In a new study, researchers characterized outcomes for adolescents and adults with inborn errors of immunity (IEI) treated with hematopoietic stem cell transplantation (HSCT), as well as factors possibly related to outcomes with this treatment. The study results were reported in the journal Blood.
Encouraging outcomes have been seen with HSCT in children with IEI, but this approach has not yet been used as often with older (adolescent) pediatric patients and adults. “This important, timely study reports detailed outcomes following HSCT for the largest cohort to date of IEI patients aged 15 years or more at transplant,” the researchers wrote in their report.
The study was an international, multicenter, retrospective analysis of data from the European Society for Blood and Marrow Transplantation registry. It included patients aged 15 years or older at the time of HSCT who had received a clinical or genetic diagnosis of IEI, and for whom HSCT was initially performed between the years of 2000 and 2019. A variety of patient demographic and clinical data were analyzed in the study. Overall survival (OS) and event-free survival (EFS) were the primary study end points, and possible risk factors related to outcomes were also examined.
The study included a total of 329 patients with IEI treated with HSCT. Patients had a median age of 18.4 years at HSCT, with ages ranging from 15 years to 62.5 years at the time of the procedure. The median time from clinical diagnosis to HSCT was 63.1 months (interquartile range, 13-189.1).
During the time of HSCT, 33% of patients did not have any active IEI-related complications, while 1 complication was present in 36.3% of patients, and 2 or more were present in 30.8%. Possible complications included bronchiectasis, colitis, malignancy, hepatic comorbidity, splenectomy, and granulomatous lymphocytic inflammatory lung disease.
The study had a median follow-up of 44.3 months after HSCT. The OS rate at 1 year after HSCT was estimated to be 78%, with the 5-year OS rate estimated to be 71%. The 1-year EFS rate after HSCT was estimated to be 65%, and the 5-year EFS rate was estimated to be 62%. Grade 3 or 4 acute graft vs host disease (GVHD) was reported in 8% of patients, and extensive chronic GVHD occurred with a cumulative incidence of 7%.
Univariate analyses showed OS and EFS to be worse in patients who had a primary antibody deficiency, bronchiectasis, prior splenectomy, liver dysfunction, or a higher number of IEI-associated complications. A higher pretransplant score on the hematopoietic cell transplant comorbidity index (HCT-CI), and a transplant performed before 2014, also appeared to be associated with worse OS. In a multivariable analysis, the presence of a greater number of IEI-related complications showed a possible trend related to worse EFS (P =.05).
“In conclusion, we report the largest cohort of older adolescents and adults with IEI having undergone HSCT and have identified IEI subgroup, HCT-CI score, and the cumulative number of IEI-related comorbidities as risk factors for adverse outcome,” the study investigators wrote in their report.
Disclosures: Some authors have declared affiliations with or received grant support from the pharmaceutical industry. Please refer to the original study for a full list of disclosures.
Albert MH, Sirait T, Eikema DJ, et al; for the Inborn Errors Working Party (IEWP) of the European Society for Blood and Marrow Transplantation (EBMT) and the European Society for Immunodeficiencies (ESID). Hematopoietic stem cell transplantation for adolescents and adults with inborn errors of immunity: an EBMT IEWP study. Blood. 2022;140(14):1635-1649. doi:10.1182/blood.2022015506