Relationship between IgA Nephropathy and Porphyromonas gingivalis; Red Complex of Periodontopathic Bacterial Species

Cigarette smoking and progression of kidney dysfunction: a longitudinal cohort study

INTRODUCTION

Cigarette smoking is one of the most important life-modifiable risk factors for CVD events. The effect on CKD progression caused by smoking remained uncertain, while the effect on CVD had been established.

METHOD

The study population included participants from the specific health check and specific health guidance, an annual health check-up for all inhabitants of Japan who were aged between 40 and 74 years. 149,260 subjects (male, 37.1%; female, 62.9%) were included in this analysis.

RESULTS

The relationship between smoking status along with new-onset proteinuria and eGFR deterioration more than 15 mL/min/1.73 m2 was examined. Median observation periods were 1427 days [738, 1813] in males and 1437 days [729, 1816] in females. In male participants, the strongest factor upon kidney dysfunction was new-onset proteinuria (1.41 [1.31 1.51], P < 0.001). The second strongest factor on kidney deterioration was smoking (1.24 [1.16 1.31], P < 0.001). In female participants, strongest factor upon kidney dysfunction was smoking (1.27 [1.16-1.39], P < 0.001). The second strongest factor on kidney deterioration was new-onset proteinuria (1.26 [1.17 1.36], P < 0.001). To reveal the relationship of effects from new-onset proteinuria and smoking on the kidney function, the participants were divided into four groups with and without new-onset proteinuria and smoking. The group with both proteinuria and smoking had significantly worst renal prognosis (P for trend < 0.001).

CONCLUSION

Large longitudinal observation study revealed smoking has an evil effect on the progression of CKD. This evil effect could be observed in CKD patients with proteinuria as well as in general population without new-onset proteinuria.

Association between oral microbiome and five types of respiratory infections: a two-sample Mendelian randomization study in east Asian population

Objective

To explore the causal relationship between the oral microbiome and specific respiratory infections including tonsillitis, chronic sinusitis, bronchiectasis, bronchitis, and pneumonia, assessing the impact of genetic variations associated with the oral microbiome.

Methods

Mendelian randomization was used to analyze genetic variations, leveraging data from genome-wide association studies in an East Asian cohort to identify connections between specific oral microbiota and respiratory infections.

Results

Our analysis revealed that Prevotella, Streptococcus, Fusobacterium, Pauljensenia, and Capnocytophaga play crucial roles in influencing respiratory infections. Prevotella is associated with both promoting bronchitis and inhibiting pneumonia and tonsillitis, with a mixed effect on chronic sinusitis. Streptococcus and Fusobacterium show varied impacts on respiratory diseases, with Fusobacterium promoting chronic sinusitis, bronchiectasis, and bronchitis. Conversely, Pauljensenia and Capnocytophaga are linked to reduced bronchitis and tonsillitis, and inhibited pneumonia and bronchitis, respectively.

Discussion

These findings underscore the significant impact of the oral microbiome on respiratory health, suggesting potential strategies for disease prevention and management through microbiome targeting. The study highlights the complexity of microbial influences on respiratory infections and the importance of further research to elucidate these relationships.

Influence of IgA nephropathy on the progression of pulpitis and apical periodontitis in HIGA mice

OBJECTIVES

Immunoglobulin (Ig)A nephropathy has been associated with oral infections such as periodontitis, but its pathogenesis is not fully understood; no treatments exist. This study analyzes the influence of IgA nephropathy, an autoimmune disease, on the pathogenesis of pulpitis and apical periodontitis.

METHODS

Two groups of mice were used in pulp infection experiments: high serum IgA nephropathy model mice (HIGA) and control mice (BALB/c). Histologic analyses of the pulp and apical periodontal tissues were performed on days 3, 5, 7, 14, and 28 following oral bacterial infection. The dynamics of odontoblasts, apoptotic cells, and IgA expression were analyzed using anti-Nestin, TUNEL, and anti-IgA staining, respectively.

RESULTS

Inflammatory cells infiltrated the exposed pulp at day three in both groups and by 14 days, these cells had infiltrated from the pulp to the apical periodontal tissue. The area of necrotic pulp tissue increased significantly in the control group at seven days. Odontoblasts decreased from day three onwards and disappeared by 28 days in both groups. The number of apoptotic cells in the pulp and apical periodontal tissues was significantly higher in the experimental group at day 28. The experimental group exhibited a significant increase in IgA production in the pulp after 14 days. Bone resorption in the apical periodontal tissue was significantly decreased in the experimental group at day 28.

