Patients with chronic renal disease fail to produce adequate quantities of the hormone erythropoietin. The erythropoietin gene is located on chromosome 7 and codes for a 193 amino acid glycopeptide. Erythropoietin is predominantly synthesized by cells in the peritubular cortex of the kidney. It stimulates proliferation and differentiation of red cells in the bone marrow. In the absence of erythropoietin anaemia develops. Prior to the availability of erythropoietin this necessitated patients with renal failure having regular blood transfusions, with the attendant risks.
Recombinant DNA technology now allows the production of synthetic erythropoietin and it can be administered to patients with anaemia secondary to renal failure, either subcutaneously or intravenously.
Anaemia is also exacerbated by an iron-deficiency picture, often seen in children with CRF. This should be treated with oral iron supplements and if this is ineffective, intravenous iron is given. Anaemia may respond to iron alone and if iron deficiency is a problem, erythropoietin is far less effective.