Heterogeneous Systemic IgG Responses to Porphyromonas gingivalis Gingipains in Advanced Periodontitis

Area of Science:

• Periodontology
• Immunology
• Microbiology

Background:

• Periodontitis is a chronic inflammatory disease affecting the gums and supporting bone.
• Porphyromonas gingivalis is a key pathogen implicated in periodontitis.
• Gingipains (RgpB and Kgp) are virulence factors produced by P. gingivalis.

Purpose of the Study:

• To evaluate serum IgG responses against P. gingivalis gingipains RgpB and Kgp in patients with stage III and IV periodontitis.
• To examine associations between these IgG responses and clinical periodontal parameters.

Main Methods:

• Cross-sectional study of 42 patients with stage III and IV periodontitis.
• Clinical parameters including bleeding on probing (BoP%), probing pocket depth (PPD), and tooth loss were assessed.
• Serum IgG levels against recombinant RgpB and Kgp were quantified using ELISA.

Main Results:

• All participants showed measurable serum IgG against RgpB and Kgp, with significant heterogeneity.
• Higher anti-RgpB IgG levels were observed in Stage IV compared to Stage III periodontitis.
• Anti-RgpB IgG correlated positively with age and inversely with the number of teeth.

Conclusions:

• Serum IgG responses to RgpB and Kgp are heterogeneous in advanced periodontitis.
• Anti-RgpB IgG is associated with age and tooth loss, reflecting cumulative disease exposure.
• Gingipain-specific IgG may indicate disease burden rather than current inflammatory activity.