Objective diagnosis of alcohol abuse: compared values of carbohydrate-deficient transferrin (CDT), gamma-glutamyl transferase (GGT), and mean corpuscular volume (MCV).

BACKGROUND: Alcohol abuse is roughly twice as common as alcohol dependence. Subjects with alcohol problems are usually diagnosed only when medical complications are present. Therefore, both doctors and patients need a method for early diagnosis of alcohol abuse. METHODS: The mean corpuscular volume, gamma-glutamyl transferase, and carbohydrate-deficient transferrin in alcohol abusers, alcohol-dependent patients, and "nonalcohol hospital" individuals were compared. RESULTS: For objective diagnosis of alcohol abuse, we found a sensitivity of 24%, a specificity of 96%, and a global predictive value of 63% for mean corpuscular volume; a sensitivity of 42%, a specificity of 76%, and a global predictive value of 61% for gamma-glutamyl transferase; and a sensitivity of 67%, a specificity of 97%, and a global predictive value of 84% for carbohydrate-deficient transferrin. CONCLUSIONS: Carbohydrate-deficient transferrin proves to be the best marker of alcohol abuse. It allows objective detection so that therapeutic action can be started early, which is easier and more effective than in alcohol dependence.

Usefulness of carbohydrate-deficient transferrin in alcoholic patients with normal gamma-glutamyltranspeptidase.

The biological diagnosis of alcoholism is conducted routinely by assay of gamma-glutamyltranspeptidase (GGT) and mean corpuscular volume (MCV). However, their low specificity and sensitivity have prompted research to find other more reliable parameters. Stibler showed an increase in desialylated transferrin [carbohydrate-deficient transferrin (CDT)] in alcoholic patients. The normal value of the serum CDT concentration is under 60 mg/liter; a value between 60 and 100 mg/liter indicates probable alcoholism, and a value > 100 mg/liter indicates a very high probability of alcoholism (specificity: 99%). Its sensitivity ranges from 60 to 91%, and its specificity ranges from 92 to 100%. Its half-life is 17 +/- 4 days. CDT is thus a useful laboratory marker, but its assay is costlier and more complex than that of GGT. This study concerns 31 alcohol-dependent patients as defined by DSM-IV, with GGT levels in the normal range. It evaluates CDT at day 0 and its time course after 15 days withdrawal. GGT and MCV were assayed concomitantly. Remarkably, the results show a sensitivity of 83.9 (26 positives of 31) in this particular population and a specificity of 92.2. The fall in CDT after 15 days withdrawal was 36%. CDT is thus a particularly useful marker for the diagnosis and follow-up of alcoholics with normal GGT levels.