title: Effect of exogenous erythropoietin on haem synthesis in anaemic patients with rheumatoid arthritis.
abstract: The effect of recombinant human erythropoietin (rHuEPO) on haem biosynthesis in peripheral red blood cells was evaluated in 12 patients with RA and anaemia (mean haemoglobin concentration 102 g/l, range 90-109 g/l). Before treatment, the serum concentrations of erythropoietin (EPO) were low (mean 13 pmol/l, range 5-32 pmol/l), the activities of haem-synthesizing enzymes within the reference intervals and the erythrocyte protoporphyrin (E-PROTO) concentrations clearly higher than normal. Nine patients responded with an increase in the haemoglobin level of 15 g/l or more. rHuEPO induced a rise in the mean haem synthase (HAEM-S) activity from a baseline of 12.1 to a maximum of 26.8 pmol/h per 10(6) reticulocytes after 20 weeks of treatment (P < 0.002). The mean E-PROTO concentration also rose and reached its maximum at 8 weeks of treatment. We conclude that correction of anaemia in patients with RA using rHuEPO is associated with an activation of HAEM-S, commonly regarded as the rate-limiting enzyme of haem synthesis in erythroid cells. Functional iron deficiency probably explains the simultaneous rise in E-PROTO concentration.
authors.affiliation: Fourth Department of Medicine, Helsinki University Central Hospital, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Pettersson
authors.forename: K
authors.initials: K
authors.lastname: Rosenlöf
authors.forename: E
authors.initials: E
authors.lastname: Laitinen
authors.forename: R
authors.initials: R
authors.lastname: Tenhunen
mesh_terms: D000328:Adult; D000368:Aged; D000740:Anemia / Q000097:blood* / Q000150:complications / Q000628:therapy; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000150:complications; D004912:Erythrocytes / Q000737:chemistry / Q000187:drug effects / Q000378:metabolism; D004921:Erythropoietin / Q000627:therapeutic use*; D005260:Female; D006418:Heme / Q000096:biosynthesis*; D006454:Hemoglobins / Q000032:analysis / Q000187:drug effects; D006801:Humans; D008297:Male; D008875:Middle Aged; D011524:Protoporphyrins / Q000032:analysis
chemical_list: D006454:Hemoglobins; D011524:Protoporphyrins; D004921:Erythropoietin; D006418:Heme