RESUMEN
Multiple sclerosis (MS) is a chronic inflammatory disease of the central nervous system (CNS). Considering how vitamin B12 or cobalamin affects the immune system, especially inflammation and the formation of the myelin sheath, it appears as a complementary therapy for MS by affecting some signaling pathways. Recently diagnosed MS patients were divided into two groups (n=30). One group received interferon-beta (IFN-ß or Avonex), and another received IFN-ß+B12 for six months. Blood samples were taken before and after treatments. Interleukin (IL)-10 and osteopontin (OPN) levels in the plasma were determined by the enzyme-linked immunosorbent assay (ELISA) method, and the expression of microRNA (miR)-106a, miR-299a, and miR-146a by real-time PCR. IFN-ß neither changed the IL-10 plasma levels nor miR106a and miR-299a expression, but it led to a remarkable decrease in OPN concentration and enhancement in let-7c and miR-146a expression. There was a significant decrease in IL-10, OPN plasma levels, miR-106a expression, and a substantial increase in let-7c and miR-146a expression in IFN-ß+B12, treated group. There was no correlation between IL-10 and OPN with related miRNAs in the two treatment groups. Our study indicated that B12 could be a complementary treatment in MS that may influence the disease improvement.