Relevance of lymphocyte proliferation to PHA in severe combined immunodeficiency (SCID) and T cell lymphopenia

Severe combined immunodeficiency (SCID) is characterized by a severe deficiency in T cell numbers. We analyzed data collected (n = 307) for PHA-based T cell proliferation from the PIDTC SCID protocol 6901, using either a radioactive or flow cytometry method. In comparing the two groups, a smaller number of the patients tested by flow cytometry had <10% of the lower limit of normal proliferation as compared to the radioactive method (p = 0.02). Further, in patients with CD3+ T cell counts between 51 and 300 cells/μL, there was a higher proliferative response with the PHA flow assay compared to the 3H-T assay (p < 0.0001), suggesting that the method of analysis influences the resolution and interpretation of PHA results. Importantly, we observed many SCID patients with profound T cell lymphopenia having normal T cell proliferation when assessed by flow cytometry. We recommend this test be considered only as supportive in the diagnosis of typical SCID.

Return to school practices after hematopoietic cell transplantation: a survey of transplant centers in the United States

To understand transplant center recommendations on return-to-school timing and related support for hematopoietic cell transplant (HCT) survivors, we conducted a two-phase, cross-sectional, web-based survey: In Phase I, medical directors of pediatric HCT centers from the National Marrow Donor Program/ Be The Match Registry were asked regarding the availability of a return to school standardized operating procedure (SOP). In Phase II, HCT physician members of the Pediatric Transplantation and Cellular Therapy Consortium were approached to study inter-physician practice variability regarding return to school post-HCT, factors affecting their decision-making, and support provided by HCT centers for return to school. Out of 46 respondents in Phase I (55% response rate), 28 (61%) reported having a SOP. Wide variations in recommendations were noted in 12 received SOPs. In Phase II, 122 physicians (60 centers) responded (30.6% response rate). The majority (60%) recommended autologous HCT recipients return to school within 6 months post-HCT but 65% recommended allogeneic HCT recipients return to school after 6 months or once off immunosuppression. Our findings indicate a lack of consensus within and across HCT centers regarding recommended return to school timing and underscore need for a guideline to standardize this process to ensure patient safety and re-integration into school.

Posttransplantation late complications increase over time for patients with SCID: A Primary Immune Deficiency Treatment Consortium (PIDTC) landmark study

BACKGROUND

The Primary Immune Deficiency Treatment Consortium (PIDTC) enrolled children in the United States and Canada onto a retrospective multicenter natural history study of hematopoietic cell transplantation (HCT).

OBJECTIVE

We investigated outcomes of HCT for severe combined immunodeficiency (SCID).

METHODS

We evaluated the chronic and late effects (CLE) after HCT for SCID in 399 patients transplanted from 1982 to 2012 at 32 PIDTC centers. Eligibility criteria included survival to at least 2 years after HCT without need for subsequent cellular therapy. CLE were defined as either conditions present at any time before 2 years from HCT that remained unresolved (chronic), or new conditions that developed beyond 2 years after HCT (late).

RESULTS

The cumulative incidence of CLE was 25% in those alive at 2 years, increasing to 41% at 15 years after HCT. CLE were most prevalent in the neurologic (9%), neurodevelopmental (8%), and dental (8%) categories. Chemotherapy-based conditioning was associated with decreased-height z score at 2 to 5 years after HCT (P < .001), and with endocrine (P < .001) and dental (P = .05) CLE. CD4 count of ≤500 cells/μL and/or continued need for immunoglobulin replacement therapy >2 years after transplantation were associated with lower-height z scores. Continued survival from 2 to 15 years after HCT was 90%. The presence of any CLE was associated with increased risk of late death (hazard ratio, 7.21; 95% confidence interval, 2.71-19.18; P < .001).

CONCLUSION

Late morbidity after HCT for SCID was substantial, with an adverse impact on overall survival. This study provides evidence for development of survivorship guidelines based on disease characteristics and treatment exposure for patients after HCT for SCID.

Hemophagocytic Lymphohistiocytosis in Adolescents and Young Adults: Genetic Predisposition and Secondary Disease

Hemophagocytic lymphohistiocytosis (HLH) is a disorder of impaired immune regulation resulting in hyperinflammation that is ultimately fatal if not treated. HLH is categorized into familial disease, caused by genetic mutations affecting the function of cytotoxic T lymphocytes and natural killer cells, and secondary disease, triggered by infections, malignancies, rheumatologic disorders, or immune deficiency. Adolescent and young adults with HLH represent a unique population with specific diagnostic challenges. Here we review the diagnostic criteria, possible etiologies, pathophysiology, and management of HLH with focus on the adolescent population.

Measuring the effect of newborn screening on survival after haematopoietic cell transplantation for severe combined immunodeficiency: a 36-year longitudinal study from the Primary Immune Deficiency Treatment Consortium

BACKGROUND

Severe combined immunodeficiency (SCID) is fatal unless durable adaptive immunity is established, most commonly through allogeneic haematopoietic cell transplantation (HCT). The Primary Immune Deficiency Treatment Consortium (PIDTC) explored factors affecting the survival of individuals with SCID over almost four decades, focusing on the effects of population-based newborn screening for SCID that was initiated in 2008 and expanded during 2010-18.

METHODS

We analysed transplantation-related data from children with SCID treated at 34 PIDTC sites in the USA and Canada, using the calendar time intervals 1982-89, 1990-99, 2000-09, and 2010-18. Categorical variables were compared by χ2 test and continuous outcomes by the Kruskal-Wallis test. Overall survival was estimated by the Kaplan-Meier method. A multivariable analysis using Cox proportional hazards regression models examined risk factors for HCT outcomes, including the variables of time interval of HCT, infection status and age at HCT, trigger for diagnosis, SCID type and genotype, race and ethnicity of the patient, non-HLA-matched sibling donor type, graft type, GVHD prophylaxis, and conditioning intensity.

