Impact of New Immunological Diagnosis Tests of Latent Tuberculosis Before Anti TNF Therapy

Overview

Tuberculosis is a current infection during anti TNF therapy. After infectious contact, some patients will develop tuberculosis and some will only be infected without symptoms, they have Latent Tuberculosis Infection (LTBI) wich can reactivate later. In order to prevent this tuberculosis reactivation, LTBI diagnosis screening is preconised in patients who need anti TNF therapy. This diagnosis is made till now by the tuberculin skin test (TST) but this test is not specific of TB. New blood tests (QFTB-G and T-SPOT.TB) specific to MTB infection are now available. The primary endpoint of this study is the evaluation of the theoric therapeutic impact of the use of new tests for diagnosis of LTBI in patients before anti TBF therapy

Detailed description : Principal outcome: Therapeutic impact of the use of new tests for diagnosis of LTBI in patients before anti TBF therapy Secondary outcomes : * medico-economic impact of replacement of TST by QFTB-G and T-SPOT.TB tests in LTBI screening in patients before anti TNF therapy. * concordance of QFTB-G and T-SPOT.TB tests results with TST * Concordance between QFTB-G and T-SPOT.TB tests and evaluation of indetermined tests. * concordance of QFTB-G and T-SPOT.TB tests results with patient disease. * concordance of QFTB-G and T-SPOT.TB tests results with TST in patients with LTBI determinated by clinical or radiological observation * Impact of geographical, disease and treatment in patients with LTBI determinated by clinical or radiological observation * Identify the original characteristic and maximal impact therapeutic of QFTB-G and T-SPOT.TB test Analysed criteria : * therapeutic impact * Patients percentage with different therapeutic outcome based on usual recommendations medico-economic * Medico-economic impact :impact of both tests as early and late cost - efficacy Statistic : * Primary criteria : Percentage of patients for whom therapeutic would have been changed by QFTB-G and T-SPOT.TB tests results compared to usual diagnosis strategy. * Secondary criteria : Concordance of QFTB-G and T-SPOT.TB tests with TST Concordance between both QFTB-G and T-SPOT.TB tests . 400 patients Timing : inclusions : 1 years