Tumour necrosis factor (TNF)-a antagonists, such as infliximab, adalimumab and etanercept, are widely used to treat immune-mediated inflammatory diseases. These drugs increase the risk of latent infection with Mycobacterium tuberculosis (LTBI) reactivation [1, 2]. Tuberculosis (TB) preventative chemotherapy significantly reduces this risk (74%); hence, in the UK, patients are screened for LTBI ...