Screening for Autologous Blood Transfusions

The ratio between the amount of hemoglobin in the mature erythrocyte population and the reticulocytes (RBCHb:RetHb ratio) has previously been suggested as a marker to screen for EPO-abuse. We speculated that the reinfusion of blood would lead to a marked increase in this ratio, making it a valuable parameter in the screening for autologous blood doping. Three bags of blood (similar to 201 +/- 11g of Hb) were withdrawn from 16 males and stored at either -80 degrees C (-80T, n=8) or +4 degrees C(+4T, n=8)and reinfused 10 weeks or 4 weeks later, respectively. Seven subjects served as controls. Different erythrocyte parameters were measured on a hematological analyzer serially throughout and during a 4 week washout period. By using RBCHb:RetHb ratio cut-off limits of 145.7 (1:100) ('suspicious') and 182.9 (1:1000) ('positive'), 35.4% (-80T) and 19.6% (+4T) of all samples obtained during a 4 week wash-out period were identified as 'suspicious', and 18.8% (-80T) and 4.3% (+4T) as 'positive'. In total, 7 out of 16 (43.8%) subjects had at least one sample exceeding 182.9. Compared to the currently used indirect parameters, the RBCHb: RetHb ratio is the best indicator of autologous blood doping after reinfusion, and the parameter could be used in a testing setting, once stability validation has been performed.