Comparação entre o interferon-gamma release assay e o teste cutâneo tuberculínico para rastreio de tuberculose latente antes e durante a terapia anti-TNFɑ em pacientes com doença inflamatória intestinal no Rio de Janeiro, Brasil

• Autor(a) principal: Amorim, Renata Fernandes de
• Data de Publicação: 2019
• Tipo de documento: Dissertação
• Idioma: por
• Título da fonte: Biblioteca Digital de Teses e Dissertações da UERJ
• Texto Completo: http://www.bdtd.uerj.br/handle/1/8638
• topic: Inflammatory bowel disease; Latent tuberculosis; Tuberculin skin test; Interferon gamma release assay; Doença inflamatória intestinal; Tuberculose latente; Derivado proteico purificado; Ensaio de produção interferon gamma; Intestinos Doenças inflamatórias; Tuberculose Latente; Interferon gama; Testes cutâneos; CNPQ::CIENCIAS DA SAUDE::MEDICINA::CLINICA MEDICA::GASTROENTEROLOGIA

Some patients with inflammatory bowel disease (IBD) are treated with anti-TNFɑ for a better control and maintenance of the disease. Anti-TNFɑ therapy increases the risk of reactivation of tuberculosis and therefore all IBD patients require screening for latent tuberculosis (LTBI) before therapy. In Brazil, the screening methods for LTBI are chest X-ray and tuberculin skin test (TST). However, TST could have false negative results, mainly in patients with immunosuppression therapy, who have a high chance of developing tuberculosis. Another available method, interferon gamma release assay (IGRA), measures ex vivo the peripheral blood gamma interferon of patients when they are exposed to tuberculosis mycobacterium-specific antigens. The objective of this study was: (i) to evaluate the agreement between PT and IGRA in the screening of LTBI in naïve patients; (ii) to evaluate the need to repeat screening tests after the beginning of anti-TNF therapy; (iii) to evaluate whether screening tests are influenced by immunosuppression. TST was performed by a certified nurse and IGRA was performed in the pathology sector of the Faculty of Medical Sciences (FMS) of the University of the State of Rio de Janeiro-UERJ. As a result, 89 patients with Crohn's disease (CD), 21 patients with idiopathic ulcerative colitis (UC) and 64 controls participated in the study. The agreement between TST and IGRA was poor regarding diagnosis (kappa: control=0.318; UC=0.202; and CD=-0.093), anti-TNFɑ therapy (kappa: w/o anti-TNFɑ: -0.123; with anti-TNFɑ: 0.150), and the use of immunosuppressant (IS) (kappa: w/o IS: 0.146; with IS: -0.088). Considering IGRA as criterion Standard, TST showed a very low overall sensitivity of 19.05% and a PPV of 21.05%. However, a remarkable relative increase in the detection of LTBI occurred when IGRA was added to TST (sensitivity of 80.95% and a PPV of 53.13%). Although TST does not appear to be significantly affected by the use of immunosuppressant or other clinical variables, patients with CD showed the lowest sensitivity and a PPV of 0.0% and 0.0%. Among these patients, when IGRA was analyzed as an add-on sequential test to TST, results remarkably improved (sensitivity of 66.67% and a PPV of 61.54%). IGRA alone was more effective to detect LTBI than TST alone which had an added value of ~60% as an add-on sequential test, particularly important in CD patients. Although the cost-effectiveness of these strategies remains to be evaluated, IGRA appears to be justified in CD prior to and during anti-TNFɑ therapy, in endemic areas for Mtb where BCG is universally applied to the population.