Periodontitis and Inflammation : Biological and Clinical Approach of B Cell Role.

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.