A high-throughput Anti-SARS-CoV-2 IgG testing platform for COVID-19

Serology tests for SARS-CoV-2 antibodies are essential for tracking infection history and supporting diagnosis. Prior research has shown that these tests can detect past exposure and confirm current infection status. However, the accuracy of these tests remains a challenge, particularly in early stages of infection. No prior work had resolved how to balance sensitivity and specificity across different time points after symptom onset. This gap motivated the development of a new high-throughput immunoassay. The study addresses the need for reliable and scalable antibody detection methods. It builds on existing knowledge of IgG antibody behavior in viral infections. The absence of cross-reactivity data in prior studies highlights a key uncertainty. This paper contributes by evaluating a novel platform's performance in a clinical cohort.

The study aimed to assess the performance of a newly developed high-throughput immunoassay for detecting anti-SARS-CoV-2 IgG antibodies. Researchers focused on evaluating clinical agreement in both positive and negative samples. The specific problem addressed was the lack of validated high-throughput platforms with proven sensitivity and specificity. The motivation came from the need to scale up testing while maintaining accuracy. The study tested the assay's ability to detect antibodies at different time points after symptom onset. It also examined the test's resistance to interference from common blood components. No prior work had evaluated this specific immunoassay in a large clinical sample set. The goal was to provide evidence supporting the assay's use in widespread serology testing.

The study used clinical agreement studies involving 107 positive and 226 negative serum/plasma samples. Positive percent agreement was calculated for three time windows after symptom onset. Negative percent agreement was also measured to assess false-negative rates. The assay was tested for cross-reactivity with antibodies against other pathogens. Interference from hemoglobin, bilirubin, and EDTA was evaluated. Sample collection followed established protocols for SARS-CoV-2 antibody testing. Statistical analysis included confidence intervals to quantify uncertainty. The immunoassay's high-throughput design enabled rapid processing of large sample volumes.

Positive percent agreement was 46.15 % for samples collected within 0-7 days of symptom onset. It increased to 61.54 % for 8-14 days and 97.53 % for ≥15 days. Negative percent agreement reached 98.23 % across all tested samples. No cross-reactivity was observed with antibodies against HIV, HAV, HBV, and others. Hemoglobin, bilirubin, and EDTA did not interfere with the assay's performance. The assay demonstrated high specificity and sensitivity in the later stages of infection. These findings suggest the platform is suitable for large-scale serology testing. The results support the use of this immunoassay in clinical settings.

The study found that the immunoassay has high sensitivity and specificity for anti-SARS-CoV-2 IgG detection. It performs best when samples are collected ≥15 days after symptom onset. The assay showed no cross-reactivity with other common pathogens. It is resistant to interference from hemoglobin, bilirubin, and EDTA. These findings align with the authors' goal of developing a reliable high-throughput platform. The results support the use of this test in large-scale serology programs. The authors propose that this assay can help expand testing capacity without sacrificing accuracy. The study confirms the platform's potential for widespread application in clinical diagnostics.