J Gastrointestin Liver Dis, March 2013 Vol. 22 No 1: 21-25 Department of Gastroenterology CIC, Catholic University, Rome, Italy Address for correspondence: Dr. Luisa Guidi Internal Medicine and Gastroenterology Unit Complesso Integrato Columbus, Università Cattolica del Sacro Cuore Via Moscati 31-33, 00168 Rome, Italy lguidi@rm.unicatt.it Received: 13.12.2012 Accepted: 18.01.2013 Comparison of Quantiferon-TB Gold versus Tuberculin Skin Test for Tuberculosis Screening in Inflammatory Bowel Disease Patients Gianluca Andrisani, Alessandro Armuzzi, Alfredo Papa, Manuela Marzo, Carla Felice, Daniela Pugliese, Italo De Vitis, Gian Lodovico Rapaccini, Luisa Guidi INTRODUCTION The reactivation of tuberculosis (TB) is a serious infectious complication in patients affected by inflammatory bowel disease (IBD) undergoing treatment with anti-tumor necrosis factor-alpha (TNF- α) agents. Noteworthy in the literature are documented cases of latent TB (LTB) reactivation and disseminated infections aſter the initiation of TNF-α therapy ABSTRACT Background & Aim: Screening for latent tuberculosis (LTB) is recommended before starting anti-TNF-α therapy. We compared the performance of Quantiferon-TB Gold (QFT-G) with the tuberculin skin test (TST) for the screening of LTB in a population of inflammatory bowel disease (IBD) patients who were candidates for anti-TNF-α therapy. Methods: Ninety-two IBD patients who were candidates for anti-TNF-α therapy were tested with QTF-G and TST. Concomitant therapy and laboratory parameters were recorded. Results: One subject was vaccinated with Bacille Calmette Guèrin (BCG), 76% of patients were on immunosuppressive therapy (IST), and all patients had a negative TB history and negative chest X-ray. Agreement between the two tests was observed in 89.2% of patients (79.4% +/+, 9.8% -/-), QFT-G+/TST- was observed in 4.4% (4) patients, and QFT-G-/TST+ was observed in 5.5%, one of which was previously vaccinated. All disagreements were observed in patients on IST (14.3% in this group). e agreement analysis showed moderate strength among the patients (k=0.508), while the agreement was only fair in the subgroup of patients on IST (k=0.388). Conclusion: Given the high risk of LTB reactivation in patients subjected to anti-TNF-α therapy, our results suggest that in our population, with low TB rate and very low BCG vaccination rate, both tests could be employed. Key words: inflammatory bowel disease – latent tuberculosis – Quantiferon test – tuberculin skin test – anti- TNF-α. Abbrevations: INHA: isoniazide; AZA: azathioprine; BCG: Bacille Calmette Guèrin; CFP-10: culture filtrate protein-10; ESAT-6: early secretory antigen target-6; IBD: inflammatory bowel disease; IFN: interferon; IGRA: interferon-gamma release assay; IST: immunosuppressive therapy; LTB: latent tuberculosis; QFT-G: Quantiferon-TB gold; TB: tuberculosis; TNF-α: tumor necrosis factor-alpha; TST: tuberculin skin test. [1]. Animal models have shown the importance of TNF-α in controlling intracellular pathogens[2]. erefore, latent TB (LTB) screening is strongly recommended before starting any anti-TNF-α therapy [3]. In Italy, incidence rates of TB have been fairly stable in the last two decades around 7 reported cases per 100,000 population [4] and the Bacille Calmette Guérin (BCG) vaccination rate is very low. Traditionally, screening includes a thorough medical history, chest x-rays, and a tuberculin skin test (TST); however, the use of TST is controversial due to its high rate of false- negative results as a consequence of previous long-term immunosuppressive treatments (IST) [5]. e specificity of the TST is low because of the false positive results in patients who have been vaccinated with BCG and in those infected by