Significance of the 13C-caffeine breath test for patients with cirrhosis

BACKGROUND The 13C-caffeine breath test (CBT) is a non-invasive, quantitative test of liver function which has been shown to correlate inversely to the Child-Pugh score. The aim of the study was to determine the utility of CBT in the assessment of cirrhosis and its correlation to the model for end-stage liver disease (MELD) score. METHODS Thirty-nine patients, 29 with cirrhosis and 10 with chronic liver disease without cirrhosis, and 8 healthy volunteers were included. Cirrhotic patients were graded according to Child-Pugh and MELD scores. All participants underwent CBT and laboratory tests on the same day. The results of the CBT were expressed as percentages of changes over baseline values (Δ‰) per 100 mg caffeine. RESULTS The mean single 15-min, 30-min, 45-min and 1-h CBT results, as well as cumulative CBT values differed significantly between healthy controls or chronic liver disease patients and cirrhotics (1-h CBT: 3.22±1.06 or 3.56±2.80 vs. 1.69±2.52, P≤0.01). In contrast, the CBT results at any time point or cumulative values did not correlate with MELD or Child-Pugh scores. Receiver operating characteristics (ROC) analysis showed that the 30-min CBT values were more accurate in differentiating cirrhotics from chronic liver disease patients (area under ROC curve: 0.871). CONCLUSIONS CBT can reliably differentiate the patients with decompensated cirrhosis from non-cirrhotic patients with chronic liver diseases. However, in patients with decompensated cirrhosis, CBT results do not seem to be associated with the Child-Pugh and MELD scores.