Genital GVHD in Female Children and Adolescents: A Systematic Review of Case Reports and Case Series.

Genital graft-versus-host disease (GVHD) after hematopoietic stem cell transplantation (HSCT) is an underdiagnosed manifestation of chronic GVHD. Few articles have been published in pediatric populations, and there are no established guidelines for the management of this condition in children. This study aims to provide a systematic literature review of the published studies and cases of genital (vulvovaginal) GVHD in girls and adolescents post HSCT, with a focus on the time of diagnosis and clinical manifestations. The authors searched for English-language articles published after 1990, which included full patient details. Thirty-two cases of female patients under 20 years of age were identified. The median time of diagnosis was 381 days (IQR: 226-730 days), and 83% of patients developed Grade 3 vulvovaginal GVHD. Based on these observations, an early pediatric gynecologic examination of these patients, soon within the first year after HSCT, could be suggested for early diagnosis, treatment initiation and prevention of long-term complications.

Development of a Population Pharmacokinetic Model of Busulfan in Children and Evaluation of Different Sampling Schedules for Precision Dosing.

We develop a population pharmacokinetic model to describe Busulfan pharmacokinetics in paediatric patients and investigate by simulations the impact of various sampling schedules on the calculation of AUC. Seventy-six children had 2 h infusions every 6 h. A two-compartment linear model was found to adequately describe the data. A lag-time was introduced to account for the delay of the administration of the drug through the infusion pump. The mean values of clearance, central volume of distribution, intercompartmental clearance, and peripheral volume of distribution were 10.7 L/h, 39.5 L, 4.68 L/h and 17.5 L, respectively, normalized for a Body Weight (BW) of 70 kg. BW was found to explain a portion of variability with an allometric relationship and fixed exponents of 0.75 on clearance parameters and 1 on volumes. Interindividual variability for clearance and volume of distribution was found to be 28% and 41%, respectively, and interoccasion variability for clearance was found to be 11%. Three sampling schedules were assessed by simulations for bias and imprecision to calculate AUC by a non-compartmental and a model-based method. The latter was found to be superior in all cases, while the non-compartmental was unbiased only in sampling up to 12 h corresponding to a once-daily dosing regimen.

Is Carbapenem-resistant Klebsiella pneumoniae Infection in Pediatric Bone Marrow Transplantation Recipients Inevitably Fatal?

Carbapenem resistance, most notably in Klebsiella pneumonia (KPC), results in infections associated with significant morbidity and mortality. Here we report 2 cases of adolescent patients with KPC infection after high-risk bone marrow transplantation, who eventually succumbed from other causes and review the epidemiology and treatment options for KPC infections in this vulnerable population.

Lung hyperinflation quantitated by chest CT in children with bronchiolitis obliterans syndrome following allogeneic hematopoietic cell transplantation.

OBJECTIVES: Bronchiolitis obliterans syndrome (BOS) diagnosis in children following allogeneic hematopoietic stem cell transplantation (post-HSCT) is based on detection of airway obstruction on spirometry and air-trapping, small airway thickening or bronchiectasis on chest CT. We assessed the relationship between spirometry indices and low-attenuation lung volume at total lung capacity (TLC) on CT. METHODS: Data of children post-HSCT with and without BOS were analyzed. An age-specific, low-attenuation threshold (LAT) was defined as average of (mean-1SD) lung parenchyma attenuation of 5 control subjects without lung disease matched to each age subgroup of post-HSCT patients. % CT lung volume at TLC with attenuation values

Severe aplastic anaemia in children: Impact of histopathology profile and treatment on very long-term outcomes.

AIM: To assess very long-term outcomes of children with severe aplastic anaemia (SAA) and impact of histopathology and of different treatments over time. METHODS: We conducted a retrospective study of 57 consecutive patients with SAA during 1973-2019. According to period, treatment consisted of androgens, immunosuppressive treatment (IST) and haematopoietic cell transplantation (HCT) in 14, 31 and 13 patients, respectively. Histopathology immune profiles were studied on bone marrow (BM). RESULTS: Response rate (RR) to androgens was 35%, with long-term survivorship in 4 of 5 responders. RR and 10-year overall survival (OS) after IST was 65% and 80%, respectively. RR was higher in girls (92% vs 43% in boys, P = .02). Mean baseline BM values of CD34 + and of B-lymphocytes in responders vs non-responders were 1.3% vs 0 (P = .08) and 14.1% vs 9.7% (P = .07), respectively. After IST, BM cellularity gradually increased and cytotoxic T-lymphocytes decreased (time variation P = .003 and 0.07, respectively). Outcome did not differ between patients with IST or frontline HCT. Ten-year OS improved over time, increasing from 35.3% to 77.1% and 77% during 1973-1985, 1986-2003 and 2004-2019, respectively. CONCLUSION: Histopathology may refine response prediction to IST. The course of SAA in children, a previously fatal disease, was altered in recent times.

