ERYTHROPOIETINBESTIMMUNGEN IM SERUM. VERGLEICH EINES KOMMERZIELLEN ELISA MIT HERKOMMLICHEN BIOLOGISCHEN UND RADIOIMMUNOLOGISCHEN METHODEN

With immunoassay kits for erythropoietin coming into the market the question arises as to the correlation of the results based on different assay methods. Comparative measurements of erythropoietin were carried out with a commercial monoclonal-based, two-site enzyme immunoassay (ELISA) in frozen serum samples which were previously analysed for erythropoietin by bioassay in polycythaemic mice or by radioimmunoassay. There was a good correlation between the results obtained by the ELISA and the bioassay (r = 0.95; 50 sera) or the radioimmunoassay (r = 0.94; 80 sera), when compared in the concentration range of 25-10000 U/l. The ELISA had a low detection limit (2.0 U/l). The variation coefficients, which were determined in the concentration range of 6-90 U/l, were acceptable (intraassay < 11% and inter-assay < 28%). The normal serum concentration of erythropoietin was determined to be 14.3 U/l (95% confidence limit 5.8 - 34.9 U/l, 64 subjects) with the ELISA. This value was independent of the sex and age of the blood donors. The ELISA described here provides a convenient and sensitive non-radioactive system for the measurement of eryhropoietin for basic research purposes as well as for clinical studies of disorders of erythropoiesis.