Posttransplant cyclophosphamide is associated with increased cytomegalovirus infection: a CIBMTR analysis.

Prior studies suggest increased cytomegalovirus (CMV) infection after haploidentical donor transplantation with posttransplant cyclophosphamide (HaploCy). The role of allograft source and posttransplant cyclophosphamide (PTCy) in CMV infection is unclear. We analyzed the effect of graft source and PTCy on incidence of CMV infection, and effects of serostatus and CMV infection on transplant outcomes. We examined patients reported to the Center for International Blood and Marrow Transplantation Research between 2012 and 2017 who had received HaploCy (n = 757), matched related (Sib) with PTCy (SibCy, n = 403), or Sib with calcineurin inhibitor-based prophylaxis (SibCNI, n = 1605). Cumulative incidences of CMV infection by day 180 were 42%, 37%, and 23%, respectively (P < .001). CMV disease was statistically comparable. CMV infection risk was highest for CMV-seropositive recipients (R+), but significantly higher in PTCy recipients regardless of donor (HaploCy [n = 545]: hazard ratio [HR], 50.3; SibCy [n = 279]: HR, 47.7; SibCNI [n = 1065]: HR, 24.4; P < .001). D+/R- patients also had increased risk for CMV infection. Among R+ or those developing CMV infection, HaploCy had worse overall survival and nonrelapse mortality. Relapse was unaffected by CMV infection or serostatus. PTCy was associated with lower chronic graft-versus-host disease (GVHD) overall, but CMV infection in PTCy recipients was associated with higher chronic GVHD (P = .006). PTCy, regardless of donor, is associated with higher incidence of CMV infection, augmenting the risk of seropositivity. Additionally, CMV infection may negate the chronic GVHD protection of PTCy. This study supports aggressive prevention strategies in all receiving PTCy.

Financial burden and recommended multilevel solutions among caregivers of pediatric hematopoietic stem cell transplant recipients.

BACKGROUND: The healthcare costs of patients who receive hematopoietic stem cell transplantation (HSCT) are substantial. At the same time, the increasing use of pediatric HSCT leaves more caregivers of pediatric HSCT recipients at risk for financial burden-an understudied area of research. METHODS: Financial burden experienced by caregivers of recipients who received autologous or allogeneic transplants was assessed using an explanatory mixed-methods design including a one-time survey and semi-structured interviews. Financial burden was assessed through an adapted COmprehensive Score for financial Toxicity (COST) as well as questions about the types of out-of-pocket costs and cost-coping behaviors. Chi-squared or Fisher's exact tests were used to assess differences in costs incurred and coping behaviors by financial toxicity and financial toxicity by demographic factors. Interviews were audio recorded, transcribed, and analyzed using directed content analysis. RESULTS: Of 99 survey participants, 64% experienced high financial toxicity (COST  ≤ $ \le \;$ 22). Caregivers with high financial toxicity were more likely to report costs related to transportation and diet. High financial toxicity was associated with nearly all cost-coping behaviors (e.g., borrowed money). High financial toxicity was also associated with increased use of hospital financial support and transportation assistance. Qualitative analysis resulted in four categories that were integrated with quantitative findings: (1) care-related out-of-pocket costs incurred, (2) cost-coping behaviors, (3) financial support resources used, and (4) multilevel recommendations for reducing financial burden. CONCLUSIONS: Considering the substantial, long-term financial burden among pediatric HSCT patients and their caregivers, this population would benefit from adapted and tailored financial burden interventions.

DNA Sequencing to Detect Residual Disease in Adults With Acute Myeloid Leukemia Prior to Hematopoietic Cell Transplant.

