HPLC analysis of carbohydrate deficient transferrin isoforms isolated by the Axis-Shield %CDT method.

Background: Carbohydrate-deficient transferrin (CDT) is elevated during prolonged overconsumption of alcohol and CDT is considered to be the most specific biochemical marker for alcohol overconsumption. However, an accurate method for analysing CDT is necessary because the test is frequently used for example in legal matters.

Methods: Patient serum samples were analysed with the Axis-Shield %CDT and eluates were pooled together. Transferrin was purified from the pool by affinity chromatography and further analysed with HPLC to determine the ratios of different transferrin isoforms.

Results: In the eluates using the Axis-Shield %CDT method, a substantial amount of trisialo transferrin was found, which is generally not considered a CDT isoform.

Conclusions: The fact that trisialo transferrin is present may generate falsely elevated CDT results and it could at least partly explain the discrepancy between results of the Axis-Shield %CDT assay and HPLC in routine analysis.