Vitamin D and miRNA-155 in Behçet's Disease: Possible Association with the Disease and Disease Activity.

Background: Vitamin D (vit D) controls inflammation and immunity. In Behçet's disease (BD), microRNA-155 is recognized as a significant immune response regulator. We aimed to investigate the role of vit D on immunomodulation and downregulation of inflammatory pathways associated with BD and detect the role of miRNA-155 in BD.

Methods: miRNA-155 expression by Real Time -Polymerase Chain Reaction (RT-PCR), and vit D, nuclear factor Kappa-light-chain-enhancer of activated B cells (NF-κB), and Tumor necrosis fact of TNF-α) expression by Enzyme Linked Immunosorbent Assay (ELISA) were assessed.

Results: BD patients had a significantly higher relative expression of microRNA-155 (P< 0.001), it was significantly related to vascular manifestations (P< 0.001). Vit D relative expression was significantly low in BD (P< 0.001). There was a significant rise in miRNA-155 in the active group compared to the inactive group (P< 0.001). A significant decrease in vit D levels (IU) was found in inactive and active individuals suffering from BD when compared to controls (P< 0.001). A significant rise was found in vit D levels in inactive BD cases (P< 0.001). A significant positive correlations were found between miRNA-155, NF-κB, TNF-α, and negative correlations with vit D relative expression in BD patients.

Conclusions: miRNA-155 relative expression is higher in BD is significantly related to vascular manifestations. It may have a relationship to disease activity. Vitamin D relative expression is significantly low in BD patients, which can significantly influence immunomodulatory BD therapy. Vitamin D deficiency linked to active BD.