Abstract
Non-idiopathic pleuroparenchymal fibroelastosis (PPFE) has been increasingly reported in the literature. Little is known about the clinical relevance of PFFE and hypersensitivity pneumonitis (HP) overlap; therefore, we sought to investigate the clinical, radiological, and pathological features of patients with these two diseases. Five patients were identified, and the detailed characterization of these cases revealed a heterogeneous group in terms of clinical and treatment options. No mortality, acute exacerbations, or a significant decline in lung function were verified. Our cases seem to have a more “benign” disease behavior, contrary to previous idiopathic PPFE studies. More studies are needed to corroborate these findings and to better elucidate the clinical significance of PPFE and HP overlap.