Does Trisialo-Transferrin Provide Valuable Information for the Laboratory Diagnosis of Chronically Increased Alcohol Consumption by Determination of Carbohydrate-deficient Transferrin?

[摘要] Transferrin, the principal iron transporter in human serum, is a glycoprotein bearing asparagine-linked polysaccharides (1). Because of differences in the glycan structure, several transferrin isoforms can be found in normal serum, the most prominent one containing two biantennary complex-type glycans with a total number of four negatively charged terminal sialic acid residues (2)(3). It has been known for >20 years that chronically increased consumption of ethanol affects the glycosylation pattern of serum transferrin, producing a higher proportion of transferrin isoforms that lack terminal sialic acid residues and probably other parts of the glycan structure and thus are referred to as carbohydrate-deficient transferrin (CDT) (3)(4)(5). Originally, CDT was defined as the sum of transferrin isoforms containing two or fewer two sialic acid residues (corresponding to pI values ≥5.7), and this definition has likewise been applied to the evaluation of CDT as a sensitive and specific laboratory marker of alcoholism (4)(5). During the last few years, however, commercial kits were launched that measure an operationally defined CDT fraction that in addition to asialo-, monosialo-, and disialo-transferrin also includes at least in part the trisialo-transferrin isoform (6). The inclusion of trisialo-transferrin in the definition of CDT has been claimed to improve the detection of chronic alcohol consumption (7), but the diagnostic significance of the trisialo-transferrin concentration remains unclear (8). Therefore, I reexamined …

[学科分类] 过敏症与临床免疫学