We report two cases of tuberculosis (TB) after treatment with infliximab (IFX) for rheumatoid arthritis (RA). The first case, a 69-year-old woman with RA, developed miliary TB with acute respiratory distress syndrome 21 months after initiation of IFX therapy. Sputum samples revealed smears and cultures positive for Mycobacterium tuberculosis and also positive polymerase chain reaction for TB (PCR-TB); in addition urine samples were smear-negative and culture-positive for TB. She was treated with corticosteroid pulse therapy and anti-tuberculosis drugs, and recovered. The second case, a 51-year-old man with RA, had had contact with a tuberculosis patient four years after initiation of IFX therapy. One year later, he developed pulmonary and pleural tuberculosis. Mycobacterium tuberculosis was detected in the bronchial lavage fluid and pleural effusion (smear-negative and culture- and PCR-TB positive). He clinically improved by treatment with anti-tuberculosis drugs. In both cases, the enzyme-linked immunosorbent spot (ELISPOT) tests revealed positive responses although the QuantiFERON TB-2G tests were not positive. We suggest that the ELISPOT test may be useful as a supportive diagnostic tool for tuberculosis in immunocompromised conditions including RA treated with a tumor necrosis factor-alpha (TNF-alpha) inhibitor.
