Recombinant Erythropoietin in Humans Has a Prolonged Effect on Circulating Erythropoietin Isoform Distribution

Abstract

The membrane-assisted isoform immunoassay (MAIIA) quantitates erythropoietin (EPO) isoforms as percentages of migrated isoforms (PMI). We evaluated the effect of recombinant human EPO (rhEPO) on the distribution of EPO isoforms in plasma in a randomized, placebo-controlled, double-blinded, cross-over study. 16 healthy subjects received either low-dose Epoetin beta (5000 IU on days 1, 3, 5, 7, 9, 11 and 13); high-dose Epoetin beta (30.000 IU on days 1, 2 and 3 and placebo on days 5, 7, 9, 11 and 13); or placebo on all days. PMI on days 4, 11 and 25 was determined by interaction of N-acetyl glucosamine with the glycosylation dependent desorption of EPO isoforms. At day 25, plasma-EPO in both rhEPO groups had returned to values not different from the placebo group. PMI with placebo, reflecting the endogenous EPO isoforms, averaged 82.5 (10.3) % (mean (SD)). High-dose Epoetin beta decreased PMI on days 4 and 11 to 31.0 (4.2)% (p<0.00001) and 45.2 (7.3)% (p<0.00001). Low-dose Epoetin beta decreased PMI on days 4 and 11 to 46.0 (12.8)% (p<0.00001) and 46.1 (10.4)% (p<0.00001). In both rhEPO groups, PMI on day 25 was still decreased (high-dose Epoetin beta: 72.9 (19.4)% (p = 0.029); low-dose Epoetin beta: 73.1 (17.8)% (p = 0.039)). In conclusion, Epoetin beta leaves a footprint in the plasma-EPO isoform pattern. MAIIA can detect changes in EPO isoform distribution up til at least three weeks after administration of Epoetin beta even though the total EPO concentration has returned to normal.

Detection of erythropoietin misuse by the Athlete Biological Passport combined with reticulocyte percentage

“…Statistical significant differences are: * different from placebo (P < 0.05), ** different from placebo (P < 0.01), *** different from placebo (P < 0.001), # different from day 4 within treatment (P < 0.05), ## different from day 4 within treatment (P < 0.01), ### different from day 4 within treatment (P < 0.001) and §§§ different from day 11 within treatment (P < 0.001). The data for [Hb] has also been described elsewhere …”

“…The changes in [Hb] during all three treatments are described elsewhere. [18] An interaction (time × treatment) existed for ret% (P < 0.05) and changes are illustrated in Figure 1. During high-dose treatment ret% was 140 ± 84 % and 131 ± 92 % higher (P < 0.001) compared with placebo at days 4 and 11, respectively, and 21 ± 32 % lower (P < 0.05) compared with placebo at day 25.…”

“…The venous blood samples were cooled, sent for analysis, and one analyses per sample was performed within 2 h of collection using a Sysmex XE2100 (Sysmex, Norderstedt, Germany). The results of [Hb] have been described elsewhere …”

“…The data for [Hb] has also been described elsewhere. [18] Adaptive model of the Athlete Biological Passport Sensitivity and specificity for the adaptive model were examined for [Hb], OFF-hr and ret% for the longitudinal and single sample approach as described in Methods. When results from blood samples obtained during placebo treatment were analyzed by the ABP software, 1 out of 46 placebo samples exceeded the 99 % specificity level for either [Hb] or OFF-hr, resulting in a specificity of 97.8 %, while the specificity was 91.3 % when ret% was added as well.…”

Reduction in central venous pressure enhances erythropoietin synthesis: role of volume‐regulating hormones

“…EPO concentration was determined through the Human EPO Quantikine IVD ELISA Kit (R&D Systems), as previously described (Aachmann‐Andersen et al . ). In addition, to determine changes in hemoconcentration, albumin levels were assessed with ALB reagent in conjunction with UniCel ® DxC 600/800 and Synchron ® Systems Multi Calibrator (Beckman Coulter, Brea, CA, USA).…”