A complex cytokine network, adipokines, abnormal metabolites, acute phase reactants and the complement system regulate the propagation and progression of inflammation-associated synovitis, cartilage catabolism and bone destruction andconsequently play major roles in arthritis pathophysiology.Synovial tissues (e.g., cartilage and bone)arefrequently degraded in diseases like RA and OAbecause the function of the complement system is compromised. Uncontrolled activation of the complement pathway contributes to the pathogenesis of several autoimmune and inflammatory conditions that include musculoskeletal diseases like Rheumatoid Arthritis (RA) and Osteoarthritis (OA). The complement system comprises more than 30 plasma and membrane-bound proteins.It can be activated through three pathways: the classical, the alternative and the lectin pathways. Normally the complement system is tightly regulated so that host cells are protected againstoff-target effects or tissue damage whilst being exposed to a pathogenic organism. It is an integral component of the innate immune system that is inextricably linked with the adaptive immune system.

Functionally, the complement system serves to protect the host from pathogens.

Membrane pro mac