FINDINGS

For 902 children with confirmed SCID, 5-year overall survival remained unchanged at 72%-73% for 28 years until 2010-18, when it increased to 87% (95% CI 82·1-90·6; n=268; p=0·0005). For children identified as having SCID by newborn screening since 2010, 5-year overall survival was 92·5% (95% CI 85·8-96·1), better than that of children identified by clinical illness or family history in the same interval (79·9% [69·5-87·0] and 85·4% [71·8-92·8], respectively [p=0·043]). Multivariable analysis demonstrated that the factors of active infection (hazard ratio [HR] 2·41, 95% CI 1·56-3·72; p<0·0001), age 3·5 months or older at HCT (2·12, 1·38-3·24; p=0·001), Black or African-American race (2·33, 1·56-3·46; p<0·0001), and certain SCID genotypes to be associated with lower overall survival during all time intervals. Moreover, after adjusting for several factors in this multivariable analysis, HCT after 2010 no longer conveyed a survival advantage over earlier time intervals studied (HR 0·73, 95% CI 0·43-1·26; p=0·097). This indicated that younger age and freedom from infections at HCT, both directly driven by newborn screening, were the main drivers for recent improvement in overall survival.

INTERPRETATION

Population-based newborn screening has facilitated the identification of infants with SCID early in life, in turn leading to prompt HCT while avoiding infections. Public health programmes worldwide can benefit from this definitive demonstration of the value of newborn screening for SCID.

FUNDING

National Institute of Allergy and Infectious Diseases, Office of Rare Diseases Research, and National Center for Advancing Translational Sciences.

The impacts of total body irradiation on umbilical cord blood hematopoietic stem cell transplantation

Background

Umbilical cord blood hematopoietic stem cells are commonly used for hematopoietic system reconstitution in recipients after umbilical cord blood transplantation (UCBT). However, the optimal conditioning regimen for UCBT remains a topic of debate. The exact impact of total body irradiation (TBI) as a part of conditioning regimens remains unknown.

Objectives

The aim of this study was to evaluate the impacts of TBI on UCBT outcomes.

Design

This was a multi-institution retrospective study.

Methods

A retrospective analysis was conducted on the outcomes of 136 patients receiving UCBT. Sixty-nine patients received myeloablative conditioning (MAC), in which 33 underwent TBI and 36 did not, and 67 patients received reduced-intensity conditioning (RIC), in which 43 underwent TBI and 24 did not. Univariate and multivariate analyses were conducted to compare the outcomes and the post-transplant complications between patients who did and did not undergo TBI in the MAC subgroup and RIC subgroup, respectively.

Results

In the RIC subgroup, patients who underwent TBI had superior overall survival (adjusted hazard ratio [aHR] = 0.25, 95% confidence interval [CI]: 0.09-0.66, p = 0.005) and progression-free survival (aHR = 0.26, 95% CI: 0.10-0.66, p = 0.005). However, in the MAC subgroup, there were no statistically significant differences between those receiving and not receiving TBI.

Conclusion

In the setting of RIC in UCBT, TBI utilization can improve overall survival and progression-free survival. However, TBI does not show superiority in the MAC setting.

Evaluation of Children with Malignancies for Blood and Marrow Transplantation: A Report from the ASTCT Committee on Practice Guidelines

Evaluation of a candidate for hematopoietic cell transplantation (HCT) is a complex process with substantial intercenter variability. Although literature providing guidance for evaluating the eligibility of adults is well established, similar guidance for children is lacking. To address gaps between adult recommendations and the specific needs of children, we convened a panel of pediatric HCT experts from a wide geographic range of American Society of Transplantation and Cellular Therapy (ASTCT) member institutions to offer recommendations for pediatric-focused pre-HCT evaluation. In this report from the ASTCT Committee on Practice Guidelines, we present a practical framework for evaluating children with malignancies who are candidates for HCT. We also highlight key differences from adults and emphasize areas of unmet need that require additional research to delineate best practices.

Real-world data showing trends and outcomes by race and ethnicity in allogeneic hematopoietic cell transplantation: a report from the Center for International Blood and Marrow Transplant Research

BACKGROUND

Use of human leukocyte antigen (HLA)-mismatched donors could enable more patients with ethnically diverse backgrounds to receive allogeneic hematopoietic cell transplantation (HCT) in the United States. However, real-world trends and outcomes following mismatched donor HCT for diverse patients remain largely undefined.

OBJECTIVE

To determine whether mismatched donor platforms have increased access to allogeneic HCT for ethnically diverse patients, particularly through the application of novel graft-versus-host disease (GvHD) prophylaxis regimens, and if outcomes for diverse patients were comparable to those of non-Hispanic White patients.

DESIGN

Observational cross-sectional study using real-world data from the Center for International Blood and Marrow Transplant Research (CIBMTR) registry. All patients receiving their first allogeneic HCT in the U.S. from 2009-2020 with focus on transplants performed in 2020 were included. Data from patients receiving allogeneic HCT using bone marrow, peripheral blood or cord blood from HLA-matched or mismatched related and unrelated donors was analyzed. Specifically, relative proportions of allogeneic HCT were generated as percent of total for donor type and for patient age, disease indication, GvHD prophylaxis, and race and ethnicity. Causes of death were summarized using frequencies, and the Kaplan-Meier estimator was used for estimating overall survival.

RESULTS

Compared to matched related donor and matched unrelated donor HCT, more ethnically diverse patients received mismatched unrelated donor, haploidentical donor, and cord blood HCT. Matched unrelated donor remains the most common donor type, but use of haploidentical donors has increased significantly over the last 5 years. Paralleling the increase in haploidentical HCT is the increased use of post-transplant cyclophosphamide (PTCy) as GvHD prophylaxis. Relative to older transplant eras, the most contemporary transplant era associates with the highest survival rates following allogeneic HCT irrespective of patient race and ethnicity. However, disease relapse remains the primary cause of death for both adult and pediatric allogeneic HCT recipients by donor type and across all patient race and ethnicity groups.

