Nephelometric determination of carbohydrate deficient transferrin

Abstract

We describe a technique for measuring carbohydrate-deficient transferrin (CDT) in serum. Serum transferrin fractions are separated by anion-exchange chromatography on microcolumns. Sialic acid-deficient transferrin fractions are collected in the eluate, and transferrin is then quantified by a rate-nephelometric technique. Imprecision (CV) was 4-5% within-run and 7-9% between runs (n = 15). Comparison with an isoelectric focusing-immunofixation method for transferrin index (x) yielded y = 761x + 7, Sy/x = 39 mg/L. Assay of sera from 90 abstainers or moderate consumers of alcohol showed that 81 (90%) had CDT concentrations between 30 and 70 mg/L. Among 74 alcoholics admitted to an alcohol treatment center, 54 (73%) had CDT > 70 mg/L, i.e., the diagnostic sensitivity was 73% at a specificity of 90% (area under receiver-operator characteristic curve = 0.891).

Dose–effect Relation Between Daily Ethanol Intake in the Range 0–70 Grams and %Cdt Value: Validation of a Cut-Off Value

“…As shown in Table 1, we observed the absence of sex difference in teetotallers (RG). This result is in agreement with results obtained using a very similar method (Schellenberg et al, 1996) for CDT measurement, and more recent data (Schwan et al, 2004) obtained with this %CDT method. This finding confirms the validity of one unique cut-off value for men and women, as proposed by the manufacturer.…”

Objective Diagnosis of Alcohol Abuse: Compared Values of Carbohydrate-Deficient Transferrin (CDT), ??-Glutamyl Transferase (GGT), and Mean Corpuscular Volume (MCV)

“…These results are similar to those of Lesch et al (1996), obtained during experimental consumption of large amounts of alcohol by healthy subjects, and they reflect better sensitivity in the population of abusers than for the heavy drinkers reported by Sillanaukee (1996). This is readily understandable, because the inclusion threshold for the latter study was consumption of 40 g/day for men and 25 g/day for women, which is rather low to produce a positive effect on CDT (Allen et al, 1992;Mihas and Tavassoli, 1992;Schellenberg et al, 1989Schellenberg et al, , 1996Stibler, 1991). These results must be compared with those of Yersin et al (1995) (sensitivity of 58%, specificity of 82%), in which the recruitment included abusers and dependents.…”

“…CDT was measured by immunonephelometric assay based on microisocratic anion-exchange chromatography, following a method described by Schellenberg and Weill (Schellenberg et al, 1996). The serum was stored at Ϫ20°C until assayed.…”

Determination of carbohydrate‐deficient transferrin separated by lectin affinity chromatography for detecting chronic alcohol abuse

“…Several methods based on isocratic anion exchange chromatography followed by immunoassays have been developed for its measurement [1,6]. However, recent studies have shown false‐positive CDT test results for individuals with one of several non‐alcoholic liver diseases causing hyposialylation by fucosylation [7–11] and some genetic variants causing a shift of isoelectric point [1,12], because the separation of the CDT fraction from non‐specific isoforms is insufficient by charge‐based separation procedures, owing to the close isoelectric points [6,13]. Unfortunately, because patients with CAA often suffer from liver diseases, their abnormal transferrin isoforms consist of hyposialylated transferrins and deglycosylated transferrins.…”