A diagnostic classifier for pediatric chronic graft-versus-host disease: results of the ABLE/PBMTC 1202 study

The National Institutes of Health Consensus criteria for chronic graft-versus-host disease (cGVHD) diagnosis can be challenging to apply in children, making pediatric cGVHD diagnosis difficult. We aimed to identify diagnostic pediatric cGVHD biomarkers that would complement the current clinical criteria and help differentiate cGVHD from non-cGVHD. The Applied Biomarkers of Late Effects of Childhood Cancer (ABLE) study, open at 27 transplant centers, prospectively evaluated 302 pediatric patients after hematopoietic cell transplant (234 evaluable). Forty-four patients developed cGVHD. Mixed and fixed effect regression analyses were performed on diagnostic cGVHD onset blood samples for cellular and plasma biomarkers, with individual markers declared relevant if they met 3 criteria: an effect ratio ≥1.3 or ≤0.75; an area under the curve (AUC) of ≥0.60; and a P value <5.814 × 10-4 (Bonferroni correction) (mixed effect) or <.05 (fixed effect). To address the complexity of cGVHD diagnosis in children, we built a machine learning-based classifier that combined multiple cellular and plasma biomarkers with clinical factors. Decreases in regulatory natural killer cells, naïve CD4 T helper cells, and naïve regulatory T cells, and elevated levels of CXCL9, CXCL10, CXCL11, ST2, ICAM-1, and soluble CD13 (sCD13) characterize the onset of cGVHD. Evaluation of the time dependence revealed that sCD13, ST2, and ICAM-1 levels varied with the timing of cGVHD onset. The cGVHD diagnostic classifier achieved an AUC of 0.89, with a positive predictive value of 82% and a negative predictive value of 80% for diagnosing cGVHD. Our polyomic approach to building a diagnostic classifier could help improve the diagnosis of cGVHD in children but requires validation in future prospective studies. This trial was registered at www.clinicaltrials.gov as #NCT02067832.

Chronic gvhd dictionary-eurograft cost action initiative consensus report

Chronic graft versus host disease (cGVHD) affects patients after allogeneic hematopoietic stem cell transplantation (alloHSCT). This orphan disease poses a challenge for clinicians and researchers. The purpose of the cGVHD Dictionary is to provide a standardized structure for cGVHD databases on an international level, reconciling differences in data retrieval and facilitate database merging. It is derived from several consensus meetings of the EUROGRAFT consortium (European Cooperation in Science and Technology-COST Action CA17138) followed by a consensus process involving European Society for Blood and Marrow Transplantation (EBMT), US GvHD consortium and Center for International Bone Marrow Transplant Registry (CIBMTR). Databases used for the dictionary were: the National Institutes of Health (NIH) database, the Center for International Blood and Marrow Transplant Research, Applying Biomarkers to Minimize Long Term Effects of Childhood/Adolescent Cancer Treatment - Pediatric Blood and Marrow Transplant Consortium database, EBMT registry, the German-Austrian-Swiss GvHD registry, Italian Blood and Marrow Transplantation Society registry and Regensburg-Göttingen-Newcastle HSCT dataset. A four-part cGVHD Dictionary was formed based on the databases, consensus, and evidence in the literature. The Dictionary is divided into: (1) Patient characteristics, (2) Transplant characteristics, (3) cGVHD characteristics and (4) patient-reported quality of life, symptom burden and functional indicators.

A Prospective, Multicenter Study of Closed System Extracorporeal Photopheresis for Children With Steroid-Refractory Acute Graft-Versus-Host Disease

BACKGROUND

Steroid-refractory (SR) acute graft-versus-host disease (aGvHD) therapy involves intensive immunosuppression, which is associated with significant infectious risk. Extracorporeal photopheresis (ECP) is used to treat SR-aGvHD and is considered to be more immunomodulatory than immunosuppressive. However, pediatric data are mostly retrospective and often involve multi-step ECP that includes apheresis followed by separate photosensitizing/reinfusion on another device.

OBJECTIVE

To prospectively evaluate the efficacy and safety of a single-device ECP system in children with SR-aGvHD.

STUDY DESIGN

Open-label, multicenter, phase 3 study of the THERAKOS® CELLEX® Photopheresis System in children/young adults aged 1 to 21 years with SR-aGvHD. Patients were treated 3 times per week for 4 weeks, then twice weekly through week 12 while maintaining standard aGvHD prophylaxis. The primary efficacy endpoint was the proportion of patients achieving overall response (OR) at day 28 without the addition of next-line systemic treatment. Secondary endpoints included the proportion of patients achieving OR at weeks 8 and 12; the mean weekly steroid dose at weeks 4, 8, and 12; and treatment-emergent adverse events (TEAEs).

RESULTS

Twenty-nine children (median age, 8 years) were enrolled. OR was 55% by day 28, 74% by week 8, and 79% by week 12. Progressive improvements were observed in the skin and the gastrointestinal tract. Mean steroid dose decreased from 1.54 mg/kg/day at baseline to 0.90 mg/kg/day at week 4; 35% of patients achieved >50% steroid dose reduction at week 4 and 75% achieved >50% steroid dose reduction at week 12. Of 168 TEAEs reported among 25 patients (86%), 28 (17%) events were infections and 14 (8%) events were considered to be probably treatment related (all nonserious). Of 627 ECP treatments administered in children/young adults, 68% required blood priming. Treatment-related AEs, including hypotension, hypocalcemia, central line infection, and catheter-site bruising, were rare (1 event each). Three deaths occurred and were deemed unrelated to ECP by the investigators.

CONCLUSION

Use of the THERAKOS® CELLEX® Photopheresis System was effective in children with SR-aGvHD, with more than half experiencing improvement by day 28 and further responses observed over 12 weeks. Very few TEAEs were attributable to ECP, and no new safety signals were observed.

SARS-CoV-2 Infection and Active, Multiorgan, Severe cGVHD After HSCT for Adolescent ALL: More Luck Than Understanding? A Case Report

Graft-vs. -host disease (GvHD) is a serious and complex immunological complication of haematopoietic stem cell transplantation (HSCT) and is associated with prolonged immunodeficiency and non-relapse mortality. Standard treatment of chronic GvHD comprises steroids in combination with other immunosuppressive agents. Extracorporeal photopheresis (ECP), with its immunomodulatory mechanism, is applied as part of steroid-sparing regimens for chronic GvHD. Immunocompromised, chronically ill patients are at particular risk of severe disease courses of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. T-cell immunity in SARS-CoV-2 infection is well-described but the role of the humoral immune responses is not fully understood. This case report describes a moderate course of SARS-CoV-2 infection in a patient <9 months after HSCT who was suffering from active, severe, chronic GvHD treated with prednisone and ECP. Following HSCT from a matched unrelated donor to cure acute lymphoblastic leukaemia, the 25-year-old male patient experienced multiple infectious complications associated with cytopenia, B-cell dyshomeostasis and autoantibody production followed by development of severe chronic GvHD thereafter at day +212. The steroid-sparing treatment plan consisted of supportive care, topical treatment, prednisone and ECP. He was diagnosed with SARS-CoV-2 infection at day +252, experiencing loss of smell and taste as well as a cough. The patient's oxygen saturation was between 94 and 97% on room air, and computed tomography images showed evolution of typical of SARS-CoV-2 infiltrates. In addition to cytopenia and immune dyshomeostasis, laboratory tests confirmed macrophage activating syndrome, transaminitis and Epstein-Barr virus viraemia. At that time, anti-SARS-CoV-2 monoclonal antibodies were not available in Austria and remdesivir seemed contraindicated. Surprisingly, despite severe lymphopenia the patient developed SARS-CoV-2-specific antibodies within 15 days, which was followed by clearance of SARS-CoV-2 and EBV with resolution of symptoms. Thereafter, parameters of immune dysregulation such as lymphopenia and B-cell dyshomeostasis, the latter characterised by elevated CD21low B cells and autoantibody expression, normalised. Moreover, we observed complete response of active chronic GvHD to treatment.

Corrigendum: To Lighten the Burden of Cure: Thyroid Disease in Long-Term Survivors After TBI Conditioning for Paediatric ALL

[This corrects the article DOI: 10.3389/fped.2021.798974.].

