tetano
Editor, Senior Moderator
Clin Chem Lab Med
. 2023 Jan 19.
doi: 10.1515/cclm-2022-1039. Online ahead of print.
Evaluation of a high-sensitivity SARS-CoV-2 antigen test on the fully automated light-initiated chemiluminescent immunoassay platform
Minghang Yu[SUP] 1 2 3 [/SUP], Danying Chen[SUP] 1 2 3 [/SUP], Xiaomeng Tang[SUP] 1 2 3 [/SUP], Yuanyuan Zhang[SUP] 1 2 3 [/SUP], Pu Liang[SUP] 1 2 3 [/SUP], Yang Xiong[SUP] 1 2 3 [/SUP], Rui Li[SUP] 1 2 3 [/SUP], Rui Song[SUP] 3 [/SUP], Xiaoyou Chen[SUP] 3 [/SUP], Xuesen Zhao[SUP] 1 2 3 [/SUP], Xi Wang[SUP] 1 2 3 [/SUP], Ronghua Jin[SUP] 1 2 3 4 [/SUP]
Affiliations
Abstract
Objectives: To describe a high-sensitivity SARS-CoV-2 antigen test that is based on the fully automated light-initiated chemiluminescent immunoassay (LiCA[SUP]®[/SUP]), and to validate its analytical characteristics and clinical agreement on detecting SARS-CoV-2 infection against the reference molecular test.
Methods: Analytical performance was validated and detection limits were determined using different types of nucleocapsid protein samples. 798-pair anterior nasal swab specimens were collected from hospitalized patients and asymptomatic screening individuals. Agreement between LiCA[SUP]®[/SUP] antigen and real-time reverse transcription polymerase chain reaction (rRT-PCR) was evaluated.
Results: Repeatability and within-lab precision were 1.6-2.3%. The C[SUB]5[/SUB]∼C[SUB]95[/SUB] interval was -5.1-4.6% away from C[SUB]50[/SUB]. Detection limits in average (SD) were 325 (±141) U/mL on the national reference panel, 0.07 (±0.04) TCID[SUB]50[/SUB]/mL on active viral cultures, 0.27 (±0.09) pg/mL on recombinant nucleocapsid proteins and 1.07 (±1.01) TCID[SUB]50[/SUB]/mL on inactivated viral suspensions, respectively. LiCA detected a median of 374-fold (IQR 137-643) lower levels of the viral antigen than comparative rapid tests. As reference to the rRT-PCR method, overall sensitivity and specificity were determined to be 97.5% (91.4-99.7%) and 99.9% (99.2-100%), respectively. Total agreement between both methods was 99.6% (98.7-99.9%) with Cohen's kappa 0.98 (0.96-1). A positive detection rate of 100% (95.4-100%) was obtained as Ct≤37.8.
Conclusions: The LiCA[SUP]®[/SUP] system provides an exceptionally high-sensitivity and fully automated platform for the detection of the SARS-CoV-2 antigen in nasal swabs. The assay may have high potential use for large-scale population screening and surveillance of COVID-19 as an alternative to the rRT-PCR test.
Keywords: LiCA®; SARS-CoV-2; coronavirus disease 2019; high-sensitivity; light-initiated chemiluminescent assay; rRT-PCR.
. 2023 Jan 19.
doi: 10.1515/cclm-2022-1039. Online ahead of print.
Evaluation of a high-sensitivity SARS-CoV-2 antigen test on the fully automated light-initiated chemiluminescent immunoassay platform
Minghang Yu[SUP] 1 2 3 [/SUP], Danying Chen[SUP] 1 2 3 [/SUP], Xiaomeng Tang[SUP] 1 2 3 [/SUP], Yuanyuan Zhang[SUP] 1 2 3 [/SUP], Pu Liang[SUP] 1 2 3 [/SUP], Yang Xiong[SUP] 1 2 3 [/SUP], Rui Li[SUP] 1 2 3 [/SUP], Rui Song[SUP] 3 [/SUP], Xiaoyou Chen[SUP] 3 [/SUP], Xuesen Zhao[SUP] 1 2 3 [/SUP], Xi Wang[SUP] 1 2 3 [/SUP], Ronghua Jin[SUP] 1 2 3 4 [/SUP]
Affiliations
- PMID: 36656975
- DOI: 10.1515/cclm-2022-1039
Abstract
Objectives: To describe a high-sensitivity SARS-CoV-2 antigen test that is based on the fully automated light-initiated chemiluminescent immunoassay (LiCA[SUP]®[/SUP]), and to validate its analytical characteristics and clinical agreement on detecting SARS-CoV-2 infection against the reference molecular test.
Methods: Analytical performance was validated and detection limits were determined using different types of nucleocapsid protein samples. 798-pair anterior nasal swab specimens were collected from hospitalized patients and asymptomatic screening individuals. Agreement between LiCA[SUP]®[/SUP] antigen and real-time reverse transcription polymerase chain reaction (rRT-PCR) was evaluated.
Results: Repeatability and within-lab precision were 1.6-2.3%. The C[SUB]5[/SUB]∼C[SUB]95[/SUB] interval was -5.1-4.6% away from C[SUB]50[/SUB]. Detection limits in average (SD) were 325 (±141) U/mL on the national reference panel, 0.07 (±0.04) TCID[SUB]50[/SUB]/mL on active viral cultures, 0.27 (±0.09) pg/mL on recombinant nucleocapsid proteins and 1.07 (±1.01) TCID[SUB]50[/SUB]/mL on inactivated viral suspensions, respectively. LiCA detected a median of 374-fold (IQR 137-643) lower levels of the viral antigen than comparative rapid tests. As reference to the rRT-PCR method, overall sensitivity and specificity were determined to be 97.5% (91.4-99.7%) and 99.9% (99.2-100%), respectively. Total agreement between both methods was 99.6% (98.7-99.9%) with Cohen's kappa 0.98 (0.96-1). A positive detection rate of 100% (95.4-100%) was obtained as Ct≤37.8.
Conclusions: The LiCA[SUP]®[/SUP] system provides an exceptionally high-sensitivity and fully automated platform for the detection of the SARS-CoV-2 antigen in nasal swabs. The assay may have high potential use for large-scale population screening and surveillance of COVID-19 as an alternative to the rRT-PCR test.
Keywords: LiCA®; SARS-CoV-2; coronavirus disease 2019; high-sensitivity; light-initiated chemiluminescent assay; rRT-PCR.