Incidence of tuberculosis infection in psoriatic patients on anti-TNF therapy: report of a case series with 144 patients.

BACKGROUND: Worldwide clinical trials and post-marketing surveillance data have demonstrated an increased incidence of tuberculosis (TB) disease associated with antitumour necrosis factor (anti-TNF) agents. The majority of these cases are presumed to result from a reactivation of latent disease, while the rate of new infections is unknown. A study was performed to evaluate th incidence of latent tuberculosis infection (LTBI) in psoriatic patients screened for biological therapy in a high-incidence area, such as Madrid, Spain. PATIENTS AND METHODS: One hundred and forty-four patients with moderate-to-severe psoriasis treated with anti-TNF agents were recruited. All of them were screened for active TB or LTBI before therapy. The screening included a detailed medical study, physical examination, chest X-ray, tuberculin skin test (TST) with purified protein derivative and re-TST.
RESULTS: A total of 42 (29%) patients were diagnosed with LTBI based on a positive TST or re-TST, and/or signs of past TB in the chest X-ray. All of them received chemoprophylaxis with isoniazide. One patient developed a primary active lymphnode TB.
CONCLUSION: This is the first study to underscore the incidence of LTBI in patients with psoriasis treated with anti-TNF therapy in the Spanish population. We support that the use of TST is still reliable and an effective diagnostic method for the detection of LTBI in anti-TNF therapy.