Abstract
Background: Tumor necrosis factor alpha (TNFα) is a cytokine which acts as a central mediator of inflammation and immune regulation. Anti-TNFα therapy used in patients with chronic immune-mediated inflammatory diseases is associated with increased risk of tuberculosis activation (TB), especially in contries with high incidence of TB.
Objectives: evaluation oflatenttuberculosisinfection (LTBI)prevalenceand riskof developingactiveTBamong patientseligiblefor starting anti-TNFα therapy.
Methods: 257 of consecutive patients (71 with ankylosingspondylitis, 114 with psoriatic arthritis and 72 with rheumatoid arthritis) were enrolled. Demographic, clinical, radiological data andtherapeutic indications, prior to biologic treatment, were recorded. Tuberculinskintest(TST) and/orinterferon-γ releaseassay (IGRA) were performed for all patients. The occurrence of subsequent active TB was followed for 5 years.
Results: 146 had positive TST and 65 positive IGRA test. 211 patients (120 males, 91 females) were diagnosed with LTBI, all receiving preventative chemotherapy prior to biologics, consisting of 9 months of isoniazid. Only 46 patients (21 males, 25 females) were not TB infected (18%). No active TB cases occurred beyond the first year of treatment. 2 patients developed active pulmonary TB, with a mean duration of biologic treatment of 24 months.
Conclusions: The prevalence of LTBI among patients eligible for anti-TNF therapy was very high (82%), but the occurrence of active TB remained low (0.88%). We may consider either the protection offered by chemotherapy, either some natural population resistance to the disease.
- Copyright ©ERS 2015