Increased transient elastography-derived liver stiffness in fibrotic interstitial lung disease compared with healthy...

Fibrotic interstitial lung diseases are chronic diffuse parenchymal disorders characterised by progressive scarring and substantial morbidity. Transient elastography-derived liver stiffness is an established non-invasive marker of hepatic fibrosis, but it is unclear whether this liver-focused measurement carries any signal related to fibrotic interstitial lung disease. To assess, in a cross-sectional observational cohort, whether liver stiffness (LS) measured by transient elastography (TE) discriminates individuals with interstitial lung disease (ILD) from healthy controls and relates to HRCT-based disease burden, and to explore in-sample an empirical cut-point with pre-specified sensitivity analyses.

65 patients with ILD and 60 age- and sex-matched healthy controls underwent LS assessment using FibroScan^®. LS values were compared with clinical parameters, radiological scores (Warrick Score and Early Decision Severity Score [EDSS]), and functional indices. Receiver operating characteristic (ROC) analysis determined the optimal LS cut-off for ILD prediction. Subgroup analyses compared connective tissue disease-related ILD (CTD-ILD) to non-CTD-ILD, and correlations between LS and demographic or disease-specific variables were examined.

Median LS was significantly higher in ILD patients than in controls (4.90 vs. 2.98 kPa; p < 0.001). ROC analysis yielded an area under the curve of 0.867 for LS in predicting ILD, with a cut-off of 3.88 kPa (sensitivity, 76.9%; specificity, 85.0%). Non-CTD-ILD patients exhibited greater LS than CTD-ILD patients (6.5 vs. 4.6 kPa; p = 0.009). Within the CTD-ILD subgroup, only age correlated with LS (r = 0.402; p = 0.012). An LS ≥ 7.0 kPa was associated with a usual interstitial pneumonia pattern in 72.2% of cases, and advanced fibrosis (F3) was more frequent in non-CTD-ILD (p = 0.023).

In this cross-sectional cohort, TE-derived liver stiffness shows in-sample discriminatory ability and aligns with HRCT involvement, indicating a candidate biomarker signal; prognostic use is unproven and warrants adequately powered longitudinal validation.