Serological diagnostic for SARS-CoV-2: an experimental External Quality Assessment Scheme

Area of Science:

• Clinical diagnostics
• Immunology
• Public health

Background:

• The SARS-CoV-2 pandemic necessitated rapid development of COVID-19 diagnostic tests.
• Medical laboratories developed in-house assays to meet high testing demands.
• Ensuring analytical procedure quality is crucial for patient safety.

Purpose of the Study:

• To evaluate an experimental External Quality Assessment (EQA) scheme for SARS-CoV-2 serological diagnosis.
• To assess the performance and agreement of laboratory results for COVID-19 antibody detection.

Main Methods:

• Collected and analyzed qualitative results from an EQA scheme for SARS-CoV-2 serology.
• Summarized 4,867 data sets to identify agreement percentages based on antibody type, results, and sample status.

Main Results:

• Higher agreement among laboratories was observed for total immunoglobulin (Ig) detection compared to single Ig (IgG, IgM, IgA) in positive samples.
• Significant divergence was found in IgM results for positive samples, with only 34.9% accuracy.
• Negative and specificity controls showed better overall agreement than positive samples.

Conclusions:

• Harmonization of SARS-CoV-2 serological test results is essential.
• Development of well-defined protocols aligned with ISO 15189 standards is recommended.
• Collaboration between laboratory professionals and IVD manufacturers is key to improving diagnostic accuracy and patient safety.