CONCLUSIONS

The results of this study suggest that IgA nephropathy may modulate the inflammatory response and sustain long-term biological defense responses in pulpitis and apical periodontitis in HIGA mice.

The complement system as a key modulator of the oral microbiome in health and disease

In this review, we address the interplay between the complement system and host microbiomes in health and disease, focussing on oral bacteria known to contribute to homeostasis or to promote dysbiosis associated with dental caries and periodontal diseases. Host proteins modulating complement activities in the oral environment and expression profiles of complement proteins in oral tissues were described. In addition, we highlight a sub-set of bacterial proteins involved in complement evasion and/or dysregulation previously characterized in pathogenic species (or strains), but further conserved among prototypical commensal species of the oral microbiome. Potential roles of these proteins in host-microbiome homeostasis and in the emergence of commensal strain lineages with increased virulence were also addressed. Finally, we provide examples of how commensal bacteria might exploit the complement system in competitive or cooperative interactions within the complex microbial communities of oral biofilms. These issues highlight the need for studies investigating the effects of the complement system on bacterial behaviour and competitiveness during their complex interactions within oral and extra-oral host sites.

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.

Association between gingival bleeding and hematuria as biomarkers of periodontitis and renal disease: a review

Gingival bleeding is a common complaint and symptom in patients with periodontitis. In clinics, gingival bleeding is regarded as an important sign of gingival inflammation, which is also of great significance in predicting the activity of periodontitis. Existing research has indicated that periodontitis has an impact on distant sites, such as the kidney. Hematuria is the principal feature of glomerular disease, which can reflect the degree and condition of glomerular inflammation. Previous studies have revealed an association between periodontal diseases with renal diseases, so a study is necessary to discuss their representative signs of them. For the moment, there are no reports that are concerned about the correlation between gingival bleeding with hematuria. The main point of this text is to review the potential association between gingival bleeding with hematuria, reveal their underlying mechanisms, and provide instructions for the therapy of periodontitis and glomerular diseases.

Porphyromonas gingivalis Gingipains Destroy the Vascular Barrier and Reduce CD99 and CD99L2 Expression To Regulate Transendothelial Migration

Porphyromonas gingivalis is an important periodontal pathogen that can cause vascular injury and invade local tissues through the blood circulation, and its ability to evade leukocyte killing is critical to its distal colonization and survival. Transendothelial migration (TEM) is a series of that enable leukocytes to squeeze through endothelial barriers and migrate into local tissues to perform immune functions. Several studies have shown that P. gingivalis-mediated endothelial damage initiates a series of proinflammatory signals that promote leukocyte adhesion. However, whether P. gingivalis is involved in TEM and thus influences immune cell recruitment remains unknown. In our study, we found that P. gingivalis gingipains could increase vascular permeability and promote Escherichia coli penetration by downregulating platelet/endothelial cell adhesion molecule 1 (PECAM-1) expression in vitro. Furthermore, we demonstrated that although P. gingivalis infection promoted monocyte adhesion, the TEM capacity of monocytes was substantially impaired, which might be due to the reduced CD99 and CD99L2 expression on gingipain-stimulated endothelial cells and leukocytes. Mechanistically, gingipains mediate CD99 and CD99L2 downregulation, possibly through the inhibition of the phosphoinositide 3-kinase (PI3K)/Akt pathway. In addition, our in vivo model confirmed the role of P. gingivalis in promoting vascular permeability and bacterial colonization in the liver, kidney, spleen, and lung and in downregulating PECAM-1, CD99, and CD99L2 expression in endothelial cells and leukocytes. IMPORTANCE P. gingivalis is associated with a variety of systemic diseases and colonizes in distal locations in the body. Here, we found that P. gingivalis gingipains degrade PECAM-1 to promote bacterial penetration while simultaneously reducing leukocyte TEM capacity. A similar phenomenon was also observed in a mouse model. These findings established P. gingivalis gingipains as the key virulence factor in modulating the permeability of the vascular barrier and TEM processes, which may provide a new rationale for the distal colonization of P. gingivalis and its associated systemic diseases.

