NETS BIOMARKERS IN SALIVA AS A POTENTIAL PROGNOSTIC AND THERAPEUTIC TARGET IN PATIENTS WITH ORAL LICHEN PLANUS

Abstract

Objective: To assess changes in the levels of neutrophil extracellular traps (NETs) and cellular elements in saliva among patients undergoing treatment for erosive and ulcerative oral lichen planus (LP). Methods: Two groups were established for the study: a control group consisting of 12 participants and a group of 12 patients with oral LP. The research involved analyzing saliva samples before treatment (referred to as "LP before treatment") and immediately after treatment (referred to as "LP after treatment"). The saliva samples were stained with propidium iodide and FITC antibodies to CD45 and examined using fluorescence microscopy. The analysis focused on determining the percentage of various cell types, including NETs in the form of "cloud" and "threads," early NETosis cells, leukocytes, single epithelial cells, and clusters of epithelial cells in healthy volunteers (control group), and in patients with LP before and after treatment. Results: All patients diagnosed with LP experienced a significant improvement during the treatment period. This improvement was subjectively characterized by a reduction in pain and objectively by the healing of oral sores, improved oral hygiene, bleeding, and inflammation indices. It was observed that saliva neutrophils in all study groups predominantly formed filiform NETs. Notably, patients in the "LP before treatment" group had a statistically significantly higher percentage (p<0.001) of filiform NETs (17.1% [13.1; 25.5]) compared to the control group (2.2% [1.2; 3.1]), indicating a distinct difference in neutrophil behavior. After treatment, the proportion of filiform NETs in the saliva of patients with LP statistically significantly decreased (p=0.005) but did not reach the values of the control group. Cloud-shaped NETs were not detected in the saliva preparation under normal conditions; however, in LP, neutrophils actively formed cloud-shaped NETs. Conclusion: Elevated levels of NETs and early NET cells in the saliva of patients with LP could serve as valuable and sensitive indicators for evaluating the resolution of the inflammatory process and the maintenance of remission. On the other hand, the excessive formation of NETs during LP may contribute to damage to the oral mucosa, suggesting that targeting NETs could be a promising approach for improving treatment outcomes.

Keywords

• lichen planus
• oral mucosa
• neutrophil extracellular traps
• netosis
• saliva.