Investigation on the application of DNA forensic human identification techniques to detect homologous blood transfusions in doping control

Homologous blood transfusion is an illicit practice used by athletes to improve the delivery of oxygen to tissues and, as such, it is banned in sports. The current method of detection is based on the flow cytofluorimetric phenotypic identification of red blood cells mismatch of minor blood group antigens between the donor and the recipient. The selectivity of this method to clearly identify transfused samples is related to the number of blood group antigens tested. Despite the fact that several different antigens are investigated, two individuals sharing the expression of the same minor blood group antigens pattern cannot be distinguished. We tested the possibility to use a different approach based on DNA forensic human identification techniques. Analysis of the DNA short tandem repeats (STRs) demonstrated its suitability in detecting mixed whole blood samples simulating homologous blood transfusion in 100% of the samples tested, ensuring the capability of clearly detecting mixed blood cell populations also on samples where the fraction of the minoritary population is as low as 2.5%.