Importance: Preventing relapse for adults with acute myeloid leukemia (AML) in first remission is the most common indication for allogeneic hematopoietic cell transplant. The presence of AML measurable residual disease (MRD) has been associated with higher relapse rates, but testing is not standardized. Objective: To determine whether DNA sequencing to identify residual variants in the blood of adults with AML in first remission before allogeneic hematopoietic cell transplant identifies patients at increased risk of relapse and poorer overall survival compared with those without these DNA variants. Design, Setting, and Participants: In this retrospective observational study, DNA sequencing was performed on pretransplant blood from patients aged 18 years or older who had undergone their first allogeneic hematopoietic cell transplant during first remission for AML associated with variants in FLT3, NPM1, IDH1, IDH2, or KIT at 1 of 111 treatment sites from 2013 through 2019. Clinical data were collected, through May 2022, by the Center for International Blood and Marrow Transplant Research. Exposure: Centralized DNA sequencing of banked pretransplant remission blood samples. Main Outcomes and Measures: The primary outcomes were overall survival and relapse. Day of transplant was considered day 0. Hazard ratios were reported using Cox proportional hazards regression models. Results: Of 1075 patients tested, 822 had FLT3 internal tandem duplication (FLT3-ITD) and/or NPM1 mutated AML (median age, 57.1 years, 54% female). Among 371 patients in the discovery cohort, the persistence of NPM1 and/or FLT3-ITD variants in the blood of 64 patients (17.3%) in remission before undergoing transplant was associated with worse outcomes after transplant (2013-2017). Similarly, of the 451 patients in the validation cohort who had undergone transplant in 2018-2019, 78 patients (17.3%) with residual NPM1 and/or FLT3-ITD variants had higher rates of relapse at 3 years (68% vs 21%; difference, 47% [95% CI, 26% to 69%]; HR, 4.32 [95% CI, 2.98 to 6.26]; P < .001) and decreased survival at 3 years (39% vs 63%; difference, -24% [2-sided 95% CI, -39% to -9%]; HR, 2.43 [95% CI, 1.71 to 3.45]; P < .001). Conclusions and Relevance: Among patients with acute myeloid leukemia in first remission prior to allogeneic hematopoietic cell transplant, the persistence of FLT3 internal tandem duplication or NPM1 variants in the blood at an allele fraction of 0.01% or higher was associated with increased relapse and worse survival compared with those without these variants. Further study is needed to determine whether routine DNA-sequencing testing for residual variants can improve outcomes for patients with acute myeloid leukemia.

Understanding the financial and psychological impact of employment disruption among caregivers of pediatric HSCT recipients: a mixed methods analysis.

PURPOSE: Pediatric hematopoietic stem cell transplantation (HSCT) confers a substantial financial burden onto patients' families. In addition to high direct medical costs, HSCTs typically require at least one caregiver to take time away from work or other responsibilities, often leading to reduced household income. Using mixed methods, we sought to understand the impact of pediatric HSCT on caregiver employment and financial need. METHODS: We surveyed caregivers of living pediatric patients who underwent HSCT at one of two southeastern transplant centers between 2012 and 2018 (N = 95). We then interviewed a subset of caregivers (N = 18) to understand whether and how employment disruption contributed to financial distress. RESULTS: Among caregivers surveyed, the majority of household wage earners changed their work schedules to attend medical appointments and missed workdays. This resulted in income loss for 87% of families, with 31% experiencing an income reduction of over 50%. Qualitative interviews pointed to four emergent themes: (1) employment disruption exacerbated existing financial challenges; (2) parental division of labor between caregiving and providing financially led to heightened psychological distress; (3) existing employment leave and protection resources were essential but not sufficient; and (4) the ability to work remotely and having a supportive employer facilitated employment maintenance throughout the HSCT process. CONCLUSION: Expanded employment protections and access to accommodations are needed to limit the impact of HSCT on household income, health insurance, and financial hardship. Additionally, interventions are needed to ensure caregivers are equipped with the information necessary to navigate conversations with employers and prepare for the financial and psychological reality of employment disruption.

A Phase II Randomized Clinical Trial of the Safety and Efficacy of Intravenous Umbilical Cord Blood Infusion for Treatment of Children with Autism Spectrum Disorder.

