A new modified γ-%CDT method improves the detection of problem drinking:: studies in alcoholics with or without liver disease

Background. The detection of excessive alcohol consumption by laboratory methods continues to lack sensitivity and specificity. Recent studies have suggested that diagnostic improvement may be achieved by combining carbohydrate-deficient transferrin (CDT) and gamma-glutamyltransferase (GT) measurements into a marker defined as gamma-CDT. Methods: We developed a new approach for determining gamma-CDT by using the data obtained from the Axis %CDT turbidimetric assays. Marker results were compared in the assessment of 65 alcoholics, who were either with (n=34) or without (n=31) liver disease, as analysed by clinical, laboratory, and morphological criteria. Reference individuals were 45 healthy volunteers who were either social drinkers or abstainers. Results: Gamma-GT and CDT results derived from both CDTect and %CDT measurements were used to calculate marker ratios as follows 0.8 X ln(GT) + 1.3 x ln(CDT). With the established cut-off of 4.0 for the gamma-%CDT, the sensitivity of this method was 94% for men and 82% for women, as compared to 61% and 46% for %CDT and 70% and 73% for GT. The gamma-%CDT method was less dependent on liver status than the various other markers and showed the highest correlation with self-reported alcohol consumption (r = 0.7254). Conclusions: The data indicates that the new gamma-%CDT method yields improved diagnostic accuracy for the detection of excessive ethanol consumption. (C) 2003 Elsevier B.V. All rights reserved.