Sedimentation Rates & Polyarthritis

Sedimentation rates help physicians identify causes of polyarthritis, defined by Dorland's Medical Dictionary as "arthritis involving more than one joint." Sedimentation rates can also help determine effectiveness of treatments already underway for potentially debilitating conditions like rheumatoid arthritis.

Sedimentation Rate

• After drawing the patient's blood, the laboratory technician places the blood into a prepared test tube and monitors how far the red blood cells (erythrocytes) fall in the tube over one hour. While frequently called a sedimentation rate, it is more accurately an erythrocyte sedimentation rate, or ESR.

Significance

• According to the Mayo Clinic, inflammation alters proteins in the blood, which causes red blood cells to clump together and become heavier. Thus, the farther or faster the red blood cells fall in the tube can determine levels of inflammation in the body.

Inflammation and Polyarthritis

• Immunologic conditions that cause polyarthritis, like rheumatoid arthritis, may result in significant inflammation as they attack joint tissue. When a patient presents with symptoms of polyarthritis, WebMD notes that doctors often choose to measure ESR to help identify whether an immunologic disorder is at work.

Monitoring Treatment and Progression

• Some medications used to treat polyarthritis, like corticosteroids, act by reducing inflammation. Your physician may order routine monitoring of ESR to check responses to medication or if your disease is progressing, as evidenced by rising ESR.

Limitations

• The Mayo Clinic notes that ESR testing is not as specific in measuring inflammation as other diagnostic tools available to physicians and so is not used as frequently in 2010 as in the past to measure inflammation.