Effect of biliary drainage on serum 7 alpha-hydroxycholesterol level in patients with obstructive jaundice

Percutaneous transhepatic biliary drainage was performed in 15 patients with obstructive jaundice and the serum 7 alpha-hydroxycholesterol level was monitored for 2 weeks by capillary gas-liquid chromatography-mass spectrometry. Before biliary drainage, the serum 7 alpha-hydroxycholesterol level was 130 +/- 52 pmole/ml, which was significantly lower than the normal value (238 +/- 100 pmole/ml). After biliary drainage, the serum 7 alpha-hydroxycholesterol level was decreased to 117 +/- 48 pmole/ml on the first day. There were two groups of patients as classified by the behavior of the serum 7 alpha-hydroxycholesterol level after the third day. In one group of patients (responders), the serum level increased significantly up to 525 +/- 83 pmole/ml at the end of the 2 weeks. In another group (nonresponders), the serum level did not increase and remained 145 +/- 86 pmole/ml. The serum bilirubin level tended to improve faster in the responders (decline index = -0.234 +/- 0.152) than in the nonresponders (decline index = -0.057 +/- 0.067; P < 0.05) and a statistically significant correlation was found between the decline index and the total 7 alpha-hydroxycholesterol level on Days 7 or 14. As the serum 7 alpha-hydroxycholesterol level is considered to reflect hepatic bile acid synthesis, which is one of the important functions of the liver, we conclude that the increased serum 7 alpha-hydroxycholesterol level after biliary drainage in the responders indicates recovered liver function and that the low serum level in the nonresponders suggests more severe hepatocellular damage in patients with obstructive jaundice.