Behçet's disease (BD) is a chronic inflammatory autoimmune disorder indicated by relapses. MicroRNAs are small RNA fragments that have the potential to regulate gene expression. Autophagy is a defensive and life-sustaining mechanism that involves the targeting of cytoplasmic components to lysosomes for destruction. MicroRNA-199a-5p and autophagy-related gene 5(ATG5) may have a role in BD. Our goal is to assess the miRNA-199a-5p and ATG5 relative expression in BD patients in order to establish if there is any association between their expression levels and the disease severity.

Real-time PCR was utilized to evaluate the relative expression of miRNA-199a-5p and ATG5 in blood samples collected from 47 individuals with BD and 50 matched healthy controls. Full history taking and examination of BD patients were performed in addition to the severity index of their disease.

There was a highly significant down-regulation of expression of both miRNA-199a-5p and ATG5 in BD individuals than the controls. MiRNA-199a-5p showed a significant decrease in BD patients having thrombophlebitis compared to those who did not have. The relative expression of ATG5 was considerably greater in people with BD who had arterial thrombosis compared to other Behcet sufferers. In BD individuals, there was a strong positive association between miRNA-199a-5p and ATG5 relative expression with r=0.842, and P-value less than 0.001.

We concluded that microRNA 199a-5p and ATG5 may have a role in BD; in BD patients, their relative expression was considerably lower than in controls. MiRNA-199a-5p and ATG5 relative expression was significantly associated with thrombophlebitis and arterial thrombosis, respectively.