Development of sarcoidosis following etanercept treatment: a report of three cases.

After over 10 years of use of tumor necrosis factor-alpha (TNF-α) inhibitors, their side effects and complications are reasonably well documented. Recently, however, granulomatous reactions and cases of complete sarcoidosis have been reported, especially in patients treated with the TNF-α receptor protein, etanercept. This is intriguing because the TNF-α antibody drugs infliximab and adalimumab are reportedly used to treat sarcoidosis. We present three patients who developed sarcoidosis while on etanercept treatment, and discuss if possible differences in cytokine profiles and T regulatory cell function in patients taking different TNF-α inhibitors may explain this paradox.