Erythropoietin Abuse in Sport

• Erythropoietin Abuse in Sport

AUTHOR(S)

Neil ROBINSON, Patrice MANGIN, and Martial SAUGY

Laboratoire Suisse d'Analyse du Dopage, Institut Universitäire de Médecine Légale

SUMMARY

In a sporting context ‘doping' refers to the use by athletes of banned substances for the purpose of enhancing physical performance. The word ‘dope' originated in the African continent and referred to a primitive alcoholic drink that was used as a stimulant in ceremonial dances. The term ‘blood doping' was introduced in the 1970s to describe the use of blood transfusion ( homologous or autologous ) to increase the red cell mass artificially and so enhance both maximal oxygen uptake and performance in endurance sports, particularly in international cycling and cross-country skiing. Since the late 1980s blood doping is no longer only achieved by autologous transfusion but by the administration of recombinant human erythropoietin ( rHuEpo ) and more recently still the use of Haemoglobin-Based Oxygen Carriers ( HBOCs ) and other oxygen transport molecules. The International Olympic Committee and other major sporting bodies officially prohibit the use of rHuEpo. The International Ski Federation ( FIS ) was the first organisation to introduce haemoglobin ( Hgb ) limits to allow participation. The idea was to limit both the degree of health risk ( hyperviscosity, thrombosis and hypertension ) and the degree of performance enhancement. This was followed by the introduction of haematocrit ( Hct ) limits by the International Cycling Union ( UCI ) and the International Biathlon Union ( IBU ). An editorial review of strategies for the prevention and detection of doping with rHuEpo was published in 2000.

Since 2000 it has been possible to identify recombinant EPO. The electrophoretic mobility technique provides a direct measurement of urine levels of rHuEpo, and is based on the principle that the rHuEpo molecule is less negatively charged than the endogenous EPO molecule. Isoelectric focusing has emerged recently as a method for the direct analysis of rHuEpo in urine. However, the concept of indirectly detecting rHuEpo or other EPO mimetic substances through their effect on other blood characteristics is promising. Some sports have already imposed upper thresholds on Hgb concentration and Hct. The disadvantages of using thresholds are many including natural inter-individual variation, effect of posture and ease of manipulation through interventions such as, for example, infusion of saline. Suitable indirect markers include the concentration and physical properties of erythrocytes and reticulocytes ( Ret ) and the serum concentration of soluble transferrin receptor ( sTfr ) either singly or in combination. Algorithms that combine scores from multiple blood parameters are demonstrably effective in highlighting long term continuous rHuEpo administration and have been used to deter its use by athletes.

KEY WORDS

Hematocrit, Reticulocyte, Cyclist, Doping, Blood