A targeted NanoString analysis of immune gene expression in smokers and non-smokers with severe periodontitis

Objectives : Periodontitis is a chronic inflammatory disease whose severity is strongly influenced by environmental factors, particularly smoking. Smoking is a well-established risk factor for both the onset and progression of periodontitis, contributing to impaired immune responses, delayed healing, and enhanced tissue destruction. In this pilot study, we explored differences in immune-related gene expression between smokers and non-smokers with severe periodontitis. Methods : Gene expression analysis was performed on RNA isolated from saliva samples of six smokers and four non-smokers with severe periodontitis using a targeted NanoString panel comprising 249 immune-related genes. Results : Comparative analysis revealed a distinct expression pattern in smokers, with significantly higher expression of several pro-inflammatory genes, including IL1A , CCL3 , CCL4 , and IL8 . These genes are involved in leukocyte recruitment, chemotaxis, and inflammatory signaling. Conclusion : Although limited by the small sample size, these findings suggest an association between smoking and an enhanced inflammatory gene expression profile in patients with severe periodontitis. The results should be interpreted as exploratory, providing preliminary molecular insights into the way tobacco exposure modulates immune responses in periodontal disease.