Transplantation of Hematopoietic Stem Cells for Primary Immunodeficiencies in Brazil: Challenges in Treating Rare Diseases in Developing Countries

Newborn Screening Followed By Early Treatment is Essential to Improve Survival in SCID

Severe combined immunodeficiency (SCID) is a heterogeneous genetic disease characterized by severe T-cell lymphopenia with a profound impairment of T- and B-cells' function and, in some types, also NK cells. Hematopoietic cell transplantation (HCT) is the only curative treatment currently available in Brazil. Late diagnosis and treatment are the main factors affecting the survival of these children. This study aims to describe the demographic, phenotypic, genotypic, and clinical characteristics of twenty SCID patients (including typical SCID, leaky-SCID, and Omenn Syndrome) followed at a Brazilian referral center and correlate these data with their clinical outcome. The children were analyzed into two groups: patients diagnosed early by newborn screening (NBS) or family history, n = 7, and patients with late diagnosis, by clinical presentation, n = 13. The 2-year overall survival (OS) of the late group was 29.2%, in contrast to the 2-year OS of the early diagnosis group of 71.4% (p = 0.053). However, despite early diagnosis in the first group, timely access to HCT was delayed, with a median of 11 months. This research reveals that survival depends not only on timely diagnosis but also on early definitive treatment. To improve SCID survival rates, developing countries need public policies that allow rapid access to curative treatment for these patients.

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.

Haploidentical hematopoietic stem cell transplantation using post-transplant cyclophosphamide in patients with inborn errors of immunity: Experience in a reference center in Colombia

INTRODUCTION

Inborn errors of immunity is a diverse group of rare diseases caused by over 400 genetic mutations affecting the immune system and increasing infection susceptibility, autoimmunity, and malignancy. Hematopoietic stem cell transplantation offers a curative option for some inborn errors of immunity, with haploidentical donors providing a viable alternative when identical donors are unavailable.

OBJECTIVE

To determine survival, usefulness of weekly chimerism monitoring, immune reconstitution, and complications in patients with inborn errors of immunity who underwent haploidentical hematopoietic stem cell transplantation at a reference center in Colombia.

MATERIALS AND METHODS

We conducted a retrospective and observational study of a case series of pediatric patients who underwent haploidentical hematopoietic stem cell transplantation with post-transplant cyclophosphamide and follow-up with weekly chimerism. Survival analysis was performed using the Kaplan-Meier method.

RESULTS

Sixteen patients with haploidentical familial donor transplantation were included. The most frequent diagnosis was severe combined immunodeficiency (n=5). Eleven out of seventeen patients received a non-myeloablative conditioning regimen. Twelve out of sixteen patients developed acute graft-versus-host disease. Out of these, 3 corresponded to grades III-IV. Post-transplant infections affected 14 of the subjects, predominating bacterial agents. Median T-cell chimerism was greater than 80% during the follow-up. Reconstitution of B and T lymphocytes was achieved in more than 80%. Overall survival at five years was 81%. Survival at 100 days was 94%.

CONCLUSION

Haploidentical hematopoietic stem cell transplantation using post-transplant cyclophosphamide is a viable alternative for inborn errors of immunity when an identical donor is unavailable. Serial chimerism monitoring is useful for graft follow-up.

The Latin American Society for Immunodeficiencies Registry

Purpose - The Latin American Society of Immunodeficiencies (LASID) Registry was established in 2009 to collect data on Inborn Errors of Immunity (IEI) patients in the region. Although several reports have been published regarding LASID data, this is the first report of the entire dataset. Methods - The European Society of Immunodeficiencies (ESID) donated the online platform in 2008. Data was collected from participating centers from Apr 13, 2009, to Dec 31, 2022, and included demographic, clinical, and follow-up information. Results - A total of 9307 patients were included in the database. At the end of the study period, 8,805 patients were alive or lost to follow-up, and 502 were deceased. The most common type of IEI was predominantly antibody deficiency (PAD, 60.35%), and selective IgA deficiency was the most frequent diagnosis (1627 patients, 17.48%), followed by Common Variable Immune Deficiency (CVID, 1191 patients). Most patients (78.16%) were ≤ 18 years old at inclusion, and the median age at diagnosis was 4.77 years. The median time to diagnosis was 5.04 years. Antibiotics were prescribed in 32.3% of visits, followed by immunoglobulins (29.49% ). Hematopoietic stem cell transplantation was performed in 5.03% of patients. Omenn syndrome was the most common disease in deceased patients, with a mortality rate of 52.63%. Conclusion - This study contributes to our understanding of IEIs in Latin America and highlights the importance of early diagnosis, appropriate treatments, and improved data collection to optimize patient outcome.

