Investigation of miR-146a expression profiles in fecal samples of patients with multiple sclerosis for early diagnosis and treatment

Introduction: Recent research into multiple sclerosis (MS) has focused on the role of microRNAs (miRNAs) in the development of the disease. This study was designed to analyze miR-146a expression in whole blood and fecal samples of patients with MS. The study aimed to analyze clinical data using the miR-146a expression values obtained. Subjects and Methods: This study included patients with relapsing–remitting MS (RRMS) (n = 53), clinically isolated syndrome (CIS) (n = 15), and healthy controls (n = 26). Total RNA was isolated from the participants' whole blood and fecal samples. RNA extraction was performed using QIAamp RNA Blood Mini Kits for blood samples and RNeasy PowerMicrobiome Kits for feces. miR-146a expressions were studied using real-time polymerase chain reaction. Finally, relative expression was correlated with clinicopathologic factors. Results: MiR-146a expression was significantly decreased in the whole blood (P < 0.001) and fecal samples (P = 0.036) of patients with RRMS. There was no significant difference in the miR-146a expression rate between patients with CIS and controls. Moreover, the miR-146a expression level in patients with RRMS was decreased compared with those with CIS (P < 0.001). A significant association was determined between miR-146a expression and sex in blood samples. When sex stratification was applied to expression values obtained from fecal samples, miR-146a expression was downregulated only in females (P = 0.008). Discussion: miRNAs play an essential role in maintaining the stable course of MS, and this process has some sex-specific differences. Expression of fecal miR-146a may be used as a biomarker to diagnose and predict prognosis in patients with RRMS.