Novel comparison of capillary electrophoresis versus immunoassay in the measurement of total percent carbohydrate deficient transferrin

Objectives: Novel comparison of CDT isoforms as determined by CE with an FDA-approved immunoassay kit. Design and methods: Subjects (n = 51) were categorized by drinking status based on AUDIT questionnaire responses. CDT isoform analyses by CE were compared to a commercially available, FDA-approved immunoassay. The analytical specificity of the immunoassay kit was assessed by analysis with IEF. Results: Because of the poor correlation between % CDT as measured by CE and the TIA immunoassay and between subject-reported drinking levels and results from the TIA assay, extraction column eluants from the immunoassays were analyzed by IEF for analytical specificity. % CDT by TIA included some trisialo-Tf, a non-CDT fraction, in the % CDT determination. Conclusions: Total % CDT by CE, which separates all isoforms is more analytically specific than immunoassays because it does not include trisialo-Tf in the CDT calculation.