title: Forensic analysis of carbohydrate-deficient transferrin (CDT) by HPLC--statistics and extreme CDT values.
abstract: BACKGROUND
  Carbohydrate-deficient transferrin (CDT) is the most specific serum marker of chronic alcohol abuse so far. There is little knowledge about extreme CDT values of >20% and the more >30% CDT.
  
  
  METHODS
  Serum CDT/transferrin ratios from 19,236 serum samples sent to our laboratory for routine CDT analysis were determined by HPLC. About 75% of these serum samples were from traffic or employment medicine investigations. A CDT value frequency histogram was computed and extreme CDT values were clinically validated.
  
  
  RESULTS
  Fourteen thousand four hundred and sixty-one CDT results were normal (< or =1.7%) and 4775 increased (1.8-36.9% CDT). Most frequent normal and increased results were 0.9% CDT (n=1964) and 1.8% CDT (n=356). CA. 70% of the pathological results were between 1.8% and 5.0% CDT, ca. 88% between 1.8% and 10.0% CDT, and 98% between 1.8% and 20.0%. CDT values >20.0% appeared in 79 cases and results >30.0% in two cases (33.8% and 36.9%). In each case of CDT values >20%, chronic alcohol abuse was the underlying cause as confirmed by anamnestic exploration.
  
  
  CONCLUSIONS
  CDT/transferrin ratios are usually <20%. Higher values can appear in rare cases. CDT results >30% can be due to alcohol abuse but should be considered as remarkable single observations. Visualization of the transferrin isoform patterns by HPLC allows the detection of pathological transferrin isoform patterns and of genetic transferrin variants. This is essential for a reliable interpretation of (extreme) CDT values. CDT analysis by immunoassays without physico-chemical confirmatory analysis is no longer acceptable.
authors.affiliation: Bioscientia GmbH, Konrad Adenauer Strasse 17, D-55218 Ingelheim, Germany. torsten.arndt@bioscientia.de
authors.forename: Torsten
authors.initials: T
authors.lastname: Arndt
authors.forename: Brunhilde
authors.initials: B
authors.lastname: Guessregen
authors.forename: Dörte
authors.initials: D
authors.lastname: Hallermann
authors.forename: Markus
authors.initials: M
authors.lastname: Nauck
authors.forename: Dirk
authors.initials: D
authors.lastname: Terjung
authors.forename: Holger
authors.initials: H
authors.lastname: Weckesser
mesh_terms: D000437:Alcoholism / Q000097:blood*; D015415:Biomarkers / Q000097:blood; D002851:Chromatography, High Pressure Liquid; D005260:Female; D053593:Forensic Toxicology; D006801:Humans; D008297:Male; D020033:Protein Isoforms; D012720:Severity of Illness Index; D014168:Transferrin / Q000031:analogs & derivatives* / Q000032:analysis
chemical_list: D015415:Biomarkers; D020033:Protein Isoforms; D014168:Transferrin; C056759:carbohydrate-deficient transferrin