Periostin Defines a Pathological Fibroblast Program Enriched in Restrictive Allograft Syndrome

Chronic lung allograft dysfunction (CLAD) is the major limitation to long-term survival after lung transplantation and includes distinct clinical phenotypes such as bronchiolitis obliterans syndrome (BOS) and restrictive allograft syndrome (RAS). To define fibroblast states associated with CLAD phenotypes, we performed single-cell RNA sequencing of dissociated human lung tissue obtained from explanted lung allografts. Integrated analysis identified a periostin (POSTN)-associated pathological fibroblast program enriched in RAS compared with BOS and control lungs.