Hepcidin and erythroferrone complement the Athlete Biological Passport in the detection of autologous blood transfusion

Purpose: We investigated whether hepcidin and erythroferrone (ERFE) could complement the Athlete Biological Passport (ABP) in indirectly detecting a 130 mL packed red blood cells (RBCs) autologous blood transfusion. Endurance performance was evaluated.

Methods: Forty-eight healthy men (n = 24) and women (n = 24) participated. Baseline samples were collected weekly followed by randomization to a blood transfusion (BT, n = 24) or control group (CON, n = 24). Only the BT group donated 450 mL whole blood from which 130 mL RBCs was reinfused four weeks later. Blood samples were collected 3, 7, 14, 21 and 28 days after donation, and 3, 6, and 24 hours and 2, 3, and 6 days following reinfusion. In the CON group samples were collected with the same frequency. Endurance performance was evaluated by a 650-kCal time trial (n = 13) before and one and six days after reinfusion.

Results: A time×treatment effect existed (P < 0.05) for hepcidin and ERFE. Hepcidin was increased (P < 0.01) ~110 and 89% six and 24 hours after reinfusion. Using an individual approach (99% specificity, e.g. allowing 1:100 false-positive), sensitivities, i.e. true positives, of 30% and 61% was found for hepcidin and ERFE, respectively. For the ABP, the most sensitive marker was Off-hr score ([Hb] (g·L^-1) - 60 × √RET%) (P < 0.05) with a maximal sensitivity of ~58% and ~ 9% following donation and reinfusion, respectively. Combining the findings for hepcidin, ERFE and the ABP yielded a sensitivity across all time-points of 83% following reinfusion in BT. Endurance performance increased 24 hours (+6.4%, P < 0.01) and six days following reinfusion (+5.8%, P < 0.01).

Conclusions: Hepcidin and ERFE may serve as biomarkers in an anti-doping context following an ergogenic, small-volume blood transfusion.