Current limitations and future perspectives of the Athlete Blood Passport

Abstract

We read with interest the recent article of Ashenden et al. (2011) and, frankly, we are not really surprised about their findings, i.e., that the Athlete Blood Passport (ABP) software did not ‘‘flag’’ subjects who were receiving microdoses of recombinant human erythropoietin (rHuEPO). Despite its well-known analytical shortcomings, there is broad agreement that the ABP is currently a useful approach for safeguarding an athlete’s health in the presence of abnormal laboratory data (Zorzoli 2011). Nevertheless, for those who are familiar with sports and laboratory hematology, it would seem that the ABP has been mainly developed to detect substantial and acute variations in hematological parameters consistent with blood ‘‘boosting’’, and is therefore perhaps less effective at identifying mild or less pronounced abnormalities (Lippi and Plebani 2011). Several limitations have been noted with the ABP, which should be taken into consideration when interpreting test results. These include biological, pre-analytical (Lippi et al. 2010) and analytical variability (Banfi et al. 2011), as well as categorization according to different metabolic energy demands, hypoxia treatments during exercise, use of masking agents (Banfi 2011; Sanchis-Gomar et al. 2011), and now microdoses of rHuEpo. It is also conceivable that repeated ‘‘microtransfusions’’, as well as the combined use of minimal doses of rHuEpo in combination with ischemia modulators such as cobalt chloride, could produce substantial hematological improvements and performance benefits (Lippi et al. 2006), while remaining undetectable by current antidoping algorithms. Additional caveats include the lack of standardization and diagnostic thresholds for detecting doping which should be more clearly assessed to limit ambiguity (Banfi 2011; Sanchis-Gomar et al. 2011). The influence of factors such as exhaustive endurance exercise on vascular volumes should be considered to avoid misinterpretation of ABP software results (Sanchis-Gomar et al. 2011), especially because diurnal and exercise-related variations of hemoglobin levels have been reported due to plasma volume expansion following regular endurance exercise (Schumacher et al. 2010). Interestingly, Schumacher and Pottgiesser (2011) have recently shown that fluid loss associated with gastroenteritis, a condition not uncommon in athletes, is unlikely to cause blood data to reach levels of abnormality that would be consistent with blood doping. The results of this study are valuable, but additional investigations should be undertaken to clarify, for example, whether some common forms of bleeding (e.g., Communicated by Susan A. Ward.