Testing for recombinant erythropoietin

Abstract

Erythropoietin (Epo) is a glycoprotein hormone that promotes the production of red blood cells. Recombinant human Epo (rhEpo) is illicitly used to improve performance in endurance sports. Doping in sports is discouraged by the screening of athletes for rhEpo. Both direct tests (indicating the presence of exogeneous Epo isoforms) and indirect tests (indicating hematological changes induced by exogenous Epo administration) can be used for Epo detection. At present, the test adopted by the World Anti Doping Agency is based on a combination of isoelectric focusing and double immunoblotting, and distinguishes between endogenous and rhEpo. However, the adopted monoclonal anti-Epo antibodies are not monospecific. Therefore, the test can occasionally lead to the false-positive detection of rhEpo (epoetin-beta) in post-exercise, protein-rich urine, or in case of contamination of the sample with microorganisms. An improved preanalytical care may counteract a lot of these problems. Adaptation of the criteria may be helpful to further refine direct Epo testing. Indirect tests have the disadvantage that they require blood instead of urine samples, but they can be applied to detect a broader range of performance improving techniques which are illicitly used in sports.