Anaemia Of Chronic Disorders
One of the most common anaemias occurs in patients with a variety of chronic inflammatory and malignant diseases (Table 3.6). The characteristic features are:
1. Normochromic, normocytic or mildly hypochromic (MCV rarely <75 fL) indices and red cell morphology.
2. Mild and non‐progressive anaemia (haemoglobin rarely <90 g/L) – the severity being related to the severity of the disease.
3. Both the serum iron and TIBC are reduced.
4. The serum ferritin is normal or raised.
5. Bone marrow storage (reticuloendothelial) iron is normal but erythroblast iron is reduced (Table 3.7).
The pathogenesis of this anaemia appears to be related to decreased release of iron from macrophages to plasma because of raised serum hepcidin levels, reduced red cell lifespan and an inadequate erythropoietin response to anaemia caused by the effects of cytokines such as IL‐1 and tumour necrosis factor (TNF) on erythropoiesis.
The anaemia is corrected by successful treatment of the underlying disease and does not respond to iron therapy. Erythropoietin injections improve the anaemia in some cases. In many conditions this anaemia is complicated by anaemia resulting from other causes (e.g. iron, vitamin B12 or folate deficiency, renal failure, bone marrow failure, hypersplenism, endocrine abnormality, leucoerythroblastic anaemia) and these are discussed in Chapter 29.