From the Guidelines
An elevated sedimentation rate (sed rate or ESR) denotes inflammation in the body, which can be caused by various conditions such as infections, autoimmune disorders, or inflammatory diseases, as indicated by studies like 1 and 1. This blood test measures how quickly red blood cells settle to the bottom of a test tube, with faster settling indicating higher inflammation levels.
- Normal values are typically below 20 mm/hr for men and below 30 mm/hr for women, though these ranges vary by age.
- An elevated sed rate is not specific to any particular condition but serves as a general marker that inflammation is present somewhere in the body.
- Common causes include infections, autoimmune disorders (like rheumatoid arthritis or lupus), certain cancers, and inflammatory conditions. The test is useful for monitoring disease activity and response to treatment in inflammatory conditions, but it should always be interpreted alongside clinical symptoms and other laboratory findings since it cannot pinpoint the exact location or cause of inflammation, as noted in 1. The mechanism behind an elevated sed rate involves inflammatory proteins like fibrinogen causing red blood cells to stick together and settle more quickly in the test tube. In the context of diagnosing conditions like osteomyelitis, a markedly elevated serum inflammatory marker, especially erythrocyte sedimentation rate, is suggestive of the disease, as mentioned in 1. However, a definite diagnosis usually requires positive results on microbiological examinations of an aseptically obtained bone sample. It's essential to consider the clinical context and use the sed rate in conjunction with other diagnostic tests to determine the underlying cause of inflammation, as recommended in studies such as 1 and 1.
From the Research
Elevated Sed Rate Denotes
- Elevated sed rate, also known as erythrocyte sedimentation rate (ESR), is a laboratory marker of systemic inflammation 2, 3, 4
- It measures the rate at which erythrocytes (red blood cells) settle in a test tube containing a blood sample 2
- An elevated ESR indicates the presence of inflammation in the body, which can be caused by various conditions such as malignancy, autoimmune disease, or infection 2, 3, 4
- ESR measurements can be affected by various factors, including noninfectious conditions and resolution of inflammation, which can lead to discrepancies between ESR and C-reactive protein (CRP) measurements 3
- The diagnostic accuracy of ESR in acute inflammation is similar to that of CRP, with a sensitivity of 0.78 and specificity of 0.68 for orthopedic infections 4
- The combined use of ESR and CRP can yield higher diagnostic accuracy in assessing inflammation 4
Clinical Relevance
- ESR and CRP are widely used laboratory markers of systemic inflammation, but they lack sensitivity and specificity, and should be used only in combination with clinical history and physical exam for diagnosis and monitoring of pathological conditions 3
- ESR measurements by TEST 1 reflect inflammation better than those by the Westergren method in patients with malignancy, autoimmune disease, or infection 2
- Discordance between ESR and CRP measurements can occur in certain settings, such as chronic inflammatory diseases, and can be caused by various physiological factors 3