Pelvic ultrasound and pubertal attainment in girls with sexual precocity: the pivotal role of uterine volume in predicting the timing of menarche.

Introduction: Among girls assessed for pubertal precocity, pelvic ultrasound (pUS) may represent a pivotal tool to predict the time expected to elapse between sonographic assessment and the onset of menarche (TUS-M). Accordingly, the present analysis is meant to define the statistical relationship between sonographic parameters and TUS-M, in order to identify the most reliable predictor of the timing of menarche. Methods: Retrospective, multicenter analysis. Girls assessed for sexual precocity and showing sonographic and clinical findings consistent with pubertal onset upon referral were considered eligible. Patients treated with GnRH analogues were excluded and only those who had subsequently achieved complete and spontaneous pubertal attainment and for whom the exact date of menarche was available were included. Overall, we enrolled 184 girls from five tertiary care Italian Centers. Results: The time elapsed (months) between baseline endocrine assessment and spontaneous achievement of menarche showed a negative statistically significant correlation (p<0.0001) with LH (r:-0.61), FSH (r:-0.59), estradiol (r:-0.52) and stimulated LH values (r:-0.58). Among pUS parameters, ovarian volume (r:-0.17 left, -0.30 right) and uterine body-to-cervix ratio (r:-0.18) poorly correlated with TUS-M, while uterine diameters (r:-0.61 longitudinal, -0.64 anteroposterior) and volume (r:-0.70) achieved a highly statistical significance (p<0.0001). Uterine volume (UV) showed a negative logarithmic relationship with TUS-M and represented the most reliable predictor of the timing of menarche in uni- and multivariable analyses (p <0.001). ROC analyses identified the UV thresholds that best predict the onset of menarche within 18, 12 and 6 months, respectively: 3.76, 6.02 and 8.80 ml. Conclusion: The logarithm of UV shows the best statistical performance in predicting the timing of menarche in girls assessed for pubertal precocity. Accordingly, we developed a user-friendly online application that provides clinicians with an estimation of the months expected to elapse before menarche, based on the UV recorded upon pUS.

An expert consensus on prevention, diagnosis, and management of hemorrhagic cystitis in pediatric hematopoietic cell transplantation, on behalf of the Infectious Disease and Hematopoietic Cell Transplant Working groups of Italian Pediatric Hematology Oncology Association (AIEOP).

The optimal management of hemorrhagic cystitis (HC) in hematopoietic stem cell transplantation (HCT) is debated, both for early onset HC (EOHC) secondary to chemotherapy toxicity and BK Polyomavirus (BKPyV)-related HC, due to the lack of controlled trials, particularly referred to pediatric setting. Actually, clinical practice is mainly based on guidelines of the European Conference on Infections in Leukemia, 6th edition, which considers both adult and pediatric populations but concludes that, despite much progress in understanding the pathogenesis, epidemiology, and risk factors, this complication still represents a disabling unmet clinical need with limited prophylactic and therapeutic options. Additionally, the Guidelines of the American Society of Clinical Oncology define the management of chemotherapeutic toxicity independently from the patients' population. A panel of experts belonging to the Hematopoietic Cell Transplant and Infectious Disease Working Group (WG) of Associazione Italiana di Emato-Oncologia Pediatrica (AIEOP) developed a consensus to define the best practices in prevention, diagnosis, and management of HC in pediatric HCT setting.

Anti-T-lymphocyte globulin exposure is associated with acute graft-versus-host disease and relapse in pediatric acute lymphoblastic leukemia patients undergoing hematopoietic stem cell transplantation: a multinational prospective study.

