病原学筛查及C-反应蛋白、降钙素原和白细胞介素-6在小儿下呼吸道感染诊断及疗效监测中的应用

Diagnosis value and efficacy monitoring of pathogenic screening and detection of C-reactive protein,proalcitonin and interleukin-6 in pediatric lower respiratory tract infection

目的探讨病原学筛查以及C-反应蛋白(CRP)、降钙素原(PCT)和白细胞介素-6(IL-6)检测在小儿下呼吸道感染诊断及疗效监测中的应用价值。方法选取成都医学院第二附属医院·核工业四一六医院2016年12月至2019年6月收治的下呼吸道感染患儿共223例,根据患儿所感染病原体类型分为细菌感染组(64例)、病毒感染组(48例)、支原体感染组(51例)和混合感染组(60例)。入院后于患儿鼻孔中插入无菌吸痰管取下呼吸道分泌物进行细菌学检测,各组患儿入院后第2天空腹抽取血液样本进行病毒学及IL-6、PCT和CRP水平检测。采用配对t检验和LSD-t检验分析各组患儿病原学,血清IL-6、CRP和PCT水平;并采用受试者工作特征曲线(ROC)曲线分析IL-6、CRP和PCT对下呼吸道细菌感染、革兰阴性菌感染的诊断效能。结果细菌感染组64例患儿中革兰阳性菌感染者29例(45.31%)、革兰阴性菌感染者35例(54.69%);病毒感染组48例患儿中致病病毒包括腺病毒(10例、20.83%)、呼吸道合胞病毒(15例、31.25%)、甲型流感病毒(6例、12.50%)、乙型流感病毒(12例、25.00%)和副流感病毒(5例、10.42%);混合感染组60例患儿中革兰阳性细菌感染15例(25.00%)、革兰阴性菌感染8例(13.33%),病毒感染13例(21.67%),支原体感染24例(40.00%)。治疗前细菌感染组、病毒感染组、支原体感染组、混合感染组患儿血清IL-6、CRP和PCT水平差异有统计学意义(F=47.286、93.648、83.277,P均<0.001),治疗后各组患儿血清IL-6、CRP和PCT水平均较治疗前降低(t_(IL)-6=13.864、15.396、12.378、8.926,t_(CRP)=29.262、11.483、14.869、21.654,t_(PCT)=33.735、9.593、11.276、33.414,P均<0.001),且治疗后各组患儿IL-6、CRP和PCT水平差异亦有统计学意义(F=38.365、50.072、29.479,P均<0.001)。革兰阳性菌感染患儿血清IL-6、CRP和PCT水平低于革兰阴性菌感染者(t=2.598、P=0.012,t=2.593、P=0.012,t=2.791,P=0.007)。三指标联合诊断对下呼吸道感染敏感度(93.75%)、特异度(93.94%)和准确度(93.87%)、阴性预测值(93.10%)、阳性预测值(94.29%)高于IL-6(68.57%、58.62%、64.06%、60.71%、66.67%)、CRP(62.86%、62.07%、62.50%、58.06%、66.67%)和PCT(71.43%、68.97%、70.31%、66.67%、73.53%)单独诊断(χ^(2)=10.470、10.152、20.213、36.559、27.559,P=0.015、0.017、0.001、0.001、0.001);联合诊断对下呼吸道感染诊断效能ROC曲线下面积(AUC)与IL-6、CRP、PCT单指标诊断差异均有统计学意义(Z=21.350、18.769、9.341,P<0.001、<0.001、=0.002)。三指标联合诊断革兰阴性菌感染敏感度(94.29%)、特异度(93.10%)、准确度(93.75%)、阴性预测值(93.10%)、阳性预测值(94.29%)高于IL-6(68.57%、58.62%、64.06%、60.71%、66.67%)、CRP(62.86%、62.07%、62.50%、58.06%、66.67%)和PCT(71.43%、68.97%、70.31%、66.67%、73.53%)单独诊断(χ^(2)=10.470、10.152、20.213、36.559、27.559,P=0.015、0.017、0.001、0.001、0.001);联合诊断对革兰阴性菌感染诊断效能ROC曲线AUC与IL-6、CRP、PCT单指标诊断差异均有统计学意义(Z=56.446、37.966、20.746,P均<0.001)。结论小儿下呼吸道感染病原体种类较多,其中革兰阴性菌所占比最高,可通过联合测定IL-6、CRP和PCT水平进行诊断及病原学筛查,且可通过动态监测上述指标评估疗效,并制定和调整治疗方案。

