Laboratory demonstration of a prozone-like effect in HRP2-detecting malaria rapid diagnostic tests: implications for clinical management.
Laboratory demonstration of a prozone-like effect in HRP2-detecting malaria rapid diagnostic tests: implications for clinical management.
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DOI：
10.1186/1475-2875-10-286
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发表时间：
2011-09-29
期刊：
影响因子：
3
通讯作者：
Bell D
中科院分区：
文献类型：
--
作者：
Luchavez J;Baker J;Alcantara S;Belizario V Jr;Cheng Q;McCarthy JS;Bell D
疟疾快速诊断测试（RDTs）现在被广泛用于缺乏可靠显微镜检查的偏远流行地区的快速现场诊断。异常结果，即在高寄生虫密度下出现阴性检测结果，十多年来一直有各种报道，并导致对临床使用中检测可靠性的质疑。在第一项试验中，在HRP 2检测RDT上检测重组HRP 2抗原的系列稀释液。在第二项试验中，针对三种HRP 2检测RDT测试了培养物衍生的恶性疟原虫寄生虫的系列稀释液。在高浓度的靶抗原富组氨酸蛋白-2（高于15，000 ng/ml）（相当于每μL超过312，000个寄生虫）下，RDT中出现了前带样效应。在三种RDT产品上观察到相似的结果，使用培养寄生虫的稀释液，寄生虫密度高达25%。虽然观察到线强度降低，但未发生假阴性结果。这些结果表明，假阴性疟疾RDT结果将很少发生，由于prozone样的影响，在高密度感染，和其他原因更有可能。然而，RDT线强度是很差的指示寄生虫密度在高密度感染和RDTs，因此，不应被视为定量。对疑似严重疟疾的立即管理应依靠临床评估或显微镜检查。在疟疾RDT产品开发和批放行检测中，应考虑针对高浓度抗原的评价，以确保在临床可能观察到的抗原浓度下不会出现非常弱或假阴性结果。
Malaria rapid diagnostic tests (RDTs) are now widely used for prompt on-site diagnosis in remote endemic areas where reliable microscopy is absent. Aberrant results, whereby negative test results occur at high parasite densities, have been variously reported for over a decade and have led to questions regarding the reliability of the tests in clinical use. In the first trial, serial dilutions of recombinant HRP2 antigen were tested on an HRP2-detectiing RDT. In a second trial, serial dilutions of culture-derived Plasmodium falciparum parasites were tested against three HRP2-detecting RDTs. A prozone-like effect occurred in RDTs at a high concentration of the target antigen, histidine-rich protein-2 (above 15,000 ng/ml), a level that corresponds to more than 312000 parasites per μL. Similar results were noted on three RDT products using dilutions of cultured parasites up to a parasite density of 25%. While reduced line intensity was observed, no false negative results occurred. These results suggest that false-negative malaria RDT results will rarely occur due to a prozone-like effect in high-density infections, and other causes are more likely. However, RDT line intensity is poorly indicative of parasite density in high-density infections and RDTs should, therefore, not be considered quantitative. Immediate management of suspected severe malaria should rely on clinical assessment or microscopy. Evaluation against high concentrations of antigen should be considered in malaria RDT product development and lot-release testing, to ensure that very weak or false negative results will not occur at antigen concentrations that might be seen clinically.
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DOI：
10.1590/s0036-46652003000600004
发表时间：
2003-12-01
期刊：
Revista do Instituto de Medicina Tropical de São Paulo
影响因子：
--
作者：
Sato, Neuza Satomi;Melo, Carmen Silvia de;Ueda, Mirthes
通讯作者：
Ueda, Mirthes
影响因子：
168.9
作者：
BEADLE, C;LONG, GW;HOFFMAN, SL
通讯作者：
HOFFMAN, SL
影响因子：
9.4
作者：
Forney, JR;Magill, AJ;Gasser, RA
通讯作者：
Gasser, RA
影响因子：
3.7
作者：
Gamboa D;Ho MF;Bendezu J;Torres K;Chiodini PL;Barnwell JW;Incardona S;Perkins M;Bell D;McCarthy J;Cheng Q
通讯作者：
Cheng Q
影响因子：
28.5
作者：
Talamo G;Castellani W;Dolloff NG
通讯作者：
Dolloff NG