For newborns and children with multiple inborn errors of immunity (IEI), allogeneic hematopoietic stem cell transplantation (HSCT) is the gold standard curative treatment; nevertheless, adolescents and adults with IEI were seldom recommended for transplant. The acceptance of HSCT for IEI patients presenting or developing major organ damage later in life has been hindered by a lack of published HSCT outcome data outside limited, single-center trials and perceived high risk of transplant-related death. 

A total of 329 IEI patients were included in the extensive retrospective, multicenter HSCT outcome analysis (age range, 15-62.5 years at HSCT). Between 2000 and 2019, patients underwent their first HSCT. Overall survival (OS) and event-free survival (EFS) were the primary goals. Infections, bronchiectasis, colitis, cancer, inflammatory lung disease, splenectomy, hepatic dysfunction, and systemic immunosuppression were among the risk variables researchers examined for IEI-subgroup & IEI-specific HSCT. 

With a median follow-up of 44.3 months, there were low incidences of severe acute (8%) or extensive chronic (7%) graft-versus-host disease, and the projected overall survival (OS) at 1 and 5 years after HSCT for all patients was 78% and 71%, respectively and EFS was 65% and 62%, respectively. Patients with primary antibody deficiency, bronchiectasis, previous splenectomy, hepatic comorbidity, and higher hematopoietic cell transplant comorbidity index scores had worse OS and EFS on univariate analysis. According to a multivariate analysis, EFS was worse in people who had more IEI-related problems. OS and EFS were not significantly impacted by donors or age. 

They had discovered age-independent risk indicators for unfavorable outcomes, giving desperately needed proof as to which individuals would benefit from HSCT the most.