CD4+CD25+ T regulatory cells and MMP-9 as diagnostic salivary biomarkers in oral lichen planus.

Oral lichen planus (OLP) is a chronic inflammatory disease characterized by a dense subepithelial lymphocytic infiltrate, degeneration of basal keratinocytes and basement membrane disruption. Non-specific mechanisms include mast cell degranulation and matrix metalloproteinase (MMP) activation in OLP lesions. These mechanisms may combine to cause T-cell accumulation in the superficial lamina propria, basement membrane disruption, intra-epithelial T-cell migration, and keratinocyte apoptosis in OLP. Obviously, abnormality of immunological regulation may contribute to its pathogenesis. This study aimed at evaluating the role of salivary CD4+CD25+ T regulatory cells & Matrix Metalloproteinase-9 (MMP.9) as salivary biomarkers in patients with OLP. Twenty patients with various forms of OLP were investigated: 8 with bullous erosive form, 7 with atrophic and 5 with reticular forms. From each patient saliva was collected, and used for assessment of salivary T regulatory cells by immunoflourescent and MMP9 expression by quantitative RT-PCR. Nine out of the twenty patients showed CD4+CD25+ Tregs in saliva by immunoflourescent staining with sensitivity (90%), specificity (83.3%) and diagnostic accuracy (87.5%). molecular detection of salivary MMP-9 levels in CD4+CD25+ Tregs +ve cases showed a significant increase in CD4+CD25+ Tregs +ve cases. In conclusion, salivary CD4+CD25+ T regs and MMP-9 could be considered as sensitive and specific diagnostic & prognostic biomarkers in the detection of OLP.