Ab. Schwartz et Cs. Orquiza, THE EFFECTS OF RECOMBINANT-HUMAN-ERYTHROPOIETIN ON MEAN CORPUSCULAR VOLUME IN PATIENTS WITH THE ANEMIA OF CHRONIC-RENAL-FAILURE, Clinical nephrology, 43(4), 1995, pp. 256-259
In historical studies erythropoietin stimulated bone marrow was shown
to produce less stable, macrocytic, ''stress erythrocytes''. Recent wo
rk from our lab suggests that erythropoietin serves as both a growth f
actor and as a survival factor. To investigate the effects of recombin
ant human erythropoietin (rHuEPO) on development of red blood cell siz
e of these longer lived erythrocytes, rHuEPO in 50-150 U/kg/dose was a
dministered to patients with the anemia of chronic renal failure (CRF)
. Mean corpuscular volume (MCV) was determined at control, short term
(n = 117, avg. 53 d), intermediate term (n = 73, avg. 136 d) and at lo
ng term (n = 66, avg. 221d) for effects of rHuEPO. Statistical evaluat
ion at these time points was made comparing all patients to themselves
as their own controls and using contingency tables for distribution o
f RBC size change. MCV at both short term (p =.02) and intermediate-te
rm (p <.01) was decreased; there was no change (p =.71) at the long te
rm. Analysis of distribution showed a significant (p <.01) trend towar
d microcytosis at short- and intermediate terms. This decrease of MCV
and trend toward microcytosis is consistent with iron deficiency secon
dary to the early, rapid increase in bone marrow iron utilization and
early increased reticulocytosis. Previous reports from our laboratory
coupled with data presented in this report refute earlier findings tha
t rHuEPO creates a ''stress'' mechanism producing less stable macrocyt
es.