Relationship between specific microRNAs in plasma and juvenile idiopathic arthritis

Abstract

Objective To investigate the potential possibilities of specific microRNA in plasma as novel biomarkers for the early diagnosis in juvenile idiopathic arthritis(JIA). Methods This research was be segmented into 4 stages.1. Screened candidate microRNAs: 5 candidate plasma microRNAs were detected by biochips of microRNAs, corresponding 5 JIA patients with onset of oligoarthritis, 5 JIA patients with onset of polyarthritis and 3 age-matched and sex-matched healthy controls individual.2. The feasibility of the microRNAs as novel biomarkers was validated by Real-time quantitative polymerase chain reaction (RT-PCR) in plasma on 80 JIA patients (43 oligoarthritis, 37 polyarthritis), 29 juvenile ankylosing spondylitis(JAS) patients and 30 healthy control individuals.3. The change of microRNAs was observed by RT-PCR in plasma from another 9 JIA patients before and 3 months after anti-rheumatic drug treatment.4. The correlation between the levels of candidate plasma microRNAs and clinical parameters of JIA patients was analyzed. Results Plasma concentrations of miR-16, miR-146a and miR-223 in JIA patients, including oligoarthritis and polyarthritis, were significantly higher than those in healthy subjects (all P 0.05). More importantly, it was found that the expression of miR-16 was considerably reduced in the post-treatment plasma samples when compared to the pre-treatment samples(P=0.061). In addition, the levels of miR-16 in JIA plasma inversely corrected with tender joint. Conclusions Plasma levels of miR-16 were well-discriminated between JIA patients and healthy subjects or JAS patients. It is suggested that plasma miR-16 might serve as a novel and potential biomarker for screening JIA. Furthermore, it might serve as a novel biomarker for joint inflammation but not specifically for differentiating the subtypes of JIA. Key words: MicroRNA; Juvenile idiopathic arthritis; Biomarker