Management of Chronic Graft-vs.-Host Disease in Children and Adolescents With ALL: Present Status and Model for a Personalised Management Plan

Herein we review current practice regarding the management of chronic graft-vs.-host disease (cGvHD) in paediatric patients after allogeneic haematopoietic stem cell transplantation (HSCT) for acute lymphoblastic leukaemia (ALL). Topics covered include: (i) the epidemiology of cGvHD; (ii) an overview of advances in our understanding cGvHD pathogenesis; (iii) current knowledge regarding risk factors for cGvHD and prevention strategies complemented by biomarkers; (iii) the paediatric aspects of the 2014 National Institutes for Health-defined diagnosis and grading of cGvHD; and (iv) current options for cGvHD treatment. We cover topical therapy and newly approved tyrosine kinase inhibitors, emphasising the use of immunomodulatory approaches in the context of the delicate counterbalance between immunosuppression and immune reconstitution as well as risks of relapse and infectious complications. We examine real-world approaches of response assessment and tapering schedules of treatment. Furthermore, we report on the optimal timepoints for therapeutic interventions and changes in relation to immune reconstitution and risk of relapse/infection. Additionally, we review the different options for anti-infectious prophylaxis. Finally, we put forth a theory of a holistic view of paediatric cGvHD and its associated manifestations and propose a checklist for individualised risk evaluation with aggregated considerations including site-specific cGvHD evaluation with attention to each individual's GvHD history, previous medical history, comorbidities, and personal tolerance and psychosocial circumstances. To complement this checklist, we present a treatment algorithm using representative patients to inform the personalised management plans for patients with cGvHD after HSCT for ALL who are at high risk of relapse.

Characteristics, management, and outcome of pediatric patients with post-transplant lymphoproliferative disease-A 20 years' experience from Austria

BACKGROUND

Management of pediatric post-transplantation lymphoproliferative disorder (PTLD) after hematopoietic stem cell (HSCT) and solid organ transplantation (SOT) is challenging.

AIM

This study of 34 PTLD patients up to 19-years old diagnosed in Austria from 2000 to 2018 aimed at assessing initial characteristics, therapy, response, and outcome as well as prognostic markers of this rare pediatric disease.

METHODS AND RESULTS

A retrospective data analysis was performed. Types of allografts were kidney (n = 12), liver (n = 7), heart (n = 5), hematopoietic stem cells (n = 4), lungs (n = 2), multi-visceral (n = 2), small intestine (n = 1), and vessels (n = 1). Eighteen/34 were classified as monomorphic PTLD, with DLBCL accounting for 15 cases. Polymorphic disease occurred in nine, and non-destructive lesions in six cases. One patient had a non-classifiable PTLD. Thirteen/34 patients are surviving event-free in first remission (non-destructive, n = 4/6; polymorphic, n = 4/9; monomorphic, n = 6/18). Fourteen/34 patients lacked complete response to first-line therapy, of whom seven died. Four/34 patients relapsed, of whom two died. In 3/34 patients, death occurred as a first event. The 5-year overall and event-free survival rates were 64% ± 9% and 35% ± 9% for the whole cohort. Among all parameters analyzed, only malignant disease as the indication for transplantation had a significantly poor influence on survival.

CONCLUSIONS

This study shows PTLD still to be a major cause of mortality following SOT or HSCT in children. A continued understanding of the molecular biology of the disease shall allow to decrease treatment intensity for lower risk patients and to identify patients who may benefit from newer therapy approaches to improve outcome and decrease morbidity.

Presence of viremia during febrile neutropenic episodes in patients undergoing chemotherapy for malignant neoplasms

The importance of viral infections as a leading cause of morbidity and mortality is well documented in severely immunosuppressed patients undergoing allogeneic stem cell transplantation. By contrast, viral infections generally receive less attention in patients with malignant disorders undergoing chemotherapy, where the onset of neutropenic fever is mostly associated with bacterial or fungal infections, and screening for viral infections is not routinely performed. To address the occurrence of invasive viral infections in a clinical setting commonly associated with less pronounced immunosuppression, we have prospectively screened 237 febrile neutropenic episodes in pediatric (n = 77) and adult (n = 69) patients undergoing intensive chemotherapy, primarily for treatment of acute leukemia. Serial peripheral blood specimens were tested by RQ-PCR assays for the presence and quantity of the clinically relevant viruses CMV, EBV, HHV6 and HAdV, commonly reactivated in highly immunocompromised patients. Viremia was documented in 36 (15%) episodes investigated, including the detection of HHV6 (n = 14), EBV (n = 15), CMV (n = 6), or HAdV (n = 1). While low or intermediate levels of viremia (<10⁴ virus copies/mL) were commonly associated with bacterial or fungal co-infection, viremia at higher levels (>10⁴ copies/mL) was documented in patients without evidence for other infections, raising the possibility that at least in some instances the onset of fever may have been attributable to the virus detected. The observations suggest that viral infections, potentially resulting from reactivation, might also play a clinically relevant role in patients receiving chemotherapy for treatment of malignant neoplasms, and routine screening for viremia in this clinical setting might be warranted.

Case Report: A Novel IL2RG Frame-Restoring Rescue Mutation Mimics Early T Cell Engraftment Following Haploidentical Hematopoietic Stem Cell Transplantation in a Patient With X-SCID

Mutations of the interleukin 2 receptor γ chain (IL2RG) result in the most common form of severe combined immunodeficiency (SCID), which is characterized by severe and persistent infections starting in early life with an absence of T cells and natural killer cells, normal or elevated B cell counts and hypogammaglobulinemia. SCID is commonly fatal within the first year of life, unless the immune system is reconstituted by hematopoietic stem cell transplantation (HSCT) or gene therapy. We herein describe a male infant with X-linked severe combined immunodeficiency (X-SCID) diagnosed at 5 months of age. Genetic testing revealed a novel C to G missense mutation in exon 1 resulting in a 3' splice site disruption with premature stop codon and aberrant IL2 receptor signaling. Following the diagnosis of X-SCID, the patient subsequently underwent a TCRαβ/CD19-depleted haploidentical HSCT. Post transplantation the patient presented with early CD8⁺ T cell recovery with the majority of T cells (>99%) being non-donor T cells. Genetic analysis of CD4⁺ and CD8⁺ T cells revealed a spontaneous 14 nucleotide insertion at the mutation site resulting in a novel splice site and restoring the reading frame although defective IL2RG function was still demonstrated. In conclusion, our findings describe a spontaneous second-site mutation in IL2RG as a novel cause of somatic mosaicism and early T cell recovery following haploidentical HSCT.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: IIa. The 2020 Clinical Implementation and Early Diagnosis Working Group Report

Recognition of the earliest signs and symptoms of chronic graft-versus-host disease (GVHD) that lead to severe manifestations remains a challenge. The standardization provided by the National Institutes of Health (NIH) 2005 and 2014 consensus projects has helped improve diagnostic accuracy and severity scoring for clinical trials, but utilization of these tools in routine clinical practice is variable. Additionally, when patients meet the NIH diagnostic criteria, many already have significant morbidity and possibly irreversible organ damage. The goals of this early diagnosis project are 2-fold. First, we provide consensus recommendations regarding implementation of the current NIH diagnostic guidelines into routine transplant care, outside of clinical trials, aiming to enhance early clinical recognition of chronic GVHD. Second, we propose directions for future research efforts to enable discovery of new, early laboratory as well as clinical indicators of chronic GVHD, both globally and for highly morbid organ-specific manifestations. Identification of early features of chronic GVHD that have high positive predictive value for progression to more severe manifestations of the disease could potentially allow for future pre-emptive clinical trials.

National Institutes of Health Consensus Development Project on Criteria for Clinical Trials in Chronic Graft-versus-Host Disease: IIb. The 2020 Preemptive Therapy Working Group Report

Chronic graft-versus-host disease (GVHD) commonly occurs after allogeneic hematopoietic cell transplantation (HCT) despite standard prophylactic immune suppression. Intensified universal prophylaxis approaches are effective but risk possible overtreatment and may interfere with the graft-versus-malignancy immune response. Here we summarize conceptual and practical considerations regarding preemptive therapy of chronic GVHD, namely interventions applied after HCT based on evidence that the risk of developing chronic GVHD is higher than previously appreciated. This risk may be anticipated by clinical factors or risk assignment biomarkers or may be indicated by early signs and symptoms of chronic GVHD that do not fully meet National Institutes of Health diagnostic criteria. However, truly preemptive, individualized, and targeted chronic GVHD therapies currently do not exist. In this report, we (1) review current knowledge regarding clinical risk factors for chronic GVHD, (2) review what is known about chronic GVHD risk assignment biomarkers, (3) examine how chronic GVHD pathogenesis intersects with available targeted therapeutic agents, and (4) summarize considerations for preemptive therapy for chronic GVHD, emphasizing trial development, including trial design and statistical considerations. We conclude that robust risk assignment models that accurately predict chronic GVHD after HCT and early-phase preemptive therapy trials represent the most urgent priorities for advancing this novel area of research.

Current practice in nutrition after allogeneic hematopoietic stem cell transplantation - Results from a survey among hematopoietic stem cell transplant centers

BACKGROUND

Allogeneic hematopoietic stem cell transplantation (alloHSCT) is frequently associated with impaired oral intake and malnutrition, which potentially increases morbidity and mortality. Therefore, nutrition is one of the major challenges in the post-transplant period.

