Serum nitrate and nitrite levels in patients with rheumatoid arthritis, ankylosing spondylitis, and osteoarthritis

Abstract

Objective: To assess and compare serum nitrate and nitrite levels in patients with ankylosing spondylitis (AS), rheumatoid arthritis (RA), and osteoarthritis (OA). Methods: Thirty five patients with RA, 32 patients with AS, and 36 patients with OA were entered into this study. In addition, 30 healthy volunteers acted as a control group. Concentrations of nitrate and nitrite in serum were determined by direct and indirect Griess reactions. C reactive protein and erythrocyte sedimentation rate levels were determined as markers of systemic activity of disease (SAD) in RA and AS groups. Results: Serum nitrate and nitrite levels were found to be higher in patients with AS and RA than in the OA group (p<0.01). In addition, serum nitrate and nitrite levels were higher in all three groups than in the control group (p<0.01). Moreover, serum nitrate and nitrite levels were higher in patients who had SAD than in those who had not in the RA and AS groups (p<0.01 and p<0.05, respectively), and there was a correlation between serum nitrate and nitrite concentrations and SAD variables in patients with RA (Spearman's r s =0.414, p<0.05 and r s =0.408, p<0.05, respectively) and AS (r s =0.421, p<0.05 and r s =0.412, p<0.05, respectively). Conclusion: The findings suggest that nitrate and nitrite production is enhanced in patients with inflammatory arthritis compared with OA. In addition, serum nitrate and nitrite levels are enhanced in patients with RA, AS, and OA compared with healthy subjects. Furthermore, there is a correlation between the SAD variables and serum nitrate and nitrite levels in patients with RA and AS. P revious studies on nitric oxide (NO), which is an inorganic, gaseous free radical, produced by the enzyme nitric oxide synthase (NOS), have suggested that it has several physiological roles, including the regulation of platelet function, neurotransmission, and the killing of intracellular pathogens.

Increased Serum Sialic Acid Levels in Primary Osteoarthritis and Inactive Rheumatoid Arthritis

“…In the present study, we preferred to measure the CC and TT levels rather than more common oxidative damage markers such as nitrite, nitrate and lipid peroxidation. The reason was that nitrite, nitrate and lipid peroxidation have already been reported to be increased in RA and OA (Kaur and Halliwell 1994;Hilliquin et al 1997;Novaes et al 1997;Ersoy et al 2002;Paredes et al 2002;Karan et al 2003;Ostalowska et al 2005Ostalowska et al , 2007Sahin et al 2006). …”

High pre-transplant serum nitrate levels predict risk of acute steroid-refractory graft-versus-host disease in the absence of statin therapy

“…10 Excessive levels of NO are produced by the inducible isoform of NOS (iNOS) in numerous cell types including immune effector cells. 11 Furthermore, elevated iNOS-derived NO levels have been demonstrated in various autoimmune diseases 12 as well as in solid organ allograft rejection. 13 In the setting of allogeneic SCT NO was shown to facilitate engraftment and iNOS inhibitors were reported to reduce mortality caused by experimental GVHD.…”

Oxidative stress and calcium-phosphorus levels in Rheumatoid arthritis

“…Many investigators have focussed on oxidative stress since last few years and suggest that RA patients are more prone to lipid peroxidation (3). Growing evidences implicate nitric oxide (NO · ) in immune regulations, inflammation, autoimmunity and arthritis (4,5). Antioxidants such as vitamin E and vitamin C are highly effective at mopping up free radicals (6).…”