【进展】新英格兰最新研究——新生儿吐液PCR检测筛检巨细胞病毒

蓝鱼o_0

Saliva Polymerase-Chain-Reaction Assay for Cytomegalovirus Screening in Newborns

Suresh B. Boppana, M.D., Shannon A. Ross, M.D., M.S.P.H., Masako Shimamura, M.D., April L. Palmer, M.D., Amina Ahmed, M.D., Marian G. Michaels, M.D., Pablo J. Sánchez, M.D., David I. Bernstein, M.D., Robert W. Tolan, Jr., M.D., Zdenek Novak, M.D., Nazma Chowdhury, M.B., B.S., Ph.D., William J. Britt, M.D., and Karen B. Fowler, Dr.P.H. for the National Institute on Deafness and Other Communication Disorders CHIMES Study

N Engl J Med 2011; 364:2111-2118June 2, 2011

Background

Congenital cytomegalovirus (CMV) infection is an important cause of hearing loss, and most infants at risk for CMV-associated hearing loss are not identified early in life because of failure to test for the infection. The standard assay for newborn CMV screening is rapid culture performed on saliva specimens obtained at birth, but this assay cannot be automated. Two alternatives — real-time polymerase-chain-reaction (PCR)–based testing of a liquid-saliva or dried-saliva specimen obtained at birth — have been developed.

先天性巨细胞病毒（CMV）感染是一个听力损失的重要原因，未能早期检测病毒是新生儿巨细胞病毒相关听力损失的重要危险因素。巨细胞病毒的新生儿筛查标准的快速培养法是在出生时就得到唾液标本进行，但此法不能自动化。实时PCR技术为基础的检测新生儿出生后唾液或干燥的唾液样本中CMV的技术已经研发出来。

Methods

In our prospective, multicenter screening study of newborns, we compared real-time PCR assays of liquid-saliva and dried-saliva specimens with rapid culture of saliva specimens obtained at birth.

方法

在前瞻性多中心筛检新生儿研究中，我们比较实时PCR检测新生儿唾液和干燥后的吐液与出生后快速培养唾液标本之间效果的差别。

Results

A total of 177 of 34,989 infants (0.5%; 95% confidence interval [CI], 0.4 to 0.6) were positive for CMV, according to at least one of the three methods. Of 17,662 newborns screened with the use of the liquid-saliva PCR assay, 17,569 were negative for CMV, and the remaining 85 infants (0.5%; 95% CI, 0.4 to 0.6) had positive results on both culture and PCR assay. The sensitivity and specificity of the liquid-saliva PCR assay were 100% (95% CI, 95.8 to 100) and 99.9% (95% CI, 99.9 to 100), respectively, and the positive and negative predictive values were 91.4% (95% CI, 83.8 to 96.2) and 100% (95% CI, 99.9 to 100), respectively. Of 17,327 newborns screened by means of the dried-saliva PCR assay, 74 were positive for CMV, whereas 76 (0.4%; 95% CI, 0.3 to 0.5) were found to be CMV-positive on rapid culture. Sensitivity and specificity of the dried-saliva PCR assay were 97.4% (95% CI, 90.8 to 99.7) and 99.9% (95% CI, 99.9 to 100), respectively. The positive and negative predictive values were 90.2% (95% CI, 81.7 to 95.7) and 99.9% (95% CI, 99.9 to 100), respectively.

本次研究中，共有34989名婴儿，其中177例为巨细胞病毒呈阳性（0.5％，95％可信区间[CI]=0.4~0.6），根据至少有三种方法之一。17662新生儿用Real time-PCR进行检测，17569例呈CMV阴性。运用培养和PCR检测的方法， 85例（0.5％，95％CI=0.4~0.6）显示一致阳性结果。liquid-saliva PCR敏感度和特异度分别为100％（95.8~100）和99.9%（99.9~100）。阳性和阴性预测值分别为91.4％（83.8~96.2）和100％（99.9~100）。按干燥唾液PCR检测方法筛查新生儿17327例，74例巨细胞病毒呈阳性，而76（0.4％，95％CI=0.3~0.5）被发现巨细胞病毒的快速培养阳性。灵敏度和特异性分别为97.4％（95％CI=90.8~99.7）和99.9％（99.9~100）。阳性和阴性预测值分别为90.2％（81.7~95.7）和99.9％（99.9~100）。

Conclusions

Real-time PCR assays of both liquid- and dried-saliva specimens showed high sensitivity and specificity for detecting CMV infection and should be considered potential screening tools for CMV in newborns.

