Corstjens Paul L A M, de Dood Claudia J, Priest Jeffrey W, Tanke Hans J, Handali Sukwan
Department of Molecular Cell Biology, Leiden University Medical Center, Leiden, The Netherlands.
Division of Parasitic Diseases and Malaria, Centers for Disease Control and Prevention, Atlanta, Georgia, United States of America.
PLoS Negl Trop Dis. 2014 Jul 3;8(7):e2944. doi: 10.1371/journal.pntd.0002944. eCollection 2014 Jul.
Neurocysticercosis is a frequent parasitic infection of the human brain, occurring in most of the world, and requires imaging of the brain to diagnose. To determine the burden of disease and to simplify diagnosis, a field-friendly rapid lateral flow (LF) based antibody screening test was developed. The assay utilizes novel nano-sized up-converting phosphor (UCP) reporter particles in combination with a portable lightweight analyzer and detects antibodies in serum samples reactive with bacterial-expressed recombinant (r) T24H, a marker for detecting neurocysticercosis cases. Three sequential flow steps allow enrichment of antibodies on the Test (T) line and consecutive binding of protein-A coated UCP reporter particles. Antibody binding was determined by measuring 550 nm emission after excitation of the UCP label with a 980 nm infrared (IR) diode. Clinical sensitivity and specificity of the assay to detect cases of human neurocysticercosis with 2 or more viable brain cysts were 96% and 98%, respectively, using a sample set comprised of sera from 63 confirmed cases and 170 healthy parasite-naïve non-endemic controls.
Proof-of-principle, of a rapid UCP-LF screening assay for neurocysticercosis was demonstrated. The assay utilized bacterial-expressed rT24H as a potential alternative for baculovirus-expressed rT24H. Performance of the UCP-LF assay was excellent, although further studies need to confirm that bacterial expressed antigen can entirely replace previously used baculovirus antigen. In addition, the increasing availability of commercial sources for UCP reporter materials as well as the accessibility of affordable semi-handheld scanners may allow UCP-based bioanalytical systems for point-of-care to evolve at an even faster pace.
神经囊尾蚴病是一种常见的人类脑部寄生虫感染，在世界大部分地区都有发生，需要进行脑部成像来诊断。为了确定疾病负担并简化诊断，开发了一种基于现场友好型快速侧向流动（LF）的抗体筛查试验。该检测方法利用新型纳米尺寸的上转换磷光体（UCP）报告颗粒与便携式轻型分析仪相结合，检测血清样本中与细菌表达的重组（r）T24H反应的抗体，rT24H是检测神经囊尾蚴病病例的标志物。三个连续的流动步骤可使抗体在检测（T）线上富集，并使蛋白A包被的UCP报告颗粒连续结合。通过用980nm红外（IR）二极管激发UCP标记后测量550nm发射来确定抗体结合情况。使用由63例确诊病例和170例健康的未感染寄生虫的非流行对照血清组成的样本集，该检测方法检测有2个或更多存活脑囊肿的人类神经囊尾蚴病病例的临床敏感性和特异性分别为96%和98%。
证明了一种用于神经囊尾蚴病的快速UCP-LF筛查试验的原理。该检测方法利用细菌表达的rT24H作为杆状病毒表达的rT24H的潜在替代品。UCP-LF检测方法的性能优异，尽管需要进一步研究以确认细菌表达的抗原能否完全替代先前使用的杆状病毒抗原。此外，UCP报告材料商业来源的增加以及价格合理的半手持式扫描仪的可及性，可能会使基于UCP的即时检测生物分析系统以更快的速度发展。
