Lung sarcoidosis induced by TNF antagonists in rheumatoid arthritis: a case presentation and a literature review.

We report on a 72 year-old woman with long-standing rheumatoid arthritis diagnosed as granulomatosis due to pulmonary sarcoidosis after 49 months of treatment with etanercept. A clinical and radiological improvement was seen after tumor necrosis factor (TNF) antagonist withdrawal plus a course of steroids. Currently, 27 cases of histological proven sarcoidosis with pulmonary involvement have been reported in relation to anti-TNF therapy, with etanercept being more frequent in comparison with the anti-TNF monoclonal antibodies infliximab and adalimumab. Potential pathogenic mechanisms of the paradoxical effect of anti-TNF treatment is discussed. It is important for clinicians to be aware of this potential and uncommon complication of biological therapy with TNF antagonists.