Search

This article traces the historical development of various biomarkers of acute and/or chronic alcohol consumption. Much of the research in this domain of clinical and laboratory medicine arose from clinics and laboratories in Sweden, as exemplified by carbohydrate deficient transferrin (CDT) and phosphatidylethanol (PEth). Extensive studies of other alcohol biomarkers, such as ethyl glucuronide (EtG), ethyl sulfate (EtS), and 5‐hydroxytryptophol (5‐HTOL), also derive from Sweden. The most obvious test of recent drinking is identification of ethanol in a sample of the person's blood, breath, or urine. However, because of continuous metabolism in the liver, ethanol is eliminated from the blood at a rate of 0.15 g/L/h (range 0.1–0.3 g/L/h), so obtaining positive results is not always possible. The widow of detection is increased by analysis of ethanol's non‐oxidative metabolites (EtG and EtS), which are more slowly eliminated from the bloodstream. Likewise, an elevated ratio of serotonin metabolites in urine (5‐HTOL/5‐HIAA) can help to disclose recent drinking after ethanol is no longer measurable in body fluids. A highly specific biomarker of hazardous drinking is CDT, a serum glycoprotein (transferrin), with a deficiency in its N‐linked glycosylation. Another widely acclaimed biomarker is PEth, an abnormal phospholipid synthesized in cell membranes when people drink excessively, having a long elimination half‐life (median ~6 days) during abstinence. Research on the subject of alcohol biomarkers has increased appreciably and is now an important area of drug testing and analysis. [ABSTRACT FROM AUTHOR]

Pathogenic variants in ALG13 (ALG13 UDP‐N‐acetylglucosaminyltransferase subunit) cause an X‐linked congenital disorder of glycosylation (ALG13‐CDG) where individuals have variable clinical phenotypes that include developmental delay, intellectual disability, infantile spasms, and epileptic encephalopathy. Girls with a recurrent de novo c.3013C>T; p.(Asn107Ser) variant have normal transferrin glycosylation. Using a highly sensitive, semi‐quantitative flow injection‐electrospray ionization‐quadrupole time‐of‐flight mass spectrometry (ESI‐QTOF/MS) N‐glycan assay, we report subtle abnormalities in N‐glycans that normally account for <0.3% of the total plasma glycans that may increase up to 0.5% in females with the p.(Asn107Ser) variant. Among our 11 unrelated ALG13‐CDG individuals, one male had abnormal serum transferrin glycosylation. We describe seven previously unreported subjects including three novel variants in ALG13 and report a milder neurodevelopmental course. We also summarize the molecular, biochemical, and clinical data for the 53 previously reported ALG13‐CDG individuals. We provide evidence that ALG13 pathogenic variants may mildly alter N‐linked protein glycosylation in both female and male subjects, but the underlying mechanism remains unclear. [ABSTRACT FROM AUTHOR]

Background: Estimates of the performance of carbohydrate deficient transferrin (CDT) and gamma glutamyltransferase (GGT) as markers of alcohol consumption have varied widely. Studies have differed in design and subject characteristics. The WHO/ISBRA Collaborative Study allows assessment and comparison of CDT, GGT, and aspartate aminotransferase (AST) as markers of drinking in a large, well-characterized, multicenter sample. Methods: A total of 1863 subjects were recruited from five countries (Australia, Brazil, Canada, Finland, and Japan). Recruitment was stratified by alcohol use, age, and sex. Demographic characteristics, alcohol consumption, and presence of ICD-10 dependence were recorded using an interview schedule based on the AUDADIS. CDT was assayed using CDTect™ and GGT and AST by standard methods. Statistical techniques included receiver operating characteristic (ROC) analysis. Multiple regression was used to measure the impact of factors other than alcohol on test performance. Results: CDT and GGT had comparable performance on ROC analysis, with AST performing slightly less well. CDT was a slightly but significantly better marker of high-risk consumption in men. All were more effective for detection of high-risk rather than intermediate-risk drinking. CDT and GGT levels were influenced by body mass index, sex, age, and smoking status. Conclusions: CDT was little better than GGT in detecting high- or intermediate-risk alcohol consumption in this large, multicenter, predominantly community-based sample. As the two tests are relatively independent of each other, their combination is likely to provide better performance than either test alone. Test interpretation should take account sex, age, and body mass index. [ABSTRACT FROM AUTHOR]

