Diagnosis and therapy of cholestatic liver disease

ACR Appropriateness Criteria® Abnormal Liver Function Tests

Liver function tests are commonly obtained in symptomatic and asymptomatic patients. Various overlapping lab patterns can be seen due to derangement of hepatocytes and bile ducts function. Imaging tests are pursued to identify underlying etiology and guide management based on the lab results. Liver function tests may reveal mild, moderate, or severe hepatocellular predominance and can be seen in alcoholic and nonalcoholic liver disease, acute hepatitis, and acute liver injury due to other causes. Cholestatic pattern with elevated alkaline phosphatase with or without elevated γ-glutamyl transpeptidase can be seen with various causes of obstructive biliopathy. Acute or subacute cholestasis with conjugated or unconjugated hyperbilirubinemia can be seen due to prehepatic, intrahepatic, or posthepatic causes. We discuss the initial and complementary imaging modalities to be used in clinical scenarios presenting with abnormal liver function tests. The American College of Radiology Appropriateness Criteria are evidence-based guidelines for specific clinical conditions that are reviewed annually by a multidisciplinary expert panel. The guideline development and revision process support the systematic analysis of the medical literature from peer reviewed journals. Established methodology principles such as Grading of Recommendations Assessment, Development, and Evaluation or GRADE are adapted to evaluate the evidence. The RAND/UCLA Appropriateness Method User Manual provides the methodology to determine the appropriateness of imaging and treatment procedures for specific clinical scenarios. In those instances where peer reviewed literature is lacking or equivocal, experts may be the primary evidentiary source available to formulate a recommendation.

Prognostic value of direct bilirubin in neonatal hyperbilirubinemia

OBJECTIVE

To determine the prognostic value of indirect and direct hyperbilirubinemia in neonates with jaundice.

METHODS

A cohort of 92 consecutive neonates reporting with hyperbilirubinemia to a tertiary care center were followed up till well and discharged, or, till death to assess risk and rate of mortality.

RESULTS

The baseline median values of total, direct and indirect bilirubin in the cohort of 21.8, 1.6 and 18.6 mg/dl, respectively, were used as cut-offs for high and low levels. Using survival analyses i.e. Kaplan-Meier plots, logrank tests and multivariate Cox proportional hazards regression models to adjust for other strong predictors such as receipt of breastfeeding, being small for gestational age (SGA) and exchange transfusion, high direct bilirubin (> or = median value of 1.6 mg/dl) was independently associated with a higher and faster mortality.

CONCLUSION

This study showed that direct bilirubin has independent and additive prognostic value and due attention should be given to newborns with raised levels.

The role of inositol 1,4,5-trisphosphate receptors in the regulation of bile secretion in health and disease

Ca2+ signaling via the inositol 1,4,5-trisphosphate receptor (InsP3R) is a ubiquitous mechanism for regulation of cell function, yet very little is known about the role of the InsP3R in specific disease states. Converging lines of evidence suggest that the liver may provide a model for the role of the InsP3R in health and disease. Ca2+ signaling is mediated entirely by the InsP3R in hepatocytes and cholangiocytes, the two types of epithelia in the liver. Here we review the role of specific InsP3R isoforms and the physiological effects of InsP3R-mediated Ca2+ signals in both of these types of epithelia. In addition, we review evidence that the InsP3R is lost from cholangiocytes in cholestatic forms of liver disease, and discuss this as a possible final common pathway for cholestasis.

Pharmacokinetics and pharmacodynamic action of budesonide in early- and late-stage primary biliary cirrhosis

Budesonide has been discussed as a potential treatment option in primary biliary cirrhosis (PBC). Therefore, we studied the pharmacokinetics and pharmacodynamics of budesonide in patients with PBC stage I/II and stage IV. Twelve patients with early PBC stage I/II and 7 patients with PBC stage IV under continuous treatment with ursodeoxycholic acid (UDCA) were enrolled in an exploratory trial. Each patient received oral budesonide for 3 weeks at weekly increasing dosages of 3 mg once to thrice per day. Budesonide and cortisol plasma levels, urinary cortisol excretion, serum liver tests, and immunoglobulins were determined on days 1, 7, and 21 of the study. Patients with PBC stage IV showed significantly higher peak plasma concentrations (4.9 +/- 3.5 vs. 1.5 +/- 0.4 ng/mL; P <.05) and areas under the plasma concentration-time curves (AUC) (23.2 +/- 16.8 vs. 5.1 +/- 1.4 hours. ng/mL, P <.01, total AUC extrapolated to infinity [AUC(0- infinity )]) after a single dose of 3 mg budesonide when compared with patients with PBC stage I/II. Equally, AUC of budesonide were significantly increased under a multiple dose regimen on day 21 (14.0 +/- 11.6 vs. 5.0 +/- 1.9 hours. ng/mL, P <.01, AUC at steady state from dosing time to 8 hours [AUC(ss,0-8 h)]). Higher levels of budesonide were related to a significant decrease in plasma cortisol and reduction of urinary cortisol excretion in patients with stage IV disease. Two patients with stage IV disease developed portal vein thrombosis (PVT). In conclusion, administration of budesonide leads to markedly elevated plasma levels in cirrhotic patients with PBC associated with serious adverse drug reactions. Thus, further evaluation of combined treatment with UDCA may be considered in early-stage PBC but not in cirrhotic patients with PBC.

Cetirizine-induce cholestasis

Cetirizine, a human metabolite of hydroxyzine, is a selective H1-receptor antagonist currently approved for the treatment of seasonal allergic rhinitis, perennial allergic rhinitis, and chronic urticaria. In U.S. clinical trials, transient reversible hepatic transaminase elevations were observed in <2% of patients during cetirizine therapy. We report a case of cetirizine-induced cholestasis in a 28-year-old man with no previous hepatobiliary disease after a 2-year period of taking cetirizine on a daily basis. The treatment of this patient included the use of ursodeoxycholic acid, as well as hydroxyzine, for symptomatic relief of pruritus. In light of the patient's clinical and biochemical improvement while using hydroxyzine, it appears that the hepatic metabolism of hydroxyzine to metabolites, including cetirizine, is not involved in the pathogenesis of this particular case of drug-induced hepatotoxicity. Cetirizine should be considered as a potential cause of drug-induced cholestasis.

Stimulation of bile duct epithelial secretion by glybenclamide in normal and cholestatic rat liver

Cholestasis is a cardinal complication of liver disease, but most treatments are merely supportive. Here we report that the sulfonylurea glybenclamide potently stimulates bile flow and bicarbonate excretion in the isolated perfused rat liver. Video-microscopic studies of isolated hepatocyte couplets and isolated bile duct segments show that this stimulatory effect occurs at the level of the bile duct epithelium, rather than through hepatocytes. Measurements of cAMP, cytosolic pH, and Ca2+ in isolated bile duct cells suggest that glybenclamide directly activates Na+-K+-2Cl- cotransport, rather than other transporters or conventional second-messenger systems that link to secretory pathways in these cells. Finally, studies in livers from rats with endotoxin- or estrogen-induced cholestasis show that glybenclamide retains its stimulatory effects on bile flow and bicarbonate excretion even under these conditions. These findings suggest that bile duct epithelia may represent an important new therapeutic target for treatment of cholestatic disorders.