Atopic Biomarker Changes after Exposure to Porphyromonas gingivalis Lipopolysaccharide: A Small Experimental Study in Wistar Rat

Background: IgE and IgG4 are implicated in atopic development and clinically utilized as major biomarkers. Atopic responses following certain pathogens such as Porphyromonas gingivalis is currently an area of interest for further research. Purpose: The aim of this study is to measure the level of IgE, IgG4, and IgG4/IgE ratio periodically after exposure of periodontal pathogen Porphyromonas gingivalis (Pg) lipopolysaccharide (LPS). Methods: We used 16 wistar rats (Rattus norvegicus) randomly subdivided into 4 groups, group 1 were injected by placebo, group 2 by LPS Pg 0.3 μg/mL, group 3 by LPS Pg 1 μg/mL, and group 4 by LPS Pg 3 μg/mL. Sera from both groups were taken from retro-orbital plexus before and after exposure. Results: Level of IgE and IgG4 increased significantly following exposure of LPS Pg at day-4 and day-11. Greater increase of IgE rather than IgG4 contributes to rapid decline of IgG4/IgE ratio, detected in the peripheral blood at day-4 and day-11. Conclusion: Modulation of atopic responses following exposure to LPS Pg is reflected by decrease in IgG4/IgE ratio that accompanies an increase of IgE. Keywords: allergic diseases; atopic inflammatory pathway; immunoglobulin; periodontal pathogen; Porphyromonas gingivalis LPS Clinical significance: Porphyromonas gingivalis, a keystone pathogen during periodontal disease, may have a tendency to disrupt atopic biomarkers.