title: Correlation between plasma, synovial fluid and articular cartilage Interleukin-18 with radiographic severity in 33 patients with osteoarthritis of the knee.
abstract: Osteoarthritis (OA) is a complex disease characterized by cartilage degeneration, secondary synovial membrane inflammation and subchondral bone changes. In recent years, many studies have confirmed that interleukin-18 (IL-18) is involved in the inflammatory process of inflammatory joint diseases. In the present study, we investigated IL-18 levels in plasma, synovial fluid and articular cartilage of patients with primary knee OA (n = 33) to analyze their relationship with radiographic severity. Compared to healthy controls (n = 15), OA patients had higher plasma and synovial fluid IL-18 concentrations(45.8 ± 22.1 vs. 23.7 ± 13.6 pg/ml, P<0.001 and 75.2 ± 40.1 vs. 28.3 ± 11.6 pg/ml, P<0.001) as measured by enzyme-linked immunosorbent assay. Also,the percentage of immunofluorescent IL-18 positive cells in articular cartilage was significantly increased in OA compared to controls (46.5 ± 10.3 vs. 2.9 ± 1.7, P<0.001). Moreover, plasma, synovial fluid and articular cartilage IL-18 significantly positively correlated with radiographic severity, respectively (r = 0.663, P<0.001, r = 0.56, P = 0.001 and r = 0.884, P<0.001). Subsequent analysis revealed that plasma, synovial fluid and articular cartilage IL-18 levels positively correlated with each other (r = 0.632, P<0.001, r = 0.489, P = 0.004 and r = 0.620, P<0.001). These data suggested that plasma, synovial fluid and articular cartilage IL-18 levels were significantly increased in OA patients, and these elevated levels were positively correlated with radiographic severity. Accordingly, our study supports the role of IL-18 in the pathophysiology of OA.
authors: Youhua
authors: Y
authors: Wang
authors: Dawei
authors: D
authors: Xu
authors: Long
authors: L
authors: Long
authors: Xiaolong
authors: X
authors: Deng
authors: Ran
authors: R
authors: Tao
authors: Guicheng
authors: G
authors: Huang
mesh_terms: D000368:Aged; D002358:Cartilage, Articular / Q000737:chemistry*; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005455:Fluorescent Antibody Technique; D006801:Humans; D020382:Interleukin-18 / Q000032:analysis*; D008297:Male; D008875:Middle Aged; D020370:Osteoarthritis, Knee / Q000000981:diagnostic imaging* / Q000473:pathology*; D010949:Plasma / Q000737:chemistry*; D011859:Radiography; D013582:Synovial Fluid / Q000737:chemistry*
chemical_list: C000589760:IL18 protein, human; D020382:Interleukin-18
references: Arterioscler Thromb Vasc Biol. 2005 Jun;25(6):1268-73
references: 15790931
references: J Rheumatol. 2013 Jun;40(6):891-902
references: 23637319
references: Curr Opin Rheumatol. 2002 Sep;14(5):585-9
references: 12192260
references: J Orthop Res. 1992 Jan;10(1):58-61
references: 1727936
references: Osteoarthritis Cartilage. 2010 May;18(5):605-12
references: 20175979
references: Osteoarthritis Cartilage. 2012 Dec;20(12):1484-99
references: 22960092
references: J Invest Dermatol. 2005 Jun;124(6):1225-33
references: 15955098
references: Annu Rev Immunol. 2001;19:423-74
references: 11244043
references: Clin Rheumatol. 2006 Jul;25(4):448-52
references: 16362448
references: Bone. 2008 Jun;42(6):1102-10
references: 18374640
references: J Rheumatol. 1999 Sep;26(9):2002-14
references: 10493683
references: Osteoarthritis Cartilage. 2011 Jul;19(7):768-78
references: 21281726
references: J Invest Dermatol. 2003 Sep;121(3):502-9
references: 12925208
references: J Immunol. 2001 Jan 1;166(1):517-21
references: 11123331
references: J Clin Invest. 2001 Dec;108(12):1825-32
references: 11748266
references: Arthritis Res Ther. 2011 Mar 24;13(2):R52
references: 21435242
references: Ann Rheum Dis. 2005 May;64(5):735-42
references: 15834055
references: Acta Biomed. 2010 Sep;81(2):94-100
references: 21305873
references: Ann Rheum Dis. 1957 Dec;16(4):494-502
references: 13498604
references: Int J Mol Med. 2012 Oct;30(4):805-10
references: 22825306
references: J Exp Med. 1997 Mar 17;185(6):1005-12
references: 9091574
references: Br J Rheumatol. 1997 Nov;36(11):1151-60
references: 9402858
references: Lancet. 2011 Jun 18;377(9783):2115-26
references: 21684382
references: J Immunother. 2002 Mar-Apr;25 Suppl 1:S61-4
references: 12048352
references: J Immunol. 1999 Jan 15;162(2):1096-100
references: 9916738
references: Ann Rheum Dis. 2007 Nov;66(11):1411-8
references: 17502360
references: J Biol Chem. 2001 Feb 9;276(6):3820-6
references: 11056157
references: Arthritis Rheum. 2003 Feb;48(2):339-47
references: 12571842
references: Ann Rheum Dis. 2004 Nov;63(11):1393-8
references: 15479888
references: Blood. 2002 Feb 15;99(4):1289-98
references: 11830478
references: Curr Opin Immunol. 2000 Feb;12(1):59-63
references: 10679398
references: Zhong Nan Da Xue Xue Bao Yi Xue Ban. 2006 Dec;31(6):862-5
references: 17213584