THE SERUM ERYTHROPOIETIN AND ERYTHROPOIETIN RECEPTOR CONCENTRATION IN PATIENTS WITH MAINTENANCE HEMODIALYSIS The purposes of this study were to determine erythropoietin concentration and erythropoietin receptor concentration in patients with maintenance hemodialysis (HD). Subjects and method: 248 subjects divered into 2 groups: 175 patients HD and 73 healthy subjects in control group.