Micro-RNA 18b and interleukin 17A profiles in relapsing remitting multiple sclerosis

Background: The involvement of micro RNAs (miRNAs) in multiple sclerosis (MS) has been recently explored. Up-regulated miRNAs may play critical roles in MS pathogenesis and may be used as a signature for MS. Besides, the role of inflammatory cytokines has been long established with recent focus on interleukin-17 (IL-17).

Objective: To evaluate the level of expression miR-18b in relation to IL-17A in relapsing remitting (RR) MS patients during relapse and remission SUBJECTS AND METHODS: Twenty-eight RRMS patients and 26 age and sex matched control subjects were included. Serum miR-18b was assessed by quantitative real-time PCR, and serum level of IL-17A was measured by ELISA.

Results: Serum miR-18b expression was higher in relapse compared with remission and with controls (24.8 ± 21.91 vs 2.49 ± 0.97 vs 1 ± 0.36 respectively; P < 0.001). Serum IL-17Awas higher in MS patients during relapse than during remission and controls (8.49 ± 1.26 vs 5.78 ± 2.27 vs 4.18 ± 2.13, respectively; P < 0.001). No correlations existed between miR-18 and IL-17 in MS patients during relapse (r = 0.35; P = 0.22) or remission (r = 0.340; P = 0.234).

Conclusion: Upregulation of miR-18 during relapse in patients with RRMS points to a possible contribution to the pathogenesis of the inflammatory process in MS. The lack of a significant correlation between upregulated miR-18 and IL-17A implicates that the influence of miR-18 may be exhibited via another inflammatory pathway.