Thesis (Ph.D.) - Cairo University - Faculty of Medicine - Department of Rheumatology and Rehabilitation

Background:Cytokine-mediated immunity plays an important role in the pathogenesis of autoimmune diseases. Several studies have shown Interleukin-33 (IL-33) to be involved in the pathogenesis of various autoimmune diseases such as systemic lupus erythematosus , systemic sclerosis,ankylosing spondylitis, primary Sjogren{u2019}s syndrome and Behcet{u2019}s disease. Recent evidence suggests that IL-33, a newly found IL-1 family cytokine,exerted profound effects in human rheumatoid arthritis (RA) and experimental inflammatory arthritis. Aim of work:The aim of this study was to evaluate serum and synovial fluid IL33 levels in active RA patients and to investigate its possible association with disease activity, clinical and laboratory findings. Patients and methods: This study was conducted on 50 RA patients and 30 osteoarthritis (OA) patients serving as a control group. All patients were subjected to full history taking, clinical examination including Disease Activity Score 28 (DAS 28), laboratory investigations as well as plain radiographs of both hands and feet and chest x-ray. Bone erosion was evaluated using the modified Sharp Score (MSS). Matched serum and synovial fluid (SF) IL-33 levelswere measured by enzyme-linked immunosorbent assay. Results:Serum and synovial IL-33 levels were significantly higher in RA patients than in OA patients. Synovial IL33 level was significantly higher than the matched serum IL-33 level in RA patients. A statisticallyinsignificantassociation was found between serum and synovial IL-33 levels with ESR, CRP, tender joint count, swollen joint count, DAS28, disease duration, rheumatoid factor, anti-CCP antibody and MSS

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