Carbohydrate-deficient transferrin, a sensitive marker of chronic alcohol abuse, is highly influenced by body iron

Abstract

Carbohydrate-deficient transferrin (CDT), a microheterogeneous form of serum transferrin (Tf), has been proposed as the most reliable marker of chronic alcohol consumption, although unexplained false-positive and -negative results have been reported. We investigated whether body iron influenced CDT serum levels by studying alcohol abusers with or without iron overload and nonabusers with iron deficiency or iron overload caused by genetic hemochromatosis (GH). In alcohol abusers, CDT was significantly lower in the presence of iron overload than in the absence (24.6 ؎ 16.5 U/L vs. 33.3 ؎ 11.7 U/L; P F .01), with false-negative results almost exclusively in patients with iron overload. Similarly, in nonabusers with GH, CDT was lower than in normal controls (9.6 ؎ 2.2 U/L vs. 15.7 ؎ 3.3 U/L; P F .0001), whereas, patients with iron deficiency anemia had significantly higher levels than controls (28.1 ؎ 5.8 U/L vs. 15.7 ؎ 3.3 U/L; P F .0001). In nonabusers, iron supplementation therapy significantly decreased CDT levels in patients with iron deficiency anemia (33.7 ؎ 6.6 U/L vs. 21.7 ؎ 5.2 U/L; P ‫؍‬ .0007), while iron-depletion treatment significantly increased CDT levels in patients with GH (9.7 ؎ 2.0 U/L vs. 14.7 ؎ 4.0 U/L; P ‫؍‬ .001). Alcohol abusers had a significant relationship between liver iron concentration (LIC) and the reciprocal of CDT (r ‫؍‬ .65; P F .0001), while in nonabusers, there was a significant correlation between Tf and CDT (r ‫؍‬ .72; P F .0001). In conclusion, CDT serum levels are markedly affected by the patient's iron status, with iron overload reducing its sensitivity in alcohol abusers and iron deficiency its specificity in nonabusers. CDT can be considered a reliable marker of alcohol abuse only when iron stores are normal. (HEPATOL-OGY 1999;29:658-663.)

Carbohydrate Deficient Transferrin in Abstaining Patients With End‐Stage Liver Disease

“…However, while the degree of liver fibrosis did not correlate with elevated CDT levels, in that study few patients had advanced liver disease (cirrhosis) and only 10% were clinically affected by their liver disease (Stibler, 1987). In contrast, investigations of other specific populations have reported a high degree of variability in CDT depending on body iron (DeFeo et al, 1999), gender and exogenous estrogens (Stauber et al, 1996), and specific types of liver diseases (Bell et al, 1993;Murawaki et al, 1997;Stauber et al, 1995). For example, Heinemann found an unacceptable specificity rate (as low as 20 -50%) resulting in a high rate of false positives in patients with severe liver disease awaiting liver transplantation (Heinemann et al, 1998).…”

Possible Reasons Why Heavy Drinking Increases Carbohydrate‐Deficient Transferrin

“…Because the primary function of transferrin in the body is iron transport, factors that affect iron balance also alter CDT values in serum (De Feo et al, 1999;De Jong et al, 1992). Several studies of iron homeostasis seem to indicate that changes in CDT levels may modulate internal iron fluxes between sites of storage and utilization to balance tissue demands.…”

“…Stauber et al (1996b) could not confirm the correlation with serum iron reported by Anton and Moak (1994) among women. However, in an important recent article, De Feo et al (1999) demonstrated that serum CDT levels are affected markedly by iron status. Subjects with iron overload had reduced CDT values (Ϫ26% among alcohol abusers and Ϫ39% among nonabusers), whereas CDT was increased (79%) in subjects who had iron deficiency.…”

Study of the feasibility of using a pellicular anion-exchange column for separation of transferrin isoforms in human serum by HPLC with UV detection

“…A decrease in sialylation has been observed in individuals with congenital disorders of glycosylation [10], biliary cirrhosis [11], cystic fibrosis [12], hypertension [13], iron deficiency and anaemia [14,15], haemocromatosis [16], and alcoholism [17,18,19,20,21].…”