Recent advances in the immunological understanding of association between tonsil and immunoglobulin A nephropathy as a tonsil-induced autoimmune/inflammatory syndrome

Guidance of clinical management for patients with tonsillar focal disease

Tonsillar focal diseases (TFDs) are defined as "diseases caused by organic and/or functional damage in organs distant from tonsil, and the disease outcome is improved by tonsillectomy." Although several reports and reviews have shown the efficacy of tonsillectomy for TFDs, no guidelines for the clinical management of the diagnosis and treatment of TFDs have been reported. Therefore, the Society of Stomato-pharyngology established a committee to guide the clinical management of patients with TFDs, and the original guide was published in May 2023. This article summarizes the English version of the manuscript. We hope that the concept of TFDs will spread worldwide, and that one as many patients with TFDs will benefit from tonsillectomy.

Histological Correlation between Tonsillar and Glomerular Lesions in Patients with IgA Nephropathy Justifying Tonsillectomy: A Retrospective Cohort Study

Tonsillectomy with steroid pulse therapy (SPT) has been established as an effective treatment for immunoglobulin A nephropathy (IgAN) in Japan. However, the underlying mechanisms supporting tonsillectomy remain unclear. This study assessed palatine tonsils from 77 patients with IgAN, including 14 and 63 who received SPT before and after tonsillectomy, respectively. Tonsils from 21 patients with chronic tonsillitis were analyzed as controls. Specific tonsillar lesions were confirmed in patients with IgAN, correlating with active or chronic renal glomerular lesions and SPT. T-nodule and involution of lymphoepithelial symbiosis scores in tonsils correlated with the incidence of active crescents and segmental sclerosis in the glomeruli, respectively. The study revealed an essential role of the tonsil-glomerular axis in early active and late chronic phases. Moreover, the SPT-preceding group demonstrated no changes in the T-nodule score, which correlated with active crescent formation, but exhibited a considerable shrinkage of lymphatic follicles that produced aberrant IgA1. The study underscores the involvement of innate and cellular immunity in IgAN and advocates for tonsillectomy as a necessary treatment alongside SPT for IgAN, based on a stepwise process.

Paediatric pustulotic arthro-osteitis patient with an IL36RN variant, heterozygous c.115+6T>C, who was successfully treated with tonsillectomy: A case report and literature review

Pustulotic arthro-osteitis (PAO) is an infrequent condition, with its manifestation in children being even rare. Some reports propose an association between genetic variants and the onset of PAO. Currently, no definitive treatment protocol exists for paediatric patients with PAO. In this study, we present the paediatric case of PAO with an IL36RN variant who was successfully treated with tonsillectomy.

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.

Association of adenotonsillar disease and adenotonsillectomy with the development of vitiligo: A nationwide population-based cohort study

BACKGROUND

Vitiligo is a common acquired skin depigmentation disorder and is associated with various other autoimmune diseases which include thyroid disease and rheumatoid arthritis. Similarly, adenotonsillar disease (ATD) may induce inflammatory or autoimmune diseases in other organs which include the skin. However, the influence of ATD on the development of vitiligo has not been studied.

OBJECTIVES

To determine the association between ATD and adenotonsillectomy, and the development of vitiligo.

DESIGN AND METHODS

Using data from the National Health Insurance Service database, patients diagnosed with ATD between 2008 and 2010 were included in the study. We performed two rounds of 1:1 propensity score matching in the ATD and adenotonsillectomy groups. The ATD and non-ATD groups both included 206,514 individuals. Among the ATD group, the adenotonsillectomy and non-adenotonsillectomy groups both included 23,354 individuals. Each individual was monitored until 2019. The primary end point was the risk of vitiligo. Using the Cox Proportional Hazards model, the incidence of vitiligo and the hazard ratio (HR) were calculated.

