A6.8 Elevated antibody levels to porphyromonas gingivalis detected in rheumatoid arthritis patients with a specific anti-citrullinated protein/peptide antibody profile

The Immune System Response to Porphyromonas gingivalis in Neurological Diseases

Previous studies have reported an association between oral microbial dysbiosis and the development and progression of pathologies in the central nervous system. Porphyromonas gingivalis (Pg), the keystone pathogen of the oral cavity, can induce a systemic antibody response measured in patients' sera using enzyme-linked immunosorbent assays. The present case-control study quantified the immune system's response to Pg abundance in the oral cavities of patients affected by different central nervous system pathologies. The study cohort included 87 participants: 23 healthy controls (HC), 17 patients with an acute neurological condition (N-AC), 19 patients with a chronic neurological condition (N-CH), and 28 patients with neurodegenerative disease (N-DEG). The results showed that the Pg abundance in the oral cavity was higher in the N-DEG patients than in the HC (p = 0.0001) and N-AC patients (p = 0.01). In addition, the Pg abundance was higher in the N-CH patients than the HCs (p = 0.005). Only the N-CH patients had more serum anti-Pg antibodies than the HC (p = 0.012). The inadequate response of the immune system of the N-DEG group in producing anti-Pg antibodies was also clearly indicated by an analysis of the ratio between the anti-Pg antibodies quantity and the Pg abundance. Indeed, this ratio was significantly lower between the N-DEG group than all other groups (p = 0.0001, p = 0.002, and p = 0.03 for HC, N-AC, and N-CH, respectively). The immune system's response to Pg abundance in the oral cavity showed a stepwise model: the response diminished progressively from the patients affected with an acute condition to the patients suffering from chronic nervous system disorders and finally to the patients affected by neurodegenerative diseases.

Porphyromonas gingivalis: major periodontopathic pathogen overview

Porphyromonas gingivalis is a Gram-negative oral anaerobe that is involved in the pathogenesis of periodontitis and is a member of more than 500 bacterial species that live in the oral cavity. This anaerobic bacterium is a natural member of the oral microbiome, yet it can become highly destructive (termed pathobiont) and proliferate to high cell numbers in periodontal lesions: this is attributed to its arsenal of specialized virulence factors. The purpose of this review is to provide an overview of one of the main periodontal pathogens—Porphyromonas gingivalis. This bacterium, along with Treponema denticola and Tannerella forsythia, constitute the “red complex,” a prototype polybacterial pathogenic consortium in periodontitis. This review outlines Porphyromonas gingivalis structure, its metabolism, its ability to colonize the epithelial cells, and its influence upon the host immunity.