Screening for latent tuberculosis infection among patients with rheumatoid arthritis in the era of biologics and targeted synthetic disease-modifying anti-rheumatic drugs in India, a high-burden TB country: The importance of Mantoux and Quantiferon-TB Gold tests.

Aim: To test the validity of an augmented tuberculosis skin test (a-TST) combined with Quantiferon TB-gold (QFTG) test for the screening of latent tuberculosis infection (LTBI) in patients with rheumatoid arthritis (RA) being considered for treatment with biologic disease-modifying anti-rheumatic drugs or targeted synthetic disease-modifying anti-rheumatic drugs.

Method: Standard TST using 1 tuberculin unit (TU) of purified protein derivative (PPD, RT23 strain) was carried out. If the positivity was less as compared to the general population, then a-TST using 10 TU PPD was employed.