OBJECTIVE: To evaluate whether umbilical cord blood (CB) infusion is safe and associated with improved social and communication abilities in children with autism spectrum disorder (ASD). STUDY DESIGN: This prospective, randomized, placebo-controlled, double-blind study included 180 children with ASD, aged 2-7 years, who received a single intravenous autologous (n = 56) or allogeneic (n = 63) CB infusion vs placebo (n = 61) and were evaluated at 6 months postinfusion. RESULTS: CB infusion was safe and well tolerated. Analysis of the entire sample showed no evidence that CB was associated with improvements in the primary outcome, social communication (Vineland Adaptive Behavior Scales-3 [VABS-3] Socialization Domain), or the secondary outcomes, autism symptoms (Pervasive Developmental Disorder Behavior Inventory) and vocabulary (Expressive One-Word Picture Vocabulary Test). There was also no overall evidence of differential effects by type of CB infused. In a subanalysis of children without intellectual disability (ID), allogeneic, but not autologous, CB was associated with improvement in a larger percentage of children on the clinician-rated Clinical Global Impression-Improvement scale, but the OR for improvement was not significant. Children without ID treated with CB showed significant improvements in communication skills (VABS-3 Communication Domain), and exploratory measures including attention to toys and sustained attention (eye-tracking) and increased alpha and beta electroencephalographic power. CONCLUSIONS: Overall, a single infusion of CB was not associated with improved socialization skills or reduced autism symptoms. More research is warranted to determine whether CB infusion is an effective treatment for some children with ASD.

Pediatric Aggressive Mature B-Cell Lymphomas, Version 2.2020, NCCN Clinical Practice Guidelines in Oncology.

Pediatric aggressive mature B-cell lymphomas are the most common types of non-Hodgkin lymphoma in children, and they include Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL). These diseases are highly aggressive but curable, the treatment is complex, and patients may have many complicated supportive care issues. The NCCN Guidelines for Pediatric Aggressive Mature B-Cell Lymphomas provide guidance regarding pathology and diagnosis, staging, initial treatment, disease reassessment, surveillance, therapy for relapsed/refractory disease, and supportive care for clinicians who treat sporadic pediatric BL and DLBCL.

The challenge of long-term follow-up of survivors of childhood acute leukemia after hematopoietic stem cell transplantation in resource-limited countries: A single-center report from Brazil.

With the number of long-term HSCT survivors steadily increasing, attention needs to be focused on the late complications and quality of life. We therefore analyzed the outcome of 101 pediatric patients (<18 years old at the time of HSCT) transplanted for acute leukemia between 1981 and 2015 at Complexo Hospital de Clínicas, Federal University of Paraná, Brazil, and who survived at least two years after HSCT. The median follow-up was 5.9 years (2.0-29.0); median age at follow-up was 17.5 years (2.98-39.0). The 5-year cumulative incidence of relapse was 27.5% (95% CI 18.6%-36.4%). Two-year cumulative incidence of chronic GVHD was 21.8% (95% CI 13.7%-29.8%). Of the 101 patients, 72 patients (71.3%) presented with late effects. Those surviving longer after HSCT experienced more complications. Patients who received TBI-based regimen developed more late effects (P = .013) and more endocrinological complications (P = .024). Endocrinological complications were the most common late sequelae found in this study. For childhood survivors, quality of life was not influenced by age (at HSCT or at last visit), time from HSCT, gender, donor, or GVHD. For survivors that no longer were children, only age at last visit impacted financial domain measures, irrespective of gender, donor, or GVHD. The current study confirms the high burden late complications after pediatric HSCT have on the survivors and underlines the importance of extended follow-up.

Reduction in Mortality after Umbilical Cord Blood Transplantation in Children Over a 20-Year Period (1995-2014).