METHODS

To document the current clinical approach in nutritional treatment, we designed a questionnaire concerning the current practice in nutrition after alloHSCT and distributed it to German speaking centers performing alloHSCT in Germany, Austria and Switzerland between November 2018 and March 2020. Twenty-eight (39%) of 72 contacted centers completed the survey, 23 from Germany, two from Austria and three from Switzerland, representing 50% of alloHSCT activity within the participating countries in 2018.

RESULTS

All centers reported having nutritional guidelines for patients undergoing alloHSCT, whereby 86% (n = 24) provided a low-microbial diet during the neutropenic phase. The criteria to start parenteral nutrition (PN) directly after alloHSCT seemed to be consistent, 75% (n = 21) of the corresponding centers started PN if the oral nutritional intake or the bodyweight dropped below a certain limit. In the setting of intestinal graft-versus-host disease (GvHD) the current practice appeared to be more heterogenous. About 64% (n = 18) of the centers followed a special diet, added food stepwise modulated by GvHD symptoms, while only four centers regularly stopped oral intake completely (intestinal GvHD grade >1). Half of the centers (54%, n = 15) applied a lactose-free diet, followed by 43% (n = 12) which provided fat- and 18% (n = 5) gluten-free food in patients with intestinal GvHD. Supplementation of micronutrients in acute intestinal GvHD patients was performed by 54% (n = 15) of the centers, whereas vitamin D (89%, n = 25) and vitamin B₁₂ (68%, n = 19) was added regularly independently of the presence of GvHD. Only 5 (18%) participating centers ever observed a food-associated infection during hospitalization, whereas food-associated infections were reported to occur more often in the outpatient setting (64%, n = 18).

CONCLUSION

The survey documented a general consensus about the need for nutritional guidelines for patients undergoing alloHSCT. However, the nutritional treatment in clinical practice (i.e. lactose-, gluten- or fat-free in intestinal GvHD) as well as the use of food supplements was very heterogeneous. In line with current general recommendations the centers seemed to focus on safe food handling practice rather than providing a strict neutropenic diet. More high-quality data are required to provide evidence-based nutrition to patients during and after alloHSCT.

Supportive Care During Pediatric Hematopoietic Stem Cell Transplantation: Prevention of Infections. A Report From Workshops on Supportive Care of the Paediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT)

Specific protocols define eligibility, conditioning, donor selection, graft composition and prophylaxis of graft vs. host disease for children and young adults undergoing hematopoietic stem cell transplant (HSCT). However, international protocols rarely, if ever, detail supportive care, including pharmaceutical infection prophylaxis, physical protection with face masks and cohort isolation or food restrictions. Supportive care suffers from a lack of scientific evidence and implementation of practices in the transplant centers brings extensive restrictions to the child's and family's daily life after HSCT. Therefore, the Board of the Pediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT) held a series of dedicated workshops since 2017 with the aim of initiating the production of a set of minimal recommendations. The present paper describes the consensus reached within the field of infection prophylaxis.

Current Prophylaxis and Treatment Approaches for Acute Graft-Versus-Host Disease in Haematopoietic Stem Cell Transplantation for Children With Acute Lymphoblastic Leukaemia

Acute graft-versus-host disease (aGvHD) continues to be a leading cause of morbidity and mortality following allogeneic haematopoietic stem cell transplantation (HSCT). However, higher event-free survival (EFS) was observed in patients with acute lymphoblastic leukaemia (ALL) and grade II aGvHD vs. patients with no or grade I GvHD in the randomised, controlled, open-label, international, multicentre Phase III For Omitting Radiation Under Majority age (FORUM) trial. This finding suggests that moderate-severity aGvHD is associated with a graft-versus-leukaemia effect which protects against leukaemia recurrence. In order to optimise the benefits of HSCT for leukaemia patients, reduction of non-relapse mortality-which is predominantly caused by severe GvHD-is of utmost importance. Herein, we review contemporary prophylaxis and treatment options for aGvHD in children with ALL and the key challenges of aGvHD management, focusing on maintaining the graft-versus-leukaemia effect without increasing the severity of GvHD.

Value of Autoantibody Expression During Long-Term Follow-Up in Paediatric ALL Patients After Allogeneic Haematopoietic Stem Cell Transplantation

Objectives: Chronic graft-versus-host disease (cGvHD) following haematopoietic stem cell transplantation (HSCT) shares many similarities with de novo autoimmune disorders, being associated with the presence of autoantibodies. However, data on the implication of autoantibodies in paediatric HSCT recipients are scarce. In this single-centre study of paediatric patients with acute lymphoblastic leukaemia (ALL) surviving longer than 3 months, our objectives were to evaluate autoantibody expression and investigate the correlation with cGvHD and immune reconstitution using serially monitored parameters. Methods: We investigated circulating autoantibodies together with cellular and humoral parameters [including major T- and B-cell subsets, natural killer (NK) cells, and immunoglobulin levels] in 440 samples from 74 patients (median age 10.9 years, range 2.7-22.2 years) serially during long-term follow-up of median 8 years (range 0.4-19.3 years). Evaluations comprised of patient and transplant characteristics, precisely reviewed details of National Institute of Health (NIH)-defined cGvHD, and outcome data such as relapse, overall survival (OS) and mortality. Analysis of these clinical parameters was performed to identify possible associations. Results: Autoantibodies were detected in 65% (48/74) of patients. Anti-nuclear antibodies were the most common, occurring in 75% (36/48) of patients with autoantibodies. When comparing demographic data and transplant characteristics, there were no significant differences between patients with and without autoantibody expression; 5-year OS was excellent, at 96.4 and 95.8%, respectively. Neither the expression of autoantibodies nor the occurrence of cGvHD correlated with significantly worse OS or relapse rate. Furthermore, there was no significant association between autoantibody profiles and the incidence, overall severity or organ involvement of cGvHD. Patients with autoantibodies showed significantly better immune reconstitution, with overall higher numbers of T cells, B cells, and serum immunoglobulins. In autoantibody-positive patients with cGvHD, autoantibody production positively correlated with the expansion of CD56+ NK cells (236.1 vs. 165.6 × 10³ cells/mL, respectively; p = 0.023) and with signs of B-cell perturbation, such as higher CD21^low B cells (23.8 vs. 11.8 × 10³ cells/mL, respectively; p = 0.044) and a higher ratio of CD21^low B cells/CD27⁺ memory B cells (1.7 vs. 0.4, respectively; p = 0.006) in comparison to autoantibody-positive patients without cGvHD. Furthermore, when assessing the correlation between autoantibody positivity and the activity of cGvHD at time of analysis, indicators of aberrant B-cell homeostasis were substantiated by a lower proportion of CD27⁺ memory B cells (9.1 vs. 14.9%, respectively; p = 0.028), a higher ratio of class-switched CD27⁺IgD^-/CD27⁺ memory B cells (3.5 vs. 5.1%, respectively; p = 0.013), significantly elevated numbers of CD21^low B cells (36.8 vs. 11.8 × 10³ cells/mL, respectively; p = 0.013) and a higher ratio of CD21^lowB cells/CD27⁺ memory B cells (2.4 vs. 0.4, respectively; p = 0.034) in the active vs. the no cGvHD group. We then assessed the potential role of autoantibody expression in the context of elevated CD19⁺CD21^low B cells (cutoff >7%), a well-known marker of cGvHD. Surprisingly we found a significant higher proportion of those cases where elevated CD21^low B cells correlated with active cGvHD in samples from the autoantibody-negative group vs. the antibody-positive group (82 vs. 47%, respectively; p = 0.0053). When comparing immune parameters of the large proportion of survivors (89%) with the small proportion of non-survivors (11%), data revealed normalisation within the B-cell compartment of survivors: there were increased numbers of CD27⁺ memory B cells (54.9 vs. 30.6 × 10³ cells/mL, respectively; p = 0.05), class-switched CD27⁺IgD^- B cells (21.2 vs. 5.0 × 10³ cells/mL, respectively; p < 0.0001), and immunoglobulin G4 (40.9 vs. 19.4 mg/dL, respectively; p < 0.0001). Overall mortality was significantly associated with an elevated proportion of CD21^low B cells (13.4 vs. 8.8%, respectively; p = 0.039) and CD56⁺ NK cells (238.8 vs. 314.1 × 10³ cells/mL, respectively; p = 0.019). In multivariate analysis, better OS was significantly associated with lower numbers of CD56⁺ NK cells [hazard ratio (HR) 0.98, p = 0.041] and higher numbers of CD27⁺ memory B cells [(HR) 1.62, p = 0.014]. Conclusion: Our data shows that autoantibody profiles are not suitable biomarkers for diagnosing cGvHD in children or for predicting cGvHD severity, disease course and outcome. We identified a number of indicators of aberrant immune homeostasis associated with active cGvHD in paediatric ALL patients after HSCT. These findings confirm published results and suggest that candidate B cell subpopulations may serve as a surrogate measure for characterisation of cGvHD in paediatric HSCT for malignant diseases, and warrants confirmation in larger, multicentre studies.

