Local and General Inflammatory Mediators Status in Patients with Oral Lichen Planus

Background: Oral Lichen Planus (OLP) is a chronic inflammatory, autoimmune disorder affecting the skin and mucosa classified within the broad group of Oral Potentially Malignant Disorders (OPMDs). Topical treatment is usually effective in resolving the oral inflammation associated with the process, and the possible relationship to a systemic immunological reaction has not been widely discussed. The aim of this study was to explore the relationship between local and systemic inflammatory signatures in OLP by identifying potential markers in salivary and serum samples, as well as the topical treatment used to relieve inflammation. Methods: The study design was a cross-sectional case-control hospital-based study. A total of 50 blood samples, comprising 31 patients with OLP (study group) and 19 individuals without OLP status (control group), were tested for HLA-B27 in this study. Salivary and serum levels of Prostaglandin E2 (PGE2), matrix metalloprotease 8 (MMP-8), and human IL-1 beta (IL-1β) were measured within and between the control and OLP groups. Results: Salivary IL-1β levels were significantly higher in the OLP group than in controls (p = 0.001; W = 101.5). Serum MMP-8 concentrations were significantly lower in patients with OLP. Serum PGE2 levels were elevated in the OLP group; however, the difference was only borderline statistically significant after correction. HLA-B27 allele frequency in the study and control groups was compared with that in the Polish population. Using Fisher's Exact Test for Count Data, p-value = 0.1404, no statistically significant differences were found between the control and study groups. Conclusions: These findings could suggest that inflammatory activity in OLP might be predominantly localized to the oral cavity rather than systemic. Elevated salivary IL-1β and reduced systemic MMP-8 levels could support the concept of local immune dysregulation; moreover, salivary IL-1β may serve as a potential non-invasive biomarker for the diagnosis and monitoring of OLP. Studies involving a larger number of subjects should be conducted to strengthen the provided conclusion.