[Diagnostic value of serum erythropoietin levels]

Erythropoietin (Epo) is a hormone-like glycoprotein regulating erythropoiesis. Under normal conditions Epo stimulates mitoses of the erythroid progenitors and precursors, decreases apoptosis, decreases "ineffective erythropoiesis" and stimulates the synthesis of the specific protein, haemoglobin. Epo producing cells in the kidney sense the O2 tension of kidney tissue and react to hypoxia with increased Epo production and to O2 saturation (polycythaemia) with decreased or completely abolished Epo production. Normal level of Epo in the serum is 3-20 mU/ml. If Epo production is functioning normally there exists a strict inverse correlation between serum Epo level and hematocrit: an exponential increase in Epo level can be observed if hematocrit decreases. Any damage in Epo production lead to inadequate production (e.g. renal anaemias). This paper analyses the Epo content of 278 serum samples assayed in the Laboratory of Experimental Bone Marrow Transplantation of the National Institute of Hematology and Immunology between August 1996 and December 1997 for their diagnostic value. Those samples are primarily discussed where Epo assay was meant to decide diagnosis of polycythaemia vera or those where decision of Epo treatment of anaemic patients depended on their serum Epo level.