title: Increase of uric acid and purine compounds in biological fluids of multiple sclerosis patients.
abstract: OBJECTIVE
  In this study, the concentrations of uric acid, purine profile and creatinine in samples of cerebrospinal fluid and serum of multiple sclerosis (MS) patients were measured by HPLC and compared with corresponding values recorded in patients without MS (cerebrospinal fluid) and healthy subjects (serum).
  
  
  METHODS
  All samples were deproteinized with ultrafiltration (which ensures minimal sample manipulation and efficient protein removal) and then assayed for the synchronous HPLC separation of uric acid, hypoxanthine, xanthine, inosine, adenosine, guanosine and creatinine.
  
  
  RESULTS
  The values of all compounds assayed were significantly higher in both biological fluids of MS patients with respect to values measured in controls. In particular, serum hypoxanthine, xanthine, uric acid and sum of oxypurines were, respectively, 3.17, 3.11, 1.23 and 1.27-fold higher in these patients than corresponding values recorded in controls (p<0.001).
  
  
  CONCLUSIONS
  Differently from what previously reported, we here demonstrate that all purine compounds, including uric acid, are elevated in biological fluids of MS patients. Reinforced by the trend observed for creatinine, this corroborates the notion of sustained purine catabolism, possibly due to imbalance in ATP homeostasis, under these pathological conditions. These results cast doubt on the hypothesis that uric acid is depleted in MS because of increased oxidative stress, rather suggesting that this disease causes a generalized increase in purine catabolism. As observed in other pathological states, uric acid, purine compounds and creatinine, can be considered markers of metabolic energy imbalance rather than of reactive oxygen species, even in MS.
authors.affiliation: Institute of Biochemistry and Clinical Biochemistry, Catholic University of Rome Sacro Cuore, Rome, Italy.
authors.forename: Angela M
authors.initials: AM
authors.lastname: Amorini
authors.forename: Axel
authors.initials: A
authors.lastname: Petzold
authors.forename: Barbara
authors.initials: B
authors.lastname: Tavazzi
authors.forename: Judith
authors.initials: J
authors.lastname: Eikelenboom
authors.forename: Geoffrey
authors.initials: G
authors.lastname: Keir
authors.forename: Antonio
authors.initials: A
authors.lastname: Belli
authors.forename: Gavin
authors.initials: G
authors.lastname: Giovannoni
authors.forename: Valentina
authors.initials: V
authors.lastname: Di Pietro
authors.forename: Chris
authors.initials: C
authors.lastname: Polman
authors.forename: Serafina
authors.initials: S
authors.lastname: D'Urso
authors.forename: Roberto
authors.initials: R
authors.lastname: Vagnozzi
authors.forename: Bernard
authors.initials: B
authors.lastname: Uitdehaag
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Lazzarino