Anti-T-lymphocyte globulin (ATLG) is used in hematopoietic stem cell transplantation (HSCT) to prevent graft-versus-host disease (GVHD) and graft failure. To date, insight in ATLG pharmacokinetics and -dynamics (PK/PD) is limited, and population PK (POPPK) models are lacking. In this prospective study, we describe ATLG POPPK using NONMEM® and the impact of ATLG exposure on clinical outcome and immune reconstitution in a homogeneous cohort of pediatric acute lymphoblastic leukemia (ALL) patients transplanted with a matched unrelated donor and receiving uniform ATLG dosing. Based on 121 patients and 812 samples for POPPK analysis, a two-compartmental model with parallel linear and non-linear clearance and bodyweight as covariate, best described the ATLG concentration-time data. The level of ATLG exposure (day active ATLG <1 AU/mL, median 16 days post-HSCT) was strongly associated with aGVHD grade II-IV, with a lower incidence in patients with prolonged active ATLG exposure (≤day 16 50% vs. >day 16 8.2%; P<0.001). When stratified for remission state, patients transplanted in complete remission (CR) 2 or 3 with prolonged ATLG exposure had a higher relapse risk, while this effect was not seen in CR1 patients (P=0.010). High level ATLG exposure was associated with delayed CD4 T-cell recovery at 4 and 8 weeks post-HSCT, but not at 12 weeks, and overall and relapse-free survival were not influenced by CD4 recovery at 12 weeks post-HSCT. This study underlines the importance of individualized ATLG exposure with the use of model-informed precision dosing in order to optimize the HSCT outcome in pediatric ALL.

Haematopoietic stem cell transplantation after reduced intensity conditioning in children and adolescents with chronic myeloid leukaemia: A prospective multicentre trial of the I-BFM Study Group.

This prospective multicentre trial evaluated the safety and the efficacy of a thiotepa/melphalan-based reduced intensity conditioning (RIC) haematopoietic stem cell transplantation (HSCT) in children and adolescents with chronic myeloid leukaemia (CML) in chronic phase (CP). Thirty-two patients were transplanted from matched siblings or matched unrelated donors. In 22 patients, HSCT was performed due to insufficient molecular response or loss of response to first- or second-generation tyrosine kinase inhibitor (TKI), with pretransplant BCR::ABL1 transcripts ranging between 0.001% and 33%. The protocol included a BCR::ABL1-guided intervention with TKI retreatment in the first year and donor lymphocyte infusions (DLI) in the second-year post-transplant. All patients engrafted. The 1-year transplant-related mortality was 3% (confidence interval [CI]: 0%-6%). After a median follow-up of 6.3 years, 5-year overall survival and event-free survival are 97% (CI: 93%-100%) and 91% (CI: 79%-100%) respectively. The current 5-year leukaemia-free survival with BCR::ABL1 <0.01% is 97% (CI: 88%-100%) and the current TKI- and DLI-free survival is 95% (CI: 85%-100%). The incidence of chronic graft-versus-host disease (GvHD) was 32%, being severe in four patients (13%). At last follow-up, 31 patients are GvHD-free and have stopped immunosuppression. RIC HSCT following pretreatment with TKI is feasible and effective in children and adolescents with CP-CML with an excellent disease-free and TKI-free survival.

Safety and efficacy of narsoplimab in pediatric and adult patients with transplant-associated thrombotic microangiopathy: a real-world experience.

Transplant-associated thrombotic microangiopathy (TA-TMA) is a severe complication following hematopoietic stem cell transplantation (HSCT). No approved treatments are currently available. This study presents real-world data obtained with narsoplimab, a human immunoglobulin G4 monoclonal antibody that inhibits MASP-2, the effector enzyme of the lectin pathway of the complement system. Between January 2018 and August 2023, 20 (13 adult and 7 pediatric) patients diagnosed with TA-TMA received narsoplimab under an ongoing compassionate use program. The diagnosis was based on internationally defined criteria for pediatric and adult patients. Fifteen patients fulfilled the criteria recently established by an international consensus on TA-TMA. Nineteen patients exhibited high-risk characteristics. Thirteen patients (65%) responded to narsoplimab, achieving transfusion independence and significant clinical improvement. The one-hundred-day Overall Survival (OS) post-TA-TMA diagnosis was 70%, and 100% for responders. Narsoplimab proved to be effective and safe in the treatment of high-risk TA-TMA, with no increased infectious complications or other safety signals of concern across all age groups. The high response rates and the encouraging survival outcomes underscore the potential of narsoplimab as a valuable therapeutic option, particularly for high-risk cases.

