Aim: Choline is a dietary component that is crucial for normal cellular function. Choline is predominantly absorbed from the small intestine and completely metabolized in the liver. We recently demonstrated that free choline (fCh) levels in blood reflect the level of phosphatidylcholine synthesis in the liver and is correlated with the onset of non-alcoholic steatohepatitis (NASH). Our aim here was to validate the utility of this biomarker for NASH diagnosis.
Methods: Our cohort consisted of 110 patients with biopsy proven non-alcoholic fatty liver disease (NAFLD) from four centers across Japan and 25 age-matched healthy controls. Plasma fCh levels were measured using high-performance liquid chromatography.
Results: Patients with diagnosed or borderline NASH had significantly increased plasma fCh levels when compared with control subjects, or patients not diagnosed with NASH. Interestingly, an association between plasma fCh levels and expression of microsomal triglyceride transfer protein, which catalyzes the transfer of triglyceride, was reflected in the markedly negative correlation between these two variables in patients with NAFLD. Moreover, the grade of liver steatosis and fibrosis stage increased with increasing plasma fCh levels (P < 0.05). The area under the receiver-operating characteristic (ROC) curves for NASH, including borderline diagnosis, was 0.811. Additionally, the areas under the ROC for fibrosis stage were 0.816 for >stage 1, 0.805 for >stage 2, 0.809 for >stage 3 and 0.818 for >stage 4.
Conclusion: Plasma fCh levels are closely related to the grade of liver steatosis and fibrosis, and predict NASH severity. Plasma fCh levels are therefore a potential diagnostic marker for early-stage NASH in clinical practice.
© 2012 The Japan Society of Hepatology.