Survival After Hematopoietic Stem Cell Transplantation in Severe Combined Immunodeficiency (SCID): A Worldwide Review of the Prognostic Variables

This study aims to perform an extensive review of the literature that evaluates various factors that affect the survival rates of patients with severe combined immunodeficiency (SCID) after hematopoietic stem cell transplantation (HSCT) in developed and developing countries. An extensive search of the literature was made in four different databases (PubMed, Embase, Scopus, and Web of Science). The search was carried out in December 2022 and updated in July 2023, and the terms such as "hematopoietic stem cell transplantation," "bone marrow transplant," "mortality," "opportunistic infections," and "survival" associated with "severe combined immunodeficiency" were sought based on the MeSH terms. The language of the articles was "English," and only articles published from 2000 onwards were selected. Twenty-three articles fulfilled the inclusion criteria for review and data extraction. The data collected corroborates that early HSCT, but above all, HSCT in patients without active infections, is related to better overall survival. The universal implementation of newborn screening for SCID will be a fundamental pillar for enabling most transplants to be carried out in this "ideal scenario" at an early age and free from infection. HSCT with an HLA-identical sibling donor is also associated with better survival rates, but this is the least common scenario. For this reason, transplantation with matched unrelated donors (MUD) and mismatched related donors (mMRD/Haploidentical) appear as alternatives. The results obtained with MUD are improving and show survival rates similar to those of MSD, as well as they do not require manipulation of the graft with expensive technologies. However, they still have high rates of complications after HSCT. Transplants with mMRD/Haplo are performed just in a few large centers because of the high costs of the technology to perform CD3/CD19 depletion and TCRαβ/CD19 depletion or CD34 + selection techniques in vitro. The new possibility of in vivo T cell depletion using post-transplant cyclophosphamide could also be a viable alternative for performing mMRD transplants in centers that do not have this technology, especially in developing countries.

Changing outcomes of stem cell transplantation in primary immunodeficiencies: Results from a tertiary-care charitable trust hospital in Mumbai

Background

Hematopoietic stem cell transplantation in primary immunodeficiency disorders has come a long way since the first transplant in 1968. In India, pediatric stem cell transplantation long-term survival outcomes range from 62.5% to 75%, compared to 90% in high-income countries.

Objective

We present single-center data of primary immunodeficiency transplants with immune-reconstitution evaluation after transplantation from a charitable trust hospital.

Methods

Retrospective data of children transplanted for primary immunodeficiency disorders from March 2019 to March 2022 in a newly established transplant unit were collected. Data of pretransplant infections and comorbidities, surveillance for carbapenem-resistant Enterobacteriaceae, transplant characteristics, donor source, graft-versus-host disease, posttransplant infections, immune reconstitution, overall survival at 1 year, and immunodeficiency-free survival were collated.

Results

Twenty-one patients underwent transplantation for primary immunodeficiency disorders. The median age at transplantation was 3 years and 5 months (range, 7 months to 17 years). Seventy-five percent of the cohort had organ involvement, with lung being the most common organ involved, followed by central nervous system. Fifty-two percent of children had peritransplant infections, with most of them recognized at the pretransplant assessment. Among 20 of 21 children with engraftment, 94% had complete chimerism initially, with 33% developing mixed chimerism over time. The median duration of immunosuppression was 3 months after transplantation, and only 1 child required systemic graft-versus-host disease treatment for more than a year. Immune-reconstitution showed good T-cell recovery at 3 months and naive T-cell production at 6 months. There was no regimen-related or sepsis-related mortality. Overall survival of the cohort was 95% at 1-year follow-up. Immunodeficiency-free survival was 86% after a median follow-up of 20 months.

Conclusions

Immunodeficiency-free and graft-versus-host disease-free survival can be achieved in the majority of children with primary immunodeficiencies using enhanced supportive care and the latest transplantation algorithms.

Allogeneic Hematopoietic Stem Cell Transplantation Activity in Inborn Errors of Immunity in Russian Federation

PURPOSE

Allogeneic hematopoietic stem cell transplantation (HSCT) is an established therapy for many inborn errors of immunity (IEI). The indications for HSCT have expanded over the last decade. The study aimed to collect and analyze the data on HSCT activity in IEI in Russia.

