Radioimmunoassay for erythropoietin using anti-recombinant erythropoietin antibody with high affinity

A sensitive radioimmunoassay (RIA) for the detection of erythropoietin (EPO) was developed using anti-recombinant EPO antibody with high affinity. The sensitivity was 100 amol/tube (5 mIU/ml) and it was possible to detect a serum EPO level between 5 and 200 mIU/ml. This method enabled us to measure native EPO as well as recombinant EPO. With this method we determined serum EPO levels in healthy individuals and patients with chronic renal disease, rheumatoid arthritis and iron deficiency anemia. Values in patients with chronic renal disease were lower than those in healthy individuals, while values in patients with rheumatoid arthritis, or iron deficiency anemia were significantly higher than those in healthy individuals.