Background The British Society of Rheumatology guidelines for the diagnosis and management of giant cell arteritis (GCA), published in 20101, recommend temporal artery biopsy (TAB) in all suspected cases. Sample length should be over 1cm, with longer samples showing a greater positive predictive value for a positive TAB2.
Objectives To audit these guidelines at JCUH looking at clinical presentation, and details of biopsy sampling.
Methods All TABs in the year 2009-2010 in were identified through pathology records. Information was collated on symptoms, the dose and timing of steroids, TAB length and result. The final diagnosis was also established.
Results 60 TABs were obtained for suspected GCA, mean age 68 years (40 women). For further analysis, the results were separated by TAB result. See table.
All 13 TAB-positive an further 18 TAB-negative patients were treated as GCA.
Non-GCA final diagnoses included: one ANCA positive small vessel vasculitis; one later developed aortitis; 11 other causes of headache; 6 other causes of visual disturbance; 2 malignancies; one TMJ dysfunction; and 7 uncertain diagnoses.
Conclusions 60 TABs were performed with 13 positive results. 31 patients were treated as GCA. ACR classification criteria predicted final diagnosis of GCA with sensitivity 84%, specificity 72%.
TABs were performed rapidly with minimal pre-TAB steroids exposure. Those performed less than 2 weeks after starting steroids had 100% sensitivity for a positive result.
The length of the TAB and the speciality or seniority of the surgeon did not predict a positive result in our sample.
Ophthalmologists seem to have a lower threshold for TAB. The final clinical diagnosis was GCA is only 50% of their patients compared to 80% and 73% of patients seen by rheumatology and general physicians, respectively. Our results would support the use of a rapid access rheumatology-led GCA clinic, where by some unnecessary TABs may be avoided.
Dasgupta B et al. BSR and BHPR guidelines for the management of giant cell Arteritis. Rheumatology (Oxford). 2010 Aug;49(8):1594-7.
Mahr A, Saba M, Kambouchner M et al. Temporal artery biopsy for diagnosing giant cell arteritis: the longer, the better? Ann Rheum Dis 2006;65:826-8.
Disclosure of Interest None Declared