ABSTRACT Bronchiolitis obliterans (BO) is a chronic obstructive lung disease affecting bronchioles and smaller airways, often secondary to infection, hematopoietic cell transplantation (HCT), or lung transplantation. Despite its associated morbidity and mortality post‐HCT, no standard treatment exists. This systematic review aimed to compare treatment outcomes for post‐HCT BO in children. Eligible studies were retrieved from PubMed, Scopus, and Web of Science using terms “bronchiolitis obliterans” and “hematopoietic stem cell transplantation,” including clinical trials, cohorts, cross‐sectional studies, case reports, and case series. We analyzed treatment response, pulmonary function improvement, and survival. No significant differences were observed in response between treatment categories ( p > 0.18); however, complex multidrug or cell‐based regimens showed the highest overall response (66%). Immunosuppressive regimens had the highest non‐response rate (42%), possibly due to treatment bias. FEV1 change was not statistically different ( p = 0.33), but FAM (corticosteroids, macrolide antibiotics, and leukotriene receptor antagonists)‐based and systemic steroid regimens showed numerically better improvement. Survival differed significantly between treatment groups ( p = 0.01), highest with FAM‐based and lowest with immunosuppressive regimens. These findings suggest clinical benefits from advanced or FAM‐based therapies, especially in milder cases. Further large‐scale studies are needed to confirm these results.
Kalantari et al. (2025) studied this question.