What is the positive yield of temporal artery biopsies for giant cell arteritis

What is it about?

Giant cell arteritis is an inflammation of the arteries in patients 50 years of age or older. The inflammation can cause blindness, and occasionally weakness of the aortic wall and stroke. The symptoms and signs of giant cell arteritis can overlap with other diseases, and the treatment of giant cell arteritis requires steroids, which have potential side effects. As such temporal artery biopsy is performed to confirm the diagnosis of giant cell arteritis. We wanted to determine what percentage of temporal artery biopsies performed were positive for the diagnosis of giant cell arteritis (utility rate). Note that the utility rate of a pathology series differs from the sensitivity of temporal artery biopsy for giant cell arteritis. We found the yield was highly variable in 133 different studies, but the median yield was 25%, with results between 17% to 34% to be in a `reasonable range`. Because the results were so variable, meta-analysis was not performed.

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Photo by National Cancer Institute on Unsplash

Photo by National Cancer Institute on Unsplash

Why is it important?

The median utility rate provides a benchmark for centres that perform temporal artery biopsy. The median utility can be used when comparing temporal artery biopsies (the current gold standard test for giant cell arteritis) to alternative investigation techniques such as ultrasound.