The magnitude of the risk of reactivation of tuberculosis (TB) on use of etanercept, especially in patients with positive purified protein derivative (PPD) test, has not been assessed. We evaluated the risk of developing active TB among PPD-positive patients treated with etanercept.
All patients with a positive PPD test, as defined by American Thoracic Society guidelines, who received etanercept at Cook County Hospital from 2001 to 2008 were retrospectively reviewed. The primary endpoint was the development of active TB either while receiving or after completing etanercept therapy.
Four hundred eighty-seven patients received etanercept, of whom 84 were PPD-positive and constituted the primary cohort. The cohort was composed largely of patients who were at high risk for development of active TB: born in endemic area (80%), ethnic/racial minorities (51 Hispanic, 16 African American, and 8 Asian), and low socioeconomic status (66, 78.57%). Overall etanercept exposure was a mean of 24.6 months (range 3 to 60 mo), with 196 patient-years of etanercept exposure in PPD-positive individuals. Indications for etanercept use included rheumatoid arthritis 58 (69%), ankylosing spondylitis 11 (13%), psoriatic arthritis 13 (15.5%), juvenile inflammatory arthritis 1 (1.2%), and vasculitis 1 (1.2%). Of the 80 subjects, 74 received treatment for latent TB infection (LTBI) prior to initiating etanercept. A comprehensive review of these patients' medical records failed to reveal any active TB infection.
This systematic analysis suggests that the risk of reactivation of LTBI during etanercept therapy is low in appropriately treated individuals.