Progressive fibrosing interstitial lung disease which means idiopathic pulmonary fibrosis plus progressive pulmonary fibrosis

Idiopathic pulmonary fibrosis (IPF) is a disease of unknown etiology characterized by chronic progressive fibrosing interstitial lung disease. In 2017, the INBUILD study introduced the concept of progressive fibrosing interstitial lung disease (PF-ILD) and confirmed the efficacy of nintedanib for its treatment. In 2022, the ATS/ERS/JRS/ALAT guidelines established the concept of progressive pulmonary fibrosis (PPF) along with a standardized diagnostic criterion for non-IPF forms of progressive fibrosing interstitial lung disease. PPF serves as a collective term for chronic progressive fibrosing interstitial lung diseases that exclude IPF, with disease progression similar to that of IPF and a poor prognosis. Although some scholars propose that PPF can replace the preceding concept of PF-ILD, the author contends that PPF cannot substitute for PF-ILD, and the term "PF-ILD" should remain in use. The integration of IPF and PPF can be considered equivalent to PF-ILD and can be succinctly expressed as: PF-ILD=IPF+PPF.