Characteristics of patients with major relapse in giant cell arteritis: a multicenter case-control study

The objective was to identify predictive factors for major relapses (MR) in patients with giant cell arteritis (GCA) and to compare clinical characteristics between MR phenotypes.

This multicenter retrospective case-control study included patients fulfilling GiaCTA criteria for GCA. Cases were patients experiencing MR according to 2018 EULAR definitions. Controls were GCA patients without MR with a 1:3 ratio. Data were collected and analyzed using univariate and multivariate logistic regression to determine factors independently associated with MR. MR was subclassified into cranial-MR and large-vessel-MR which were compared using appropriate statistical tests.

258 patients were included, 70 cases and 188 controls (48.4% minor relapse, and 24.4% without relapse). The mean age at diagnosis was 72.5 ± 8.6 years, 70,9% were females. Younger age at diagnosis was associated with an increased risk of MR (OR = 0.93 per 10 years, 95% CI [0.87; 0.999], p = 0.043). No other clinically significant risk factors were identified. Among the 70 cases, 48.6% had a cranial-MR and 51.4% a large-vessel-MR. Patients with a cranial-MR were older (74.3 ± 6.3 years vs. 67.3 ± 7.0 years, p < 0.001) and were more likely to have cranial symptoms at diagnosis of GCA (91.2% vs. 69.4%, p = 0.023) compared to those with a large-vessel-MR. Compared with cranial-MR, large-vessel MR was more frequent in women (80.5% vs. 52.9%, p < 0.01) and tended to be associated with aortitis at diagnosis (70.0% vs. 43.5%, p = 0.052).

Younger age at diagnosis was the only independent predictor of MR. Relapse patterns mirrored initial disease phenotype, supporting the existence of cranial and large-vessel GCA subtypes. Key Points •Younger age at diagnosis is associated with a higher risk of major relapse in giant cell arteritis. •Cranial and large-vessel major relapses display distinct clinical patterns, often mirroring the initial disease phenotype. •No strong laboratory or imaging predictor of major relapse was identified in this multicentre case-control study.