@article{b75ffbbe672d49e59307856817389ed2,
title = "Immunoglobulin G genetic variation can confound assessment of antibody levels via altered binding to detection reagents",
abstract = "Objectives: Amino acid variations across more than 30 immunoglobulin (Ig) allotypes may introduce structural changes that influence recognition by anti-Ig detection reagents, consequently confounding interpretation of antibody responses, particularly in genetically diverse cohorts. Here, we assessed a panel of commercial monoclonal anti-IgG1 clones for capacity to universally recognise two dominant IgG1 haplotypes (G1m-1,3 and G1m1,17). Methods: Four commercial monoclonal anti-human IgG1 clones were assessed via ELISAs and multiplex bead-based assays for their ability to bind G1m-1,3 and G1m1,17 IgG1 variants. Detection antibodies were validated against monoclonal IgG1 allotype standards and tested for capacity to recognise antigen-specific plasma IgG1 from G1m-1,3 and G1m1,17 homozygous and heterozygous SARS-CoV-2 BNT162b2 vaccinated (n = 28) and COVID-19 convalescent (n = 44) individuals. An Fc-specific pan-IgG detection antibody corroborated differences between hinge- and Fc-specific anti-IgG1 responses. Results: Hinge-specific anti-IgG1 clone 4E3 preferentially bound G1m1,17 compared to G1m-1,3 IgG1. Consequently, SARS-CoV-2 Spike-specific IgG1 levels detected in G1m1,17/G1m1,17 BNT162b2 vaccinees appeared 9- to 17-fold higher than in G1m-1,3/G1m-1,3 vaccinees. Fc-specific IgG1 and pan-IgG detection antibodies equivalently bound G1m-1,3 and G1m1,17 IgG1 variants, and detected comparable Spike-specific IgG1 levels between haplotypes. IgG1 responses against other human coronaviruses and influenza were similarly poorly detected by 4E3 anti-IgG1 in G1m-1,3/G1m-1,3 subjects. Conclusion: Anti-IgG1 clone 4E3 confounds assessment of antibody responses in clinical cohorts owing to bias towards detection of G1m1,17 IgG1 variants. Validation of anti-Ig clones should include evaluation of binding to relevant antibody variants, particularly as the role of immunogenetics upon humoral immunity is increasingly explored in diverse populations.",
keywords = "allotype, anti-immunoglobulin, IgG, polymorphisms, reproducibility, serology",
author = "Purcell, \{Ruth A.\} and Aurelia, \{L. Carissa\} and Robyn Esterbauer and Allen, \{Lilith F.\} and Bond, \{Katherine A.\} and Williamson, \{Deborah A.\} and Trevillyan, \{Janine M.\} and Trubiano, \{Jason A.\} and Juno, \{Jennifer J.\} and Wheatley, \{Adam K.\} and Davenport, \{Miles P.\} and Nguyen, \{Thi H.O.\} and Katherine Kedzierska and Kent, \{Stephen J.\} and Selva, \{Kevin John\} and Chung, \{Amy W.\}",
note = "Funding Information: This study was supported by a Medical Research Future Fund (MRFF) GNT \#2016062 to JAT, JAJ, AKW, MPD, THON, KK, SJK and AWC, and a National Health and Medical Research Council (NHMRC) Investigator grant \#2008092 to AWC. JAJ, AKW, MPD, THON, KK and SJK are also supported by NHMRC Investigator grants. We thank P Ramanathan, E Haycroft, T Amarasena, K Wragg, P Konstandopoulos, G Gare, K Field, H Kelly (University of Melbourne), G Gibney and F James (Austin Health) for their outstanding technical assistance. Open access publishing was facilitated by The University of Melbourne, as part of the Wiley ‐ The University of Melbourne agreement via the Council of Australian University Librarians. Funding Information: This study was supported by a Medical Research Future Fund (MRFF) GNT \#2016062 to JAT, JAJ, AKW, MPD, THON, KK, SJK and AWC, and a National Health and Medical Research Council (NHMRC) Investigator grant \#2008092 to AWC. JAJ, AKW, MPD, THON, KK and SJK are also supported by NHMRC Investigator grants. We thank P Ramanathan, E Haycroft, T Amarasena, K Wragg, P Konstandopoulos, G Gare, K Field, H Kelly (University of Melbourne), G Gibney and F James (Austin Health) for their outstanding technical assistance. Open access publishing was facilitated by The University of Melbourne, as part of the Wiley - The University of Melbourne agreement via the Council of Australian University Librarians. Publisher Copyright: {\textcopyright} 2024 The Authors. Clinical \& Translational Immunology published by John Wiley \& Sons Australia, Ltd on behalf of Australian and New Zealand Society for Immunology, Inc.",
year = "2024",
doi = "10.1002/cti2.1494",
language = "English",
volume = "13",
journal = "Clinical \& Translational Immunology",
issn = "2050-0068",
publisher = "John Wiley \& Sons",
number = "3",
}
