results were achieved when MMF was included in the prophylaxis model. In this experience of treating of a large cohort of patients the choice of calcineurin inhibitors and methotrexate as the agent GvHD prophylaxis showed the efficacy and safety for non-manipulated MUD for both malignant and non-malignant diseases in children.

Relevance. Chronic granulomatous disease (CGD) belongs to the group of primary immunodeficiencies. Patients with CGD have an impaired quality of life, severe infections and inflammatory organ damage. Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment method for CGD. The authors of the article presented the experience of HSCT in patients with CGD in the Russian Children’s Clinical Hospital.Materials and methods. 20 (19 primary and 1 repeated) HSCT during the period from 2009 to 2020 were performed in nineteen patients with CGD. All patients had a long history of infections, three or more foci of chronic infection, 9 patients had a generalized BCG infection. Bone marrow (ВМ) from a related HLA-identical donor was the source of hematopoietic stem cells (HSC) for 4 (21 %) patients, peripheral blood stem cells (PBSC) for 2 (10.5 %). ВМ from a unrelated fully HLA-identical donor was performed in 9 (47.4 %) patients, PBSC – 2 (10.5 %). ВМ from a unrelated 9/10 HLA-compatible donor was performed in one (5.3 %) patient. In one case (5.3 %) the HSC source became PBSC from a unrelated 9/10 HLA-compatible donor after TcRαβ/CD19+ depletion. In 68.5 % (n = 13) cases the conditioning regimen included threosulfan, fludarabine, melphalan, and antithymocyte globulin. In 2 (10.5 %) patients, melphalan was excluded from the conditioning regimen; in 4 (21 %), it was replaced by thiotepa.Results. The overall survival (OS) was 88.9 ± 10.5 %, the event-free survival (EFS) was 88.1 ± 7.9 %, and there was no transplant mortality. Transplant rejections were observed in two patients who received HSC from a unrelated 9/10 HLA-compatible donor with a previous conditioning regimen that included only one alkylating agent. In 4 patients (21 %) there was a prolonged persistence of mixed chimerism after HSCT without clinical and laboratory signs of CGD. After successful transplantation all patients were cured of the infectious and inflammatory diseases characteristic of CGD.Conclusion. Results of HSCT in patients with CGD can be considered satisfactory, the OS and EFS are high. Failure of HSCT is associated with transplant rejection, which is most likely due to the donor and patient mismatch, as well as the use of conditioning modes with reduced intensity.

Hematopoietic stem cell transplantation (HSCT) in children is a high-tech field of medicine that combines the latest achievements of pediatric hematology, oncology, immunology, transfusiology, molecular biology and cell therapy. The success of HSCT is largely owing to the unique experience of international and national cooperation between transplant centers. A regular joint analysis of transplantation activity, focused on identifying trends and problems that require theoretical and practical solutions, is one of the most important components of such cooperation. The present work summarizes the experience of HSCT in all major pediatric centers in Russia for the period 2015–2018.

Hematopoietic stem cell transplantation (HSCT) in children is a high-tech field of medicine that combines the latest achievements of pediatric hematology, oncology, immunology, transfusiology, molecular biology and cell therapy. The success of HSCT is largely owing to the unique experience of international and national cooperation between transplant centers. A regular joint analysis of transplantation activity, focused on identifying trends and problems that require theoretical and practical solutions, is one of the most important components of such cooperation. The present work summarizes the experience of HSCT in all major pediatric centers in Russia for the period 2015–2018.