Inflammatory Markers Definition

Inflammatory markers are signs of body-wide inflammation. Lab tests for inflammatory markers require blood samples.

The two most common tests for inflammatory markers are:

  • C-reactive protein (CRP) test. This test looks for specific protein molecules, called C-reactive proteins, in the blood. The more CRP present, the more active inflammation is in the body.
  • Erythrocyte sedimentation rate (ESR) test. This test measures how fast red blood cells settle to the bottom of a test tube (while other parts of the blood, including white blood cells and plasma, move to the top). When the rate is faster than normal, the ESR rate is high and inflammation is active.

Some inflammatory markers that can be found in the blood are linked to particular diseases. For example, if rheumatoid factor (RF) proteins and anti-CCP antibodies are associated with rheumatoid arthritis, and antinuclear antibodies (ANA) are associated with systemic lupus erythematosus (SLE).

Just having a certain inflammatory marker is not enough to diagnose a disease—other signs and symptoms must be present. In addition, inflammatory markers are not always related to autoimmune diseases. They can be signs of other diseases or infections.

Once a disease is diagnosed, an inflammatory marker test(s) may be used to help monitor the inflammation. For example, a person with rheumatoid arthritis may undergo lab testing to measure C-reactive proteins every 3 to 6 months to help determine if treatment is working.