To the Editor
Patients who are treated with anti-tumor necrosis factor-α (anti-TNF-α) blockers are at risk of reactivation of latent tuberculosis (TB) infection (LTBI). The study by Dr. Malaviya, et al describes an approach to the diagnosis of LTBI prior to anti-TNF-α therapy1. Screening tests they advise are tuberculin skin test (TST), interferon-γ release assay, or Quantiferon TB Gold (QTB Gold), chest radiograph (CXR), and computed tomogram (CT) of the thorax. We describe 2 patients who developed active TB while taking infliximab, despite the recommended screening tests being negative.
Case 1: In March 2009, A 30-year-old male, with long standing ankylosing spondylitis (AS), complained of worsening of axial symptoms in spite of adequate nonsteroidal antiinflammatory drugs (NSAID). As the AS was active, infliximab therapy was offered. Baseline laboratory findings were: hemoglobin: 9.5 g/dl, leukocyte count: 10,012 cells/mm3, erythrocyte sedimentation rate (ESR) 45 mm/h, platelets: 416,000/mm3, serum glutamic pyruvic transaminase 22 IU/l, and serum creatinine 0.8 mg/dl. The …