Comparison of the Accula SARS-CoV-2 Test with a Laboratory-Developed Assay for Detection of SARS-CoV-2 RNA in Clinical Nasopharyngeal Specimens.

Accula SARS-CoV-2检测与实验室开发的检测临床鼻咽标本中SARS-CoV-2 RNA的比较。

  • 影响因子:3.65
  • DOI:10.1128/JCM.01072-20
  • 作者列表:"Hogan CA","Garamani N","Lee AS","Tung JK","Sahoo MK","Huang C","Stevens B","Zehnder J","Pinsky BA
  • 发表时间:2020-07-23

:Several point-of-care (POC) molecular tests have received emergency use authorization (EUA) from the Food and Drug Administration (FDA) for the diagnosis of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The test performance characteristics of the Accula (Mesa Biotech) SARS-CoV-2 POC test need to be evaluated to inform its optimal use. The aim of this study was to assess the test performance of the Accula SARS-CoV-2 test. The performance of the Accula test was assessed by comparing results of 100 nasopharyngeal swab samples previously characterized by the Stanford Health Care EUA laboratory-developed test (SHC-LDT), targeting the envelope (E) gene. Assay concordance was assessed by overall percent agreement, positive percent agreement (PPA), negative percent agreement (NPA), and Cohen's kappa coefficient. Overall percent agreement between the assays was 84.0% (95% confidence interval [CI], 75.3 to 90.6%), PPA was 68.0% (95% CI, 53.3 to 80.5%), and the kappa coefficient was 0.68 (95% CI, 0.54 to 0.82). Sixteen specimens detected by the SHC-LDT were not detected by the Accula test and showed low viral load burden, with a median cycle threshold value of 37.7. NPA was 100% (95% CI, 94.2 to 100%). Compared to the SHC-LDT, the Accula SARS-CoV-2 test showed excellent negative agreement. However, positive agreement was low for samples with low viral load. The false-negative rate of the Accula POC test calls for a more thorough evaluation of POC test performance characteristics in clinical settings and for confirmatory testing in individuals with moderate to high pretest probability of SARS-CoV-2 who test negative on Accula.


: 一些即时 (POC) 分子测试已经获得了食品和药物管理局 (FDA) 的紧急使用授权 (EUA),用于诊断新型冠状病毒 (SARS-CoV-2)。需要评估Accula (Mesa Biotech) SARS-CoV-2 POC测试的测试性能特征,以告知其最佳用途。本研究的目的是评估Accula SARS-CoV-2测试的测试性能。通过比较先前由Stanford Health Care EUA实验室开发的针对包膜 (E) 基因的测试 (shc-ldt) 表征的100个鼻咽拭子样品的结果来评估Accula测试的性能。通过总体一致性百分比、阳性一致性百分比 (PPA) 、阴性一致性百分比 (NPA) 和Cohen kappa系数评估试验一致性。试验之间的总体一致性百分比为84.0% (95% 置信区间 [CI],75.3至90.6%),PPA为68.0% (95% CI,53.3至80.5%),kappa系数为0.68 (95% CI,0.54至0.82)。通过shc-ldt检测到的16个样本没有通过Accula测试检测到,并且显示低病毒载量,中值周期阈值为37.7。NPA为100% (95% CI,94.2 ~ 100%)。与shc-ldt相比,Accula SARS-CoV-2测试显示出极好的阴性一致性。然而,阳性协议是低病毒载量低的样品。Accula POC测试的假阴性率要求对临床环境中的POC测试性能特征进行更彻底的评估,并在Accula测试阴性的中度至高测试前概率为SARS-CoV-2的个体中进行验证性测试。



来源期刊:Acta cytologica
作者列表:["Yu GH","Glaser LJ","Gustafson KS"]

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.

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来源期刊:Laboratory medicine
作者列表:["Yang R","Zhang R","Zhang Y","Huang Y","Liang H","Gui G","Gong S","Wang H","Xu M","Fan J"]

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.

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作者列表:["Charpentier E","Benichou E","Pagès A","Chauvin P","Fillaux J","Valentin A","Guegan H","Guemas E","Salabert AS","Armengol C","Menard S","Cassaing S","Berry A","Iriart X"]

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.

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