Sustained drug-free remission in giant cell arteritis.

Objectives: The objectives of this study were to evaluate the frequency and timing of sustained drug-free remission (SDFR) in patients with GCA and to identify potential predictive factors of this outcome.

Methods: A retrospective review of all patients included in the large Spanish multicentre registry for GCA (ARTESER) with at least 2 years of follow-up was undertaken. SDFR was defined as the absence of typical signs, symptoms, or other features of active GCA for ≥12 months after discontinuation of treatment.

Results: We included 872 patients. Forty-seven percent had received concomitant treatment with tocilizumab and/or immunosuppressants, mainly MTX. SDFR was achieved in 21.2% (185/872) of the patients. The cumulative rates of patients achieving SDFR at 2, 3 and 4 years were 6.3%, 20.5% and 25.3%, respectively. Patients who achieved SDFR could reduce their prednisone dosage to 10 mg/day (P = 0.090) and 5 mg/day (P = 0.002) more quickly than those who did not. Relapses were less frequent in patients with SDFR (P = 0.006). The presence of relapses [incident rate ratio (IRR): 0.492, P < 0.001] and the need for i.v. methylprednisolone boluses at diagnosis (IRR: 0.575, P = 0.003) were significantly associated with a decreased likelihood of achieving SDFR. Only 5 patients (2.7%) experienced a recurrence, with a median onset of 19 months after achieving SDFR (interquartile range 25th-75th: 14-35 months).

Conclusion: Within 3-4 years of diagnosis, only one-quarter of patients with GCA successfully reached the SDFR. Once the SDFR was achieved, the likelihood of experiencing recurrence was low. Relapses and the need for glucocorticoid boluses appear to have been predictors of the need for long-term glucocorticoids.