Aggressive Periodontitis

The goal of this observational study is to investigate cellular heterogeneity and inflammatory microenvironment features in gingival tissues from patients with aggressive periodontitis compared to chronic periodontitis and healthy controls, using single-cell and spatial transcriptomics combined with whole-genome sequencing. The main question(s) it aims to answer are: What are the differences in cellular composition, mesenchymal stem cell subpopulations, and gene expression profiles between aggressive periodontitis, chronic periodontitis, and healthy gingival tissues? Which key molecular markers, signaling pathways, and spatially resolved microenvironment patterns distinguish aggressive periodontitis from the more common chronic form? Are there disease-specific genetic variants associated with aggressive periodontitis identified through whole-genome sequencing of peripheral blood DNA? Participants (already scheduled for tooth extraction or periodontal surgery as part of routine clinical care) will undergo: Standard clinical periodontal examination and CBCT imaging Collection of a small gingival tissue sample (\~1×3×1 mm) during the planned extraction/surgery under local anesthesia Collection of 5 mL peripheral blood for DNA extraction No additional intervention, treatment, or follow-up visit is required beyond routine dental care. Last updated: December 23, 2025

The inflammatory response involves many players from the immune response, including B lymphocytes. These cells are responsible for the synthesis of immunoglobulins in response to the presence of an antigen. They are characteristic of chronic inflammation. There are several subsets of B cells characterized by specific membrane markers. Once activated, these cells express many factors contributing to tissue destruction seen in periodontitis and particularly in osteoclastogenesis (receptor activator of nuclear factor kappa-B ligand, tumor necrosis factor, interleukin-6, macrophage inflammatory protein-1α and Monocyte Chemoattractant Protein-3). During the establishment of a periodontal disease, an important inflammatory infiltrate is observed in the gum. This infiltrate is characterized by the presence of many B lymphocytes. B cell subsets in the blood and the gum of patients with periodontitis have been little studied. However, the number of autoreactive B cells (cluster of differentiation (CD)19+, CD5+) has been reported to be higher in the blood of patients with periodontal disease. In the gum, the rate of B and T cells increases with the level of inflammation and is correlated with the severity of the inflammatory process. Activation of B cells is a prerequisite for the progression of gingivitis to periodontitis. B cell distribution could then be an indicator of disease progression, but also allow to study the response to treatment. The aim of this pilot study is to characterize B cell subsets in the blood and the gum of patients with periodontitis, according to disease activity. Analysis of B cells in the blood could highlight the association of a particular subpopulation with aggressive periodontal disease and evidence a particular biological profile of the host response. The investigators also wish to observe the evolution of this phenotype following an unconventional surgical therapy. This study would better understand the pathogenesis of periodontal disease and refine the diagnosis, prognosis and treatment of periodontitis, and thus participate in the development of personalized medicine. Biological monitoring of therapeutic effects may be initiated and allow more effectively prevent recurrence.