Serum erythropoietin and erythroid activity in vitamin B12 deficiency.
We studied erythropoiesis in 31 patients with vitamin B12 deficiency by measuring serum erythropoietin (s-Epo), serum transferrin receptor (s-TfR, taken as an index of total erythroid activity), reticulocyte count, and the reticulocyte maturation index (RMI). s-Epo and s-TfR were measured with commercial immunoassays, whereas reticulocyte count and RMI were determined by flow cytometry. s-Epo (123 +/- 196 U/L) and s-TfR (4.1 +/- 2 mg/L) levels were increased in patients with vitamin B12 deficiency. The absolute reticulocyte counts were decreased (29 +/- 18 x 10(9)/L) with a relative increase in the most immature fractions (RMI: 29.6 +/- 18%). A significant negative relationship was found between s-Epo and Hb level (r = -0.65, p < 0.0001). On the average, however, s-Epo was inappropriately low for the degree of anemia, since the observed/predicted (O/P) s-Epo ratio was 0.80 +/- 0.28 in vitamin B12 deficiency vs 1.00 +/- 0.16 in a group of patients with iron deficiency anemia. It is concluded that at least a portion of patients with vitamin B12 deficiency have serum erythropoietin levels that are inappropriately low for the degree of anemia.
Remacha
A F
AF
Hematology Department, Hospital de la Santa Creu i Sant Pau, Barcelona, Spain.
Bellido
M
M
García-Die
F
F
Marco
N
N
Ubeda
J
J
Gimferrer
E
E
D000293:Adolescent; D000328:Adult; D000368:Aged; D000747:Anemia, Hypochromic / Q000097:blood; D000752:Anemia, Pernicious / Q000097:blood / Q000150:complications; D003404:Creatinine / Q000097:blood; D004921:Erythropoietin / Q000097:blood* / Q000172:deficiency; D005260:Female; D005293:Ferritins / Q000032:analysis; D006454:Hemoglobins / Q000032:analysis; D006801:Humans; D008286:Malabsorption Syndromes / Q000097:blood; D008297:Male; D008875:Middle Aged; D011178:Postgastrectomy Syndromes / Q000097:blood; D011990:Receptors, Transferrin / Q000097:blood; D017701:Reticulocyte Count; D014806:Vitamin B 12 Deficiency / Q000097:blood* / Q000209:etiology
D006454:Hemoglobins; D011990:Receptors, Transferrin; D004921:Erythropoietin; D005293:Ferritins; D003404:Creatinine