Journal of clinical virology : the official publication of the Pan American Society for Clinical Virology
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The aim of the present study was to evaluate the clinical performance of four SARS-CoV-2 immunoassays and their contribution in routine care for the diagnosis of COVID-19, in order to benefit of robust data before their extensive use. ⋯ Serology was complementary to RT-PCR for the diagnosis of COVID-19 at least 14 days after onset of symptoms. First line serology testing can be performed with Wantai Ab or Abbott IgG assays, while DiaPro IgG confirmation assay can be used as an efficient confirmation assay.
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The severe acute respiratory syndrome coronavirus (SARS-CoV-2) pandemic has resulted in significant shortages of RT-PCR testing supplies including RNA extraction kits. The goal of our study was to determine if a simplified heat-RNA release method would provide comparable detection of SARS-CoV-2 without the need for nucleic acid extraction. ⋯ Five samples that were missed by heat-RNA release method had a mean Ct value: 35 using the automated extraction instrument, indicating a very low viral load. Our findings show that a simple heat-RNA release method is a reasonable alternative for the majority of COVID-19 positive patients and can help overcome the cost and availability issues of RNA extraction reagents.
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Molecular assays based on reverse transcription-loop-mediated isothermal amplification (RT-LAMP) may be useful for rapid diagnosis of the severe acute respiratory syndrome Coronavirus-2 (SARS-CoV-2) because of the easy performance and the option to bypass RNA extraction. ⋯ The variplex RT-LAMP may serve as a rapid test to be combined with a RT-PCR assay to increase the diagnostic accuracy in patients with suspected COVID-19 infection.
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SARS-CoV-2 testing demand has outpaced its supply. Pooling samples for lower risk populations has the potential to accommodate increased demand for SARS-CoV-2 molecular testing. ⋯ We report that 1:4 pooling of samples is specific and associated with an expected 2 CT loss in analytical sensitivity. Instead of running each sample individually, pooling of four samples will allow for a greater throughput and conserve scarce reagents.
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Observational Study
SARS-CoV-2 antibodies, serum inflammatory biomarkers and clinical severity of hospitalized COVID-19 patients.
The involvement of SARS-CoV-2 antibodies in mediating immunopathogenetic events in COVID-19 patients has been suggested. By using several experimental approaches, we investigated the potential association between SARS-CoV-2 IgGs recognizing the spike (S) protein receptor-binding domain (RBD), neutralizing antibodies (NtAb) targeting S, and COVID-19 severity. ⋯ The data presented herein do not support an association between SARS-CoV-2 RBD IgG or NtAb50 levels and COVID-19 severity.