Latent tuberculosis infection in psoriasis and other dermatological immunomediated diseases: a combined approach by QuantiFERON-TB Gold and tuberculin skin tests.

n countries of low tuberculosis (TB) prevalence, such asItaly, the widespread use of immunosuppressive drugs andpopulation aging cause an increased risk for progression oflatent tuberculosis infection (LTBI) in active TB. Specifi-cally, the tumor necrosis factor alpha (TNFa) inhibitors,are associated with an increased risk of developing activedisease in patients with LTBI, because TNFa is necessaryfor an effective granulomatous response against Mycobac-terium tuberculosis.1Until a few years ago, the only avail-able assay for the diagnosis of LTBI was the tuberculinskin test (TST).