Efficacy of isoniazid salvage therapy for latent tuberculosis infection in patients with immune-mediated inflammatory disorders – A retrospective cohort study in Taiwan

Abstract

Background: Active tuberculosis (TB) in patients with latent tuberculosis infection (LTBI) was associated with use of biological agents for immune-mediated inflammatory disorders (IMIDs). For decreasing active TB, isoniazid prophylaxis therapy was administered before biologic therapy among IMID patients with LTBI. However, for patients who had been received biologics for a long time with unknown status of LTBI or exposure history of active TB, the prevalence of LTBI and efficacy of isoniazid therapy were unclear. Method: A retrospective cohort study was conducted during 2012–2014 in a tertiary medical center in Taiwan, and the incidence case of active TB was identified by the national TB registration system on October 1, 2015. Results: All 382 patients with 1532 person-years were followed up, the initial prevalence of LTBI by positive interferon-gamma releasing assay (IGRA+) was 17.5%. The prevalence of LTBI was increased in elder age (>20%, p 0.05). Conclusion: Isoniazid therapy can prevent active TB from LTBI despite of the timing of biologics administration. Keywords: DMARD, Isoniazid, Tuberculosis