In 1996 (1) we described our first experience with the Axis % CDT RIA (Axis Biochemicals, ASA, Oslo) kit measuring the percentage of carbohydrate-deficient transferrin (CDT) as a marker of alcohol abuse. The manufacturer stopped the production of the RIA version in December 1997 and since then only the non-isotopic version Axis % CDT TIA is supplied. In the new version CDT eluted after anion exchange, as well as total transferrin present in the same serum sample, are measured by a turbidimetric immunoassay and % CDT is calculated from these two values. This improves its diagnostic value. Axis % CDT TIA is introduced as a second-generation test also because of its additional benefits such as versatile automation and lower cost. We present the evaluation of the Axis % CDT TIA as a manual microplate procedure with a computerized end-step measurement and calculation using our own software. The main goal of the study is a proof of commutability of the RIA and TIA versions in various clinical settings.

        Key words: carbohydrate-deficient transferrin, CDT, diagnostic marker of alcohol abuse, Axis % CDT RIA and Axis % CDT TIA, comparison of methods, reference ranges, diagnostic value.