title: Elevated nitric oxide production in patients with primary Sjögren's syndrome.
abstract: Nitric oxide (NO) production is elevated in patients with inflammatory disorders. We have previously shown increased NO production in patients with rheumatoid arthritis and systemic lupus erythematosus. In this study we used nitrite and citrulline levels as surrogate markers of NO production in patients with primary Sjögren's syndrome (SS) and measured their levels by spectrophotometry. Fifteen patients and 15 age- and sex-matched controls were studied. Mean nitrite levels in patients were 582.3+/-208.3 nmol/ml, but those in controls were significantly lower, at 203.2-106.9 nmol/ml (p<0.001). Citrulline levels were 2820.4+/-933.9 nmol/ml in patients and were significantly higher than 217.4+/-144.8 nmol/ml, the levels in controls (p<0.0001). Mean levels of both nitrite and citrulline were significantly higher in patients with arthritis than in those who had no joint manifestations (p<0.05). There was no correlation between NO production and other variables, such as age, disease duration, drug therapy and antinuclear antibodies or rheumatoid factor positivity. Increased NO production may be partly a reflection of the presence of arthritis in five patients. It is concluded that there is increased NO production in patients with primary SS, especially if they have associated arthritis.
authors.affiliation: Department of Internal Medicine, Postgraduate Institute of Medical Education and Research, Chandigarh, India. awanchu@glide.net.in
authors.forename: A
authors.initials: A
authors.lastname: Wanchu
authors.forename: M
authors.initials: M
authors.lastname: Khullar
authors.forename: A
authors.initials: A
authors.lastname: Sud
authors.forename: P
authors.initials: P
authors.lastname: Bambery
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D002956:Citrulline / Q000097:blood; D003937:Diagnosis, Differential; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000096:biosynthesis* / Q000097:blood; D012720:Severity of Illness Index; D012859:Sjogren's Syndrome / Q000097:blood* / Q000175:diagnosis; D013053:Spectrophotometry
chemical_list: D015415:Biomarkers; D002956:Citrulline; D009569:Nitric Oxide