Recommendations for the diagnosis and treatment of latent and active tuberculosis in patients with inflammatory joint diseases treated with tumour necrosis factor alpha inhibitors

The Portuguese Society of Rheumatology (SPR) and the Portuguese Society of Pulmonology (SPP) have developed guidelines for the diagnosis and treatment of latent tuberculosis infection (LTBI) and active tuberculosis (AT) in patients with inflammatory joint diseases (IJD), namely rheumatoid arthritis, psoriatic arthritis and ankylosing spondylitis, treated with tumour necrosis factor alpha (TNF-alpha) antagonists. Due to the high risk of tuberculosis (TB) in patients with IJD, LTBI and AT screening should be performed as soon as possible, ideally at the moment of IJD diagnosis. Even if TB screening was performed at the beginning of the disease, the evaluation should be repeated before starting anti-TNF-alpha therapy. When TB (LTBI orAT) treatment is indicated, it should be performed before the beginning of anti-TNF-alpha therapy. If the IJD activity requires urgent anti-TNF-alpha therapy, these drugs can be started after two months of antituberculosis therapy in AT cases, or after one month in LTBI cases. Chest X-ray is mandatory for all patients. If abnormal, e.g. Gohn complex, the patient should be treated as LTBI; residual lesions require the exclusion of AT and patients with history of untreated or incomplete TB treatment should be treated as LTBI. In cases of suspected active lesions, AT diagnosis should be confirmed and adequate therapy initiated. Tuberculin skin test (TST), with two units of RT23, should be performed in all patients. If induration is less than 5 mm, the test should be repeated after 1 to 2 weeks, on the opposite forearm, and should be considered negative if the result is again inferior to 5 mm. Positive TST implicates LTBI treatment. IfTST is performed in immunosupressed IJD patients, LTBI treatment should be offered to the patient before starting anti-TNFalpha therapy, even in the presence of a negative test.