Utility of carbohydrate-deficient transferrin as a marker of relapse in alcoholic patients

Carbohydrate-deficient transferrin (CDT) has been proposed as a marker of alcoholism. However, its role in monitoring alcoholic patients for relapse has not been extensively studied. We therefore performed sequential serum CDT measurements using a microcolumn/radioimmunoassay method (Kabi Pharmacia, Piscataway, NJ) in 86 male alcoholics participating in a hepatitis vaccination program who were monitored for relapse using self-report and collateral history (when available). The maximum serum CDT was significantly higher in patients who relapsed (n = 38) (33.1 +/- 3.1 mg/liter), as compared with abstinent subjects with collateral verification (n = 39) (18.8 +/- 1.3, p < 0.001) and abstinent patients without collateral verification (n = 9) (17.4 +/- 1.3, p < 0.01). Using the manufacturer's currently recommended threshold of 20 mg/liter for males, serum CDT was elevated in 29 of 38 patients who relapsed (sensitivity 76.3%). In 16 (42.1%) of the relapsed patients, a serum CDT above this threshold preceded the patient's self-report by at least 28 days. However, serum CDT exceeded 20 mg/liter in 10 of 48 patients who remained sober (specificity 79.2%); three of these patients had clinical and/or pathological evidence of cirrhosis. Using a threshold of 25 mg/liter, 21 of 38 patients who relapsed had an elevated serum CDT (sensitivity 55.3%); 12 (31.6%) of these patients had elevated serum CDT before self-report. Only 4 of 48 subjects who remained sober had serum CDT levels that exceeded 25 mg/liter (specificity 91.7%); three of these patients had clinical and/or pathological evidence of cirrhosis. In conclusion, serial serum CDT testing detects relapses before self-report in male subjects. Values between 20-25 mg/liter suggest relapse, but call for collateral verification, whereas CDT values above 25 mg/liter are usually diagnostic of relapse in the absence of cirrhosis.