TNF and inflammatory bowel disease: Immunosuppressive and biologic therapies (steroids, immunomodulators, including thiopurines and methotrexate, and monoclonal antibodies to tumor necrosis factor (TNF)-alpha) [107,108] have transformed the management of IBD but, at the same time, their use is associated with a lower probability of response to recombinant hepatitis B vaccine [107].