Screening for latent tuberculosis before tumour necrosis factor antagonist therapy

We read with great interest the recent letter by Woodfield et al. [1]. The authors report a retrospective study evaluating the use of either an interferon- gamma release assay (IGRA) result or a chest radiograph, alone, as a screening approach for identifying patients with latent tuberculosis (TB) infection (LTBI) before initiating tumour necrosis factor (TNF)- alpha antagonist therapy. In this study, 353 IGRA-negative patients were commenced on TNF- alpha antagonists for a variety of inflammatory conditions without further LTBI assessment; one patient subsequently developed active TB.