Comparison of xanthine oxidase levels in synovial fluid from patients with rheumatoid arthritis and other joint inflammations.
OBJECTIVE
To search whether xanthine oxido-reductase (XOR) present in the synovium is also liberated, to determine its activity in synovial fluid and to establish a possible relationship between XOR levels in rheumatoid arthritis (RA) and non-RA patients.


METHODS
This study was carried out in the Laboratory of Immunology, University Ferhat Abbas, Setif, Algeria from 2001-2008. This study is a retrospective controlled study matching cases with RA to non rheumatoid joint inflammations. Synovial fluid (SF) samples were collected with consent of the patients, at Setif University Hospital, from adults suffering from RA (n=36) or only with joint inflammations (n=52). After its detection in SF with indirect enzyme-linked immunosorbent assay (ELISA) and dot-immunobinding, using anti-bovine XOR as first antibodies, XOR was assayed with capture ELISA.


RESULTS
Xanthine oxidoreductase is found in all studied SF. Capture ELISA showed levels up to 0.762 and 0.143 mg/mL in SF of RA and other joint inflammations patients, respectively. In most cases, more than 50% of synovial XOR is present as oxidase form. Positive correlation was observed between enzyme level and the disease severity since RA patients had a significantly high enzyme amount compared to patients with other less severe arthritic pathologies.


CONCLUSIONS
These results suggest that the enzyme could well be involved in joint inflammation probably by producing reactive oxygen species.
Hanachi
Nadjet
N
The Laboratory of Applied Biochemistry, Department of Biology, University of Bordj Bouarriridj, Setif, Algeria.
Charef
Noureddine
N
Baghiani
Abderrahmane
A
Khennouf
Seddik
S
Derradji
Yacine
Y
Boumerfeg
Sabah
S
Harzallah
Daoud
D
Arrar
Lekhmici
L
D000328:Adult; D001168:Arthritis / Q000097:blood / Q000175:diagnosis; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis; D015415:Biomarkers / Q000097:blood; D016022:Case-Control Studies; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D015151:Immunoblotting; D008297:Male; D008875:Middle Aged; D010003:Osteoarthritis / Q000097:blood / Q000175:diagnosis; D011379:Prognosis; D012189:Retrospective Studies; D012720:Severity of Illness Index; D013582:Synovial Fluid / Q000201:enzymology*; D014969:Xanthine Oxidase / Q000032:analysis / Q000378:metabolism*
D015415:Biomarkers; D014969:Xanthine Oxidase