Anemia of Chronic Disease (Anemia of Inflammation)
- Anemia that accompanies a variety of systemic diseases, with the common features of chronicity and inflammation
- Anemia of chronic disease is more properly called anemia of inflammation (AI) and is the combined result of mildly increased destruction of RBCs, relative erythropoietin resistance, and iron-restricted erythropoiesis.
Typically mild to moderate anemia (Hgb 7 to 12 g/dL); develops in the setting of infection, inflammatory disorders, and some malignancies
- Deficient cellular iron in the setting of hepcidin excess (functionally inaccessible iron)
- Typically normochromic, normocytic but, if long-standing, can be hypochromic, microcytic (especially in children)
- Main mechanism appears to be
- Hepcidin is increased by interleukin-6 (IL-6), causing depletion of ferroportin, the only known membrane iron transporter.
- Elevated hepcidin results in macrophage inability to release iron recycled from senescent RBCs, hepatocyte inability to release stored iron, and enterocyte inability to absorb dietary iron.
- These changes lead to iron restriction with decreased iron available for erythropoiesis.
- Other factors contributing to anemia in various degrees include the following:
- Increased red cell destruction
- Diagnostic phlebotomy or other blood loss
- Inflammatory cytokines suppress erythropoiesis
- Cytokine-mediated suppression of erythropoiesis
- Cytokines such as interleukin-1 (IL-1) and IL-6 can activate ferritin synthesis, leading to sequestration of iron, which eventually is converted into hemosiderin.
Underlying disease process
Commonly Associated Conditions
- Underlying disease process
- Infections, both acute and chronic
- Inflammatory disease
- Collagen vascular diseases
- Renal failure
- Anemia of chronic disease often coexists with other causes of anemia, including:
- Occult blood loss
- Dietary iron deficiency
- Drug-related marrow suppression
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