SERUM MALONDIALDEHYDE AND MITOCHONDRIAL ASPARTATE-AMINOTRANSFERASE ACTIVITY AS MARKERS OF CHRONIC ALCOHOL INTAKE AND ALCOHOLIC LIVER-DISEASE

Since lipid peroxidation is a well know mechanism of alcohol-related liver damage, the aim of the present study was to assess the role of serum malondialdehyde (MDA), a secondary product of lipoperoxidation, in the detection of alcoholism and different stages of alcoholic liver disease and to correlate serum levels of malondialdehyde with other markers. Sixty-five patients with a mean alcohol intake of 151 gr/day, were divided into three groups: alcoholics with normal liver function (ANLF, 7 pts), non-cirrhotic alcoholic liver disease (NCALD, 26 pts) and alcoholic cirrhosis (ALC, 32 pts). The control group consisted of 15 healthy subjects. Serum MDA was measured by the thiobarbituric acid reaction test, and mitochondrial aspartate aminotransferase (mAST) with immunochemical assay. MDA had a higher sensitivity (70% vs 37.5%) and specificity (100% vs 93%) than mAST in detecting alcohol abuse, irrespective of the presence of liver disease. Serum MDA levels were significantly higher in all three groups than in controls (2.3 +/- 0.1 nmol/ml), the highest value being found in NCALD (4.6 +/- 0.4). Serum MDA levels were correlated with prothrombin time (p<0.005) and blood alcohol levels (p<0.05). mAST serum activity was also significantly higher in all three groups than in controls. A significant correlation was found between serum MDA and mAST only when the whole group was considered. In conclusion, MDA seems more accurate than mAST in detecting alcohol abuse. Increased lipid peroxidation is more evident in less advanced liver disease and its correlation with other indexes of synthetic function indicates its dependence on the preserved liver cell metabolic activity.