Makindo Medical Notes

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

In midst of attack
Hepcidin holds iron back
Price of war effort
Red cells right size, numbers lack
Quell the fire, marrow snaps back
@DrCindyCooper

About Anaemia of Chronic Disease

Anaemia of chronic disease (ACD), also known as anaemia of inflammation, is a common type of anaemia that occurs in chronic infections, inflammatory diseases, or malignancies. It is characterized by reduced haemoglobin levels despite normal iron stores and haematinics. ACD is often associated with an underlying systemic process affecting haematopoiesis.

Aetiology

• Chronic inflammation leads to diversion of iron from circulation into storage sites, diminishing availability for erythropoiesis.
• There is a blunted response to erythropoietin, leading to decreased red blood cell (RBC) production.
• Inflammatory cytokines, especially interleukin-6 (IL-6), increase hepcidin production.
• Hepcidin binds to ferroportin, blocking iron export from macrophages and hepatocytes, and downregulates iron absorption in the duodenum, causing 'functional iron deficiency'.
• Erythrophagocytosis and bone marrow invasion by tumour cells or pathogens can also contribute.

Causes

• Rheumatological Diseases: Rheumatoid arthritis (RA), Systemic Lupus Erythematosus (SLE), Polymyalgia Rheumatica (PMR), Vasculitis, Sarcoidosis.
• Infections: Tuberculosis (TB), Osteomyelitis, HIV/AIDS, chronic viral, bacterial, protozoal, and fungal infections.
• Inflammatory Bowel Disease: Crohn's disease, Ulcerative colitis.
• Chronic Renal Failure
• Malignancies: Solid tumours, Haematological malignancies.
• Cardiac Conditions: Endocarditis, Chronic heart failure.

Investigations

• Full Blood Count (FBC): Low haemoglobin (Hb), usually normocytic and normochromic anaemia, but may be microcytic; low reticulocyte count.
• Iron Studies:
  • Low or normal serum iron.
  • Low total iron-binding capacity (TIBC).
  • Normal or increased ferritin (an acute-phase reactant).
  • Increased iron stores in bone marrow.
• Inflammatory Markers: Elevated C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR).
• Serum Transferrin Receptor Assay: Remains normal in ACD but elevated in iron deficiency anaemia; helps differentiate between the two.
• Zinc Protoporphyrin Levels: May be increased due to impaired haem synthesis.

Management

• Treat Underlying Cause: Addressing the primary disease can improve anaemia.
• Exclude Other Causes: Important to rule out iron deficiency and other types of anaemia.
• Erythropoiesis-Stimulating Agents (ESAs): Considered in cases of chronic kidney disease or when anaemia is severe; often combined with iron therapy.
• Parenteral Iron Therapy: May be beneficial as oral iron is often ineffective due to hepcidin-mediated absorption blockade; however, ferritin levels may not predict response.
• Blood Transfusion: Reserved for patients with severe anaemia (Hb < 8-9 g/dL) or symptomatic patients.

References

• Anaemia of chronic disease: A review
• Anaemia of chronic disease (2013)