Lab

Erythrocyte Sedimentation Rate

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Erythrocyte Sedimentation Rate, ESR

  • Mechanism
  1. Acute phase reactants in blood
    1. Nonspecifically bind to Red Blood Cells
    2. Increases sedimentation rate
  2. Measures settling rate of anticoagulated erythrocytes
    1. Height of RBCs that settle in tube within 1 hour
  3. Marker of tissue inflammation
    1. High Test Sensitivity
    2. Low Test Specificity
  4. Dynamics of sedimentation rate
    1. Rises >24 hours after inflammation onset and symptoms
    2. Gradually returns to normal 4 weeks after resolution
  • Interpretation
  • Normal
  1. Newborn: 0-2 mm/hour
  2. Children: 3-13 mm/hour
  3. Women
    1. Range for ages 18 to 50 years: 1-20 mm/hour
    2. Range for age over 50 years: 1-30 mm/hour
    3. Normal Maximum: (Age in years + 10) / 2
  4. Men
    1. Range for ages 18 to 50 years: 1-15 mm/hour
    2. Range for age over 50 years: 1-20 mm/hour
    3. Normal Maximum: (Age in years) / 2
  • Indications
  1. Grades acute illness severity in Emergency Setting
    1. 299 Peds patients with Limp, Abdominal Pain, Fever
      1. ESR >50 (n=101): 56% had significant illness
      2. ESR 20-50 (n=109): 27% had significant illness
      3. ESR <20 (n=89): 8% had significant illness
    2. Where significant illness
      1. Rheumatoid Arthritis
      2. Osteomyelitis
      3. Pneumonia
      4. Pyelonephritis
    3. Reference
      1. Huttenlocher (1997) Clin Pediatr 339-44 [PubMed]
  2. Diagnosis of Rheumatic Conditions
    1. Polymyalgia Rheumatica (Test Sensitivity: 80%)
    2. Temporal Arteritis (Test Sensitivity: 95%)
  3. Staging of condition
    1. Rheumatic conditions with waxing and waning course
    2. Rheumatoid Arthritis
  • Causes
  • Falsely decreased ESR (interfere with rouleaux formation)
  1. Severe Leukocytosis
  2. Red Blood Cell abnormalities
    1. Acanthocytosis (crenated RBCs that are shrunk and notched, such as when in hypertonic solution)
    2. Poikilocytosis
    3. Anisocytosis (unequal sized RBCs)
    4. Spherocytosis
    5. Sickle Cell Disease
    6. Microcytosis (e.g. Iron Deficiency Anemia)
    7. Polycythemia
  3. Protein abnormalities
    1. Hypofibrinogenemia
    2. Hypogammaglobulinemia
    3. Macroglobulinemia or other dysproteinemia (e.g. Hyperviscosity Syndrome)
  4. Lab error
    1. Clotted blood sample
    2. Tube vibration during measurement
    3. Short tube
    4. Inadequate mixing of sample
    5. Dilution problem
  • Causes
  • Increased ESR due to miscellaneous factors
  1. Older age (increased Fibrinogen level)
  2. Female gender
  3. Pregnancy
  4. Lab error (e.g. dilution error, tube tilted during measurement, increased Temperature of specimen)
  • Causes
  • Increased ESR in Infectious Disease
  1. Bacterial Infections
  2. Infectious hepatitis
  3. Cat Scratch Disease
  4. Post-perfusion syndrome
  5. Primary Atypical Pneumonia
  6. Tuberculosis
  7. Secondary Syphilis
  8. Leptospirosis
  9. Systemic Fungal Infection
  • Causes
  • Increased ESR in Hematologic and Neoplastic Disease
  1. Severe Anemia or macrocytosis
  2. Leukemia
  3. Lymphoma
  4. Metastatic tumor
  5. Chronic granulomatous disease
  6. Increased Fibrinogen level
  • Causes
  • Increased ESR in Gastrointestinal Disease
  • Causes
  • Increased ESR in Collagen Vascular Disease
  • Causes
  • Increased ESR in Miscellaneous disorders
  1. Hypothyroidism
  2. Thyroiditis
  3. Sarcoidosis
  4. Infantile cortical hyperostosis
  5. Trauma from surgery or Burn Injury
  6. Drug Hypersensitivity Reaction