Figure 2. Relationship between percentages of CD4⁺CD25⁺ cells (A,B) or CD4⁺CTLA-4⁺ cells (C,D) and B/T ratio, and CD4⁺CD25⁺ and CD4⁺CTLA-4⁺ cells (E,F). Fifty areas of 17 specimens of periodontitis and 15 areas of 9 specimens of gingivitis were analyzed. Each circle represents one area. Significantly positive correlation was observed between the percentages of double-positive cells and the B/T ratio in periodontitis (A,C). Significantly positive correlation was observed between the percentages of CD4⁺CD25⁺ cells and CD4⁺CTLA-4⁺ cells in both periodontitis and gingivitis (E,F). A,C,E: Periodontitis. B,D,F: Gingivitis.