Screening for Latent TB Infection in a Psoriasis Patient with History of BCG Vaccination and Exposure to TB Prior to Treatment with an Anti-TNF-α Agent

Abstract

The treatment of psoriasis has undergone a revolution with the introduction of biologic therapies like anti-tumor necrosis factor-α (TNF-α) antibodies. TNF-α not only plays a major role in the pathogenesis of psoriasis, but also is a key cytokine in the body's defenses against microbacterial infection. In patients with latent tuberculosis (TB), treatment with anti-TNF antibodies may result in the development of active TB. Historically, tuberculin skin tests have been used to detect the presence of latent TB infection. More recently, interferon-gamma release assays have been developed. We report a patient who demonstrates pitfalls of some of our testing for latent TB.