Background Tuberculosis is a major infectious problem during anti-TNF treatments in tuberculosis prevalent countries. BCG vaccine may influence tuberculosis skin test (TST) results in these countries. Quantiferon-TB test may replace TST test for screening of tuberculosis.

Objectives To assess quantiferon-TB and TST tests positivity for assessment of prophylactic anti-tuberculosis treatment.

Methods Hacettepe University Biological Database (HUBİD) include approximately 1800 patients since 2005. TST test was used between 2005 to 2011 for the assessment of latent tuberculosis. After 2011 in HUBİD, quatiferon-TB test was used for this purpose in routine clinical practice. We searched database for TST (positive (>5mm) and negative), quantiferon-TB (positive and negative), and starting anti-tuberculosis prophylaxis.

Results TST results were known in 846 patients. Seven hundred six (83.4%) of patients had positive TST results, and anti-tuberculosis prophylaxis were started in those patients. Quantiferon-TB results were known in 387 patients, since 2011. Eighty five of 387 (21.9%) patients had positive quantiferon-TB test. Forty six patients had both TST and quatiferon-TB test results. Ten of 46 patients (21.7%) had positive TST and positive quantiferon-TB test. Those patients were taken anti-tuberculosis prophylaxis. Twenty five of 46 (54.3%) patients had positive TST and negative quatiferon-TB test. Nine of 46 (19.6%) patients had both negative TST and quatiferon-TB.

Conclusions Isoniazid prophylaxis has important advers effect such as liver dysfunction and neuropathy. Almost 80% of patients were received INAH prophylaxis when TST test used for screening. However, only almost 20 % of patients were received INAH prophylaxis when quantiferon-TB test were used. Concordance of both test is very low particularly countries under routine BCG vaccine. Closer follow-up of patients who were not put on isoniazid prophylaxis according to quantiferon-TB results are mandatory and the results of this follw-up may change approach to tuberculosis prophylaxis.

Disclosure of Interest None Declared