Serum Erythropoietin Concentration in Anephric Patients

Abstract

In 13 bilateral nephrectomized patients serum erythropoietin (SEp) activity could be measured quantitatively by use of the highly sensitive fetal mouse liver cell assay. SEp concentration in the majority of the cases was below the mean of normal controls. There was a significant positive correlation between SEp levels and hematocrits, suggesting erythropoietin (Ep) deficiency to be a causative factor in the anemia of the anephric state. Androgen therapy stimulated extrarenal Ep production in all of 5 anephric patients studied.

Pathogenesis of Endocrine Abnormalities in Uremia*

“…These disorders are characterized either by absolute decrements in the circulating levels of the respective hormones (1,25-dihydroxycholecalcipherol, gonadal steroids, and T 3 ) or, as in the case of erythropoietin, by a relative deficiency, i.e. inappropriately low circulating concentrations for the level of target tissue function (10,130,(136)(137)(138).…”

“…Whereas the pathogenesis of renoprival anemia is multifactorial, impaired erythropoietin production is thought to be its main cause (139) (138,143)]. It is obvious, however, that erythropoietin levels in renal failure are inappropriately low for the degree of anemia.…”

“…It should be noted that the minimal detectable erythropoietin concentration with the polycythemic mouse assay employed for anemic patients with normal renal function (144) is =0.2 U/ml, while the fetal mouse hepatocyte method used in the study of uremics detects EPO levels as low as 0.005 U/ml (138) patients (145,146). This occurs despite evidence for extrarenal erythropoietin secretion in anephric individuals (138,(147)(148)(149). The extrarenal production sites of the hormone seem to retain their responsiveness to hypoxia and plethora, as evidenced by reticulocytosis after hemorrhage or reduction in marrow erythroblasts after transfusion (150).…”

“…The extrarenal production sites of the hormone seem to retain their responsiveness to hypoxia and plethora, as evidenced by reticulocytosis after hemorrhage or reduction in marrow erythroblasts after transfusion (150). Furthermore, the administration of androgens to such patients frequently augments red cell mass and, allegedly, erythropoietic activity (138), although considerable controversy exists regarding their effects on iron incorporation in the in vitro systems used for these measurements (151,152).…”

Die Rolle des Erythropoietinmangels in der Pathogenese der renalen An�mie

“…Die Ergebnisse belegen im Obrigen, dab die Korrektur der renalen An~imie durch die Hfimodialysetherapie nicht -wie diskutiert wurde [1,12,20,27] -Folge einer Z u n a h m e der renalen oder extrarenalen E r y t h r o p o i e t i n p r o d u k t i o n ist. In A n b e t r a c h t der von uns an einer G r u p p e anephrischer Patienten e r h o b e n e n Befunde [36] erscheint es fraglich, ob auch bei diesen Patienten im Individualfall eine Regulierbarkeit der Serumerythropoiet i n k o n z e n t r a t i o n fiber den Hfimatokrit im Sinne eines negativen feedback erfolgt. Eine p e r m a n e n t maximale Stimulation der extrarenalen E r y t h r o p o i e t i n p r o d u ktion unabh~ingig vom Anfimiegrad ist wahrscheinlicher.…”