Giant cell arteritis in patients with systemic sclerosis: a case series.

OBJECTIVES: Giant cell arteritis (GCA) in patients with systemic sclerosis (SSc) is rare, and optimal treatment strategies for this group of patients have not been defined. We aim to describe the first case series of GCA/SSc overlap.

METHODS: A single-institution retrospective study was performed reviewing all patients that had diagnosis codes for both SSc and GCA between January 1, 1996, and December 31, 2020. Demographic characteristic, clinical presentation, diagnostic modality, treatment, and outcome data were abstracted. Diagnosis of both SSc and GCA by a rheumatologist was required for inclusion.

RESULTS: Eight patients were retrospectively identified, all of which were female. Seven patients fully met both respective ACR/EULAR classification criteria sets. One patient fulfilled GCA criteria and had 8/9 points for SSc criteria plus an oesophagogram which was consistent with clinical diagnosis of SSc. Three patients had a previous history of scleroderma renal crisis (SRC) prior to glucocorticoid initiation for GCA. No episodes of SRC occurred following initiation of glucocorticoids. Three patients were treated with tocilizumab. One patient developed a diverticular perforation while on tocilizumab requiring colonic resection and colostomy, one patient discontinued tocilizumab after a medication-unrelated complication and one patient has remained on treatment and in remission.

CONCLUSIONS: Herein we present the largest single-institution series of patients with a history of GCA and SSc, an uncommon combination. Glucocorticoid treatment for GCA did not precipitate SRC, even in those with prior history of SRC. Further investigation regarding the benefit of tocilizumab in patients with SSc and GCA is required.