Infections and graft-versus-host disease (GVHD) have historically resulted in high mortality among children undergoing umbilical cord blood transplantation (UCBT). However, recent advances in clinical practice have likely improved outcomes of these patients. We conducted a retrospective cohort study of children (<18years of age) undergoing UCBT at Duke University between January 1, 1995 and December 31, 2014. We compared 2-year all-cause and cause-specific mortality during 3 time periods based on year of transplantation (1995 to 2001, 2002 to 2007, and 2008 to 2014). We used multivariable Cox regression to identify demographic and UCBT characteristics that were associated with all-cause mortality, transplantation-related mortality, and death from invasive aspergillosis after adjustment for time period. During the 20-year study period 824 children underwent UCBT. Two-year all-cause mortality declined from 48% in 1995 to 2001 to 30% in 2008 to 2014 (P = .0002). White race and nonmalignant UCBT indications were associated with lower mortality. Black children tended to have a higher risk of death for which GVHD (18% versus 11%; P = .06) or graft failure (9% versus 3%; P = .01) were contributory than white children. Comparing 2008 to 2014 with 1995 to 2001, more than half (59%) of the reduced mortality was attributable to a reduction in infectious mortality, with 45% specifically related to reduced mortality from invasive aspergillosis. Antifungal prophylaxis with voriconazole was associated with lower mortality from invasive aspergillosis than low-dose amphotericin B lipid complex (hazard ratio, .09; 95% confidence interval, .01 to .76). With the decline in mortality from invasive aspergillosis, adenovirus and cytomegalovirus have become the most frequentinfectious causes of death in children after UCBT. Advances in clinical practice over the past 20years improved survival of children after UCBT. Reduced mortality from infections, particularly invasive aspergillosis, accounted for the largest improvement in survival and was associated with use of voriconazole for antifungal prophylaxis.

Hematopoietic Stem Cell Transplantation to Treat Leukodystrophies: Clinical Practice Guidelines from the Hunter's Hope Leukodystrophy Care Network.

The leukodystrophies are a heterogeneous group of inherited diseases characterized by progressive demyelination of the central nervous system leading to devastating neurologic symptoms and premature death. Hematopoietic stem cell transplantation (HSCT) has been successfully used to treat certain leukodystrophies, including adrenoleukodystrophy, globoid leukodystrophy (Krabbe disease), and metachromatic leukodystrophy, over the past 30 years. To date, these complex patients have primarily been transplanted at a limited number of pediatric centers. As the number of cases identified through pregnancy and newborn screening is increasing, additional centers will be required to treat these children. Hunter's Hope created the Leukodystrophy Care Network in part to create and standardize high-quality clinical practice guidelines to guide the care of affected patients. In this report the clinical guidelines for the care of pediatric patients with leukodystrophies undergoing treatment with HSCT are presented. The initial transplant evaluation, determination of patient eligibility, donor selection, conditioning, supportive care, and post-transplant follow-up are discussed. Throughout these guidelines the need for early detection and treatment and the role of the partnership between families and multidisciplinary providers are emphasized.

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.

Characteristics of Late Fatal Infections after Allogeneic Hematopoietic Cell Transplantation.

