Lumipulse G SARS-CoV-2 Ag assay evaluation using clinical samples from different testing groups

Abstract Objectives Compared to RT-PCR, lower performance of antigen detection assays, including the Lumipulse G SARS-CoV-2 Ag assay, may depend on specific testing scenarios. Methods We tested 594 nasopharyngeal swab samples from individuals with COVID-19 (RT-PCR cycle threshold [Ct] values ≤ 40) or non-COVID-19 (Ct >40) diagnoses. RT-PCR positive were assigned diagnostic, screening, monitoring groups testing. Results With a limit 1.2 × 10 4 RNA copies/mL, showed percent agreement (PPA) 79.9% (155/194) and negative 99.3% (397/400), whereas PPAs 100% for Ct <18 18–<25 92.5% 25–<30. By three groups, PPA 87.0% (60/69), 81.1% (43/53), 72.2% (52/72), respectively, was 18–<25, 94.4, 80.0, 25–<30, respectively. Additional subgenomic that, by 63.8% (44/69), 62.3% (33/53), 33.3% (24/72), dropped 55.6, 20.0, 41.7% All 101 result had assay’s result, only 54 (58.1%) remaining 93 result. Conclusions assay highly sensitive in low values, implying repeated reduce consequences false-negative results.