AB0256 INCREASED SERUM PROCALCITONIN CONCENTRATION IN PATIENTS WITH RHEUMATOID ARTHRITIS FREE OF ACTIVE INFECTION

Abstract

Background:Rheumatoid arthritis (RA) is the most common inflammatory arthritis, affecting 0.5-1% of the general population worldwide. Patients with RA are often in a relatively immunocompromised status. Previous study have evaluated procalcitonin (PCT) application among autoimmune and autoinflammatory diseases for the diagnosis of systemic bacterial infection (1, 2) To date, the correlation of baseline PCT levels and RA disease activities, different treatment, or the expression of proinflammatory cytokines in patients with RA remained unknown.Objectives:To investigate the baseline PCT levels among patients with RA without active infection compared with healthy controls and to understand the relationship of PCT with RA disease activity, treatment received by patients, and the expression of proinflammatory cytokines.Methods:Patients aged 20 years and above, with clinician-confirmed diagnosis of RA were included during regular outpatient visits. RA disease activity was measured using the DAS28-ESR.Results:A total of 623 patients with RA and 40 healthy subjects were recruited in this study. The mean PCT were significantly higher in patients with RA (6.90 ± 11.81 * 10-3ng/mL) compared with healthy controls (1.14 ± 3.26 * 10-3ng/mL) (p = 0.002). After adjusted for age and sex, the PCT levels remain significantly elevated in patients with RA (p = 0.001). PCT was not significantly correlated with biologic agent, age, sex, disease duration, disease activity, C-reactive protein, conventional synthetic disease-modifying antirheumatic drugs (csDMARD), and comorbidities. Multiple linear regression analysis showed that PCT was inversely associated with the expression of IL-1β (B = −0.883; CI 95% −1.388, −0.378, p = 0.001) and IFN-α (B = −1.197; CI 95% −2.153, −0.242, p = 0.014) after adjusted for age and sex.Conclusion:Patients with RA have significantly higher baseline PCT compared with healthy controls. The treatment received by patients with RA did not affect the level of PCT. Further investigation is required to determine the optimal cutoff value of PCT among patients with RA before applying it in daily clinical practice.References:[1]Scire CA, Cavagna L, Perotti C, Bruschi E, Caporali R, Montecucco C. Diagnostic value of procalcitonin measurement in febrile patients with systemic autoimmune diseases. Clin Exp Rheumatol. 2006;24(2):123−8.[2]Delevaux I, Andre M, Colombier M, Albuisson E, Meylheuc F, Begue RJ, et al. Can procalcitonin measurement help in differentiating between bacterial infection and other kinds of inflammatory processes? Ann Rheum Dis. 2003;62(4):337−40.Acknowledgments:The authors gratefully acknowledge Dr. Malcolm Koo for advice on statistical analysis and manuscript preparation.Disclosure of Interests:None declared