We analyzed late fatal infections (LFIs) in allogeneic stem cell transplantation (HCT) recipients reported to the Center for International Blood and Marrow Transplant Research. We analyzed the incidence, infection types, and risk factors contributing to LFI in 10,336 adult and 5088 pediatric subjects surviving for ≥2 years after first HCT without relapse. Among 2245 adult and 377 pediatric patients who died, infections were a primary or contributory cause of death in 687 (31%) and 110 (29%), respectively. At 12 years post-HCT, the cumulative incidence of LFIs was 6.4% (95% confidence interval [CI], 5.8% to 7.0%) in adults, compared with 1.8% (95% CI, 1.4% to 2.3%) in pediatric subjects; P < .001). In adults, the 2 most significant risks for developing LFI were increasing age (20 to 39, 40 to 54, and ≥55 years versus 18 to 19 years) with hazard ratios (HRs) of 3.12 (95% CI, 1.33 to 7.32), 3.86 (95% CI, 1.66 to 8.95), and 5.49 (95% CI, 2.32 to 12.99) and a history of chronic graft-versus-host disease GVHD (cGVHD) with ongoing immunosuppression at 2 years post-HCT compared with no history of GVHD with (HR, 3.87; 95% CI, 2.59 to 5.78). In pediatric subjects, the 3 most significant risks for developing LFI were a history of cGVHD with ongoing immunosuppression (HR, 9.49; 95% CI, 4.39 to 20.51) or without ongoing immunosuppression (HR, 2.7; 95% CI, 1.05 to 7.43) at 2 years post-HCT compared with no history of GVHD, diagnosis of inherited abnormalities of erythrocyte function compared with diagnosis of acute myelogenous leukemia (HR, 2.30; 95% CI, 1.19 to 4.42), and age >10 years (HR, 1.92; 95% CI, 1.15 to 3.2). This study emphasizes the importance of continued vigilance for late infections after HCT and institution of support strategies aimed at decreasing the risk of cGVHD.

Ethical considerations of using a single minor donor for three bone marrow harvests for three HLA-matched siblings with primary immunodeficiency.

Allogeneic hematopoietic stem cell transplantation is curative for primary immunodeficiencies. Bone marrow from an unaffected human leukocyte antigen (HLA)-identical sibling donor is the ideal graft source. For minor donors, meaningful consent or assent may not be feasible, and permission from parents or legal guardians is considered acceptable. Adverse events, albeit extremely small, can be associated with bone marrow harvest in pediatric donors. Donor safety concerns potentially increase with multiple bone marrow harvests. Very little is known about multiple bone marrow harvests from pediatric donors. We describe the ethical considerations and clinical decision-making in an unusual clinical situation where three patients with the same primary immunodeficiency were HLA identical to one another and their younger sibling, who underwent bone marrow harvests three times between 1.3 and 4 years of age, resulting in successful transplantation for all three patients. We hope that this experience will provide guidance to providers and families in a similar situation.

Survival outcomes of allogeneic hematopoietic cell transplants with EBV-positive or EBV-negative post-transplant lymphoproliferative disorder, A CIBMTR study.

BACKGROUND: Post-transplant lymphoproliferative disorders (PTLD) are associated with significant morbidity and mortality following allogeneic hematopoietic cell transplant (alloHCT). Although most PTLD is EBV-positive (EBVpos ), EBV-negative (EBVneg ) PTLD is reported, yet its incidence and clinical impact remain largely undefined. Furthermore, factors at the time of transplant impacting survival following PTLD are not well described. METHODS: Between 2002 and 2014, 432 cases of PTLD following alloHCT were reported to the Center for International Blood and Marrow Transplant Research (CIBMTR). After exclusions, 267 cases (EBVpos  = 222, 83%; EBVneg  = 45, 17%) were analyzed. RESULTS: Two hundred and eight patients (78%) received in vivo T-cell depletion (TCD) with either anti-thymocyte globulin (ATG) or alemtuzumab. Incidence of PTLD was highest using umbilical cord donors (UCB, 1.60%) and lowest using matched related donors (MRD, 0.40%). Clinical features and histology did not significantly differ among EBVpos or EBVneg PTLD cases except that absolute lymphocyte count recovery was slower, and CMV reactivation was later in EBVneg PTLD [EBVpos 32 (5-95) days versus EBVneg 47 (10-70) days, P = .016]. There was no impact on survival by EBV status in multivariable analysis [EBVneg RR 1.42, 95% CI 0.94-2.15, P = .097]. CONCLUSIONS: There is no difference in survival outcomes for patients with EBVpos or EBVneg PTLD occurring following alloHCT and 1-year survival is poor. Features of conditioning and use of serotherapy remain important.

Long-Term Functional Outcomes after Hematopoietic Stem Cell Transplant for Early Infantile Krabbe Disease.