RESULTS

The incidence of vitiligo was 1.16-fold higher in the ATD group than in the non-ATD group [adjusted HR (aHR), 1.16; 95% confidence interval (CI), 1.09-1.24] and 0.82-fold lower in the adenotonsillectomy group than in the non-adenotonsillectomy group (aHR, 0.82; 95% CI, 0.68-0.99). Additionally, the other risk factors for developing vitiligo included thyroid disease (aHR, 1.48; 95% CI, 1.11-1.98), age younger than 30 years (aHR, 1.18; 95% CI, 1.09-1.27), and age over 60 years (aHR, 1.22; 95% CI, 1.06-1.41), whereas factors including rural residency (aHR, 0.91; 95% CI, 0.85-0.98) and low economic status (aHR 0.87; 95% CI, 0.82-0.93) were associated with decreased incidence of vitiligo.

CONCLUSION

In this study, ATD increases the risk of vitiligo and adenotonsillectomy attenuates its development. Clinicians should consider ATD as a pathogenic factor for vitiligo and the potential effect of adenotonsillectomy in its management.

Epipharyngeal Abrasive Therapy (EAT) Reduces the mRNA Expression of Major Proinflammatory Cytokine IL-6 in Chronic Epipharyngitis

The epipharynx, located behind the nasal cavity, is responsible for upper respiratory tract immunity; however, it is also the site of frequent acute and chronic inflammation. Previous reports have suggested that chronic epipharyngitis is involved not only in local symptoms such as cough and postnasal drip, but also in systemic inflammatory diseases such as IgA nephropathy and myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) and Long COVID. Epipharyngeal Abrasive Therapy (EAT), which is an effective treatment for chronic epipharyngitis in Japan, is reported to be effective for these intractable diseases. The sedation of chronic epipharyngitis by EAT induces suppression of the inflammatory cytokines and improves systemic symptoms, which is considered to be one of the mechanisms, but there is no report that has proved this hypothesis. The purpose of this study was to clarify the anti-inflammatory effect of EAT histologically. The study subjects were 8 patients who were not treated with EAT and 11 patients who were treated with EAT for chronic epipharyngitis for 1 month or more. For immunohistochemical assessment, the expression pattern of IL-6 mRNA, which plays a central role in the human cytokine network, was analyzed using in situ hybridization. The expression of IL-6 in the EAT-treated group was significantly lower than those in the EAT nontreated group (p = 0.0015). In addition, EAT suppressed the expression of tumor necrosis factor alpha (TNFα), a crucial proinflammatory cytokine. As a result, continuous EAT suppressed submucosal cell aggregation and reduced inflammatory cytokines. Thus, EAT may contribute to the improvement of systemic inflammatory diseases through the suppression of IL-6 expression.

Treatment strategy with multidrug therapy and tonsillectomy pulse therapy for childhood-onset severe IgA nephropathy

BACKGROUND

IgA nephropathy is a typical chronic glomerulonephritis that tends to occur in childhood.

METHOD

We reviewed the report on pathogenesis, treatment strategy with multidrug therapy and tonsillectomy pulse therapy for childhood-onset severe IgA nephropathy to clarify the pathophysiology and treatment of IgA nephropathy in childhood.

RESULTS

In recent years, it has been found that the pathogenesis at onset is associated with aberrant glycosylation at the IgA1 hinge. Given this genetic background, the aberrantly glycosylated IgA1immune complex produced by antigen-stimulated T cells and B cells is deposited in the glomeruli. Inflammation is induced via activation of the complement, macrophages and mesangial cells, and glomerular damage progresses thereafter. Treatment is selected according to the severity of IgA nephropathy. In order to prevent the development of renal damage, it is important to control the associated immune responses. For severe IgA nephropathy, in particular, multidrug therapy with prednisolone, immunosuppressants, and angiotensin enzyme synthesis inhibitors and tonsillectomy methylprednisolone pulse therapy are now performed- and, as a result, the number of renal deaths has decreased and the long-term prognosis has improved.