Objective To investigate the value and application of pathogenic screening and C-reactive protein(CRP),procalcitonin(PCT)and interleukin-6(IL-6)detection in diagnosis and efficacy monitoring of children with lower respiratory tract infection.Methods Total of 223 children with lower respiratory tract infection admitted at The Second Affiliated Hospital of Chengdu Medical College,The 416 Hospital of Nuclear Industry from December 2016 to June 2019,were selected and divided into bacterial infection group(64 cases),viral infection group(48 cases),mycoplasma infection group(51 cases)and mixed infection group(60 cases)according to different pathogen type.After admission,a sterile suction tube was inserted into the nostrils of child to remove the respiratory tract secretions for bacteriological examination.Blood samples of children in three groups were taken on the 2nd day after admission for virological examination and IL-6,PCT and CRP detection.Pathogen distribution,serum levels of IL-6,CRP and PCT of children in each group were analyzed by paired t test and LSD-t test;the diagnostic efficacy of IL-6,CRP and PCT on bacterial infection of the lower respiratory tract,and Gram-negative bacteria were analyzed by receiver operating characteristic curve(ROC).Results Among the 64 children in bacterial infection group,29 cases(45.31%)were with Gram-positive bacteria infection and 35 cases(54.69%)with Gram-negative bacteria infection;among the 48 children in viral infection group,the causative viruses included adenovirus(10 cases,20.83%),respiratory syncytial virus(15 cases,31.25%),influenza A virus(6 cases,12.50%),influenza B virus(12 cases,25.00%),parainfluenza virus(50 cases,10.42%).Among the 60 children in mixed infection group,15 cases(25.00%)were with Gram-positive bacteria infection,8 cases(13.33%)with Gram-negative bacteria infection,13 cases(21.67%)with viruses infection,and 24 cases(40.00%)with mycoplasma infection.The levels of serum IL-6,CRP and PCT levels of children in bacterial infection group,viral infection group,mycoplasma infection group and mixed infection group before treatment were significantly different(F=47.286,93.648,83.277;all P<0.001),and serum IL-6,CRP,and PCT levels decreased in the four groups after treatment compared with those of before treatment(t_(IL)-6=13.864,15.396,12.378,8.926;t_(CRP)=29.262,11.483,14.869,21.654,t_(PCT)=33.735,9.593,11.276,33.414;all P<0.001),and levels of IL-6,CRP and PCT were significantly different among the four groups after treatment(F=38.365,50.072,29.479,all P<0.001).The levels of serum IL-6,CRP,and PCT were significantly lower of cases with Gram-positive bacteria infection than those with Gram-negative bacteria infection(t=2.598,P=0.012;t=2.593,P=0.012;t=2.791,P=0.007).The combined diagnosis had higher sensitivity(93.75%),specificity(93.94%)and accuracy(93.87%),negative predictive value(93.10%)and positive predictive value(94.29%)for lower respiratory tract infection than IL-6(68.57%,58.62%,64.06%,60.71%,66.67%),CRP(62.86%,62.07%,62.50%,58.06%,66.67%)and PCT(71.43%,68.97%,70.31%,66.67%,73.53%)alone(χ^(2)=10.470,10.152,20.213,36.559,27.559,P=0.015,0.017,0.001,0.001,0.001);The area under the ROC curve(AUC)of three indexes combined diagnosis of lower respiratory tract infection were significantly different compared with IL-6,CRP,PCT single index(Z=21.350,18.769,9.341;P<0.001,<0.001,=0.002).The combined diagnosis had higher sensitivity(94.29%),specificity(93.10%),accuracy(93.75%),negative predictive value(93.10%)and positive predictive value(94.29%)for Gram-negative bacteria than IL-6(68.57%,58.62%,64.06%,60.71%,66.67%),CRP(62.86%,62.07%,62.50%,58.06%,66.67%)and PCT(71.43%,68.97%,70.31%,66.67%,73.53%)diagnosed alone(χ^(2)=10.470,10.152,20.213,36.559,27.559,P=0.015,0.017,0.001,0.001,0.001);The area under the ROC curve(AUC)of three indexes combined diagnosis of Gram-negative bacteria infection were significantly different compared with IL-6,CRP,PCT single index(Z=56.446,37.966,20.746;all P<0.001).Conclusions There were many types of pathogens in children’s lower respiratory tract infection,among which,Gram-negative bacteria accounted for the highest proportion.Clinical diagnosis and etiological screening could be carried out by combined determination of levels of IL-6,CRP and PCT.Dynamic monitoring of the above indicators could evaluate the treatment of the disease,and accordingly formulate and adjust the treatment regimen.