Treatment with disease modifying anti-rheumatic drugs (DMARDs) acting as tumour necrosis factor-alpha (TNF) blockers makes IMID patients susceptible to TB [2] due mainly to reactivation of latent TB infection (LTBI), defined as ‘a state of persistent immune responsiveness to Mycobacterium tuberculosis (Mtb) antigens without clinically manifested TB’ [3]. This evidence concerns the gene TNF and tuberculosis.