title: Comparison of the Axis %CDT TIA and the CDTect method as laboratory tests of alcohol abuse.
abstract: Carbohydrate-deficient transferrin (CDT) has been suggested as a specific marker of alcohol abuse. We designed this study to compare the conventional CDTect method (Pharmacia & Upjohn) and the new semiautomated Axis %CDT turbidimetric immunoassay (%CDT TIA) for their diagnostic performance to identify problem drinking. The sensitivities of the %CDT TIA and CDTect for correctly classifying heavy drinkers (n = 90) were 29% and 59% with the thresholds currently recommended by the manufacturers, respectively. In the control group (n = 114), which included hospitalized patients with abnormal serum transferrin concentrations, the CDTect assay gave 21 false-positive values (18%), whereas the %CDT TIA showed 100% specificity. With the cutoff limits based on the present healthy control group (mean + 2 SD), the sensitivities of the %CDT TIA and CDTect were 61% and 86%, respectively. For men, the ROC plot area of the CDTect results in comparisons of alcohol abusers and healthy controls was significantly (P < 0.05) higher than that of the %CDT TIA results, whereas for women, there was no significant difference in this respect. The slope and intercept (with 95% confidence intervals) for linear regression between CDTect and %CDT TIA were 0.13 (0.12-0.15) and 1.16 (0.73-1.59), respectively (S(y/x) = 1.51, r = 0.744). CDTect results correlated positively with serum transferrin (r = 0.224, P < 0.001), whereas the %CDT TIA results showed a slight inverse correlation with serum transferrin (r = -0.132, P = 0.07). The data suggest that CDTect is more sensitive than %CDT TIA in detecting drinking problems. However, the %CDT TIA method yields more specificity when analyzing samples from patients with high serum transferrin concentrations.
authors.affiliation: EP Central Hospital Laboratory, Seinäjoki, Finland.
authors.forename: K
authors.initials: K
authors.lastname: Viitala
authors.forename: K
authors.initials: K
authors.lastname: Lähdesmäki
authors.forename: O
authors.initials: O
authors.lastname: Niemelä
mesh_terms: D000437:Alcoholism / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007118:Immunoassay; D008104:Liver Cirrhosis, Alcoholic / Q000097:blood; D008297:Male; D009391:Nephelometry and Turbidimetry; D011933:Reagent Kits, Diagnostic; D012680:Sensitivity and Specificity; D014168:Transferrin / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D015415:Biomarkers; D011933:Reagent Kits, Diagnostic; D014168:Transferrin; C056759:carbohydrate-deficient transferrin