POS1429 ORAL DYSBIOSIS REFLECTS THE IMMUNOLOGICAL ALTERATION OF RA REGARDING TO HLA DRB1*SE, ACPA AND CIGARETTE SMOKING: NAGASAKI ISLAND STUDY

Background: Anti-citrullinated protein antibody (ACPA) production is observed in several organs even prior to the onset of rheumatoid arthritis (RA), and oral mucosa considered be one important tissues. Saliva reflect microbiota(oralMB) including periodontal disease. A gene-environment interaction between cigarette smoking shared epitope genes HLA-DRB1*shared (SE) provides a high risk ACPA-positive RA. However, HLA-DRB1*SE, ACPA, oralMB RA patients remains elucidated. Objectives: We investigated that difference among healthy subjects(HS) regarding HLA-DRB1*SE smoking. Methods: The Nagasaki Island Study, which had started 2014 collaborating with Goto City, Prefecture, Japan, intended for research preclinical stage RA, HLA genotype screening, lifestyle habit. Both blood salivary samples were obtained from 1422 subjects out 4276 participants this study 2016 2018. ACPA positivity was 1.7 % total subjects. At point, we selected 291 subjects, who positive non-RA HS(n=22) (n=33, 11 22 negative, respectively) as case, age gender matched negative HS (n=236) control. In current smoker n=1(3.0%) ever n=8(24.2%). HS, n=29(11.2%) n=55(21.3%). measured by ELISA, genotyping quantified next-generation sequencing (Ref.1). operational taxonomic unit (OTU) analysis using 16S rRNA gene performed. richness microbial diversity within subject (α-diversity) scaled via Shannon entropy. dissimilarity community composition calculated Bray-Curtis distance scale, differences groups (β-diversity) tested permutational multivariate variance (PERMANOVA). addition, UniFrac consideration on phylogenetic tree Results: Median 71 y.o., Female 58.4 %. Among not α-diversity but β-diversity statistically smaller significantly (p=0.022). there no decrease HLA-DRB1*SE-positive groups, group, group. When compared stratified presence or absence three factors (RA, HLA-DRB1*SE), group tended have lowest (Figure 1 lower right). did show tendency (p=0.29). Conclusion: than HS. Furthermore, showed HLA-DRB1*SE. Our suggested dysbiosis may immunological status Because small number patients, stratification history difficult. Further examination needed clarify microbiome. References: [1]Kawaguchi S, et al. Methods Mol Biol 2018;1802: 22. Disclosure Interests: None declared