Erythrocyte Sedimentation Rate (ESR)

An erythrocyte sedimentation rate (ESR) test is sometimes called a sedimentation rate test or sed rate test. This blood test doesn’t diagnose one specific condition. Instead, it helps your healthcare provider determine whether you’re experiencing inflammation.

Also Known As:  Sed Rate, Sedimentation Rate, Westergren Sedimentation Rate, Wintrobe Sedimentation Rate, Erythrocyte Sedimentation Rate , ESR

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Test Panel: Hemoglobin, Red Blood Cells (RBC), HCT, MCV, MCH, MCHC, Platelets Count, White Blood Cells (WBC), DLC, ESR

Why get Tested:

1. It can be done in the occult diseases.
2. For the diagnosis of acute and chronic infections.
3. For collagen vascular diseases.
4. In advanced malignancies.
5. In tissue necrosis and infarction.
6. ESR can be used to monitor disease therapy, especially for autoimmune diseases. It will correlate with the severity of the disease or with the improvement in the disease course.
7. It is useful for the diagnosis and monitoring of temporal arteritis, and polymyalgia rheumatica.
8. It is also used for monitoring of the Hodgkin’s lymphoma.

When to get Tested:

• When your health practitioner thinks that you might have a condition causing inflammation;
• when you have signs and symptoms associated with temporal arteritis,
• when you have signs and symptoms associated with systemic vasculitis,
• when you have signs and symptoms associated with polymyalgia rheumatica, or
• when you have signs and symptoms associated with rheumatoid arthritis such as headaches, neck or shoulder pain, pelvic pain, anemia, poor appetite,
• when you have signs and symptoms associated with unexplained weight loss,
• when you have signs and symptoms associated with joint stiffness

Sample Required:

• The whole blood sample is taken in the EDTA (anticoagulant). It measures the rate of sedimentation in one hour.
• The sample is stable for 2 hours at 25 °C and 12 hours at 4 °C.

Factors affecting ESR:

1. RBCs factors:
   1. In case of absence of rouleaux formation, it will lead to a low ESR level conditions are like:
      1. Sickle cell anemia.
      2. Spherocytosis.
      3. Acanthocytosis.
2. Plasma factors:
   1. In the case of increased protein will lead to increased rouleaux formation and increased ESR like:
      1. Fibrinogen.
      2. Immunoglobulins.
3. Mechanical factors:
   1. It depends upon the caliber of the test tubes, like Wintrobe tubes range from 0 to 100 mm and has different values as a comparison to the Westergreen method.
4. Anticoagulants factors:
   1. Sodium citrate and EDTA have no effect on the ESR.
   2. Sodium or potassium oxalate shrinks the RBCs.
   3. Heparin also causes shrinkage of the RBCs and gives rise to increased false ESR value.
   4. So EDTA is the choice of anticoagulant.

Referance Ranges:

There are conditions where ESR is not raised:

1. polycythemia.
2. sickle cell anemia
3. Spherocytosis.
4. Hypofibrinogenemia.

Causes of raised ESR:

1. Bacterial infections in the abdomen, pelvic inflammatory disease, syphilis, and pneumonia.
2. Chronic renal diseases.
3. Malignant diseases like Multiple myelomas, Hodgkin’s disease, and advanced carcinomas.
4. Inflammatory diseases like temporal arteritis, rheumatoid arthritis, rheumatic fever, and systemic lupus erythematosus.
5. Necrotic diseases like Acute myocardial infarction, gangrene, and necrotic tumors.
6. Tuberculosis.
7. Severe anemia like iron deficiency, and B12 deficiency.

Falsely lowered ESR level:

1. Sickle cell anemia.
2. Spherocytosis.
3. Hypofibrinogenemia.
4. Polycythemia.

ESR is a nonspecific test but this is one of the best tests to find any kind of abnormality in the body. Whenever you find raised ESR, never ignore it but have a thorough workup of the patients.

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