[Place of azathioprine in the treatment of giant cell arteritis].

OBJECTIVE: The aim of this bicentric retrospective study was to describe the use of azathioprine in giant cell arteritis, and to appreciate its corticosteroid-sparing effect in glucocorticoid-dependent patients or with severe glucocorticoid related side effects.

METHODS: We retrospectively reviewed the medical records of patients diagnosed with giant cell arteritis between 2000 and 2011 in two departments of internal medicine. Only the patients treated with azathioprine were included in this study. Sociodemographic, clinical, biological, radiological and therapeutic data were collected by a standardized questionnaire. A comparative analysis of daily prednisone dose at the initiation and 1 year after the prescription of azathioprine was made.

RESULTS: Of the 28 patients included, 21 responded to azathioprine. At 1 year of follow-up after the initiation of azathioprine, 18 patients (64%) were still in sustained response, asymptomatic, without increase in acute phase response laboratory markers, and with a daily dose of prednisone<10 mg. Three patients (11%) experienced a relapse during azathioprine treatment. Mean daily dose of prednisone were 25.4 mg at the time of initiation of azathioprine, and 4.7 mg at 1 year of treatment, suggesting a corticosteroid-sparing effect (P<0.001). Ten patients experienced azathioprine serious side effects, leading to discontinuation of treatment in seven cases.

CONCLUSION: Azathioprine may be an alternative treatment for patients with giant cell arteritis requiring prolonged high dose glucocorticoid therapy or developing severe glucocorticoid related side effects. However, given the potential adverse effects of azathioprine, a close monitoring is necessary.