EPO and the athlete biological passport: Hematological results from a placebo-controlled, boosting and microdose EPO administration in male recreational athletes.

Hematological results in the context of the Athlete Biological Passport (ABP) from a placebo-controlled EPO administration study are provided here. Twelve participants administered eight subcutaneous boosting doses of epoetin alfa (at 40 IU/kg) over the course of 20 days. After a 10-day washout period, the same volunteers administered six microdoses (900 IU), intravenously, over 13 days. A blinded placebo cohort followed the same dosing pattern, administering saline instead of EPO. All participants supplemented with oral iron, daily, throughout the entirety of the study. In the EPO cohort, as expected, significant changes from baseline were identified in IRF, RET#, RET%, RDW, HCT, HGB, and RBC. No meaningful changes were identified in the placebo cohort population. From the ABP perspective, atypical passport findings (ATPF) were identified in 49% of the samples collected during the boosting and initial washout phases, and 24% of the samples during the microdosing and final washout phases. ATPFs from this cohort were flagged as late as Day 70, the final day of the study. Only a single ATPF was identified from all samples collected from the placebo cohort. ABPs from all volunteers in the study are provided as an avenue to visually convey differences in magnitude and timing of the hematological changes caused by EPO on the individual level. These data are expected to provide important content for Athlete Passport Management Units and ABP expert panels alike.