Editorial for the IJMS Special Issue on "Infection and the Kidney"

The coronavirus disease (COVID-19) pandemic has highlighted the close relationship between infection and kidney injury [...].

cnm-positive Streptococcus mutans is associated with galactose-deficient IgA in patients with IgA nephropathy

The presence of Streptococcus mutans expressing Cnm protein encoded by cnm (cnm-positive S. mutans) in the oral cavity is associated with immunoglobulin A (IgA) nephropathy (IgAN). However, the precise mechanism by which cnm-positive S. mutans is involved in the pathogenesis of IgAN remains unclear. The present study evaluated glomerular galactose-deficient IgA1 (Gd-IgA1) to clarify the association between the presence of cnm-positive S. mutans and glomerular Gd-IgA1 in patients with IgAN. The presence of S. mutans and cnm-positive S. mutans was evaluated by polymerase chain reaction in saliva specimens from 74 patients with IgAN or IgA vasculitis. Immunofluorescent staining of IgA and Gd-IgA1 using KM55 antibody in clinical glomerular tissues was then performed. There was no significant association between the glomerular staining intensity of IgA and the positive rate of S. mutans. However, there was a significant association between the glomerular staining intensity of IgA and the positive rate of cnm-positive S. mutans (P < 0.05). There was also a significant association between the glomerular staining intensity of Gd-IgA1 (KM55) and the positive rate of cnm-positive S. mutans (P < 0.05). The glomerular staining intensity of Gd-IgA1 (KM55) was not associated with the positive rate of S. mutans. These results suggest that cnm-positive S. mutans in the oral cavity is associated with the pathogenesis of Gd-IgA1 in patients with IgAN.

[Research Progress in the Correlation Between Oral Microbiota and Chronic Kidney Disease]

Chronic kidney disease (CKD), one of the common clinical urological diseases, is increasingly more prevalent in recent years and has emerged as a major concern of public health around the globe. The continuous recurrence of CKD caused by renal function impairment leads eventually to irreversible renal failure and severe systemic complications, which causes severe negative impact on the quality of life of the patient. As an essential component of human microbiome, oral microbiota plays a major role in maintaining health, and there has been research suggesting close association between oral dysbiosis and CKD. It is therefore of great clinical significance to understand the correlation between CKD and oral microbiota. Herein, we reviewed the characteristics of oral microbiota of CKD patients, the possible mechanisms of oral microbiota's involvement in the pathogenesis and development of CKD, and the latest research findings on oral dysbiosis and CKD, with a view to finding new approaches to early prevention and control of CKD through oral microbial targets.

Transcriptomic analysis reveals the potential crosstalk genes and immune relationship between IgA nephropathy and periodontitis

Background

It is well known that periodontitis has an important impact on systemic diseases. The aim of this study was to investigate potential crosstalk genes, pathways and immune cells between periodontitis and IgA nephropathy (IgAN).

Methods

We downloaded periodontitis and IgAN data from the Gene Expression Omnibus (GEO) database. Differential expression analysis and weighted gene co-expression network analysis (WGCNA) were used to identify shared genes. Then, Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed on the shared genes. Hub genes were further screened using least absolute shrinkage and selection operator (LASSO) regression, and a receiver operating characteristic (ROC) curve was drawn according to the screening results. Finally, single-sample GSEA (ssGSEA) was used to analyze the infiltration level of 28 immune cells in the expression profile and its relationship with shared hub genes.

Results

By taking the intersection of WGCNA important module genes and DEGs, we found that the SPAG4, CCDC69, KRT10, CXCL12, HPGD, CLDN20 and CCL187 genes were the most important cross-talk genes between periodontitis and IgAN. GO analysis showed that the shard genes were most significantly enriched in kinase regulator activity. The LASSO analysis results showed that two overlapping genes (CCDC69 and CXCL12) were the optimal shared diagnostic biomarkers for periodontitis and IgAN. The immune infiltration results revealed that T cells and B cells play an important role in the pathogenesis of periodontitis and IgAN.

Conclusion

This study is the first to use bioinformatics tools to explore the close genetic relationship between periodontitis and IgAN. The SPAG4, CCDC69, KRT10, CXCL12, HPGD, CLDN20 and CCL187 genes were the most important cross-talk genes between periodontitis and IgAN. T-cell and B-cell-driven immune responses may play an important role in the association between periodontitis and IgAN.