Immune Reconstitution After Allogeneic Haematopoietic Cell Transplantation: From Observational Studies to Targeted Interventions

Immune reconstitution (IR) after allogeneic haematopoietic cell transplantation (HCT) represents a central determinant of the clinical post-transplant course, since the majority of transplant-related outcome parameters such as graft-vs.-host disease (GvHD), infectious complications, and relapse are related to the velocity, quantity and quality of immune cell recovery. Younger age at transplant has been identified as the most important positive prognostic factor for favourable IR post-transplant and, indeed, accelerated immune cell recovery in children is most likely the pivotal contributing factor to lower incidences of GvHD and infectious complications in paediatric allogeneic HCT. Although our knowledge about the mechanisms of IR has significantly increased over the recent years, strategies to influence IR are just evolving. In this review, we will discuss different patterns of IR during various time points post-transplant and their impact on outcome. Besides IR patterns and cellular phenotypes, recovery of antigen-specific immune cells, for example virus-specific T cells, has recently gained increasing interest, as certain threshold levels of antigen-specific T cells seem to confer protection against severe viral disease courses. In contrast, the association between IR and a possible graft-vs. leukaemia effect is less well-understood. Finally, we will present current concepts of how to improve IR and how this could change transplant procedures in the near future.

A Review of Acute and Long-Term Neurological Complications Following Haematopoietic Stem Cell Transplant for Paediatric Acute Lymphoblastic Leukaemia

Despite advances in haematopoietic stem cell transplant (HSCT) techniques, the risk of serious side effects and complications still exists. Neurological complications, both acute and long term, are common following HSCT and contribute to significant morbidity and mortality. The aetiology of neurotoxicity includes infections and a wide variety of non-infectious causes such as drug toxicities, metabolic abnormalities, irradiation, vascular and immunologic events and the leukaemia itself. The majority of the literature on this subject is focussed on adults. The impact of the combination of neurotoxic drugs given before and during HSCT, radiotherapy and neurological complications on the developing and vulnerable paediatric and adolescent brain remains unclear. Moreover, the age-related sensitivity of the nervous system to toxic insults is still being investigated. In this article, we review current evidence regarding neurotoxicity following HSCT for acute lymphoblastic leukaemia in childhood. We focus on acute and long-term impacts. Understanding the aetiology and long-term sequelae of neurological complications in children is particularly important in the current era of immunotherapy for acute lymphoblastic leukaemia (such as chimeric antigen receptor T cells and bi-specific T-cell engager antibodies), which have well-known and common neurological side effects and may represent a future treatment modality for at least a fraction of HSCT-recipients.

To Lighten the Burden of Cure: Thyroid Disease in Long-Term Survivors After TBI Conditioning for Paediatric ALL

Thyroid disorders are well-studied after allogeneic haematopoietic stem cell transplantation (HSCT) following total body irradiation (TBI)-based conditioning, occurring in 15-30% of paediatric survivors. The toxic effect of TBI is known but data on the role of immunological dysregulation (ID) and chronic graft-versus-host-disease (cGvHD) are scarce. We studied functional and structural thyroid disorders in 97 paediatric ALL patients after TBI-based HSCT, assessing their correlation with patient/transplant characteristics including cGvHD, prolonged immunosuppression and ID. The 10- and 15-year cumulative incidence (CI) of functional disorders was 50 and 60%. Univariate analysis revealed TBI in 6 vs. 8 fractions (p = 0.01), an interval between ALL diagnosis and HSCT <1 year (p = 0.038), and the application of ATG (p = 0.044) as risk factors. The 10- and 15-year CI of structural disorders was 60 and 80%. No correlation between patient/transplant characteristics and structural disorders was observed. cGvHD, prolonged immunosuppression and additional radiotherapy were not associated with any thyroid disease. We observed a significant correlation between ID and the development of thyroid dysfunction in patients with structural changes (10-year CI: 77% for patients with ID vs. 56% without ID, p = 0.02). The impact of our results on thyroid follow-up evaluations and the significance of hormonal replacement therapy are discussed.

Evaluation of the Cost of Survivorship Care After Allogeneic Hematopoeitic Stem Cell Transplantation-An Analysis of 2 German Transplantation Centers

The aim of the presented study was to analyze the care expenditure for outpatients after allogeneic hematopoietic stem cell transplantation (alloHSCT) done in accordance with the national, European guidelines and the German Social Law. We performed an analysis of the National and European survivorship care guidelines and in parallel recorded the time expenditure and staff costs separated according to different occupational groups involved in outpatient care at two German transplantation centers [University Hospital Regensburg (UKR) and University Hospital Hamburg-Eppendorf (UKE)]. In addition, we performed a comparison of real costs vs. reimbursed costs according to the standard rating benchmark catalog (EBM), which was supplemented by a survey of German transplantation centers. The results showed that the staff costs are only covered by the EBM for patients without complications during long-term follow-up care-notably, this accounts for 15% of alloHSCT patients. Staff costs for patients requiring treatment of graft-vs.-host disease or relapse of the malignant underlying malignancy exceed to the factor 6.5 (UKR) to 12 (UKE) of the EBM revenue, caused both by the increased duration and frequency of the outpatient visits. As a result of the survey at German transplant centers, 15 out of 18 responding centers reported a lack of cost coverage for follow-up care. Two/15 centers reported that survivorship care is limited to a restricted time, independent of patient's needs, due to a lack of cost reimbursement. The results show that alloHSCT survivorship care of patients requires significant staff resources, which are not covered by the current version of the German EBM catalog. New approaches to finance labor intensive after care of transplant patients are required.

Investigation and Management of Bone Mineral Density Following Hematopoietic Cell Transplantation: A Survey of Current Practice by the Transplant Complications Working Party of the European Society for Blood and Marrow Transplantation

Reduced bone mineral density (BMD) is a well-recognized complication of hematopoietic cell transplantation (HCT), with significant drops in BMD occurring within the first 12 months after HCT. Guidance on identifying and managing this complication is available in several published guidelines. In this study, we investigated current practices in the investigation and management of low BMD in centers registered with the European Society for Blood and Marrow Transplantation (EBMT). A questionnaire about bone health was sent to all registered centers, and responses were received from 99 centers in 25 countries (52%) currently registered with the EBMT. Our data highlight considerable heterogeneity in practices across European centers in relation to investigations, management, and use of guidelines. Our data demonstrate the need for better dissemination and implementation of existing guidelines and also for the development of multidisciplinary guidelines with input from all relevant stakeholders.

A Web-Based Mobile App (INTERACCT App) for Adolescents Undergoing Cancer and Hematopoietic Stem Cell Transplantation Aftercare to Improve the Quality of Medical Information for Clinicians: Observational Study

Background

A growing number of cancer and hematopoietic stem cell transplant (HSCT) survivors require long-term follow-up with optimal communication schemes, and patients' compliance is crucial. Adolescents have various unmet needs. Regarding self-report of symptoms and health status, users of mobile apps showed enhanced compliance. Currently, HSCT aftercare at the HSCT outpatient clinic of the St. Anna Children’s Hospital in Vienna, Austria, is based on handwritten diaries, carrying various disadvantages. Recently, we developed the prototype of a web-based, self-monitoring gamified mobile app tailored for adolescents: the INTERACCT (Integrating Entertainment and Reaction Assessment into Child Cancer Therapy) app.

Objective

This observational, prospective study evaluated the usability of the INTERACCT app for tracking real-time self-reported symptoms and health status data in adolescent HSCT patients and a healthy matched control group. The primary outcome of the study was the quality of the self-reported medical information. We hypothesized that the mobile app would provide superior medical information for the clinicians than would the handwritten diaries.

Methods

Health data were reported via paper diary and mobile app for 5 consecutive days each. The quality of medical information was rated on a 5-point scale independently and blinded by two HSCT clinicians, and the duration of use was evaluated. A total of 52 participant questionnaires were assessed for gaming patterns and device preferences, self-efficacy, users’ satisfaction, acceptability, and suggestions for improvement of the mobile app. Interrater reliability was calculated with the intraclass correlation coefficient, based on a two-way mixed model; one-way repeated-measures analysis of variance and t tests were conducted post hoc. Descriptive methods were used for correlation with participants’ demographics. For users’ satisfaction and acceptability of the mobile app, the median and the IQR were calculated.

