Natalizumab Modifies Catecholamines Levels Present in Patients with Relapsing-Remitting Multiple Sclerosis

Aims: The main aim of this study was to verify the effect of natalizumab on the levels of circulating catecholamines and indolamine and their possible relation with MS. Methods: For this purpose, 12 healthy individuals (control group) and 12 relapsing-remitting multiple sclerosis patients (RR-MS) were selected. The patients were treated with 300 mg of natalizumab during 56 weeks (1 dose/4 weeks) (MS-56). This selection was based on the McDonalds revision criterion and scheduled to star treatment with natalizumab. Blood samples were taken before treatment (basal level) and after 56 weeks of using natalizumab. Melatonin was measured in serum and in plasma, catecholamines (dopamine, epinephrine, and norepinephrine), carbonylated proteins, 8-hydroxy-2' deoxyguanosine (8OH-dG) and the ratio reduced glutathione/oxidised glutathione (GSH/GSSG). Results: The epinephrine and dopamine levels diminished in the basal group with respect to the control and did not recover normal levels with the treatment. The melatonin was decreased in RR-MS patients and went back to its normal levels with natalizumab. Norepinephrine was increased in RR-MS and decreased in MS-56 until it equalled the control group. Conclusion: Natalizumab normalizes altered melatonin and norepinephrine levels in MS.