Background/Purpose: In spite of the satisfactory initial response to glucocorticoid treatment, patients with giant cell arteritis (GCA) frequently experience relapses during follow-up. The objectives of this study were 1) To investigate the prevalence and characteristics of relapses in a prospectively followed cohort of patients with GCA. 2) To determine whether clinical or analytical findings at presentation may predict relapses and 3) To analyze whether a relapsing course is associated with higher cumulated GC doses and more prolonged treatment periods.

Methods: Between 1995 and 2007, 187 patients were diagnosed with biopsy-proven GCA at our institution. Among them, 106 patients fulfilled the following inclusion criteria: prospective treatment by the authors according to uniform criteria and prospective follow-up for at least 4 years. GCA features and blood tests at diagnosis (acute phase reactants, blood cell counts and liver function tests), ischemic complications, relapses, and prednisone doses for at least 4 years. Relapses were defined as reappearance of disease related symptoms accompanied by elevation of acute-phase reactants that required treatment adjustment. Type of relapse was defined as PMR, cranial symptoms, severe cranial ischemic complications or systemic disease (anemia, fever and/or weight loss). Chi-square test, student T test and Kaplan-Meyer survival analysis/log-rank test were used for statistical comparison. 

Results: During the follow-up period (mean 7.6 ± 3.3 years), 66 (62%) patients experienced at least 1 relapse and 38 (36%) 2 or more. Relapses consisted of PMR in 33 (50%), cranial symptoms in 19 (29%), systemic complaints in 13 (19.5%) and cranial ischemic complications in 1 (1.5%). Mean time (in weeks) to first relapse was 72 ± 71 (11-339). There were no differences in clinical findings or blood test results at presentation between patients who relapsed and those who achieved sustained remission. However, 23 (60.5%) of patients with ≥ 2 relapses had a strong systemic inflammatory response at presentation (defined as at least 3 of the following fever >38^oC, weight loss >5 kg, hemoglobin < 11 gr/L or ESR >85 mm/hour) which was present in only 5 (18%) of the remaining patients (p=0.001). Patients with ≥ 2 relapses presented significantly higher levels of ESR and C-reactive protein at 6 months and lower concentrations of hemoglobin at baseline, at 6 months (all p<0.01) and at 24 months (p=0.045). Patients with relapses required longer periods of time to reach a stable maintenance dose of prednisone <10mg/day (67±58 weeks vs 31±21, p<0.001), <5mg/day (159±106 vs 89±42, p<0.001) and to completely discontinue GC treatment (237±124 vs 157±59 p=0.005). In addition, cumulative prednisone dose at one year was significantly different between both groups (6.2±1.7 gr vs 5.4±0.7, p=0.01).

Conclusion: More than 60% of patients with GCA experience at least one relapse and 36% have multiple relapses. Relapses usually consist of PMR. Those with multiple relapses have stronger systemic inflammatory response at presentation. A relapsing course is associated with higher and prolonged GC requirements underlining the need for more effective treatments for GCA.

Supported by SAF 08/04328, SAF 11/30073, CONACYT and AGAUR

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ACR Meeting Abstracts - https://acrabstracts.org/abstract/relapses-in-patients-with-giant-cell-arteritis-prevalence-characteristics-and-associated-clinical-findings-in-a-prospectively-followed-cohort-of-106-patients/