Endocrine, auxological and metabolic profile in children and adolescents with Down syndrome: from infancy to the first steps into adult life.

Down syndrome (DS) is the most common chromosomal disorder worldwide. Along with intellectual disability, endocrine disorders represent a remarkable share of the morbidities experienced by children, adolescents and young adults with DS. Auxological parameters are plotted on syndrome-specific charts, as growth rates are reduced compared to healthy age- and gender-matched peers. Furthermore, children with DS are at increased risk for thyroid dysfunctions, diabetes mellitus, osteopenia and obesity compared to general population. Additionally, male individuals with DS often show infertility, while women tend to experience menopause at an overall younger age than healthy controls. Given the recent outstanding improvements in the care of severe DS-related comorbidities, infant mortality has dramatically decreased, with a current average life expectancy exceeding 60 years. Accordingly, the awareness of the specificities of DS in this field is pivotal to timely detect endocrine dysfunctions and to undertake a prompt dedicated treatment. Notably, best practices for the screening and monitoring of pediatric endocrine disorders in DS are still controversial. In addition, specific guidelines for the management of metabolic issues along the challenging period of transitioning from pediatric to adult health care are lacking. By performing a review of published literature, we highlighted the issues specifically involving children and adolescent with DS, aiming at providing clinicians with a detailed up-to-date overview of the endocrine, metabolic and auxological disorders in this selected population, with an additional focus on the management of patients in the critical phase of the transitioning from childhood to adult care.

The CAR T-cell race: The rules of the game.

The management of paediatric patients with refractory acute lymphoblastic leukaemia eligible for the CAR T cell product tisagenlecleucel involves multiple decision points between the process of patient referral to product infusion. How to address the individual patient's circumstances, optimize apheresis yields and, above all, plan the best bridging chemotherapy is clearly detailed in these comprehensive and practical recommendations by Kumar Mishra and colleagues. Commentary on: Mishra et al. Practice guideline: Preparation for CAR T-cell therapy in children and young adults with B-acute lymphoblastic leukaemia. Br J Haematol 2024;204:1687-1696.

Outcomes of allogeneic haematopoietic cell transplantation for myelofibrosis in children and adolescents: the retrospective study of the EBMT Paediatric Diseases WP.

This retrospective study evaluated 35 children (median age 5.2 years; range 0.4-18) with myelofibrosis (MF), including 33 with primary myelofibrosis and 2 with secondary myelofibrosis transplanted from matched sibling donor (MSD) (n = 17) or non-MSD (n = 18) between 2000 and 2022. Conditioning was usually chemotherapy-based (n = 33) and myeloablative (n = 32). Fifteen patients received bone marrow (BM), 14 haematopoietic cells (HC) from peripheral blood (PB), and 6 from cord blood (CB). Day +100 acute GvHD II-IV incidence was significantly lower after MSD-haematopoietic cell transplantation (MSD-HCT) than after non-MSD-HCT [18.8% (4.3-41.1) vs 58.8% (31-78.6); p = 0.01]. Six-year non-relapse mortality (NRM) was 18% (7.1-32.8), relapse incidence was 15.9% (5.6-30.9), progression-free survival (PFS) was 66.1% (47-79.7), GvHD-free relapse-free survival was 50% (30.6-66.7), and overall survival (OS) was 71.1% (51.4-84). Six-year PFS and OS were significantly higher after BM transplantation compared to HCT from other sources [85.1% (52.3-96.1) vs 50.8% (26.3-71), p = 0.03, and 90.9% (50.8-98.7) vs 54% (28.1-74.2), p = 0.01, respectively], whereas NRM was significantly lower [0% vs 32% (12.3-53.9); p = 0.02]. This first multicentre study on outcomes of allogeneic HCT in children with myelofibrosis proves feasibility and curative effect of transplantation in these children, suggests that bone marrow transplantation is associated with better outcomes, and indicates the need for further studies.

