Temporal artery biopsy: are we doing it right?

Temporal artery biopsy (TAB) is the gold standard for diagnosing temporal arteritis; however, sensitivity is relatively poor (30-40 per cent). The British Society of Rheumatology (BSR) guidelines state two major factors that can improve sensitivity: TAB specimen size > 10mm; and pre-biopsy steroid treatment < 7 days. Owing to the low sensitivity, TA treatment is often commenced/continued despite negative histology. The purpose of this paper is to establish the extent to which TAB results influence clinical management and determine specimen adequacy regarding BSR guidelines.

In total, 55 patients underwent TAB between 2009-2011. Patients' medical notes were analysed, specifically looking at biopsy specimen size, histology results and steroid therapy duration, pre- and post-biopsy.

From 55 TABs, three (6 per cent) were positive, 47 (85 per cent) were negative and five (9 per cent) were "inadequate". Of those patients with negative results, 18 (46 per cent) received > six months steroid treatment. From 50 "adequate" specimens, 31 (62 per cent) were < 10mm and 11 (28 per cent) received > seven days steroid treatment pre-biopsy.

Despite negative results, many patients went on to receive long-term steroids. Action must be taken to reduce false and true negative biopsies. False negatives may-be reduced by improving adherence to BSR guidance (increased specimen size and early biopsy after commencing steroids). To reduce total true-negative biopsies, the authors suggest implementing the American College of Rheumatology scoring system, designed to objectify the decision to perform TAB.

This article addresses a common problem seen in most UK hospitals. There is little literature discussing a plausible solution to reducing negative biopsies.