Clinical Analysis of Safety in Latent Tuberculosis Infection Prophylaxis Treatment

Inclusion Criteria: * close contact with active TB patients * patients with autoimmune diseases preceding biological therapy * health-care workers * other clinical conditions, which increased the risk of LTBI. LTBI was confirmed by QuantiFERON-TB Gold In-Tube test (QFT-GIT; Qiagen, Valencia, CA, USA) with a cut-off value of 0.35 IU/ml. Exclusion Criteria: * age less than 20 years * pregnant women * active TB or suspected active TB in the clinical evaluation * severe liver disease * ESRD * organ transplantation * close contact with a multidrug-resistant TB patient * obesity (BMI\>30 Kgw/m2) and other conditions inappropriate for participation in this study as judged by the investigators.