Data indicative of likely shared pathogenetic mechanisms between idiopathic pulmonary fibrosis (IPF) and other progressive fibrotic lung diseases; and subgroups of patients with diseases other than IPF with a progressive IPF-like fibrotic phenotype

Data indicative of IPF-like disease progresssion in subgroups of patients with other progressive fibrotic lung diseases
 IPF-like outcomes in CHP patients with a histological or CT pattern of UIP[46–51]
 IPF-like outcomes in RA patients with a histological or CT pattern indicative of UIP[51–54, 58–61]
 IPF-like outcomes in IPAF patients with a histological or CT pattern indiciative of UIP[63]
 Outcomes intermediate between IPF and other progressive fibrotic diseases in patients with unclassifiable ILD[65–67]
 Reports of patients with drug-induced lung disease exhibiting a fatal progressive fibrotic phenotype despite drug withdrawal[70]
 IPF-like outcomes in patients with idiopathic NSIP with disease progression at 6–12 months (as judged by serial FVC trends)[68, 69]
 Linkage between serial decline in FVC and mortality in CHP, SSc-ILD and rheumatoid lung, similar to that seen in IPF[59, 72, 73]
Data indicative of pathogenetic mechanisms common to IPF and other progressive fibrotic lung diseases
 Shared genetic predilection for IPF and rheumatoid lung[76]
 Similar links between short telomere lengths and mortality in IPF and CHP[77, 78]
 Linkage between alveolar epithelial cell dysfunction/injury and pulmonary function decline in IPF and SSc-ILD[79]
 Pathobiological mechanisms likely to contribute to disease progression in both IPF and SSc-ILD: alveolar stem cell exhaustion/cellular senescence, mitochondrial dysfunction, impaired autophagy, epigenetic modifications, and immune dysregulation[80–83]

CHP: chronic hypersensitivity pneumonitis; CT: computed tomography; UIP: usual interstitial pueumonia; RA: rheumatoid arthritis; IPAF: interstitial pneumonitis with autoimmune features; ILD: interstitial lung disease; NSIP: non-specific interstitial pneumonia; FVC: forced vital capacity; SSc: systemic sclerosis.