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 the 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.