Long-Term Complications after Allogeneic Hematopoietic Stem Cell Transplantation with Treosulfan- or Busulfan-Based Conditioning in Pediatric Patients with Acute Leukemia or Myelodysplastic Syndrome: Results of an Associazione Italiana Ematologia Oncologia Pediatrica Retrospective Study.

Patients undergoing hematopoietic stem cell transplantation (HSCT) for hematologic malignancies during childhood have an increased risk of developing long-term sequelae that are in part attributable to the conditioning regimen. The present study aimed to assess the occurrence of long-term toxicities in a population of children who underwent HSCT for hematologic malignancies using either treosulfan or busulfan in the conditioning regimen. The cumulative incidences of growth impairment, altered gonadal function, altered thyroid function, cataracts, secondary malignant neoplasia, and altered pulmonary function were evaluated retrospectively by univariable and multivariable analyses in a population of 521 pediatric patients with acute leukemias or myelodysplastic syndromes treated in 20 Italian transplant centers affiliated with the Associazione Italiana Ematologia ed Oncologia Pediatrica (AIEOP). The median duration of follow-up for the entire study population was 7.1 years (range, 1 to 16 years). Overall, a larger proportion of patients given busulfan developed long-term toxicities compared to patients treated with treosulfan (34% versus 20%; P = .01). In univariable analysis, gonadal toxicity developed in 10% of patients who received treosulfan (95% confidence interval [CI], 3% to 15%), compared with 38% (95% CI, 24% to 39%) of busulfan-treated patients (P = .02), and this finding was confirmed by multivariable analysis (relative risk, .51; 95% CI, .34 to .76; P = .0009). We did not find any statistically significant associations between the occurrence of other long-term toxicities and the use of either busulfan or treosulfan. This study provides evidence that the use of treosulfan is correlated with a reduced incidence of gonadal toxicity in children undergoing HSCT for hematologic malignancies.

Matched unrelated donor transplantation versus haploidentical transplantation with post-transplant cyclophosphamide in children with acute myeloid leukemia: a PDWP-EBMT study.

In children with acute myeloid leukemia (AML) who lack a human leukocyte antigen (HLA) identical sibling, the donor can be replaced with an HLA-matched unrelated donor (MUD) or a haploidentical donor (haplo). We compared outcomes of patients <18 years with AML in first and second complete remission (CR1 and CR2) undergoing a hematopoietic stem cell transplantation (HCT) either with a MUD with anti-thymocyte globulin (ATG) (N=420) or a haplo HCT with post-transplant cyclophosphamide (PT-CY) (N=96) after a myeloablative conditioning regimen (MAC) between 2011 and 2021, reported to the European Society for Blood and Marrow Transplantation. A matched pair analysis was performed to adjust for differences among groups. The final analysis was performed on 253 MUD and 95 haplo-HCT. In the matched cohort, median age at HCT was 11.2 and 10 years and median year of HCT was 2017 and 2018, in MUD and haplo-HCT recipients, respectively. The risk of grade III-IV acute graft-versus-host disease (aGVHD) was significantly higher in the haplo group (hazard ratio [HR]=2.33, 95% confidence interval [CI]: 1.18-4.58; P=0.01). No significant differences were found in 2 years overall survival (OS; 78.4% vs. 71.5%; HR=1.39, 95% CI: 0.84-2.31; P=0.19), leukemia-free survival (LFS; 72.7% vs. 69.5%; HR=1.22, 95% CI: 0.76-1.95; P=0.41), CI of relapse (RI; 19.3% vs. 19.5%; HR=1.14, 95% CI: 0.62-2.08; P=0.68) non-relapse-mortality (NRM; 8% vs. 11%; HR=1.39, 95% CI: 0.66-2.93; P=0.39) and graft-versus-host free relapse-free survival (GRFS; 60.7% vs. 54.5%, HR=1.38, 95% CI: 0.95-2.02; P=0.09) after MUD and haplo-HCT respectively. Our study suggests that haplo-HCT with PT-CY is a suitable option to transplant children with AML lacking a matched related donor.

