The role of donor type and pre-transplant immunosuppression on outcomes of hematopoietic stem cell transplantation in children and young adults with severe aplastic anemia.

BACKGROUND: The goal of this study was to assess the effect of donor type and pre-transplant immunotherapy (IST) on outcomes of hematopoietic stem cell transplantation (HSCT) for children and young adults with severe aplastic anemia (SAA). METHODS: This retrospective, multi-center study included 52 SAA patients, treated in 5 pediatric transplant programs in Florida, who received HSCT between 2010 and 2020 as the first- or second-line treatment. RESULTS: The median age at HSCT for all 52 patients was 15 years (range 1-25). The 3-year overall survival (OS) by donor type were as follows: 95% [95% CI 85.4-99] for matched related donors (MRD) (N = 24), 84% [95% CI 63.5-99] for haploidentical (N = 13), and 71% [95% CI 36-99] for matched unrelated donors (MUD) (N = 7). The 3-year OS was 81% [95% CI 69.7-99] for all patients, 90.5% [95% CI 79.5-99] for non-IST patients (N = 27), and 70% [95% CI 51-99] for IST patients (N = 24) (log-rank p = .04). Survival of haploidentical HSCT (haplo-HSCT) recipients with post-transplant cyclophosphamide (PTCy) (N = 13) was excellent for both groups: 100% for non-IST patients (N = 3) and 80% for IST patients (N = 10). The 3-year OS for patients with previous IST by donor type in groups where >5 patients were available was 78.8% [95% CI 52.3-99] for haplo-HSCT (N = 10) and 66.7% [95% CI 28.7-99] for MUD (N = 6). Although it appears that patients receiving HSCT ≥6 months after the start of IST had worse survival, the number of patients in each category was small and log-rank was not significant(p = .65). CONCLUSIONS: Patients receiving MUD and haplo-HSCT with PTCy had similar outcomes, suggesting that haplo-HSCT with PTCy could be included in randomized trials of upfront IST versus alternative donor HSCT.

Burkitt lymphoma after solid-organ transplant: Treatment and outcomes in the paediatric PTLD collaborative.

Burkitt lymphoma arising in paediatric post-solid-organ transplantation-Burkitt lymphoma (PSOT-BL) is a clinically aggressive malignancy and a rare form of post-transplant lymphoproliferative disorder (PTLD). We evaluated 35 patients diagnosed with PSOT-BL at 14 paediatric medical centres in the United States. Median age at organ transplantation was 2.0 years (range: 0.1-14) and age at PSOT-BL diagnosis was 8.0 years (range: 1-17). All but one patient had late onset of PSOT-BL (≥2 years post-transplant), with a median interval from transplant to PSOT-BL diagnosis of 4.0 years (range: 0.4-12). Heart (n = 18 [51.4%]) and liver (n = 13 [37.1%]) were the most frequently transplanted organs. No patients had loss of graft or treatment-related mortality. A variety of treatment regimens were used, led by intensive Burkitt lymphoma-specific French-American-British/Lymphomes Malins B (FAB/LMB), n = 13 (37.1%), and a low-intensity regimen consisting of cyclophosphamide, prednisone and rituximab (CPR) n = 12 (34.3%). Median follow-up was 6.7 years (range: 0.5-17). Three-year event-free and overall survival were 66.2% and 88.0%, respectively. Outcomes of PSOT-BL patients receiving BL-specific intensive regimens are comparable to reported BL outcomes in immunocompetent children. Multi-institutional collaboration is feasible and provides the basis of prospective data collection to determine the optimal treatment regimen for PSOT-BL.

Post-SARS-CoV-2 Atypical Inflammatory Syndrome in a Toddler with X-Linked Inhibitor of Apoptosis Deficiency After Stem Cell Transplant.

A 10-month-old boy was diagnosed with X-linked lymphoproliferative syndrome type 2 due to X-linked inhibitor of apoptosis deficiency after presenting with failure to thrive and refractory inflammatory bowel disease. He underwent a matched unrelated donor stem cell transplant with reduced intensity conditioning at 16 months. At 27 months, he presented with an atypical inflammatory syndrome in the setting of recent COVID-19 infection, Epstein-Barr viremia, and low chimerism (7.3%). He recovered after treatment with intravenous immunoglobulin and steroids.

Race as a factor in donor selection and survival of children with hematologic malignancies undergoing hematopoietic stem cell transplant in Florida.

