The role of human xanthine oxidoreductase (HXOR), anti-HXOR antibodies, and microorganisms in synovial fluid of patients with joint inflammation

Abstract

This work is to investigate the levels of human xanthine oxidoreductase (HXOR), its antibodies, and microorganisms in synovial fluid of patients with untreated rheumatoid joint diseases. Synovial fluids were collected from sixty-four patients with rheumatoid joint diseases. Sixty-four age-matched individuals were included as control. Xanthine oxidoreductase (XOR) proteins level and anti-XOR antibodies were determined in the blood and synovial fluid, using human XOR as antigen, by enzyme-linked immunosorbent (ELISA) assay. Synovial fluids were cultured for bacteria and fungi. The titers of XOR protein in the synovial fluid of patients with rheumatoid arthritis were 90.43 ± 23.37 μg/ml (mean ± SD, n = 29) and up to 62.42 ± 8.74 μg/ml (mean ± SD, n = 35) in other joint inflammation. Anti-HXOR antibodies titers in patients were 167.72 ± 23.64 μg/ml, n = 64, which was significantly higher in rheumatoid arthritis patients. The results indicated that anti-HXOR antibodies in synovial fluids have a protective role as high concentrations against XOR were detected in inflammatory arthritis. These antibodies play a role in eliminating XOR from synovial fluids. However, immune complex formation could activate complement and participate in propagating the inflammatory cycle. Synovial aspirate ordinary microbial cultures were negative for any bacteria or fungi, but that does not exclude organisms of special culture requirements.

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

“…The highest percentage of immune complexes IgG-XOR was recorded in mechanical infections and the hemarthrosis category, and was close to the rest of the groups. These results confirm our previous study (10,35) where the presence of these antibodies was well discussed. Al Muhtaseb et al (35) indicated that anti-XO antibodies in SF possess a protective role in inflammatory arthritis, where they play a role in eliminating XOR from SF.…”

“…These results confirm our previous study (10,35) where the presence of these antibodies was well discussed. Al Muhtaseb et al (35) indicated that anti-XO antibodies in SF possess a protective role in inflammatory arthritis, where they play a role in eliminating XOR from SF. However, immune complexes could activate complement and participate in propagating the inflammatory cycle.…”