血清载脂蛋白E在儿童感染性疾病中的变化

The changes of serum apolipoprotein E in pediatric infectious diseases

目的探讨血清载脂蛋白E（ApoE）在儿童感染性疾病中的变化。方法279例感染性疾病患儿中，脓毒症65例，化脓性脑膜炎47例，细菌性肺炎67例，无菌性脑膜炎47例，支原体肺炎53例。采用透射免疫比浊法（IA）检测感染性疾病患儿的血清ApoE水平。构建B组鼠伤寒沙门菌诱导的脓毒症小鼠模型，采用IA检测小鼠血清ApoE水平，实时荧光定量PCR和Western印迹法检测小鼠肝脏ApoEmRNA和蛋白的表达。两组间均数比较采用独立样本t检验。结果血清ApoE在细菌性感染性疾病患儿中明显升高，在脓毒症患儿中高达（59．8±23．5）mg／L（t=-5．118，P％0．01），在无菌性脑膜炎和支原体肺炎患儿中无明显变化。脓毒症小鼠模型血清ApoE水平明显升高，但肝脏ApoEmRNA和蛋白的表达下降，mRNA的相对值在造模后3h下降了71％（t=5．022，P％0．01），在造模后24h下降了73％（t=4．181，P〈0．01）。结论血清ApoE水平在细菌性感染性疾病中显著升高，而肝脏中ApoE表达下降，说明ApoE血清升高机制与肝脏表达不相关。

Objective To investigate the changes of serum apolipoprotein E （ApoE） in children with infectious diseases. Methods A total of 279 pediatric patients with infectious diseases were enrolled in this study, including 65 patients with sepsis, 47 patients with bacterial meningitis, 67 patients with bacterial pneumonia, 47 patients with aseptic meningitis and 53 patients with mycoplasma pneumonia. The serum ApoE collected from all patients was detected by immunoturbidimetric assay （IA）. The septic mouse model was established by intraperitoneal injection of group B Salmonella typhimurium. Mouse serum ApoE levels were detected by IA, and the hepatic ApoE mRNA and protein expressions of mice were detected by quantitative real-time reverse transcription-polymerase chain reaction （RT-PCR） and Western blot, respectively. Data in two groups were compared by independent-sample t test. Results Serum ApoE levels in patients with bacterial infections were increased dramatically, which was （59.8±23. 5） mg/L in patients with sepsis （t= -5.118, P〈0.01）, while no significant differences were found in patients with aseptic meningitis and mycoplasma pneumonia. Moreover, a high level of serum ApoE was detected in septic mouse model, while the hepatic ApoE mRNA and protein expressions of the mice were both decreased, with mRNA decreased 71% at 3 hour （t=5. 022, P〈0. 01） and 73% at 24 hour （t=4. 181, P〈0. 01）. Conclusions Serum ApoE levels in bacterial infections increase dramatically, while its hepatic expression in septic mouse model is decreased, which indicates that the elevated serum ApoE level is not related to the changes of hepatic ApoE expression.