CONCLUSIONS

Ethnically diverse patients are undergoing allogeneic HCTs at higher rates largely through the use of alternative donor platforms incorporating PTCy. Maintaining access to potential life-saving allogeneic HCT using alternative donors and novel GvHD prophylaxis strategies and improving HCT outcomes, particularly disease relapse, are urgent clinical needs.

Effect of Autograft CD34+ Dose on Outcome in Pediatric Patients Undergoing Autologous Hematopoietic Stem Cell Transplant for Central Nervous System Tumors

BACKGROUND

Consolidation with autologous hematopoietic stem cell transplantation (HSCT) has improved survival for patients with central nervous system tumors (CNSTs). The impact of the autologous graft CD34+ dose on patient outcomes is unknown.

OBJECTIVES

To analyze the relationship between CD34⁺ dose, total nucleated cell (TNC) dose, and clinical outcomes, including overall survival (OS), progression free survival (PFS), relapse, non-relapse mortality (NRM), endothelial-injury complications (EIC), and time to neutrophil engraftment in children undergoing autologous HSCT for CNSTs.

STUDY DESIGN

A retrospective analysis of the CIBMTR database was performed. Children aged <10 years who underwent autologous HSCT between 2008-2018 for an indication of CNST were included. An optimal cut point was identified for patient age, CD34⁺ cell dose, and TNC, using the maximum likelihood method and PFS as an endpoint. Univariable analysis for PFS, OS, and relapse was described using the Kaplan-Meier estimator. Cox models were fitted for PFS and OS outcomes. Cause-specific hazards models were fitted for relapse and NRM.

RESULTS

One hundred fifteen patients met the inclusion criteria. A statistically significant association was identified between autograft CD34+ content and clinical outcomes. Children receiving >3.6×10⁶/kg CD34⁺ cells experienced superior PFS (p=0.04) and OS (p=0.04) compared to children receiving ≤3.6×10⁶/kg. Relapse rates were lower in patients receiving >3.6×10⁶/kg CD34⁺ cells (p=0.05). Higher CD34⁺ doses were not associated with increased NRM (p=0.59). Stratification of CD34⁺ dose by quartile did not reveal any statistically significant differences between quartiles for 3-year PFS (p=0.66), OS (p=0.29), risk of relapse (p=0.57), or EIC (p=0.87). There were no significant differences in patient outcomes based on TNC, and those receiving a TNC >4.4×10⁸/kg did not experience superior PFS (p=0.26), superior OS (p=0.14), reduced risk of relapse (p=0.37), or reduced NRM (p=0.25). Children with medulloblastoma had superior PFS (p<0.001), OS (p=0.01), and relapse rates (p=0.001) compared to those with other CNS tumor types. Median time to neutrophil engraftment was 10 days vs 12 days in the highest and lowest infused CD34+ quartiles, respectively.

CONCLUSIONS

For children undergoing autologous HSCT for CNSTs, increasing CD34⁺ cell dose was associated with significantly improved OS and PFS, and lower relapse rates, without increased NRM or EICs.

What Causes Aplastic Anaemia: Results of Transplants from Genetically-Identical Twins

Background

Aplastic anaemia has diverse aetiologies. Distinguishing between these is, in part, testable by analyzing results of haematopoietic cells transplants between genetically-identical twins one of whom has aplastic anaemia.

Objective

Describe outcomes of genetically-identical twin transplants for aplastic anaemia with and without pretransplant conditioning.

Methods

We interrogated data from an observational database of 59 consecutive recipients of genetically-identical twin transplants for aplastic anaemia reported to the Center for International Blood and Marrow Transplant Research (CIBMTR) 2000-2019.

Results

38 subjects were male. Median age was 18 years (Interquartile Range [IQR], 11-32 years). Median interval from diagnosis to transplant was 2 months (IQR 1-3 months). 11 subjects received a 1st transplant without pretransplant conditioning. 2 of recovered normal bone marrow function. The other 9 received a 2nd transplant with pretransplant conditioning 7 of whom recovered. 48 subjects received pretransplant conditioning before a 1st or 2nd transplant all of whom recovered.

Conclusion

Only some genetically-identical twins with aplastic anaemia recover normal bone marrow function after a 1st haematopoietic cell transplant without pretransplant conditioning whereas most subjects recover when a transplant is preceded by pretransplant conditioning. These data are consistent with an immune-mediated aetiology of aplastic anaemia in most cases.

Expanded HCT-CI Definitions Capture Comorbidity Better for Younger Patients of Allogeneic HCT for Nonmalignant Diseases

Allogeneic hematopoietic cell transplantation (HCT) can cure many nonmalignant conditions, but concern for morbidity and mortality remains. To help physicians estimate patient-specific transplant mortality risk, the HCT comorbidity index (HCT-CI) is used. However, pediatric physicians use the HCT-CI less frequently than adult counterparts. We used the Center for International Blood and Marrow Transplant Research database to expand the HCT-CI comorbidity definitions to be more inclusive of children and adolescent and young adult (AYA) patients, adding history of mechanical ventilation, history of invasive fungal infection, assessment of chronic kidney disease (CKD) by estimated glomerular filtration rate, expanding the definition of obesity, and adding an underweight category. A total of 2815 children and AYAs (<40 years old) who received first allogeneic HCT for nonmalignant diseases from 2008 to 2017 were included to create an expanded youth nonmalignant HCT-CI (expanded ynHCT-CI) and a simplified non-malignant (simplified ynHCT-CI) HCT-CI. The expanded comorbidities occurred frequently-history of mechanical ventilation (9.6%), history of invasive fungal infection (5.9%), mild CKD (12.2%), moderate/severe CKD (2.1%), obesity (10.9%), and underweight (14.5%). Thirty-nine percent of patients had an increase in their comorbidity score using the expanded ynHCT-CI, leading to a redistribution of scores: ynHCT-CI score 0 (35%), 1-2 (36.4%), and ≥3 (28.6%). Patients with an increase in their comorbidity score had an increased hazard of mortality compared to those whose score remained the same (hazard ratio = 1.41; 95% confidence interval, 1.01-1.98). Modifications to the HCT-CI can benefit children and AYA patients with nonmalignant diseases, creating a risk assessment tool that is clinically relevant and better captures comorbidity in this younger population.

