Coexistence of sarcoidosis and spondyloarthritis: a rare but intriguing association

We have characterised 23 patients who fulfilled the current classification criteria for both SpA and sarcoidosis. Therefore, sarcoidosis may coexist with SpA like other systemic autoimmune diseases, and this may be explained by shared pathogenic mechanisms. Since Th17 cells are leading actors in the pathogenesis of both SpA and sarcoidosis, these cells may be the missing link connecting the two diseases.