Uric acid levels in sera from patients with multiple sclerosis

Abstract

The levels of uric acid (UA), a natural peroxynitrite scavenger, were measured in sera from 240 patients with multiple sclerosis (MS) and 104 sex- and age-matched control patients with other neurological diseases (OND). The mean serum UA concentration was lower in the MS than in the OND group, but the difference did not reach the level of statistical significance (P = 0.068). However, the mean serum UA level from patients with active MS (202.6 + 67.1 mumol/l) was significantly lower than that in inactive MS patients (226.5 + 78.6 mumol/l; P = 0.046) and OND controls (P = 0.007). We found a significant inverse correlation of serum UA concentration with female gender (P = 0.0001), disease activity (P = 0.012) and duration (P = 0.017), and a trend towards an inverse correlation with disability as assessed by EDSS score, which did not reach statistical significance (P = 0.067). Finally, multivariate linear regression analyses showed that UA concentration was independently correlated with gender (P = 0.0001), disease activity (P = 0.014) and duration of the disease (P = 0.043) in MS patients. These findings suggest that serum UA might serve as a possible marker of disease activity in MS. They also provide support to the potential beneficial therapeutic effect of radical-scavenging substances in MS.

Cerebrospinal fluid and serum uric acid levels in patients with multiple sclerosis

“…In accordance with these findings, we have previously demonstrated significantly lower mean serum UA concentrations in MS patients compared with NIND controls (21). Female gender correlated inversely with both serum UA concentrations in our previous study (21), and with CSF UA concentrations in this study. Thus, it could be presumed that the reduced antioxidant capacity, as assessed by the lower CSF UA concentrations in female patients with MS, could partially explain the predominance of females with MS. On the other hand, CNS inflammation in the active phase of the disease could lead to the consumption of UA and a reduction of the UA scavenger activity.…”

“…Additionally, lower serum UA concentrations have been found in patients with optic neuritis (34), and in patients with other forms of the clinically isolated syndrome (CIS) (23). In accordance with these findings, we have previously demonstrated significantly lower mean serum UA concentrations in MS patients compared with NIND controls (21). Female gender correlated inversely with both serum UA concentrations in our previous study (21), and with CSF UA concentrations in this study.…”

“…Thus, it could be presumed that the reduced antioxidant capacity, as assessed by the lower CSF UA concentrations in female patients with MS, could partially explain the predominance of females with MS. On the other hand, CNS inflammation in the active phase of the disease could lead to the consumption of UA and a reduction of the UA scavenger activity. In our previous study of 240 patients with MS, we found significantly lower serum UA concentrations in patients with clinical symptoms and/or MRI signs of disease activity (21).…”

“…Whether the reduction of UA concentrations in patients with active MS, as found in some studies (21,29), is a cause or a consequence of disease activity remains unclear. It may be speculated that patients with active MS may have intrinsically reduced antioxidant capacity, which contributes to the tissue damage in MS. Epidemiological studies have found MS and gout, characterized by increased UA concentrations in serum, are mutually exclusive (17).…”

“…Protective effects of UA on the blood-CNS barrier in EAE have been also demonstrated (20). Significantly lower serum UA concentrations were found in MS patients compared to controls in some studies (21)(22)(23), and low serum UA concentrations have been suggested to be a potential marker of disease activity in some MS patients (24).…”