Background: Chronic immunosuppression is a known risk factor for allowing latent tuberculosis (TB) infection to transform into active TB. Immunosuppressive/immunomodulatory therapies, while highly efficacious in the treatment of psoriasis and psoriatic arthritis, may be associated with an increased rate of active TB in patients receiving some of these therapies.
Objective: Our aim was to arrive at a consensus on screening for latent TB infection in psoriasis patient treated with systemic and biologic agents.
Methods: Reports in the literature were reviewed regarding immunosuppressive therapies and risk of TB.
Results: Screening patients for latent TB infection before commencement of treatment is of utmost importance when beginning treatment with the tumor necrosis factor-alpha inhibitors, T-cell blockers, cyclosporine, or methotrexate. The currently recommended method for screening is the tuberculin skin test. It is preferable that positively screened patients be treated with a full course of latent TB infection prophylaxis before immunosuppressive/immunomodulatory therapy is initiated. However, in the opinion of many experts, patients may be started on the immunosuppressive/immunomodulatory therapy after 1 to 2 months, if their clinical condition requires, as long as they are strictly adhering to and tolerating their prophylactic regimen.
Limitations: There are few evidence-based studies on screening for latent TB infection in psoriasis patients treated with systemic and biologic agents.
Conclusions: The biologic TNF-alpha inhibitors are very promising in the treatment of psoriasis. However, because TNF-alpha is also an important cytokine in preventing TB infection and in keeping latent TB infection from becoming active disease, the use of TNF-alpha inhibitors has been associated with an increased risk of developing active TB. A higher incidence of TB has also been reported with other immunosuppressive/immunomodulatory treatments for psoriasis. It is, therefore, of utmost importance to appropriately screen all patients for latent TB infection prior to initiating any immunologic therapy. Delaying immunologic therapy until latent TB infection prophylaxis is completed is preferable. However, if the patient is adhering to his prophylactic regimen and is appropriately tolerating the regimen, therapy may be started after 1 to 2 months if the clinical condition requires.