结论

实时PCR检测吐液或者干燥的吐液标本中巨细胞病毒感染有高灵敏度和高特异度，可以考虑作为新生儿CMV筛检的工具。

PS：可以看出，标本形态可以影响检测的灵敏度、特异度、阳性预测值和阴性预测值。在微生物检验中值得重视。这就不难理解，为何采集的标本要尽早进行检验。

toto

回复 1# 蓝鱼o_0


    虽然这个文章对我来说没什么用处，但是学习了

桃子妖妖

应该统一将吐液该为唾液是么？实时PCR技术在实验研究已早为广为应用，弱弱地问下：实时PCR技术在临床上其实用性怎样？

绿茵场

回复 1# 蓝鱼o_0
谢谢 蓝鱼 版主的辛苦工作！

A total of 177 of 34,989 infants (0.5%; 95% confidence interval [CI], 0.4 to 0.6) were positive for CMV, according to at least one of the three methods. Of 17,662 newborns screened with the use of the liquid-saliva PCR assay, 17,569 were negative for CMV, and the remaining 85 infants (0.5%; 95% CI, 0.4 to 0.6) had positive results on both culture and PCR assay. The sensitivity and specificity of the liquid-saliva PCR assay were 100% (95% CI, 95.8 to 100) and 99.9% (95% CI, 99.9 to 100), respectively,
这上面的数据看得有点晕，我对不上了。算了下似乎总数不对啊。
能否指点一下呢？

蓝鱼o_0

回复 3# 桃子妖妖


    我觉得挺好啊。就以TB而言，目前以PCR为基础的快速鉴定，2小时就能知道结果。
大大缩短了时间。微生物实验室自动化过程，这些还是必要的。不仅仅着眼于临床，对于研究都很有好处。我听过ABI的技术员讲他们最新的设备，对未知细菌，不但可以快速分型（不需要再分G阳性或者阴性，数据库非常庞大，并且即时更新，匹配就能够知道细菌的种属，名称等信息），而且它可以分析进化树。可以进行溯源和追踪。比如究竟是来自于手还是来自于环境。我们都知道。现在PFGE一个实验就要两天。而且失败率很高，跑胶的时间，角度等参数对结果影响很大。自动化不但可以提高灵敏度，还可以有高特异度。

对ASC而言，通过Real timePCR，可以快速鉴定。JAMA2008年报道的universal screening就是用的这个方法。

当然这个成本也是比较高，ABI的仪器大概要300W。虽然有必要，但是不是必须。
所以各个实验室也要量力而为，进行成本效益分析。

蓝鱼o_0

回复 4# 绿茵场

可能是发病密度。我没有看全文。我只是有选择的看。这篇文献的意义在于：
通过RT PCR可以提高实验的灵敏度和特异度，很高（>99%）。
不同的标本信息，可以左右实验结果。

当然，您如果想要，我可以给您下载全文。

蓝鱼o_0

回复 2# toto

感兴趣的捧个钱场，不感兴趣捧个人场！

桃子妖妖

回复 5# 蓝鱼o_0
RT PCR在TB诊断中目前仍未普及啊，除了你说的成本效益对国内是重要原因外，我想敏感度、特性行到底如何？还有报告结果的时间？重要的是，如果凭临床、体征，价廉、简单的实验室检查就可以做出诊断不更好么（和抗菌药物的使用原则有雷同哈 ）？当然对于疑难病，对于做研究是可以的

蓝鱼o_0

回复 8# 桃子妖妖

总体来说，PCR为基础的方法，灵敏度和特异度都不错。缺点在于价格都不是很便宜。我们中心的病毒和细菌都是用PCR的方法进行诊断和鉴别。重复性也比较好。
这也根据各自医院的情况而言。新知识要批评接受，欣赏您的这种态度！