The diagnosis of severe combined immunodeficiency: Implementation of the PIDTC 2022 Definitions

BACKGROUND

Shearer et al in 2014 articulated well-defined criteria for the diagnosis and classification of severe combined immunodeficiency (SCID) as part of the Primary Immune Deficiency Treatment Consortium's (PIDTC's) prospective and retrospective studies of SCID.

OBJECTIVE

Because of the advent of newborn screening for SCID and expanded availability of genetic sequencing, revision of the PIDTC 2014 Criteria was needed.

METHODS

We developed and tested updated PIDTC 2022 SCID Definitions by analyzing 379 patients proposed for prospective enrollment into Protocol 6901, focusing on the ability to distinguish patients with various SCID subtypes.

RESULTS

According to PIDTC 2022 Definitions, 18 of 353 patients eligible per 2014 Criteria were considered not to have SCID, whereas 11 of 26 patients ineligible per 2014 Criteria were determined to have SCID. Of note, very low numbers of autologous T cells (<0.05 × 109/L) characterized typical SCID under the 2022 Definitions. Pathogenic variant(s) in SCID-associated genes was identified in 93% of patients, with 7 genes (IL2RG, RAG1, ADA, IL7R, DCLRE1C, JAK3, and RAG2) accounting for 89% of typical SCID. Three genotypes (RAG1, ADA, and RMRP) accounted for 57% of cases of leaky/atypical SCID; there were 13 other rare genotypes. Patients with leaky/atypical SCID were more likely to be diagnosed at more than age 1 year than those with typical SCID lacking maternal T cells: 20% versus 1% (P < .001). Although repeat testing proved important, an initial CD3 T-cell count of less than 0.05 × 109/L differentiated cases of typical SCID lacking maternal cells from leaky/atypical SCID: 97% versus 7% (P < .001).

CONCLUSIONS

The PIDTC 2022 Definitions describe SCID and its subtypes more precisely than before, facilitating analyses of SCID characteristics and outcomes.

Adapting the HCT-CI Definitions for Children, Adolescents, and Young Adults with Hematologic Malignancies Undergoing Allogeneic Hematopoietic Cell Transplantation

Allogeneic hematopoietic cell transplantation is a curative procedure for hematologic malignancies but is associated with a significant risk of non-relapse mortality (NRM). The Hematopoietic Cell Transplantation-Comorbidity Index (HCT-CI) is a prognostic tool that discriminates this risk in all age groups. A recent survey of transplant physicians demonstrated that 79% of pediatric providers used the HCT-CI infrequently, and most reported concerns about its applicability in the younger population. We conducted a retrospective study using the Center for International Blood and Marrow Transplant Research database to examine the impact of expanded HCT-CI definitions on NRM in pediatric and young adult patients with hematologic malignancies. We included 5790 patients <40 years old receiving allogeneic transplants between 2008 and 2017 to examine broader definitions of comorbidities in the HCT-CI, including history of mechanical ventilation and fungal infection, estimated glomerular filtration rate, and body mass index (BMI) percentiles. Multivariable Fine-Gray models were created to determine the effect of each HCT-CI defining comorbidity and its modification on NRM and were used to develop 2 novel risk scores. We next developed the expanded HCT-CI for children and young adults (youth with malignancies; expanded ymHCT-CI), where 23% patients had an increased comorbidity score, compared to the HCT-CI. Comorbidities with hazard ratio < 1.2 were then removed to create the simplified HCT-CI for children and young adults (youth with malignancies; simplified ymHCT-CI), which demonstrated higher scores corresponded to a greater risk of NRM (P < .001). These novel comorbidity indexes with broader definitions are more relevant to pediatric and young adult patients, and prospective studies are needed to validate these in the younger patient population. It remains to be seen whether the development of these pediatric-specific and practical risk indexes increases their use by the pediatric transplant community.

Updated Trends in Hematopoietic Cell Transplantation in the United States with an Additional Focus on Adolescent and Young Adult Transplantation Activity and Outcomes

Hematopoietic cell transplantation (HCT) has been successfully used to treat many malignant and nonmalignant conditions. As supportive care, donor selection, and treatment modalities evolve, documenting HCT trends and outcomes is critical. This report from the Center for International Blood and Marrow Transplant Research (CIBMTR) provides an update on current transplantation activity and survival rates in the United States. Additional data on the use and outcomes of HCT in the adolescent and young adult (AYA) population are included. AYA patients more frequently receive peripheral blood stem cell grafts than pediatric patients, which may reflect differences in practice in pediatric versus adult treatment centers. The proportions of donor types also differ those in adult and pediatric populations. Outcomes for patients in the AYA age range are similar to those of pediatric patients for acute myelogenous leukemia but worse for acute lymphoblastic leukemia. Outcomes for both leukemias are better in AYA patients compared with older adults. Comparing the time periods 2000 to 2009 and 2010 to 2019 revealed significant improvement in overall survival across the age spectrum, but the greatest improvement in the AYA age group.

GATA2 deficiency detected by newborn screening for SCID: A case report

The early diagnosis and treatment of inborn errors of immunity (IEI) is crucial in reducing the morbidity and mortality due to these disorders. The institution of newborn screening (NBS) for the diagnosis of Severe Combined Immune Deficiency (SCID) has decreased the mortality of this disorder and led to the discovery of novel genetic defects that cause this disease. GATA2 deficiency is an autosomal dominant, pleiotropic disease with clinical manifestations that include bone marrow failure, monocyte and B cell deficiency, leukemia, pulmonary alveolar proteinosis and lymphedema. We present the case of an infant identified by newborn screening for SCID due to GATA2 deficiency.

