Hematopoietic cell transplantation in chronic granulomatous disease: a study of 712 children and adults.

Chronic granulomatous disease (CGD) is a primary immunodeficiency resulting in life-threatening infections and inflammatory complications. Allogeneic hematopoietic cell transplantation (allo-HCT) can cure the disease, but the indication to transplant remains controversial. We performed a retrospective multicenter study of 712 patients with CGD who underwent allo-HCT transplantation from March 1993 through December 2018. We studied 635 children (aged <18 years) and 77 adults. Median follow-up was 45 months. Median age at transplantation was 7 years (range, 0.1-48.6). Kaplan-Meier estimates of overall survival (OS) and event-free survival (EFS) at 3 years were 85.7% and 75.8%, respectively. In multivariate analysis, older age was associated with reduced survival and increased chronic graft-versus-host disease. Nevertheless, OS and EFS at 3 years for patients ≥18 years were 76% and 69%, respectively. Use of 1-antigen-mismatched donors was associated with reduced OS and EFS . No significant difference was found in OS, but a significantly reduced EFS was noted in the small group of patients who received a transplant from a donor with a >1 antigen mismatch. Choice of conditioning regimen did not influence OS or EFS. In summary, we report an excellent outcome after allo-HCT in CGD, with low incidence of graft failure and mortality in all ages. Older patients and recipients of 1-antigen-mismatched grafts had a less favorable outcome. Transplantation should be strongly considered at a younger age and particularly in the presence of a well-matched donor.

Transfer and loss of allergen-specific responses via stem cell transplantation: A prospective observational study.

BACKGROUND: Currently, no estimates can be made on the impact of hematopoietic stem cell transplantation on allergy transfer or cure of the disease. By using component-resolved diagnosis, we prospectively investigated 50 donor-recipient pairs undergoing allogeneic stem cell transplantation. This allowed calculating the rate of transfer or maintenance of allergen-specific responses in the context of stem cell transplantation. METHODS: Allergen-specific IgE and IgG to 156 allergens was measured pretransplantation in 50 donors and recipients and at 6, 12 and 24 months in recipients post-transplantation by allergen microarray. Based on a mixed effects model, we determined risks of transfer of allergen-specific IgE or IgG responses 24 months post-transplantation. RESULTS: After undergoing stem cell transplantation, 94% of allergen-specific IgE responses were lost. Two years post-transplantation, recipients' allergen-specific IgE was significantly linked to the pretransplantation donor or recipient status. The estimated risk to transfer and maintain individual IgE responses to allergens by stem cell transplantation was 1.7% and 2.3%, respectively. Allergen-specific IgG, which served as a surrogate marker of maintaining protective IgG responses, was highly associated with the donor's (31.6%) or the recipient's (28%) pretransplantation response. CONCLUSION: Hematopoietic stem cell transplantation profoundly reduces allergen-specific IgE responses but also comes with a considerable risk to transfer allergen-specific immune responses. These findings facilitate clinical decision-making regarding allergic diseases in the context of hematopoietic stem cell transplantation. In addition, it provides prospective data to estimate the risk of transmitting allergen-specific responses via hematopoietic stem cell transplantation.

Hematopoietic Stem Cell Transplantation as Treatment for Patients with DOCK8 Deficiency.

BACKGROUND: Biallelic variations in the dedicator of cytokinesis 8 (DOCK8) gene cause a combined immunodeficiency with eczema, recurrent bacterial and viral infections, and malignancy. Natural disease outcome is dismal, but allogeneic hematopoietic stem cell transplantation (HSCT) can cure the disease. OBJECTIVE: To determine outcome of HSCT for DOCK8 deficiency and define possible outcome variables. METHODS: We performed a retrospective study of the results of HSCT in a large international cohort of DOCK8-deficient patients. RESULTS: We identified 81 patients from 22 centers transplanted at a median age of 9.7 years (range, 0.7-27.2 years) between 1995 and 2015. After median follow-up of 26 months (range, 3-135 months), 68 (84%) patients are alive. Severe acute (III-IV) or chronic graft versus host disease occurred in 11% and 10%, respectively. Causes of death were infections (n = 5), graft versus host disease (5), multiorgan failure (2), and preexistent lymphoma (1). Survival after matched related (n = 40) or unrelated (35) HSCT was 89% and 81%, respectively. Reduced-toxicity conditioning based on either treosulfan or reduced-dose busulfan resulted in superior survival compared with fully myeloablative busulfan-based regimens (97% vs 78%; P = .049). Ninety-six percent of patients younger than 8 years at HSCT survived, compared with 78% of those 8 years and older (P = .06). Of the 73 patients with chimerism data available, 65 (89%) had more than 90% donor T-cell chimerism at last follow-up. Not all disease manifestations responded equally well to HSCT: eczema, infections, and mollusca resolved quicker than food allergies or failure to thrive. CONCLUSIONS: HSCT is curative in most DOCK8-deficient patients, confirming this approach as the treatment of choice. HSCT using a reduced-toxicity regimen may offer the best chance for survival.

