Galina Gennadjevna Solopova

The aim of the study was to conduct a retrospective analysis of the prevalence of markers for hepatitis B (HBV), hepatitis C (HCV), and HIV infection among patients in pediatric onco-hematology departments at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology (hereinafter referred to as the Center) between 2013 and 2025, and to compare these findings with general population prevalence rates for chronic HBV, chronic HCV, and HIV infection. Materials and methods. A retrospective analysis was performed on the detection rates of markers for HBV, HCV, and HIV infection among onco-hematology patients aged 0—19 years treated at the Center between 2013 and 2025. A comparative analysis was conducted against the prevalence of these infections in the country's pediatric population during the period from 2013 to 2024. Testing for HBV markers was performed in 17,816 patients, for HCV markers in 17,762 patients, and for HIV infection markers in 17,741 patients. HBV markers were identified via HBsAg and/or HBV DNA testing; HCV markers via anti-HCV and/or HCV RNA testing; and HIV infection via immunoblotting results. Results. The mean detection rates for HBV, HCV, and HIV infection markers were 1.1%, 0.1%, and 0.1%, respectively, of all patients tested. A comparison of the detection rates of HBV, HCV, and HIV markers among pediatric patients in onco-hematology units with the prevalence of these infections in the country's pediatric population revealed rates that were 6, 45, and 3 times higher ( p < 0.001), respectively. Conclusions. Pediatric patients in onco-hematology units constitute a high-risk group for HBV, HCV, and HIV infections.

Introduction. The rising incidence of mucormycosis among patients with hematologic and oncologic conditions has made it crucial to develop principles for the treatment of infectious complications as well as to assess the feasibility of allogeneic hematopoietic stem cell transplantation (HSCT) in this population. Aim: to analyze the specific aspects and safety of HSCT in children with mucormycosis. Materials and methods. This retrospective-prospective single-center study, conducted from 1 January 2013 to 31 March 2026 at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation, included HSCT recipients with a pre-transplant diagnosis of mucormycosis. The diagnostic work-up included computed tomography, magnetic resonance imaging, ultrasound, endoscopy, bronchoalveolar lavage, and biopsy of various organs and tissues depending on the site of involvement. From these specimens, slides were prepared in clearing solution supplemented with calcofluor white, a fluorescent agent. The slides were then examined under a fluorescence microscope using short-wavelength excitation at 400× magnification. Results. We analyzed treatment outcomes in 13 patients (median age: 11.7 years), 77% of whom had hematologic malignancies. At mucormycosis onset, pulmonary involvement was observed in 62% of the patients, paranasal sinus involvement in 54%; liver, spleen, and central nervous system involvement in 8%, and disseminated disease in 31%. Etiologic confirmation (77%) revealed Lichtheimia corymbifera (n = 2), Rhizomucor pusillus (n = 2), Rhizopus oryzae (n = 2), Rhizopus microsporus (n = 1), Mucor indicus (n = 1), and Mucor spp. (n = 2). All the patients received targeted antifungal therapy (amphotericin B, posaconazole, isavuconazole), with combination treatment used in 77% of cases. Surgical treatment was performed in 92% of the cases. Notably, radical resection significantly reduced the need for repeat surgeries (p = 0.02). Allogeneic HSCT was mostly performed using ex vivo αβ T-cell depletion (n = 11). At the time of transplantation, active infection was observed in 5 patients, partial response in 5 and complete response in 3. The median time to engraftment was 12 (10–35) days. Glucocorticoids for graft-versus-host disease were required in 3 patients. Mucormycosis was cured in 100% of cases. The median time to complete response was 82 days with early partial response (8 weeks) and 179 days with late response (p = 0.002). Infection status at HSCT did not affect the time to mucormycosis resolution. The overall survival was 59%, without any mucormycosis-associated deaths. Conclusion. The use of modern HSCT technologies (such as αβ T-cell depletion) in combination with aggressive antifungal treatment enables successful transplantation even in children with active mucormycosis.

Introduction. Allogeneic hematopoietic stem cell transplantation (allo-HSCT) using a TCRαβ/CD19 depletion platform is associated with a low incidence of graft-versus-host disease, however, delayed immune reconstitution increases the risk of opportunistic viral reactivation. Aim: to analyze the kinetics of pathogen-specific immune reconstitution and its impact on clinical outcomes of allo-HSCT. Materials and methods. We performed a retrospective analysis on a cohort of 265 children from the prospective database of the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology. All patients underwent their first allo-HSCT from a haploidentical donor with TCRαβ/CD19 depletion between September 2016 and March 2022. Pathogen-specific T-cell responses were assessed by IFN-γ ELISPOT assays (cutoff ≥10 SFC/3 × 10⁵ MNC) on days +30, +60, +90, +180, and at 1 year after allo-HSCT. Results. For cytomegalovirus (CMV), the proportion of ELISPOT-positive patients increased from 38.5 to 70% during the first year after allo-HSCT. For adenovirus, the proportion of ELISPOT-positive patients was 7% on day +30, 16% on day +90, and 38–49% from day +180 to 1 year. For Epstein–Barr virus, the proportion of ELISPOT-positive patients reached 22% at 1 year after allo-HSCT. On day +30, SFC counts for CMV showed the strongest correlation with CD3⁺CD8⁺ T cells; by 1 year, this association was no longer evident (R² = 0.005; p = 0.058). CMV ELISPOT positivity on day +30 correlated with CMV reactivation (57% vs 42%; p = 0.012), reflecting the effect of antigenic stimulation on T cell expansion. On day +60, ELISPOT positivity predicted a more favorable course of viremia, including a shorter duration of viremia (4 weeks vs 6 weeks; p = 0.023) and a lower peak viral load (9587 copies/mL vs 23 525 copies/mL; p = 0.029). The cumulative risk of transplant-related mortality was 3% (95% confidence interval 2–6); the trend toward lower transplant-related mortality in patients with ELISPOT positivity on day +30 did not reach statistical significance (1% vs 4%; p = 0.798). Conclusion. Therefore, reconstitution of pathogen-specific immunity after allo-HSCT is antigen-dependent. The presence of virus-specific T cells is associated with more effective control of viremia.

