Progressive pulmonary fibrosis associated autoimmune diseases: Systematic review of the literature

Introduction: Connective tissue disease-related interstitial lung disease (CTD-ILD) accounts for 30% of all cases of ILD. Some patients progress and develop progressive pulmonary fibrosis, which has a prognosis comparable to interstitial pulmonary fibrosis. In this study, relevant evidence about epidemiology, risk factors, biomarkers, and treatment are reviewed. Materials and methods: A systematic review of the literature was carried out. Original observational and descriptive articles were included. Articles not providing information about the CTD diagnosis were excluded. PUBMED, EMBASE, SCOPUS, and LILACS were all searched. The total number of articles obtained was 528; data were extracted from 61 original articles. Results: On average, ILD in these patients progressed by 33.7% over time. Patients with progressive pulmonary fibrosis had a similar 3.7-year median survival as those with idiopathic pulmonary fibrosis. Mortality was markedly increased (hazards ratio 3.29; 95% CI 2.76–3.82). A progressive course was seen in 34% of scleroderma (SSc) related ILD cases. Six interferon-induced proteins and a proteomic profile of 12 biomarkers were used to predict progression and response to treatment. The INBUILD and SENSCIS studies that assessed the effectiveness of nintedanib effectiveness revealed a reduced decrease in forced vital capacity. Progression in rheumatoid arthritis (RA) related ILD ranges from 38% to 50%. Control of RA disease activity and use of antifibrotics benefit the lungs. Conclusion: A significant proportion of patients with CTD-ILD have progressive lung disease, with the corresponding adverse mortality effects. The majority of the data regarding CTD-ILD are from cohorts of patients with RA-ILD and SSc-ILD, in which antifibrotics and concurrent immunosuppressive treatments have been effective. There is not enough information available on other autoimmune disorders to draw any firm conclusions regarding progression rates or treatment effects.