Overexpression of miR-31 in Peripheral Blood Mononuclear Cells (PBMC) from Patients with Ankylosing Spondylitis.

Background: miRNAs play vital roles in regulating immunologic functions and autoimmunity. However, the levels of miR-31, miR-155, miR-16, and miR-181a have not been explored in AS, but were verified to play vital roles in other immunological diseases. The aim of our study was to examine whether the expressions of miR-31, miR-155, miR16, and miR-181a are abnormal in AS. Material/ Methods: Real-time transcription-polymerase chain reaction analysis (RT-PCR) was used to determine the expression of miR-31, miR-155, miR-16, and miR-181a in peripheral blood mononuclear cells (PBMC) from 40 patients with AS and 40 healthy controls. Results: The expression of miR-31 was increased in AS patients compared with healthy controls (p=0.001). Furthermore, we detected no significant differences in the expressions of miR-155, miR-16, and miR-181a between AS patients and healthy controls. However, the expression levels of the 4 miRNAs were all significantly different between less active AS and more active AS, with higher levels in more active AS. Moreover, no significant correlations were found between the 4 miRNAs levels with the clinical characteristics in the patients with AS. Interestingly, the expression levels of miR-31, miR-155, and miR-16 in PBMCs were significantly positively correlated with the ESR in new AS patients but not old AS patients. Conclusions: Our results suggest that miR-31 is overexpressed in PBMCs of AS patients. Furthermore, miR-31, miR-155, miR16 and miR-181a may be associated with AS disease activity.