Results

Data from 42 participants—15 patients and 27 healthy students—with comparable demographics were evaluated. The results of our study indicated a superiority of the quality of self-reported medical data in the INTERACCT app over traditional paper-and-pencil assessment (mobile app: 4.14 points, vs paper-based diary: 3.77 points, P=.02). The mobile app outperformed paper-and-pencil assessments mainly among the patients, in particular among patients with treatment-associated complications (mobile app: 4.43 points, vs paper-based diary: 3.73 points, P=.01). The mobile app was used significantly longer by adolescents (≥14 years: 4.57 days, vs ≤13 years: 3.14 days, P=.03) and females (4.76 days for females vs 2.95 days for males, P=.004). This corresponds with a longer duration of use among impaired patients with comorbidities. User satisfaction and acceptability ratings for the mobile app were high across all groups, but adherence to entering a large amount of data decreased over time. Based on our results, we developed a case vignette of the target group.

Conclusions

Our study was the first to show that the quality of patient-reported medical information submitted via the INTERACCT app embedded in a serious game is superior to that submitted via a handwritten diary. In light of these results, a refinement of the mobile app supported by a machine learning approach is planned within an international research project.

Human papillomavirus in female adolescents and young adults after allogeneic hematopoietic stem cell transplantation-Not a problem prior to coitarche

OBJECTIVES

To evaluate the prevalence of HPV colonization in female adolescents and young adults after allogenic hematopoietic stem cell transplantation.

STUDY DESIGN

In this prospective pilot study, we enrolled 18 girls and young women aged 12-22 years cared for at the SCT (stem cell transplantation) Outpatient Clinic of the St. Anna children's hospital. Vaginal, buccal, and rectal HPV swabs were collected twice at intervals of 2-6 months at the Outpatient Clinic for children's and adolescents' gynecology of the University Clinic for Gynecology Vienna.

RESULTS

Overall, 3 (16.7%; 95% CL [≥0.0%; 33.9%]) of the 18 patients were vaginally HPV-positive at least at one timepoint. Among these three, two patients belonged to the smaller sub-group (3 patients) of patients after coitarche and one patient belonged to the larger one (15 patients) of patients prior to coitarche. In one of the three vaginally HPV-positive patients, we also found HPV DNA rectally. Orally, HPV DNA could not be detected at all.

CONCLUSIONS

According to the data of this study, vaginal, buccal, and rectal HPV colonization seems to be of little relevance in girls and young women after HSCT prior to coitarche. As expected, a higher risk for vaginal HPV colonization could be shown by trend for patients after coitarche, but also for those having been treated with total body irradiation as a conditioning regimen and for those showing signs of vaginal hypoestrogenization-which has not been published so far.

Immune profile differences between chronic GVHD and late acute GVHD: results of the ABLE/PBMTC 1202 studies

Human graft-versus-host disease (GVHD) biology beyond 3 months after hematopoietic stem cell transplantation (HSCT) is complex. The Applied Biomarker in Late Effects of Childhood Cancer study (ABLE/PBMTC1202, NCT02067832) evaluated the immune profiles in chronic GVHD (cGVHD) and late acute GVHD (L-aGVHD). Peripheral blood immune cell and plasma markers were analyzed at day 100 post-HSCT and correlated with GVHD diagnosed according to the National Institutes of Health consensus criteria (NIH-CC) for cGVHD. Of 302 children enrolled, 241 were evaluable as L-aGVHD, cGVHD, active L-aGVHD or cGVHD, and no cGVHD/L-aGVHD. Significant marker differences, adjusted for major clinical factors, were defined as meeting all 3 criteria: receiver-operating characteristic area under the curve ≥0.60, P ≤ .05, and effect ratio ≥1.3 or ≤0.75. Patients with only distinctive features but determined as cGVHD by the adjudication committee (non-NIH-CC) had immune profiles similar to NIH-CC. Both cGVHD and L-aGVHD had decreased transitional B cells and increased cytolytic natural killer (NK) cells. cGVHD had additional abnormalities, with increased activated T cells, naive helper T (Th) and cytotoxic T cells, loss of CD56bright regulatory NK cells, and increased ST2 and soluble CD13. Active L-aGVHD before day 114 had additional abnormalities in naive Th, naive regulatory T (Treg) cell populations, and cytokines, and active cGVHD had an increase in PD-1- and a decrease in PD-1+ memory Treg cells. Unsupervised analysis appeared to show a progression of immune abnormalities from no cGVHD/L-aGVHD to L-aGVHD, with the most complex pattern in cGVHD. Comprehensive immune profiling will allow us to better understand how to minimize L-aGVHD and cGVHD. Further confirmation in adult and pediatric cohorts is needed.

Nature's endless wonder: unexpected motherhood after pediatric allogeneic stem cell transplantation and severe late effects

Infertility and endocrine late effects (LE) are common sequelae after pediatric allogeneic hematopoietic stem cell transplantation (HSCT) after myeloablative conditioning. Nevertheless, the individual risk for these LE is not always easy to predict and therefore these issues are of ongoing interest to the clinical research community dealing with HSCT aftercare. This article describes the case of a young woman who received polychemotherapy and total body irradiation (TBI) containing conditioning for HSCT for a relapsed anaplastic large cell lymphoma (ALCL). She developed severe sclerotic chronic graft-versus-host disease (GVHD) with irreversible joint contractures and multiorgan involvement, requiring long-term multimodal immunosuppressive treatment. Subsequently showing a considerable number of LE including hypergonadotropic hypogonadism, she accepted that infertility would be quite likely. Her courageous personal life planning included part-time working and a partnership but not motherhood. This article reports the unexpected and spontaneous pregnancy and the extreme preterm birth of a surprisingly adequately developing child.

Pediatric acute graft-versus-host disease prophylaxis and treatment: surveyed real-life approach reveals dissimilarities compared to published recommendations

Pediatric allogeneic hematopoietic cell transplantation (HCT) practices differ from those of adults, particularly the heterogeneity of transplantable nonmalignant diseases and the lower incidence of graft‐versus‐host disease (GVHD). Several guidelines regarding the management of acute (a) GVHD in adult HCT have been published. We aimed to capture the real‐life approaches for pediatric aGVHD prophylaxis/treatment, and data from 75/193 (response rate 39%) EBMT centers (26 countries) were included, representing half (48%) of the pediatric EBMT‐HCT activity. Results with ≥75% approval from respondents (74/75) for GVHD prophylaxis after myeloablative HCT for malignancies partially contradict published guidelines: Single‐agent cyclosporine A (CsA) was used for matched sibling donor HCT in 47%; blood CsA levels were reported lower; the relapse risk in malignant diseases influenced GVHD prophylaxis with early withdrawal of CsA; distinct longer duration of CsA was employed in nonmalignant diseases. Most centers used additional anti‐thymocyte globulin for matched unrelated and mismatched donor HCT, but not for matched siblings. Regarding prophylaxis in nonmyeloablative conditioning (mainly for nonmalignant diseases), responses showed broad heterogeneity. High conformity was found for first‐line treatment; however, results regarding steroid‐refractory aGVHD indicate an earlier diagnosis in children. Our findings highlight the need for standardized pediatric approaches toward aGVHD prophylaxis/treatment differentiated for malignant and nonmalignant underlying diseases.

Correction: Supportive care during pediatric hematopoietic stem cell transplantation: beyond infectious diseases. A report from workshops on supportive care of the Pediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT)

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Detection and Monitoring of Lineage-Specific Chimerism by Digital Droplet PCR-Based Testing of Deletion/Insertion Polymorphisms

Analysis of specific leukocyte subsets for post-transplantation monitoring of chimerism provides greater sensitivity and clinical informativeness on dynamic changes in donor- and recipient-derived cells. Limitations of the most commonly used approach to chimerism testing relying on PCR-based analysis of microsatellite markers prompted us to assess the applicability of digital droplet (dd) PCR amplification of deletion/insertion polymorphisms (DIPs) for lineage-specific chimerism testing in the related stem cell transplantation setting, where the identification of informative markers facilitating the discrimination between donor-derived and recipient-derived cells can be challenging. We analyzed 100 genetically related patient-donor pairs by ddPCR analysis using commercially available DIP kits including large sets of polymorphic markers. At least 1 informative marker was identified in all related pairs analyzed, and 2 or more discriminating markers were detected in the majority (82%) of instances. The achievable detection limit is dependent on the number of cells available for analysis and was as low as 0.1% in the presence of ≥20,000 leukocytes available for DNA extraction. Moreover, the reproducibility and accuracy of quantitative chimerism analysis compared favorably to highly optimized microsatellite assays. Thus, the use of ddPCR-based analysis of DIP markers is an attractive approach to lineage-specific monitoring of chimerism in any allogeneic transplantation setting.

Supportive care during pediatric hematopoietic stem cell transplantation: beyond infectious diseases. A report from workshops on supportive care of the Pediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT)

Hematopoietic stem cell transplantation (HSCT) is currently the standard of care for many malignant and nonmalignant blood diseases. As several treatment-emerging acute toxicities are expected, optimal supportive measurements critically affect HSCT outcomes. The paucity of good clinical studies in supportive practices gives rise to the establishment of heterogeneous guidelines across the different centers, which hampers direct clinical comparison in multicentric studies. Aiming to harmonize the supportive care provided during the pediatric HSCT in Europe, the Pediatric Diseases Working Party (PDWP) of the European Society for Blood and Marrow Transplantation (EBMT) promoted dedicated workshops during the years 2017 and 2018. The present paper describes the resulting consensus on the management of sinusoidal obstructive syndrome, mucositis, enteral and parenteral nutrition, iron overload, and emesis during HSCT.

