Synonyms

• Erythrocyte Sedimentation Rate
• ESR
• Westergren Sedimentation Rate

Use

Evaluate the nonspecific activity of infections, inflammatory states, autoimmune disorders, and plasma cell dyscrasias.

Limitations

The ESR is of limited diagnostic value in severe anemia or in hematologic states that affect increased size and shape variation (poikilocytosis) of the RBC (ie, presence of sickle cells or spherocytes). Extreme plasma viscosity will result in a decreased ESR.

Elevations in fibrinogen, α- and β-globulins (acute phase reactants), and immunoglobulins increase the sedimentation rate of red cells through plasma. The test is important in the diagnosis of temporal arteritis, as well as its management.