From the Guidelines
ESR shows the level of inflammation in the body, with elevated levels indicating various inflammatory conditions, including infections, autoimmune disorders, and chronic inflammatory diseases, as seen in a study published in JAMA Internal Medicine in 2020 1. The ESR test measures how quickly red blood cells settle at the bottom of a test tube, with faster settling indicating higher inflammation.
- Normal ESR values are typically 0-15 mm/hr for men and 0-20 mm/hr for women, with values increasing with age.
- Elevated ESR levels can indicate various inflammatory conditions, including:
- Infections
- Autoimmune disorders like rheumatoid arthritis or lupus
- Certain cancers
- Chronic inflammatory diseases However, ESR is non-specific and cannot pinpoint the exact cause of inflammation, so it's usually interpreted alongside other tests and clinical findings, as noted in a study on giant cell arteritis 1. The test works because inflammation causes proteins like fibrinogen to increase in the blood, making red blood cells stick together and settle more quickly.
- ESR results should be monitored over time rather than from a single reading to track disease progression or treatment effectiveness. In the context of giant cell arteritis, an ESR > 40 mm/h had a sensitivity of 93.2% and a specificity of 37.5%, as reported in the 2020 study 1. In another context, such as Kawasaki disease, the ESR is often above 40 mm per hour and can be elevated to levels of at least 100 mm per hour, as noted in a 2006 guideline summary 1.
From the Research
ESR Results
- ESR (erythrocyte sedimentation rate) is a marker of inflammatory conditions 2
- ESR is an indirect measure of fibrinogen, which has a longer half-life than C-reactive protein (CRP), making it helpful in monitoring chronic inflammatory conditions 2
- ESR can be used to monitor chronic inflammatory conditions, whereas CRP is more useful in diagnosis and monitoring responses to therapy in acute inflammatory conditions 2
- Many factors can result in falsely high or low ESR levels, and it is essential to consider these factors when interpreting results 2
ESR and CRP Discordance
- CRP and ESR discordance, where the results differ by 2 or 3 quartiles, occurs in approximately 12% of patients 3
- High CRP/low ESR discordance is more common in patients with infections, particularly in the urinary tract, gastrointestinal tract, lungs, and bloodstream 3
- High ESR/low CRP discordance is more common in patients with connective tissue diseases, such as systemic lupus erythematosus, and ischemic strokes or transient ischemic attacks 3
ESR in Specific Conditions
- ESR is not a specific indicator of a single disease state, but it can be used to gauge disease severity or predict disease progression and outcome 4
- ESR can be elevated in various conditions, including infections, autoimmune diseases, and cancer 5, 6
- In patients with systemic lupus erythematosus, ESR has a sensitivity of 50-69.8% and specificity of 38.5-55.6% for diagnosing infections 5
Comparison with CRP
- CRP is a more sensitive biomarker of inflammation than ESR, but it is not specific to a single disease state 4
- CRP and ESR have different half-lives, with CRP having a shorter half-life, making it more useful for monitoring acute inflammatory conditions 2
- Both CRP and ESR have positive associations with acute and chronic medical conditions, but elevated ESR is seen more frequently in acute medical conditions 6