Developing a Method to Protect the Integrity of Racing Using Targeted SRM: Detection and Quantitation of rhEPO/DPO in Horse Plasma

Introduction Recombinant human erythropoietin (rhEPO)2 and Darbepoetin-alpha (DPO)3 are genetically engineered protein-based drugs used for the treatment of anemia by stimulating red blood cell production. The ability of these agents to stimulate red blood cell production has led to use and abuse by human and equine athletes and, thus, violates the rule of fair competition resulting in their classification as banned substances by the horse racing industry. In addition, continued administration to horses can result in anemia.3 Despite the negative aspects of rhEPO for horses, a reliable, verifiable, and legally defensible method for identification and confirmation of rhEPO/DPO has been elusive due to the very low concentrations administered. Sample collection is typically acquired only after competition, which could be in excess of 72 hours following administration. Testing of rhEPO/DPO is further confounded by the complexity of the matrices in which the drug is typically found–plasma and urine.