Respiratory viral infections are known causes of mortality after allogeneic hematopoietic stem cell transplantation (HSCT). Here, we report a unique case of a child with viral pneumonia caused by coinfection with human metapneumovirus (MPV), respiratory syncytial virus (RSV), and SARS‐CoV‐2 after HSCT. A 9‐year‐old girl with acute lymphoblastic leukemia underwent allogeneic HSCT from a matched, unrelated donor. During the post‐transplant period, in profound leukopenia (below 10 leukocytes/µL), she was diagnosed with SARS‐CoV‐2, MPV, and RSV pneumonia and was treated with ribavirin and chloroquine. Before leukocyte recovery, the girl became asymptomatic, and SARS‐CoV‐2 and RSV clearance was achieved. The shedding of SARS‐CoV‐2 stopped before immune system recovery, and one may hypothesize that the lack of an inflammatory response might have been a contributing factor to the mild clinical course. Post‐transplant care in HSCT recipients with COVID‐19 infection is feasible in regular transplant units, provided the patient does not present with respiratory failure. Early and repeated testing for SARS‐CoV‐2 in post‐transplant patients with concomitant infection mitigation strategies should be considered in children after HSCT who develop fever, respiratory symptoms, and perhaps gastrointestinal symptoms to control the spread of COVID‐19 both in patients and in healthcare workers in hospital environments. Training of staff and the availability of personal protective equipment are crucial for containing SARS‐CoV‐2 infection.

The use of home remedies for the treatment of moderately severe ailments is a common practice in the Polish population. Currently, the topic of the potential non-nutritional properties of human milk is attracting the attention of breastfeeding mothers. This study was aimed at understanding lactating women’s knowledge, attitudes, and practices of non-nutritional breast milk on mucous membranes. The study was conducted among lactating women, who filled out a questionnaire consisting of questions about their knowledge and experiences with non-nutritional use of human milk. Statistical calculations were conducted with chi-square test and c-Pearson coefficient. A total of 1187 women were acted on, whereby 768 of respondents claimed to have knowledge of the non-nutritional use of human milk on mucous membranes, whilst 404 of them claimed that they had used at least one method. Among the most frequently used methods were the treatment of rhinorrhea, lacrimal canaliculi obstruction, and conjunctivitis. A correlation between length of breastfeeding (p < 0.001) and knowledge of non-nutritional human milk usage in prophylaxis and treatment of mucous membrane inflammation was found. Breastfeeding duration (p < 0.001) and parity (p < 0.005) were correlated with the application of those methods in practice. Due to a high propensity to testing those methods, parents’ education in the field of possible risks and importance of medical consultations is necessary.

Severe aplastic anemia (SAA) is a bone marrow failure syndrome that can be treated with hematopoietic cell transplantation (HCT) or immunosuppressive (IS) therapy. A retrospective cohort of 56 children with SAA undergoing transplantation with fludarabine–cyclophosphamide–ATG-based conditioning (FluCyATG) was analyzed. The endpoints were overall survival (OS), event-free survival (EFS), cumulative incidence (CI) of graft versus host disease (GVHD) and CI of viral replication. Engraftment was achieved in 53/56 patients, and four patients died (two due to fungal infection, and two of neuroinfection). The median time to neutrophil engraftment was 14 days and to platelet engraftment was 16 days, and median donor chimerism was above 98%. The overall incidence of acute GVHD was 41.5%, and that of grade III-IV acute GVHD was 14.3%. Chronic GVHD was diagnosed in 14.2% of children. The probability of 2-year GVHD-free survival was 76.1%. In the univariate analysis, a higher dose of cyclophosphamide and previous IS therapy were significant risk factors for worse overall survival. Episodes of viral replication occurred in 33/56 (58.9%) patients, but did not influence OS. The main advantages of FluCyATG include early engraftment with a very high level of donor chimerism, high overall survival and a low risk of viral replication after HCT.

