Predictive value of positive temporal artery biopsies in patients with clinically suspected giant cell arteritis considering temporal artery ultrasound findings.

Abstract

To investigate the impact of ocular symptom, non-ocular symptom, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP) and temporal artery ultrasound (TAU) findings on the predictive value of a positive temporal artery biopsy (TAB) in patients with clinically suspected giant cell arteritis (GCA). In a retrospective, interventional study, data from 68 patients with clinically suspected GCA who underwent TAB between 2015 and 2017 were analysed. Analysis included five parameters: ocular symptom, non-ocular symptom, ESR, CRP level and TAU findings. Using a contingency table, each parameter was separately analysed for the predictive value of a positive TAB, and a discriminant analysis was applied to check for the predictive value of a positive TAB under consideration of all five parameters and of the three strongest predictive parameters. A positive TAB was significantly associated with a positive TAU in 15 of 15 patients (p < 0.001), an increased ESR in 37 of 53 patients (p < 0.001), an increased CRP level in 35 of 56 patients (p = 0.004) and non-ocular symptoms in 27 of 40 patients (p = 0.01). A positive TAB was not significantly associated with the presence of ocular symptoms (25 of 46 patients, p = 0.988). Using a discriminant analysis, the combined parameters TAU, ESR and CRP were able to predict a positive TAB in 97.3% of all patients. The positive predictive value was 78.3%, and the negative predictive value was 95.4%. Temporal artery biopsy to confirm the diagnosis of GCA may not be mandatory in patients who show an elevated ESR and CRP level and a positive TAU.