METHODS

The data were collected from the Russian Primary Immunodeficiency Registry and complemented with information from five Russian pediatric transplant centers. Patients diagnosed with IEI by the age of 18 years and who received allogeneic HSCT by the end of 2020 were included.

RESULTS

From 1997 to 2020, 454 patients with IEI received 514 allogeneic HSCT. The median number of HSCTs per year has risen from 3 in 1997-2009 to 60 in 2015-2020. The most common groups of IEI were immunodeficiency affecting cellular and humoral immunity (26%), combined immunodeficiency with associated/syndromic features (28%), phagocyte defects (21%), and diseases of immune dysregulation (17%). The distribution of IEI diagnosis has changed: before 2012, the majority (65%) had severe combined immunodeficiency (SCID) and hemophagocytic lymphohistiocytosis (HLH), and after 2012, only 24% had SCID and HLH. Of 513 HSCTs, 48.5% were performed from matched-unrelated, 36.5% from mismatched-related (MMRD), and 15% from matched-related donors. In 349 transplants T-cell depletion was used: 325 TCRαβ/CD19+ depletion, 39 post-transplant cyclophosphamide, and 27 other. The proportion of MMRD has risen over the recent years.

CONCLUSION

The practice of HSCT in IEI has been changing in Russia. Expanding indications to HSCT and SCID newborn screening implementation may necessitate additional transplant beds for IEI in Russia.

SCID and Other Inborn Errors of Immunity with Low TRECs - the Brazilian Experience

Severe combined immunodeficiency, SCID, is a pediatric emergency that represents the most critical group of inborn errors of immunity (IEI). Affected infants present with early onset life-threatening infections due to absent or non-functional T cells. Without early diagnosis and curative treatment, most die in early infancy. As most affected infants appear healthy at birth, newborn screening (NBS) is essential to identify and treat patients before the onset of symptoms. Here, we report 47 Brazilian patients investigated between 2009 and 2020 for SCID due to either a positive family history and/or clinical impression and low TRECs. Based on clinical presentation, laboratory finding, and genetic information, 24 patients were diagnosed as typical SCID, 14 as leaky SCID, and 6 as Omenn syndrome; 2 patients had non-SCID IEI, and 1 remained undefined. Disease onset median age was 2 months, but at the time of diagnosis and treatment, median ages were 6.5 and 11.5 months, respectively, revealing considerable delay which affected negatively treatment success. While overall survival was 51.1%, only 66.7% (30/45) lived long enough to undergo hematopoietic stem-cell transplantation, which was successful in 70% of cases. Forty-three of 47 (91.5%) patients underwent genetic testing, with a 65.1% success rate. Even though our patients did not come from the NBS programs, the diagnosis of SCID improved in Brazil during the pilot programs, likely due to improved medical education. However, we estimate that at least 80% of SCID cases are still missed. NBS-SCID started to be universally implemented in the city of São Paulo in May 2021, and it is our hope that other cities will follow, leading to early diagnosis and higher survival of SCID patients in Brazil.

Hematopoietic Cell Transplantation for Inborn Errors of Immunity Other than Severe Combined Immunodeficiency in Japan: Retrospective Analysis for 1985-2016

PURPOSE

Hematopoietic cell transplantation (HCT) is a curative therapy for most patients with inborn errors of immunity (IEI). We conducted a nationwide study on HCT for patients with IEI other than severe combined immunodeficiency (non-SCID) in Japan.

METHODS

Data from the Japanese national database (Transplant Registry Unified Management Program, TRUMP) for 566 patients with non-SCID IEI, who underwent their first HCT between 1985 and 2016, were retrospectively analyzed.

RESULTS

The 10-year overall survival (OS) and event-free survival (EFS) were 74% and 64%, respectively. The 10-year OS for HCT from unrelated bone marrow (URBM), accounting for 39% of HCTs, was comparable to that for HCT from matched sibling donor (MSD), 79% and 81%, respectively. HCT from unrelated cord blood (URCB), accounting for 28% of HCTs, was also common, with a 10-year OS of 69% but less robust engraftment. The intensity of conditioning was not associated with OS or neutrophil recovery; however, myeloablative conditioning was more frequently associated with infection-related death. Patients who received myeloablative irradiation showed poor OS. Multivariate analyses revealed that HCT in 1985-1995 (hazard ratio [HR], 2.0; P = 0.03), URCB (HR, 2.0; P = 0.01), and related donor other than MSD (ORD) (HR, 2.9; P < 0.001) were associated with poor OS, and URCB (HR, 3.6; P < 0.001) and ORD (HR, 2.7; P = 0.02) showed a higher incidence of retransplantation.

