Tuberculosis and anti-TNF treatment: experience of a central London hospital

Reactivation of latent tuberculosis (TB) is an established risk of anti-tumour necrosis factor alpha (anti-TNF) therapy. We report five cases of active TB occurring in 703 patients treated with anti-TNF therapy over a 10-year period in a central London hospital and review our screening practices for identifying latent TB prior to anti-TNF treatment. Four patients were receiving adalimumab and one patient etanercept at the time of TB diagnosis. Four of the five patients were born in countries with a high TB prevalence. Two of the five patients were healthcare workers. All patients had normal chest radiographs prior to anti-TNF treatment. Our data emphasise that country of origin is important in the determining risk of latent TB and that a normal chest radiograph does not exclude latent TB.