Makindo Medical Notes

Related Subjects: |Ferritin |CEA |ESR |CRP |ALP |LDH |HbA1c |Alpha Fetoprotein |Anti-Hu ab |Biochemical Lab values

The principle of ESR (Erythrocyte Sedimentation Rate) is that during inflammation, acute-phase proteins such as fibrinogen cause red cells to lose their negative surface charge and stick together (rouleaux). Rouleaux are heavier, so they settle faster in a vertical tube. 👉 ESR is non-specific but useful as a broad marker of inflammation, especially in autoimmune and chronic disease.

📖 About ESR

• Measured as the rate (mm/hr) at which erythrocytes fall in a vertical tube.
• Heavily influenced by plasma fibrinogen & immunoglobulins.
• Altered red cell charge promotes rouleaux formation.

📊 Normal Values

• 👨 Males: <15 mm/hr (rises with age)
• 👩 Females: <20 mm/hr (rises with age)

🚩 Causes of Markedly High ESR (>100 mm/hr)

⬇️ Causes of Low ESR

• Polycythaemia (↑ RBC mass = slow settling)
• Sickle cell disease & spherocytosis (abnormal RBC shape prevents rouleaux)
• Extreme leukocytosis (white cell “crowding” slows ESR)
• Acanthocytosis (spiky cells disrupt rouleaux)
• Hypofibrinogenaemia (less acute-phase protein)

⚠️ Limitations & Interpretation

• ESR is non-specific — high in infection, cancer, inflammation.
• Rises with age, pregnancy, anaemia, ↑ immunoglobulins (e.g., myeloma).
• Changes more slowly than CRP → better for chronic rather than acute monitoring.

📊 ESR vs CRP

💡 Clinical Pearls

• ESR >100 mm/hr almost always pathological — think infection, myeloma, vasculitis, or cancer.
• In Giant Cell Arteritis, an ESR >50 is typical — but treat on suspicion, don’t wait.
• Normal ESR does not exclude significant inflammation if fibrinogen is low (e.g., DIC).
• ESR + CRP together: ESR (chronic disease), CRP (acute flare).