Carbohydrate-deficient transferrin measured by high-performance liquid chromatography and CDTect immunoassay

Carbohydrate-deficient transferrin (CDT) was measured in three populations using anion-exchange chromatography followed by radioimmunoassay (CDTectTM) and a new high-performance liquid chromatography (HPLC) method. The correlation between the methods in 50 consecutive clinical samples was good (r = 0.87). However, in a set of 49 samples with CDT concentrations close to the reference value of the methods, the correlation was low (r = 0.51). In addition, among controls, no correlation between the methods was found (r = 0.10). Abnormal isoforms of transferrin were noted in 5% of the clinical samples. HPLC determination of CDT offers the advantage of identifying these isoforms of transferrin and thus reducing analytical pitfalls associated with the CDTectTM method.