CDTect-RIA AND CDTect-EIA FOR DETERMINATION OF SERUM CARBOHYDRATE-DEFICIENT TRANSFERRIN COMPARED

Abstract

CDTect-RIA and CDTect-EIA for determination of serum carbohydrate-deficient transferrin (CDT) by radioimmunoassay and enzyme immunoassay respectively were tested for equality and precision in four European laboratories. For correlational studies, serum samples with CDT concentrations up to 130 U/l were analysed in accordance with a uniform trial schedule. The regression of CDT values obtained by the two procedures was computed for each laboratory using the method of Passing and Bablok. Slopes and intercepts of the regression functions did not differ significantly from the values 1 or 0, as proved by the corresponding 95% confidence intervals. Precision studies were computed using analysis of variance. For CDT concentrations at the upper reference limit for men, the within-day coefficients of variation (CVs) ranged between 0.7 and 6.4% (median 5.2%) for CDTect-RIA and from 4.3 to 9.2% (median 6.2%) for CDTect-EIA. The corresponding pure between-day CVs were 5.0-18.5% (median 9.8%) and 3.5-14.5% (median 10.9%). The study demonstrates the equality of CDT values obtained by CDTect-RIA and CDTect-EIA. According to this study, the two methods can be used interchangeably without getting fluctuating CDT values, e.g. in longitudinal studies.

Evaluation of the Cut-off for Serum Carbohydrate-deficient Transferrin as a Marker of Chronic Alcohol Abuse Determined by the ChronAIco I.D.™-Assay

“…Surprisingly, the cut-off values for the absolute CDT concentration, which is optionally available by the ChronAIco I.D.™-assay, was similar between women and men in our study. This is in contrast to the literature on CDTect assays, which reports higher CDT concentrations for women [2,8,12,13]. One reason for this observation could be the different recovery of the CDT-transferrins by the CDTect- [14] and the ChronAIco I.D.™-assay (Hackler et al, in preparation).…”

“…Although both tests have been used most frequently for determination of CDT, the production of the CDTect-EIA was terminated in January 1999. Thus, the laboratory has the choice of returning to the radioactive CDTect-RIA (which shows a good comparability with the CDTect-EIA [2]) or using a test incorporating (parts of) trisialotransferrin into the determination of CDT. However, whether trisialotransferrins occur with high prevalence in increased concentrations after chronic alcohol abuse and whether the incorporation of these transferrin isoforms improves the diagnostic performance of CDT is discussed controversially [3][4][5].…”

Comparison of transferrin isoform analysis by capillary electrophoresis and HPLC for screening congenital disorders of glycosylation

“…Transferrin, an abundant glycoprotein exhibits microhetrogeneity because of variable sialic acid residues attached to its glycan chains . Among the various isoforms, tetrasialotransferrin is the most predominant isoform followed by penta, tri, and disialotransferrin.…”

Kohlenhydrat-defizientes Transferrin (CDT): die derzeit spezifischste Kenngröße chronischen Alkoholmißbrauchs

“…Im Vergleich zu prämenopausalen Frauen zeigten östrogensubstituierte Frauen in der Menopause geringfügig erhöhte CDT-Konzentrationen (17,5 vs. 19,3 U/l). Da die Unpräzision der CDT-Bestimmung jedoch etwa 10% beträgt [35,36], dürfte diese Beobachtung für die tägliche Praxis von untergeordneter Bedeutung sein. Ein Anstieg der Serum-CDT-Konzentration mit der Schwangerschaftsdauer wurde in [50,51] beobachtet.…”