The introduction of biological agents, especially the tumor necrosis factor inhibitors (anti-TNF), for the treatment of rheumatic diseases increased the risk of developing tuberculosis (TB). Screening for latent TB infection (LTBI) is strongly recommended before starting therapy with anti-TNF agents. The objective of this study was to identify the prevalence of LTBI and TB among patients with rheumatic diseases on anti-TNF agents. This is a cross-sectional study. The electronic medical records of all adult patients (≥18 years old) undergoing anti-TNF treatment were reviewed. Every patient underwent tuberculin skin test (TST) before starting anti-TNF treatment. In total, 176 patients were included; the mean age was 51.9 ± 12.4 years, 34.7% were males, and 90.9% were white. The underlying diseases were rheumatoid arthritis (RA) in 50.6% (N = 89), ankylosing spondylitis (AS) in 27.8% (N = 49), and psoriatic arthritis (PsA) in 17.6% (N = 31). The prevalence of positive TST was 29.5%. Household contact with TB was significantly associated with a positive TST (p = 0.020). RA patients had lower TST reactions than AS patients (p = 0.022). There were six cases of TB (3.4%) diagnosed during anti-TNF therapy. We demonstrated a high prevalence of positive TST (29.5%) among patients with rheumatic diseases in a region with high TB prevalence. Our data corroborates the ACR's recommendation that patients who live in high TB incidence settings should be tested annually for LTBI.

BackgroundThe introduction of biological agents, especially the tumor necrosis factor inhibitors (anti-TNF) for the treatment of rheumatic diseases increased the risk of developing tuberculosis (TB). Screening for latent TB infection (LTBI) is strongly recommended before starting therapy with anti-TNF agents.ObjectivesThis study aimed to identify the prevalence of LTBI and TB among patients with rheumatic diseases on anti-TNF drugs.MethodsIn a cross-sectional study, the electronic medical records of all adult patients (≥18 years old) undergoing anti-TNF treatment at Hospital de Clínicas de Porto Alegre, Porto Alegre, Brazil, were reviewed. Every patient underwent Tuberculin Skin Test (TST) before starting anti-TNF treatment.ResultsIn total, 176 patients were included. The mean age was 51.9±12.4 years, 34.7% were males, and 90.9% were white. The underlying diseases were rheumatoid arthritis (RA) in 50.6% (N=89), ankylosing spondylitis (AS) in 27.8% (N=49) and psoriatic arthritis (PsA) in 17.6% (N=31). Anti-TNF agents started after TST were: infliximab (22.7%, N=40), adalimumab (48.9%, N=86), etanercept (27.3%, N=48), and golimumab (1.1%, N=2). The prevalence of positive TST was 29.5%. Household contact with TB was significantly associated with a positive TST (p=0.020). RA patients had lower TST reactions than AS patients (p=0.022). There were six cases of TB (3.4%) diagnosed during anti-TNF therapy.ConclusionsWe demonstrated a high prevalence of positive TST (29.5%) among patients with rheumatic diseases in a region with high TB prevalence. Our data corroborates the ACR's recommendation that patients who live in high TB incidence settings should be tested annually for LTBI.References Ishiguro T, Takayanagi N, Kagiyama N, Yanagisawa T, Sugita Y: Characteristics of tuberculosis in patients with rheumatoid arthritis: a retrospective single-center study. Intern Med 2014, 53: 1291–1298.Arkema EV, Jonsson J, Baecklund E, Bruchfeld J, Feltelius N, Askling J: Are patients with rheumatoid arthritis still at an increased risk of tuberculosis and what is the role of biological treatments? Ann Rheum Dis 2015, 74: 1212–1217.Singh JA, Furst DE, Bharat A, Curtis JR, Kavanaugh AF, Kremer JM et al.: 2012 update of the 2008 American College of Rheumatology recommendations for the use of disease-modifying antirheumatic drugs and biologic agents in the treatment of rheumatoid arthritis. Arthritis Care Res (Hoboken ) 2012, 64: 625–639. Disclosure of InterestNone declared