Performance of an automated chemiluminescence SARS-CoV-2 IG-G assay

Lau, Chin Shern; Oh, Hong Choon; Hoo, S.P.; Liang, YL; Phua, Soon Kieng; Aw, Tar Choon

doi:10.1016/j.cca.2020.09.005

Cited by 21 publications

(40 citation statements)

References 25 publications

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“…In a study evaluating seven LFIAs [ 12 ], patients with lower IgM levels were more prone to produce borderline results on POCT testing; they found 6 asymptomatic RT-PCR positive COVID-19 patients who had repeated negative LFIA results. The sensitivities of the Architect and Cobas CLIAs are also different from our previous evaluations [ 1 , 2 ]. This is because the populations used in the previous studies were larger and had different demographics.…”

Section: Discussioncontrasting

confidence: 78%

“…CLIAs have the advantage in that they diagnose reactivity based on a reportable COI value. In our previous evaluation of the Abbott Architect IgG assay with a larger study population [ 1 ], an initial sensitivity of 45.9% within the first week of infection could be improved to 55.8% by using a lower, optimized COI value for reactivity. Other studies [ 24 ] have also suggested that a lower COI value for the diagnosis of reactive samples will improve the sensitivity of CLIAs in their cases with early infection.…”

Section: Discussionmentioning

confidence: 99%

“…For RT-PCR testing, our hospital molecular laboratory employs a duplex real-time RT-PCR that targets the N and E genes using a Qiagen EZ1 extraction system and Rotor Gene Q amplification system. The Abbott Architect SARS-CoV-2 IgG assay is a qualitative CLIA run on the ARCHITECT i2000 System, as described previously [ 1 ]. The stated cut-off index (COI) of the Architect IgG assay is 1.4.…”

Section: Methodsmentioning

confidence: 99%

“…The stated cut-off index (COI) of the Architect IgG assay is 1.4. In our hands [ 1 ], the Architect IgG assay had a CV of 3.4% (COI = 0.06) and 1.6% (COI = 8.6); assay specificity was 99.8%, and sensitivity of 96.7% for samples ≥14 days POS and 45.9% for samples <7 days. The Architect SARS-CoV-2 IgM antibody assay is also a CLIA that uses a similar principle to the Architect IgG assay, resulting in a signal (relative light unit) that is directly proportional to the amount of SARS-CoV-2 IgM titres and reflected in a COI; a COI of >1.0 is regarded as reactive.…”

Section: Methodsmentioning

confidence: 99%

“…Current novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) antibody immunoassays are mostly qualitative and include chemiluminescent immunoassays (CLIAs), enzyme-linked immunosorbent assays (ELISA), and lateral flow immunoassays (LFIA). We have previously evaluated the performance of CLIAs from Abbott [ 1 ] and Roche [ 2 ] and found them excellent. However, automated CLIAs require samples to be delivered to a central laboratory for analyses.…”

Section: Introductionmentioning

confidence: 99%

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Performance of two rapid point of care SARS-COV-2 antibody assays against laboratory-based automated chemiluminescent immunoassays for SARS-COV-2 IG-G, IG-M and total antibodies

Lau

Hoo

Liang

et al. 2021

Practical Laboratory Medicine

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Section: Discussioncontrasting

confidence: 78%

Section: Discussionmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Performance of two rapid point of care SARS-COV-2 antibody assays against laboratory-based automated chemiluminescent immunoassays for SARS-COV-2 IG-G, IG-M and total antibodies

Lau

Hoo

Liang

et al. 2021

Practical Laboratory Medicine

Self Cite

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Antibody tests for identification of current and past infection with SARS-CoV-2

Fox

Geppert

Dinnes

et al. 2022

Cochrane Database of Systematic Reviews

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Background The diagnostic challenges associated with the COVID‐19 pandemic resulted in rapid development of diagnostic test methods for detecting SARS‐CoV‐2 infection. Serology tests to detect the presence of antibodies to SARS‐CoV‐2 enable detection of past infection and may detect cases of SARS‐CoV‐2 infection that were missed by earlier diagnostic tests. Understanding the diagnostic accuracy of serology tests for SARS‐CoV‐2 infection may enable development of effective diagnostic and management pathways, inform public health management decisions and understanding of SARS‐CoV‐2 epidemiology. Objectives To assess the accuracy of antibody tests, firstly, to determine if a person presenting in the community, or in primary or secondary care has current SARS‐CoV‐2 infection according to time after onset of infection and, secondly, to determine if a person has previously been infected with SARS‐CoV‐2. Sources of heterogeneity investigated included: timing of test, test method, SARS‐CoV‐2 antigen used, test brand, and reference standard for non‐SARS‐CoV‐2 cases. Search methods The COVID‐19 Open Access Project living evidence database from the University of Bern (which includes daily updates from PubMed and Embase and preprints from medRxiv and bioRxiv) was searched on 30 September 2020. We included additional publications from the Evidence for Policy and Practice Information and Co‐ordinating Centre (EPPI‐Centre) ‘COVID‐19: Living map of the evidence’ and the Norwegian Institute of Public Health ’NIPH systematic and living map on COVID‐19 evidence’. We did not apply language restrictions. Selection criteria We included test accuracy studies of any design that evaluated commercially produced serology tests, targeting IgG, IgM, IgA alone, or in combination. Studies must have provided data for sensitivity, that could be allocated to a predefined time period after onset of symptoms, or after a positive RT‐PCR test. Small studies with fewer than 25 SARS‐CoV‐2 infection cases were excluded. We included any reference standard to define the presence or absence of SARS‐CoV‐2 (including reverse transcription polymerase chain reaction tests (RT‐PCR), clinical diagnostic criteria, and pre‐pandemic samples). Data collection and analysis We use standard screening procedures with three reviewers. Quality assessment (using the QUADAS‐2 tool) and numeric study results were extracted independently by two people. Other study characteristics were extracted by one reviewer and checked by a second. We present sensitivity and specificity with 95% confidence intervals (CIs) for each test and, for meta‐analysis, we fitted univariate random‐effects logistic regression models for sensitivity by eligible time period and for specificity by reference standard group. Heterogeneity was investigated by including indicator variables in the random‐effects logistic regression models. We tabulated result...

