Improved Diagnostic Classification of Alcohol Abusers by Combining Carbohydrate-Deficient Transferrin and [Gamma]-Glutamyltransferase (Enzymes and Protein Markers) (Clinical Report‪)‬

Alcohol abuse is associated with many health and social problems and brings high economic costs. It is estimated that at least 20% of adults who visit a physician have had an alcohol problem at one time (1), and 12-30% of patients admitted to an inpatient service (2) and 9-20% of patients admitted to a primary healthcare service screened positive for alcohol abuse (2, 3). Despite the high prevalence of alcohol-related problems among medical patients, usually fewer than one-half of the patients with alcohol problems are identified (2), and treatment is offered in even fewer cases (4). In management of alcohol problems, a crucial requirement is an effective and accurate procedure that will enable clinicians to identify alcohol abuse (5) and to monitor progress in treatment. Clinical laboratory procedures frequently are used to corroborate results of physicians' interviews and clinical examinations. Biological laboratory markers of alcohol abuse can provide objective evidence of excessive drinking, especially in patients who deny their drinking problems. Generally, the clinical utility of biological markers of high alcohol consumption is in detecting and monitoring excessive alcohol consumption as well as in differential diagnosis between alcohol- and nonalcohol-related disease. Unfortunately, an optimal marker of excessive drinking has not been found, either for men or for women. [Gamma]-Glutamyltransferase (GGT), (5) the most widely used marker, has a sensitivity of 34-85% (6-8) but a relatively low specificity. Increased GGT concentrations are also caused, e.g., by nonalcoholic liver disease, most hepatobiliary disorders, obesity, diabetes mellitus, hypertriglyceridemia, and the use of liver microsome-inducing drugs (6, 8-10). Carbohydrate-deficient transferrin (CDT) is a new marker for high alcohol consumption with a reported sensitivity of 31-91% and a high specificity (6, 7,11,12). False positives have been reported in patients with inborn errors of glycoprotein metabolism, the genetic D-variant of transferrin, severe nonalcoholic liver diseases such as primary biliary cirrhosis, and diseases with high total transferrin (12-15). In addition to GGT and CDT, aspartate aminotransferase (ASAT) and alanine aminotransferase (ALAT) as well as erythrocyte mean corpuscular volume (MCV) are frequently used as markers for alcohol abuse (6).