CD4 and periodontitis: In terms of median fluorescence intensity, chronic periodontitis resulted in a decrease in CD39 on CD39 + activated CD4 regulatory T cell (Beta = -0.12 [-0.10, -0.13], P = 0.04), CD39 on CD39 + secreting CD4 regulatory T cell (Beta = -0.16 [-0.14, -0.18], P = 0.01), CD39 on CD39 + CD4 + T cell (Beta = -0.13 [-0.12, -0.15], P = 0.02), CD11b on basophil (Beta = -0.17 [-0.14, -0.19], P = 0.04), HLA DR on HLA DR + T cell (Beta = -0.15 [-0.13, -0.17], P = 0.03).