Allogeneic hematopoietic stem cell transplantation (HSCT) can retard the progression of early infantile Krabbe disease (EIKD). Superior outcomes are achieved if HSCT is performed before the onset of symptoms; however, little information is available about the long-term outcomes in surviving patients. We now describe functional outcomes in presymptomatic infants who underwent HSCT for EIKD at ≤ 2 months of age. Records of the 19 patients who underwent HSCT for EIKD at ≤ 2 months of age from 1996 to 2010 were reviewed. Long-term functional outcomes were compared between those transplanted at < 30 days and ≥ 30 days of life. Median age at transplant was 27 days (range, 19 to 61). Median follow-up of the cohort was 12.6 years. Overall survival at 5 and 10 years post-transplant was 84.2% (95% confidence interval, 58.7% to 94.6%) and 78.6% (95% confidence interval, 52.5% to 91.4%), respectively. More favorable outcomes were seen in patients who underwent HSCT at < 30 days of age, particularly in domains of mobility (P = .01), communication (P = .02), and feeding (P = .008). Improved functional outcomes were observed when HSCT was performed in the first month of life, defining a critical period for intervention. These results support the implementation of newborn screening to enable rapid diagnosis and early treatment of infants with EIKD.

Development and validation of a rapid, aldehyde dehydrogenase bright-based cord blood potency assay.

Banked, unrelated umbilical cord blood provides access to hematopoietic stem cell transplantation for patients lacking matched bone marrow donors, yet 10% to 15% of patients experience graft failure or delayed engraftment. This may be due, at least in part, to inadequate potency of the selected cord blood unit (CBU). CBU potency is typically assessed before cryopreservation, neglecting changes in potency occurring during freezing and thawing. Colony-forming units (CFUs) have been previously shown to predict CBU potency, defined as the ability to engraft in patients by day 42 posttransplant. However, the CFU assay is difficult to standardize and requires 2 weeks to perform. Consequently, we developed a rapid multiparameter flow cytometric CBU potency assay that enumerates cells expressing high levels of the enzyme aldehyde dehydrogenase (ALDH bright [ALDH(br)]), along with viable CD45(+) or CD34(+) cell content. These measurements are made on a segment that was attached to a cryopreserved CBU. We validated the assay with prespecified criteria testing accuracy, specificity, repeatability, intermediate precision, and linearity. We then prospectively examined the correlations among ALDH(br), CD34(+), and CFU content of 3908 segments over a 5-year period. ALDH(br) (r = 0.78; 95% confidence interval [CI], 0.76-0.79), but not CD34(+) (r = 0.25; 95% CI, 0.22-0.28), was strongly correlated with CFU content as well as ALDH(br) content of the CBU. These results suggest that the ALDH(br) segment assay (based on unit characteristics measured before release) is a reliable assessment of potency that allows rapid selection and release of CBUs from the cord blood bank to the transplant center for transplantation.

Automated thawing increases recovery of colony-forming units from banked cord blood unit grafts.

BACKGROUND: The cell dose infused for cord blood transplantation strongly correlates with outcomes following transplantation. Post thaw recoveries can be improved by washing cord blood units (CBUs) in dextran/albumin. Early methods used a labor-intensive manual process. We have recently developed and validated an automated washing method. We now report our results of a study comparing cellular recoveries achieved after manual and automated wash, as well as the impact on engraftment following allogeneic transplantation. STUDY DESIGN AND METHODS: CBUs distributed by the Carolinas Cord Blood Bank for clinical use at Duke University after manual or automated wash were included in this report. Precryopreservation total nucleated cell count, total CD34+, colony-forming units, recoveries, and sterility were analyzed by wash method. Patient age, cell dose/weight, diagnosis, conditioning regimen, immunosuppression, and time to neutrophil engraftment were also analyzed. RESULTS: Manual and automated washed CBUs yielded similar total nucleated cell count and total CD34+ recoveries. Significantly higher colony-forming units recoveries were achieved after automated washing. Patients who received CBUs washed via an automated method experienced earlier neutrophil engraftment. CONCLUSION: While manual and automated washing achieved similar post thaw cellular recoveries, automated washed CBUs demonstrated higher colony-forming unit recovery, which is an important predictor of potency and engraftment. Furthermore, we demonstrated that automated washing was associated with earlier neutrophil engraftment. Our findings favor the use of an automated wash method over a manual approach.

