血清特异性抗体检测在儿童急性下呼吸道人博卡病毒感染诊断中的应用

Serodiagnosis of human bocavirus lower respiratory tract infection in children

目的 探讨血清特异性抗体检测在儿童急性下呼吸道人博卡病毒（HBoV）感染诊断中的应用价值.方法 选择2013年1至4月苏州儿童医院呼吸科收治的714例急性下呼吸道感染（ALRI）患儿为研究对象,采集患儿血清、痰液及肺泡灌洗液（BALF）,用ELISA法检测血清中HBoV特异性IgG、IgM抗体,实时荧光定量PCR法检测血清、痰液及BALF中HBoV DNA.以血清和（或）BALF HBoV DNA检测结果为评价标准,将血清HBoV抗体、痰液HBoV DNA及血清HBoV抗体＋痰液HBoV DNA的检测结果分别与评价标准比较,评价其一致性及优劣性,并计算3项检测结果灵敏度、特异度、阳性预测值、阴性预测值、符合率、Kappa值、J指数等各项诊断评价指标.分析血清HBoV抗体＋痰液HBoV DNA与血清和（或）BALF HBoV DNA在各年龄组的检出情况.结果 （1）714例患儿血清HBoV抗体检出率13.2％ （94/714）、痰液HBoV DNA检出率14.3％ （102/714）、血清HBoV抗体＋痰液HBoV DNA一致检出率8.1％（50/618）与评价标准（检出率6.7％）对照均具有高度一致性（x2 =91.834、124.662、138.643,P均＜0.001）;3项方法的检出率均优于评价标准（x2=23.547、33.440、12.410,P均＜0.001）.（2）3项检测结果的灵敏度、特异度、阳性预测值、阴性预测值、符合率、J指数分别为：血清HBoV抗体：58.3％、90.1％、29.8％、96.8％、88.0％、0.484（Kappa=0.335,P＜0.001）;痰液HBoV DNA：68.8％、89.6％、32.4％、97.5％、88.2％、0.584 （Kappa=0.384,P＜0.001）;血清HBoV抗体＋痰液HBoV DNA：70.4％、94.8％、38.0％、98.6％、93.7％、0.652（Kappa=0.463,P＜0.001）.（3）血清HBoV抗体＋痰液HBoV DNA与血清和（或）BALF DNA的检测结果均提示,3岁以下患儿的HBoV检出率较高,尤以～1岁组最高,且同一年龄组两项检测的HBoV检出率差异均无统计学意义（P均＞0.05）.但两项检测在各年龄组的检出率差异均有统计学意义（x2=58.303、35.053,P均＜0.01）,两者均以～1岁组最高,其次为～3岁组,前者＞3岁组最低,后者～6个月组最低.结论 作为血清学依据的HBoV抗体检测与传统的痰液HBoV DNA检测结合,可以有效提高儿童急性下呼吸道HBoV感染的诊断效力,并反映HBoV感染的年龄分布情况.

Objective To study the application of serodiagnosis of human bocavirus （HBoV） lower respiratory tract infection in children.Method From January to April,2013,samples including serum,sputum and bronchoalveolar lavage fluids （BALFs） were obtained from 714 children hospitalized with ALRI.Serums were tested for HBoV-specific IgG and IgM antibodies by ELISA and all kinds of samples were tested for HBoV DNA by quantitative real-time fluorescent PCR.The results of HBoV serologic tests,viral DNA in sputum and their combination were compared with those of HBoV DNA in serums and/or BALFs,which was considered as the ＂standard＂.Their consistence and differences were evaluated,and the diagnostic parameters including sensitivity,specificity,positive predictive value,negative predictive value,consistency rate,Kappa value and J value were calculated.Age distributions of the HBoV positive patients tested by the latter two methods were also compared.Result The positive rate of HBoV serology was 13.2％ （94/714）.The results of HBoV serology,its DNA in sputum and their combination were all consistent with those of HBoV DNA in serums and/or BALFs（x2 =91.834,124.662,138.643,P ＜ 0.001 for all comparisons）.Differences were significant by McNemar test（x2 =23.547,33.440,12.410,P all ＜ 0.001）.All the diagnostic parameters for single HBoV serologic test or single viral DNA test in sputa were approximate.However,they were improved to 70.4％,94.8％,38.0％,98.6％,93.7％,0.463 （P ＜ 0.001）,0.65 for sensitivity,specificity,positive predictive value,negative predictive value,consistency rate,Kappa value and J value,respectively,when the methods were combined.HBoV was found positive mainly in children under 3 years of age,especially in the 1 year group.The positive rates were the highest in both group-1 year,and group-3 years was the next.However,the rate was the lowest in group ＞3 years and in the group-6 months.Conclusion Diagnostic power can be improved and age distribution can be demonstrated when serologic tests were combined with traditional sputum DNA detection in children with HBoV lower respiratory tract infection.