幽门螺杆菌感染及根除后胃黏膜CD4＋CD25＋调节性T细胞表达的变化

目的观察幽门螺杆菌（helicobacter pylori，Hp）感染及根除后CD4＋CD25＋调节性T细胞的表达变化，以探讨Hp长期定植在胃黏膜引起慢性持续性感染的原因。方法采用免疫组化法分析45例Hp阳性患者（研究组）Hp清除前后及35例Hp阴性患者（对照组）胃黏膜中的CD4＋CD25＋调节性T细胞的表达变化。结果Hp阳性患者局部胃黏膜中的CD4＋CD25＋调节性T细胞明显增多，占5．012％，明显高于Hp阴性患者胃黏膜中的CD4＋CD25＋调节性T细胞，占0．739％，差异有统计学意义（P〈0．01）.根除Hp治疗后CD4＋CD25＋调节性T细胞明显减少，占0．551％，明显低于清除前，差异有统计学意义（P〈0．01o结论Hp感染后可能通过上调CD4＋CD25＋调节性T细胞的表达，抑制Hp引起的特异性T细胞反应，造成Hp的长期定植。根除Hp后人胃黏膜内CD4＋CD25＋调节性T细胞明显减少可能是Hp被清除后，该类细胞凋亡或者移出胃黏膜所致。

Expression of CD4+CD25+ regulatory T Cells in gastric mucosa of patients with Helicobacter pylori infection before and after eradication

Objective To investigate the expression of CD4＋CD25＋ regulatory T cells in patients with Helicobacter pylori （H. pylori） infection before and after eradication. Methods Biopsies of gastric mucosa were performed in 45 H. pylori-positive patients （test group） before and after H. pylori eradication and 35 H.pylod-negative adults （control group）. Immunohistochemical staining was used to semi-quantify the number of CD4＋CD25＋T cells in gastric mucosa. Results The ratio of CD25＋ T cell in CD4＋ T cells accounted for 0.739% in H. pylori-negative individuals, while it was 5.012% in H. pylori-positive patients （P〈0.01）. After eradication of H. pylori the ratio of CD25＋ T cell in CD4＋ T cells declined to 0.551% （P〈0.01）. Conclusion The results indicate that H. pylori infection may up-regulate CD4＋CD25＋ regulatory T cells, suppressing the expression of H.pylori-specific T cell response and resulting in long-term H.pylori colonization.