Management of growth failure and growth hormone deficiency after pediatric allogeneic HSCT: Endocrinologists are of importance for further guidelines and studies

Growth failure (GF) is a frequent problem after pediatric allogeneic hematopoietic stem cell transplantation (HSCT). Growth hormone deficiency (GHD) occurs in 20 to 85%, but published data on the efficacy of growth hormone treatment (GHT) are conflicting. Currently, there are no recommendations on screening for and treatment of GHD after HSCT. We aimed to describe the management of endocrine follow-up (FU)and details of GHT within European Society for Blood and Marrow Transplantation (EBMT) centers.In a retrospective questionnaire study, all EBMT centers performing pediatric HSCT were invited. Results were evaluated in correlation with the structure of endocrine aftercare (HSCT-clinicians and endocrinologists).The majority of centers (80%) reported endocrine FU by an endocrinologist - either within the HSCT-center or in a separate endocrine clinic. Fifty-four percent reported FU outside of the HSCT-center. As diagnostic tests the insulin-like growth factor IGF-I and insulin-like growth factor binding protein IGFBP3, insulin tolerance test and arginine stimulation test were most frequently used. Sixty-four percent of centers performed GHT and endocrinologists were more likely to prescribe GH (74%) compared to HSCT-clinicians (33%). The most frequent indication for GHT was GHD in 60%, with a distinct different approach of endocrinologists in comparison with HSCT-clinicians.Our study reveals substantial variation in practice and emphasizes the need for endocrine aftercare performed by dedicated endocrinologists in close collaboration with the HSCT-center. Our results indicate that the management of GHT depends on the structure of endocrine aftercare, which is important for the future development and distribution of studies and guidelines.

National Institutes of Health-Defined Chronic Graft-vs.-Host Disease in Pediatric Hematopoietic Stem Cell Transplantation Patients Correlates With Parameters of Long-Term Immune Reconstitution

Recent data revealed the importance of immune reconstitution (IR) for the evaluation of possible biomarkers in National Institutes of Health (NIH)–defined chronic graft-vs.-host disease (cGVHD) and its clinical aspects. In this large pediatric study (n = 146), we have analyzed whether cellular and humoral parameters of IR in the long-term follow-up (FU) with a special emphasis on B-cell reconstitution correlate with NIH-defined cGVHD criteria. HYPOTHESIS: we were especially interested in whether meaningful cGVHD biomarkers could be defined in a large pediatric cohort. We here demonstrate for the first time in a highly homogenous pediatric patient cohort that both cGVHD (n = 38) and its activity were associated with the perturbation of the B-cell compartment, including low frequencies of CD19⁺CD27⁺ memory B-cells and increased frequencies of circulating CD19⁺CD21^low B-cells, a well-known hyperactivated B-cell subset frequently found elevated in chronic infection and autoimmunity. Notably, resolution of cGVHD correlated with expansion of CD19⁺CD27⁺ memory B-cells and normalization of CD19⁺CD21^low B-cell frequencies. Moreover, we found that the severity of cGVHD had an impact on parameters of IR and that severe cGVHD was associated with increased CD19⁺CD21^low B-cell frequencies. When comparing the clinical characteristics of the active and non-active cGVHD patients (in detail at time of analyses), we found a correlation between activity and a higher overall severity of cGVHD, which means that in the active cGVHD patient group were more patients with a higher disease burden of cGVHD—despite similar risk profiles for cGVHD. Our data also provide solid evidence that the time point of analysis regarding both hematopoietic stem cell transplantation (HSCT) FU and cGVHD disease activity may be of critical importance for the detailed investigation of pediatric cohorts. Finally, we have proven that the differences in risk factors and patterns of IR, with cGVHD as its main confounding factor, between malignant and non-malignant diseases, are important to be considered in future studies aiming at identification of novel biomarkers for cGVHD.

Allogeneic hematopoietic stem cell transplantation from unrelated donors is associated with higher infection rates in children with acute lymphoblastic leukemia-A prospective international multicenter trial on behalf of the BFM-SG and the EBMT-PDWP

Severe infections (SI) significantly impact on non‐relapse mortality after hematopoietic stem cell transplantation (HSCT). We assessed 432 children and adolescents with acute lymphoblastic leukemia (ALL) after total body irradiation based myeloablative HSCT within the multicenter ALL‐BFM‐SCT 2003 trial for SI grade 3 or higher according to common terminology criteria for adverse events. A total 172 patients experienced at least one SI. Transplantation from matched unrelated donors (MUD) was associated with any type of SI in the pre‐engraftment period (hazard ratio [HR]: 2.57; P < .001), and with any SI between day +30 and + 100 (HR: 2.91; P = .011). Bacterial (HR: 2.24; P = .041) and fungal infections (HR: 4.06; P = .057) occurred more often in the pre‐engraftment phase and viral infections more often before day +30 (HR: 2.66; P = .007) or between day +30 and + 100 (HR: 3.89; P = .002) after HSCT from MUD as compared to matched sibling donors. Chronic GvHD was an independent risk factor for any type of SI after day +100 (HR: 2.57; P < .002). We conclude that allogeneic HSCT from MUD in children and adolescents with pediatric ALL is associated with higher infection rates, which seems attributable to an intensified GvHD prophylaxis including serotherapy and methotrexate.

Benefits and challenges with diagnosing chronic and late acute GVHD in children using the NIH consensus criteria

Chronic graft-versus-host disease (cGVHD) and late acute graft-versus-host disease (L-aGVHD) are understudied complications of allogeneic hematopoietic stem cell transplantation in children. The National Institutes of Health Consensus Criteria (NIH-CC) were designed to improve the diagnostic accuracy of cGVHD and to better classify graft-versus-host disease (GVHD) syndromes but have not been validated in patients <18 years of age. The objectives of this prospective multi-institution study were to determine: (1) whether the NIH-CC could be used to diagnose pediatric cGVHD and whether the criteria operationalize well in a multi-institution study; (2) the frequency of cGVHD and L-aGVHD in children using the NIH-CC; and (3) the clinical features and risk factors for cGVHD and L-aGVHD using the NIH-CC. Twenty-seven transplant centers enrolled 302 patients <18 years of age before conditioning and prospectively followed them for 1 year posttransplant for development of cGVHD. Centers justified their cGVHD diagnosis according to the NIH-CC using central review and a study adjudication committee. A total of 28.2% of reported cGVHD cases was reclassified, usually as L-aGVHD, following study committee review. Similar incidence of cGVHD and L-aGVHD was found (21% and 24.7%, respectively). The most common organs involved with diagnostic or distinctive manifestations of cGVHD in children include the mouth, skin, eyes, and lungs. Importantly, the 2014 NIH-CC for bronchiolitis obliterans syndrome perform poorly in children. Past acute GVHD and peripheral blood grafts are major risk factors for cGVHD and L-aGVHD, with recipients ≥12 years of age being at risk for cGVHD. Applying the NIH-CC in pediatrics is feasible and reliable; however, further refinement of the criteria specifically for children is needed.

PD-L1 and PD1 expression in post-transplantation lymphoproliferative disease (PTLD) of childhood and adolescence: An inter- and intra-individual descriptive study covering the whole spectrum of PTLD categories

Therapy of children with post-transplantation lymphoproliferative disorder (PTLD) after hematopoietic stem cell (HSCT) and solid organ transplantation (SOT) can be challenging. In this retrospective study, we investigated PD-L1 and PD1 expression in all PTLD categories of childhood and adolescence to see whether checkpoint inhibition with PD-L1/PD1 inhibitors may serve as a therapy option. We included 21 patients aged 19 years or younger (at date of transplant) with PTLD following SOT or HSCT having adequate tumor samples available (n = 29). Using immunohistochemistry, we evaluated PD-L1/PD1 expression on both tumor cells and cells of the microenvironment in all samples. Availability of consecutively matched tumor samples during 6 of 21 patients' disease courses also allowed an intra-individual assessment of PD-L1/PD1 expression. We observed lower PD-L1 and higher PD1 expression in non-destructive lesions, and higher PD-L1 and lower PD1 expression in polymorphic and, in particular, in monomorphic PTLD, mostly diffuse large B-cell lymphomas (DLBCL, n = 10/21). The amount of PD-L1- and PD1-positive cells changed in the opposite way in sequential biopsies of the same individual correlating well with the PTLD category. This is the first comprehensive pediatric study assessing PD-L1 and PD1 expression on tumor cells and in the microenvironment of PTLD including not only monomorphic, but also non-destructive early lesions. PD-L1 expression of the tumor cells inversely correlated with PD1 expression in surrounding tissues, with the highest expression in DLBCL. Since PTLD can be therapeutically challenging, our results indicate a potential efficacy of checkpoint inhibitors if standard immune- and/or chemotherapy fail or are impossible. We therefore recommend routine staining of PD-L1 and PD1 in all PTLD categories.

