|
CARBOHYDRATE-DEFICIENT TRANSFERRIN AND CHRONIC ALCOHOL ABUSE
D'Ottavi A.*, Caracciolo F.**
* Laboratorio Tossicologia Clinica - Vecchio Ospedale - AUSL Ascoli Piceno - Italia
** Servizio Patologia Clinica P. O. "Spirito Santo" - Pescara - Italia
Human transferrin (MW 80,000 Da) is an iron-transporting protein in plasma. It is synthesized in liver as a monomeric glycoprotein containing two N-linked oligosaccharide chains. Human transferrin occurs in isoforms with different levels of sialylation: it has been found that in serum of individuals with elevated alcohol intake, the carbohydrate-deficient isoforms occur in elevated levels. The sum of carbohydrate-deficient isoforms (referred as CDT: Carbohydrate-Deficient Transferrin) is an highly sensitive and specific marker for detection and monitoring of alcohol abuse.
The aim of our study was to compare two commercial methods for screening of CDT in human serum using an ion exchange HPLC as confirmatory method.
This study included 63 males and 10 females admitted to a alcoholics detoxification centre, with well-documented drinking habits.
Methods. Comparisons were made between...
- Axis %CDT: is a heterogeneus immunoassay with column separation followed by turbidimetric measurement of total transferrin content of sample and eluted CDT isoforms determinated separately using the same antibodies. The measurements were performed using a calibration curve by Roche Cobas Mira Plus (automatic turbidimetry analyser).The results were expressed as % CDT values of total transferrin.
- Pharmacia CDTect EIA: is a competitive enzyme immunoassay with column separation. Eluted CDT was measured by colorimetric-enzymatic reaction on microplate reader BRIO (Basic Radim Immunoassay Operator). The results were expressed using a calibration curve in CDT U/l.
Confirmatoty method: HPLC separation was performed with a Hewlett Packard HPLC 1050 system, using a strong anionic exchange chromatography column (Pharmacia Mono Q HR 5/5); detection was done at 160 nm. Each transferrin isoform was expressed as % of total transferrin area.
Analytical variability and correlation of the methods employed will be presented.
In conclusion, the HPLC and the Axis % CDT techniques offers advantages in comparison with CDTect EIA ones, expecially as they can avoid incorrect estimations of CDT depending on individual abnormal values of total serum transferrin.
|
