The 13C-caffeine breath test detects significant fibrosis in patients with nonalcoholic steatohepatitis

BACKGROUND: The C-caffeine breath test (CBT) is a noninvasive tool for the evaluation of the cytochrome P450 system, implicated in the development of nonalcoholic steatohepatitis. GOAL: To apply the CBT to assess the extent of hepatic fibrosis in patients with nonalcoholic fatty liver disease (NAFLD). METHODS: Twenty-six consecutive patients (mean age 56.1±6.85 y, 69.2% women) with NAFLD underwent the CBT, in addition to the clinical and laboratory evaluations and liver biopsy. Ten healthy individuals matched for age served as controls. RESULTS: Mean delta over baseline values differed significantly between patients and controls (1.51±0.9 vs. 2.37±0.8 Δ‰/mg, respectively) (P=0.01) and were significantly higher in patients with fibrosis stage <2 (Brun's system) (2.0±0.77 vs. 1.3±0.9 for stage ≥2, P=0.05). Mean delta over baseline values correlated highly with fibrosis stage (P=0.01), albumin (P=0.007), international normalized ratio (P=0.04), bilirubin (P=0.0008), and platelet count (P=0.0001). On multivariate stepwise logistic regression analysis, CBT was the best predictor of severe fibrosis (stage ≥2) (odds ratio 0.274, 95% confidence interval 0.086-0.872, P=0.028), with an area under the curve of 0.788. CONCLUSIONS: The CBT is safe and easy to perform. It can reliably predict severe hepatic fibrosis in patients with NAFLD. Further large-scale studies are still needed.