Noninvasive elastography-based assessment of liver fibrosis progression and prognosis in primary biliary cirrhosis

Abstract

The development of liver fibrosis markers in primary biliary cirrhosis (PBC) is needed to facilitate the assessment of its progression and the effectiveness of new therapies. Here, we investigated the potential usefulness of transient elastography (TE) in the noninvasive evaluation of liver fibrosis stage and disease progression in PBC. We performed, first, a prospective performance analysis of TE for the diagnosis of METAVIR fibrosis stages in a diagnostic cohort of 103 patients and, second, a retrospective longitudinal analysis of repeated examinations in a monitoring cohort of 150 patients followed-up for up to 5 years. All patients were treated with ursodeoxycholic acid. Diagnostic thresholds of liver stiffness in discriminating fibrosis stages ≥ F1, ≥ F2, ≥ F3, and =F4 were 7.1, 8.8, 10.7, and 16.9 kPa, respectively. TE showed high performance and was significantly superior to biochemical markers (e.g., aspartate aminotransferase [AST]/platelet ratio, FIB-4, hyaluronic acid, AST/alanine aminotransferase ratio, and Mayo score) in diagnosing significant fibrosis, severe fibrosis, or cirrhosis. Analysis of the monitoring cohort data set using generalized linear models showed the following: (1) an overall progression rate of 0.48 ± 0.21 kPa/year (P = 0.02) and (2) no significant progression in patients with F0-F1, F2, or F3 stages, but a significant increase (4.06 ± 0.72 kPa/year; P < 0.0001) in cirrhotic patients. A cut-off value of 2.1 kPa/year was associated with an 8.4-fold increased risk of liver decompensations, liver transplantations, or deaths (P < 0.0001, Cox regression analysis). TE is one of the best current surrogate markers of liver fibrosis in PBC. Over a 5-year period, on-treatment liver stiffness appears stable in most noncirrhotic PBC patients, whereas it significantly increases in patients with cirrhosis. Progression of liver stiffness in PBC is predictive of poor outcome.