Candidemia in Children with Malignancies: Report from the Infection Working Group of the Hellenic Society of Pediatric Hematology-Oncology.

Candidemia is an important cause of morbidity and mortality especially in immunocompromised and hospitalized patients. We retrospectively collected data of candidemia cases that occurred in the seven Hematology-Oncology Departments/Units of Greece and the Stem Cell Transplant Unit between 2015 and 2019. In total, 19 episodes of candidemia in 19 patients were recorded. The majority of the patients (78.9%) had at least one risk factor for candidemia. The most frequent risk factors associated with candidemia observed in our patients were prolonged duration of hospitalization (30 days, range 1-141), presence of a central venous catheter at diagnosis of candidemia (73.7%) and antibiotics use during the last two weeks (84.2%). Candida parapsilosis was the most common species isolated accounting for 42.1%, followed by C. albicans (26.3%) and C. famata (15.8%). Nearly all of the patients (84.2%) received antifungal monotherapy with liposomal amphotericin B or echinocandins. The central venous catheter was removed in 78.6% of patients and the median time between the first positive blood culture and catheter removal was 3 days (range 1-9). Mortality at 28 days was 26.3%. In conclusion, a predominance of non-albicans species was observed in our study in conformity with the global trend.

Proliferative and chondrogenic potential of mesenchymal stromal cells from pluripotent and bone marrow cells.

INTRODUCTION: Mesenchymal stromal cells (MSCs) can be derived from a wide range of fetal and adult sources including pluripotent stem cells (PSCs). The properties of PSC-derived MSCs need to be fully characterized, in order to evaluate the feasibility of their use in clinical applications. PSC-MSC proliferation and differentiation potential in comparison with bone marrow (BM)-MSCs is still under investigation. The objective of this study was to determine the proliferative and chondrogenic capabilities of both human induced pluripotent stem cell (hiPSC-) and embryonic stem cell (hESC-) derived MSCs, by comparing them with BM-MSCs. METHODS: MSCs were derived from two hiPSC lines (hiPSC-MSCs), the well characterized Hues9 hESC line (hESC-MSCs) and BM from two healthy donors (BM-MSCs). Proliferation potential was investigated using appropriate culture conditions, with serial passaging, until cells entered into senescence. Differentiation potential to cartilage was examined after in vitro chondrogenic culture conditions. RESULTS: BM-MSCs revealed a fold expansion of 1.18x105 and 2.3x105 while the two hiPSC-MSC lines and hESC-MSC showed 5.88x10¹°, 3.49x108 and 2.88x108, respectively. Under chondrogenic conditions, all MSC lines showed a degree of chondrogenesis. However, when we examined the formed chondrocyte micromasses by histological analysis of the cartilage morphology and immunohistochemistry for the chondrocyte specific markers Sox9 and Collagen II, we observed that PSC-derived MSC lines had formed pink rather than hyaline cartilage, in contrast to BM-MSCs. CONCLUSION: In conclusion, MSCs derived from both hESCs and hiPSCs had superior proliferative capacity compared to BM-MSCs, but they were inefficient in their ability to form hyaline cartilage.

Reprogramming of bone marrow derived mesenchymal stromal cells to human induced pluripotent stem cells from pediatric patients with hematological diseases using a commercial mRNA kit.

The potential use of patient-specific induced pluripotent stem cells (hiPSCs) in the study and treatment of hematological diseases requires the setup of efficient and safe protocols for hiPSC generation. We aimed to adopt a reprogramming method for large-scale production of integration-free patient-specific hiPSC-lines in our stem cell processing laboratory, which supports a pediatric hematopoietic stem cell transplant unit located at a tertiary care children's hospital. We describe our 5-year experience in generation of hiPSC-lines from human bone marrow-derived mesenchymal stromal cells (BM-MSCs) using synthetic mRNAs encoding reprogramming factors. We generated hiPSC-lines from pediatric patients with ß-Thalassemia, Sickle Cell Anemia, Blackfan-Diamond Anemia, Severe Aplastic Anemia, DOCK8 Immunodeficiency and 1 healthy control. After optimization of the reprogramming procedure, average reprogramming efficiency of BM-MSCs was 0.29% (range 0.25-0.4). The complete reprogramming process lasted 14-16 days. Three to five hiPSC-colonies per sample were selected, expanded to 5 culture passages and then frozen. The whole procedure took an average time of 1.8 months (range 1.6-2.2). The hiPSC-lines expressed embryonic stem cell markers and exhibited pluripotency. This mRNA reprogramming method can be applicable in a hematopoietic stem cell culture lab setting and would be useful for the clinical translation of patient-specific hiPSCs.

