Circulating miRNome profile in Behçet's Disease

Objective: Beh et’s syndrome (BS) is a rare systemic vasculitis whose pathogenesis is still unclear. Due to the lack of properly validated biomarkers, BS is often difficult to diagnose, and diagnostic criteria are mainly clinical. In search of novel candidate biomarkers in BS, we determined the miRNome in plasma samples from BS patients in comparison with healthy controls (HC), obtaining a profile of deregulated (DE) circulating microRNAs (ci-miRNAs). Methods: The ci-miRNA profile was evaluated by microarray technology in plasma samples of 34 subjects (16 BS patients and 18 HC). Results were validated by RT-qPCR in a larger and independent cohort composed of 60 subjects (30 BS patients and 30 HC). Functional annotation analysis (FAA) was used to define the potential biological meaning of altered ci-miRNAs expression in BS. Results: 36 ci-miRNAs turned out to be DE in BS, 19 up- and 17 down-regulated from microarray screening. Microarray clustering analysis of both the comprehensive and selected top DE ci-miRNAs segregated BS patients and HC, independently from patients’ clinical or demographic features. FAA showed that DE ci-miRNAs identified by microarray potentially modulate genes related to immune-inflammatory pathways, as expected. Noteworthy, the most enriched pathways affected by selected DE ci-miRNAs belonged to three main processes (cell-matrix interaction, oxidative stress and blood coagulation) related to thrombo-inflammation, uniquely associated with BS. RT-qPCR validation of the top selected DE ci-miRNAs confirmed the deregulation of miR-224-5p, miR-206 and miR-653-5p in a larger and independent validation cohort. A promising diagnostic accuracy emerged from ROC curve analysis of the combination of these 3 cimiRNAs, as well as the association of this signature with important BS patients’ clinical features. Conclusion: The DE ci-miRNA profile we identified in BS may represent a source for novel non-invasive candidate biomarkers. Overall, such profile is suggestive of the deregulation of pathways related to the thrombotic balance, hence highlighting that the thrombo-inflammatory features of BS are potentially under epigenetic surveillance. The validated plasmatic ci-miRNAs combination shows promising diagnostic potential and overall association with BS manifestations. More investigations are needed within a larger sample size to further validate the diagnostic value of the reported ci-miRNAs.