Influence of iron saturation as a possible source of error in the immunoturbidimetric determination of serum transferrin

1982 ◽  
Vol 121 (1) ◽  
pp. 117-122 ◽  
Author(s):  
Johannes A.G. Klein Gebbink ◽  
Johannes O.O. Hoeke ◽  
Joannes J.M. Marx
Keyword(s):  
Serum Transferrin ◽  
Iron Saturation ◽  
Source Of Error

scholarly journals Nephelometric determination of carbohydrate deficient transferrin

1996 ◽  
Vol 42 (4) ◽  
pp. 551-557 ◽  
Author(s):  
F Schellenberg ◽  
M Martin ◽  
E Cacès ◽  
J Y Bénard ◽  
J Weill
Keyword(s):  
Sialic Acid ◽  
Characteristic Curve ◽  
Anion Exchange Chromatography ◽  
Receiver Operator Characteristic Curve ◽  
Exchange Chromatography ◽  
Treatment Center ◽  
Serum Transferrin ◽  
Receiver Operator Characteristic ◽  
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).

scholarly journals Quantification of carbohydrate-deficient transferrin by ion-exchange chromatography with an enzymatically prepared calibrator

1997 ◽  
Vol 43 (3) ◽  
pp. 485-490 ◽  
Author(s):  
Florian Renner ◽  
Rolf-Dieter Kanitz
Keyword(s):  
Hplc Method ◽  
Ion Exchange Chromatography ◽  
Exchange Chromatography ◽  
Reference Ranges ◽  
Diagnostic Specificity ◽  
Time Saving ◽  
Iron Saturation ◽  
Carbohydrate Deficient Transferrin ◽  
Absolute Concentrations

Abstract The current HPLC method for the determination of carbohydrate-deficient transferrin (CDT) yields ratios of CDT isoforms in relation to total transferrin, whereas the use of absolute concentrations obtainable in routine analysis by RIA and the reference ranges based hereupon is more convenient. We describe a modified HPLC method that likewise gives absolute CDT concentrations by using a calibrator prepared by treatment of transferrin with neuraminidase. Separation of isoforms could be improved and analysis time reduced to ∼2 h. Iron saturation proved stable during chromatography. In contrast to a commercial RIA, the cheaper and more time-saving HPLC method excludes erroneous results caused by aged samples or genetic transferrin variants and enables the determination of asialo- and disialotransferrin. Both methods showed comparable precision and correlated with each other (y = 1.76 + 0.27x; Sy|x = 5.38); for the HPLC method precision was 1.3–9.8% (within assay) and 6.2–10.6% (between assay). The clinical evaluation with a cutoff concentration of 80 mg/L resulted in a diagnostic specificity of 100% and a sensitivity of 82.5%.

scholarly journals Validation by isoelectric focusing of the anion-exchange isotransferrin fractionation step involved in determination of carbohydrate-deficient transferrin by the CDTect assay

1998 ◽  
Vol 44 (1) ◽  
pp. 27-34 ◽  
Author(s):  
Torsten Arndt ◽  
Rolf Hackler ◽  
Tilman O Kleine ◽  
Axel M Gressner
Keyword(s):  
Isoelectric Focusing ◽  
Laboratory Diagnosis ◽  
Good Precision ◽  
Chronic Alcohol Abuse ◽  
Negative Results ◽  
Iron Saturation ◽  
Low Concentrations ◽  
Carbohydrate Deficient Transferrin

Abstract Serum concentration of carbohydrate-deficient transferrin (CDT) is used for laboratory diagnosis of chronic alcohol abuse. Using isoelectric focusing for validation of the initial isotransferrin fractionation step involved in the determination of CDT by the CDTect assay, we found a complete in vitro iron saturation of transferrin and sufficient stability of the transferrin iron load during column passage; effective separation of non-CDT-isotransferrins and CDT-isotransferrins at the microcolumns; partial coelution of trisialo-Fe2-transferrin, which did not significantly affect CDT measurement; partial retention of CDT-isotransferrins, especially disialo-Fe2-transferrin, which may cause falsely negative results for CDT at the upper reference limits; good precision of the isotransferrin fractionation step; and no significant effects of low concentrations of serum protein and transferrin. We strongly urge standardization of CDT analysis and suggest isoelectric focusing for validation of CDT analysis methods and verification of odd results.

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