Non-invasive evaluation of steatosis and fibrosis in the liver in adults patients living with cystic fibrosis.

Abstract

Background & aims: Cystic fibrosis hepatobiliary involvement is a heterogeneous and systemic entity. The primary objective was to determine the prevalence of steatosis, by magnetic resonance-proton density fat fraction (MR-PDFF), and liver fibrosis, by magnetic resonance elastography (MRE), in a cohort of adults with cystic fibrosis. The secondary objective was to determine the diagnostic yield of widely available non-invasive liver markers for steatosis and fibrosis, and vibration controlled transitional elastography (VCTE) releasing Control Attenuation Parameter (CAP) (dB/m) and stiffness (kPa), with the aim of proposing a diagnostic algorithm.

Methods: We conducted a cross-sectional study including 101 adult patients with cystic fibrosis seen in a multidisciplinary unit. The study encompassed a clinical evaluation, morpho-functional assessment, VCTE, non-invasive liver markers and MR-PDFF and MRE. Diagnostic accuracy was assessed using ROC curves and 2 × 2 tables.

Results: MR-PDFF detected hepatic steatosis in 18 of 101 (17.8 %) patients, while MRE detected significant liver fibrosis in 15 of 101 (14.9 %). The VCTE cut-off with the best diagnostic yield, determined by the Youden index, was 222 dB/m for the presence of steatosis (AUC 0.864 (95 % CI 0.768-0.961; p < 0.001) and the VCTE cut-off was 6.65 kPa for liver fibrosis (AUC 0.951(95 % CI 0.81-1; p = 0.053). A screening algorithm for hepatic steatosis was developed using the fatty liver index (FLI) and CAP, with a negative predictive value of 83.3 %. For liver fibrosis, it was outperformed by the Hepamet Fibrosis Score (HFS) and VCTE, with a negative predictive value of 100 %.

Conclusions: The prevalence of hepatic steatosis and liver fibrosis was 17.8 % and 14.9 %, respectively. VCTE alone or in combination with FLI for steatosis or HFS for fibrosis demonstrated high diagnostic accuracy. This approach effectively allows for the exclusion of steatosis and fibrosis, thereby reducing the need for MR-PDFF and MRE studies.