[Renal anemia and hypoxia-inducible factor prolyl hydroxylase inhibitor]

Anemia is a significant complication of chronic kidney disease (CKD), caused by erythropoietin deficiency and reduced iron availability. Erythropoiesis-stimulating agents have been used with iron supplementation to treat anemia; however, they are associated with some problems. Hypoxia-inducible factor prolyl hydroxylase inhibitor (HIF-PHI) is a promising new class of oral therapy for the treatment of anemia associated with CKD. HIF-PHI inhibits HIF-prolyl hydroxylase enzymes and results in the HIF-α accumulation, which leads to increased expression of HIF-responsive genes, including erythropoietin and vascular endothelial growth factor (VEGF). HIF stimulates endogenous erythropoietin production and also reduces circulating hepcidin concentrations, resulting in improved anemia. Many clinical trials demonstrate that HIF-PHI improves anemia in patients with CKD and on dialysis. In addition to treating anemia, HIF-PHI may have multiple potential effects. Several animal experiments show that HIF-PHI protects against ischemic kidney damage that progresses to CKD and also improves metabolic disorders and ameliorates cardiovascular complications. In contrast, malignant tumor and retinopathy should be carefully evaluated due to theoretical concerns that HIF stabilization may result in increased VEGF protein expression. Some adverse events such as shunt occlusion reported in large clinical trials also need attention and warrant further investigations.