The effect of natalizumab on disability score and relapse rate of multiple sclerosis patients: a prospective cohort study.

Multiple sclerosis (MS) is a progressive immune-related disorder of the central nervous system leading to destruction of myelin sheaths. Natalizumab is a humanized monoclonal antibody against the cell adhesion molecule α4-integrin which has been approved for treatment of relapsing forms of MS. This study aims at determining the effect of natalizumab on expanded disability status scale (EDSS) score and relapse rate of MS patients. Fifty MS patients participated in the present prospective cohort study. Twenty patients (Mean age ± SD: 33 ± 6.03) received natalizumab and 30 patients (Mean age ± SD: 36.83 ± 7.24) were under treatment with IFN-β (control group). Patients were followed-up during a 12-month period. EDSS score and clinical signs were assessed monthly. Significant decreases were detected in EDSS score in natalizumab treated patients compared with the controls in months 10, 11 and 12. EDSS score showed a significant decrease in 80% of natalizumab treated patients. Number of relapses was significantly lower in natalizumab treated patients compared with control group. Natalizumab is effective in improvement of disability and reduction of relapse rate in MS patients.