Forensic analysis of carbohydrate-deficient transferrin (CDT) by HPLC--statistics and extreme CDT values.
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.
Arndt
Torsten
T
Bioscientia GmbH, Konrad Adenauer Strasse 17, D-55218 Ingelheim, Germany. torsten.arndt@bioscientia.de
Guessregen
Brunhilde
B
Hallermann
Dörte
D
Nauck
Markus
M
Terjung
Dirk
D
Weckesser
Holger
H
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
D015415:Biomarkers; D020033:Protein Isoforms; D014168:Transferrin; C056759:carbohydrate-deficient transferrin