The aim of this study was to conduct an epidemiological analysis of hepatitis C infection in children with oncohematological diseases (OHD) using phylogenetic analysis of HCV nucleotide sequences and to analyze the causes and factors of HCV nosocomial transmission. Materials and methods. A retrospective analysis of HCV genetic isolates obtained from children with oncohematological diseases treated at the «Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology» (the Center) was conducted. The analysis included all children with HCV markers (anti-HCV and/or HCV RNA) identified between 2013 and 2025 during hospitalization and treatment at the Center—a total of 146 children. The children's ages ranged from 0 to 18 years, and from September 1, 2022, to 21 years. Samples were taken from the Center's bacteriology laboratory collection. Genotyping and phylogenetic analysis were performed at the Central Research Institute of Epidemiology of Rospotrebnadzor for 30 patient blood samples containing HCV RNA in quantities sufficient for analysis (at least 1000 IU/mL). To compare the distribution of HCV genotypes, the VGARus database data from 997 individuals was used. The core/E1 region of the HCV genome was sequenced and a phylogenetic analysis was performed. A Bayesian approach was used with the BEAST2 software package. The tree was visualized using FigTree. Results. In the structure of HCV genotypes isolated from children in the oncohematology departments, genotype 3a was predominant (77%), while 1b accounted for 23%. In contrast to the general population, where genotypes 3a and 1b circulate with equal frequency, the prevalence of genotype 3a among children with OHD indicates a greater involvement of this genotype in cases of nosocomial infection. Phylogenetic analysis revealed three common HCV clusters: 14 children with genotype 3a (13 children from the Amur Region and 1 child from the Altai Krai) and two common clusters with genotype 1b (2 patients each from the Kyrgyz Republic and Uzbekistan). The majority of HCV infection cases in children with OHD (60%) were nosocomial in origin. Cases of HCV infection in children from the Amur Region are associated with a long-standing chronic HCV epidemic in the oncohematology department of the Amur Regional Children's Clinical Hospital. No cases of infection have been identified at the Center. A patient from the Altai Krai region may have been infected at the Center in 2013-2014 during blood collection from a central venous catheter (CVC) due to improper hand sanitization, glove changing, aseptic technique, or work surface zoning. Standardization of procedures, implementation of aseptic non-touch technique (ANTT), training, and monitoring of staff knowledge and skills, widely implemented in the Center's work, have demonstrated high effectiveness, resulting in the absence of HCV transmission cases for over 10 years. Conclusion. Nosocomial HCV transmission in the OHD departments requires the widespread implementation of modern approaches to preventive and anti-epidemic measures, such as aseptic non-touch technique (ANTT), standardization of procedures, staff training, and knowledge and skills audits.

The aim of the study was to determine the incidence of occult hepatitis B in children with oncohematological diseases and primary immunodeficiency to evaluate the value of the anti-HBc marker for diagnosing occult hepatitis B. A retrospective analysis of the prevalence of hepatitis B virus (HBV) markers in children with oncohematological diseases was conducted. The study included 12,814 patients aged 18 years or younger (up to 21 years from September 1, 2022) treated at the «Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology» (hereinafter referred to as the Center) from 2018 to June 30, 2025. Patients were tested for the following infection markers: HBsAg (12,814 children), total anti-HBc (1,866 children), and HBV DNA (1,949 children). Anti-HBs antibodies were not measured. The prevalence of HBV infection in children with HBsAg or HBV DNA detection was 0.05 %. The prevalence of HBV markers HBsAg or HBV DNA or anti-HBc with combined detection was 1.0 %. Isolated anti-HBc was detected in 6.3 % of patients tested for this marker. No cases of seronegative occult hepatitis B were recorded. A statistically significant association was found between isolated anti-HBc and the administration of immunoglobulin preparations. The incidence of seronegative occult HBV (in the absence of HBsAg and anti-HBc) was 0 %. The presence of an isolated anti-HBc marker in the blood should not be considered seropositive for occult hepatitis B in immunocompromised children, as this marker may be transient in the presence of immunoglobulin replacement or immunomodulatory therapy.

