Elevated plasma and synovial fluid interleukin-8 and interleukin-18 may be associated with the pathogenesis of knee osteoarthritis

Abstract Purpose Osteoarthritis (OA) of the knee is a multifactorial degenerative disease typically defined as the ‘wear and tear’ of articular joint cartilage. However, recent studies suggest that OA is a disease arising from chronic low-grade inflammation. We conducted a study to investigate the relationship between chronic inflammatory mediators present in both the systemic peripheral blood system and localised inflammation in synovial fluid (SF) of OA and non-OA knees; and subsequently made direct comparative analyses to understand the mechanisms that may underpin the processes involved in OA. Methods 20-Plex proteins were quantified using Human Magnetic Luminex® assay (RD whilst IL-1B, TLR4, IL-1, and basigin (BSG) were the regulators of IL-4, IL-8, IL-10, IL-15, IL-18, IL-21, IL-27, MMP-1, and MMP-3 in the SF system. Conclusion The elevated plasma IL-8 and SF IL-18 may be associated with the pathogenesis of OA via the activation of MMP-3.