Subclinical liver fibrosis in patients with idiopathic pulmonary fibrosis

Data on the presence of subclinical fibrosis across multiple organs in patients with idiopathic lung fibrosis (IPF) are lacking. Our study aimed at investigating through hepatic transient elastography (HTE) the prevalence and clinical impact of subclinical liver fibrosis in a cohort of patients with IPF. Patients referred to the Centre for Rare Lung Disease of the University Hospital of Modena (Italy) from March 2012 to February 2013 with established diagnosis of IPF and without a documented history of liver diseases were consecutively enrolled and underwent HTE. Based on hepatic stiffness status as assessed through METAVIR score patients were categorized as “with liver fibrosis” (corresponding to a METAVIR score of F1–F4) and “without liver fibrosis” (METAVIR F0). Potential predictors of liver fibrosis were investigated through logistic regression model among clinical and serological variables. The overall survival (OS) was assessed according to liver fibrosis and multivariate Cox regression analysis was used to identify independent predictors. In 13 out of 37 patients (35%) with IPF, a certain degree of liver fibrosis was documented. No correlation was found between liver stiffness and clinical–functional parameters. OS was lower in patients ‘with liver fibrosis’ than in patients ‘without liver fibrosis’ (median months 33 [23–55] vs. 63 [26–94], p = 0.038). Patients ‘with liver fibrosis’ presented a higher risk of death at seven years as compared to patients ‘without liver fibrosis’ (HR = 2.6, 95% CI [1.003–6.7], p = 0.049). Higher level of AST to platelet ratio index (APRI) was an independent predictor of survival (HR = 4.52 95% CI [1.3–15.6], p = 0.02). In our cohort, more than one-third of IPF patients had concomitant subclinical liver fibrosis that negatively affected OS. These preliminary claims further investigation aimed at clarifying the mechanisms beyond multiorgan fibrosis and its clinical implication in patients with IPF.