Determination of Carbohydrate-deficient Transferrin Levels by Using Capillary Electrophoresis in a Korean Population

Abstract

Carbohydrate-deficient transferrin (CDT) is reported to be an accurate biomarker for the detection of chronic alcohol abuse and for monitoring abstinence [1,2]. Transferrin (Tf) is the most important iron transport protein.Tf is synthesized primarily in the hepatocytes and consists of 3 substructural domains. These domains include a single polypeptide chain, 2 independent metal ionbinding sites, and 2 N-linked complex glycan chains [2].Tf exists in several glycoforms, which differ in the degree of branching of the N-linked glycan chains. The glycan chains have bi, tri, and tetraantennary structures [2,3].The primary Tf isoform is tetrasialo-Tf (64-80%). Other less abundant isoforms found in nonpathologic conditions include pentasialo-Tf, trisialo-Tf, and disialo-Tf Background: Carbohydrate-deficient transferrin (CDT) levels have rarely been determined in an Asian population. We evaluated the analytical performance of a test for measuring CDT levels by using capillary electrophoresis (EP).Methods: We determined the precision of CDT measurement by using capillary EP and nephelometry and compared the CDT values obtained using both the methods. We included healthy control subjects, abstinent patients with liver disease, and individuals consuming varying amounts of alcohol.Results: The CDT measurement by using capillary EP were correlated well with those CDT measurement by using nephelometry, N Latex CDT assay, Y=0.5706X+1.581, R=0.930. The results obtained from both methods showed good qualitative agreement with each other (k coefficient=0.61). Genetic variants of transferrin isoforms were detected in 4.1% of the tested population. Both the CDT and g -glutamyl transpeptidase (GGT) levels in the abstinent patients with liver disease were significantly higher than those in healthy abstinent individuals (0.9% vs. 0.5%, 109.5 mg/dL vs. 28.5 mg/dL, respectively), but the difference in CDT values in the 2 groups was less pronounced for the CDT values. Individuals who had a mean daily alcohol intake of more than 60 g/day showed significantly higher CDT levels than those who had a mean daily alcohol intake of less than 60 g/day (1.9% vs. 0.7%, P=0.03).Conclusions: The CDT test using capillary EP showed good performance, and this method has several advantages such as automation and detection of variant forms. Thus, CDT can be a more useful marker than GGT for monitoring alcohol abstinence, especially in patients with liver disease. (Korean J Lab Med 2010;30:477-84)

Biomolecules and Biomarkers Used in Diagnosis of Alcohol Drinking and in Monitoring Therapeutic Interventions

“…Furthermore, CDT levels were higher in individuals consuming >60 g alcohol/day than those consuming <60 g alcohol/day ( p = 0.034). CDT levels were slightly lower when assessed by capillary electrophoresis, but a good correlation was found between this method and nephelometry [ 238 ]. Hepatitis C virus seropositivity is associated with significantly decreased baseline CDT levels in patients undergoing treatment for alcohol dependence [ 239 ].…”

Determination of carbohydrate-deficient transferrin in a Han Chinese population

“…These differences may be due to the measurement systems (high-performance liquid chromatography [HPLC], vs. capillary electrophoresis) and target subjects (Western vs. Asian populations). Many factors influence CDT values, including atypical phenotype distributions of alcohol dehydrogenase [14], amount of daily alcohol consumption, amount of alcohol consumed per drinking session, duration of abstinence before blood sampling, body weight [15] and consumption of fermented food. All these factors may contribute to the CDT differences between Han Chinese and other populations.…”

Monitoring of transferrin isoforms in biological samples by capillary electrophoresis

“…The cutoff used for the Helena V8 assay is 1.60% [86] whereas the cutoff values for the CEofix assays and the Verona assay are 1.8 or 1.7% [4,81,82,85]. Overall, there is high correlation between data obtained by the different CZE assays and for the comparison of CZE data to those obtained by HPLC [30, 42,87,107,[109][110][111][113][114][115][116][117][118][119][120][121][122][123][124][125]. A detailed comparison of most of these data is given in [4].…”