Successful long-term hematological and immunological reconstitution by autologous cord blood transplantation combined with post-transplant immunosuppression in two children with severe aplastic anemia.

aUCBT is a valuable curative option in pediatric patients with refractory idiopathic SAA and no available matched sibling or unrelated donors. Experience in the use of autologous cord blood units in patients with SAA is limited and private for-profit cord blood-banking programs are controversial. We report the successful treatment of two patients with SAA, aged 15 and 24 months, with autologous cord blood combined with immunosuppression. After conditioning with 200 mg/kg cyclophosphamide and ATG, 7.5 mg/kg, 32.2 × 107 /kg, and 3.8 × 107 /kg autologous cord blood nucleated cells were infused, respectively. One of our patients underwent transplantation after failure of IST. Both patients received post-transplant immunosuppression with cyclosporine for 12 months. They remain disease-free 6 years post-transplantation.

Cytokine gene polymorphisms and graft-versus-host disease in children after matched sibling hematopoietic stem cell transplantation: a single-center experience.

Various polymorphisms in cytokine genes have recently been investigated as candidate risk factors in allogeneic hematopoetic stem cell transplantation (allo-HSCT). We retrospectively analyzed specific polymorphisms in genes for interleukin (IL)-10, IL-6, tumor-necrosis factor alpha (TNF-α) and interferon gamma (IFN-γ) in a pediatric cohort of 57 histocompatibility leucocyte antigen (HLA)-identical sibling myeloablative transplants. Both recipient and donor genotypes were tested for association with graft-versus-host disease (GVHD) by statistical methods including Cox regression analysis. We found a significant association between the IL-10 promoter haplotype polymorphisms at positions -1082, -819 and -592 with the occurrence of severe (grades III-IV) acute GVHD (aGVHD). Recipients with the haplotype GCC had a statistically significant decreased risk of severe aGVHD (hazard risk (HR)=0.20, 95% confidence interval (CI): 0.06-0.67) in comparison with patients with other IL-10 haplotypes (P=0.008). Transplant-related mortality at 1 year was significantly lower in recipients with this haplotype (HR=0.17, 95% CI: 0.012-0.320) versus other IL-10 haplotypes (P=0.03), whereas overall survival was not influenced by IL-10 haplotype polymorphisms. In multivariate analysis, the presence of the IL-10 GCC haplotype was found as the only variable associated with a statistically significant decreased hazard of severe aGVHD development (P=0.02, HR=0.21, 95% CI: 0.05-0.78). These results suggest that pediatric patients possessing the IL-10 GCC haplotype may be protected from the occurrence of severe aGVHD in the setting of matched sibling HSCT.

Successful bone marrow transplantation in a pediatric patient with chronic myeloid leukemia from a HLA-identical sibling selected by preimplantation HLA testing.

We report successful bone marrow transplantation in an 11-year-old male with chronic myeloid leukemia from his HLA-identical sibling selected by preimplantation HLA testing. Because collection of cord blood failed, the transplantation was performed when the donor reached the age of 19 months, and sufficient bone marrow could be harvested safely. The patient was BCR/ABL negative at the time of transplantation after complete molecular response to imatinib. Currently, 16 months post-transplantation he is well and in complete molecular remission. This report describes preimplantation HLA-genotyping to deliver a matched sibling donor for successful transplantation of a malignant disorder.

Low usage rate of banked sibling cord blood units in hematopoietic stem cell transplantation for children with hematological malignancies: implications for directed cord blood banking policies.

Directed sibling cord blood banking is indicated in women delivering healthy babies who already have a sibling with a disease that is potentially treatable with an allogeneic cord blood transplant. We evaluated the effectiveness of a national directed cord blood banking program in sibling HLA-identical stem cell transplantation for hematological malignancies and the factors influencing the usage rate of the stored cord blood units. Fifty families were enrolled from which, 48 cord blood units were successfully collected and 2 collections failed due to damaged cord/placenta at delivery. Among enrolled families 4 children needed transplantation; however, only one was successfully transplanted using the collected cord blood unit containing 2×10(7) nucleated cells/kg in conjunction with a small volume of bone marrow from the same HLA-identical donor. Two children received grafts from matched unrelated donors because their sibling cord blood was HLA-haploidentical, while the fourth one received bone marrow from his HLA-identical brother, since cord blood could not be collected due to damaged cord/placenta at delivery. With a median follow-up of 6 years (range, 2-12) for the 9 remaining HLA-matched cord blood units, none from the prospective recipients needed transplantation. The low utilization rate of sibling cord blood in the setting of hematopoietic stem cell transplantation for pediatric hematological malignant diseases necessitates the development of directed cord blood banking programs that limit long-term storage for banked cord blood units with low probability of usage such as non-HLA-identical or identical to patients who are in long-term complete remission.

