Anaemia of Chronic Disease (ACD) is common, particularly in the hospital setting. It occurs as a result of:
- Chronic infection
- Chronic inflammation
is not related to bone marrow, bleeding or haemolysis, and is generally mild (Hb of 8.5-11.5g/dl).
The pathology is not well known. It is thought to arise from defects in iron utilisation, in particular, iron is not released from transferrin as well as normal. This seems to have an effect on erythropoiesis, and the level of EPO is reduced, although it often appears very low for such a mild anaemia. Basically – there is inhibition of erythrocyte production by cytokines.
- The administration of EPO to patients with rheumatoid arthritis has shown to be of benefit to these patients.
- Note that transferrin is the protein used to transport iron in the blood. It binds iron very strongly, but reversibly.
- Ferritin is a compound that binds free iron within cells. In anaemia of chronic disease, levels of ferritin are often raised.
There are normal levels of iron stores in the bone marrow, but this, for some reason, is not released properly, and so developing erythroblasts do not receive enough of it. Therefore, the actual RBC’s will mimic those of IDA.
Anaemia of chronic disease is generally a normocytic normochromic anaemia, but sometimes it can be a microcytic hypochromic
IDA is a microcytic hypochromic anaemia
It is thought that somewhere along this process of iron release, interferons, TNF and cytokines, such as IL-1, interfere with the release of iron.
It can be difficult to differentiate ACD from iron deficiency anaemia – they both have a low MCV. You may need to try a trial of oral iron. In ACD this will not improve the situation, but in IDA it should.
In ACD measures that treat the underlying condition will generally result in resolution of the anaemia.
You could also do an immunoassay to look at the number of serum transferrin receptors, as levels of these differ between diseases.
Soluble transferrin receptor
Normochromic – this means the concentration of haemoglobin within an RBC is normal.
Treatment is generally just that of the underlying disorder. – However, in those with terminal malignancy, you may be able to improve quality of life by giving them EPO to reduce the level of anaemia. This is also helpful in cases of renal failure as in renal disease levels of EPO are directly affected.
MCV – mean corpuscular volume – this tell you if it is micro / normo / macrocytic
MCH – mean corpuscular haemoglobin – this tells you if it is normo/hyper/hypo chromic
MCHC – mean corpuscular haemoglobin concentration – this is just basically a calculation using MCV and MCH – it is not that useful!