Breath Test Predicts Outcomes in Chronic Liver Disease Patients

A methacetin breath test (MBT) was assessed for predicting survival in patients with chronic liver disease. In healthy hepatocytes, methacetin is rapidly and exclusively metabolized and CO2 is produced. This reflects the hepatic microsomal function of cytochrome P450 1A2 (CYP1A2).

Five hundred and seventy-five patients with chronic liver disease of diverse etiologies participated in a study evaluating the MBT; this included 384 from the Hadassah Medical Center (Jerusalem, Israel) and 191 from the University Hospital Zurich (Zurich, Switzerland).

Fasting patients were given a solution of 13C methacetin to drink. After a waiting period during which the patients sat and breathed normally, a nasal cannula measured exhaled carbon dioxide tagged with 13C for 15 minutes. The rate and magnitude of change in 13C/12C ratio in the exhaled breath correlated to the presence and severity of liver disease. The device used for the breath test, Breath ID, was developed by Exalenz Bioscience Ltd (Modiin, Israel).

The 13C-MBT provided a rapid, noninvasive assessment of liver impairment in patients with chronic liver disease. 13C-MBT accurately predicted survival for up to 2 years, and may serve as a powerful tool for determining prognosis in this patient population. 13C-MBT may be able to predict survival within the specific Model for End-Stage Liver Disease (MELD) scores.

Patients with chronic liver disease have variable rates of disease progression. Determining hepatic reserve is essential for assessing prognosis and organ allocation. Current tools including liver enzymes, synthetic function tests, imaging, and liver biopsy lack the ability to accurately assess hepatic impairment.

The study was performed by Gadi Lalazar M.D. and a team from the Liver Unit, Department of Internal Medicine, Hadassah Hebrew University Medical Center, and colleagues in Israel and Switzerland. It was presented by Dr. Lalazar at the Digestive Disease Week (DDW), which took place in Chicago (USA) on May 30-June 4, 2009.

Dr Lalazar said that the MBT could be used to assess prognosis from the earliest stages of liver disease to cirrhosis, to help doctors determine whether a cirrhotic patient has sufficient liver reserve to undergo a surgical procedure, to prioritize patients for liver transplantation, and to decide when patients need to start therapy for chronic viral hepatitis. To date validation studies have been conducted on its utility for the detection of fibrosis, Helicobacter pylori, and its correlation with the traditional mass-spectrometry method. However, there remains a need to validate the MBT for the assessment of prognosis in a new cohort of patients.

Related Links:
Hadassah Medical Center
University Hospital Zurich
Exalenz Bioscience Ltd