Role of Plasma MicroRNAs 145 and 484 in Diagnosis of Multiple Sclerosis, Disease Activity and the Transition from Relapsing Remitting Multiple Sclerosis to Secondary Progressive Multiple Sclerosis

. Abstract Background: There is a growing need for biomarkers that can help in early diagnosis of multiple sclerosis (MS) and in recognizing patients with MS activity. Moreover, many studies are recently focusing on biomarkers that may help in diagnosis of the transition from relapsing remitting multiple sclerosis (RRMS) to secondary progressive multiple sclerosis (SPMS). Circulating microRNAs (miRNAs) are now considered promising biomarkers. Objectives: Studying the role of plasma miRNA-145 and miRNA-484 in the diagnosis of MS, disease activity and in diagnosing the transition from RRMS to SPMS. Patients and Methods: Forty-six subjects of both sexes were included, 31 patients with MS ) 21 with RRMS, 8 with SPMS and Two patients with primary progressive multiple sclerosis (PPMS)) and 15 healthy controls. Expression analysis of plasma miRNAs; miR-145 and miR-484 were assessed by real-time quantitative polymerase chain reaction (PCR) after miRNA extraction. Results: MicroRNAs 145 and 484 could significantly discriminate between MS cases and controls, with best cut-off values > 0.6 and > 1.7 respectively. They could also significantly discriminate between active and inactive MS cases, with best cut-off values > 0.8 and > 2 respectively. Plasma miRNA-145 could discriminate between RRMS and SPMS cases, with best cut-off value ≤1.4. Conclusion: Plasma miRNAs 145 and 484 might be used as promising biomarkers for early diagnosis of MS and in diagnosis of disease activity. Plasma miRNA-145 could be also helpful in diagnosis of the transition from RRMS to SPMS.