Gonadal Function after Busulfan Compared with Treosulfan in Children and Adolescents Undergoing Allogeneic Hematopoietic Stem Cell Transplant

Gonadal impairment is an important late effect with a significant impact on quality of life of transplanted patients. The aim of this study was to compare gonadal function after busulfan (Bu) or treosulfan (Treo) conditioning regimens in pre- and postpubertal children. This retrospective, multicenter study included children transplanted in pediatric European Society for Blood and Marrow Transplantation (EBMT) centers between 1992 and 2012 who did not receive gonadotoxic chemoradiotherapy before the transplant. We evaluated 137 patients transplanted in 25 pediatric EBMT centers. Median age at transplant was 11.04 years (range, 5 to 18); 89 patients were boys and 48 girls. Eighty-nine patients were prepubertal at transplant and 48 postpubertal. One hundred eighteen children received Bu and 19 Treo. A higher proportion of girls treated with Treo in the prepubertal stage reached spontaneous puberty compared with those treated with Bu (P = .02). Spontaneous menarche was more frequent after Treo than after Bu (P < .001). Postpubertal boys and girls treated with Treo had significantly lower luteinizing hormone levels (P = .03 and P = .04, respectively) compared with the Bu group. Frequency of gonadal damage associated with Treo was significantly lower than that observed after Bu. These results need to be confirmed in a larger population.

Changes in Immunosuppressive Treatment of Chronic Graft-versus-Host Disease: Comparison of 2 Surveys within Allogeneic Hematopoietic Stem Cell Transplant Centers in Germany, Austria, and Switzerland

Chronic graft-versus-host disease (cGVHD) remains the leading cause of late morbidity and mortality. Despite the growing number of treatment options in cGVHD, evidence remains sparse. The German-Austrian-Swiss GVHD Consortium performed a survey on clinical practice in treatment of cGVHD among transplant centers in Germany, Austria, and Switzerland in 2009 and 2018 and compared the results. The survey performed in 2009 contained 20 questions on first-line treatment and related issues and 4 questions on second-line scenarios followed by a survey on all systemic and topic treatment options known and applied, with 31 of 36 transplant centers (86%) responding. The survey in 2018 repeated 7 questions on first-line treatment and 3 questions on second-line scenarios followed by an updated survey on all current systemic treatment options known and applied, with 29 of 66 centers (43%) responding. In summary, the results show a large overlap of first-line treatment practice between centers and the 2 surveys because of a lack of new data that changes practice, except significant heterogeneity of treatment of cGVHD progressive onset type, which can be explained by the lack of trials focusing on this high-risk entity. In contrast, treatment options applied to second-line therapy vary considerably, with new agents like ibrutinib and ruxolitinib entering clinical practice. Moreover, treatment of bronchiolitis obliterans syndrome demonstrates heterogeneity in applied therapeutic options and sequence because of a lack of controlled data and different conclusions from already existing evidence. In summary, the survey results demonstrate an increasing number of treatment options applied to cGVHD accompanied by a significant heterogeneity in second-line treatment and underline the urgent need for clinical trials and registry analyses on rare entities with high mortality like progressive onset type and lung involvement of cGVHD.

Diagnostic Parameters of Adenoviremia in Pediatric Stem Cell Transplant Recipients

Despite recent progress in the diagnostic risk assessment of human adenovirus (HAdV) infections in immunocompromised patients, clinical complications mediated by these viruses continue contributing to significant morbidity and mortality, particularly in the pediatric hematopoietic allogeneic stem cell transplant (HSCT) setting. Current data highlight the importance of monitoring stool samples to assess the risk of invasive HAdV infections in children undergoing HSCT. The advent of novel, more effective antiviral treatment options might permit successful virus control even at the stage of systemic infection, thus increasing the interest in optimized HAdV monitoring in peripheral blood (PB). We have screened over 300 pediatric HCST recipients by serial monitoring of stool and PB specimens, and identified 31 cases of invasive HAdV infection by quantitative pan-adenovirus RQ-PCR analysis of consecutive PB specimens. The diagnostic parameters assessed included HAdV peak levels (PL) and the time-averaged area under the curve (AAUC) of virus copy numbers. The predictive value for patient outcome reflected by non-relapse and HAdV-related mortality was determined. The patients were assigned to quartiles based on their PL and AAUC, and the readouts were highly correlated (p < 0.0001). Non-relapse mortality in patients by AAUC quartile (lowest to highest) was 26, 50, 75, and 86%, respectively, and AAUC was strongly correlated with non-relapse mortality (p < 0.0001), while the association between PL and non-relapse mortality was less pronounced (p = 0.013). HAdV-related mortality was absent or very low in patients within the two lower quartiles of both PL and AAUC, and increased to ≥70% in the upper two quartiles. Despite the significant correlation of PL and AAUC with patient outcome, it is necessary to consider that the risk of non-relapse mortality even within the lowest quartile was still relatively high, and it might be difficult therefore to translate the results into differential treatment approaches. By contrast, the correlation with HAdV-related mortality might permit the identification of a low-risk patient subset. Nevertheless, the well-established correlation of HAdV shedding into the stool and intestinal expansion of the virus with the risk of invasive infection will expectedly remain an essential diagnostic parameter in the pediatric HSCT setting.

Post-transplant Replication of Torque Teno Virus in Granulocytes

Torque Teno virus (TTV) in humans is characterized by ubiquitous occurrence in peripheral blood (PB), without any related disease described to date. Several studies reported a significant increase of TTV plasma DNA levels in allogeneic transplant recipients, and suggested a correlation of elevated virus titers with immunosuppression and transplant-related complications. However, the site of viral replication in this setting has remained unclear. We have studied TTV in serial plasma specimens derived from 43 pediatric allogeneic hematopoietic stem cell transplantation (HSCT) recipients by RQ-PCR, and found increasing TTV-DNA levels in all patients post-transplant, with a peak around day +100 and maximum virus copy numbers reaching 4 × 10E9/ml. To assess whether the virus replicates in PB-cells, leukocyte subsets including granulocytes, monocytes, NK-cells, T- and B-lymphocytes were serially isolated by flow-sorting for TTV analysis in 19 patients. The virus was undetectable in most cell types, but was identified in granulocytes in all instances, revealing a median DNA copy number increase of 1.8 logs between days +30–100 post-transplant. Our data therefore provide evidence for TTV replication in granulocytes in this setting. In a control cohort of immunocompetent children and in HSCT recipients before day +30, TTV positivity in granulocytes was less common (33%), and the copy numbers were considerably lower. However, rising TTV replication about 2 weeks after granulocyte engraftment (>500 cells/μl) was observed suggesting that granulocyte recovery might be required for TTV expansion in severely immunosuppressed transplant recipients.

Biomarkers in chronic graft-versus-host disease: quo vadis?

Biomarkers are increasingly used for diagnosis and treatment of transplant-related complications including the first biomarker-driven interventional trials of acute graft-versus-host disease (GvHD). In contrast, the development of biomarkers of chronic GvHD (cGvHD) has lagged behind due to a broader variety of manifestations, overlap with acute GvHD, a greater variation in time to onset and maximum severity, and lack of sufficient patient numbers within prospective trials. An international workshop organized by a North-American and European consortium was held in Marseille in March 2017 with the goal to discuss strategies for future biomarker development to guide cGvHD therapy. As a result of this meeting, two areas were prioritized: the development of prognostic biomarkers for subsequent onset of moderate/severe cGvHD, and in parallel, the development of qualified clinical-grade assays for biomarker quantification. The most promising prognostic serum biomarkers are CXCL9, ST2, matrix metalloproteinase-3, osteopontin, CXCL10, CXCL11, and CD163. Urine-proteomics and cellular subsets (CD4+ T-cell subsets, NK cell subsets, and CD19+CD21low B cells) represent additional potential prognostic biomarkers of cGvHD. A joint effort is required to verify the results of numerous exploratory trials before any of the potential candidates is ready for validation and subsequent clinical application.

