Abstract: Objective To investigate the characteristics and diagnostic value of hepatobiliary biochemical indexes of drug-induced cholestasis. Methods A total of 135 inpatients with drug-induced liver injury (DILI), bile duct stones (CBDS) or primary biliary cholangitis (PBC) admitted to our hospital from January 2012 to July were included. They were randomly divided into 3 groups.. A series of assay indexes were recorded, including total bile acid (TBA), total bilirubin (TBil), gamma-glutamyltransferase (GGT), alkaline phosphatase (ALP), 5-nucleotidase (5'-NT), alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Normality test, one-way analysis of variance, rank sum test, chi-square test and receiver operating characteristic (ROC) curve analysis were performed through SPSS software. Results TBA level of DILI group was significantly higher than those of PBC and CBDS group (P<0.05). TBil level of DILI group was significantly higher than that of PBC group (P<0.05). However, there was no statistical difference of TBil level between DILI group and CBDS group (P>0.05). GGT level of DILI group was significantly lower than those of CBDS and PBC group (P<0.05). The 5'-NT level of DILI group was significantly lower than that of CBDS group (P<0.05). However, there was no statistical difference of 5'-NT level between DILI and PBC group (P>0.05). There was no statistical difference in ALP level among three groups (P>0.05). The ROC curve of the DILI group showed that the area under the curve (AUC) of TBA level was 0.990, P=0.000, the cut-off value was 120.2μmol/L, and its sensitivity and specificity were 97.4% and 100%, respectively. The AUC of ALP : GGT ratio of DILI group was 0.930, P=0.000, the cut-off value was 0.74 (1∶1.35), its sensitivity and specificity were 89.5% and 89.5%, respectively. The AUC of TBil level in DILI group was 0.751, P=0.000, its cut-off value was 171.62μmol/L, its sensitivity and specificity were 100% and 55.8%, respectively. There was no significant difference in ROC curve analysis of ALP, 5'-NT and GGT levels of the DILI group. Conclusion Among different kinds of cholestasis, TBA level of drug-induced cholestasis is the highest and GGT level of drug-inducedI is the lowest, which may be a typical manifestation. Secondly, 5'-NT level of drug-induced cholestasis is significantly lower than that of CBDS, but similar to that of PBC. There is no statistical difference in ALP level among different kinds of cholestasis. The cut-off value of TBA level and ALP/ GGT ratio perform especially well in diagnosing drug-induced cholestasis,and showing excellent sensitivity and specificity.

Key words: Drug-induced cholestasis, Total bile acid, 5'-nucleotidase, Alkaline phosphatase, Gamma-glutamyl transpeptidase, Total bilirubin, Comparative study, Receiver operating characteristic curve analysis