CONCLUSION

The prognosis of IgA nephropathy is improving. In the future, it will be important to develop a treatment method that takes into consideration the fact that children are in their growth and development stage and, therefore, seeks to minimizes side effects.

Role of Palatine Tonsil and Epipharyngeal Lymphoid Tissue in the Development of Glomerular Active Lesions (Glomerular vasculitis) in Immunoglobulin A Nephropathy

Hematuria is an essential symptom of immunoglobulin A nephropathy (IgAN). Although the etiology of hematuria in IgAN has not been fully elucidated, it is thought that the rupture of the glomerular basement membranes caused by intra-capillary leukocyte influx, so-called glomerular vasculitis, is the pathological condition responsible for severe hematuria. Glomerular vasculitis are active lesions that exist in the glomeruli of acute phase IgAN and it is important because it is suspected to make the transition to segmental glomerular sclerosis (SGS) as a repair scar lesion in the chronic phase, and the progression of SGS would eventually lead to glomerular obsolescence. Worsening of hematuria concomitant with acute pharyngitis is common in patients with IgAN; therefore, elucidating the relationship between the immune system of Waldeyer's ring, including the palatine tonsil and epipharyngeal lymphoid tissue, and the glomerular vasculitis may lead to understanding the nature of IgAN. The epipharynx is an immunologically activated site even under normal conditions, and enhanced activation of innate immunity is likely to occur in response to airborne infection. Hyperactivation of innate immunity via upregulation of Toll-like receptors in the interfollicular area of the palatine tonsil and epipharyngeal lymphoid tissue, followed by enhanced fractalkine/CX3CR1 interactions, appears to play an important role in the development of glomerular vasculitis in IgAN. As latent but significant epipharyngitis is present in most patients with IgAN, it is plausible that acute upper respiratory infection may contribute as a trigger for the innate epipharyngeal immune system, which is already upregulated in a chronically inflamed environment. Given that epipharyngitis and its effects on IgAN are not fully understood, we propose that the so-called "epipharynx-kidney axis" may provide an important focus for future research.

Cost Analysis of Screening for IgA Nephropathy Using Novel Biomarkers

OBJECTIVES

IgA nephropathy (IgAN) is the most common primary chronic glomerulonephritis and a major cause of end-stage kidney disease worldwide. Novel biomarkers, including the aberrantly glycosylated IgA1 and glycan-specific antibodies, could be useful in the diagnosis of IgAN. The aim of this study was to assess the cost analysis of IgAN screening using novel biomarkers in addition to the conventional screening compared with conventional screening alone.

METHODS

To estimate the medical expense of each strategy related to renal disease for 40 years, we developed an analytical decision model. The decision tree started at "40 years of age with first-time hematuria." It simulated 2 clinical strategies: IgAN screening using the novel biomarkers (group N) and conventional screening (group C). The analysis results were presented as medical expenses from a societal perspective. Discounting was not conducted.

RESULTS

The expected medical expense per person for 40 years was ¥31.2 million (~$291 000) in group N and ¥33.4 million (~$312 000) in group C; hence, expense in group N was lower by ¥2.2 million (~$21 000). In group N, the expected value of IgAN increased by 5.67% points (N 48.44%, C 42.77%) and that of dialysis introduction decreased by 0.85% points (N 19.06%, C 19.91%). In the sensitivity analysis, expenses could be reduced in almost all cases except when renal biopsy using conventional screening was performed at the rate of 73% or higher.

CONCLUSION

Screening for IgAN using novel biomarkers would reduce renal disease-related expenses.

The mucosal immune system and IgA nephropathy

The precise pathogenesis of immunoglobulin A nephropathy (IgAN) is still not clearly established but emerging evidence confirms a pivotal role for mucosal immunity. This review focuses on the key role of mucosa-associated lymphoid tissue (MALT) in promoting the onset of the disease, underlying the relationship among microbiota, genetic factors, food antigen, infections, and mucosal immune response. Finally, we evaluate potential therapies targeting microbes and mucosa hyperresponsiveness in IgAN patients.

