Lipoprotein-X and diagnosis of cholestasis: comparison with other biochemical parameters and liver biopsy.

The presence or absence of histological signs of cholestasis (on the basis of liver specimens obtained by means of liver biopsy) was compared with total bilirubin, alkaline phosphatase, gamma-glutamyl transpeptidase, ornithine carbamoyltransferase, serum glutamic oxaloacetic transaminase levels and LP-X test in 157 patients suffering from different liver diseases. The LP-X test was positive in 93% of the 59 cases in whom histological evidence of cholestasis was observed and negative 95% of the 98 cases in whom histological examination was negative. LP-X concurs more frequently with the histological picture than do total bilirubin and alkaline phosphatase. These data confirm that LP-X test is more specific than the tests traditionally used to demonstrate or exclude cholestasis. An increment in gamma-GT levels was observed in 97% of the patients with a positive LP-X test. These clinical results have been discussed in the light of recent data regarding the mechanism of lipoprotein-X formation and the possible relationships between LP-X and gamma-glutamyl transpeptidase.