Avaliação do tratamento da tuberculose latente em pacientes com doenças inflamatórias crônicas imunomediadas submetidos à terapia imunobiológica : seguimento de 4 anos, em área endêmica

Abstract

Latent TB (LTB) is the presence of M. tuberculosis in the organism without clinical evidence of disease. Approximately 90-95% of infected individuals are capable of triggering an immune response that prevents the progression of LTB for TB disease. However, some clinical situations can act as risk factors for the onset of tuberculosis, including patients with chronic immune-mediated inflammatory diseases, in use of biological agents. OBJECTIVE: To evaluate the safety and effectiveness of treatment with isoniazid in latent tuberculosis in patients with chronic immune-mediated inflammatory disease receiving biological agents. METHODS: A prospective cohort study involving 101 patients with diseases chronic immune-mediated inflammatory and candidates to the use of biological agents with positive screening for latent TB and prophylactic treatment with isoniazid, selected at time zero and followed for a period of four years (2011- 2015). Before the use of biological agents, it was done a screening for TBL using the tuberculin skin test (TST), chest radiography (RX) and evaluation of clinical TB. RESULTS: This study we found the majority of the patients were females 54.46% (55/101). The average age of the patients was 49.62 ± 1.40, being considered the most prevalent age group 40-59 years, representing 51.49%. The rheumatic diseases were prevalent in 83.17% (84/101). And, 78.22% (79/101) were treated with biological agents. In the diagnosis of latent tuberculosis, exposure to disease TB was considered high, at 38.61% of screened patients and the chest radiography changed by images compatible with latent infection was observed in 35.64%. The cut point of the TT for considering the positive screening of TBL was set at ≥ 5 mm. Thus, the diameter of induration of the TT ranged from 5 to 40 mm with an average of 12.059 ± 0.595 and median of 11 mm. Most patients 52.48% presented a strong reaction to the TT, with measures greater than 10 mm. With respect to prophylactic treatment, was used isoniazid, in a period of 6 six months, with percentage of 90.09% (91/101) or, exceptionally, for 9 months, with a percentage of 9.90% (10/101). The adhesion was high regardless of the period of treatment, 94.50% (86/101) to 6 months and 100.0% for 9 months, so that conclusion was 95.05% (96/101). The discontinuation due to an adverse event occurred in only (4/101) 3.96%, it was observed the abandonment in 0.99% (1/101) of the patients. It is relevant to mention that in 83.17% (84/101) there was any type of adverse effect to INH, of these (83/84) 98.81% completed the prophylactic treatment. Thus, it appears from the results that the relationship between the non-appearance of adverse effects, and the prophylactic treatment in relation to completion was statistically significant, with p < 0,002. The associated temporary adverse effects with the prophylactic treatment were observed in only (17/101) 16.83%. However, 76.47% (13/17) were able to complete the prophylactic treatment, the remaining (4/101) 3.96% discontinued the prophylactic treatment, two because of the drug intolerance, and two due of the symptomatic liver toxicity. However, only 2.97% (3/101) experienced hepatotoxicity, and of these, two patients did not completed treatment, it was statistically significant, p < 0,001. CONCLUSION: The use of isoniazid, for a period of 6 months showed to be safe and effective. The safety profile presented by INH in relation the tolerance and the possible reduction of risk of disease TB, on the order of 60% to 90% by users of the biological agents, the prophylactic treatment in candidates for use of biological agents, require continuous surveillance, what should be maintained, because of the signs indicating the emergence of infectious processes, specifically, suspected cases of TB.