Effects of cold physical plasma on oral lichen planus: An in vitro study (Effects of CAP on OLP)

Objectives In the search for more effective and safe treatment avenues, we investigated cold physical plasma as a new treatment modality for therapy of oral lichen planus (OLP). Material and Methods Healthy and diseased human mucosal tissue samples with a size of 3 mm in diameter obtained from OLP patients were subjected to plasma treatment ex vivo or were left untreated. Tissue sections were quantified for immune-infiltration of CD4(+), CD8(+), CD45RA(+), and CD45R0(+) T cells. Moreover, the tissues' inflammatory profile was assessed by analyzing 12 different cytokines in the surrounding media. Results A significantly increased infiltrate of CD8(+) and CD45-R0(+) T cells was detected in OLP tissue samples when compared to healthy tissue. A higher concentration of interleukin (IL) 1 beta, IL6, IL8, and granulocyte macrophage-colony stimulating factor (GM-CMF) was detected in OLP samples compared to healthy mucosal tissue. For all cytokines and chemokines investigated, 23 out of 24 comparisons showed a decrease in tendency (significant for IL1 beta, IL2, IL10, and GM-CSF) in response to plasma treatment. In ex vivo-treated tissue, a decrease of T-cell infiltrate in OLP lesions compared with healthy tissue was observed. Conclusion Our findings suggest cold physical plasma can be a promising therapeutic option for OLP that requires further validation in vivo.