Clinical Performance of the Luminex NxTAG CoV Extended Panel for SARS-CoV-2 Detection in Nasopharyngeal Specimens from COVID-19 Patients in Hong Kong.
Luminex NxTAG CoV扩展组在香港SARS-CoV-2例患者鼻咽标本中进行新型冠状病毒肺炎检测的临床性能。
- 作者列表："Chen JH","Yip CC","Chan JF","Poon RW","To KK","Chan KH","Cheng VC","Yuen KY
:In December 2019, the coronavirus disease 2019 (COVID-19) pandemic caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) was first reported in the Hubei province of China and later spread all over the world. There was an urgent need of a high-throughput molecular test for screening the COVID-19 patients in the community. The Luminex NxTAG CoV extended panel is a high-throughput FDA emergency use-authorized molecular diagnostic assay for SARS-CoV-2 detection. This system targets three genes (ORF1ab, N, and E genes) of SARS-CoV-2, the ORF1ab region of SARS-CoV, and the ORF5 region of MERS-CoV. In this study, we evaluated the diagnostic performance of this system with nasopharyngeal swab specimens of 214 suspected COVID-19 patients in Hong Kong. The results were compared with our routine COVID-19 reverse transcription-PCR (RT-PCR) protocol with a LightMix SarbecoV E-gene kit and an in-house RdRp/Hel RT-PCR assay. The NxTAG CoV extended panel demonstrated 97.8% sensitivity and 100% specificity to SARS-CoV-2 in nasopharyngeal specimens. On low-viral load specimens, the sensitivity of the NxTAG panel could still maintain at 85.71%. Strong agreement was observed between the NxTAG panel and the routine COVID-19 RT-PCR protocol (kappa value = 0.98). Overall, the E gene target of the NxTAG panel demonstrated the highest sensitivity among the three SARS-CoV-2 targets, while the N gene targets demonstrated the least. In conclusion, the NxTAG CoV extended panel is simple to use, and it has high diagnostic sensitivity and specificity to SARS-CoV-2 in nasopharyngeal specimens. We recommend this diagnostic system for high-throughput COVID-19 screening in the community.
: 2019年12月，由严重急性呼吸综合征冠状病毒-2 (新型冠状病毒肺炎) 引起的冠状病毒疾病2019 (SARS-CoV-2) 大流行在中国湖北省首次报告，后在全球蔓延。迫切需要一种高通量分子检测方法来筛查社区中的新型冠状病毒肺炎名患者。Luminex NxTAG CoV扩展面板是一种高通量FDA紧急使用授权的分子诊断检测方法，用于SARS-CoV-2检测。该系统靶向传染性非典型肺炎-CoV-2的三个基因 (ORF1ab、N和E基因) 、传染性非典型肺炎-CoV的ORF1ab区域和MERS-CoV的ORF5区域。在这项研究中，我们用香港214名疑似新型冠状病毒肺炎名患者的鼻咽拭子标本评估了该系统的诊断性能。将结果与我们使用LightMix SarbecoV E-gene试剂盒和内部RdRp/Hel rt-pcr检测的常规新型冠状病毒肺炎逆转录-PCR (rt-pcr) 方案进行比较。NxTAG CoV扩展组在鼻咽样本中证明了对SARS-CoV-2的97.8% 敏感性和100% 特异性。在低病毒载量样本上，NxTAG面板的灵敏度仍可维持在85.71%。在NxTAG组和常规新型冠状病毒肺炎rt-pcr方案之间观察到强烈的一致性 (kappa值 = 0.98)。总体而言，NxTAG组的E基因靶标在三个SARS-CoV-2个靶标中表现出最高的灵敏度，而N基因靶标表现出最低。总之，NxTAG CoV扩展面板使用简单，在鼻咽标本中具有较高的诊断灵敏度和特异性，达到SARS-CoV-2。我们推荐这种诊断系统用于社区的高通量新型冠状病毒肺炎筛查。
METHODS::The cytologic evaluation of serous effusions may be challenging for a number of reasons. Distinction of benign, reactive conditions from malignancy represents the main focus when examining these specimens. The morphologic diagnosis of malignancy may be difficult due to the relative paucity of abnormal cells. In other situations, cellularity is not an issue, but the ability to confidently identify a second, foreign (i.e., tumor) population within a background mesothelial cells on the basis of cytomorphologic features alone may pose problems. Cases with definitive morphologic evidence of malignancy may require additional studies in order to determine the tumor subtype and, in the case of carcinoma, the primary site of origin. Cases in which a definitive and precise diagnosis of malignancy is made may be optimal candidates for further molecular testing in order to gain prognostic information and guide personal therapeutic decisions. Finally, while an inflammatory or infectious condition can be suggested on the basis of cellular components and associated background elements, the identification of causative agent(s) may be difficult without additional studies. In all of these situations, the use of ancillary studies and techniques is critical; their utility and appropriate application are the subject of this review.