Background: Carbohydrate deficient transferrin (CDT), a biochemical marker of chronic alcohol consumption, is used by researchers and clinicians alike in a variety of populations. Levels of CDT may be affected by certain types of medical illnesses and conditions. Thus the interpretation of CDT results may need to be carefully examined in these populations. Because CDT is synthesized, glycosylated, and secreted by the liver, the use of CDT values in patients with liver disease has been an area of focused interest. Methods: We evaluated the CDT values of 79 abstaining patients with end-stage liver disease. These patients were recruited from a liver transplant clinic while they were listed and waiting for transplantation. Patients were determined to be abstaining both by interview and by random blood alcohol levels in those with a diagnosis of alcoholic liver disease. The severity of the liver disease was categorized by the Child-Pugh score. Correlations were determined between CDT values and liver enzymes, and Child-Pugh scores and liver diagnosis. Results: Nearly 50% of the patients had a CDT value of 2.6% or above, indicating a clinically positive value. There were strong correlations between CDT and a number of biochemical and physical variables, most importantly the Child-Pugh score ( r= 0.52, p= 0.000). Specific liver diseases were not associated with absolute CDT values. However, patients with hepatitis C (HCV) had a significantly higher chance of having a clinically positive CDT compared with patients with other types of liver diseases. Conclusions: These results suggest that an elevated CDT value may not accurately represent alcohol consumption in patients with advanced liver disease. In fact, in such patients, the CDT may become a marker for the degree of liver impairment in alcoholic and nonalcoholic liver disease. CDT values should be viewed with caution in any patient with liver disease especially when the degree of cirrhosis reaches a Child-Pugh score of C (total score of 10 or above). [ABSTRACT FROM AUTHOR]

Eight previous investigations have suggested that conjoint consideration of findings on tests for gamma glutamyl transpeptidase (GGT) and carbohydrate deficient transferrin (CDT) substantially enhances sensitivity of screening for alcohol problems while minimally diminishing specificity. Using results from a large clinical trial, the current study evaluated the two tests singly and in combination as measures of three clinically important treatment outcome criteria: any drinking, at least one day of heavy drinking, and at least three consecutive days of heavy drinking during the past month. When scored by quartile, CDT is slightly better at screening for alcohol problems in males than GGT. However, CDT seems less accurate in females than GGT. Use of the two tests in consort moderately improves the individual test accuracy in predicting drinking status for both genders. [ABSTRACT FROM AUTHOR]

We meesured serum levels of carbohydrate deficient transferrin (CDT) in 420 subjects: 100 healthy blood donors, 82 healthy employses, 70 abstaining patients with different chronic nonalcoholic liver disease, 16 abstaining patients with alcoholic fatty liver, 50 abstaining patients with alcohotic liver cirrhosls, 25 abusing patients with alcoholic fatty liver, 41 abusing patients with alcoholic liver cirrhosis, and 36 patients with alcohol dependence syndrome with a daily ethanol consumption of 173 ± 120 g the last 4 weeks before blood was drawn. In controls the serum level of CDT was significantly higher in females compared with males (17.7 ± 5.1 and 13.7 ± 3.8 units/liter, respectively), and the upper normal limit was defined as 27 and 20 units/liter. Sixty-two of 102 (60.8%) abusing patients with alcoholic liver disease had increased levels of CDT compared with 1 of 66 abstaining (1.5%) patients with alcoholic liver disease, and 10 of 70 (14.3%) abstaining patients with nonalcoholic liver disease among them 3 with primary biliary cirrhosis and 2 with chronic autoimmune hepatitis. No correlation was found between serum CDT and γ-glutamyltranspeptidase (GGT), AST, ALT, and mean red cell volume (MCV). The sensitivity and specificity for serum CDT was 61 and 92%, respectively, compared with 85 and 18% for GGT and 70 and 66% for MCV. No advantage was gained by using the CDT/transferrin ratio. Our study confirms that CDT is a specific marker for chronic alcohol abuse, except in few patients with other chronic liver diseases. Serum CDT seems to be a better indicator of abstention than GGT; AST and MCV in patients with alcoholic liver disease. However, in our hands CDT is not so sensitive for alcohol abuse in patients with liver disease as reported earlier in unselected alcoholics [ABSTRACT FROM AUTHOR]