Down-regulation of RORA gene expression in the blood of multiple sclerosis patients.

Multiple sclerosis (MS) is an autoimmune disease characterized by recurrent episodes of demyelination and loss of oligodendrocytes. The demyelination process is caused by various subsets of CD4+ T cells with a Th1 and Th17 phenotype. The retinoid acid-related orphan receptor A (RORA) is expressed in Th17 cells and promote Th17 differentiation. In this study, we compared the expression level of RORA gene in the blood of 50 relapsing-remitting MS (RRMS) patients who were treated with IFN-β and 50 healthy controls by TaqMan Quantitative Real-Time PCR.We found that RORA expression was significantly down-regulated in MS patients compared with controls (P= 0.006). However, there was no significant correlation between RORA gene expression and Kurtzke Expanded Disability Status Scale (EDSS). Our findings suggest a possible contribution of IFN-β in the downregulation of RORA. In addition, RORA downregulation may be a potential indicator of positive response to interferon beta treatment of multiple sclerosis patients.