JID：LAMP试剂盒诊断疟疾快速准确

自19世纪80年代以来，外周血涂片镜检法一直是诊断疟疾的金标准。而快速抗原测定试验（RDT）从20世纪90年代早期就被用来诊断疟疾，促进了疟疾快速诊断的发展。虽然RDT和镜检已经满足了疟疾流行人群中病人管理的要求，但是，人们越来越关注于发展诊断无症状低密度寄生虫个体的方法。PCR法敏感度高但是耗时长，常需要10-16个小时才能得到结果，而敏感度较低的镜检只需要60分钟。另外，实时定量PCR只要3-5个小时就能检测到寄生虫的DNA，但是敏感度比巢式PCR低。

最近的一些研究表明，针对疟疾的环介导扩增试验（LAMP）能在封闭系统中进行等温分子扩增，耗时一个多小时就能达到与PCR法相当的准确度，且对实验室的要求也较低。为了研究LAMP 试剂盒诊断输入疟疾的准确性，来自英国伦敦热带病医院的Spencer D.  POLLEY和同事进行了一项研究，研究结果在线发表在2013年4月30日的Journal of Infectious Diseases上。研究发现，LAMP法能够快速准确地诊断疟疾。

研究者将已回国旅行者的序贯血液样本送到专业寄生虫实验室检测病原体，来评估LAMP试剂盒的诊断意义。研究人员进行了镜检、疟疾LAMP，并平行开展了疟原虫种类和恶性疟原虫特异性试验。按照参考标准，对所有样本进行了巢式PCR实验。衡量诊断准确性的主要结局指标是比较LAMP和巢式PCR的敏感性和特异性。

初步统计分析共涉及705个样本。LAMP法对恶性疟原虫引物的敏感度和特异性分别是98.4%和98.1%，而种类引物敏感度和特异性分别是97.0%和99.2%。对15个有差异的测试结果进行重复PCR分析，发现其中4个的结果是与LAMP一致的，这就意味着初步分析低估了LAMP的诊断准确性。因此，耗时更少的疟疾LAMP试剂盒诊断的准确性与巢式PCR相似，高于镜检。

Clinical Evaluation of a LAMP test kit for Diagnosis of Imported Malaria.
Abstract
Background. Diagnosis of malaria relies on parasite detection by microscopy or antigen detection; both fail to detect low density infections. New tests providing rapid, sensitive diagnosis, with minimal need for training would enhance both malaria diagnosis and malaria control activities. We determined the diagnostic accuracy, in febrile returned travelers, of a new malaria LAMP kit.Methods. The kit was evaluated in sequential blood samples from returned travelers sent for pathogen testing to a specialist parasitology laboratory. Microscopy was performed, then malaria LAMP using Plasmodium genus and P. falciparum-specific tests in parallel. Nested PCR was performed on all samples as the reference standard. Primary outcome measures for diagnostic accuracy were sensitivity and specificity of LAMP results compared to nested PCR.Results. 705 samples were tested in the primary analysis. Sensitivity and specificity of the LAMP P. falciparum primers were 98.4% and 98.1%, respectively, and 97.0% and 99.2% for the genus primers. Post-hoc repeat PCR analysis of all 15 discrepant tests resolved four of these in favor of LAMP, suggesting that the primary analysis had underestimated diagnostic accuracy.Conclusions. Malaria LAMP performed with similar diagnostic accuracy to nested PCR, with greatly reduced time to result, and was superior to expert microscopy.