Clinical value of 13C-methacetin breath test for assessing liver function in patients with cirrhosis

Objective To investigate the clinical value of the 13C-methacetin breath test (MBT) for assessing liver function in patients with cirrhosis.Methods One-hundred-thirty-nine patients with liver cirrhosis, 34 hepatitis patients, and 22 healthy controls were studied.Patients with cirrhosis were divided into groups according to Child-Pugh score and model of end-stage liver disease (MELD) score.All study participants underwent 13C-MBT.The three major parameters of 13C-MBT were recorded (maximum excretion rate before 40 min (MVmax40) , 13CO2 cumulative excretion of 40 min (CUM40) and 120 min (CUM120) and used in a comparative analysis to determine association with Child-Pugh score, MELD score, liver and spleen volume (assessed by computed tomography) , and liver function parameters (assessed by standard biochemical assays) .Results As severity of liver damage increased, the MVmax40, CUM40, and CUM120 decreased.The 13C-MBT classification was consistent with Child-Pugh classification (κ=0.57, P<0.05) and MELD classification (κ=0.41, P<0.05) .In cirrhosis patients, the 13C-MBT parameters were negatively correlated with Child-Pugh score, MELD score, total bilirubin, international normalized ratio, and spleen volume (all P<0.01) , but positively correlated with albumin, prealbumin, prothrombin time activity, and serum cholinesterase (all P<0.05) , and not correlated with creatinine, alanine aminotransferase, or liver volume (all P>0.05) .In 68 patients with hepatitis B virus infection and cirrhosis, the liver volumes were obviously reduced with increasing Child-Pugh score and MELD score.The 13C-MBT parameters were positively correlated with liver volume.Conclusion The 13C-methacetin breath test is a useful tool to measure the extent of hepatocyte injury and liver functional reserve.