Fundação Oswaldo Cruz, Instituto René Rachou, Pesquisa Clínica e Políticas Públicas em Doenças Infecciosas e Parasitárias, Belo Horizonte, MG, Brazil.
Biomed Res Int. 2019 Jul 24;2019:8240784. doi: 10.1155/2019/8240784. eCollection 2019.
Visceral leishmaniasis (VL) is considered a major public health concern in Brazil and several regions of the world. A recent advance in the diagnosis of infectious diseases was the development of loop-mediated isothermal amplification (LAMP). The aim of this study was to develop and evaluate a new LAMP assay for detection of K26 antigen-coding gene of complex. A total of 219 blood samples of immunocompetent patients, including 114 VL cases and 105 non-VL cases, were analyzed for the diagnosis of VL in the present study. Diagnostic accuracy was calculated against a combination of parasitological and/or serological tests as a reference standard. The results were compared to those of kDNA PCR. The detection limit for the K26-Lamp assay was 1fg purified DNA and 100 parasites/mL within 60 min of amplification time with visual detection for turbidity. The assay was specific for complex. Sensitivity, specificity, and accuracy were 98.2%, 98.1%, and 98.2%, respectively, for K26-LAMP and 100%, 100%, and 100%, respectively, for kDNA -PCR. Excellent agreement was observed between K26-LAMP and kDNA PCR assays (K = 0.96). A highly sensitive and specific LAMP assay targeting K26 antigen-coding gene of complex was developed for diagnosis in peripheral blood samples of VL patients.
内脏利什曼病（VL）被认为是巴西和世界上几个地区的主要公共卫生关注点。传染病诊断的一个最新进展是环介导等温扩增（LAMP）的发展。本研究的目的是开发和评估一种新的 LAMP 检测方法，用于检测 复合体的 K26 抗原编码基因。本研究共分析了 219 份免疫功能正常患者的血液样本，包括 114 例 VL 病例和 105 例非 VL 病例，以诊断 VL。诊断准确性是针对寄生虫学和/或血清学检测的组合作为参考标准计算的。结果与 kDNA PCR 进行了比较。K26-Lamp 检测的检测限为 1fg 纯化 DNA 和 60 分钟扩增时间内 100 个寄生虫/mL，通过浊度的视觉检测进行检测。该检测方法对 复合体具有特异性。K26-LAMP 的敏感性、特异性和准确性分别为 98.2%、98.1%和 98.2%，kDNA-PCR 分别为 100%、100%和 100%。K26-LAMP 和 kDNA PCR 检测之间观察到极好的一致性（K=0.96）。针对 复合体的 K26 抗原编码基因，开发了一种用于 VL 患者外周血样本诊断的高灵敏度和特异性 LAMP 检测方法。