BACKGROUND: Previous studies have explored posthematopoietic cell transplant (HCT) outcomes by race in adults; however, pediatric data addressing this topic are scarce. PROCEDURE: This retrospective registry study included 238 White (W) and 57 Black (B) children with hematologic malignancies (HM) receiving first allogeneic HCT between 2010 and 2019 at one of the five Florida pediatric HCT centers. RESULTS: We found no differences between W and B children in transplant characteristics, other than donor type. There was a significant difference in use of human leukocyte antigen (HLA)-mismatched donors (HLA-MMD) (53% W, 71% B, p = .01). When comparing HLA-MMD use to fully HLA-matched donors, B had relative risk (RR) of 1.47 (95% CI 0.7-3) of receiving a mismatched unrelated donor (MMUD), RR of 2.34 (95% CI 1.2-4.4) of receiving a mismatched related donor (MMRD), and RR of 1.9 (95% CI 0.99-3.6) of receiving a mismatched cord blood donor (MMCBD) HCT, respectively. There was no significant difference in the incidence of aGVHD (48% W, 35% B), p = .1, or cGVHD (19% W, 28% B, p = .1), or primary cause of death. Overall 24-month survival was 61% (95% CI 55%-68%) for W, and 60% (95% CI 48-75) for B children, log-rank p = .7. While HLA matching improved survival in W children, the number of B children receiving HLA-matched HCT was too small to identify the impact of HLA matching on survival. CONCLUSIONS: In this contemporary cohort of children with HM, we found that B children were more likely to receive HLA-MMD transplants, but this did not adversely affect survival or GVHD rates.

Pediatric HCT in Florida (2014 -2016): A report from the FPBCC.

FPBCC was formed in 2018 by five pediatric transplant programs in Florida. One of the key objectives of the consortium is to provide outcome analyses by combining HCT data from all the participating centers in order to identify areas for improvement. In this first FPBCC landscape report we describe the patient and transplant characteristics of pediatric patients undergoing first allo and auto HCT between 2014 and 2016 in Florida. The source of data was eDBtC of the CIBMTR. Over the span of 3 years, a total of 230 pediatric patients underwent allo-HCT and 104 underwent auto-HCT at the participating centers. The most significant predictor of survival in allo-HCT recipients with malignant disorders was the degree of HLA- match, while in the recipients of allo-HCT with non-malignant disorders the predictors of survival included age, donor relationship and degree of HLA match. Our analyses identified the need to improve reporting of primary cause of death and improve on donor selection process given that the degree of HLA match remains the most important predictor of survival. This first FPBCC-wide review describes the trends in pediatric HCT activity between 2014 and 2016 among the participating centers in Florida and confirms feasibility of using eDBtC data platform and collaborative approach in order to identify areas for improvement in outcomes.

Very Low Numbers of CD4+ FoxP3+ Tregs Expanded in Donors via TL1A-Ig and Low-Dose IL-2 Exhibit a Distinct Activation/Functional Profile and Suppress GVHD in a Preclinical Model.

Regulatory T cells (Tregs) are essential for the maintenance of tolerance and immune homeostasis. In allogeneic hematopoietic stem cell transplantation (aHSCT), transfer of appropriate Treg numbers is a promising therapy for the prevention of graft-versus-host disease (GVHD). We have recently reported a novel approach that induces the marked expansion and selective activation of Tregs in vivo by targeting tumor necrosis factor receptor superfamily 25 (TNFRSF25) and CD25. A potential advance to promote clinical application of Tregs to ameliorate GVHD and other disorders would be the generation of more potent Treg populations. Here we wanted to determine if very low doses of Tregs generated using the "2-pathway" stimulation protocol via TL1A-Ig fusion protein and low-dose IL-2 (targeting TNFRSF25 and CD25, respectively) could be used to regulate preclinical GVHD. Analysis of such 2-pathway expanded Tregs identified higher levels of activation and functional molecules (CD103, ICOS-1, Nrp-1, CD39, CD73, il-10, and tgfb1) versus unexpanded Tregs. Additionally, in vitro assessment of 2-pathway stimulated Tregs indicated enhanced suppressor activity. Notably, transplant of extremely low numbers of these Tregs (1:6 expanded Tregs/conventional T cells) suppressed GVHD after an MHC-mismatched aHSCT. Overall, these results demonstrate that 2-pathway stimulated CD4+ FoxP3+ Tregs were quantitatively and qualitatively more functionally effective than unexpanded Tregs. In total, the findings in this study support the notion that such 2-pathway stimulated Tregs may be useful for prevention of GVHD and ultimately promote more widespread application of aHSCT in the clinic.

Prevalence of Hypertension (HTN) and Cardiovascular Risk Factors in a Hospitalized Pediatric Hemophilia Population.

Improved life expectancy in hemophilia has led to a greater interest in age-related disorders. Hypertension (HTN) as well as cardiovascular disease have been increasingly reported in hemophilic adults but there is currently very limited data in the pediatric population. We conducted a cross-sectional study using data from the 2012 National Health Cost and Utilization Project database to determine the prevalence of HTN and associated cardiovascular risk factors in a hospitalized pediatric hemophilia population, between the ages of 0 to 21 years, in comparison with the general pediatric population. The prevalence of HTN was significantly higher in children with hemophilia (CWH) in comparison with the general pediatric population (1.71% vs. 1.02%, P-value=0.005). When adjusting the analysis for sex, the prevalence of HTN in the hemophilia cohort remained higher, although not statistically significant (1.52% vs. 1.22%, P-value=0.2568). When examining the concomitant presence of ≥1 cardiovascular risk factors in the hypertensive subgroups, CWH had a higher prevalence of obesity (2.64% vs. 1.32%, P-value <0.0001). Interestingly, diabetes mellitus was more prevalent in nonhemophilic children (1.47% vs. 0.56%, P-value=0.0015). These data suggest that cardiovascular risk factors need to be closely monitored in CWH, and a better preventive strategy is likely needed to identify those hemophilic patients at higher risk of developing cardiovascular disease in adulthood.

