Peripheral T helper cell profiles during management of periodontitis

Aim Periodontitis has been associated with other systemic diseases with underlying inflammation responsible for the shared link. This study evaluated longitudinal variation in peripheral T helper cells in periodontitis patients undergoing management over 1 year. Materials and methods Periodontal parameters and peripheral blood mononuclear cells (PBMCs) were collected from 54 periodontitis patients at baseline, and 3‐, 6‐ and 12‐months post‐treatment and 40 healthy controls. IFN‐γ+, IL‐4+, IL‐17+ and Foxp3+ and their double‐positive expression were identified in CD4+ and TCRαβ+ cells using flow cytometry. PBMCs were incubated with P. gingivalis, and IFN‐γ, IL‐4, IL‐17 and IL‐10 in cell supernatant were measured by ELISA. Cells and cytokines were also assessed based on clinical response to treatment where good (20%) treatment outcome (TxO) groups had probing depths of ≥5 mm at study conclusion. Results IFN‐γ+ cells were lower at baseline, and 3‐ and 6‐months compared to health, whereas Foxp3+ cells were increased at 12‐months compared to all preceding timepoints and health. The good TxO group showed treatment‐related variation in IFN‐γ+ and Foxp3+ cells, whereas the poor TxO group did not. IFN‐γ and IL‐17 cytokine expression in cell supernatants was significantly lower at baseline compared to health, and IFN‐γ and IL‐10 showed treatment‐related decrease. Conclusion This study suggests that IFN‐γ+ and Foxp3+ cells may have a role in the systemic compartment in periodontitis. Periodontal management has local and systemic effects, and thus, assessment and management of periodontitis should form an integral part of overall systemic health.