Makindo Medical Notes

Related Subjects: | Alpha Thalassaemia | Anaemia of Chronic Disease | Acute Myeloblastic Leukaemia (AML)

💉 Anaemia of Chronic Disease (ACD), also called anaemia of inflammation, is one of the most common anaemias in hospitalised patients. It is characterised by reduced haemoglobin levels despite normal or increased iron stores, due to impaired iron utilisation and blunted erythropoiesis. 📌 ACD typically accompanies chronic infections, autoimmune conditions, malignancy, or renal failure.

🧾 Aetiology

• Chronic inflammation diverts iron into storage sites, limiting its availability for red cell production.
• Inflammatory cytokines (especially IL-6) ↑ hepcidin → blocks ferroportin → ↓ intestinal iron absorption & ↓ iron release from macrophages → "functional iron deficiency".
• Reduced responsiveness to erythropoietin → impaired erythropoiesis.
• Additional factors: erythrophagocytosis, bone marrow infiltration by tumour or infection.

📌 Causes

• Rheumatological: Rheumatoid arthritis, SLE, PMR, vasculitis, sarcoidosis.
• Infective: TB, osteomyelitis, HIV/AIDS, chronic viral, bacterial, fungal, protozoal infections.
• Gastrointestinal: Crohn’s disease, ulcerative colitis.
• Renal: Chronic kidney disease (reduced erythropoietin production).
• Oncological: Solid tumours, haematological malignancies.
• Cardiac: Chronic heart failure, endocarditis.

🧪 Investigations

• FBC: Hb ↓ (usually normocytic/normochromic; can be microcytic), low reticulocyte count.
• Iron studies:
  • Serum iron: ↓ or normal
  • TIBC: ↓ (key discriminator from iron deficiency)
  • Ferritin: normal or ↑ (acute phase reactant)
  • Bone marrow iron: ↑ (stores present but not mobilised)
• Inflammatory markers: ESR and CRP ↑.
• Serum transferrin receptor: Normal (vs ↑ in iron deficiency anaemia).
• Zinc protoporphyrin: ↑ due to impaired haem synthesis.

⚕️ Management

• 1️⃣ Treat underlying cause: Control of infection, autoimmune disease, or malignancy often improves anaemia.
• 2️⃣ Exclude other causes: Always rule out coexistent iron deficiency anaemia.
• 3️⃣ ESAs: Erythropoiesis-stimulating agents (e.g. Epoetin alfa) in CKD or severe cases; usually combined with iron therapy.
• 4️⃣ Parenteral iron: Oral iron often ineffective (blocked absorption); IV iron can help in selected patients despite high ferritin.
• 5️⃣ Blood transfusion: Reserved for severe/symptomatic anaemia (Hb <8–9 g/dL).

📚 References

• Anaemia of chronic disease: A review (2018)
• Anaemia of chronic disease – Clinical Medicine (RCP, 2013)