Porphyromonas gingivalis infection in the oral cavity is associated with elevated galactose-deficient IgA1 and increased nephritis severity in IgA nephropathy.

BACKGROUND: The relationship between the major periodontal bacteria, Porphyromonas gingivalis, and the pathogenesis of IgA nephropathy (IgAN)-particularly with respect to galactose-deficient IgA1 (Gd-IgA1)-has not been fully elucidated. METHODS: Saliva samples from 30 IgAN patients and 44 patients with chronic kidney disease (CKD) were subjected to analysis of P. gingivalis status via polymerase chain reaction using a set of P. gingivalis-specific primers. The associations between P. gingivalis presence and clinical parameters, including plasma Gd-IgA1, were analyzed in each group. RESULTS: Compared with the CKD group, the IgAN group demonstrated significantly higher plasma Gd-IgA1 levels (p < 0.05). Compared with the P. gingivalis-negative subgroup, the P. gingivalis-positive subgroup exhibited significantly higher plasma Gd-IgA1 levels in both IgAN and CKD patients (p < 0.05). Additionally, among IgAN patients, the P. gingivalis-positive subgroup displayed significantly higher plasma Gd-IgA1 and urine protein levels, compared with the P. gingivalis-negative subgroup (p < 0.05). With respect to renal biopsy findings, the frequencies of segmental glomerulosclerosis and tubular atrophy/interstitial fibrosis were significantly greater in the P. gingivalis-positive subgroup than in the P. gingivalis-negative subgroup, according to the Oxford classification of IgAN (p < 0.05). CONCLUSION: Our findings suggest an association between the presence of P. gingivalis in the oral cavity and the pathogenesis of IgAN, mediated by increased levels of Gd-IgA1.

Dental caries status is associated with arteriosclerosis in patients on hemodialysis.

BACKGROUND: We previously found that worse dental caries status was associated with high pulse pressure among patients on hemodialysis, indicating that such patients might have arteriosclerosis. In this study, we used abdominal computed tomography to evaluate arteriosclerosis in patients on hemodialysis and investigated the association between arteriosclerosis and dental caries status. We also prospectively examined risk factors associated with 2-year prognosis. METHODS: The dental caries and periodontal disease statuses of 80 patients on hemodialysis were evaluated using the decayed, missing, or filled teeth (DMFT) index, and periodontal pocket depth, respectively. The aortic calcification index was semiquantitatively measured using computed tomography images of the abdominal aorta. Clinical data were also analyzed after all patients on hemodialysis provided written, informed consent to participate in the study. RESULTS: Regression analysis demonstrated a significant correlation between the DMFT and aortic calcification indexes. Multiple regression analysis showed that the DMFT index was significantly correlated with the aortic calcification index, following adjustment for age, sex, and dialysis period. Thirteen of the 80 patients died during the 2-year follow-up period; logistic regression analysis showed that mortality rate was significantly associated with the aortic calcification index, but not the DMFT index. However, periodontal pocket depth was not correlated with the aortic calcification index. CONCLUSION: These findings suggest that worse dental caries status could be associated with arteriosclerosis among patients on hemodialysis, which may indirectly affect the prognosis of arteriosclerosis in these patients.

Possible link between dental diseases and arteriosclerosis in patients on hemodialysis.

BACKGROUND: Patients on hemodialysis must undergo this procedure at a hospital three times weekly and might be unable to visit a dentist. In addition, dentists might hesitate to provide oral care because such patients tend to bleed because they are medicated with anticoagulants, are susceptible to bacterial infections, and might have unusual drug reactions. We postulated that patients on hemodialysis have worse oral status than healthy people, which in turn might predispose such patients to systemic complications. METHODS: We compared the status of dental caries and periodontal diseases among 80 patients on hemodialysis and 76 healthy individuals (controls) using the decayed, missing, or filled teeth (DMFT) index, total number of C4 teeth (destruction of the entire tooth crown), and periodontal pocket depth. Clinical data were analyzed after all patients on hemodialysis and controls provided written, informed consent to participate in the study. RESULTS: Total number of C4 teeth (p = 0.021), missing teeth (MT) index (p = 0.0302), and DMFT index score ≥ 24 (p = 0.017) were significantly higher in patients on hemodialysis than controls. Pulse pressure (p = 0.0042) and the prevalence of a history of heart disease such as angina pectoris and acute myocardial infarction (p = 0.029) were higher in patients on hemodialysis with higher (≥ 24) than lower (< 24) DMFT index scores. Periodontal pocket depth was not significantly different between these two groups. CONCLUSION: Worse status of dental caries is possibly associated with arteriosclerosis among patients on hemodialysis.

Presence of Streptococcus mutans strains harbouring the cnm gene correlates with dental caries status and IgA nephropathy conditions.

Streptococcus mutans is a major pathogen of human dental caries. Strains harbouring the cnm gene, which encodes Cnm, a collagen-binding protein, contribute to the development of several systemic diseases. In this study, we analysed S. mutans strains isolated from the oral cavity of immunoglobulin (Ig)A nephropathy (IgAN) patients to determine potential relationships between cnm and caries status as well as IgAN conditions. Saliva specimens were collected from 109 IgAN patients and the cnm status of isolated S. mutans strains was determined using PCR. In addition, the dental caries status (decayed, missing or filled teeth [DMFT] index) in patients who agreed to dental consultation (n = 49) was evaluated. The DMFT index and urinary protein levels in the cnm-positive group were significantly higher than those in the cnm-negative group (p < 0.05). Moreover, the urinary protein levels in the high DMFT (≥15) group were significantly higher than those in the low DMFT (<15) group (p < 0.05). Our results show that isolation of cnm-positive S. mutans strains from the oral cavity may be associated with urinary protein levels in IgAN patients, especially those with a high dental caries status.