External validation of giant cell arteritis (GCA) criteria : focus on new 2021 ACR-EULAR criteria for GCA

Abstract

Giant cell arteritis (GCA) is a diverse disease that affects large vessel and cranial arteries. The most scared complication is loss of vision. The best way to prevent this is fast diagnosis. American College of Rheumatology (ACR) authored the first classification criteria in 1990. More recent criteria and probability scores have been developed. 2021 ACR and European Alliance of Association for Rheumatology (EULAR) is the most recent classification criteria for GCA. Southend probability score (GCAPS) made by Laskou et al. in 2019 is a proposal to assess the probability of the disease. In this study we compare these criteria and probability score against the final diagnosis.

We searched and manually collected data retrospectively from patient information system that had three or more GCA diagnosis (ICD-10 codes M31.5 or M31.6). Patients were evaluated by two experienced rheumatologists.

140 patients were included to final study. The original criteria by ACR had the lowest sensitivity of the three 85.0 %. ACR-EULAR 2022 criteria had the highest at 97.9% and GCAPS also performed well at 96.4%. Only one patient had negative result in all three groups. The lack of diagnostic criteria of GCA has inflicted the use of the classification criteria on clinical purpose. The more recent criteria and probability score are showing promising results. More validation needs to be done to refine and better the diagnostic result.