Anaemia of Chronic Disease

Overview – Anaemia of Chronic Disease

Anaemia of chronic disease (ACD), also called anaemia of inflammation, is a common, mild-to-moderate anaemia seen in patients with chronic infections, autoimmune diseases, or malignancy. Unlike iron deficiency, ACD involves impaired iron utilisation and suppressed erythropoiesis — despite normal or increased iron stores. It is usually normocytic, though it may present as microcytic in long-standing disease. Management focuses on treating the underlying condition and addressing inflammation-driven marrow suppression.

Definition

• Anaemia caused by chronic inflammation, infection, or malignancy
• Characterised by impaired iron release, ↓ erythropoietin (EPO) production, and ↓ RBC survival
• Typically normocytic, sometimes microcytic

Aetiology

• Chronic infections: tuberculosis, osteomyelitis
• Autoimmune diseases: rheumatoid arthritis, systemic lupus erythematosus (SLE), IBD
• Malignancy: especially solid tumours and haematological cancers

Pathophysiology

• Chronic inflammation → cytokine-mediated changes:
  • ↓ RBC lifespan
  • ↓ EPO secretion by kidneys
  • Iron sequestration in macrophages → ↓ iron availability for erythropoiesis
  • Net result = functional iron deficiency, despite adequate iron stores

Morphology

• Normocytic, normochromic (typically)
• Sometimes microcytic
• Hypochromic features in chronic or advanced cases
• ↓ RBC count
• ↓ reticulocyte count

Clinical Features

• Usually mild anaemia
• Presents with general anaemia symptoms:
  • Fatigue
  • Pallor
  • Dyspnoea on exertion
• Often overshadowed by the symptoms of the underlying chronic condition

Investigations

Blood Tests

• ↓ Hb
• ↓ Reticulocytes

Iron Studies

• ↓ Serum iron
• ↓ TIBC
• Normal or ↑ Ferritin (iron is present but trapped in macrophages)

Others

• Normal B12 and folate
• Blood film: normocytic or microcytic RBCs with hypochromia

Management

• Treat underlying disease:
  • Infections, autoimmune inflammation, or malignancy
  • Immunosuppression (e.g. corticosteroids) if inflammatory
• Support erythropoiesis:
  • Exogenous erythropoietin (EPO) for selected cases
• Iron supplementation is not effective unless coexisting iron deficiency

Summary – Anaemia of Chronic Disease

Anaemia of chronic disease is a mild, usually normocytic anaemia driven by long-standing inflammation, impaired iron utilisation, and reduced erythropoietin response. Iron stores are preserved, but functionally unavailable. The key to management is treating the underlying condition. For a broader context, see our Blood & Haematology Overview page.