Reduced Serum Cholinesterase Activity Distinguishes Hepatic Encephalopathy From 48 Types of Human Diseases

Background: Hepatic encephalopathy is a complication of central nervous systems due to liver failure-related brain inflammation. Less than half of patients suffering from liver failure develop hepatic encephalopathy, which suggests other factors beyond liver failure might contribute to hepatic encephalopathy. Indeed, we reported previously that the levels of serum direct bilirubin, a liver cell-made product, are counter-intuitively highest in hepatic encephalopathy patients among 72 clinically defined diseases. In current study, we tested if cholinesterase could serve as a biomarker for hepatic encephalopathy by comparing serum cholinesterase activities among 48 different types of human diseases.Methods: The activity of serum cholinesterase was determined by the standard “continuous monitoring method” in the clinical laboratory of the hospital where the serum cholinesterase activities from 137,305 independent tests with 48 clinically defined diseases and 3,387 independent tests from healthy individuals who came to the hospital for physical examination during the past 5 years were retrieved. All data were analyzed with RStudio V.1.3.1073 and python libraries 3.8.Results: We found that all 48 types of diseases had decreased cholinesterase activity compared to control based on either mean or median values. Remarkably, hepatic encephalopathy had the lowest cholinesterase activity and the serum cholinesterase activity was the best biomarker for hepatic encephalopathy (AUC 0.99, sensitivity 100%, and specificity 99%) among all diseases. Moreover, two component analysis of cholinesterase activity distributions revealed hepatic encephalopathy resembled preeclampsia and uremia whereas cirrhosis resembled multiple myeloma, leukemia, myeloproliferative disorder, and liver cancer.Conclusions: Decreased cholinesterase activity was an almost perfect serum biomarker for patients suffering hepatic encephalopathy at all stages. The resemblance of hepatic encephalopathy to preeclampsia and uremia based on cholinesterase activities provided new insight in understanding hepatic encephalopathy etiology beyond liver failure.

Assay of serum cholinesterase activity by an amperometric biosensor based on a co-crosslinked choline oxidase/overoxidized polypyrrole bilayer

Based on choline oxidase immobilized by co-crosslinking on an overoxidised polypyrrole modified platinum electrode, a novel electrochemical assay for cholinesterase activity in human serum was developed.