Pleuroparenchymal fibroelastosis: the prevalence of secondary forms in hematopoietic stem cell and lung transplantation recipients

Pleuroparenchymal fibroelastosis (PPFE) is a rare form of interstitial pneumonia, characterized by elastotic fibrosis involving the pleura and subpleural parenchyma, predominantly in the upper lobes. PPFE can be either idiopathic or secondary and mostly occurs as a late complication of lung or hematopoietic stem cell transplantation (HSCT). The aim of this study was to evaluate the prevalence of secondary forms in transplant recipients. An expert thoracic radiologist retrospectively reviewed high-resolution computed tomography exams of 700 HSCT recipients and 53 lung transplant recipients from the database of the Radiology Department of S. Orsola-Malpighi Hospital dating back from 2007. For each case that radiologically fulfilled PPFE criteria, the following details were retrieved: clinical characteristics, laboratory and functional data, pathologic findings (obtained from one patient) and metabolic data (obtained from three patients). Six cases clinically and radiologically consistent with PPFE were identified: two HSCT recipients (0.28%) and four lung transplant recipients (7.54%). In this study, PPFE was strongly associated with lung transplants as a late complication, with a prevalence of 7.54%.