[Serum erythropoietin levels in several diseases]

The accurate radioimmunological measurement of serum erythropoietin (EPO) levels has only been possible since the development of highly specific antibodies directed against recombinant human EPO. In the present study, we determined the serum EPO levels in 100 healthy volunteers and in over 300 patients with anemias and hyperglobulinemia of various causes. In the healthy group, the females had levels of 11.3 +/- 3.4 mU/ml, while the males had levels of 8 +/- 3.2 mU/ml. The serum EPO concentrations were inversely related to the degree of anemia in patients with nonrenal anemias, while predialysis patients with renal anemias showed only partially such a tendency. Hemodialysis patients exhibited EPO-levels that were inadequately low relative to the degree of anemia. Patients with hyperglobulinemia had significantly higher serum EPO-levels than healthy individuals and polycythemia vera patients, the latter having particularly low serum EPO levels. Our results show that the determination of serum EPO levels can be of value in the differential diagnosis of hyperglobulinemia. Finally, sequential measurements document fluctuating serum EPO-levels after gastrointestinal hemorrhages and in patients with iron deficiency anemias receiving iron substitution. The probable reason for this phenomenon seems to be the intermittent utilisation of the hormone by EPO-sensitive erythropoietic precursor cells.