Immunoglobulin G genetic variation can confound assessment of antibody levels via altered binding to detection reagents

Purcell, RA; Aurelia, LC; Esterbauer, R; Allen, LF; Bond, KA; Williamson, DA; Trevillyan, JM; Trubiano, JA; Juno, JJ; Wheatley, AK; Davenport, MP; Nguyen, TH; Kedzierska, K; Kent, SJ; Selva, KJ; Chung, AW

Author(s): Purcell, RA; Aurelia, LC; Esterbauer, R; Allen, LF; Bond, KA; Williamson, DA; Trevillyan, JM; Trubiano, JA; Juno, JJ; Wheatley, AK; Davenport, MP; Nguyen, TH; Kedzierska, K; Kent, SJ; Selva, KJ; Chung, AW;
Details: Publication Year 2024,Volume 13,Issue #3,Page e1494
Journal Title: Clinical & Translational Immunology
Publication Type: Research article
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.
Publisher: Wiley
Keywords: IgG; allotype; anti‐immunoglobulin; polymorphisms; reproducibility; serology
Department(s): Infectious Diseases
Publisher's Version: https://doi.org/10.1002/cti2.1494
Open Access at Publisher's Site: https://doi.org/10.1002/cti2.1494
Terms of Use/Rights Notice: Refer to copyright notice on published article.

Creation Date: 2024-04-16 01:10:03

Last Modified: 2024-04-16 01:23:13