CD19-targeted CAR-T cell therapy has revolutionized the treatment of relapsed/refractory (r/r) pre-B acute lymphoblastic leukemia (ALL). However, it can be associated with acute toxicities related to immune activation, particularly cytokine release syndrome (CRS) and immune effector cell-associated neurotoxicity syndrome (ICANS). Cytokines released from activated immune cells play a key role in their pathophysiology. This study was a prospective analysis of proinflammatory proteins and cytokines in children treated with tisagenlecleucel. Serial measurements of C-reactive protein, fibrinogen, ferritin, IL-6, IL-8, IL-10, IFNγ, and TNFα were taken before treatment and on consecutive days after infusion. The incidence of CRS was 77.8%, and the incidence of ICANS was 11.1%. No CRS of grade ≥ 3 was observed. All complications occurred within 14 days following infusion. Higher biomarker concentrations were found in children with CRS grade ≥ 2. Their levels were correlated with disease burden and CAR-T cell dose. While cytokine release syndrome was common, most cases were mild, primarily due to low disease burden before lymphodepleting chemotherapy (LDC). ICANS occurred less frequently but exhibited various clinical courses. None of the toxicities were fatal. All of the analyzed biomarkers rose within 14 days after CAR-T infusion, with most reaching their maximum around the third day following the procedure.

The optimal bridging therapy before CAR-T cell infusion in pediatric relapsed or refractory B-cell precursor acute lymphoblastic leukemia (r/r BCP-ALL) still remains an open question. The administration of blinatumomab prior to CAR-T therapy is controversial since a potential loss of CD19+ target cells may negatively impact the activation, persistence, and, as a consequence, the efficacy of subsequently used CAR-T cells. Here, we report a single-center experience in seven children with chemorefractory BCP-ALL treated with blinatumomab before CAR-T cell therapy either to reduce disease burden before apheresis (six patients) or as a bridging therapy (two patients). All patients responded to blinatumomab except one. At the time of CAR-T cell infusion, all patients were in cytological complete remission (CR). Four patients had low positive PCR-MRD, and the remaining three were MRD-negative. All patients remained in CR at day +28 after CAR-T infusion, and six out of seven patients were MRD-negative. With a median follow-up of 497 days, four patients remain in CR and MRD-negative. Three children relapsed with CD19 negative disease: two of them died, and one, who previously did not respond to blinatumomab, was successfully rescued by stem cell transplant. To conclude, blinatumomab can effectively lower disease burden with fewer side effects than standard chemotherapeutics. Therefore, it may be a valid option for patients with high-disease burden prior to CAR-T cell therapy without clear evidence of compromising efficacy; however, further investigations are necessary.

Introduction: Posaconazole is recommended for prophylaxis in pediatric immunocompromised patients. Due to its variability in bioavailability and drug-to-drug interactions, EBMT recommends regimens based on therapeutic drug monitoring (TDM). Materials and methods: In total, 171 oncohematological pediatric patients on posaconazole prophylaxis were included. Full pharmacokinetic posaconazole profiles were assessed in 51 children. The efficacy and safety of posaconazole was evaluated by measuring the drug concentration, with dose modification attempted in patients with suboptimal results. The influence of modifying factors on the posaconazole plasma concentration (PPC) was investigated. Results: An insufficient PPC was the main issue, but no significant increase in prophylaxis failure was reported. The modification of the dosage resulted in the optimization of PPC in 50% of patients. No significant correlation between age, gender, diagnosis or the posaconazole dosage and the PPC was found. HCT, total parenteral nutrition and diarrhea were associated with a lower PPC. Hypoalbuminemia was related to both higher and lower PPC. The concomitant administration of specified drugs significantly impacted the PPC. Conclusions: TDM allows the identification of patients receiving non-optimal treatment and offers an opportunity to improve the efficacy and safety of the therapy. However, further research involving larger patient groups and longer observation periods are needed to determine the optimal dosing and target PPC in pediatric patients.