AB0576 SERUM CATHELICIDIN (LL 37) LEVELS IN PATIENTS WITH BEHCET’S DISEASE AND ITS ASSOCIATION WITH DISEASE ACTIVITY

Background: Behcet’s disease (BD) is a recurrent multisystem inflammatory disease which is characterized by recurrent episodes of oral aphthous and genital ulcers, ocular inflammation and skin lesions. Anti-microbial peptides (AMPs) such as the cathelicidin (LL-37) and defensins have recently been implicated in the pathogenesis of autoimmune and autoinflammatory diseases. Objectives: The aim of this study was to investigate the serum levels of cathelicidin and its potential association with disease activity, and some other laboratory parameters such as erythrocyte sedimentation rate (ESR) and C-reactive protein (CRP), white blood cell count (WBC) in patients with BD. Methods: A total of 45 patients who presented to Dicle University Rheumatology clinics between September 2018 and December 2018 and met the International Study Group Classification Criteria for BD and 37 healthy control subjects who presented to Dicle University Physical Medicine and Rehabilitation clinics for various reasons other than rheumatoid complaints between the same dates were included in this study. Patients’ demographic features, including age and sex, were noted. Duration of disease was also noted, and the disease activity was assessed by means of BD Current Activity Form (BDCAF). Laboratory investigations included erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), complete blood count and routine biochemical analyses. Serum levels of cathelicidin (LL 37) were determined by means of human cathelicidin antimicrobial peptide ELISA Kit according to the manufacturer’s protocol. Results: Serum mean level of cathelicidin (LL 37) in patients with BD was lower than healthy controls but this result was not statistically significant. Cathelicidin levels were not correlated with ESR, CRP, BDCAF and WBC (p>0.05). Conclusion: However serum mean levels of cathelicidin (LL 37) were lower in patients with BD compared to healthy controls, this result was not statistically significant. It may may be sourced from our relatively small sample size. To validate cathelicidin (LL 37) value as a prognostic or pathophysiologic biomarker, future studies should investigate the levels of cathelicidin LL37 in patients with BD in large cohorts of patients with different levels of disease activity, remission, and relapse. Reference [1] Hoffmann MH, Bruns H, Backdahl L, et al. The cathelicidins LL-37 and rCRAMP are associated with pathogenic events of arthritis in humans and rats. Ann Rheum Dis. 2013;72(7):1239-48 [2] Gasim A. Cathelicidin antimicrobial peptide as a serologic marker and potential pathogenic factor in antineutrophil cytoplasmic antibody-associated vasculitis. Arthritis Res Ther. 2014: 28;16(1):105 Disclosure of Interests: None declared