Diagnostic work-up for severe aplastic anemia in children: Consensus of the North American Pediatric Aplastic Anemia Consortium

The North American Pediatric Aplastic Anemia Consortium (NAPAAC) is a group of pediatric hematologist-oncologists, hematopathologists, and bone marrow transplant physicians from 46 institutions in North America with interest and expertise in aplastic anemia, inherited bone marrow failure syndromes, and myelodysplastic syndromes. The NAPAAC Bone Marrow Failure Diagnosis and Care Guidelines Working Group was established with the charge of harmonizing the approach to the diagnostic workup of aplastic anemia in an effort to standardize best practices in the field. This document outlines the rationale for initial evaluations in pediatric patients presenting with signs and symptoms concerning for severe aplastic anemia.

Return-to-School Practices for Pediatric Hematopoietic Cell Transplantation Recipients during the COVID-19 Pandemic

Although organizations such as Centers for Disease Control and Prevention and American Academy of Pediatrics have published guidelines favoring the resumption of in-person schooling during the coronavirus disease 19 (COVID-19) pandemic, there is no specific guidance on hematopoietic cell transplantation (HCT) recipients' safe return to school. We conducted a cross-sectional survey of pediatric HCT physician members of the Pediatric Transplantation and Cellular Therapy Consortium practicing in the United States to describe current return-to-school practices during the COVID-19 pandemic for HCT recipients. A total of 122 respondents (response rate, 30.6%) from 60 transplant centers in 32 US states completed the survey. Most of the respondents (76%) recommended that HCT recipients consider a remote or hybrid school option at this time if possible. If not possible, the respondents recommended a return to in-person school if the patient is at least 12 months post-transplantation or off immune suppression, while taking school safety measures and local COVID-19 cases into account. These results provide valuable guidance for the HCT community, patients, and caregivers on important topics to consider while making return-to-school decisions.

Delirium in Children Undergoing Hematopoietic Cell Transplantation: A Multi-Institutional Point Prevalence Study

Introduction: Delirium occurs frequently in adults undergoing hematopoietic cell transplantation, with significant associated morbidity. Little is known about the burden of delirium in children in the peri-transplant period. This study was designed to determine delirium rates, define risk factors (demographic and treatment related), and establish feasibility of multi-institutional bedside screening for delirium in children undergoing hematopoietic cell transplant. Methods: This is a multi-institutional point prevalence study. All subjects were prospectively screened for delirium twice daily using the Cornell Assessment of Pediatric Delirium over a 10-day period. De-identified data, including basic demographics and daily characteristics, were extracted from the electronic medical record. Results: Eleven North American institutions were included, 106 children were enrolled, and 883 hospital days were captured. Delirium screening was successfully completed on more than 98% of the study days. Forty-eight children (45%) developed delirium over the course of the 10-day study. Children were diagnosed with delirium on 161/883 study days, for an overall delirium rate of 18% per day. Higher delirium rates were noted in children <5 years old (aOR 0.41 for children over 5 years), and in association with specific medications (melatonin, steroids, and tacrolimus). Conclusion: Delirium was a frequent occurrence in our study cohort, with identifiable risk factors. Delirium screening is highly feasible in the pediatric hematopoietic cell transplant patient population. A large-scale prospective longitudinal study following children throughout their transplant course is urgently needed to fully describe the epidemiology of pediatric delirium, explore the effects of delirium on patient outcomes, and establish guidelines to prevent and treat delirium in the peri-transplant period.

Length of Stay and Health Care Utilization Among Pediatric Autologous Hematopoietic Cell Transplantation Recipients

Autologous hematopoietic cell transplantation (autoHCT) has become a critical component in the treatment of pediatric malignancies, allowing for high-dose chemotherapy to be given safely and with greater efficacy in a subset of children at high risk for relapse. Risk factors associated with hospital length of stay (LOS) in adults undergoing autoHCT have been studied extensively; however, there is a paucity of studies describing risk factors associated with LOS and health care cost in children undergoing autoHCT. This study sought to identify factors influencing LOS and cost in pediatric autoHCT. We assessed LOS from autologous stem cell infusion from day 0 (D0) in 100 autoHCT admissions in 73 patients with malignant disease between 2007 and 2019. We evaluated demographic, pre-transplantation, post-transplantation, and socioeconomic variables to identify potential risk factors associated with LOS and cost. AutoHCT cost data were provided by the Pediatric Health Information System database. Indications for autoHCT included neuroblastoma (35.6%), brain tumor (27.4%), and relapsed lymphoma (24.7%). The median patient age was 4.88 years (range, 0.72 to 22 years), with 71% age <12 years, and the cohort was 63% male, 77% white, and 41% Hispanic. The median LOS from D0 was 19 days (range, 13 to 100 days). On multivariable analysis, age >12 years compared with 2 to 12 years (estimate, -8.9 days; 95% confidence interval [CI], -15.1 to -2.8; P = .004) and complete remission/very good partial response disease status (estimate, -5.0 days; 95% CI, -9.6 to -0.4 days; P = .031) were associated with a significantly decreased median LOS, whereas Hispanic ethnicity (estimate, +6.8 days; 95% CI, 1.1 to 12.6 days; P = .019), >5 days of fever (estimate, +7.3 days; 95% CI, 1.4 to 13.2 days; P = .015), and pediatric intensive care unit (PICU) LOS (estimate, +14.9 days; 95% CI, 1.8 to 28.0 days; P = .025) were associated with a significant increase in median LOS. The median cost per transplantation admission was $96,850 (range, $39,833 to $587,321). Multivariable analysis showed that age >12 years (estimate, -$6,776; 95% CI, -$71,787 to -$11,402; P = .007) or <2 years (estimate, -$32,426; 95% CI, -$53,507 to -$11,345; P = .003), and complete remission/very good partial response disease status (estimate, -$20,266; 95% CI, -$40,211 to -$322; P = .046) were associated with significantly decreased median cost, whereas >5 days of fever (estimate, +$58,886; 95% CI, $30,667 to $87,105; P < .001) and PICU admission (estimate, +$102,458; 95% CI, $23,843 to $181,076; P = .011) were associated with significantly increased median cost. In summary, fever and PICU stay were found to be risk factors for increased LOS and cost. Age <12 years and Hispanic ethnicity were risk factors for increased LOS, whereas age <2 years and >12 years and female sex were associated with decreased cost. Further investigation to determine specific factors influencing LOS and cost is warranted to identify potentially modifiable risks within these patient populations.