Over the past two decades, the incidence of rare invasive mycoses, including fusariosis, has increased. Fusariosis remains diagnostically challenging and is associated with high mortality. Here, we present the results of a retrospective-prospective single-center study conducted between 01.01.2013 and 01.11.2025 at the Dmitry Rogachev National Medical Research Center of Pediatric Hematology, Oncology and Immunology of Ministry of Healthcare of the Russian Federation. The study aimed to evaluate the clinical characteristics, diagnostic performance, and treatment outcomes of immunocompromised children with fusariosis. It included 16 patients (10 males and 6 females), the median age was 11.5 years (range 2.5–16.0). Hematological malignancies were present in 70% of the cases; primary immunodeficiency, aplastic anemia, osteosarcoma, and systemic lupus erythematosus were less common. Fusariosis developed after chemotherapy (n = 9), hematopoietic stem cell transplantation (n = 4), or immunosuppressive therapy (n = 3). The major risk factors included severe neutropenia and corticosteroid use (87.5%). Disseminated disease occurred in 50% of the patients, localized fusariosis was diagnosed in 40% of the patients, and isolated fungemia was reported in one case. The most frequently affected sites were skin/soft tissues (50%), paranasal sinuses (50%), and lungs (43.75%). Parenchymal organs, bones and eyes were involved less often. The main pathogens were Fusarium solani (n = 6) and Fusarium proliferatum (n = 5), followed by Fusarium oxysporum, Fusarium verticilioides, and Fusarium petroliphilum. Seven patients developed invasive fungal co-infections with Aspergillus flavus (n = 4), Rhizopus spp. (n = 1), Scedosporium aurantiacum (n = 1) and Candida glabrata (n = 1) which was associated with increased mortality. First-line therapy included lipid formulations of amphotericin B (81%) and voriconazole (56%); combination therapy was used in 62.5% of the cases. Fourteen patients achieved a rapid partial response (the median time to response was 21 days), which correlated with favorable outcomes: all these patients were cured and had significantly higher overall survival. In the entire cohort, the 6-week survival was 81%, the overall survival was 69%. The study demonstrated the effectiveness of timely diagnosis and specific therapy for invasive fusariosis in the most vulnerable category of immunocompromised children.

Until the recovery of adaptive immunity, recipients of allogeneic hematopoietic stem cell transplantation (allo-HSCT) are at an increased risk of severe or even fatal infections. One such example is toxoplasmosis – a rare but an extremely dangerous complication in immunocompromised patients. The probability of Toxoplasma gondii reactivation after allo-HSCT is low and depends primarily on the serologic status of the donor and the recipient. Here, using as an example 4 clinical cases of cerebral toxoplasmosis in children after allo-HSCT, we want to emphasize the importance of timely and comprehensive testing, prevention and treatment of this complication in allo-HSCT patients.

(1) Background: Invasive fungal diseases (IFDs) represent significant challenges in clinical practice, particularly among immunocompromised individuals, leading to substantial morbidity and mortality. The present document aims to provide evidence-based consensus for the timely initiation of antifungal treatment, focusing on early empiric approaches among immunocompromised patients. (2) Methods: A multidisciplinary expert panel of nine healthcare professionals (HCPs) reviewed the literature, including guidelines and consensus reports (2013–2023; PubMed, Scopus). The panel defined appropriate empiric antifungal approaches for invasive candidiasis, aspergillosis, and mucormycosis among hematological and critically ill patients. Consensus was defined as ≥75% agreement. (3) Results: A total of 47 statements were included. The experts recommend that early targeted antifungal therapy is critical for high-risk patients with suspected IFDs. Empiric therapy may be initiated before definitive diagnosis, considering the local fungal prevalence and the patient’s risk category. Close monitoring is essential, and switching between antifungal classes may be necessary for patients who experience deterioration or side effects. The transition from intravenous to oral therapy depends on the specific infection, the availability of therapeutic drug monitoring, and the patient’s progress. (4) Conclusions: Implementing this targeted, early approach may improve the outcomes of vulnerable patients with IFDs.

Introduction. Pathogen reduction technologies in donor blood products have provided a preventive approach against a variety of hemotransmissive infections as well as prevention of donor leukocyte complications. However, while pathogen reduction in plasma and platelet concentrates is currently widespread, methods for reducing pathogens in red blood cell (RBC)-containing products are still being studied.Aim: to analyze the transfusion results of a pathogen-reduced RBC suspension in patients with various oncological and hematological diseases as well as defects of the immune system in order to prevent transfusion transmission of cytomegalovirus infection.Patients and methods. The results of transfusion therapy of a pathogen-reduced RBC suspension for the prevention of transfusion transmission of CMV infection in 27 patients who underwent transfusions during a long follow-up period are presented.Results. A total of 27 patients received 167 transfusions of pathogen-reduced RBC suspension. Transfusion efficacy, assessed by hemoglobin increase, was dependent on the transfusion volume per body weight, but was independent of the storage time of the RBC suspension over the measured interval. The transfusions were effective and tolerated without complications.Conclusion. The clinical use of pathogen-reduced RBC suspension is safe and provides sufficient clinical and laboratory efficacy.