FRI0564 SERUM LEVELS OF IL-6 AND IL-8 IN ANKYLOSING SPONDYLITIS PATIENTS: ASSOCIATIONS WITH DISEASE ACTIVITY

Abstract

Background:Ankylosing spondylitis (AS) is a chronic inflammatory disease of the spine and sacroiliac joints characterized by new bone formation (syndesmophytes) and ankyloses. In AS cases, along with the damage to the musculoskeletal system, impairment of other organs and systems is often observed (uveitis, inflammatory bowel and heart diseases). Pro-inflammatory cytokines (TNF-α, IL-6,-17,-23,-21,-22,-31) and chemokines (IL-8) are key pathogenic markers in AS.Objectives:The aims of the study were to determine the serum levels of IL-6 and IL-8 in AS and investigate their relationship with disease activity.Methods:We studied 140 patients (pts) with AS fulfilled modified New York criteria (1984); (102M/38F); median and interquartile range (25th—75th percentile) of age 43.0; 35.0-51.0 years; disease duration 6.0; 4.0-12.0 years; BASDAI - 5.4; 4.1-6.6; ASDAS ESR - 3.6; 2.6-4.4; ASDAS CRP - 3.8; 2.7-4.5; 86% HLA-27 positive. In 50% of pts with AS, inflammatory bowel diseases (IBD) (Crohn’s disease and ulcerative colitis) were diagnosed. The control group included 17 healthy donors (HC). The serum concentrations of IL-6 and IL-8 were detected by chemiluminescence immunoassay using IMMULATE 1000 analyzer (Siemens Healthcare Diagnostics, USA).Results:AS pts had significantly higher serum level of IL-6 than HC (4.3; 0.1-8.0 pg/ml vs 2.3; 0.1-2.7 pg/ml, p <0.006). The median concentration of IL-8 didn’t differ between AS pts and HC (10.5; 8.3-18.0 pg/ml vs 11.9; 8.2-18.3 pg/ml, p>0.05). The same levels of IL-6 and IL-8 were detected in AS with IBD and AS without signs of IBD (p>0.05). In AS pts, serum IL-6 concentration was positively correlated with ASDAS ESR (r = 0.3), ASDAS CRP (r = 0.3), ESR (r = 0.3) and CRP (r = 0.5) (p <0.05); IL-8 was negatively associated with presence of fecal calprotectin (r = -0.3) (p <0.05).Conclusion:Elevated serum concentration of IL-6 in AS is associated with clinical and laboratory markers of high inflammatory activity of the disease. The levels of IL-8 in the sera of AS patients were negatively correlated with the concentration of fecal calprotectin. Data on the relationship of IL-8 with the activity of the pathological process in AS require further study.Disclosure of Interests:Elena Aleksandrova: None declared, Alexander Novikov: None declared, Polina Kulakova: None declared, Aleksey Dorofeev: None declared, Nadezhda Savenkova: None declared, Evgeniy Volnukhin: None declared, Anton Kovshik: None declared, Galina Lukina Speakers bureau: Novartis, Pfizer, UCB, Abbvie, Biocad, MSD, Roche