title: Serum uric acid levels and leukocyte nitric oxide production in multiple sclerosis patients outside relapses.
abstract: BACKGROUND
  A number of studies found that patients with multiple sclerosis (MS) have low serum levels of uric acid. It is unclear whether this represents a primary deficit or secondary effect. Uric acid is a scavenger of peroxynitrite, which is the product of nitric oxide (NO) and superoxide. Because peripheral blood leukocyte NO production and NO metabolites in serum are raised in MS patients, associations might be expected between serum uric acid levels and peripheral NO production.
  
  
  METHODS
  Serum levels of uric acid and NO production by peripheral blood leukocytes were measured in 60 patients with MS without a relapse in the past 3 months, and 30 age- and sex-matched healthy controls. Uric acid was determined with the uricase PAP method, and NO production was assayed by measuring nitrite concentration in supernatants of lysed leukocytes.
  
  
  RESULTS
  Serum uric acid levels were not different between MS patients and controls. Compared to controls, patients with MS had significantly higher peripheral blood leukocytes nitrite concentrations (p<0.001). There was no correlation between leukocyte nitrite concentration and serum uric acid levels.
  
  
  CONCLUSIONS
  Our findings suggest that in MS patients there is no primary deficit in serum uric acid. NO production by peripheral blood leukocytes is increased, but there is no association with serum uric acid levels.
authors.affiliation: Department of Neurology, Academisch Ziekenhuis Groningen, Hanzeplein 1, 9713 GZ Groningen, The Netherlands.
authors.forename: Jop P
authors.initials: JP
authors.lastname: Mostert
authors.forename: Geeta S M
authors.initials: GS
authors.lastname: Ramsaransing
authors.forename: Dorothea J
authors.initials: DJ
authors.lastname: Heersema
authors.forename: Marco
authors.initials: M
authors.lastname: Heerings
authors.forename: Nadine
authors.initials: N
authors.lastname: Wilczak
authors.forename: Jacques
authors.initials: J
authors.lastname: De Keyser
mesh_terms: D000328:Adult; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D016899:Interferon-beta / Q000627:therapeutic use; D007962:Leukocytes / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D008875:Middle Aged; D009103:Multiple Sclerosis / Q000097:blood* / Q000188:drug therapy / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D012016:Reference Values; D018709:Statistics, Nonparametric; D014527:Uric Acid / Q000097:blood*
chemical_list: D014527:Uric Acid; D009569:Nitric Oxide; D016899:Interferon-beta