Non-invasive estimation of liver fibrosis in non-alcoholic fatty liver disease using the 13 C-caffeine breath test.

摘要

BACKGROUND AND AIM: Fibrotic progression in non-alcoholic fatty liver disease (NAFLD) is associated with impaired hepatic function. The (13) C-caffeine breath test (CBT) is a non-invasive, quantitative test of liver function. We sought to determine the utility of the CBT in detecting hepatic fibrosis in NAFLD. METHODS: The CBT was applied to 48 patients with NAFLD. CBT results were compared to clinical, biochemical and histological data. Twenty-four healthy subjects served as controls. RESULTS: Patients with simple steatosis had similar CBT values (2.28 +/- 0.71 Delta per thousand per 100 mg caffeine) to controls (2.31 +/- 0.85, P = 1.0). However, CBT was significantly reduced in patients with non-alcoholic steatohepatitis (1.59 +/- 0.65, P = 0.005) and cirrhosis (1.00 +/- 0.73, P < 0.001). CBT significantly correlated with Brunt's fibrosis score (r = -0.49, P < 0.001) but not with steatosis (P = 0.23) or inflammation (P = 0.08). CBT also correlated with international normalized ratio (r = -0.61, P < 0.001), albumin (r = 0.37, P = 0.009), aspartate aminotransferase/alanine aminotransferase (r = -0.34, P = 0.018) and platelets (r = 0.31, P = 0.03). On multivariate analysis, age (odds ratio 1.12, 95% confidence interval 1.042-1.203, P = 0.002) and CBT (OR 0.264, 95% CI 0.084-0.822, P = 0.02) were independent predictors of significant fibrosis (F >/= 2). CBT yielded an area under the receiver operating characteristic curve of 0.86 for the diagnosis of cirrhosis. CONCLUSIONS: The CBT reflects the extent of hepatic fibrosis in NAFLD and represents a non-invasive predictor of fibrosis severity in this condition.