重症肺炎儿童支气管肺泡灌洗液中的树突状细胞变化

目的通过研究重症肺炎患儿支气管肺泡灌洗液(BALF)中成熟树突状细胞(DC)的数量与白介素12(IL12)以及临床评分的关系,了解DC在重症肺炎发生、发展中的作用。方法2002年11月～2003年5月我院重症监护病房收治的重症肺炎患儿27例为重症肺炎组,同期呼吸组收治的普通肺炎患儿30例作为普通肺炎组,选取同期在本院胸外科收治的胸部手术患儿29例,作为对照组。重症肺炎组和对照组在插管第1天和第2天取BALF测定成熟DC,并对重症肺炎组和普通肺炎组进行肺部炎症程度的临床评估,三组患儿在入院第1天采血,用ELISA方法检测IL12。结果插管当天和插管第2天重症肺炎组BALF中成熟DC百分率高于对照组,两组有显著差别(P均<0.01);重症肺炎组中插管当天成熟DC百分率略高于插管第2天,但无统计学意义(P=0.05);插管当天成熟DC百分率与急性肺损伤评分呈正相关(r=0.37,P<0.05),与儿童危重评分无显著相关性(r=-0.11,P>0.05)。重症肺炎组中IL12浓度高于普通肺炎组(P<0.01),和对照组比较(P<0.01),有统计学意义;普通肺炎组中IL12浓度显著高于对照组(P<0.01),有统计学意义;插管当天成熟DC百分率与IL12呈正相关(r=0.48,P<0.01)。结论儿童重症肺炎中肺部DC的过度成熟、活化与病情严重程度相关,并伴随着IL12水平的升高,这表明其从启动环节上影

Changes of dendritic cells in BALF of severe pneumonia in children

Objective To study the role of dendritic cells (DC) in the development of severe pneumonia in children,we measured the number of mature DC in bronchoalveolar lavage fluid (BALF),and evaluated the relationship among IL-12 and clinical scores.Methods From November 2002 to May 2003,27 children with severe pneumonia in PICU from children's hospital of Fudan University were included.Thirty children with common pneumonia and 29 children without pneumonia but receiving ventilator for chest surgery were recruited as normal control group.Mature DC in BALF was evaluated in severe pneumonia group and the control group d1 and d2 after ventilation.Clinical and physiological data were obtained from children in the severe pneumonia and common pneumonia group.Serum levels of IL-12 were measured by ELISA in all children 24 hours after admission.Results The percent of mature DC in children with severe pneumonia was significantly higher compared with the control group on the d1 and d2 after ventilation(P<0.01 in both groups).The percent of mature DC on the first day after ventilation was correlated to lung injury score(r=0.37,P<0.05),but it had no relationship with child severe scores(r=-0.11,P>0.05).The concentration of serum IL-12 was significantly higher in the severe pneumonia group than in the common pneumonia group and normal control group.Serum IL-12 level in children with common pneumonia was higher than in the common(P<0.01)and control groups(P<0.01).The percent of mature DC on the first day was positively correlated with the serum level of IL-12(r=0.48,P<0.01).Conclusion Over-stimulation of lung dendritic cells may reflect the degree of lung inflammatory response.It plays a central role in the pathogenesis of severe pneumonia in children.With over-stimulation of lung DC,the serum level of IL-12 increased.The activation of DC may influence the serum level of cytokine from initial step which resulting in the development of severe pneumonia.