High similarity of IgG antibody profiles in blood and saliva opens opportunities for saliva based serology

Abstract

Saliva based diagnostics is a rapidly evolving field due to the large diagnostic potential and simple sample collection. Currently only few individual molecules were investigated for their diagnostic capabilities in saliva. A systematic comparison of IgG antibody profiles in saliva and plasma is still missing in scientific literature. Our hypothesis is that IgG profiles in plasma and saliva are highly similar for each individual. As a consequence, one could implement practically any plasma based IgG assay (classical serology) as saliva based assay. In other words, the IgG antibodies found in blood are also accessible from saliva. We confirm our hypothesis by comparing IgG reactivities towards protein and peptide antigens. We isolated saliva IgG with high purity and demonstrate that plasma IgG reactivities (classical serology) can be inferred from saliva. As a showcase we perform Hepatitis B virus antibody (plasma-)titer determination from saliva. Additionally we show that plasma and saliva IgG profiles of 20 individuals are highly similar for 256 peptide antigens and match (unsupervised) with high probabilities. Finally, we argue for generalisation to the complete IgG antibody profile. The presented findings could contribute greatly to the development of saliva based diagnostic methods of numerous antibody based tests.

ELISA detection of SARS-CoV-2 antibodies in saliva

“…Although serum is the typical sample type for detecting developed antibodies against many infectious diseases, dried blood spots 7,8 and saliva samples [9][10][11] have also been used successfully. Saliva samples are particularly attractive given the ease and non-invasiveness of sampling, allowing for potential self-collection and substantial scaling of testing.…”

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

“…Hettegger et al demonstrated that IgG profiles in plasma and saliva are highly similar for each individual and found the anti-HBV IgG antibody from saliva ( Hettegger et al, 2019 ). We therefore tested saliva and serum from a COVID-19 patient.…”

Stress/Immune Biomarkers in Saliva among Children with ADHD Status

“…Salivary IgG concentrations were quantitatively determined by the ELISA method using the ELISA Kit E0544h for research use only (RUO) (EIAab, Wuhan, China). The standard curve ranged from 0 to 5000 pg/mL, the intra-assay variability coefficient was <4.4%, and the inter-assay variability was <7.8%, respectively (r 2 = 0.999, p < 0.001) [ 36 , 37 ].…”