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Updated: Jun 20, 2026
Imaging Features of Systemic Sclerosis-Associated Interstitial Lung Disease
Published on: June 16, 2020
Spectrum of autoantibodies and other serological parameters in connective tissue disease-associated interstitial lung
Pooja Jaiswal1, Tanya Athavale2, Amita Athavale2
1Department of Clinical & Experimental Immunology, Indian Council of Medical Research, National Institute of Immunohaematology, Mumbai, India.
Background:
Connective tissue disease-associated interstitial lung disease (CTD-ILD) is a major cause of morbidity and mortality in autoimmune disorders, yet detailed serological characterization remains limited in Indian cohorts.
Objective:
This study aimed to evaluate and compare demographic, radiological, autoantibody, and serum profiles between CTD-ILD and non-CTD-ILD patients from Western India and to delineate hospitalization patterns and mortality outcomes among CTD-ILD patients.
Methods:
This single-centre, cross-sectional study enrolled 200 patients with ILD (n = 90 with CTD-ILD and n = 110 with non-CTD-ILD) from a tertiary care centre who were evaluated on a clinico-radiological basis. Antinuclear antibodies and ANA subspecificities were assessed using indirect immunofluorescence and a line blot assay. Serological parameters were quantified using ELISA and multiplex bead-based assays.
Results:
CTD-ILD patients were significantly younger (49 vs. 57 years; p < 0.001) and predominantly female (80.0% vs. 59.1%; p = 0.002). NSIP predominated in CTD-ILD (51.1%), whereas UIP predominated in non-CTD-ILD (46.4%; p < 0.001). On multivariable analysis, younger age (aOR = 0.954; p < 0.001), female sex (aOR = 2.709; p = 0.023), NSIP (aOR = 6.155; p = 0.001), and UIP (aOR = 8.877; p < 0.001) were independent predictors of CTD-ILD. ANA positivity was higher in CTD-ILD (70.0% vs. 54.5%; p = 0.025), with a predominance of high-titre ANA (81.0%, ≥1:160) and a speckled IFA pattern. The nucleolar pattern was significantly more prevalent in the CTD-ILD group (11.1%; p = 0.010). Disease-specific autoantibody enrichment was observed as follows: anti-SSA/Ro and AMA-M2 in RA-ILD, anti-RNP/Sm in MCTD-ILD, and anti-Scl-70 in SSc-ILD. Anti-MDA5 (p = 0.001), LDH (p = 0.019), and pro-inflammatory cytokines TNF-α, IFN-γ, IL-4, and IL-22 were significantly elevated in CTD-ILD, whereas MMP7 levels were lower (p = 0.025). TNF-α, IL-22, and IL-4 remained independent predictors in the multivariable analysis. Among CTD-ILD patients, 20.0% required hospitalization, with significantly higher in-hospital mortality in admitted patients (27.8% vs. 4.2%; p = 0.007) than in non-admitted CTD-ILD patients.
Conclusion:
CTD-ILD patients demonstrated distinct demographic, radiological, autoantibody, and serological profiles compared to non-CTD-ILD patients, characterized by elevated anti-MDA5, LDH, and pro-inflammatory cytokines alongside lower MMP7 levels, reflecting an immune-driven rather than fibrosis-dominant pathobiology. These findings contribute to bridging the knowledge gap in the serological characterization of CTD-ILD in Indian cohorts.
