Determination of serum bile acids routinely may prevent delay in diagnosis of total parenteral nutrition-induced cholestasis

BACKGROUND/PURPOSE: Early diagnosis of development of cholestasis is a current major problem for patients receiving total parenteral nutrition (TPN). Conventional tests for hepatic function such as serum transaminases and alkaline phosphatase do not often reflect simultaneously histopathologic changes of the liver. The aim of this study is to find out the relationships between conventional hepatic function tests, total serum bile acid concentrations (TSBA), and the histopathologic changes in the liver during TPN administration in rats. METHODS: Forty Albino rats were divided into four experimental groups, each consisting of 10 rats, as follows: control group (C), 0.9% saline for 14 days; T7 group, TPN for 7 days; T14 group, TPN for 14 days; T7O7 group, TPN for 7 days and then 0.9% saline for the next 7 days. All solutions were administered by infusion through intraperitoneal catheter in two equal doses. During the experiment, rats also maintained on rat chow and water ad libitum. Levels of serum glutamic oxaloacetic transaminase, glutamic pyruvic transaminase, alkaline phosphatase, and TSBA were measured. Liver was evaluated histopathologically by light microscope and then Morphological Cholestasis Index (MCI) was calculated. RESULTS: Cholestasis was present in all experimental groups except control. Levels of transaminases and alkaline phosphatase were not correlated with the histopathologic changes (P > .05), but TSBA concentrations were correlated with MCI in all groups (P< .01). TSBA concentrations and MCI in all groups also were correlated with the duration of exposure with TPN (P< .01). CONCLUSIONS: Measurement of TSBA seems to be more sensitive in early diagnosis of TPN-induced cholestasis. Therefore, periodical determination of TSBA during TPN administration can be done routinely.