Comparison of ozone therapy and routine medical treatment effect on disease severity and serum level changes of IL-33 in patients with remitting-relapsing multiple sclerosis: A parallelled randomised clinical trial

Introduction IL-33 is an inflammatory cytokine involved in the pathogenesis of Multiple sclerosis (MS) as an autoimmune inflammatory disease. Ozone therapy has been shown to improve the symptoms of the disease in previous studies. Given the limitations of previous studies, we investigated the effect of adding ozone therapy to conventional medical treatment in remitting-relapsing multiple sclerosis (RR-MS) patients from the points of disease severity and blood levels of IL-33. Methods This clinical trial was performed on 66 RR-MS patients, among whom 55 finished the study. The patients were divided randomly into two groups; one group (intervention) received ozone therapy in addition to the routine medical treatment, and the other group (control) received only routine medical treatment. The level of IL-33 was measured by ELISA, and the severity of the disease was measured by an expanded disability status scale (EDSS) in all patients before and after the treatment. Finally, the relationship between the serum levels of IL-33 and EDSS score with the type of treatment was evaluated. The research project was registered at the International Center for the Registration of Clinical Trials in Iran (IRCT20171105037262N3). Results Our findings showed that the serum levels of IL-33 in the ozone plus medical-treated group significantly decreased compared to the medical-treated group (P<0.001). The EDSS score also decreased significantly in the ozone plus medical-treated group compared to the medical-treated group (P=0.019). Conclusion Ozone therapy reduces the severity of RR-MS. Such an effect may be influenced by modifying IL-33 levels.