Transferrin phenotype and level of carbohydrate-deficient transferrin in healthy individuals.

Elevated concentrations of carbohydrate-deficient components of transferrin (CDT) in serum may be used as a sensitive and specific marker of regular, high alcohol consumption. When determined by a new, simplified assay, CDT values are nearly normally distributed in low- or non-alcohol-consuming control populations. The importance of transferrin phenotype for this normal variation was analyzed in 100 healthy, European men and women with no or negligible alcohol intake. No significant relation was found between phenotype and CDT value in this population. The three rare B-variants found had low CDT levels, and one subject, examined outside the study, with a rare D-variant indicated that D-variants may result in false-positive CDT values. Moreover, women tended to have somewhat higher values than men, in whom CDT levels were weakly correlated with age. Other as yet undefined biological factors are clearly responsible for the major part of the normal variation of CDT values in nonalcoholic individuals.