Low rate of nonrelapse mortality in under-4-year-olds with ALL given chemotherapeutic conditioning for HSCT: a phase 3 FORUM study.

ABSTRACT: Allogeneic hematopoietic stem cell transplantation (HSCT) is highly effective for treating pediatric high-risk or relapsed acute lymphoblastic leukemia (ALL). For young children, total body irradiation (TBI) is associated with severe late sequelae. In the FORUM study (NCT01949129), we assessed safety, event-free survival (EFS), and overall survival (OS) of 2 TBI-free conditioning regimens in children aged <4 years with ALL. Patients received fludarabine (Flu), thiotepa (Thio), and either busulfan (Bu) or treosulfan (Treo) before HSCT. From 2013 to 2021, 191 children received transplantation and were observed for ≥6 months (median follow-up: 3 years). The 3-year OS was 0.63 (95% confidence interval [95% CI], 0.52-0.72) and 0.76 (95% CI, 0.64-0.84) for Flu/Thio/Bu and Flu/Thio/Treo (P = .075), respectively. Three-year EFS was 0.52 (95% CI, 0.41-0.61) and 0.51 (95% CI, 0.39-0.62), respectively (P = .794). Cumulative incidence of nonrelapse mortality (NRM) and relapse at 3 years were 0.06 (95% CI, 0.02-0.12) vs 0.03 (95% CI: <0.01-0.09) (P = .406) and 0.42 (95% CI, 0.31-0.52) vs 0.45 (95% CI, 0.34-0.56) (P = .920), respectively. Grade >1 acute graft-versus-host disease (GVHD) occurred in 29% of patients receiving Flu/Thio/Bu and 17% of those receiving Flu/Thio/Treo (P = .049), whereas grade 3/4 occurred in 10% and 9%, respectively (P = .813). The 3-year incidence of chronic GVHD was 0.07 (95% CI, 0.03-0.13) vs 0.05 (95% CI, 0.02-0.11), respectively (P = .518). In conclusion, both chemotherapeutic conditioning regimens were well tolerated and NRM was low. However, relapse was the major cause of treatment failure. This trial was registered at www.clinicaltrials.gov as #NCT01949129.

Busulfan-fludarabine- or treosulfan-fludarabine-based conditioning before allogeneic HSCT from matched sibling donors in paediatric patients with sickle cell disease: A study on behalf of the EBMT Paediatric Diseases and Inborn Errors Working Parties.

How important is choice of conditioning regimen in allogeneic haematopoietic stem cell transplantation (HSCT) for sickle cell disease (SCD)? We compared HSCT outcomes by conditioning regimen in paediatric patients with SCD from the EBMT registry. In 2010-2020, 251 patients aged <18 years underwent a first matched sibling donor (MSD) HSCT with conditioning based on busulfan-fludarabine (bu-flu; n = 89) or treosulfan-fludarabine (treo-flu; n = 162). In the bu-flu and treo-flu groups, 51.7% and 99.4% of patients, respectively, received thiotepa. Median follow-up was 2.7 years. Two-year overall survival (OS) was 98.7% (95% confidence interval [CI]: 90.9-99.8) with bu-flu and 99.3% (95% CI: 95.2-99.9) with treo-flu (p = 0.63). Grade III-IV acute graft-versus-host disease (GVHD) at 100 days was 2.4% (95% CI: 0.4-7.5) and 0.6% (0.1%-3.2%) for bu-flu and treo-flu respectively (p = 0.25). The 2-year incidence of extensive chronic GVHD was 1.5% (95% CI: 0.1-7.3) with bu-flu and 8.0% (95% CI: 4.1-13.3) with treo-flu (p = 0.057). These multinational data confirm the excellent curative capacity of MSD HSCT with myeloablative conditioning. Both conditioning regimens yielded excellent OS, low rates of acute and chronic GVHD, and low rates of graft failure.