CONCLUSIONS

We present the 1985-2016 status of HCT for non-SCID IEI in Japan with sufficient statistical power, highlighting the potential of URBM as an alternative donor and the feasibility of reduced intensity conditioning.

Multicenter Outcome of Hematopoietic Stem Cell Transplantation for Primary Immune Deficiency Disorders in India

Background

Hematopoietic stem cell transplantation (HSCT) is the curative option for many primary immune deficiency disorders (PID). In the last 5 years, increased awareness, availability of diagnostics based on flow cytometry, genetic testing, improved supportive care, use of reduced toxicity conditioning, and success of haploidentical donor HSCT have improved access to HSCT for children with PID in India. We present results on children with PID who underwent HSCT across India and the factors that influenced outcome.

Patients and Methods

We collected retrospective data on the outcome of HSCT for PID from seven centers. We analyzed the impact of the type of PID, conditioning regimen, time period of HSCT- before or after January 2016, graft versus host disease prophylaxis, cause of mortality and overall survival.

Results

A total of 228 children underwent HSCT for PID at a median age of 12 months (range, 1 to 220 months) with a median follow up of 14.4 months. Infants accounted for 51.3% of the cohort and the male female ratio was 3:1. SCID (25%) and HLH (25%) were the more frequent diagnoses. Matched family donor was available in 36.4% and 44.3% children had a haploidentical HSCT. Reduced and myeloablative conditioning regimens were used with 64% children receiving a treosulfan based conditioning regimen. Peripheral blood stem cells were the predominant graft source at 69.3%. The survival in infants (60.2%) was inferior to children aged over 1 year (75.7% p value = 0.01). Children with Wiskott Aldrich syndrome (74.3%) and chronic granulomatous disease (82.6%) had the best outcomes. The survival was superior in children receiving HSCT from a matched sibling (78%) versus an alternate donor HSCT (61% p value = 0.04). In the cohort transplanted after January 2016 survival improved from 26.8% to 77.5% (p value = 0.00). Infection remains the main cause of mortality at in over 50% children. The 5-year overall survival rate was 68%.

Conclusion

Survival of children with PID undergoing HSCT in India has improved dramatically in last 5 years. Alternate donor HSCT is now feasible and has made a therapeutic option accessible to all children with PID.

Hematopoietic Stem Cell Transplantation in Children with Inborn Errors of Immunity: a Multi-center Experience in Colombia

PURPOSE

To characterize the pediatric population with inborn errors of immunity (IEI) that was treated with hematopoietic stem cell transplantation (HSCT) in three reference centers in Colombia. What have been the characteristics and outcomes of hematopoietic stem cell transplantation in pediatric patients with inborn errors of immunity in three reference care centers in Colombia between 2007 and 2018?

METHODS

We conducted an observational, retrospective cohort study in children with a diagnosis of IEI who underwent HSCT between 2007 and 2018.

RESULTS

Forty-seven patients were identified, and 5 were re-transplanted. Sixty-eight percent were male. The median age at diagnosis was 0.6 years, and for HSCT was 1.4 years. The most common diseases were chronic granulomatous disease (38%) followed by severe combined immune deficiencies (19%) and hemophagocytic lymphohistiocytosis (15%). Cord blood donors were the most used source of HSCT (44%). T cell-replete grafts from haploidentical donors using post-transplantation cyclophosphamide represent 37% of the cohort. All patients received conditioning, 62% with a non-myeloablative regimen. Calcineurin inhibitors were the main graft-versus-host disease prophylaxis (63.8%). Acute graft-versus-host disease developed in 35% of the total patients. The most frequent post-transplant infections were viral and fungal infections. The 1-year overall survival rates for the patients who received HSCT from identical, haploidentical, and cord sources were 80%, 72%, and 63%, respectively. The 5-year overall survival was 63%.

CONCLUSIONS

HSCT is a curative treatment option for some IEI and can be performed with any donor type. Early and timely treatment in referral centers can improve survival.