Multisystem Inflammatory Syndrome in Children Associated With Coronavirus Disease 2019 in a Children's Hospital in New York City: Patient Characteristics and an Institutional Protocol for Evaluation, Management, and Follow-Up

OBJECTIVES

The disease caused by severe acute respiratory syndrome coronavirus 2, known as coronavirus disease 2019, has resulted in a global pandemic. Reports are emerging of a new severe hyperinflammatory syndrome related to coronavirus disease 2019 in children and adolescents. The Centers for Disease Control and Prevention has designated this disease multisystem inflammatory syndrome in children. Our objective was to develop a clinical inpatient protocol for the evaluation, management, and follow-up of patients with this syndrome.

DATA SOURCES

The protocol was developed by a multidisciplinary team based on relevant literature related to coronavirus disease 2019, multisystem inflammatory syndrome in children, and related inflammatory syndromes, as well as our experience caring for children with multisystem inflammatory syndrome in children. Data were obtained on patients with multisystem inflammatory syndrome in children at our institution from the pre-protocol and post-protocol periods.

DATA SYNTHESIS

Our protocol was developed in order to identify cases of multisystem inflammatory syndrome in children with high sensitivity, stratify risk to guide treatment, recognize co-infectious or co-inflammatory processes, mitigate coronary artery abnormalities, and manage hyperinflammatory shock. Key elements of evaluation include case identification using broad clinical characteristics and comprehensive laboratory and imaging investigations. Treatment centers around glucocorticoids and IV immunoglobulin with biologic immunomodulators as adjuncts. Multidisciplinary follow-up after discharge is indicated to manage continued outpatient therapy and evaluate for disease sequelae. In nearly 2 months, we admitted 54 patients with multisystem inflammatory syndrome in children, all of whom survived without the need for invasive ventilatory or mechanical circulatory support. After institution of this protocol, patients received earlier treatment and had shorter lengths of hospital stay.

CONCLUSIONS

This report provides guidance to clinicians on evaluation, management, and follow-up of patients with a novel hyperinflammatory syndrome related to coronavirus disease 2019 known as multisystem inflammatory syndrome in children. It is based on the relevant literature and our experience. Instituting such a protocol during a global pandemic is feasible and is associated with patients receiving treatment and returning home more quickly.

Impact of Pretransplantation Renal Dysfunction on Outcomes after Allogeneic Hematopoietic Cell Transplantation

Renal dysfunction is a recognized risk factor for mortality after allogeneic hematopoietic cell transplantation (alloHCT), yet our understanding of the effect of different levels of renal dysfunction at time of transplantation on outcomes remains limited. This study explores the impact of different degrees of renal dysfunction on HCT outcomes and examines whether the utilization of incremental degrees of renal dysfunction based on estimated glomerular filtration rate (eGFR) improve the predictability of the hematopoietic cell transplantation comorbidity index (HCT-CI). The study population included 2 cohorts: cohort 1, comprising patients age ≥40 years who underwent alloHCT for treatment of hematologic malignancies between 2008 and 2016 (n = 13,505; cohort selected given a very low incidence of renal dysfunction in individuals age <40 years), and cohort 2, comprising patients on dialysis at the time of HCT (n = 46). eGFR was measured using the Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) method. The patients in cohort 1 were assigned into 4 categories-eGFR ≥90 mL/min (n = 7062), eGFR 60 to 89 mL/min (n = 5264), eGFR 45 to 59 mL/min (n = 897), and eGFR <45 mL/min (n=282)-to assess the impact of degree of renal dysfunction on transplantation outcomes. Transplantation outcomes in patients on dialysis at the time of alloHCT were analyzed separately. eGFR <60 mL/min was associated with an increased risk for nonrelapse mortality (NRM) and requirement for dialysis post-HCT. Compared with the eGFR ≥90 group, the hazard ratio (HR) for NRM was 1.46 (P = .0001) for the eGFR 45 to 59 mL/min group and 1.74 (P = .004) for the eGFR <45 mL/min group. Compared with the eGFR ≥90 mL/min group, the eGFR 45 to 59 mL/min group (HR, 2.45; P < .0001) and the eGFR <45 mL/min group (HR, 3.09; P < .0001) had a higher risk of renal failure necessitating dialysis after alloHCT. In addition, eGFR <45 mL/min was associated with an increased overall mortality (HR, 1.63; P < .0001). An eGFR-based revised HCT-CI was also developed and shown to be predictive of overall survival (OS) and NRM, with predictive performance similar to the original HCT-CI. Among 46 patients on dialysis at alloHCT, the 1-year probability of OS was 20%, and that of NRM was 67%. The degree of pretransplantation renal dysfunction is an independent predictor of OS, NRM, and probability of needing dialysis after alloHCT. An eGFR-based HCT-CI is a validated index for predicting outcomes in adults with hematologic malignancies undergoing alloHCT. The outcomes of alloHCT recipients on dialysis are dismal; therefore, one should strongly weigh the significant risks of being on hemodialysis as a factor in determining alloHCT candidacy.

