Background: Leukocyte Fc receptors for immunoglobulin G (FcgammaR) play a major role in the handling of immune complexes and pathogens in systemic lupus erythematosus (SLE) and periodontitis. Both diseases have been shown to be partly influenced by genetic components including FcgammaR genotype. The aim of this study was therefore to evaluate whether FcgammaR gene polymorphisms are associated with periodontitis risk in SLE patients.
Methods: The study subjects consisted of 42 SLE patients with periodontitis (SLE/P), 18 SLE patients without periodontitis (SLE/H), 42 healthy subjects with periodontitis (H/P), and 42 healthy subjects without periodontitis (H/H), who were all unrelated Japanese non-smokers. Genomic DNA was isolated from peripheral blood, and FcgammaR genotypes for 3 biallelic polymorphisms (FcgammaRIIa-R131/H131, FcgammaRIIIa-158V/158F, FcgammaRIIIb-NA1/NA2) were determined by allele-specific polymerase chain reactions.
Results: The SLE/P group was found to have more mild levels of periodontal destruction than the H/P group (P < 0.01). There was a significant difference in the distribution of FcgammaRIIa genotypes between SLE/P and H/H groups (P = 0.004). A significant overrepresentation of the FcgammaRIIa-R131 allele was found in the SLE/P group compared to the H/H group (SLE/P versus H/H: odds ratio [OR] 3.13, 95% confidence interval [CI] 1.46-6.77, P = 0.0013). Furthermore, the prevalence of periodontitis was found to be 70% in SLE patients. The FcgammaRIIa-R131 allele was also found to be overrepresented in the SLE/P group compared to the SLE/H group (SLE/P versus SLE/H: OR 3.40, 95% CI 1.18-10.25, P = 0.011).
Conclusion: These results show the FcgammaRIIa-R131 allele to be associated with periodontitis risk in SLE patients.