Multicentre validation study of instrument applications for %CDT, an immunoassay for quantification of carbohydrate-deficient transferrin in serum

This multicentre trial assessed the inter-laboratory transferability and agreement of results for five instrument applications (Immage, BN A, BN II, Cobas Mira and Microtiter) of the Axis-Shield %CDT kit, a new version immunoassay for quantification of the alcohol marker carbohydrate-deficient transferrin (CDT) in serum. Two %CDT kit controls and three authentic serum samples were compared by 14 laboratories in six European countries, and each application was evaluated at three study sites. The %CDT results showed an overall good agreement both within and between sites, although it was also demonstrated that the analysis might be biased due to site performance. The data indicate that transferability of the %CDT assay is high, and that the instrument applications may be used interchangeably in routine quantification of %CDT.