Anemia in Chronic Kidney Disease

Abstract

Our reliance on oxygen to create energy has resulted in an evolutionary mechanism that uses the property of iron to transport oxygen to cells where it accepts electrons. The system relies on red blood cells carrying iron and oxygen in a complex molecule known as hemoglobin. During chronic kidney disease (CKD), red blood cell production falls. Interestingly, the kidney is the center for hypoxia sensing and red blood cell control. Although anemia in CKD was known in 1827, it was not until 1989 that a synthetic form of erythropoietin was developed. This increased the need for iron. It turns out that the role iron plays is far more complex than just a mere iron transporter. As the preferred electron transport mechanism for microbes, and as a power oxidant, iron metabolism is tied to inflammation and erythropoiesis. The management and control of anemia in CKD has been a major milestone in nephrology. Unfortunately, recombinant erythropoietin was surprisingly toxic at higher doses, as was unexpectedly discovered in large clinical trials. Newer agents such as HIFα inhibitors are emerging. The clotting mechanism in kidney patients is also discussed in this chapter as CKD patients are at high risk for venous thromboemboli.