Infection prophylaxis patterns following pediatric autologous hematopoietic stem cell transplantation: A survey of Pediatric Transplant and Cell Therapy Consortium centers

No standardized guidelines exist for infectious prophylaxis following pediatric auto-HSCT. We hypothesized significant variation in clinical practice. Thirty-three Pediatric Transplant and Cell Therapy Consortium centers completed a survey to assess institutional management. The majority utilize viral (91%) and fungal prophylaxis (94%), but duration varies. Bacterial prophylaxis during neutropenia is instituted by 42%. Our study demonstrates marked practice variability in infectious prophylaxis across centers. Additional research is needed to address patterns of infectious complications and to develop meaningful clinical practice guidelines for pediatric auto-HSCT.

Eculizumab treatment for renal failure in a pediatric patient with COVID-19

While there are increasing reports of acute kidney injury among hospitalized adults with COVID-19, there is still limited information on renal complications associated with COVID-19 in children. The cause of kidney involvement in COVID-19 is likely multifactorial, and appears to involve a complex process, including complement dysregulation and thrombotic microangiopathy. We present a pediatric case of COVID-19 and renal failure due to thombotic microangiopathy, successfully treated with eculizumab.

Subsequent neoplasms and late mortality in children undergoing allogeneic transplantation for nonmalignant diseases

We examined the risk of subsequent neoplasms (SNs) and late mortality in children and adolescents undergoing allogeneic hematopoietic cell transplantation (HCT) for nonmalignant diseases (NMDs). We included 6028 patients (median age, 6 years; interquartile range, 1-11; range, <1 to 20) from the Center for International Blood and Marrow Transplant Research (1995-2012) registry. Standardized mortality ratios (SMRs) in 2-year survivors and standardized incidence ratios (SIRs) were calculated to compare mortality and SN rates with expected rates in the general population. Median follow-up of survivors was 7.8 years. Diagnoses included severe aplastic anemia (SAA; 24%), Fanconi anemia (FA; 10%), other marrow failure (6%), hemoglobinopathy (15%), immunodeficiency (23%), and metabolic/leukodystrophy syndrome (22%). Ten-year survival was 93% (95% confidence interval [95% CI], 92% to 94%; SMR, 4.2; 95% CI, 3.7-4.8). Seventy-one patients developed SNs (1.2%). Incidence was highest in FA (5.5%), SAA (1.1%), and other marrow failure syndromes (1.7%); for other NMDs, incidence was <1%. Hematologic (27%), oropharyngeal (25%), and skin cancers (13%) were most common. Leukemia risk was highest in the first 5 years posttransplantation; oropharyngeal, skin, liver, and thyroid tumors primarily occurred after 5 years. Despite a low number of SNs, patients had an 11-fold increased SN risk (SIR, 11; 95% CI, 8.9-13.9) compared with the general population. We report excellent long-term survival and low SN incidence in an international cohort of children undergoing HCT for NMDs. The risk of SN development was highest in patients with FA and marrow failure syndromes, highlighting the need for long-term posttransplantation surveillance in this population.

Hemophagocytic lymphohistiocytosis mimicking neonatal hemochromatosis

Hemophagocytic lymphohistiocytosis (HLH) is a potentially fatal illness characterized by impaired natural killer (NK) cell and cytotoxic T-cell function. Patients develop systemic inflammation, multisystem organ dysfunction, and if untreated, death. Patients who present in the neonatal period often have atypical presentations with evidence of liver dysfunction and cholestasis; this has a broad differential diagnosis including neonatal infection, congenital liver defects, or other causes of liver dysfunction, such as neonatal hemochromatosis. Here, we present an infant whose diagnosis of familial HLH was confounded by the history of a stillborn sibling with suspected neonatal hemochromatosis, ultimately delaying diagnosis and initiation of curative treatment. This highlights the need to maintain a low threshold for sending HLH work-up concurrently with evaluation of liver diseases in infants with liver dysfunction, to ensure timely diagnosis and initiation of treatment. Clinicians should maintain a high index of suspicion for HLH and be aware that HLH may mimic the findings on liver biopsy seen in neonatal hemochromatosis.

Pulmonary Complications in Pediatric and Adolescent Patients Following Allogeneic Hematopoietic Cell Transplantation

Pulmonary complications after hematopoietic cell transplantation (HCT) can lead to significant morbidity and mortality. Limited evaluation of the true incidence of these complications in children and subsequent outcomes of these complications have not been evaluated recently. In April 2018, the National Heart, Lung, and Blood Institute; the Eunice Kennedy Shriver National Institute of Child Health and Human Development; and the National Cancer Institute cosponsored a meeting of experts to describe the status of pulmonary complications in children after HCT, identify critical gaps in knowledge, and explore avenues for research to advance care and optimize outcomes. The Center for International Blood and Marrow Transplant Research was used to evaluate the cumulative incidence of pulmonary complications in children and their respective survival. Of the 5022 children included in this analysis who received allogeneic HCT from 2010 to 2016, 606 developed pulmonary complications within the first year after HCT. Pneumonitis occurred in 388 patients, 125 patients developed pulmonary hemorrhage, and 200 patients had lung graft-versus-host disease (GVHD). For those developing pulmonary complications within 1 year, overall survival 100 days after diagnosis of pulmonary complications was 49% (95% confidence interval [CI], 43% to 54%) for patients with pneumonitis, 23% (95% CI, 16% to 31%) in patients with pulmonary hemorrhage, and 87% (95% CI, 81% to 91%) in patients with pulmonary GVHD. This study demonstrates the approximate incidence of these complications, as well as their significant effects on survival, and can serve as a baseline for future research.

Checkpoint inhibition of PD-L1 and CTLA-4 in a child with refractory acute leukemia

Children with multiple relapsed or refractory leukemia have dismal survival. Research has identified engagement of immune checkpoint receptors (e.g., PD-1, PD-L1 and CTLA-4) as a mechanism for treatment resistance. For adult cancer, inhibitors of PD-1 (nivolumab) and CTLA-4 (ipilimumab) have shown promise with response rates ranging from 7 to 40%. In vitro studies using acute myeloid leukemia cell lines have shown that acute myeloid leukemia blasts may similarly utilize the PD-1/PD-L1 axis to evade an anticancer immune response. We report the first case of a pediatric patient with multiple relapsed/refractory leukemia treated with nivolumab, ipilimumab and 5-azacytidine who tolerated therapy with brief improvement of symptoms.