Tonsillectomy Improved Therapeutic Response in Anti-SRP Myopathy With Chronic Tonsillitis

Chronic tonsillitis has been attracted attention as a source of abnormal immune responses and a possible trigger of autoimmune diseases such as IgA nephritis, IgA vasculitis, palmoplantar pustulosis, psoriasis, rheumatoid arthritis, Behçet’s disease, and myositis. Here we present the first report of anti–signal recognition particle antibody–associated necrotizing myopathy (anti-SRP myopathy) with IgA nephropathy and chronic tonsillitis in which the therapeutic response to intravenous immunoglobulin (IVIG) treatment was dramatically improved after tonsillectomy and accompanied by a rapid increase in ΔIgG, defined as the change in serum IgG levels 2 weeks after the start of IVIG treatment relative to pre-treatment levels. Moreover, serum anti-SRP antibody titers became undetectable after tonsillectomy even though the resected tonsils did not produce anti-SRP antibodies. Tonsillectomy should be considered when chronic tonsillitis is observed in patients with autoimmune diseases showing poor response to treatment, including anti-SRP myopathy.

The potentially therapeutic role of tonsillectomy in the alleviation of several renal diseases apart from IgA nephropathy

Tonsils are located mainly at the gateway of the respiratory tract, and are reportedly one of the secondary lymphatic organs of the immune system. The development of several diseases including IgA nephropathy (IgAN) is associated with inflammatory stimulation and an aberrant immune response of the tonsils. Several studies have reported an improvement in and/or an increase in the stability of the clinicopathological findings of patients with IgAN post tonsillectomy. However, the efficacy in and precise mechanism of the alleviation of symptoms of other renal diseases by tonsillectomy remain unknown. We hypothesize that tonsillectomy may play a potentially therapeutic role in renal diseases apart from IgAN, which are thought to be caused by an impaired regulation of the immune system.

Association Between Galactose-Deficient IgA1 Derived From the Tonsils and Recurrence of IgA Nephropathy in Patients Who Underwent Kidney Transplantation

Background: Recurrence of IgA nephropathy (IgAN) in the transplanted kidney is associated with graft survival, but no specific treatment is available. Tonsillectomy (TE) reportedly arrests the progression of IgAN in the native kidney. Thus, we conducted a single-center retrospective cohort study to evaluate the effect of TE prior to IgAN recurrence.

Methods: Of the 36 patients with biopsy-proven IgAN who underwent kidney transplantation, 27 were included in this study. Nine patients underwent TE at 1 year after kidney transplantation (group 1), and the remaining 18 did not undergo TE (group 2).

Results: The rate of histological IgAN recurrence was significantly lower in group 1 than in group 2 (11.1 vs. 55.6%, log-rank p = 0.046). In addition, half of the recurrent patients in group 2 exhibited active lesions, compared to none in group 1. Serum Gd-IgA1 levels decreased after TE in group 1, whereas they remained stable or increased slightly in group 2. In the recurrent cases, IgA and Gd-IgA1 were found in the germinal center in addition to the mantle zone of tonsils. Finally, mesangial IgA and Gd-IgA1 immunoreactivity was reduced after TE in some cases.

Conclusion: Our data suggest that TE at 1 year after kidney transplantation might be associated with the reduced rate of histological IgAN recurrence. TE arrested or reduced serum Gd-IgA1 and mesangial Gd-IgA1 immunoreactivity. Therefore, we generated a hypothesis that serum Gd-IgA1 derived from the tonsils may play a pivotal role in the pathogenesis of IgAN. Based on these findings, we need to conduct verification in a prospective randomized controlled trial.

