Evidence map›Paper›PMID 40454936›Full record

ArticleMicrobiology spectrum2025

Comparison of NADAL COVID IgG/IgM rapid test and DiaSorin Liaison SARS-CoV-2 S1/S2 IgG assay across different blood sources and substrates.

Harika Dasari, Claude Bourassa, Christian Renaud, Cécile Tremblay, Francine M Ducharme

Abstract readComparative Study
In one paragraph

Article in Microbiology spectrum, 2025. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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0citing papers in PubMed
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1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

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Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.

3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

5 authors.

Harika DasariClinical Research and Knowledge Transfer Unit on Childhood Asthma, Centre Hospitalier Universitaire Sainte-Justine, Montreal, Québec, Canada.ORCID 0000-0002-0979-0956
Claude BourassaOptilab Montréal-Sainte-Justine, Departments of Pediatrics and Microbiology, Infectiology and Immunology Centre, Hospitalier Universitaire Sainte-Justine, Montreal, Québec, Canada.
Christian RenaudOptilab Montréal-Sainte-Justine, Departments of Pediatrics and Microbiology, Infectiology and Immunology Centre, Hospitalier Universitaire Sainte-Justine, Montreal, Québec, Canada.
Cécile TremblayMicrobiology and Infectious Disease, Centre Universitaire de santé de Montréal (CHUM), University of Montreal, Montreal, Québec, Canada.
Francine M DucharmeClinical Research and Knowledge Transfer Unit on Childhood Asthma, Centre Hospitalier Universitaire Sainte-Justine, Montreal, Québec, Canada.

Funding

CIHR 447317
6 · The paper itself

Abstract

The NADAL COVID-19 IgG/IgM (NADAL) assay, approved for rapid testing on serum or plasma, had not been approved nor tested as a point-of-care test on capillary blood. The study aim was to evaluate the performance of NADAL compared to that of the DiaSorin Liaison SARS-CoV-2 S1/S2 IgG (DiaSorin) assay (gold standard). We conducted two cross-sectional studies in participants aged ≥2 years, in whom different blood substrates (whole blood vs serum) and sources (venous vs capillary) were sampled. The co-primary endpoints were agreement in IgG detection between NADAL on venous serum and whole capillary blood vs DiaSorin on venous serum. Among 128 participants, 23.2% had a positive DiaSorin IgG assay. The NADAL IgG on venous serum exhibited near-perfect agreement (κ = 0.91) and high accuracy (0.94, 95% CI: 0.87-1.00), with a sensitivity of 0.88 and perfect specificity compared to DiaSorin; NADAL IgG on whole capillary blood exhibited moderate agreement (κ = 0.77) and accuracy (0.84, 95% CI: 0.73-0.95), with a sensitivity of 0.68 and perfect specificity. As for secondary outcomes, when the two assays were compared within the same source (venous or capillary) but with different substrates (NADAL on whole blood vs DiaSorin on serum), strong agreement and high accuracy were observed. Within-test DiaSorin IgG assay on capillary vs venous serum showed near-perfect agreement and high accuracy. Within-test NADAL IgG assays on whole capillary blood vs capillary or venous serum demonstrated high accuracy. In conclusion, NADAL on venous serum exhibited near-perfect agreement and high accuracy with DiaSorin on venous serum but lower between-test performance on different blood substrates. IMPORTANCE: Accurate serological assays are essential for assessing population immunity levels and identifying vulnerable subgroups with lower immunity on which to focus vaccination efforts. Although rapid tests may offer the possibility of easy point-of-care testing on whole capillary blood for these purposes, they may not be as robust as other assays when used on different blood substrates or sources than those in which they were approved. The observed variability in test performance across different substrates and blood sources highlights the importance of pretesting assays under the specific conditions in which they would be used to ensure optimal interpretation of the immune status in the community.

Indexed as

Antibodies, ViralCOVID-19COVID-19 Serological TestingImmunoglobulin GImmunoglobulin MSARS-CoV-2AdultAgedCross-Sectional StudiesFemaleHumansMaleMiddle AgedPoint-of-Care TestingSensitivity and SpecificityAntibodies, ViralImmunoglobulin GImmunoglobulin Mdiagnostic accuracyNADAL COVID-19 Testpoint-of-care testingSARS-CoV-2 IgG/IgM serologysensitivity and specificitywhole capillary blood

Identifiers

PMID40454936
PMCPMC12211023

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.