FRI0033 QUANTIFERON GOLD-PLUS AND TUBERCULIN SKIN TEST REACTIVITY PREDICTORS IN PATIENTS WITH RHEUMATOID ARTHRITIS

Abstract

Background: RA patients have high latent tuberculosis(LTBI)prevalence(20-37%)1. In Mexico,ranges from 21.7% to 31.3% using tuberculin skin test (TST)2. The methods to detect LTBI are TST and IGRAs. QuantiFERON Gold-Plus (QTF-Plus)uses an antigen tube (TB1) that stimulates CD4+T cells and an additional tube (TB2) that also stimulates CD8+T cells3. Objectives: Determine the LTBI prevalence,variables that predict QTF-Plus and TST results and the concordance between TST and QTF-Plus in RA patients. Methods: A cross-sectional study in RA patients from the rheumatology department of the University Hospital “Jose E. Gonzalez” in Mexico between October 2017 and June 2018. RA patients with ACR/EULAR 2010 classification criteria without a history of tuberculosis (TB) were included.QFT-Plus was performed according to manufacturer instructions.TST was applied with the Mantoux technique; a ≥5mm cutoff was used.The square chi and Fisher test were used for proportions, Mann-Whitney to compare means,trend analysis using linear trend test and a binary logistic regression model for variables related to positivity to both tests. Results: We included 111 patients (table 1), the mean age was 51.9 years, 92.3% were women,disease duration 8.7±8.8 years. QTF-Plus was positive in 46 (44.6%) patients. TST was positive in 31(27.9%) patients.Agreement between tests was 73.7% (kappa=0.45, p Conclusion: The LTBI prevalence in RA patients in our study is similar to countries with a high TB burden.We recommend considering RA patients as a high-risk population for LTBI.An intermediate agreement between TST and QTF-Plus was found.The use of antimalarials and ≥2DMARDs influence the TST reactivity,none of the variables altered the QTF-Plus results.Based on the results, we recommend the QuantiFERON Gold Plus over TST for the LTBI screening in RA patients.