Inflammation Parameters, Xanthine Oxidase and Anti-Xanthine Oxidase Antibodies in Synovial Fluid of Patients Suffering from Arthritis

Abstract

Objective: Rheumatoid arthritis (RA) is an autoimmune disease where sera and synovial fluid (SF) of suffering patients contain immune complexes formed from autoantibodies to several proteins. SF from humans with joint diseases was examined for the presence of some inflammatory parameters and autoantibodies.Materials and Methods: Antibodies in their free and complex forms were assayed by indirect ELISA. The immunoprecipitation technique was used to evaluate total IgG and IgM and complement. Results:The results showed that most RA SF was anti-ASLO negative, but they were CRP positive. Levels of complement components (C3 and C4) were highest in the group of mono-/oligo-arthritis and lowest in RA. The results showed that xanthine oxidase (XO) presence and activity were important in SF of RA patients. Moreover, free and complex anti-XO antibodies were detected in all SF with different titers throughout the groups of patients where IgG was lower than IgM. Conclusion:The studied parameters of inflammation and auto-antibodies especially against XO could serve as an evaluation of the severity of joint inflammation and in RA pathogenesis understanding.