Erythropoiesis and iron metabolism in dominant erythropoietic protoporphyria.

Abstract

Erythropoietic protoporphyria (EPP) results from deficiency of ferrochelatase (FECH). Accumulation of protoporphyrin IX causes life-long acute photosensitivity. Microcytic anemia occurs in 20% to 60% of patients. We investigated 178 patients with dominant EPP confirmed by molecular analysis. Erythropoiesis was impaired in all patients; all had a downward shift in hemoglobin (Hb), and the mean decreased in males by 12 g/L (1.2 g/dL). By World Health Organization criteria, 48% of women and 33% of men were anemic. Iron stores, assessed by serum ferritin (sFn), were decreased by two-thirds, but normal serum soluble transferrin receptor-1 and iron concentrations suggested that erythropoiesis was not limited by iron supply. FECH deficiency in EPP appears to lead to a steady state in which decreased erythropoiesis is matched by reduced iron absorption and supply. This response may in part be mediated by protoporphyrin, but we found no correlation between erythrocyte protoporphyrin and Hb, sFn, total iron-binding capacity, or transferrin saturation.

• Authors: S Alexander Holme, Mark Worwood, Alexander V Anstey, George H Elder, Michael N Badminton
• Journal: Blood (Blood) Vol. 110 Issue 12 Pg. 4108-10 (Dec 01 2007) ISSN: 0006-4971 [Print] United States
• PMID: 17804693 (Publication Type: Journal Article, Multicenter Study, Research Support, Non-U.S. Gov't)

Chemical References

• Antigens, CD
• CD71 antigen
• Hemoglobins
• Protoporphyrins
• Receptors, Transferrin
• Ferritins
• protoporphyrin IX
• Iron
• Ferrochelatase

Topics

• Anemia (blood, enzymology)
• Antigens, CD (blood)
• Cross-Sectional Studies
• Erythrocytes (enzymology, metabolism)
• Erythropoiesis
• Female
• Ferritins (blood)
• Ferrochelatase
• Hemoglobins (analysis)
• Humans
• Iron (blood)
• Male
• Photosensitivity Disorders (blood, enzymology)
• Protoporphyria, Erythropoietic (blood, enzymology)
• Protoporphyrins (blood)
• Receptors, Transferrin (blood)
• Sex Factors