Increased concentrations of a transferrin variant after alcohol abuse.
Isoelectric focusing in agarose gel has been used for separation of different molecular forms of transferrin (Tf) in sera and plasma from alcoholics and controls. One special form of transferrin with isoelectric point 5.7 (= Tf5.7) was quantified by using zone immunoelectrophoresis assay (ZIA). This method was also used for quantification of total transferrin (Tftot). Significant differences in the ratio Tf5.7/Tftot between the groups were obtained and the diagnostic sensitivities, specificities and predictive values of positive tests were 100, 97, 93.8%, respectively. Thus the results showed that this principle seems to be much better for detection of alcoholic abuse than currently used assays as gamma-glutamyltransferase, etc. Samples taken on days following hospitalization showed that the Tf5.7 values decreased over a two-week period of abstinence. Possible explanations for the abnormal quotient after ethanol abuse are discussed.