Anaemia of Chronic Disease

Background

• Second most common form of anaemia.  Particularly common in hospital patients
  • Chronic infection, inflammation or neoplasia
  • Not related to bleeding, haemolysis or marrow infiltration
• Usually mild (85-115g/l) and is usually normochromic normocytic

Pathophysiology

• Not fully understood but different processes involving iron homeostasis, erythropoiesis and response to erythropoietin have been shown to be involved.
• A key factor involved is IL-6 (commonly expressed in a range of diseases e.g. inflammatory conditions and chronic renal disease)
  • Induces expression of hepcidin in the liver which binds to ferroportin on the membranes of iron-exporting cells e.g. enterocytes and macrophages, internalising the ferroportin and inhibiting the export of iron.
    • Iron is trapped as ferritin within the cells
      • Serum iron is low but ferritin is normal/high

Conditions commonly associated with ACD

• Infections (viral, bacterial, parasitic or fungal)
• Autoimmune conditions (rheumatoid arthritis; SLE; Vasculitides; Sarcoidosis; IBD)
• Chronic kidney disease
• Chronic heart failure

Presentation

• Usually there will be an underlying cause with its own symptoms
• Patients may be more tired, breathless, pale etc than normal

Investigations

• It can be difficult to differentiate ACD from Iron-deficiency anaemia (both can have a reduced haemoglobin and MCV)
  • Iron studies will usually show low iron but normal/high ferritin in ACD (cf IDA in which both will be low)

Management

• Often conservative management is all that is required (usually mild symptoms)
• If there is an iron deficiency, treat this with iron.  If uncertain, a trial of oral iron can be given to assess the response.
• If severe anaemia and/or symptoms are problematic, consider transfusion.  However, this is often only used as a palliative measure (symptom control)