A novel flow-cytometric based method to assess post-HSCT donor chimerism exploiting RNA hybridization.

Analysis of donor-recipient chimerism after hematopoietic stem cell transplantation (HSCT) is of pivotal importance for patient's clinical management, especially in the context of mixed chimerism. Patients are routinely monitored for chimerism in sorted subsets of peripheral blood cells. However, measurement of chimerism in sorted immune cell subsets is technically challenging and time consuming. We here propose a novel, flow cytometry-based approach to detect donor cell chimerism in sex-mismatched HSCT. We exploit RNA PrimeFlow™ system, based on RNA hybridization, to detect mRNA from a lysine demethylase encoded by Y chromosome, KDM5D. This approach allows to distinguish male and female derived cells with around 1% sensitivity. The procedure can be coupled with multiparametric immunophenotyping to assess chimerism in specific immune cell subsets without the need for prior FACS-sorting. We apply this method to a cohort of HSCT patients (n = 10) and we show that it is consistent with standard PCR-based method. We also show that different T lymphocyte subsets display variable degrees of donor chimerism, especially in CD8+ T cell compartment where we observe an enrichment for recipient chimerism in central memory T cells. This method can be exploited to advance current knowledge on immune reconstitution focusing on specific subsets avoiding prior FACS-sorting.

Pubertal attainment and Leydig cell function following pediatric hematopoietic stem cell transplantation: a three-decade longitudinal assessment.

Introduction: Impaired testosterone secretion is a frequent sequela following hematopoietic stem cell transplantation (HSCT) in pediatrics, but long-term longitudinal trendlines of clinical and biochemical findings are still scanty. Methods: Monocentric, retrospective analysis. Male patients transplanted <18 years between 1992 and 2021, surviving ≥2 years after HSCT and showing, upon enrollment, clinical and biochemical signs consistent with pubertal onset and progression were included. Clinical and biochemical data collected every 6-12 months were recorded. Results: Of 130 patients enrolled, 56% were prepubertal, while 44% were peri-/postpubertal upon HSCT. Overall, 44% showed spontaneous progression into puberty and normal gonadal profile, while the remaining experienced pubertal arrest (1%), isolated increase of FSH (19%), compensated (23%) or overt (13%) hypergonadotropic hypogonadism. Post-pubertal testicular volume (TV) was statistically smaller among patients still pre-pubertal upon HSCT (p 0.049), whereas no differences were recorded in adult testosterone levels. LH and testosterone levels showed a specular trend between 20 and 30 years, as a progressive decrease in sexual steroids was associated with a compensatory increase of the luteinizing hormone. A variable degree of gonadal dysfunction was reported in 85%, 51%, 32% and 0% of patients following total body irradiation- (TBI), busulfan-, cyclophosphamide- and treosulfan-based regimens, respectively. TBI and busulfan cohorts were associated with the lowest probability of gonadal event-free course (p<0.0001), while it achieved 100% following treosulfan. A statistically greater gonadotoxicity was detected after busulfan than treosulfan (p 0.024). Chemo-only regimens were associated with statistically larger TV (p <0.001), higher testosterone (p 0.008) and lower gonadotropin levels (p <0.001) than TBI. Accordingly, the latter was associated with a 2-fold increase in the risk of gonadal failure compared to busulfan (OR 2.34, CI 1.08-8.40), whereas being pre-pubertal upon HSCT was associated with a reduced risk (OR 0.15, CI 0.08-0.30). Conclusions: a) patients pre-pubertal upon HSCT showed a reduced risk of testicular endocrine dysfunction, despite smaller adult TV; b) patients showed downwards trend in testosterone levels after full pubertal attainment, despite a compensatory increase in LH; c) treosulfan was associated to a statistically lower occurrence of hypogonadism than busulfan, with a trend towards larger TV, higher testosterone levels and lower gonadotropins.

