The overall main goal of the IFCC WG-CDT to establish international standardisation of CDT analysis was not fully achieved to the extent that traceability of measurement results to the SI could not be established due to the assumption of identical molar extinction coefficients for all transferrin glycoforms; however, as the presented data show, this assumption is likely close to the truth. Nevertheless, the WG-CDT demonstrated that the different steps taken in this process, including defining the measurand (disialotransferrin to total transferrin fraction (%) in serum), selection of a well-defined HPLC candidate reference method allowing for relative quantification of the transferrin glycoforms, and organisation of an international laboratory network using the cRMP that assigns values to CDT calibrators based on frozen native human serum, contributes to the standardisation of CDT measurements.
The achieved standardisation and introduction of a common unique identifier for standardised CDT measurements (CDTIFCC) allows for direct comparison of values obtained by different routine measurement procedures, and use of a common reference interval. This will improve the diagnostic performance of CDT measurement as a biomarker of chronic heavy/excessive alcohol consumption, advance the ability to compare clinical and analytical trials on CDT, and last, but not least, improve patient care.