The Relationship Between the Multiple Sclerosis and Endogenous Antioxidan Serum Uric Acid

Fatma Candan; Nihal Işık; İlknur Aydın Cantürk; Zahide Yılmaz; Reyhan Gürer; Nüket Yıldız

Fatma Candan¹, Nihal Işık¹, İlknur Aydın Cantürk¹, Zahide Yılmaz², Reyhan Gürer³, Nüket Yıldız¹

¹Neurology Clinic, Ministry Of Health, Goztepe Education And Research Hospital, İstanbul, Turkey
²Evliya Celebi State Hospital, Kutahya, Turkey
³State Hospital, Tuzla, İstanbul

Keywords: uric acid, peroxynitrite, multiple sclerosis

Abstract

OBJECTIVE: Peroxynitrite (PRN) is a strong oxidant capable of damaging tissues and cells, and plays a major role in the pathogenesis of multiple sclerosis (MS). Uric acid (UA) is the naturally occuring final product of the purine metabolism in humans and the most prominent endojen antioxidant in serum. Uric acid selectively binds and inactivates the PRN. Recent studies suggested that patients with multiple sclerosis (MS) have lower levels of serum UA.

To investigate the role of the endogenous antioxidant defence in MS pathogenesis, by determining the serum UA levels of the MS patients and, examining the relationships with demographic and clinical characteristics of the patients.

METHODS: Serum uric acid levels were determined in 206 MS patients (151 women) all in the remission period, and in 38 age and sex matched voluntary healthy subjects, served as a control group. Of the 206 patients; 159 had the relapsing-remitting (RR) type of the disease, 37 secondary progressive (SP) and 10 primary progressive (PP). Disability as assessed by EDSS (Expanded Disability Status Scale) score. In addition, during the follow up period (12 months), relapses were observed in 45 of the 206 patients. Serum UA levels and EDSS of the patients were also determined in the relapse period before the treatment and, compared with remission period.

RESULTS: In the overall MS group, serum UA levels were significantly lower than in controls (p<0.0001). Serum UA levels in both gender of MS patients were also significantly lower than in controls. No correlation was found between disease duration and serum UA levels in MS patients as a general group and also in both gender. Although in the overall MS group there was no significant relationship between the EDSS and UA, we found a significant inverse correlation of serum UA level in female and male gender with EDSS (p<0.05). The lowest mean UA level was found in patients with PPMS, but the difference among the MS subgroups did not reach statistical significance. The mean serum UA level of the MS group in the relapse period (n: 45), was significantly lower than that in remission period (p<0.0001), and EDSS of the patients were significantly higher than in remission period (p<0.0001).

CONCLUSION: Our findings showed that UA is primarily low in MS patients and might be used as an endojen antioxidant during the relapse period. This study highlights the need to investigate the possible benefits of higher levels of uric acid to clinical findings in MS patients.