HEMATOLOGICAL INDEXES OF ERYTHROPOIETIN ADMINISTRATION IN ATHLETES

Recombinant human erythropoietin (EPO), commercially available since 1 988, is thought to be used by athletes in aerobic sports for the purpo se of increasing oxygen transport and aerobic power. In an attempt to identify EPO administration, we have studied the peripheral blood of 2 0 subjects practising sports at an amateur level. Automated cytometry was performed on the blood samples before and during 45 days of EPO tr eatment. The same hematological indices were determined for a control population that consisted of 240 elite athletes from various sports. A s expected following EPO treatment, RBC, [Hb] and Hct increased signif icantly (increments of 8 %, 6.3 % and 11 %, respectively). A significa nt increase in reticulocyte count was also observed. In addition, auto mated erythrocyte analysis showed a significant increase in cells with a volume > 120 fl and hemoglobin content (HC) < 28 pg (hypochromic ma crocytes, or MacroHypo): 0.06 +/- 0.09 % before EPO, 0.48 +/- 0.63 % a fter EPO. The EPO-treated subjects differed from the control populatio n having higher values for Hct, mean corpuscular volume (MCV), Macro a nd MacroHypo. To investigate the possibility of using such variations in blood parameters to identify EPO treatment, individual values for H ct, MCV, Macro and MacroHypo for treated subjects and controls were pl otted. Using the percentages of MacroHypo, a cut-off value surpassed i n approximately 50 % of the treated subjects and in none of the contro ls was established. The presence of circulating MacroHypo in percentag es not found in untreated athletes could be employed as an indirect in dicator of EPO misuse only after the treated population and, more impo rtantly, the control population have been greatly expanded and the stu dy has been broadened to include races other than Caucasian. The ident ification of EPO misuse by these means will also require the availabil ity of blood samples for doping control. At present the International Ski Federation and the International Amateur Athletic Federation have this requirement.