Immune effector cell-associated hematotoxicity: EHA/EBMT consensus grading and best practice recommendations.

Hematological toxicity is the most common adverse event after chimeric antigen receptor (CAR) T-cell therapy. Cytopenias can be profound and long-lasting and can predispose for severe infectious complications. In a recent worldwide survey, we demonstrated that there remains considerable heterogeneity in regard to current practice patterns. Here, we sought to build consensus on the grading and management of immune effector cell-associated hematotoxicity (ICAHT) after CAR T-cell therapy. For this purpose, a joint effort between the European Society for Blood and Marrow Transplantation (EBMT) and the European Hematology Association (EHA) involved an international panel of 36 CAR T-cell experts who met in a series of virtual conferences, culminating in a 2-day meeting in Lille, France. On the basis of these deliberations, best practice recommendations were developed. For the grading of ICAHT, a classification system based on depth and duration of neutropenia was developed for early (day 0-30) and late (after day +30) cytopenia. Detailed recommendations on risk factors, available preinfusion scoring systems (eg, CAR-HEMATOTOX score), and diagnostic workup are provided. A further section focuses on identifying hemophagocytosis in the context of severe hematotoxicity. Finally, we review current evidence and provide consensus recommendations for the management of ICAHT, including growth factor support, anti-infectious prophylaxis, transfusions, autologous hematopoietic stem cell boost, and allogeneic hematopoietic cell transplantation. In conclusion, we propose ICAHT as a novel toxicity category after immune effector cell therapy, provide a framework for its grading, review literature on risk factors, and outline expert recommendations for the diagnostic workup and short- and long-term management.

Long-Term Host Immune Modulation Following Tisagenlecleucel Administration in Patients with Diffuse Large B-Cell Lymphoma and B-Lineage Acute Lymphoblastic Leukemia.

Background: Chimeric antigen receptor (CAR)-T cells represent a potentially curative strategy for patients with relapsed or refractory (R/R) B-cell malignancies. To elucidate a possible host immune activation following CAR-T-cell infusion, we investigated the effects of tisagenlecleucel administration on the patients' immune populations in 25 patients with R/R diffuse large B-cell lymphoma (DLBCL) and B-lineage acute lymphoblastic leukemia (B-ALL). Methods: The modulation of CAR-T cells over time, the numeric changes, as well as the cytokine production capability of different lymphocyte populations and circulating cytokine levels, were analyzed. Results: Our results confirmed the ability of tisagenlecleucel to control the disease, with an overall response observed in 84.6% of DLBCL and in 91.7% of B-ALL patients at 1-month post-infusion, and showed that most patients who subsequently relapsed could undergo further treatment. Interestingly, we could document a significant increase in CD3+, CD4+, CD8+, and NK cells over time, as well as a decrease in Treg cells, and an increased IFNγ and TNFα production by T lymphocytes. Conclusions: Taken together, our results indicate that in patients with DLBCL and B-ALL, the administration of tisagenlecleucel is capable of inducing a marked and prolonged in vivo modulation/reshaping of the host immune system, both in children and adults.

The Development of New Agents for Post-Hematopoietic Stem Cell Transplantation Non-Infectious Complications in Children.

Hematopoietic stem cell transplantation (HSCT) is often the only curative treatment option for patients suffering from various types of malignant diseases and some non-cancerous conditions. Nevertheless, it is associated with a high risk of complications leading to transplant-related mortality and long-term morbidity. An increasing number of therapeutic and prevention strategies have been developed over the last few years to tackle the complications arising in patients receiving an HSCT. These strategies have been mainly carried out in adults and some are now being translated into children. In this manuscript, we review the recent advancements in the development and implementation of treatment options for post-HSCT non-infectious complications in pediatric patients with leukemia and other non-malignant conditions, with a special attention on the new agents available within clinical trials. We focused on the following conditions: graft failure, prevention of relapse and early interventions after detection of minimal residual disease positivity following HSCT in acute lymphoblastic and myeloid leukemia, chronic graft versus host disease, non-infectious pulmonary complications, and complications of endothelial origin.