Outcomes after Second Hematopoietic Cell Transplantation in Children and Young Adults with Relapsed Acute Leukemia

Children with acute leukemia who relapse after hematopoietic cell transplantation (HCT) have few therapeutic options. We studied 251 children and young adults with acute myelogenous or lymphoblastic leukemia who underwent a second HCT for relapse after their first HCT. The median age at second HCT was 11 years, and the median interval between first and second HCT was 17 months. Most of the patients (n = 187; 75%) were in remission, received a myeloablative conditioning regimen (n = 157; 63%), and underwent unrelated donor HCT (n = 230; 92%). The 2-year probability of leukemia-free survival (LFS) was 33% after transplantation in patients in remission, compared with 19% after transplantation in patients not in remission (P = .02). The corresponding 8-year probabilities were 24% and 10% (P = .003). A higher rate of relapse contributed to the difference in LFS. The 2-year probability of relapse after transplantation was 42% in patients in remission and 56% in those in relapse (P = .05). The corresponding 8-year probabilities were 49% and 64% (P = .04). These data extend the findings of others showing that patients with a low disease burden are more likely to benefit from a second transplantation. Late relapse led to a 10% decrement in LFS beyond the second year after second HCT. This differs from first HCT, in which most relapses occur within 2 years after HCT.

First report that prior ECMO therapy does not preclude hematopoietic cell transplantation

Hematopoietic stem cell transplantation (HCT) offers a potential cure for patients with high-risk malignancies but carries a risk of death from transplant-related complications. Extracorporeal membrane oxygenation (ECMO) is often considered a contraindication to transplant with the assumption that lung injury puts the patient at risk for pulmonary complications post-HCT. Although patients who have required prolonged intubation show gradual improvement in pulmonary function over time, there is little data on pulmonary functional recovery after ECMO which makes assessment pre-HCT difficult. We present a case series of two patients with high-risk hematologic malignancies, who had previously received ECMO and then underwent reduced-intensity HCT. Although both patients had complications post-HCT, neither patient suffered significant pulmonary toxicity related to their prior ECMO exposure. We conclude that, although patients who have previously been treated with ECMO remain at high risk for complications after transplant, but they should not be excluded from consideration for reduced intensity transplantation.

Fecal calprotectin and serum albumin as markers of gastrointestinal graft versus host disease

BACKGROUND

Acute graft versus host disease (aGVHD) affects approximately 30-60% of patients after allogeneic hematopoietic stem cell transplantation (HCT) and our ability to predict who develops this complication and their response to treatment is limited. Fecal calprotectin has recently gained popularity as an effective marker of GI inflammation in patients with Inflammatory Bowel Disease (IBD).

METHODS

Fecal calprotectin and albumin were evaluated as prognostic and predictive markers of aGVHD in 60 adult and pediatric HCT patients. Stool samples were sent for calprotectin quantification prior to starting conditioning, at day 14 post-HCT, at day 28 post-HCT, and at onset of aGVHD ± 2 days.

RESULTS

Fecal calprotectin did not differentiate patients with GI-GVHD and non-GI GVHD and did not vary based on severity. However, in patients with steroid-refractory GI aGVHD, significantly higher fecal calprotectin levels were noted. At onset of lower-GI symptoms, steroid refractory patients (n = 3) had a mean fecal calprotectin level of 449 ug/g (range 116-1111 ug/g) and a mean albumin of 1.93 g/dL (range 1.6-2.3 g/dL) compared with a mean fecal calprotectin of 24 ug/g (range 16-31 ug/g) and a mean albumin of 3.3 g/dL (range 2.3-3.9 g/dL) in steroid responsive patients (n = 9) (fecal calprotectin p = 0.032, albumin p = 0.027).

CONCLUSION

Patients with steroid-refractory GI aGVHD had higher fecal calprotectin levels and lower albumin levels than patients with steroid-responsive disease. We recommend further studies to evaluate non-invasive tests with fecal calprotectin in combination with albumin in predicting steroid refractory disease at onset of symptoms to potentially identify patients that may benefit from upfront escalation in GVHD treatment.

TP53 Haploinsufficiency Rescues Emergency Granulopoiesis in FANCC-/- Mice

Emergency (stress) granulopoiesis is an episodic process for the production of granulocytes in response to infectious challenge. We previously determined that Fanconi C, a component of the Fanconi DNA-repair pathway, is necessary for successful emergency granulopoiesis. Fanconi anemia results from mutation of any gene in this pathway and is characterized by bone marrow failure (BMF) in childhood and clonal progression in adolescence. Although murine Fanconi anemia models exhibit relatively normal steady-state hematopoiesis, FANCC^-/- mice are unable to mount an emergency granulopoiesis response. Instead, these mice develop BMF and die during repeated unsuccessful emergency granulopoiesis attempts. In FANCC^-/- mice, BMF is associated with extensive apoptosis of hematopoietic stem and progenitor cells through an undefined mechanism. In this study, we find that TP53 haploinsufficiency completely rescues emergency granulopoiesis in FANCC^-/- mice and protects them from BMF during repeated emergency granulopoiesis episodes. Instead, such recurrent challenges accelerated clonal progression in FANCC^-/-TP53^+/- mice. In FANCC^-/- mice, BMF during multiple emergency granulopoiesis attempts was associated with increased ataxia telangiectasia and Rad3-related protein (Atr) and p53 activation with each attempt. In contrast, we found progressive attenuation of expression and activity of Atr, and consequent p53 activation and apoptosis, in the bone marrow of FANCC^-/-TP53^+/- mice during this process. Therefore, activation of Atr-with consequent Fanconi-mediated DNA repair or p53-dependent apoptosis-is an essential component of emergency granulopoiesis and it protects the bone marrow from genotoxic stress during this process.