Gene therapy for severe combined immunodeficiencies and beyond

This review describes how gene therapy of severe combined immunodeficiency became a reality, primarily based on the expected selective advantage conferred by transduction of hematopoietic progenitor cells. Thus, it resulted in a progressive extension to the treatment of other primary immunodeficiencies.

Ex vivo retrovirally mediated gene therapy has been shown within the last 20 yr to correct the T cell immunodeficiency caused by γc-deficiency (SCID X1) and adenosine deaminase (ADA) deficiency. The rationale was brought up by the observation of the revertant of SCIDX1 and ADA deficiency as a kind of natural gene therapy. Nevertheless, the first attempts of gene therapy for SCID X1 were associated with insertional mutagenesis causing leukemia, because the viral enhancer induced transactivation of oncogenes. Removal of this element and use of a promoter instead led to safer but still efficacious gene therapy. It was observed that a fully diversified T cell repertoire could be generated by a limited set (<1,000) of progenitor cells. Further advances in gene transfer technology, including the use of lentiviral vectors, has led to success in the treatment of Wiskott–Aldrich syndrome, while further applications are pending. Genome editing of the mutated gene may be envisaged as an alternative strategy to treat SCID diseases.

Meta-analysis of hematopoietic stem cell transplantation in major histocompatibility complex class II deficiency

Major histocompatibility complex class II deficiency is a rare case of PID. Specific recommendations for hematopoietic stem cell transplant, the only curative treatment option, are still lacking. This meta-analysis aims to identify the factors associated with better prognosis in these patients. Thirteen articles reporting 63 patients with major histocompatibility complex class II deficiency that underwent hematopoietic stem cell transplant were included. The median age for hematopoietic stem cell transplant was 18 months. The most common source of transplant was bone marrow, with alternative sources as umbilical cord blood emerging during recent years. The highest proportion of engraftment was seen with umbilical cord. Engraftment was higher in patients with matched donors, with better overall survival in patients with reduced-intensity conditioning. Graft-vs-host disease developed in 65% of the patients, with grades I-II being the most frequently encountered. There was a higher mortality in patients with myeloablative conditioning and no engraftment. There was an inverse correlation between survival and stage of graft-vs-host disease. The main cause of mortality was infectious disease, mostly secondary to viral infections. Ideally, matched grafts should be used, and reduced-intensity conditioning should be considered to reduce early post-transplant complications. GVHD and viral prophylaxis are fundamental.

Haploidentical stem cell transplantation with post-transplant cyclophosphamide for osteopetrosis and other nonmalignant diseases

Allogeneic hematopoietic stem cell transplantation (HSCT) is curative for a variety of nonmalignant disorders including osteopetrosis, bone marrow failures, and immune deficiencies. Haploidentical HSCT is a readily available option in the absence of a matched donor, but engraftment failure and other post-transplant complications are a concern. Post-transplant cyclophosphamide (PT-Cy) regimens are gaining popularity and recent reports show promising results. We report our experience with nine pediatric patients with nonmalignant diseases who were transplanted from a haploidentical donor with PT-Cy. From 2015 to 2019, nine children with nonmalignant diseases underwent haploidentical HSCT with PT-Cy, two as a second transplant and seven as primary grafts after upfront serotherapy and busulfan-based myeloablative conditioning. Patient’s diseases included osteopetrosis (n = 5), congenital amegakaryocytic thrombocytopenia (n = 2), hemophagocytic lymphohistiocytosis (n = 1), and Wiskott Aldrich syndrome (n = 1). Two patients failed to engraft following upfront PT-Cy transplants, one was salvaged with a second PT-Cy transplant, and the other with a CD34+ selected graft. None of the patients suffered from graft-versus-host disease. Three patients died from early posttransplant infectious complications and six patients are alive and well. In conclusion, haploidentical HSCT with PT-Cy is a feasible option for pediatric patients with nonmalignant diseases lacking a matched donor.

