BACKGROUND: Bronchiolitis obliterans syndrome (BOS) is a late onset noninfectious pulmonary complication of allogeneic hematopoietic cell transplantation (HCT) that is often diagnosed in advanced stage with severe lung impairment. Increasing utilization of HCT for the treatment of hematologic diseases worldwide translates to an increasing burden of BOS, particularly for the community pulmonologist. Early recognition of BOS, which offers the best opportunity to mitigate morbidity and mortality, is hampered by incomplete knowledge of the clinical course and disease process. The goal of this research statement is to survey our current understanding of BOS and to define the research agenda for the early detection of BOS.

METHODS: We convened a multidisciplinary panel that included community representatives for an in-depth survey of the published literature followed by an online workshop.

RESULTS: Major knowledge gaps were identified within interrelated themes of natural history and pathogenesis, risk factors, and the clinical diagnostic approach.

CONCLUSIONS: This statement reflects the detailed assessment of identified knowledge gaps with associated key research questions, as well as a proposed research roadmap to stimulate cross-disciplinary collaborations from pre-clinical to clinical investigations.