Carbohydrate-deficient transferrin isoforms measured by capillary zone electrophoresis for detection of alcohol abuse.
BACKGROUND
Measurements of carbohydrate-deficient transferrin (CDT) are used as markers of alcohol abuse. We developed a capillary zone electrophoresis (CZE) method aimed at improving accuracy of CDT testing.


METHODS
We studied 111 alcohol abusers with Alcohol Use Disorders Identification Test scores >11 and 50 teetotalers. CZE was performed with a P/ACE 5500, fused-silica capillaries, and a CEofix CDT reagent set. After iron saturation, sera were loaded by low-pressure injection, separated at 28 kV, and monitored at 214 nm. We identified the transferrin isoforms by migration times, treatment with 100 U/L neuraminidase, and immunosubtraction with anti-human transferrin and anti-C-reactive protein antibodies. We compared CZE results with current biological markers of alcohol abuse, including the %CDT turbidimetric immunoassay.


RESULTS
Migration times of the isoforms were identical in both populations. Asialotransferrin was missing in teetotalers but present in 92% of alcohol abusers. Disialotransferrin was higher in those who consumed excessive amounts of alcohol, whereas mean trisialotransferrin concentration was not affected by alcohol abuse. At cutoffs to maximize sensitivity and specificity, these values were 0.92 and 1 [mean ROC area (MRa), 0.96; 95% confidence interval (CI), 0.93-0.99] for asialotransferrin; 0.84 and 0.94 for the sum of asialo- + disialotransferrin (MRa, 0.94; 95% CI, 0.91-0.98); 0.79 and 0.94 for disialotransferrin (MRa, 0.89; 95% CI, 0.84-0.94); 0.62 and 0.53 for trisialotransferrin (MRa, 0.58; 95% CI, 0.49-0.68); 0.79 and 0.82 for a 3% %CDT; and 0.83 and 0.69 for a 2.6% cutoff (MRa, 0.87; 95% CI, 0.81-0.92). Current markers lack sensitivity (<0.65). Transferrins were not significantly correlated with serum enzymes and mean erythrocyte volume.


CONCLUSIONS
CZE-isolated desialylated transferrin isoforms allowed differentiation between chronic alcohol abusers and teetotalers.
Legros
Franz J
FJ
Laboratory of Experimental Medicine, Université Libre de Bruxelles and Centre Hospitalier Universitaire André Vésale, 706, route de Gozée, B6110 Montigny-le-Tilleul, Belgium. franz.legros@chu-charleroi.be
Nuyens
Vincent
V
Minet
Eddy
E
Emonts
Philippe
P
Boudjeltia
Karim Zouaoui
KZ
Courbe
Anne
A
Ruelle
Jean-Luc
JL
Colicis
Jacques
J
de L'Escaille
Francois
F
Henry
Jean-Pol
JP
D000328:Adult; D000437:Alcoholism / Q000175:diagnosis*; D015415:Biomarkers / Q000097:blood; D002852:Chromatography, Ion Exchange; D019075:Electrophoresis, Capillary; D005260:Female; D006801:Humans; D008297:Male; D009391:Nephelometry and Turbidimetry; D020033:Protein Isoforms; D012372:ROC Curve; D014168:Transferrin / Q000031:analogs & derivatives* / Q000032:analysis*
D015415:Biomarkers; D020033:Protein Isoforms; D014168:Transferrin; C056759:carbohydrate-deficient transferrin