Retrospective clinical evaluation of 4 lateral flow assays for the detection of SARS-CoV-2 IgG

Abstract

In a Clinical Laboratory Improvement Amendments laboratory setting, we evaluated severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) IgG detection with 4 lateral flow immunoassays [LFIAs; 2 iterations from BTNX Inc. ( n = 457) and 1 each from ACON Laboratories ( n = 200) and SD BIOSENSOR ( n = 155)]. In a cohort of primarily hospitalized, reverse-transcription polymerase chain reaction–confirmed coronavirus disease 2019 cases, sensitivity at ≥14 days from symptom onset was: BTNX kit 1, 95%; BTNX kit 2, 91%; ACON, 95%; and SD, 92%. All assays showed good concordance with the Abbott SARS-CoV-2 IgG assay at ≥14 days from symptom onset: BTNX kit 1, 99%; BTNX kit 2, 94%; ACON, 99%; and SD, 100%. Specificity, measured using specimens collected prior to SARS-CoV-2 circulation in the United States and “cross-reactivity challenge” specimens, was 98% for BTNX kit 1 and ACON and 100% for BTNX kit 2 and SD. These results suggest that LFIAs may provide adequate results for rapid detection of SARS-CoV-2.

SafeSwab, a sample collection and dispensing device for near-patient testing

“…Despite all patients having documented PCR results, three antibody tests were negative. A previous study showed this antibody test to be highly accurate in a set of samples drawn in the first 1-4 weeks after diagnosis (9). It is possible that antibody levels in these three patients had decreased, or that they had a low response; variability in anti-SARS-CoV-2 IgG response is well documented (10).…”

Current molecular diagnostics assays for SARS-CoV-2 and emerging variants

“…The surface antigen conjugated with gold nanoparticles is used here as a capture Sensitivity = 88.63% Li et al (2020) Optical (Interferometry) The sensor is developed based on an interferometric bimodal waveguide whose surface is modified with specific receptors targeting antigens of SARS-CoV2 such a spike protein. When virus particles are captured by receptors, interferometric signals are recorded Sensitivity = greater than 95% Ruiz-Vega, Soler, and Lechuga (2021) Plasmonic Sensor Optical detection of SARS-CoV2 virus done using the specific monoclonal antibody and ACE2 protein 370 virus particles/mL Huang et al (2021) LFA Evaluation of four lateral flow assay kits for detection of SARS-CoV2 IgG Sensitivities: BTNX kit 1 = 95% BTNX kit 2 = 91% ACON = 95% SD Biosensor = 92% McAulay et al (2020) LFIA Detection method for SARS-CoV2 spike 1 protein using a combination of capture and detector molecule being SARS-CoV2 receptor ACE2 and commercially available antibodies for S1 respectively 1.86 × 10 5 copies/mL Lee et al (2021) Quartz Crystal Microbalance (Piezo) S1 spike protein of SARS-CoV2 is detected with the help of anti-spike glycoprotein (engineered surface with mixed SAM of CH3 and COOH + antibody) 40 nM Pandey (2020) Amplification and Microfluidic device SARS-CoV2 N gene and SARS-CoV2 S gene are being detected using isothermal amplification analyser (RTisochip). The chip is able to detect 19 common respiratory viruses as well S gene = 10 copies/μL; N gene = 25 copies/μL Xing et al (2020) Chromatographic immunoassay Standard Q COVID-19 antigen (SD Biosensor) for detection of SARS-CoV2 nucleoprotein in nasopharyngeal swabs Sensitivity = 70.6% Cerutti et al (2020) …”

AuNP Coupled Rapid Flow-Through Dot-Blot Immuno-Assay for Enhanced Detection of SARS-CoV-2 Specific Nucleocapsid and Receptor Binding Domain IgG

“…There are numerous reports on rapid lateral flow immunochromatographic assay systems for SARS-CoV-2 antibody detection. 7,[26][27][28][29] However, LFIA systems have a higher possibility of the false-negative signal depending on the immobilized analyte concentration compared to the flow-through system. 30,31 Here, we have developed a flow-through detection system with biofunctionalized colloidal gold nanoparticles (AuNP).…”