Anemia of Inflammation: A Review.

Impaired iron homeostasis and the suppressive effects of proinflammatory cytokines on erythropoiesis, together with alterations of the erythrocyte membrane that impair its survival, cause anemia of inflammation. Recent epidemiologic studies have connected inflammatory anemia with critical illness, obesity, aging, kidney failure, cancer, chronic infection, and autoimmune disease. The proinflammatory cytokine, interleukin-6, the iron regulatory hormone, hepcidin, and the iron exporter, ferroportin, interact to cause iron sequestration in the setting of inflammation. Although severe anemia is associated with adverse outcomes in critical illness, experimental models suggest that iron sequestration is part of a natural defense against pathogens.