Acute gastrointestinal graft-versus-host disease in pediatric patients: serum albumin on day 5 from initiation of therapy correlates with nonrelapse mortality and overall survival.

The aim of the present study was to identify factors associated with the risk of development of gastrointestinal acute graft-versus-host disease (GI-aGVHD), as well as to evaluate the impact of various baseline parameters on response to treatment, nonrelapse mortality (NRM), and overall survival (OS) in pediatric patients with GI-aGVHD after allogeneic hematopoietic stem cell transplantation (allo-SCT). We retrospectively analyzed 300 pediatric patients who underwent allo-SCT from HLA-matched related or volunteer unrelated donors in our institution. GI tract involvement was observed in 46 out of 133 patients with aGVHD grade II-IV. Severe aGVHD (grade III-IV) was more frequently observed among patients with GI-aGVHD in comparison with patients without GI involvement (P < .001). Treatment with steroids resulted in durable responses in 22/46 patients; 14 additional patients responded to salvage therapy, whereas 10 were refractory to all treatments administered. Using Cox regression analysis, we observed that serum albumin level ≥ 3 mg/dL on day 5 after the initiation of therapy with steroids was statistically significantly associated with decreased hazard of NRM and improved OS (P = .021 and P = .026, respectively). In our study, serum albumin level, early (+ day 5) after the onset of steroids in patients with GI-aGVHD, was a predictor of treatment outcome. Prospective randomized trials need to be performed to verify the predictive significance of serum albumin and the need for early intensification of immunosuppressive treatment.

Directed sibling donor cord blood banking for children with beta-thalassemia major in Greece: usage rate and outcome of transplantation for HLA-matched units.

Several cord blood banks store cord blood units from healthy siblings of patients, who are candidates for stem cell transplantation. We analyzed the quality characteristics of 50 cord blood units collected from families with beta-thalassemia major and the outcome of subsequent stem cell transplantations during a 15-year period. All cord blood units were found suitable for banking based on a minimum net volume of 40 ml. The mean volume of the units was 98.9 ml; the mean total nucleated cell count (NC) was 7.8 x 10(8) and the mean CD34+ cell count was 2.8 x 10(6). Eight out of twelve HLA matched collections were released for transplantation. All but one recipient belonged to Pesaro II-III risk classes. Three patients received a cord blood graft with >5 x 10(7) NC/kg . One of them with Pesaro class I disease engrafted, whereas the other two who failed to engraft, were re-transplanted with bone marrow from the same donor later. Cord blood grafts containing NCs <4 x 10(7)/kg combined with reduced volume bone marrow from the same donor were used in all 5 remaining cases and stable engraftment was achieved. All patients survived, 7/8 thalassemia-free. Cord blood banking from healthy siblings of children with beta-thalassemia major can result in a successful transplantation in cases in which there is HLA compatibility. However, in high-risk patients, the use of combined cord blood and bone marrow grafts seems necessary in order to ensure stable engraftment, especially when cord blood unit cell counts are low.

Successful hematopoietic stem cell transplantation in 2 children with X-linked chronic granulomatous disease from their unaffected HLA-identical siblings selected using preimplantation genetic diagnosis combined with HLA typing.

We report 2 children with X-linked chronic granulomatous disease (X-CGD) who underwent hematopoietic stem cell transplantation (HSCT) using grafts from their siblings selected before implantation to be both unaffected and HLA-matched donors. Preimplantation genetic diagnosis (PGD) along with HLA-typing were performed on preimplantation embryos by single-cell multiplex polymerase chain reaction using informative short tandem repeat markers in the HLA locus together with the gene region containing the mutations. Two singleton pregnancies resulted from the intrauterine transfer of selected embryos; these developed to term, producing 1 healthy female and 1 X-CGD carrier female, which are HLA-identical siblings to the 2 affected children. Combined grafts of umbilical cord blood (UCB) and bone marrow (BM) stem cells were administered to the recipients after myeloablative (MA) conditioning at the ages of 4.5 years and 4 years, respectively. Both patients are well, with complete donor hematopoietic and immunologic reconstitution, at 18 and 13 months posttransplantation, respectively. This report demonstrates that HSCT with HLA-matched sibling donors created by PGD/HLA typing of in vitro fertilized embryos is a realistic therapeutic option and should be presented as such to families with children who require a non-urgent HSCT but lack an HLA-genoidentical donor.