Hematopoietic stem cell transplantation for inborn errors of immunity: 30-year single-center experience

Haematopoietic stem cell transplantation in children with inborn errors of immunity: A single centre experience

This study retrospectively analyzed the outcomes of 61 pediatric patients with inborn errors of immunity (IEI) who underwent hematopoietic stem cell transplantation (HSCT) between 2011 and 2023. Patients were categorized into primary immunodeficiency disorders (PIDD), primary immune dysregulation disorders (PIRD), and congenital defects of phagocyte number or function (CDP). Median ages at diagnosis and HSCT were 9 and 30 months, respectively. With a median follow-up of 51 months, the overall survival (OS) was 70%, with a 100-day post-transplant OS of 80%. Transplant-related mortality (TRM) was 29%, with rates of 42%, 22.5%, and 27% for PIRD, PIDD, and CDP, respectively. This study highlights the importance of early diagnosis and HSCT in improving survival for IEI patients, while also emphasizing the need for continuous improvements in transplant protocols to minimize TRM and enhance quality of life.

Outcomes of Hematopoietic Cell Transplantation in Children with Inborn Errors of Immunity: A Single-Center Series

Inborn errors of immunity (IEI) are a heterogenous group of rare monogenic disorders that affect innate or adaptive immunity, resulting in susceptibility to life-threatening infections and autoimmunity. Allogeneic hematopoietic cell transplantation (HCT) is a valuable curative option for children with IEI. We conducted a retrospective single-center study on the outcome of HCT in children with IEI. Primary outcome was overall survival (OS). We gathered data from 55 patients underwent HCT in the period 2014 to 2023. The indications for HCT were CGD (n = 14), HLH (n = 12), SCID (n = 10), and others (n = 19). Median age at HCT was 3 years (range 0.1-17). Donors were HLA-matched related (n = 27), haploidentical (n = 24), and cord (n = 4). The conditioning regimens were myeloablative (n = 34), reduced intensity (n = 18), or no conditioning (n = 3). After a median follow-up of 43 months (range 13-120), 2-year OS was 93%, 2-year EFS 79% and 2 year GvHD-free relapse-free survival (GRFS) was 69%. Univariate analysis showed that bone marrow source was significantly associated with better EFS and GRFS. Cumulative incidence of grade 2-4 acute and moderate/severe chronic GvHD were 21% and 13%, respectively. Incidence of graft failure was 13%. In conclusion, HCT is feasible and curative in children with IEI. Early diagnosis and referral in addition to timely treatment can further improve outcomes.

Hematopoietic cell transplantation for inborn errors of immunity: an update on approaches, outcomes and innovations

PURPOSE OF REVIEW

Allogeneic hematopoietic cell transplantation (HCT) is a curative option for many for inborn errors of immunity (IEI). This review highlights recent progress in the field of HCT for IEI.

RECENT FINDINGS

Alternative donor transplantation continues to expand donor options for patients with IEI. Reduced intensity and reduced toxicity conditioning approaches are being investigated and optimized. Immunomodulatory bridging therapies are yielding impressive progress in outcomes for primary immune regulatory disorders (PIRD) but require further study in prospective trials. Single-institution, multicenter and consortium studies have improved our understanding of factors that affect overall outcomes in IEI and outcomes in Wiskott-Aldrich syndrome (WAS), chronic granulomatous disease (CGD) and PIRD in particular. Data show that second HCT offers a viable chance of cure to some IEI patients. Late effects in IEI HCT survivors are being better characterized. Preclinical studies of chemo(radiation)-free HCT strategies hold promise for decreasing HCT toxicity.

SUMMARY

Improvements in our understanding of HCT donor choice, conditioning regimen, immunomodulatory bridging therapies, diagnostic and post-HCT surveillance testing and late effects continue to yield advancements in the field of HCT for IEI.

Successful Immune Reconstitution in a Patient with a TYK2 Deficiency after Allogeneic Stem Cell Transplantation from Unrelated Donors

A boy with primary immunodeficiency, caused by a tyrosine kinase 2 (TYK2) mutation, presented with immune defects and a lifelong history of severe infections. Our aim was to determine whether allogeneic hematopoietic stem cell transplantation (HSCT) could restore the patient's immune defenses and reduce susceptibility to infection. In the absence of a suitable HLA-matched blood relative to act as a donor, the patient received an allogeneic HSCT from unrelated donors. The patient's clinical data were analyzed in the Children's Hospital of Chongqing Medical University (Chongqing, China) before transplantation and during the 4-year follow-up period using a combination of western blotting (e.g., TYK2 and STAT levels), qRT-PCR (e.g., T cell receptor rearrangement excision circles, kappa deletion element recombination circles, and TYK2 transcript levels), and flow cytometry (e.g., lymphocyte subpopulations and CD107α secretion). We found that HSCT significantly reduced the incidence of severe infections, restored normal TKY2 levels, and reversed defects such as impaired JAK/STAT signaling in response to interferon-α or interleukin-10 treatment. Although the patient did not develop acute graft-versus-host disease (GVHD) after transplantation, he did experience chronic GVHD symptoms in a number of organs, which were effectively managed. Our findings suggest that HSCT is a feasible strategy for reconstituting the immune system in TYK2-deficient patients; however, the factors associated with GVHD and autoimmune thyroiditis development in TYK2-deficient patients undergoing HSCT warrant further investigation.

Inborn Errors of Immunity in Jordan: First Report from a Tertiary Referral Center

PURPOSE

Inborn errors of immunity (IEI) are a heterogeneous group of diseases with variable clinical phenotypes. This study was conducted to describe the epidemiology, clinical presentations, treatment, and outcome of IEI in Jordanian children.

METHODS

A retrospective data analysis was conducted for children under 15 years diagnosed with IEI from the pediatric Allergy, Immunology, and Rheumatology Division-based registry at Queen Rania Children's Hospital, Amman, Jordan, between 2010 and 2022.

RESULTS

A total of 467 patients, 263 (56.3%) males and 204 (43.7%) females, were diagnosed with IEI. The mean age at symptom onset was 18 months (1 week to 144 months), a positive family history of IEI was reported in 43.5%, and the consanguinity rate was 47.9%. The most common IEI category was immunodeficiencies affecting cellular and humoral immunity at 33.2%, followed by predominantly antibody deficiencies at 16.9%. The overall median diagnostic delay (range) was 6 (0-135) months; patients with a positive family history of IEI had a statistically significant shorter diagnostic delay. Pulmonary and gastrointestinal clinical features were the most common at 55.2% and 45.6%, respectively. The overall mortality was 33.2%; the highest rate was reported in severe combined immunodeficiency at 56.2%.

CONCLUSIONS

The high minimal estimated IEI prevalence at 16.2/100,000 Jordanian children compared to the regional and worldwide data, with the diversities in clinical presentation and distribution of IEI categories in our cohort point to unique features of IEI in Jordanian children, call for national registry establishment, regional and international collaborative networks.