Asialotransferrin--an alternative to carbohydrate-deficient transferrin?

Abstract

Asialotransferrin, monosialotransferrin, and disialotransferrin are collectively referred to as carbohydrate-deficient transferrin (CDT) (1)(2). Over the last several years, the definition of CDT has become increasingly vague (which transferrin isoforms are CDT isoforms and which are not). Thus, different transferrin isoforms are analyzed with various recoveries as CDT (2). The lack of standardization of CDT analysis complicates the preanalysis, analysis, and interpretation of CDT. To overcome this problem, consistent use of the CDT definition introduced by Stibler (1), a redefinition of CDT, or replacement by a clearly defined analyte is needed (2). In our laboratory, using isoelectric focusing for transferrin isoform analysis (3)(4)(5), we observed a high prevalence of bands for asialotransferrin and monosialotransferrin, plus an increased fraction of disialotransferrin, in serum samples with increased CDT. In contrast, samples from healthy persons (with typical alcohol intake and CDT values within the reference interval) usually did not show asialo- and monosialotransferrin bands. Similar observations have been reported by others (1)(2). This prompted the suggestion to replace the analyte group CDT by asialotransferrin as a clearly defined analyte (6). However, there has not been a sufficiently sensitive and quantitative analytical method available to investigate the value of asialotransferrin as a marker of chronic alcohol abuse. …