Relation between anti-Porphyromonas gingivalis antibody titers and HLA-DRB1 neutral alleles in individuals with rheumatoid arthritis

Abstract

Objective

This study aimed to determine the relation between titres of anti-Porphyromonas gingivalis (P. gingivalis) antibody and rheumatoid arthritis (RA) HLA-DRB1 susceptibility region associated with shared epitope (SE) using the Gregersen’s and de Vries’s classification methods.

Material and Methods

In this cross-sectional study, results of immunoglobulin G1 (IgG1) and immunoglobulin G2 (IgG2) anti-P. gingivalis antibodies, anti-citrullinated protein antibodies (ACPA), diagnosis for RA, and periodontal disease (PD), and a genetic study of the HLA DRB1 region were obtained from 50 patients with RA and 50 control individuals.

Results

Anti-P. gingivalis antibody levels and PD parameters were similar in control and RA groups. Anti-P. gingivalis antibodies were not associated with SE or ACPA. There was no association between ACPA and SE. However, de Vries’ classification in RA patients revealed an association between the HLA DRB1 neutral alleles and higher titres of anti-P. gingivalis antibodies as follows: IgG1 anti-P. gingivalis ≥ 1:400 (p = .039); IgG2 anti-P. gingivalis ≥ 1:400 with neutral/neutral genotype (N/N), being exclusive for RA (p = .008); and IgG2 anti-P. gingivalis ≥ 1:200 and N/N (p = .016).

Conclusions

Although no association was found between SE and anti-P. gingivalis antibodies; according to the de Vries’ classification, there was an existing association between HLA DRB1 neutral alleles, with high titres of IgG anti-P.gingivalis antibodies for RA, focussing on novel associations between P.gingivalis and RA.

Keywords:

• Porphyromonas gingivalis
• rheumatoid arthritis
• HLA DRB1
• shared epitope
• periodontal disease

Acknowledgements

The authors are grateful to Dr. Juan José Yunis Londoño for supporting the laboratory’s genetic methods, Dr. Victor Hidalgo for performing statistical analyses, Dr. Mauricio Rodriguez for supporting the methodological design and the rheumatologists, periodontists, and laboratory personnel who participated in the project.

Disclosure statement

The authors report no conflict of interest.

Additional information

Funding

This work was supported by the División de Investigación Sede Bogotá (DIB), Universidad Nacional de Colombia, under Grant [Hermes code: 20166]; Rheumatology and Immunology Department, Hospital Militar Central, Bogotá; Unit of Oral Basic Investigation, School of Dentistry, Universidad El Bosque, Bogotá; and Government Institute of Science, Technology and Innovation, Francisco José de Caldas—COLCIENCIAS under Grant [130854531734-2011].