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Immunoglobin G/total antibody testing for SARS-CoV-2: A prospective cohort study of ambulatory patients and health care workers in two Belgian oncology units comparing three commercial tests

Dam

Huizing²,

Roelant

et al. 2021

European Journal of Cancer

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Background Coronavirus disease (COVID-19) is interfering heavily with the screening, diagnosis and treatment of cancer patients. Better knowledge of the seroprevalence and immune response after Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection in this population is important to manage them safely during the pandemic. Methods 922 cancer patients, 100 non-cancer patients and 94 healthcare workers (HCW) attending the Multidisciplinary Oncology Unit of Antwerp University Hospital from 24 th of March 2020 till 31 st of May 2020, and in the Oncology Unit of AZ Maria Middelares Hospital Gent from 13 th of April 2020 till 31 st of May 2020 participated. The Alinity® (A; Abbott) and Liaison® (D; Diasorin) commercially available assays were used to measure SARS-CoV-2 IgG, while total SARS-CoV-2 Ig was measured by Elecsys® (R; Roche) Results In the overall study population IgG/total SARS-CoV-2 antibodies were found in respectively 32/998 (3.2%), 68/1020(6.7%), 37/1010 (3.7%) and of individuals using the A, D or R test. Forty six out of 618 (7.4%) persons had a positive SARS-CoV-2 polymerase chain reaction (RT-PCR) test. Seroprevalence in cancer patients (A:2.2%, D:6.2%, R:3.0%), did not significantly differ from that in non-cancer patients (A:1.1%, D:5.6%, R:0.0%), but was lower than the HCW (A:13%, D:12%, R:12%; respectively Fisher’s exact test p=0.00001, p=0.046, p=0.0004). A positive SARS-CoV-2 RT-PCR was found in 6.8% of the cancer patients, 2.3% of the non-cancer patients and 28.1% of the HCW (Fisher’s exact test p=0.0004). Correlation between absolute value of the different Ig tests was poor in the cancer population. Dichotomizing a positive versus negative test result, the A and R test correlated well (kappa 0.82 p McNemar test=0.344), while A and D, and R and D did not (respectively kappa 0.49 and 0.57; result significantly different p McNemar test=<0.0001 for both). The rate of seroconversion (>75%) and median absolute antibody levels (A: 7.0 vs 4.7; D 74.0 vs 26.6, R: 16.34 vs 7.32; all > P Mann Whitney test=0.28) in cancer patients and HCW with a positive RT-PCR at least 7 days earlier did not show any differences. However, none (N=0/4) of the patients with hematological tumors had seroconversion and absolute antibody levels remained much lower compared to patients with solid tumors (R: 0.1 vs 37.6, p 0.003; D 4.1 vs 158, p 0.008) or HCW (all p<0.0001). Conclusion HCW were at high risk to be infected by SARS-CoV-2 during the first wave of the pandemic. Seroprevalence in cancer patients was low in the study period. Although Ig immune response in cancer patients with solid tumors does not differ from healthy volunteers, patients with hematological tumors have a very poor humoral immune response. This has to be taken into account in future vaccination programs in this population. SARS-C...

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Performance of an automated chemiluminescence SARS-CoV-2 IG-G assay

Cited by 21 publications

References 25 publications

Performance of two rapid point of care SARS-COV-2 antibody assays against laboratory-based automated chemiluminescent immunoassays for SARS-COV-2 IG-G, IG-M and total antibodies

Performance of two rapid point of care SARS-COV-2 antibody assays against laboratory-based automated chemiluminescent immunoassays for SARS-COV-2 IG-G, IG-M and total antibodies

Antibody tests for identification of current and past infection with SARS-CoV-2

Immunoglobin G/total antibody testing for SARS-CoV-2: A prospective cohort study of ambulatory patients and health care workers in two Belgian oncology units comparing three commercial tests

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