New insights for identification of doping with recombinant human erythropoietin micro-doses after high hydration.

To minimize the chances of being caught after doping with recombinant human erythropoietins (rhEPO), athletes have turned to new practices using micro-doses and excess fluid ingestion to accelerate elimination and decrease the probability of detection. Our objective was to test the sensitivity of detection by validated methods (IEF: isoelectric focusing; SDS-PAGE: sodium dodecyl sulfate polyacrylamide gel electrophoresis) when such practices are used. First, after a three-week rhEPO boost period and 10 days of wash out, detection of a single 900 IU micro-dose of Eprex® was evaluated in healthy male subjects. After an injection in the evening, urine and plasma samples were collected the following morning. Half of the subjects then drank a bolus of water and new samples were collected 80 min later. Interestingly, rhEPO was detected in 100% of the samples even after water ingestion. A second similar protocol was then performed with a single injection of a micro-dose of rhEPO (500 IU or 900 IU), without a prior rhEPO boost. In addition, urine and plasma samples were also collected 15 and 20 h post rhEPO administration. Once again drinking water did not affect the rate of detection. Urine appeared a better matrix to detect micro-doses after 10 h, enabling between 92% and 100% of identification at that time. The rate of identification decreased rapidly thereafter, in particular for the 500 IU micro-dose. However IEF analysis still resulted in 71% identification of rhEPO in urine after 20 h. These results could help to define a better strategy for controlling and identifying athletes using rhEPO micro-doses. Copyright © 2016 John Wiley & Sons, Ltd.