N Latex CDT AssayHighly specific screening for detection of chronic alcohol abuse

The N Latex CDT assay for use on Atellica® NEPH 630, BN™ II and BN ProSpec® Systems provides a highly specific screening method for the detection of alcohol abuse. The CDT level increases and decreases with the amount of alcohol consumed; therefore, many different applications are possible, such as differential diagnosis of alcohol-induced versus nonalcohol-induced diseases, legal applications (e.g., for regranting of driver’s license), workplace testing, or forensic toxicology.

  • Fully automated immunoassay with no sample pretreatment required
  • Highly specific monoclonal antibody that directly detects CDT
  • Automatic calculation of %CDT by running CDT and transferrin assays simultaneously
  • Fast availability of results—within 20 minutes (total assay time)
  • Random-access capability
  • Reliable results—excellent recovery between labs, systems, and lots

Features & Benefits

Carbohydrate-deficient transferrin (CDT) is regarded as a very specific marker for identifying excessive alcohol consumption and monitoring abstinence during outpatient treatment.

Regular alcohol consumption of more than 50–80 g of ethanol per day for at least 2 weeks can result in a changed glycosylation pattern of transferrin, leading to a higher rate of isoforms lacking one or both entire carbohydrate chains. These isoforms (disialo- and asialotransferrin) are collectively named carbohydrate-deficient transferrin (Figure 1). After approximately 2–4 weeks of abstinence, CDT concentrations usually return to normal levels.

CDT Marker

Compared to other markers, CDT offers superior sensitivity and specificity:1,2

  • CDT is seemingly unaffected by liver diseases other than those induced by alcohol abuse (except biliary cirrhosis and chronic active hepatitis).
  • CDT is not influenced by common chronic diseases or medication.
  • CDT indicates the effectiveness of alcohol detoxification much earlier than gamma-glutamyl transferase or erythrocyte mean corpuscular volume, for example.

Based on an assumed cutoff of 2.5 %CDT, test results obtained with N Latex CDT on BN™ Systems exhibit a specificity of 97% and a sensitivity of 93% in comparison to the %CDT values determined with HPLC.3

Technical Specifications

Assay principle

Latex-enhanced immunonephelometry

Sample type

Human serum

Measuring time

18 minutes

Reference range

28.1–76 mg/L (1.19–2.47% CDT)4

Initial measuring range

20–660 mg/L

Once-opened reagent stability

2 weeks on Atellica NEPH 630 and BN ProSpec® Systems
3 days (6 days with evaporation stoppers) on BN™ II System

Calibration frequency

2 weeks


Repeatability: <4.5%
Within-lab: <2.0%