Successful sequential liver and hematopoietic stem cell transplantation in a patient with Fanconi anemia.

BACKGROUND: In Fanconi anemia bone marrow failure is the major cause of morbidity and mortality and hematopoietic stem cell transplantation represents the only curative treatment. Liver disease, in terms of elevated liver function tests, as well as benign and malignant liver tumors, occurs especially in case of androgen treatment. We report a unique case of a child with Fanconi anemia with FANCD2 mutation who developed neonatal cryptogenic liver cirrhosis and bone marrow failure. The child successfully underwent sequential liver transplantation and hematopoietic stem cell transplantation in the first 2 years of life. Nineteen months after hematopoietic stem cell transplantation and 30 months after liver transplantation, the patient is clinically well with normal hematopoietic function and excellent liver function. CONCLUSION: This is the first FA patient who successfully received sequential LT and HSCT highlighting that successful sequential transplantation is feasible in Fanconi anemia patients.

SARS-CoV-2 infections in pediatric and young adult recipients of chimeric antigen receptor T-cell therapy: an international registry report.

BACKGROUND: Immunocompromised patients are at increased risk of SARS-CoV-2 infections. Patients undergoing chimeric antigen receptor (CAR) T-cell therapy for relapsed/refractory B-cell malignancies are uniquely immunosuppressed due to CAR T-mediated B-cell aplasia (BCA). While SARS-CoV-2 mortality rates of 33%-40% are reported in adult CAR T-cell recipients, outcomes in pediatric and young adult CAR T-cell recipients are limited. METHODS: We created an international retrospective registry of CAR T recipients aged 0-30 years infected with SARS-CoV-2 within 2 months prior to or any time after CAR T infusion. SARS-CoV-2-associated illness was graded as asymptomatic, mild, moderate, or severe COVID-19, or multisystem inflammatory syndrome in children (MIS-C). To assess for risk factors associated with significant SARS-CoV-2 infections (infections requiring hospital admission for respiratory distress or supplemental oxygen), univariate and multivariable regression analyses were performed. RESULTS: Nine centers contributed 78 infections in 75 patients. Of 70 SARS-CoV-2 infections occurring after CAR T infusion, 13 (18.6%) were classified as asymptomatic, 37 (52.9%) mild, 11 (15.7%) moderate, and 6 (8.6%) severe COVID-19. Three (4.3%) were classified as MIS-C. BCA was not significantly associated with infection severity. Prior to the emergence of the Omicron variant, of 47 infections, 19 (40.4%) resulted in hospital admission and 7 (14.9%) required intensive care, while after the emergence of the Omicron variant, of 23 infections, only 1 (4.3%) required admission and the remaining 22 (95.7%) had asymptomatic or mild COVID-19. Death occurred in 3 of 70 (4.3%); each death involved coinfection or life-threatening condition. In a multivariable model, factors associated with significant SARS-CoV-2 infection included having two or more comorbidities (OR 7.73, CI 1.05 to 74.8, p=0.048) and age ≥18 years (OR 9.51, CI 1.90 to 82.2, p=0.014). In the eight patients infected with SARS-CoV-2 before CAR T, half of these patients had their CAR T infusion delayed by 15-30 days. CONCLUSIONS: In a large international cohort of pediatric and young adult CAR-T recipients, SARS-CoV-2 infections resulted in frequent hospital and intensive care unit admissions and were associated with mortality in 4.3%. Patients with two or more comorbidities or aged ≥18 years were more likely to experience significant illness. Suspected Omicron infections were associated with milder disease.