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.

Antimicrobial Resistance in Gram-Negative Rods Causing Bacteremia in Hematopoietic Stem Cell Transplant Recipients: Intercontinental Prospective Study of the Infectious Diseases Working Party of the European Bone Marrow Transplantation Group.

BACKGROUND: This intercontinental study aimed to study gram-negative rod (GNR) resistance in hematopoietic stem cell transplantation (HSCT). METHODS: GNR bacteremias occurring during 6 months post-HSCT (February 2014-May 2015) were prospectively collected, and analyzed for rates and risk factors for resistance to fluoroquinolones, noncarbapenem anti-Pseudomonas ß-lactams (noncarbapenems), carbapenems, and multidrug resistance. RESULTS: Sixty-five HSCT centers from 25 countries in Europe, Australia, and Asia reported data on 655 GNR episodes and 704 pathogens in 591 patients (Enterobacteriaceae, 73%; nonfermentative rods, 24%; and 3% others). Half of GNRs were fluoroquinolone and noncarbapenem resistant; 18.5% carbapenem resistant; 35.2% multidrug resistant. The total resistance rates were higher in allogeneic HSCT (allo-HSCT) vs autologous HSCT (auto-HSCT) patients (P < .001) but similar in community-acquired infections. Noncarbapenem resistance and multidrug resistance were higher in auto-HSCT patients in centers providing vs not providing fluoroquinolone prophylaxis (P < .01). Resistance rates were higher in southeast vs northwest Europe and similar in children and adults, excluding higher fluoroquinolone- and ß-lactam/ß-lactamase inhibitor resistance rates in allo-HSCT adults. Non-Klebsiella Enterobacteriaceae were rarely carbapenem resistant. Multivariable analysis revealed resistance risk factors in allo-HSCT patients: fluoroquinolone resistance: adult, prolonged neutropenia, breakthrough on fluoroquinolones; noncarbapenem resistance: hospital-acquired infection, breakthrough on noncarbapenems or other antibiotics (excluding fluoroquinolones, noncarbapenems, carbapenems), donor type; carbapenem resistance: breakthrough on carbapenem, longer hospitalization, intensive care unit, previous other antibiotic therapy; multidrug resistance: longer hospitalization, breakthrough on ß-lactam/ß-lactamase inhibitors, and carbapenems. Inappropriate empiric therapy and mortality were significantly more common in infections caused by resistant bacteria. CONCLUSIONS: Our data question the recommendation for fluoroquinolone prophylaxis and call for reassessment of local empiric antibiotic protocols. Knowledge of pathogen-specific resistance enables early appropriate empiric therapy. Monitoring of resistance is crucial. CLINICAL TRIALS REGISTRATION: NCT02257931.

Haematopoietic stem cell transplantation for refractory Langerhans cell histiocytosis: outcome by intensity of conditioning.

