Transient elevation of serum bile salts after partial hepatectomy is due to metabolic overload and not to cholestasis

Validation of the peak bilirubin criterion for outcome after partial hepatectomy

INTRODUCTION

Postoperative liver failure (PLF) is a dreaded complication after partial hepatectomy. The peak bilirubin criterion (>7.0 mg/dL or ≥120 μmol/L) is used to define PLF. This study aimed to validate the peak bilirubin criterion as postoperative risk indicator for 90-day liver-related mortality.

METHODS

Characteristics of 956 consecutive patients who underwent partial hepatectomy at the Maastricht University Medical Centre or Royal Free London between 2005 and 2012 were analyzed by uni- and multivariable analyses with odds ratios (OR) and 95% confidence intervals (95%CI).

RESULTS

Thirty-five patients (3.7%) met the postoperative peak bilirubin criterion at median day 19 with a median bilirubin level of 183 [121-588] μmol/L. Sensitivity and specificity for liver-related mortality after major hepatectomy were 41.2% and 94.6%, respectively. The positive predictive value was 22.6%. Predictors of liver-related mortality were the peak bilirubin criterion (p < 0.001, OR = 15.9 [95%CI 5.2-48.7]), moderate-severe steatosis and fibrosis (p = 0.013, OR = 8.5 [95%CI 1.6-46.6]), ASA 3-4 (p = 0.047, OR = 3.0 [95%CI 1.0-8.8]) and age (p = 0.044, OR = 1.1 [95%CI 1.0-1.1]).

CONCLUSION

The peak bilirubin criterion has a low sensitivity and positive predictive value for 90-day liver-related mortality after major hepatectomy.

Regulation of bile acid homeostasis by the intestinal Diet1-FGF15/19 axis

PURPOSE OF REVIEW

Hepatic bile acid synthesis is controlled, in part, by a complex enterohepatic feedback regulatory mechanism. In this review, we focus on the role of the intestinal FGF15/19 hormone in modulating bile acid levels, and additional metabolic effects on glucose metabolism, nonalcoholic liver disease (NAFLD), and liver regeneration. We also highlight the newly identified intestinal protein, Diet1, which is a modulator of FGF15/19 levels.

RECENT FINDINGS

Low FGF19 levels are associated with bile acid diarrhea and NAFLD. In contrast, high FGF19 levels are associated with diabetes remission following Roux-en-Y gastric bypass surgery, suggesting new therapeutic approaches against type 2 diabetes. The effect of FGF15/19 on liver plasticity is a double-edged sword: whereas elevated FGF15/19 levels improve survival of mice after partial hepatectomy, FGF19 mitogenic activity is associated with liver carcinoma. Finally, a recent study has identified Diet1, an intestinal factor that influences FGF15/19 levels in mouse intestine and human enterocytes. Diet1 represents the first factor shown to influence FGF15/19 levels at a post-transcriptional level.

SUMMARY

The biological effects of FGF15/19 make it an attractive target for treating metabolic dysregulation underlying conditions such as fatty liver and type 2 diabetes. Further elucidation of the role of Diet1 in FGF15/19 secretion may provide a control point for the pharmacological modulation of FGF15/19 levels.