Hematopoietic stem cell transplantation for DOCK8 deficiency: durable immune reconstitution and long-term survival in 47 patients.

BACKGROUND: DOCK8 deficiency is a severe autosomal recessive combined immunodeficiency characterized by recurrent infections, severe atopy, immune dysregulation, and an increased risk of malignancy. Allogeneic hematopoietic stem cell transplantation (HSCT) remains the only curative treatment. We aimed to evaluate the long-term survival, immune reconstitution, and clinical outcomes of patients with DOCK8 deficiency following HSCT. METHODS: We conducted a retrospective single-center study of 47 patients with genetically confirmed DOCK8 deficiency who underwent HSCT at King Faisal Specialist Hospital and Research Centre between 2012 and 2025. Clinical, immunologic, genetic, transplant-related, and survival outcomes were analyzed. RESULTS: Eczema was present in all patients, while 91.5% had food allergies and 55% had recurrent sinopulmonary infections. Pre-transplant malignancy was identified in 17% of patients. Genetic analysis revealed predominantly homozygous loss-of-function variants. HSCT was performed at a median age of 6 years, using matched related donors in 37/47 patients (79%), matched unrelated donors in 7/47 (15%), haploidentical donors in 2/47 (4%), and an umbilical cord blood graft in 1/47 (2%). After a median follow-up of 7 years, overall survival and event-free survival were both 91.5%. Survival was 94.6% following matched related donor transplantation and 100% following matched unrelated donor transplantation. Mortality was limited to the early post-transplant period and was primarily associated with pre-existing malignancy or irreversible organ damage. All survivors demonstrated complete resolution of eczema and recurrent infections and robust immune reconstitution. CONCLUSIONS: HSCT provides excellent long-term survival and durable immune correction in patients with DOCK8 deficiency. Early diagnosis and transplantation before the development of irreversible organ damage are critical determinants of favorable outcomes.