Patients with Langerhans cell histiocytosis (LCH) refractory to conventional chemotherapy have a poor outcome. There are currently two promising treatment strategies for high-risk patients: the first involves the combination of 2-chlorodeoxyadenosine and cytarabine; the other approach is allogeneic haematopoietic stem cell transplantation (HSCT). Here we evaluated 87 patients with high-risk LCH who were transplanted between 1990 and 2013. Prior to the year 2000, most patients underwent HSCT following myeloablative conditioning (MAC): only 5 of 20 patients (25%) survived with a high rate (55%) of transplant-related mortality (TRM). After the year 2000 an increasing number of patients underwent HSCT with reduced intensity conditioning (RIC): 49/67 (73%) patients survived, however, the improved survival was not overtly achieved by the introduction of RIC regimens with similar 3-year probability of survival after MAC (77%) and RIC transplantation (71%). There was no significant difference in TRM by conditioning regimen intensity but relapse rates were higher after RIC compared to MAC regimens (28% vs. 8%, P = 0·02), although most patients relapsing after RIC transplantation could be salvaged with further chemotherapy. HSCT may be a curative approach in 3 out of 4 patients with high risk LCH refractory to chemotherapy: the optimal choice of HSCT conditioning remains uncertain.

Response to rituximab-based therapy and risk factor analysis in Epstein Barr Virus-related lymphoproliferative disorder after hematopoietic stem cell transplant in children and adults: a study from the Infectious Diseases Working Party of the European Group for Blood and Marrow Transplantation.

BACKGROUND: The objective of this analysis was to investigate prognostic factors that influence the outcome of Epstein-Barr virus (EBV)-related posttransplant lymphoproliferative disorder (PTLD) after a rituximab-based treatment in the allogeneic hematopoietic stem cell transplant (HSCT) setting. METHODS: A total of 4466 allogeneic HSCTs performed between 1999 and 2011 in 19 European Group for Blood and Marrow Transplantation centers were retrospectively analyzed for PTLD, either biopsy-proven or probable disease. RESULTS: One hundred forty-four cases of PTLD were identified, indicating an overall EBV-related PTLD frequency of 3.22%, ranging from 1.16% for matched-family donor, 2.86% for mismatched family donor, 3.97% in matched unrelated donors, and 11.24% in mismatched unrelated donor recipients. In total, 69.4% patients survived PTLD. Multivariable analysis showed that a poor response of PTLD to rituximab was associated with an age ≥30 years, involvement of extralymphoid tissue, acute GVHD, and a lack of reduction of immunosuppression upon PTLD diagnosis. In the prognostic model, the PTLD mortality increased with the increasing number of factors: 0-1, 2, or 3 factors being associated with mortality of 7%, 37%, and 72%, respectively (P < .0001). Immunosuppression tapering was associated with a lower PTLD mortality (16% vs 39%), and a decrease of EBV DNAemia in peripheral blood during therapy was predictive of better survival. CONCLUSIONS: More than two-thirds of patients with EBV-related PTLD survived after rituximab-based treatment. Reduction of immunosuppression was associated with improved outcome, whereas older age, extranodal disease, and acute graft-vs-host disease predicted poor outcome.

Short-term in-vitro expansion improves monitoring and allows affordable generation of virus-specific T-cells against several viruses for a broad clinical application.

Adenoviral infections are a major cause of morbidity and mortality after allogeneic hematopoietic stem cell transplantation (HSCT) in pediatric patients. Adoptive transfer of donor-derived human adenovirus (HAdV)-specific T-cells represents a promising treatment option. However, the difficulty in identifying and selecting rare HAdV-specific T-cells, and the short time span between patients at high risk for invasive infection and viremia are major limitations. We therefore developed an IL-15-driven 6 to 12 day short-term protocol for in vitro detection of HAdV-specific T cells, as revealed by known MHC class I multimers and a newly identified adenoviral CD8 T-cell epitope derived from the E1A protein for the frequent HLA-type A*02∶01 and IFN-γ. Using this novel and improved diagnostic approach we observed a correlation between adenoviral load and reconstitution of CD8(+) and CD4(+) HAdV-specific T-cells including central memory cells in HSCT-patients. Adaption of the 12-day protocol to good manufacturing practice conditions resulted in a 2.6-log (mean) expansion of HAdV-specific T-cells displaying high cytolytic activity (4-fold) compared to controls and low or absent alloreactivity. Similar protocols successfully identified and rapidly expanded CMV-, EBV-, and BKV-specific T-cells. Our approach provides a powerful clinical-grade convertible tool for rapid and cost-effective detection and enrichment of multiple virus-specific T-cells that may facilitate broad clinical application.