Outcomes after Haploidentical Stem Cell Transplantation with Post-Transplantation Cyclophosphamide in Patients with Primary Immunodeficiency Diseases

Allogeneic hematopoietic stem cell transplantation (HCT) can cure primary immunodeficiency diseases (PID). When a HLA-matched donor is not available, a haploidentical family donor may be considered. The use of T cell-replete haploidentical HCT with post-transplantation cyclophosphamide (haplo-PTCy) in children with PID has been reported in few case series. A donor is usually readily available, and haplo-PTCy can be used in urgent cases. We studied the outcomes of 73 patients with PID who underwent haplo-PTCy, including 55 patients who did so as a first transplantation and 18 who did so as a salvage transplantation after graft failure of previous HCT. The median patient age was 1.6 years. Most of the children were male (n = 54) and had active infection at the time of transplantation (n = 50); 10 children had severe organ damage. The diagnosis was severe combined immunodeficiency (SCID) in 34 patients and non-SCID in 39 (Wiskott-Aldrich syndrome; n = 14; chronic granulomatous disease, n = 10; other PID, n = 15). The median duration of follow-up of survivors was 2 years. The cumulative incidence of neutrophil recovery was 88% in the SCID group and 84% in non-SCID group and was 81% for first transplantations and 83% after a salvage graft. At 100 days, the cumulative incidence of acute GVHD grade II-IV and III-IV was 33% and 14%, respectively. The majority of patients reached 200/μL CD4⁺ and 1000/μL CD3⁺ cell counts between 3 and 6 months. The estimated 2-year overall survival was 66%; it was 64% for SCID patients and 65% for non-SCID patients and 63% for first HCT and 77% for salvage transplantations. Twenty-five patients died, most of them due to infection early after transplantation (before 100 days). In conclusion, haplo-PTCy is a feasible procedure, can cure two-thirds of children with PID, and can be used as rescue treatment for previous graft failure. © 2020 American Society for Transplantation and Cellular Therapy. Published by Elsevier Inc.

Latin American consensus on the supportive management of patients with severe combined immunodeficiency

Severe combined immunodeficiency (SCID) represents the most lethal form of primary immunodeficiency, with mortality rates of greater than 90% within the first year of life without treatment. Hematopoietic stem cell transplantation and gene therapy are the only curative treatments available, and the best-known prognostic factors for success are age at diagnosis, age at hematopoietic stem cell transplantation, and the comorbidities that develop in between. There are no evidence-based guidelines for standardized clinical care for patients with SCID during the time between diagnosis and definitive treatment, and we aim to generate a consensus management strategy on the supportive care of patients with SCID. First, we gathered available information about SCID diagnostic and therapeutic guidelines, then we developed a document including diagnostic and therapeutic interventions, and finally we submitted the interventions for expert consensus through a modified Delphi technique. Interventions are grouped in 10 topic domains, including 123 "agreed" and 38 "nonagreed" statements. This document intends to standardize supportive clinical care of patients with SCID from diagnosis to definitive treatment, reduce disease burden, and ultimately improve prognosis, particularly in countries where newborn screening for SCID is not universally available and delayed diagnosis is the rule. Our work intends to provide a tool not only for immunologists but also for primary care physicians and other specialists involved in the care of patients with SCID.

Does Pioglitazone Lead to Neutrophil Extracellular Traps Formation in Chronic Granulomatous Disease Patients?

Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase, the enzyme complex responsible for reactive oxygen species (ROS) production, is defective in chronic granulomatous disease (CGD) patients. This enzyme helps in antimicrobial host defense by phagocytes. CGD patients are unable to form neutrophil extracellular traps (NETs), which are composed of granule-derived proteins from neutrophils decorated with decondensed chromatin. Mitochondria have gained attention, being a rich source of flavochrome enzymes due to the presence of several sites for superoxide production. Recently, PPARγ agonists, a mitochondrial ROS inducer, induce mitochondrial ROS formation post-treatment in murine NADPH oxidase knockout models. Mitochondrial ROS is also essential for NOX-independent NETosis. Our study for the first time detects induction of NETosis independent of NADPH oxidase post-treatment with agonists such as pioglitazone and rosiglitazone in CGD subjects. Neutrophils isolated from CGD subjects were treated with pioglitazone and rosiglitazone. After treatment, qualitative analysis of NET formation was done using confocal microscopy after staining with DAPI. Quantitative estimation of extracellular DNA was performed using Sytox green. Mitochondrial ROS production with PPARγ agonist-treated/untreated neutrophils was detected using MitoSOX red. Pioglitazone and rosiglitazone induce significant NET formation in CGD patients. Our data clearly signify the effect of PPARγ agonists in induction of NET formation in CGD cases. Apart from the proposed experimental studies regarding the detailed mechanism of action, controlled trials could provide valuable information regarding the clinical use of pioglitazone in CGD patients as curative HSCT remains challenging in developing countries.