Erythrocyte Sedimentation Rate in Temporal Arteritis

Diagnostic Value of ESR in Temporal Arteritis

The American College of Physicians recommends that ESR values typically exceed 40 mm/h in temporal arteritis, with values above 100 mm/h having the highest specificity (92.2%) for the disease 1
ESR >40 mm/h has high sensitivity (93.2%) for giant cell arteritis with a negative likelihood ratio of 0.18, making it a valuable screening tool 1, 2
ESR >50 mm/h has a sensitivity of 78.9% and specificity of 43.5% for giant cell arteritis 3
ESR >60 mm/h has a sensitivity of 70.7% and specificity of 70.5% with a positive likelihood ratio of 5.77 3
ESR >80 mm/h has a sensitivity of 50.7% and specificity of 81.8% with a positive likelihood ratio of 4.62 3
ESR >100 mm/h has the highest specificity (92.2%) with a positive likelihood ratio of 3.11, making it strongly suggestive of temporal arteritis 1, 3

A normal ESR should raise suspicion for an alternative diagnosis, as raised inflammatory markers are highly sensitive for temporal arteritis 4, 5
Women typically have higher baseline ESR values than men, which should be considered when interpreting results 2

The European League Against Rheumatism recommends that high-dose glucocorticoids should be commenced on strong clinical suspicion of giant cell arteritis, even before biopsy confirmation 4, 5
Temporal artery biopsy remains the gold standard for diagnosis of giant cell arteritis, but should not delay treatment initiation 4, 5
C-reactive protein (CRP) should also be measured, as a normal ESR or CRP should raise suspicion for an alternative diagnosis 4, 5

Anemia and azotemia can artificially elevate ESR values, potentially leading to false positive suspicion for temporal arteritis 2

ESR >50 mm/h has a sensitivity of 87.5% and a negative likelihood ratio of 0.27, making it a valuable screening tool for giant cell arteritis 6

A pretreatment ESR of >50 mm/h has a sensitivity of 87.5% for diagnosing giant cell arteritis 6
Features that should upgrade suspicion for GCA despite a normal or only mildly elevated ESR include jaw claudication 6
Features that should upgrade suspicion for GCA despite a normal or only mildly elevated ESR include limb claudication 6
Features that should upgrade suspicion for GCA despite a normal or only mildly elevated ESR include platelet count >400 × 10³/μL 6
Features that should upgrade suspicion for GCA despite a normal or only mildly elevated ESR include anterior ischemic optic neuropathy 6

ESR is a moderately sensitive but poorly specific test for diagnosing GCA, and should never be used alone to rule in or rule out the disease—an elevated ESR >50 mm/h has 87.5% sensitivity but requires additional clinical features, imaging, or temporal artery biopsy for definitive diagnosis 7

CRP outperforms ESR as a diagnostic marker for GCA, with a sensitivity of 90.1% (95% CI 76.3-96.3%) and a negative likelihood ratio of 0.38 7

Jaw claudication has a positive likelihood ratio of 4.90 for GCA, upgrading suspicion despite normal or low ESR 7
Platelet count >400 × 10³/μL upgrades suspicion of GCA 7
Age ≤70 years has a negative likelihood ratio of 0.48 for GCA, downgrading suspicion 7

The American College of Rheumatology emphasizes that temporal artery biopsy or appropriate imaging (vascular ultrasound, MRI, or PET) remains necessary for definitive diagnosis of GCA 8
Even with highly suggestive clinical features and elevated ESR, histologic or imaging confirmation is required for GCA diagnosis 8

Glucocorticoid treatment should be initiated immediately on strong clinical suspicion of GCA, as treatment can rapidly normalize inflammatory markers and affect biopsy results 9
Pretreatment ESR values showed better sensitivity than post-treatment values for GCA diagnosis 7