How I Treat: Transplantation for primary immune regulatory diseases and inflammatory disorders

Primary immune regulatory disorders (PIRDs), autoinflammatory, and hyperinflammatory syndromes can be life-threatening and/or significantly impact quality of life. Targeted immune modulation may control symptoms for some, but allogeneic hematopoietic stem cell transplantation (alloHCT) remains the only cure for many patients. Despite advances in alloHCT, outcomes for this population continue to need optimization. Focus areas include referral timing, patient selection, multidisciplinary evaluation, targeted pretransplant immune suppression (PTIS), graft selection, model- and exposure-based conditioning, and post-alloHCT management. Here, we describe our preferred alloHCT approach for this patient population. This includes early alloHCT referral, continued evaluation to identify an appropriate alloHCT window, 6–12 wk of targeted PTIS for inflamed patients, a myeloablative model-based reduced-toxicity conditioning regimen, a strong index of suspicion for posttransplant immune dysregulation, and multidisciplinary long-term follow-up. Emphasis is placed on the need for predictive biomarkers to guide clinical decision-making, objective measurements of long-term response/disease resolution, and prospective multicenter trials. By refining our approaches, curative outcomes will continue to improve.