Interstitial pneumonia with autoimmune features show better survival and less exacerbations compared to idiopathic pulmonary fibrosis

• Published in: BMC pulmonary medicine Vol. 19; no. 1; p. 120
• Main Authors: Lim, Jeong Uk, Gil, Bo Mi, Kang, Hye Seon, Oh, Jongyeol, Kim, Yong Hyun, Kwon, Soon Seog
• Format: Journal Article
• Language: English
• Published: England BioMed Central Ltd 04-07-2019; BioMed Central; BMC
• Subjects: Aged; Aged, 80 and over; Autoimmunity; Comparative analysis; Connective tissue disease; Connective Tissue Diseases - complications; Connective Tissue Diseases - immunology; Databases, Factual; Female; Fibrosis; Humans; Idiopathic pulmonary fibrosis; Idiopathic Pulmonary Fibrosis - mortality; Incidence; Interstitial lung disease; Interstitial pneumonia with autoimmune features; Lung diseases; Lung Diseases, Interstitial - etiology; Lung Diseases, Interstitial - mortality; Male; Middle Aged; Mortality; Multivariate Analysis; Physiological aspects; Pneumonia; Prognosis; Prospective Studies; Pulmonary fibrosis; Republic of Korea - epidemiology; Respiratory tract diseases; Survival Analysis; Tomography, X-Ray Computed; Republic of Korea; South Korea; Connective tissue disease; Interstitial lung disease; Interstitial pneumonia with autoimmune features; Idiopathic pulmonary fibrosis
• ISSN: 1471-2466; 1471-2466
• DOI: 10.1186/s12890-019-0868-9

Patients with interstitial lung disease (ILD) who show features related to autoimmunity without meeting criteria for a defined connective tissue disease are categorized as interstitial pneumonia with autoimmune features (IPAF). The present study compared clinical characteristics and clinical outcomes of patients with IPAF to patients with connective tissue disease related-interstitial lung disease (CTD-ILD) and patients with idiopathic pulmonary fibrosis (IPF).
ILD patients who were consecutively enrolled in a single institution ILD cohort between 2008 and 2015 were evaluated for the study. Clinical data had been prospectively collected, while radiologic imaging and pathologic findings were re-reviewed for the present study.
Out of 305 patients with ILD, 54 (17.7%) patients met the classification of IPAF, 175 (57.4%) patients had IPF, and 76 (24.9%) patients were diagnosed with CTD-ILD. Compared to IPF, incidences of acute exacerbations in 1,3 and 5 years were significantly less in the IPAF group (p = 0.022, p = 0.026 and p = 0.007, respectively). From multivariate analysis for mortality, age (p = 0.034, HR 1.022, 95% CI: 1.002-1.044), FVC (p < 0.001, HR 0.970, 95% CI: 0.955-0.984), ILD exacerbation (p = 0.001, HR 2.074, 95% CI: 1.366-3.148), and ILD type (p = 0.047, HR 0.436, 95% CI: 0.192-0.984 (IPAF vs IPF), respectively) showed significant association.
Compared to the other ILD groups, IPAF showed distinct clinical characteristics. The IPAF group showed better survival and less episodes of exacerbation when compared to the IPF group.