ACUTE PHASE REACTANTS AND THEIR CORRELATION WITH CLINICAL ACTIVITY IN BEHCET'S DISEASE

Background: Behçet's disease (BD) is a multisystemic inflammatory disease mainly characterized by recurrent oral aphthae, genital ulcers, ocular and skin lesions. Although genetic factors, infectious agents and immunological mechanisms have all been implicated, pathogenesis of BD still remains to be elucidated. Correlation of clinical findings with acute phase response is usually considered poor, and there is no established biomarker for monitoring disease activity in BD patients. Objectives: This study aimed to analyze the correlation of serum levels of different acute phase reactants with the clinical activity of BD, by measuring ESR, CRP, SAA, IL-8, S100A12, and also S100A13, which plays a key role in the non-classical release of IL-1α. Methods: A group of 95 patients with BD (58 male, 37 female), 18 patients with familial Mediterranean fever (FMF), 22 healthy subjects were enrolled to the study. Among BD patients, 31 had an active disease with overt manifestations during the first sampling, and a second serum sample was collected from 24 after their clinical activity was controlled. A group of 32 BD patients had no manifestations for at least 6 months, and named as patients in remission, and 8 had only recurrent oral aphthous ulcers. All FMF samples were collected during an acute attack. Serum levels of CRP and SAA were measured by nephelometry and of S100A13, S100A12 (Cusabio Biotech, China) and IL-8 (BD Bioscienses, USA) by ELISA. The study protocol was approved by the local ethics committee, and all participants gave written informed consent. Results: The mean values ESR, CRP, SAA and IL-8 were significantly higher in active BD patients with manifestations compared to the values of patients with no manifestations (n=46, including inactive and remission patients) (43.7 vs 14.6, 36.2 vs 1.8, 133 vs 6.9, 28.5 vs 29.4, respectively) and to the values of the healthy controls (16.5, 1.65, 4.4 and 16.3, respectively). Analysis of paired samples of 24 patients during active and inactive periods also showed significant decrease of ESR, CRP, SAA, and IL-8 with the controlled activity (38 vs 14.2, 26.6 vs 2.1, 44.5 vs 6.8, 58.5 vs 7.8, respectively, P<0.001). Addition of patients with only oral ulcers to the active patients did not change the significant results, except IL-8. Patients with additional manifestations had significantly higher CRP values than patients with only oral ulcers. High (greater than mean + 2SD of healthy controls) S100A12 values were observed in 34% of active patients, and this proportion reduced to 5% with the decreased disease activity. Serum S100A13 values were below the detection level in all groups. In FMF patients, all acute phase reactants but IL-8 were higher than active patients with BD. Conclusions: This study reveals dynamic changes of acute phase reactants in parallel with disease activity in BD patients. The level of those elevations may reflect the total area of inflammatory lesions. Considering the magnitude of changes along with manifestations, serum CRP and SAA levels can be used for the monitoring of clinical manifestations and treatment responses of patients with BD. Acknowledgements: Supported by: Istanbul University, Scientific Research Projects Coordination Unit, IUBAP No: 2012/23482. Disclosure of Interest: None declared DOI: 10.1136/annrheumdis-2014-eular.5998Citation: Annals of the Rheumatic Diseases, volume 73, supplement 2, year 2014, page 547Session: Vasculitis (Poster Presentations )