LTBI screening in rheumatoid arthritis patients prior to anti-TNF treatment in an endemic area.

Setting: Recommendations for screening for latent tuberculous infection (LTBI) in patients eligible for anti-tumour necrosis factor (TNF) agents remain unclear in endemic regions.

Objective: To evaluate the long-term efficacy of LTBI screening and treatment in patients with rheumatoid arthritis (RA) receiving TNF blockers.

Design: A total of 202 RA patients were screened for LTBI before receiving anti-TNF treatment using the tuberculin skin test (TST), chest X-ray (CXR) and history of exposure to tuberculosis (TB). All subjects were regularly followed at 1- to 3-month intervals.

Results: Eighty-five patients (42%) were treated with a single anti-TNF agent, while 117 patients (58%) changed anti-TNF agents once or twice. LTBI screening was positive in 66 patients, 44 were TST-positive, 23 had a history of TB exposure and 14 had an abnormal CXR. Exposure alone accounted for LTBI diagnosis in 14 patients with a negative TST. LTBI patients were treated with isoniazid (300 mg/day) for 6 months, and none developed TB. During follow-up, TST was repeated in 51 patients. Conversion was observed in 5; 3 were diagnosed with LTBI and 2 with active TB respectively 14 and 36 months after receiving anti-TNF treatment, suggesting new TB exposure.

Conclusion: LTBI screening and treatment before anti-TNF treatment is effective in endemic areas and reinforces the importance of establishing contact history for diagnosing LTBI in RA patients.