A diagnostic accuracy study comparing RNA LAMP, direct LAMP, and rapid antigen testing from nasopharyngeal swabs

Abstract

IntroductionDuring the coronavirus disease 2019 (COVID-19) pandemic, the early detection and isolation of individuals infected with severe acute respiratory syndrome coronavirus disease 2 (SARS-CoV-2) through mass testing can effectively prevent disease transmission. SARS-CoV-2 nucleic acid rapid detection based on loop-mediated isothermal amplification (LAMP) may be appropriate to include in testing procedures.MethodsWe used 860 nasopharyngeal specimens from healthcare workers of Huashan Hospital and COVID-19 patients collected from April 7th to 21st, 2022, to assess the clinical diagnostic performance of the LAMP assay marketed by Shanghai GeneSc Biotech and compared it to the result of a rapid antigen test (RAT) head-to-head.ResultsOverall, the diagnostic performance of LAMP assay and RAT were as follows. The LAMP assay represented higher sensitivity and specificity than RAT, especially in the extracted RNA samples. The sensitivity was 70.92% and 92.91% for direct LAMP and RNA-LAMP assay, respectively, while the specificity was 99.86% and 98.33%. The LAMP assay had overall better diagnostic performance on the specimens with relatively lower Ct values or collected in the early phase (≤7 days) of COVID-19. The combination of LAMP assay and RAT improved diagnostic efficiency, providing new strategies for rapidly detecting SARS-CoV-2.ConclusionThe LAMP assay are suitable for mass screenings of SARS-CoV-2 infections in the general population.

Comparison of the diagnostic accuracy of the Pluslife Mini Dock RHAM technology with Abbott ID Now and Cepheid GenXpert: A retrospective evaluation study

“…Although isothermal nucleic acid amplification and LAMP are comparable to RAT in terms of simplicity, convenience, and rapidity, their sensitivity and specificity are far more superior 19,21,22 . Based on our experience and according to various studies, false negative RAT results have been observed in samples with a low viral load, particularly in samples with a C T > 25 [23][24][25] .…”

Laboratory Evaluation of a SARS-CoV-2 RT-LAMP Test

“…Reverse transcription loop-mediated isothermal amplification (RT-LAMP) assays have now also been developed for the diagnosis of SARS-CoV-2 [ 10 , 11 ]. RT-LAMP combines the advantages of Ag-RDTs as they are easy, rapid, and do not require specialized infrastructures [ 10 ] or real-time RT-PCR (high sensitivity) [ 10 , 11 , 12 , 13 ]. These properties make RT-LAMP an attractive candidate diagnostic test for implementation in LMICs.…”