Bacteriologically Determined De Novo Tuberculosis during Tumor Necrosis Factor-α Inhibitor Therapy

A 58-year-old man with Crohn's disease received adalimumab for 13 months after screening results for tuberculosis were found to be negative. He was diagnosed with de novo mediastinal lymph-node tuberculosis, which was proved to be bacteriologically identical to that of an individual with smear positive lung tuberculosis by a variable number of tandem repeat analyses. After initiating anti-tuberculosis therapy, the patient developed immune reconstitution syndrome, which was improved by the re-administration of adalimumab. Even in countries with an intermediate tuberculosis burden, including Japan, we need to be alert for de novo tuberculosis as well as its reactivation during tumor necrosis factor-α inhibitor therapy.