Skip to main content
. 2020 Jan 9;106(2):384–390. doi: 10.3324/haematol.2019.233874

Figure 1.

Figure 1.

Effects of repeated administration of very low to low doses of recombinant human erythropoietin on total hemoglobin mass, erythropoietin, erythroferrone and hepcidin. (A) Total hemoglobin mass (Hbmass), determined at baseline (Pre) and 72 h after the last of the six injections (Post) of placebo (n=7), recombinant human erythropoietin (rhEpo) 20 IU/kg (micro-dose) (n=7) or rhEpo 50 IU/kg (low dose) (n=8). ANOVA for a significant time × treatment interaction (P=0.049). *Indicates a significant difference between low-dose rhEpo and placebo. Data are means ± standard deviations. Individual Hbmass values are available in Online Supplementary Figure S1. (B-D) Serum concentrations of erythropoietin (B), erythroferrone (ln transformed, n=7 for the placebo condition) (C) and hepcidin (ln transformed) (D) before, during and after six injections of placebo (n=8), micro-dose rhEpo (n=8) or low-dose rhEpo (n=8). Vertical dotted lines indicate injections. Baselines are means from duplicate blood samples collected on separated days. Blood sampling was repeatedly performed at 24 h (2 occurrences), 48 h (4 occurrences) and 72 h (2 occurrences) after an injection. Additional samples were obtained at 7 and 14 days after the last injection. Numbers above the abscissa line (i.e., 24, 48, 72, 7d and 14d) indicate these sampling times, respectively. Data are means ± standard deviations. For each panel, the inserted table reports estimated marginal means ± standard errors and P-values for the effect of the group (placebo, micro-dose, low dose), the occurrence (i.e., the number of samples at 24 h, 48 h, 72 h, 7 days and 14 days, from 1 to 4) and the group × occurrence (G × O) interaction. Multiple comparisons between groups at 24 h, 48 h or 72 h are reported in each table, *Denotes a difference from placebo and ‡denotes a difference from micro-dose rhEPO (see the Online Supplementary Material, Statistical analysis section). Epo: erythropoietin; ERFE: erythroferrone; PLA: placebo. EPO20: recombinant human erythropoietin 20 IU/kg; EPO50: recombinant human erythropoietin 50 IU/kg.