Study Identifies Factors That Could Help Diagnose Giant Cell Arteritis

By Joe Elia

Edited by David G. Fairchild, MD, MPH, and Jaye Elizabeth Hefner, MD

A meta-analysis seeks to rank the likelihood that tests for giant cell arteritis (GCA) will lead to an accurate diagnosis — or lower suspicion of the condition. The analysis appears in JAMA Internal Medicine.

In some 70 studies encompassing over 14,000 patients with suspected GCA, the findings with positive likelihood ratios rated as significant included limb claudication (6.0); jaw claudication (4.9); temporal artery thickening on biopsy (4.7) or loss of pulse (3.3); platelet counts above 400,000 per microliter (3.8); temporal tenderness (3.1); and erythrocyte sedimentation rates above 100 mm/h (3.1).

Suspicion-lowering findings included the absence of sedimentation rates above 40; absence of C-reactive protein levels of 2.5 mg/dL or higher; and age under 70.

A commentator affirms that there is no "gold standard" test for the condition, observing, "When there is no gold, clinicians engage in alchemy. That alchemy is the clinical diagnosis."