Durable Chimerism and Long-Term Survival after Unrelated Umbilical Cord Blood Transplantation for Pediatric Hemophagocytic Lymphohistiocytosis: A Single-Center Experience.

Hemophagocytic lymphohistiocytosis (HLH) is a life-threatening disorder of immune dysregulation characterized by fever, hepatosplenomegaly, cytopenias, central nervous system disease, increased inflammatory markers, and hemophagocytosis. Currently, allogeneic hematopoietic stem cell transplantation is the only curative approach for patients with HLH, with reported survival ranging from 50% to 70% with myeloablative conditioning (MAC) regimens. However, donor availability and transplantation-related mortality associated with conventional MAC are major barriers to success. Unrelated umbilical cord blood transplantation (UCBT) provides a readily available alternative donor source for patients lacking matched related donors. Accordingly, we report the results of UCBT in 14 children treated between 1998 and 2016. All children received standard HLH chemotherapy before UCBT. The median age at diagnosis was 2.7 months (range, .8 to 10.4) and at transplantation was 7.5 months (range, 3.8 to 17). Ten patients received MAC with busulfan/cyclophosphamide/etoposide /antithymocyte globulin (ATG) (n = 5), busulfan/cyclophosphamide /ATG (n = 4), or busulfan /melphalan/ATG (n = 1). Four patients received reduced-toxicity conditioning (RTC) with alemtuzumab/fludarabine/melphalan/hydroxyurea ± thiotepa. Cord blood units were mismatched at either 1 (n = 9) or 2 (n = 5) loci and delivered a median total nucleated cell dose of 11.9 × 107/kg (range, 4.6 to 27.9) and CD34+ dose of 3.1 × 105/kg (range, 1.1 to 6.8). The cumulative incidence of neutrophil engraftment by day 42 was 78.6% (95% confidence interval [CI], 42.9% to 93.4%) with a median of 19 days (range, 13 to 27), and that for platelet (50,000) engraftment by day 100 was 64.3% (95% CI, 28.2% to 85.7%) with a median of 51 days (range, 31 to 94). Six patients developed either grade II (n = 5) or grade IV (n = 1) acute graft-versus-host disease (GVHD); no extensive chronic GVHD was seen. Ten patients (71.4%) are alive and well at a median of 11.2 years after transplantation (range, .85 to 18.25), 9 of whom maintain sustained full donor chimerism after a single UCBT, whereas 1 patient with autologous recovery after first UCBT with RTC has achieved full donor chimerism after a second UCBT with MAC. This series demonstrates that, in combination with standard HLH therapy, UCBT after MAC or RTC conditioning can provide long-term survival with durable complete donor chimerism comparable to that of conventional donors. UCBT should be considered for patients with HLH lacking a fully matched related or unrelated adult donor.

Haploidentical Bone Marrow Transplantation with Post-Transplant Cyclophosphamide for Children and Adolescents with Fanconi Anemia.

