[Serum activity of mitochondrial aspartate aminotransferase and extrahepatic cholestasis].

Serum mitochondrial aspartate aminotransferase (mAST) level and the mitochondrial aspartate aminotransferase/total aspartate aminotransferase ratio (mAST/AST) have been proposed as sensitive markers of chronic alcoholism. Their specificity, however, remains poorly defined. The purpose of this study was to compare these markers in three groups of hospitalized patients: group I, 80 patients with chronic alcoholic liver disease; group II, 51 patients with chronic liver disease without alcoholism; group III, 44 patients with extrahepatic cholestasis (due to choledocholithiasis in 21 and malignant in 23). mAST was measured after immuno-precipitation of cytoplasmic aspartate aminotransferase. The normal values of mAST (less than or equal to 2 mu/l) and mAST/AST (less than or equal to 6 p. 100) were defined in a group of 59 non alcoholic subjects without liver disease (controls). mAST was increased as compared with controls in 91 p. 100 of the patients of group I, 20 p. 100 of group II, 61 p. 100 of group III. mAST was comparable in groups I (mean +/- SD: 10 +/- 10.8) and III (10.3 +/- 12.9), and higher than in group II (1.8 +/- 2.4). m/AST was increased in 59 p. 100 of the patients of group I, 6 p. 100 of group II and 36 p. 100 of group III. It was higher in group I (8 +/- 4 p. 100) than in group III (6 +/- 4 p. 100, p less than 0.02), and particularly higher in both these groups than in group II (2 +/- 1 p. 100, p less than 0.00001). mAST was correlated to AST in each of these three groups.(ABSTRACT TRUNCATED AT 250 WORDS)