Efficacy of azathioprine as second-line treatment in pulmonary sarcoidosis

Immunosuppressives such as azathioprine are occasionally used in sarcoidosis where corticosteroids cannot be used because of poor response, contraindications or unacceptable side effects. The aim of this study was to assess the efficacy and safety of azathioprine in the treatment of pulmonary sarcoidosis.

A retrospective study was performed on patients in the Respiratory Clinic of the university teaching hospital on all biopsy-proven sarcoid treated with azathioprine between 1969 and 1993 (n = 10). All had previously shown only partial (n = 6) or no (n = 4) response to high dose oral corticosteroids. Azathioprine in a dose of 100-150 mg was administered daily, while continuing a small dose of oral corticosteroid. Patients underwent regular clinical evaluation, pulmonary function testing and chest radiography.

In one patient the course was too brief to evaluate (26 days). Two patients had significant and sustained improvement in lung function (vital capacity increasing from 72% to 89% and from 49% to 79% of predicted respectively, and transfer factor from 78% to 114% and from 27% to 49% of predicted respectively), and chest radiograph cleared. Two patients had short-lived improvement and steroid-sparing effect. In the remainder (n = 5), no benefit was observed. No patient responded to azathioprine who had failed to respond to high dose corticosteroids. There was no significant toxicity.

Azathioprine may provide a safe alternative to corticosteroids when a steroid-sparing effect is required, but it is unlikely to be effective in patients who fail to respond to high dose corticosteroids and/or have radiographic evidence of significant fibrosis.