Pleuroparenchymal Fibroelastosis: A Review with a Focus on a Non-Infectious Complications after Hematopoietic Stem Cell Transplant

Pleuroparenchymal fibroelastosis (PPFE) is a rare disease that is currently classified as an idiopathic interstitial pneumonia. Although originally described as an idiopathic disease, PPFE has now been identified as a rare complication following hematopoietic stem cell transplant (HSCT). Unlike other pulmonary complications after HSCT, PPFE occurs very late after transplant. Etiologies for PPFE after HSCT remain to be fully established. Infections and adverse effects to alkylating chemotherapy have been suggested as possible causes. In several cases, there is an association of PPFE with bronchiolitis obliterans syndrome after HSCT, suggesting that PPFE may be another manifestation of pulmonary chronic graft versus host disease after HSCT. Algorithms have been designed to assist in confirming a diagnosis of PPFE without the need for a surgical lung biopsy, however at present, no biomarker is established for the diagnosis or to predict the progression of disease. Presently, there is no current therapy for PPFE, but fortunately the disease progresses slowly in most patients.