Objective: To evaluate the performance of interferon gamma release assays and tuberculin skin test in HIV-infected children and adolescents with immune reconstitution. Methods: A cross-sectional study was conducted in HIV-infected patients aged 5-18 years receiving antiretroviral treatment with CD4 T-lymphocytes >25% or >500 cells/mm3 for at least 6 months. QuantiFERON-TB Gold, T-SPOT.TB, and tuberculin skin test were performed in each patient. Results: A total of 50 patients were enrolled with median age of 13.7 years, CD4 counts of 753 (IQR: 587-989) cells/mm3. Among 27 patients with tuberculosis (16) or tuberculosis exposure (11), 8 (29.6%) were positive to at least one test, 2 (7.4%) were positive QuantiFERON-TB Gold, 3 (11.1%) positive T-SPOT.TB, and 7 (25.9%) had tuberculin skin test ≥5 mm. Among 23 patients without history of tuberculosis or exposure, all had negative interferon gamma release assays, while 2 (8.7%) had positive tuberculin skin test. Conclusions: All tests had low sensitivity despite immune reconstitution. Lapphra Keswadee 1 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Diwitaya Rati 2 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Senawong Sansnee 3 Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Thovarabha Maneeprang 4 Department of Immunology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Pinnobphun Parnwas 5 Biomed Diagnostics (Thailand) Co LTD, Bangkok Maleesatharn Alan 6 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Kongstan Nantaka 7 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Khumcha Benjawan 8 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Phongsamart Wanatpreeya 9 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Wittawatmongkol Orasri 10 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Rungmaitree Supattra 11 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok Chokephaibulkit Kulkanya 12 Department of Pediatrics, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok CDC. TB elimination interferon-gamma release assay (IGRAs)-blood tests for TB infection. [Online]. Available from: http://www.cdc.gov/tb/publications/factsheets/testing/IGRA.pdf. [Accessed on 30 September 2017]. ATS/CDC. Targeted tuberculin testing and treatment of latent tuberculosis infection. MMWR Recomm Rep 2000; 49(RR06): 1-54. Tieu HV, Suntarattiwong P, Puthanakit T, Chotpitayasunondh T, Chokephaibulkit K, Sirivichayakul S, et al. Comparing interferon-gamma release assays to tuberculin skin test in Thai children with tuberculosis exposure. PLoS One 2014; 9(8): e105003. Viera AJ, Garrett JM. Understanding interobserver agreement: The kappa statistic. Fam Med 2005; 37(5): 360-363. Caldwell MB, Oxtoby MJ, Simonds RJ, Lindegren ML, Rogers M, Division of HIV/AIDS National Center for Infectious Diseases, et al. 1994 Revised classification system for human immunodeficiency virus infection in children less than 13 years of age. MMWR Recomm Rep 1994; 43(RR-12): 1-10. Taylor Z, Nolan CM, Blumberg HM. Controlling tuberculosis in the United States: Recommendations from the American Thoracic Society, CDC, and the Infectious Diseases Society of America. MMWR Recomm Rep 2005; 54(RR12): 1-81. World Health Organization. Guidelines for intensified tuberculosis case-finding and isoniazid preventive therapy for people living with HIV in resource-constrained settings. 2011. [Online]. Available from: http:// apps.who.int/iris/bitstream/10665/44472/1/9789241500708_eng.pdf. [Accessed on 30 August 2017]. Cruz AT, Marape M, Gravis EA, Starke JR. Performance of the QuantiFERON-TB gold interferon gamma release assay among HIV-infected children in Botswana. J Int Assoc Provid AIDS Care 2015; 14(1): 4-7. Knox KS, Day RB, Kohli LM, Hage CA, Twigg HL 3rd. Functional impairment of CD4 T cells despite normalization of T cell number in HIV. Cell Immunol 2006; 242(1): 46-51. Menzies D. Interpretation of repeated tuberculin tests. Boosting, conversion, and reversion. Am J Respir Crit Care Med 1999; 159(1): 15-21.