In:
Clinical Chemistry and Laboratory Medicine (CCLM), Walter de Gruyter GmbH, Vol. 59, No. 8 ( 2021-07-27), p. 1468-1476
Abstract:
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 values 〉 40) diagnoses. RT-PCR positive samples were assigned to diagnostic, screening, or monitoring groups of testing. Results With a limit of detection of 1.2 × 10 4 SARS-CoV-2 RNA copies/mL, Lumipulse showed positive percent agreement (PPA) of 79.9% (155/194) and negative percent agreement of 99.3% (397/400), whereas PPAs were 100% for samples with Ct values of 〈 18 or 18– 〈 25 and 92.5% for samples with Ct values of 25– 〈 30. By three groups, Lumipulse showed PPA of 87.0% (60/69), 81.1% (43/53), or 72.2% (52/72), respectively, whereas PPA was 100% for samples with Ct values of 〈 18 or 18– 〈 25, and was 94.4, 80.0, or 100% for samples with Ct values of 25– 〈 30, respectively. Additional testing of RT-PCR positive samples for SARS-CoV-2 subgenomic RNA showed that, by three groups, PPA was 63.8% (44/69), 62.3% (33/53), or 33.3% (24/72), respectively. PPAs dropped to 55.6, 20.0, or 41.7% for samples with Ct values of 25– 〈 30, respectively. All 101 samples with a subgenomic RNA positive result had a Lumipulse assay’s antigen positive result, whereas only 54 (58.1%) of remaining 93 samples had a Lumipulse assay’s antigen positive result. Conclusions Lumipulse assay was highly sensitive in samples with low RT-PCR Ct values, implying repeated testing to reduce consequences of false-negative results.
Type of Medium:
Online Resource
ISSN:
1437-4331
,
1434-6621
DOI:
10.1515/cclm-2021-0182
Language:
English
Publisher:
Walter de Gruyter GmbH
Publication Date:
2021
detail.hit.zdb_id:
1492732-9
SSG:
15,3
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