METHODS:OBJECTIVE:To assess the rate of, and risk factors for, human cytomegalovirus viremia (HCMV) in donor+/recipient+ (HCMV serostatus matched) hematopoietic stem-cell transplantation (HSCT) recipients. METHODS:HCMV DNA from 144 donor+/recipient+ HSCT recipients was examined by quantitative polymerase chain reaction (qPCR). RESULTS:The cumulative incidence of HCMV viremia was 69.4% (100/144) during the 48 weeks after HSCT. In a multivariate analysis, acute graft-versus-host disease (aGVHD) was discovered to be a risk factor for the occurrence of HCMV viremia (P = .006). The cumulative incidence of HCMV viremia and increasing DNA loads were significantly associated with aGVHD occurrence (P = .001 for each). The occurrence of late-term HCMV viremia was associated with aGVHD (P = .001) and a higher DNA load during the first 12 weeks after HSCT (P = .04). CONCLUSIONS:aGVHD is a risk factor for HCMV viremia. Recipients with aGVHD who have a high HCMV DNA load should be strictly monitored to prevent HCMV activation.
METHODS:OBJECTIVES:Malaria is one of most common tropical diseases encountered in travellers and migrants. It requires an urgent and reliable diagnosis considering its potential severity. In this study, performance of five diagnostic assays were evaluated in a nonendemic region and compared prospectively to quantitative PCR (qPCR). METHODS:A prospective study was conducted at Toulouse Hospital from August 2017 to January 2018 and included all patients with initial Plasmodium screening. Thin and thick blood smears (TnS, TkS), quantitative buffy coat (QBC), rapid diagnostic tests (RDTs) and commercial loop-mediated isothermal amplification (LAMP) were independently performed on each blood sample and compared to our qPCR reference standard. RESULTS:The study encompassed 331 patients, mainly returning from Africa. qPCR detected 73 Plasmodium-positive samples (including 58 falciparum). Individually, LAMP had a 97.3% (71/73) sensitivity, far ahead of TnS (84.9%, 62/73), TkS (86.3%, 63/73), QBC (86.3%, 63/73) and RDT (86.3%, 63/73). RDT demonstrated a high sensitivity for falciparum (98.3%, 57/58) but missed all ovale, malariae and knowlesi infections. Specificity was excellent for all techniques (99.6-100%). The most sensitive diagnosis strategies were TnS + RDT (95.9%, 70/73), TnS + LAMP (97.3%, 71/73) and TnS + RDT + LAMP (100%, 73/73), about 10% higher than strategies using exclusively microscopy, TkS + TnS (87.7%, 64/73) or QBC + TnS (87.7%, 64/73). TnS remains necessary for Plasmodium species identification and quantification. Adding sequentially TnS only on LAMP-positive samples did not decrease TnS + LAMP strategy sensitivity. CONCLUSIONS:In nonendemic countries, the currently recommended microscopy-based strategies seem unsatisfactory for malaria diagnosis considering RDT and LAMP performance, two rapid and sensitive assays that require limited training.