[TNF-alpha Inhibitor-Induced Pulmonary Sarcoidosis]

TNF-alpha inhibtors represent an established option for autoimmune disorders such as rheumatoid arthritis, psoriasis and chronic-inflammatory bowel diseases as well as for granulomatous diseases including sarcoidosis. Their primary mode of action is antagonistic, blocking the interaction of TNF-alpha with its receptors TNFR1 and TNFR2. Currently five TNF-alpha inhibitors are clinically used: infliximab, adalimumab, golimumab, certolizumab and etanercept.In rare cases TNF-alpha inhibitors may induce sarcoidosis through a paradoxical reaction. This phenomenon is observed most frequently during treatment with etanercept, although the underlying mechanisms remain unclear. The clinical presentation of TNF-alpha inhibitor-induced sarcoidosis closely resembles that of idiopathic sarcoidosis and is characterized by a heterogeneous, inflammatory and granulomatous disease pattern with affection of multiple organ systems. Depending on the causative active agent, a differing distribution of clinical manifestations may occur.From a diagnostic perspective, laboratory analyses and the histological confirmation of the affected organ demonstrating epithelioid cell granulomas are essential. The cornerstone of therapy is the immediate discontinuation of the triggering TNF-α inhibitor. In selected cases, adjunctive systemic corticosteroid therapy may be considered. With timely recognition and appropriate management, the prognosis is generally favourable.