Vaccine Development Laboratory, Microbiology Department, Institute of Biomedical Sciences, University of São Paulo, São Paulo, Brazil.
Instituto de Medicina Tropical de São Paulo, Universidade de São Paulo, São Paulo, Brazil.
Int J Infect Dis. 2020 Jun;95:276-278. doi: 10.1016/j.ijid.2020.04.012. Epub 2020 Apr 11.
This study was performed to determine whether Dengue virus (DENV) immunochromatographic tests can detect and differentiate nonstructural protein 1 (NS1) from each of the four DENV serotypes and do not cross-react with the Zika virus (ZIKV) NS1 protein.
We compared the specificity of six NS1-based DENV immunochromatographic tests (point of care) in the detection of NS1 proteins from each of the four DENV serotypes and ZIKV. The tests were performed with NS1 proteins produced in mammalian cells. Cross-reactivity was confirmed with a purified recombinant ZIKV NS1 protein and DENV or ZIKV human serum samples.
Cross-reaction was observed in 2 out of the 6 evaluated tests using cell culture supernatants containing NS1 protein of each tested virus. Cross-reactivity with ZIKV was confirmed with purified recombinant ZIKV NS1 produced in Escherichia coli. Further analyses with serum samples collected from DENV or ZIKV patients confirmed the cross-reactivity with ZIKV protein in 2 tests.
The detection of the NS1 protein is the basis for several commercially available serological DENV diagnostic tests. The present results emphasize the relevance of testing specificity of presently available NS1-based DENV serological tests and the need of adjustments of tests that cross-react with the ZIKV protein. Our results are particularly relevant for regions where both viruses are endemically found, as in the case of Brazil.
本研究旨在确定登革热病毒（DENV）免疫层析检测是否能检测和区分来自四个 DENV 血清型的非结构蛋白 1（NS1），并且不与寨卡病毒（ZIKV）的 NS1 蛋白发生交叉反应。
我们比较了 6 种基于 NS1 的 DENV 免疫层析检测（即时检测）在检测来自四个 DENV 血清型和 ZIKV 的 NS1 蛋白的特异性。这些检测是使用在哺乳动物细胞中产生的 NS1 蛋白进行的。用纯化的重组 ZIKV NS1 蛋白和 DENV 或 ZIKV 人血清样本进行交叉反应确认。
在用含有每个测试病毒的 NS1 蛋白的细胞培养上清液进行评估的 6 种检测中有 2 种观察到了交叉反应。用在大肠杆菌中产生的纯化重组 ZIKV NS1 证实了与 ZIKV 的交叉反应。用从 DENV 或 ZIKV 患者收集的血清样本进行的进一步分析证实了 2 种检测与 ZIKV 蛋白的交叉反应。
NS1 蛋白的检测是几种市售的血清学 DENV 诊断检测的基础。本研究结果强调了测试目前市售的基于 NS1 的 DENV 血清学检测的特异性的相关性，以及需要调整与 ZIKV 蛋白发生交叉反应的检测的必要性。我们的结果对于同时存在这两种病毒的地区特别重要，如巴西。