Sexual Dysfunction Among Adolescent and Young Adult Men Diagnosed with Cancer.

Purpose: Adolescent and young adult (AYA) cancer patients frequently demonstrate sexual dysfunction; however, there is a lack of data quantifying the severity and frequency. Methods: Males aged 18-39 years, diagnosed with cancer of any kind and who were scheduled to begin, were actively receiving, or had completed cancer treatment within 6 months, were offered validated surveys during their oncology appointment. These surveys included the International Index of Erectile Function (IIEF-6), Masturbation Erection Index (MEI), 36-Item Short Form Survey, and 5-point Likert scales to assess their desire and ability to engage in sex and masturbation. Results: Forty subjects completed the IIEF survey with a mean score of 17.7 ± 11, erectile dysfunction (ED) prevalence accordingly was 58%. Thirty-eight subjects completed the MEI with a mean score of 25.3 ± 5.3, ED prevalence was again 58%. Age and IIEF scores demonstrated a statistically significant (p < 0.05, n = 38) Pearson's correlation coefficient of 0.40, patients younger than 30 years had an ED prevalence of 72% (mean IIEF 13), whereas patients aged 30 years and older had an ED prevalence of 45% (mean IIEF 22). All treatment modalities had ED rates >30%: chemotherapy demonstrated the highest prevalence at 64% (mean IIEF 17), whereas radiation therapy had the lowest prevalence at 33% (mean IIEF 23). Conclusion: This study demonstrates that the prevalence of sexual dysfunction among male AYA patients undergoing treatment for cancer is high. AYA oncologists should discuss potential sexual health concerns when treating this population. The exact cause of ED (non-organic vs. organic) within this group should be explored further.

Evolving Strategies in the Management of Sickle Cell Disease in the 21st Century and the Role of the Pediatrician.

Sickle cell disease (SCD) is one of the most common genetic disorders in the United States. Once a fatal disease of childhood, the majority of patients born with SCD who live in a developed country will survive to adulthood (albeit with slightly shortened life spans). Despite numerous novel therapeutic advancements in recent years that serve to mitigate the symptoms associated with SCD, the only cure for SCD is a hematopoietic stem cell transplant. The overall survival for patients with a matched sibling donor transplant is greater than 90%. However, fewer than 20% of patients with SCD in the US have a 12/12 human leukocyte antigen (HLA) matched sibling donor. In contrast, most patients have at least one HLA haploidentical first-degree relative, which expands the donor pool for patients who have diseases amenable to stem cell transplantation such as SCD. [Pediatr Ann. 2022;51(1):e34-e39.].

Treatment of allograft renal cell carcinoma with partial nephrectomy in a pediatric kidney transplant.

Renal cell carcinoma (RCC) is a common malignancy among kidney transplant recipients that often occurs in the native kidney. The incidence of RCC in the renal allograft is rare and carries the double risk of returning to dialysis and the development of metastatic cancer. The majority of reported cases of RCC in transplanted kidneys are in adult recipients and its occurrence in the pediatric age group is an uncommon event. There are currently no established guidelines on the treatment of RCC in transplant recipients. We report our experience of a 15-year-old male who developed allograft RCC 12 years later after transplantation. MRI confirmed the presence of the mass near the hilum of the renal allograft and biopsy revealed a Papillary Renal Cell Carcinoma (PRCC) type I. A partial allograft nephrectomy was successfully performed with negative tumor margins. The patient's serum creatinine 12 months post-operation was 1.9 mg/dL and presently he has no evidence of residual disease, recurrence, or metastasis. Partial nephrectomy is an effective treatment option for renal allograft RCC as it spares the patient from returning to dialysis until retransplantation is possible and necessary.

Pediatric Acute Lymphoblastic Leukemia: From Diagnosis to Prognosis.

Pediatric acute lymphoblastic leukemia is the most common childhood cancer. Although the appearance of the disease is often quite dramatic, there are many patients who present much more indolently, creating a diagnostic dilemma for the primary care pediatrician. The appropriate diagnostic work-up assesses the initial extent of disease and stability of a patient, and provides information that is important for risk stratification. Such information includes patient age and white blood cell count at diagnosis, leukemia immunophenotype, presence or absence of extramedullary disease, and blast cytogenetic abnormalities. After therapy is initiated, the response of the disease to treatment is key for predicting outcomes. Altogether, this information is used to guide overall treatment intensity. Chemotherapy is administered in sequential blocks or phases, and lasts for several years. In general, outcomes are excellent and the majority of patients survive, but there are still subsets of patients who do not fare as well, either due to resistant or recurrent disease, or due to long-term and late effects of therapy.