Simultaneous Presence of Campylobacter rectus and Cnm-Positive Streptococcus mutans in the Oral Cavity Is Associated with Renal Dysfunction in IgA Nephropathy Patients: 5-Year Follow-Up Analysis

BACKGROUND

The simultaneous presence of Streptococcus mutans expressing the Cnm protein encoded by cnm (i.e., cnm-positive S. mutans) and Campylobacter rectus in the oral cavity has been associated with proteinuria in patients with IgA nephropathy (IgAN).

OBJECTIVES

The present study evaluated the relationship between renal function and oral bacteria in patients with IgAN over 5 years of follow-up.

METHODS

The presence of C. rectus and cnm-positive S. mutans in saliva samples of 117 patients with IgAN was initially evaluated by polymerase chain reaction. Patients were then divided into four groups according to the results of C. rectus and cnm-positive S. mutans detection: group A: C. rectus (-), cnm-positive S. mutans (-); group B: C. rectus (+), cnm-positive S. mutans (-); group C: C. rectus (-), cnm-positive S. mutans (+); and group D: C. rectus (+), cnm-positive S. mutans (+). Clinical characteristics were prospectively followed for 5 years.

RESULTS

Serum creatinine levels were significantly higher in group D than in group A over 5 years of follow-up. Additionally, the proportion of patients with an estimated glomerular filtration rate <45 mL/min increased over time; it was significantly greater in group D than in group A over 5 years of follow-up.

CONCLUSION

These results suggest that the simultaneous presence of C. rectus and cnm-positive S. mutans in the oral cavity is associated with renal dysfunction in IgAN patients.

Efficacy and limitations of additional steroid pulse therapy in IgA nephropathy patients whose hematuria did not remit on tonsillectomy and protocol steroid pulse therapy

BACKGROUND

Hematuria is the essential symptom of IgA nephropathy that has been suggested to be associated with long-term renal prognosis, Tonsillectomy and steroid pulse therapy (TSP), which is widely practiced in Japan, is effective for achieving hematuria remission. However, some cases are refractory to TSP, and additional steroid pulse therapy (SP) administered to these cases to achieve remission of hematuria. Nonetheless, the clinical significance of additional SP is unknown.

METHODS

In this retrospective study, we enrolled 99 patients from Okubo Hospital whose hematuria persisted following TSP. Patients were divided into the hematuria remission and non-remission groups. A multivariate regression analysis was performed on the factors that contributed to hematuria remission.

RESULTS

Following TSP, 103 of 403 patients (32.3%) did not achieve hematuria remission. Additional SP were performed in 99 of these patients, and remission of hematuria was achieved in 57 (57.6%). Patients with a greater degree of improvement in hematuria with TSP were significantly more likely to have remission of hematuria with additional SP (p = 0.0084*). Even in the hematuria non-remission group, both hematuria and proteinuria improved after additional SP.

CONCLUSION

In IgA nephropathy, additional SP could induce hematuria remission and reduce proteinuria.

Title IgA Nephropathy and Oral Bacterial Species Related to Dental Caries and Periodontitis

A relationship between IgA nephropathy (IgAN) and bacterial infection has been suspected. As IgAN is a chronic disease, bacteria that could cause chronic infection in oral areas might be pathogenetic bacteria candidates. Oral bacterial species related to dental caries and periodontitis should be candidates because these bacteria are well known to be pathogenic in chronic dental disease. Recently, several reports have indicated that collagen-binding protein (cnm)-(+) Streptococcs mutans is relate to the incidence of IgAN and the progression of IgAN. Among periodontal bacteria, Treponema denticola, Porphyromonas gingivalis and Campylobacte rectus were found to be related to the incidence of IgAN. These bacteria can cause IgAN-like histological findings in animal models. While the connection between oral bacterial infection, such as infection with S. mutans and periodontal bacteria, and the incidence of IgAN remains unclear, these bacterial infections might cause aberrantly glycosylated IgA1 in nasopharynx-associated lymphoid tissue, which has been reported to cause IgA deposition in mesangial areas in glomeruli, probably through the alteration of microRNAs related to the expression of glycosylation enzymes. The roles of other factors related to the incidence and progression of IgA, such as genes and cigarette smoking, can also be explained from the perspective of the relationship between these factors and oral bacteria. This review summarizes the relationship between IgAN and oral bacteria, such as cnm-(+) S. mutans and periodontal bacteria.