We describe haploidentical bone marrow transplantation with post-transplant cyclophosphamide (PT-CY) for 30 patients with Fanconi anemia (FA). Twenty-six patients were transplanted upfront, and the preparatory regimens included fludarabine 150 mg/m2 + total body irradiation 200 to 300 cGy ± CY 10 mg/kg without (n = 12) or with rabbit antithymocyte globulin (r-ATG) 4 to 5 mg/kg (n = 14). Four patients were rescued after primary or secondary graft failure after related or unrelated donor transplantation with the above regimen with (n = 2) or without r-ATG (n = 2). PT-CY at 25 mg/kg/day (total dose, 50 mg/kg) followed by cyclosporine and mycophenolate mofetil was given to all patients. All patients engrafted in the subgroup of patients who did not receive r-ATG (n = 14), but their transplant course was complicated by high rates of acute and chronic graft-versus-host disease (GVHD), and only 8 patients are alive. In the subgroup that received r-ATG (n = 16), 14 patients had sustained engraftment, severe GVHD rates were lower, and 13 patients are alive. Hemorrhagic cystitis occurred in 50% of patients, whereas cytomegalovirus reactivation occurred in 75%. One-year overall survival for the entire cohort was 73% (95% CI, 64% to 81%), and all surviving patients achieved full donor chimerism. In conclusion, haploidentical donor transplantation with PT-CY is a suitable option for FA patients without a matched related or unrelated donor.

Factors Associated with Long-Term Risk of Relapse after Unrelated Cord Blood Transplantation in Children with Acute Lymphoblastic Leukemia in Remission.

For pediatric patients with acute lymphoblastic leukemia (ALL), relapse is an important cause of treatment failure after unrelated cord blood transplant (UCBT). Compared with other donor sources, relapse is similar or even reduced after UCBT despite less graft-versus-host disease (GVHD). We performed a retrospective analysis to identify risk factors associated with the 5-year cumulative incidence of relapse after UCBT. In this retrospective, registry-based study, we examined the outcomes of 640 children (<18 years) with ALL in first complete remission (CR1; n = 257, 40%) or second complete remission (CR2; n = 383, 60%) who received myeloablative conditioning followed by a single-unit UCBT from 2000 to 2012. Most received antithymocyte globulin (88%) or total body irradiation (TBI; 69%), and cord blood grafts were primarily mismatched at 1 (50%) or 2+ (34%) HLA loci. Considering patients in CR1, the rates of 5-year overall survival (OS), leukemia-free survival (LFS), and relapse were 59%, 52%, and 23%, respectively. In multivariate analysis (MVA), acute GVHD (grades II to IV) and TBI protected against relapse. In patients in CR2, rates of 5-year OS, LFS, and the cumulative incidence of relapse were 46%, 44%, and 28%, respectively. In MVA, longer duration from diagnosis to UCBT (≥30 months) and TBI were associated with decreased relapse risk. Importantly, receiving a fully HLA matched graft was a strong risk factor for increased relapse in MVA. An exploratory analysis of all 640 patients supported the important association between the presence of acute GVHD and less relapse but also demonstrated an increased risk of nonrelapse mortality. In conclusion, the impact of GVHD as a graft-versus-leukemia marker is evident in pediatric ALL after UCBT. Strategies that promote graft-versus-leukemia while harnessing GVHD should be further investigated.

Personalized Prognostic Risk Score for Long-Term Survival for Children with Acute Leukemia after Allogeneic Transplantation.

We studied leukemia-free (LFS) and overall survival (OS) in children with acute myeloid (AML, n = 790) and acute lymphoblastic leukemia (ALL, n = 1096) who underwent transplantation between 2000 and 2010 and who survived for at least 1 year in remission after related or unrelated donor transplantation. Analysis of patient-, disease-, and transplantation characteristics and acute and chronic graft-versus-host disease (GVHD) was performed to identify factors with adverse effects on LFS and OS. These data were used to develop risk scores for survival. We did not identify any prognostic factors beyond 4 years after transplantation for AML and beyond 3 years for ALL. Risk score for survival for AML includes age, disease status at transplantation, cytogenetic risk group, and chronic GVHD. For ALL, the risk score includes age at transplantation and chronic GVHD. The 10-year probabilities of OS for AML with good (score 0, 1, or 2), intermediate (score 3), and poor risk (score 4, 5, 6, or 7) were 94%, 87%, and 68%, respectively. The 10-year probabilities of OS for ALL were 89% and 80% for good (score 0 or 1) and poor risk (score 2), respectively. Identifying children at risk for late mortality with early intervention may mitigate some excess late mortality.