目的：探讨全身炎症反应综合征（SIRS）患儿血液中性粒细胞、淋巴细胞CD11b表达对诊断和判断病情的意义。方法：用流式细胞术检测36例SIRS患儿血液中性粒细胞、淋巴细胞CD11b表达水平，28例一般感染性疾病，不符合SIRS诊断标准的患儿作为对照组。比较各指标对诊断SIRS的灵敏度、特异度，评价它们对诊断SIRS和判断病情的价值。结果：急性期SIRS组中性粒细胞CD11b表达为（96.7±8.1）%，高于对照组的（85.1±5.1）%，差异有显著性（P＜0.05）。中性粒细胞CD11b＞92.24%为阳性标准，诊断SIRS敏感性和特异性分别为97.2%，92.9%。急性期SIRS组淋巴细胞CD11b表达为(13.4±8.6)%，对照组为（19.2±6.4）%，差异有显著性（P＜0.05）；其中严重脓毒症组淋巴细胞CD11b表达为（7.3±3.0）%，低于非感染SIRS组的（19.3±2.9）%和脓毒症组的(15.9±12.5)%（P＜0.01）。恢复期SIRS组淋巴细胞CD11b表达为（13.35±4.89）%，对照组为（13.8±4.7）%，差异无显著性（P＞0.05）。结论：中性粒细胞CD11b可作为诊断SIRS的可靠指标，淋巴细胞CD11b表达下调可能是SIRS患儿病情加重的信号。［中国当代儿科杂志，2009，11（7）：540-542］

OBJECTIVE: To investigate the significance of CD11b expression in neutrophils and lymphocytes in children with systemic inflammatory response syndrome (SIRS). METHODS: CD11b expression in neutrophils and lymphocytes was measured using flow cytometry in 36 children with SIRS (SIRS group) and 28 children with infectious disease but without SIRS (control group). The sensitivity and specificity of neutrophil CD11b for diagnosis of SIRS were evaluated. RESULTS: During the acute phase, an increased CD11b expression in neutrophils (96.7±8.1%) was observed in the SIRS group compared with the control group (85.1±5.1%) (P<0.05). Using neutrophil CD11b expression >92.2% as a cut-off value for diagnosis of SIRS, the sensitivity and the specificity were 97.2 % and 92.9% respectively. Lymphocytic CD11b expression in the SIRS group (13.4±8.6%) was lower than that in the control group (19.2±6.4%) in the acute phase (P<0.05). In the SIRS group, lymphocytic CD11b expression was remarkably suppressed in the severe sepsis subgroup (7.27±3.04%), showing significantly decreased expression compared with the non-infectious subgroup (19.3±2.9%) and the sepsis subgroup (15.9±12.5%) (P<0.01). In the convalescence stage lymphocytic CD11b expression in the SIRS group was similar to that in the control group. CONCLUSIONS: CD11b expression in neutrophils may serve as a reliable indicator for diagnosis of SIRS. The down-regulation of lymphocytic CD11b expression might be a signal of the condition aggravation in children with SIRS.［Chin J Contemp Pediatr, 2009, 11 (7):540-542］