Measurement of hepatic functional mass by means of 13C-methacetin and 13C-phenylalanine breath tests in chronic liver disease: comparison with Child-Pugh score and serum bile acid levels.

AIM: To evaluate and compare the clinical usefulness of 13C-phenylalanine and 13C-methacetin breath tests in quantitating functional hepatic mass in patients with chronic liver disease and to further compare these results with those of conventional tests, Child-Pugh score and serum bile acid levels. METHODS: One hundred and forty patients (50 HCV-related chronic hepatitis, 90 liver cirrhosis patients) and 40 matched healthy controls were studied. Both breath test and routine liver test, serum levels of cholic and chenodeoxycholic acid conjugates were evaluated. RESULTS: Methacetin breath test, expressed as 60 min cumulative percent of oxidation, discriminated the hepatic functional capacity not only between controls and liver disease patients, but also between different categories of chronic liver disease patients. Methacetin breath test was correlated with liver function tests and serum bile acids. Furthermore, methacetin breath test, as well as serum bile acids, were highly predictive of Child-Pugh scores. The diagnostic power of phenylalanine breath test was always less than that of methacetin breath test. CONCLUSION: Methacetin breath test represents a safe and accurate diagnostic tool in the evaluation of hepatic functional mass in chronic liver disease patients.

13C-methacetin breath test for monitoring hepatic function in cirrhotic patients before and after liver transplantation.

BACKGROUND: In patients with chronic liver disease, the measurement of liver function is critical for monitoring disease progression, predicting the prognosis and choosing therapeutic strategies. The 13C-methacetin breath test is a simple, non-invasive diagnostic tool based on an inexpensive, non-toxic substance, which allows the accurate measurement of liver functional reserve. AIM: To investigate the 13C-methacetin breath test as a tool to monitor hepatic function in liver transplant candidates and recipients. METHODS: Twenty-eight cirrhotic patients listed for orthotopic liver transplantation and 10 healthy controls were studied. The 13C-methacetin breath test (75 mg per os) was performed at baseline and at 12-week intervals. Intra-operative measurements were obtained during the liver transplantation procedure in nine patients. Results were expressed as the 13C-methacetin cumulative oxidation percentage 45 min after substrate ingestion. RESULTS: The mean 13C-methacetin cumulative oxidation at 45 min was 16.4 +/- 3.5% in healthy controls and 5.4 +/- 4.2% in cirrhotic patients at the time of listing. In 11 patients who underwent successful liver transplantation, mean oxidation increased from 3.3 +/- 1.6% before transplantation to 17.0 +/- 5.2% at 6 months of follow-up. Variations in methacetine oxidation were closely related to the recovery of liver function. The mean intra-operative 13C-methacetin cumulative oxidation increased from 0.1% during the anhepatic phase to 3.7 +/- 2.0% 2 h after reperfusion. CONCLUSIONS: The 13C-methacetin breath test is a simple and potentially useful tool for monitoring hepatic function in cirrhotic patients listed for liver transplantation, and during the intra-operative and post-operative phases.