INTRODUCTION: The diagnosis of latent tuberculosis (LTB) in patients with rheumatoid arthritis (RA) has become important with the introduction of anti-tumor necrosis factor (anti-TNF-α) agents and the appearance of active tuberculosis cases in these patients. The tuberculin skin test (TST) has limited value in patients with RA. Tests based on the release of interferon-gamma (IFN-γ) are being studied, but their role has not been well established for this group of patients. OBJECTIVES: To compare the diagnosis of LTB in patients with RA by using cellular immune response to the TST and T.SPOT-TB. Additionally, findings of tomography studies compatible with LTB were used. METHODS: Clinical evaluation, TST, T.SPOT-TB and high-resolution computed tomography (HRCT) in a group of patients with RA at the University Hospital of the Federal University of Goiás. RESULTS: Response to the TST was lower in patients with RA (13.5%) compared to the predicted values of the general population. T.SPOT-TB identified a higher number of patients with LTB than the TST (36.8%). HRCT showed changes compatible with LTB in 52.9% of the patients, including 8 of the 11 patients with negative TST and T.SPOT-TB. CONCLUSIONS: The TST by itself is insufficient to diagnose LTB. A higher number of positive results were obtained with T.SPOT-TB when compared to the TST. Nevertheless, it was negative in a large percentage of patients with tomography findings consistent with LTB. HRCT is readily available in most large health-care centers and it could be incorporated into the diagnostic strategy for LTB in patients with RA.
INTRODUCTION: The diagnosis of latent tuberculosis (LTB) in patients with rheumatoid arthritis (RA) has become important with the introduction of anti-tumornecrosis factor (anti-TNF-α) agents and the appearance of active tuberculosis cases in these patients. The tuberculin skin test (TST) has limited value in patients with RA. Tests based on the release of interferon-gamma (IFN-γ) are being studied, but their role has not been well established for this group of patients. OBJECTIVES: To compare the diagnosis of LTB in patients with RA by using cellular immune response to the TST and T.SPOT-TB. Additionally, findings of tomography studies compatible with LTB were used. METHODS: Clinical evaluation, TST, T.SPOT-TB and high-resolution computed tomography (HRCT) in a group of patients with RA at the University Hospital of the Federal University of Goiás. RESULTS: Response to the TST was lower in patients with RA (13.5%) compared to the predicted values of the general population. T.SPOT-TB identified a higher number of patients with LTB than the TST (36.8%). HRCT showed changes compatible with LTB in 52.9% of the patients, including 8 of the 11 patients with negative TST and T.SPOT-TB. CONCLUSIONS: The TST by itself is insufficient to diagnose LTB. A higher number of positive results were obtained with T.SPOT-TB when compared to the TST. Nevertheless, it was negative in a large percentage of patients with tomography findings consistent with LTB. HRCT is readily available in most large health-care centers and it could be incorporated into the diagnostic strategy for LTB in patients with RA.