AB1282-HPR CONCORDANCE BETWEEN TUBERCULIN TEST AND INTERFERON-GAMMA RELEASE ASSAY IN THE SCREENING OF LATENT TUBERCULOSIS INFECTION IN PATIENTS WHO ARE GOING TO INITIATE A TNF INHIBITOR

Background:The drugs that inhibit tumor necrosis factor (anti-TNF) alpha can reactivate a latent tuberculosis infection (ILTB) so requiring a rigorous screening before its onset. The tuberculin test (PT) has a high false negative rate in patients with immunomediated rheumatic diseases (IMID) and false positive in patients vaccinated with Bacillus Calmette Guérin (BCG). The neu methods of interferon gamma release (IGRA) seem to solve this problem, but its use is not standardized.Objectives:Establish the degree of concordance in the diagnosis of ILTB between PT and IGRA in patients who are going to star an anti-TNF drug, in general, and in different situation like taking corticosteroids, being treated with disease modifying drugs, have been vaccinated with BCG or have risk factor for ILTB.Methods:From May 2016 to November 2019, 195 patients with IMID who underwent ITLB screening prior to the initiation of an anti-TNF drug were included in this study. The concordance between PT and IGRA was calculated using the cohen’s kappa index, for the general sample first and then for subgroups. An analysis of the factor that influence the result of PT and IGRA has also been carried out.Results:The prevalence of ILTB was 26.7%. Of the total positive PT and Booster (n=50), QTF-G-IT was positive only in 15 patients (30%). The agreement between PT and QTF-G-IT was 0.33 (p<0.05). In the subproups, a moderate agreement was found in patients who did not take corticosteroids (k=0.45, p<0,05) and greater than the global one in those who had risk factor for ITLB (k=0.37, p<0.05).Conclusion:In our study the agreement between PT and QT-G-IT is low in general, being somewhat higher in unvaccinated patients and with a high probability for ILTB. Taking this result into account due to the low concordance, the ideal ILTB screening strategy in patients who are going to start a anti-TNF would consist of performing both tests.References:[1]Goletti D, Petrone L, Ippolito G, Niccoli L, Cantini F, Goletti D, et al. Expert Review of Anti-infective Therapy Preventive therapy for tuberculosis in rheumatological patients undergoing therapy with biological drugs with biological drugs. Expert Rev Anti Infect Ther. 2018;16(6):501-12.[2]Ortiz AM, González-álvaro I, Laffón A. Mecanism os de acción de fármacos modificadores de la evolución de la artritis reumatoide. 2001;420-7.[3]Algood HMS, Lin PL, Flynn JL. Tumor necrosis factor and chemokine interactions in the formation and maintenance of granulomas in tuberculosis. Clin Infect Dis. agosto de 2005;41 Suppl 3:S189-93.[4]Bopst M, Garcia I, Guler R, Olleros ML, Rulicke T, Muller M, et al. Differential effects of TNF and LTalpha in the host defense against M. bovis BCG. Eur J Immunol. junio de 2001;31(6):1935-43.[5]Winthrop KL, Novosad SA, Baddley JW, Calabrese L, Chiller T, Polgreen P, et al. Opportunistic infections and biologic therapies in immune-mediated inflammatory diseases: consensus recommendations for infection reporting during clinical trials and postmarketing surveillance. Ann Rheum Dis. diciembre de 2015;74(12):2107-16.[6]Randhawa PS. Lymphocyte subsets in granulomas of human tuberculosis: an in situ immunofluorescence study using monoclonal antibodies. Pathology. julio de 1990;22(3):153-5.[7]Gardam MA, Keystone EC, Menzies R, Manners S, Skamene E, Long R, et al. Anti-tumour necrosis factor agents and tuberculosis risk: mechanisms of action and clinical management. Lancet Infect Dis. marzo de 2003;3(3):148-55.[8]Keane J, Gershon S, Wise RP, Mirabile-Levens E, Kasznica J, Schwieterman WD, et al. Tuberculosis associated with infliximab, a tumor necrosis factor alpha-neutralizing agent. N Engl J Med. octubre de 2001;345(15):1098-104.[9]Gomez-Reino JJ, Carmona L, Valverde VR, Mola EM, Montero MD. Treatment of rheumatoid arthritis with tumor necrosis factor inhibitors may predispose to significant increase in tuberculosis risk: a multicenter active-surveillance report. Arthritis Rheum. agosto de 2003;48(8):2122-7.Disclosure of Interests:None declared