Relapses and long-term remission in large vessel giant cell arteritis in northern Italy: Characteristics and predictors in a long-term follow-up study

Objective: To evaluate characteristics and predictors of relapses and long-term remission in an Italian cohort of patients with large-vessel (LV) giant cell arteritis (GCA). Methods: We evaluated 87 consecutive patients with LV-GCA followed up at the Rheumatology Unit of Reggio Emilia Hospital (Italy) for at least 2 years. Patients with relapses and long-term remission were compared to those without. A group of 34 patients with biopsy proven GCA without LV vasculitis (LVV) at diagnosis was considered for comparison. Patients: 37 patients (42.5%) experienced one or more relapses. Nineteen (37.2%) of the 51 relapses were experienced during the first year after diagnosis. The majority of relapses occurred with doses of prednisone (PDN) ≤ 10 mg/day (74.5%). Polymyalgia rheumatica (PMR) (41.2%) and worsening at imaging of LVV (39.2%) were the most frequently observed relapsing manifestations. The total cumulative prednisone dose was significantly higher (p < 0.0001) and the total duration of PDN treatment longer (p < 0.0001) in relapsing patients compared to those without relapses. Relapsing patients had at diagnosis more frequently fever ≥ 38°C (p = 0.03) and visual manifestations (p = 0.03), and less frequently long-term remission (p = 0.002). In the multivariate model fever ≥ 38°C (HR 2.30, 95%CI:1.11-4.78) and total cumulative PDN dose (HR 1.18, 95%CI: 1.08-1.30) were significantly associated with an increased risk of relapses, while aortic arch involvement at imaging at diagnosis (HR 0.26, 95%CI: 0.11-0.59) and long-term remission (HR 0.27, 95%CI: 0.11-0.65) with a reduced risk. 35/84 patients (41.6%) experienced long-term remission. PMR and disease relapses were less frequently observed (p = 0.04 and p = 0.002, respectively), and the total cumulative prednisone dose was lower (p < 0.001) in patients with long-term remission compared to those without. In the multivariate model the presence of relapses (HR 0.21, 95%CI: 0.07-0.62) and the total cumulative PDN dose (HR 0.85, 95%CI: 0.77-0.95) were significantly negatively associated with long-term remission. Conclusion: In our cohort of patients with LV GCA we identified predictors of a relapsing course and long-term remission, which were observed in around half of the patients.