Giant cell arteritis with vertebral artery involvement-baseline characteristics and follow-up of a monocentric patient cohort.

Vertebral artery (VA) involvement in giant cell arteritis (GCA) has rarely been reported. We aimed to evaluate the prevalence, patients' characteristics, and immunotherapies used in patients with GCA and VA involvement at diagnosis and 1 year follow-up, retrospectively including patients being diagnosed between January 2011 and March 2021 in our department. Clinical features, laboratory data, VA imaging, immunotherapy, and 1 year follow-up data were analyzed. Baseline characteristics were compared to GCA patients without VA involvement. Among all 77 cases with GCA, 29 patients (37.7%) had VA involvement, as diagnosed by imaging and/or clinical signs and symptoms. Gender distribution and erythrocyte sedimentation rate (ESR) were significantly different in the groups with and without VA involvement, with more women being affected (38/48 patients, 79.2%) and a significantly higher median ESR in patients without VA involvement (62 vs. 46 mm/h;  = 0.012). MRI and/or CT showed vertebrobasilar stroke at GCA diagnosis in 11 cases. 67/77 patients (87.0%) received high-dose intravenous glucocorticosteroids (GCs) at diagnosis, followed by oral tapering. Six patients were treated with methotrexate (MTX), one with rituximab, and five with tocilizumab (TCZ). 2/5 TCZ patients achieved clinical remission after 1 year, vertebrobasilar stroke within the first year occurred in 2/5 patients. Diagnosis of VA involvement might be underrecognized in GCA patients. VA imaging should be performed in elderly patients with vertebrobasilar stroke presenting with GCA symptoms, not to miss GCA as the etiology of stroke. Efficacy of immunotherapies in GCA with VA affection and long-term outcomes need to be investigated further.