Methacetin Breath Test Predicts Survival in Patients with Viral Hepatitis

The breath test, which has the trade name Breath ID, is based on the fact that methacetin is metabolized in the liver to produce acetaminophen and carbon dioxide. The test measures exhaled carbon dioxide following an oral dose of isotopically labeled methacetin. The speed of that reaction declines with impaired hepatic function

Gadi Lalazar M.D. and a team from the Liver Unit from the Department of internal medicine at Hadassah Hebrew University Medical Center (Jerusalem, Israel) and colleagues reported that the MBT accurately predicted survival of 395 patients with chronic viral hepatitis during a median of five months of follow-up. These patients had a higher Model for End-Stage Liver Disease (MELD) score and, therefore were at increased risk. The scientists concluded that MBT might increase physicians' ability to identify at-risk patients and allow those patients to be listed for liver transplantation earlier than using MELD alone to determine mortality risk.


MELD is a scoring system adopted by the United Network for Organ Sharing (Richmond, VI, USA) to assess liver disease severity and determine 3-month mortality. Viral hepatitis progresses at an unpredictable rate and the addition of another way of assessing disease progression could serve as an important adjunct to MELD. The basis for allocating liver transplants, MELD is known to be an imperfect predictor of survival, explained Dr. Lalazar.

"The breath test has to be validated on a large cohort of patients," said Dr. Lalazar, principal investigator on this study "but if it is validated, this noninvasive liver function test will be able to identify liver impairment at all stages of liver disease-both acute and chronic.'' He added, "We are now conducting large scale clinical trials to assess the role of the methacetin breath test for follow up and therapeutic decision making in patients with chronic hepatitis B and in non-alcoholic fatty liver disease."

The study was presented at the American Association for the Study of Liver Diseases (AASLD), held in Boston (MA, USA) from October 30-November 3, 2009.

John Hoefs, M.D., of the University of California, Irvine (USA) commented that quantitative tests of liver health such as the MBT appear to be more accurate than the usual clinical measures. Dr. Hoefs, who was not involved in the study, was part of a group that reported on a separate trial involving a panel of other quantitative tests, such as choline and antipyrine clearance and perfused hepatic mass. It also accurately predicted outcomes in patients with chronic viral hepatitis.

Related Links:
Hadassah Hebrew University Medical Center

United Network for Organ Sharing

American Association for the Study of Liver Diseases

University of California, Irvine