Anemia of chronic disorders develops in chronic inflammatory (especially rheumatic), infectious, advanced malignant diseases, and chronic heart failure. It is the second most common form of anemia world wide after iron deficiency anemia .
The cause of anemia of chronic disorders is multifactorial. The most important factor is a disorder of iron distribution. Inflammatory factors (Il-1, Il-6, TNF-alpha) lead to an increase of hepcidin and consequently to a reduced iron resorption and a reduced iron release from macrophages. Therefore, iron is not available for erythropoiesis. Additional factors are a reduced life span of erythrocytes (80-90 days instead of 100-120 days), a reduced production of erythropoietin as well as a relative resistance to erythropoietin.
This anemia is rarely severe (Hb in most cases > 90 g/L). Its severity usually correlates with the severity of the underlying disease process. The patients most often have asymptomatic anemia. Frequent symptoms such as fatigue and weakness can also be caused by the underlying illness.
Anemia of chronic disorders is normally normochromic and normocytic with a tendency to be hypochromic-microcytic. Serum iron is decreased while transferrin saturation is normal to low and serum ferritin is normal or high. Additionally, RDW is normal in contrast to iron deficiency anemia.
Please note! Anemia of chronic disorders and iron deficiency anemia often coexist (e.g., in the case of patients with rheumatoid arthritis and drug-induced gastrointestinal bleeding).
The examination of bone marrow is not an essential component of the clinical investigation of anemia of chronic disorders. However, it can be helpful to exclude iron deficiency anemia or a myelodysplastic syndrome. In anemia of chronic disorders, the iron content of bone marrow is typically normal or increased.