肠道淋巴细胞归巢受体在胃肠功能障碍的危重症患儿外周血中表达的变化

Expression of lymphocyte homing receptor in peripheral blood of the critically ill children with gastrointestinal dysfunction

目的探讨危重症患儿胃肠功能障碍时外周血肠道淋巴细胞归巢受体（整合素α4β7和L-选择素）的表达及其与肠道黏膜免疫功能的关系。方法4个月～14岁危重症患儿45例。分为胃肠功能衰竭组及非胃肠功能衰竭组，选择25例健康体检儿为对照组。用流式细胞仪检测整合素α4β7和L-选择索的表达。结果胃肠功能衰竭组外周血中整合素α4β7和L-选择素水平明显减低。胃肠功能衰竭组与非胃肠功能衰竭组比较差异有显著性（P〈0．05），胃肠功能衰竭组与对照组比较差异亦有显著性（P〈0．05）。结论整合素α4β7和L-选择素水平在危重症患儿发生胃肠功能障碍的早期就降低。肠道淋巴细胞归巢受体可能通过抑制淋巴细胞向肠道的归巢，使肠黏膜免疫屏障受损，进而降低肠黏膜的免疫功能。

Objective To investigate lymphocyte homing receptor Integrin α4β7 and L-selectin expression in peripheral blood of critically ill children with gastrointestinal dysfunction and to explore possible mechanisms of immune dysfunction in gastrointestinal tract. Methods Forty-five patients, aged from 4 months to 14 years old, were enrolled and divided into two groups： non-gastrointestinal dysfunction group （20 patients） and gastrointestinal dysfunction group （25 patients）. Twenty-five age-matched healthy children were used as control. The positive percentage of Integrin α4β7 and L-selectin lymphocytes in peripheral blood were measured by flow cytometry. Results The positive percentage of Integrin α4β7 and L-selectin lymphoeytes in peripheral blood in gastrointestinal dysfunction group was significantly lower than those of other groups. There was statistical significance between non-gastrointestinal dysfunction group and gastrointestinal dysfunction group （P 〈 0.05）, as well as between normal control and gastrointestinal dysfunction group（ P 〈 0.05）. Conclusion There were leas positive expression of Integrin α4β7 and L-selectin in peripheral blood lymphocytes at the early stage of gastrointestinal dysfunction group. When lymphocytes were suppressed in homing to intestine, intestinal membrane immune barrier was impaired and intestinal immune dysfunction occurred.