Determination of carbohydrate deficient transferrin (CDT) with capillary electrophoresis: an inter laboratory comparison

Carbohydrate deficient transferrin (CDT) is currently the most specific laboratory marker of chronic or sustained alcohol abuse. CDT is increasingly being used as a diagnostic tool in the areas employment, traffic safety and forensic medicine. In recent times, capillary electrophoresis (CE) has been proposed as a convenient tool for rapid, precise and accurate CDT determination, not only for research but also for routine analyses. Quite recently, commercial kits have been introduced which, reportedly, could simplify and standardize CDT analysis with capillary electrophoresis. The present work was aimed at testing the ruggedness of a capillary electrophoretic method based on a commercial kit (CEofix, Analis), by comparing the results obtained with different instruments in different laboratories, on a panel of sera randomly collected and exchanged. The results showed, notwithstanding few outliers, excellent correlation of the results obtained in the two laboratories (R=0.974). Also high concordance was found when results were classified as positive or negative on the basis of a cut-off (1.25%) established from a control group of teetotalers. In conclusion the present data support the usefulness of capillary electrophoresis for CDT determination for clinical, forensic and administrative diagnosis of chronic alcohol abuse.