RT Journal Article SR Electronic T1 Higher Expression of Whole Blood MicroRNA-21 in Patients with Ankylosing Spondylitis Associated with Programmed Cell Death 4 mRNA Expression and Collagen Cross-linked C-telopeptide Concentration JF The Journal of Rheumatology JO J Rheumatol FD The Journal of Rheumatology SP jrheum.130515 DO 10.3899/jrheum.130515 A1 Chun-Huang Huang A1 James Cheng-Chung Wei A1 Wei-Chiao Chang A1 Shang-Yan Chiou A1 Chia-Hsuan Chou A1 Yu-Jie Lin A1 Pei-Hsuan Hung A1 Ruey-Hong Wong YR 2014 UL http://www.jrheum.org/content/early/2014/04/28/jrheum.130515.abstract AB Objective Bone loss is a recognized feature of ankylosing spondylitis (AS). The binding of microRNA-21 (miR-21) to programmed cell death 4 (PDCD4) could inhibit the expression of PDCD4 and further induce the activation of osteoclasts. In the present study, we compared the difference in miR-21 expression between patients with AS and healthy controls, and evaluated the relationships of miR-21, PDCD4 mRNA, and bone erosion in patients with AS. The influences of nonsteroidal antiinflammatory drugs (NSAID) and disease-modifying antirheumatic drugs (DMARD) on the expressions of miR-21 and PDCD4 mRNA in patients with AS were also assessed. Methods Whole blood miR-21 and PDCD4 mRNA expression were evaluated by quantitative real-time PCR among 122 patients with AS and 122 healthy controls. The serum level of collagen cross-linked C-telopeptide (CTX) was measured using ELISA. Results When compared to controls, patients with AS had significantly higher levels of miR-21, PDCD4 mRNA, and CTX. MiR-21 expression was negatively correlated with PDCD4 mRNA expression in patients with AS who were taking neither NSAID nor DMARD. Interestingly, signifi - cantly positive correlations between miR-21 expression with PDCD4 mRNA expression (r = 0.33, p = 0.01) and CTX level (r = 0.44, p < 0.01) were observed in patients with AS who were taking sulfasalazine. Positive correlations of miR-21 and CTX level were also observed in AS patients with disease duration < 7.0 years (r = 0.36, p = 0.004) and active disease (r = 0.42, p = 0.001). Conclusion The expression of miR-21 might have a role in the development of AS.