Intestinal Adenovirus Shedding Before Allogeneic Stem Cell Transplantation Is a Risk Factor for Invasive Infection Post-transplant

Human adenoviruses (HAdV) are a major cause of morbidity and mortality in pediatric human stem cell transplant (HSCT) recipients. Our previous studies identified the gastrointestinal tract as a site of HAdV persistence, but the role of intestinal virus shedding pre-transplant for the risk of ensuing invasive infection has not been entirely elucidated. Molecular HAdV monitoring of serial stool samples using RQ-PCR was performed in 304 children undergoing allogeneic HSCT. Analysis of stool and peripheral blood specimens was performed pre-transplant and at short intervals until day 100 post-HSCT. The virus was detected in the stool of 129 patients (42%), and 42 tested positive already before HSCT. The patients displaying HAdV shedding pre-transplant showed a significantly earlier increase of intestinal HAdV levels above the critical threshold associated with high risk of invasive infection (p<0.01). In this subset of patients, the occurrence of invasive infection characterized by viremia was significantly higher than in patients without HAdV shedding before HSCT (33% vs 7%; p<0.0001). The data demonstrate that intestinal HAdV shedding before HSCT confers a greatly increased risk for invasive infection and disseminated disease post-transplant, and highlights the need for timely HAdV monitoring and pre-emptive therapeutic considerations in HSCT recipients.

Long-term follow-up of IPEX syndrome patients after different therapeutic strategies: An international multicenter retrospective study

Background

Immunodysregulation polyendocrinopathy enteropathy x-linked(IPEX) syndromeis a monogenic autoimmune disease caused by FOXP3 mutations. Because it is a rare disease, the natural history and response to treatments, including allogeneic hematopoietic stem cell transplantation (HSCT) and immunosuppression (IS), have not been thoroughly examined.

Objective

This analysis sought to evaluate disease onset, progression, and long-term outcome of the 2 main treatments in long-term IPEX survivors.

Methods

Clinical histories of 96 patients with a genetically proven IPEX syndrome were collected from 38 institutions worldwide and retrospectively analyzed. To investigate possible factors suitable to predict the outcome, an organ involvement (OI) scoring system was developed.

Results

We confirm neonatal onset with enteropathy, type 1 diabetes, and eczema. In addition, we found less common manifestations in delayed onset patients or during disease evolution. There is no correlation between the site of mutation and the disease course or outcome, and the same genotype can present with variable phenotypes. HSCT patients (n = 58) had a median follow-up of 2.7 years (range, 1 week-15 years). Patients receiving chronic IS (n = 34) had a median follow-up of 4 years (range, 2 months-25 years). The overall survival after HSCT was 73.2% (95% CI, 59.4-83.0) and after IS was 65.1% (95% CI, 62.8-95.8). The pretreatment OI score was the only significant predictor of overall survival after transplant (P = .035) but not under IS.

Conclusions

Patients receiving chronic IS were hampered by disease recurrence or complications, impacting long-term disease-free survival. When performed in patients with a low OI score, HSCT resulted in disease resolution with better quality of life, independent of age, donor source, or conditioning regimen.

Fertility preservation issues in pediatric hematopoietic stem cell transplantation: practical approaches from the consensus of the Pediatric Diseases Working Party of the EBMT and the International BFM Study Group

Fertility preservation is an urgent challenge in the transplant setting. A panel of transplanters and fertility specialists within the Pediatric Diseases Working Party of the European Society for Blood and Marrow Transplantation (EBMT) and the International BFM Study Group provides specific guidelines. Patients and families should be informed of possible gender- and age-specific cryopreservation strategies that should be tailored according to the underlying disease, clinical condition and previous exposure to chemotherapy. Semen collection should be routinely offered to all postpubertal boys at the diagnosis of any disease requiring therapy that could potentially impair fertility. Testicular tissue collection might be offered to postpubertal boys; nevertheless, its use has been unsuccessful to date. Oocyte collection after hormonal hyperstimulation should be offered to postpubertal girls facing gonadotoxic therapies that could be delayed for the 2 weeks required for the procedure. Ovarian tissue collection could be offered to pre-/post-pubertal girls. Pregnancies have been reported after postpubertal ovarian tissue reimplantation; however, to date, no pregnancy has been reported after the reimplantation of prepubertal ovarian tissue or in vitro maturation of pre-/post-pubertal ovarian tissue. Possible future advances in reproductive medicine could change this scenario. Health authorities should prioritize fertility preservation projects in pediatric transplantation to improve patient care and quality of life.

Peripheral blood late mixed chimerism in leucocyte subpopulations following allogeneic stem cell transplantation for childhood malignancies: does it matter?

The impact of persistent mixed chimerism (MC) after haematopoietic stem cell transplantation (HSCT) remains unclarified. We investigated the incidence of MC in peripheral blood beyond day +50 after HSCT and its impact on rejection, chronic graft-versus-host disease (c-GvHD) and relapse in 161 children receiving allogeneic HSCT for haematological malignancies. The 1-year incidence of late MC was 26%. Spontaneous conversion to complete donor chimerism (CC) occurred in 43% of patients as compared to 62% after donor lymphocyte infusions. No graft rejection occurred. The 1-year incidence of c-GvHD was 20 ± 7% for MC, and 18 ± 4% for CC patients (P = 0·734). The 3-year cumulative incidence of relapse (CIR) according to chimerism status at days +50 and +100 was 22 ± 4% for CC patients vs. 22 ± 8% for MC patients (day +50; P = 0·935) and 21 ± 4% vs. 20 ± 7% (day +100; P = 0·907). Three-year CIRs in patients with persistent MC and patients with CC/limited MC were comparable (8 ± 7% vs. 19 ± 4%; P = 0·960). HSCT for acute leukaemia or myelodysplastic syndrome as secondary malignancies (hazard ratio (HR) 4·7; P = 0·008), for AML (HR 3·0; P = 0·02) and from mismatched donors (HR 3·1; P = 0·03) were independent factors associated with relapse. Our data suggest that late MC neither protects from c-GvHD nor does it reliably predict impending disease relapse.

Risk assessment of relapse by lineage-specific monitoring of chimerism in children undergoing allogeneic stem cell transplantation for acute lymphoblastic leukemia

Allogeneic hematopoietic stem cell transplantation is required as rescue therapy in about 20% of pediatric patients with acute lymphoblastic leukemia. However, the relapse rates are considerable, and relapse confers a poor outcome. Early assessment of the risk of relapse is therefore of paramount importance for the development of appropriate measures. We used the EuroChimerism approach to investigate the potential impact of lineage-specific chimerism testing for relapse-risk analysis in 162 pediatric patients with acute lymphoblastic leukemia after allogeneic stem cell transplantation in a multicenter study based on standardized transplantation protocols. Within a median observation time of 4.5 years, relapses have occurred in 41/162 patients at a median of 0.6 years after transplantation (range, 0.13-5.7 years). Prospective screening at defined consecutive time points revealed that reappearance of recipient-derived cells within the CD34(+) and CD8(+) cell subsets display the most significant association with the occurrence of relapses with hazard ratios of 5.2 (P=0.003) and 2.8 (P=0.008), respectively. The appearance of recipient cells after a period of pure donor chimerism in the CD34(+) and CD8(+) leukocyte subsets revealed dynamics indicative of a significantly elevated risk of relapse or imminent disease recurrence. Assessment of chimerism within these lineages can therefore provide complementary information for further diagnostic and, potentially, therapeutic purposes aiming at the prevention of overt relapse. This study was registered at clinical.

TRIALS

gov with the number NC01423747.

Long-term follow-up after allogeneic stem cell transplantation

BACKGROUND

Over 3000 persons undergo allogeneic hematopoietic stem-cell transplantation (allo-HSCT) in Germany every year. Advances in allo-HSCT have prolonged the survival of treated patients but have concomitantly increased the risk of long-term complications that impair their quality of life.

METHODS

This literature review of the long-term sequelae of allo-HSCT is based on pertinent articles that were retrieved by a selective search of PubMed, and on current international guidelines. Case reports were excluded from consideration.

RESULTS

Hardly any randomized clinical trials have been performed to investigate the long-term outcome of allo-HSCT, but international consensus-based guidelines have been published. 50% to 70% of patients treated with allo-HSCT develop chronic graft-versus-host disease (cGVHD) within ten years of treatment. Transplant recipients are at higher risk of infection, including the reactivation of dormant herpes viruses; therefore, vaccination is recommended, as described in the current guidelines. Gonadal dysfunction arises in up to 92% of men and up to 99% of women; its frequency depends on the timing of transplantation, on radiotherapy, and on other factors. The medications that transplant recipients need to take can impair liver function, and transfusionassociated hemosiderosis can do so as well. 40% to 50% of patients suffer from lipid metabolic disturbances that increase the risk of myocardial infarction, peripheral arterial occlusive disease, and stroke. Their life expectancy is shorter than that of the overall population.

CONCLUSION

Measures should be taken to prevent the potential long-term complications of allo-HSCT. All patients who have been treated with allo-HSCT should receive individualized, risk-adapted, and multidisciplinary follow-up care, so that any complications that arise can be correctly diagnosed and appropriately treated. Long-term follow-up care could be improved by prospective clinical trials investigating the long-term sequelae of allo-HSCT, as well as by consistent, uniform documentation of these sequelae in supraregional data registries.