TNF and ankylosing spondylitis: In this scene HI has to be considered in every immunosuppressed patient, especially when, nowadays, more than 400 000 patients with RA, inflammatory bowel disease, psoriatic arthritis, and ankylosing spondylitis are treated with anti-TNFα therapy and since its approval by FDA worries related to its safety appeared, mainly related to reactivation of granulomatous diseases (tuberculosis) [2].