Vitamin D deficiency is associated with disability and disease progression in multiple sclerosis patients independently of oxidative and nitrosative stress.

The aim of this study was to assess vitamin D status in patients with multiple sclerosis (MS) and to evaluate whether it was associated with oxidative and nitrosative stress (O&NS) markers and disability. This study included 137 patients with MS and 218 healthy controls. The markers evaluated were serum levels of 25-hydroxyvitamin D, lipid hydroperoxides, advanced oxidation protein products (AOPP), nitric oxide metabolites (NOx), and total radical-trapping antioxidant parameter TRAP/UA. Patients with 25(OH)D<20ng/mL showed higher EDSS (p=0.016), MSSS (p=0.005) and lower AOPP (p=0.046) than those with 25(OH)D≥20ng/mL. After the binary logistic regression analyses, EDSS and MSSS remained significantly associated with vitamin D deficiency. We showed that lower levels of 25(OH)D were associated with higher EDSS and MSSS independently of variables such as O&NS, age, sex, body mass index, ethnicity, MS therapy, use of interferon beta, and clinical forms of MS (odds ratio: 1.380, 95% confidence interval 1.030-1.843, p=0.031). Moreover, the study showed an association between serum levels of 25(OH)D and EDSS (r2=0.115, p=0.002), demonstrating that 25(OH)D may contribute with 11.5% of increase in EDSS. Our results suggest that vitamin D deficiency may be considered one of the predictors of the disability in MS patients, independently of their redox status and influence the progression of disability in MS.

Disease progression and oxidative stress are associated with higher serum ferritin levels in patients with multiple sclerosis.

Hyperferritinemia and oxidative stress have been implicated in the pathogenesis of multiple sclerosis (MS). The aim of the present study was to evaluate the serum levels of ferritin and to verify their association with oxidative stress markers and MS progression. This study included 164 MS patients, which were divided in two groups according to their levels of ferritin (cut off 125.6µg/L). Oxidative stress was evaluated by tert-butyl hydroperoxide-initiated chemiluminescence (CL-LOOH), advanced oxidation protein products (AOPP), carbonyl protein, nitric oxide metabolites (NOx), sulfhydryl groups of protein and total radical-trapping antioxidant parameter (TRAP). MS patients with elevated levels of ferritin showed higher disease progression (p=0.030), AOPP (p=0.001), and lower plasma NOx levels (p=0.031) and TRAP (p=0.006) than MS patients with lower ferritin levels. The multivariate binary logistic regression analysis showed that increased AOPP and progression of disease were significantly and positively associated with increase of ferritin. The combination of serum ferritin levels and oxidative stress markers were responsible for 13,9% in the disease progression. In conclusion, our results suggest that ferritin could aggravate oxidative stress in patients with MS and contribute to progression of disease.