P. Bean, Carbohydrate-deficient transferrin in the assessment of harmful alcohol consumption: diagnostic performance and clinical significance, ADDICT BIOL, 4(2), 1999, pp. 151-161
The last decade saw the emergence of carbohydrate-deficient transferrin (CD
T) as the most promising marker for the diagnosis of alcohol abuse. Daily a
lcohol consumption of four beers, four glasses of wine or three standard dr
inks causes increased concentrations of CDT in serum. CDT is serum pz trans
ferrin with a reduced content of oligosaccharides due to the detrimental ef
fects of alcohol metabolism of? the glycosylation pathway, of hepatocytes a
nd/or the increased activity, of circulating glycosidases in serum. Most cu
rrent CDT procedure es entail separation of normal transferrin from CDT in
a charged matrix-like isoelectricfocusing and ion exchange chromatography,
followed by detection/quantitation of CDT by a myriad of immunoassays: immu
noblotting, radioimmunoassay, enzyme immunoassay and nephelometry. New CDT
procedures present the advantages of improved performance, inexpensive auto
mation and CDT results Expressed as a percentage of total serum transferrin
. CDT's major asset is its high specificity in well-defined populations i.e
. individuals ingesting 60g alcohol daily,for at least a week. The sensitiv
ity rates, which vary between 22% and 81%, depend on the amount of alcohol
ingested, time of sample collection after the cessation of drinking, age, g
ender and the cut-off point chosen for analysis of tests' results. Regardin
g clinical applications, best outcome is achieved when the test is used to
confirm a suspicion of alcohol abuse and when monitoring abstinence and rel
apses. The low prevalence of alcohol abuse in the general population challe
nges its use as a screening test. With the advent of inexpensive automation
and the constant emergence of innovative, improved tests, we are seeing th
e rise of a new era in alcohol abuse diagnosis as affordability and educati
on allows widespread use of CDT in a variety of settings.