Analysis of microbial changes in the tonsillar formalin-fixed paraffin-embedded tissue of Chinese patients with IgA nephropathy

BACKGROUND

Immunoglobulin A nephropathy (IgAN) is a prevalent chronic glomerular disease contribution to end-stage renal failure (ESRD). The tonsillar microbiota is closely associated with IgAN diseases based on the mucosal immune response. However, the composition and function of in tonsillar microbiota in participant patients with IgAN remains unknown. In this study, we detected the tonsillar microbiota changes of IgAN patients in Heilongjiang province located in northeast China.

MATERIAL AND METHODS

We collected from 21 patients with IgAN and 16 patients with chronic tonsillitis (CT) who had undergone tonsillectomy previously. Histological review of all samples from formalin-fixed paraffin-embedded (FFPE) tissue were performed. Extracted DNA from FFPE tissue blocks, after that V4 regions of 16S ribosomal RNA (rRNA) sequencing and comparative analyses of tonsillar flora between two groups were performed. The statistical analysis used the SPSS version of 21.

RESULTS

Visualization of microorganisms by Gram and Warthin-Starry (WS) silver stains, preliminarily observed the morphological characteristics of microbiome in FFPE tissue cases, such as bacteria or fungi. Tonsillar FFPE samples from the IgAN patients and CT controls showed significant differences in tonsillar microbial certain compositions and functions. We found that there were eight dominant genera that can be available to distinguish IgAN patients from CT controls. Compared with CT controls, at genus level, the relative abundances of Methylocaldum and unclassified_f_Prevotellaceae were significantly higher, while the abundances of Anaerosphaera, Halomonas, Trichococcus, Peptostreptococcus, norank_f_Synergistaceae and unclassified_k_norank_d_Bacteria were significantly lower in IgAN patients. Principal co-ordinates analysis (PCOA) distinguished IgAN patients from CT controls, and receiver operating characteristic (ROC) curves analysis confirmed that the diagnosis of disease has certain diagnostic significance. In addition, Functional analysis revealed that partly Enzymes and KOs were increased in the IgAN patients.

CONCLUSIONS

Histological screening results were very helpful for further gene sequencing, not only to supplement the observation of bacterial morphology and structure, but also to prepare for subsequent gene sequencing and bioinformatics analysis. We elucidated subtle relevance between changes in tonsillar microbiota and IgAN patients, which can be utilized to predict the incidence of IgAN disease. In addition, we predicted that some enzymes, and KOs were closely related to IgAN.

The analysis of treatment of Immunoglobulin A-nephropathy

Aim. An evaluation of the effectiveness of immunosuppressive therapy (IST) and tonsillectomy (TE) in patients with IgA nephropathy (IgAN). Materials and methods. A retrospective cohort of the study included cases with biopsy proven primary IgAN (n=367, age 3412 years, men 55%). We used demographic and clinical and morphological parameters at the time of biopsy. Median followup period was 26 (10; 61) months. Outcomes were remission (complete or partial) and the progression of IgAN (defined as the start of dialysis or a decrease in glomerular filtration rate 50% from baseline). All patients received treatment with renin angiotensin system blockers. Evaluation of the effectiveness of therapy was carried out using propensity score (PS) methods matching, conventional double robust regression models with PS as independent covariate, and inverse probability weighting. Following patient subgroups were used for comparative analyses: with IST (n=176) and without IST (n=191); with TE (n=63) and without TE (n=304); without IST and without TE (IST-TE-; n=162); with TE and without IST (IST-TE+; n=29); with IST and without TE (IST+TE-; n=142); with IST and with TE (IST+ TE+; n=34). Results. All PS methods used gave close estimates of the comparative effectiveness of treatment in different subgroups: 1) patients on monotherapy with corticosteroids (CS) and combination of CS with other immunosuppressants did not have significant differences in probabilities of IgAN progression (hazard ratio 0.919; 95% CI 0.3332.950) and remission (odds ratio 0.919; 95% CI 0.3792.344) and were further combined into a group of IST; 2) IST was significantly associated with the lower risk of disease progression and increased odds ratio for remission; 3) the positive effects of IST were limited to cases with proteinuria 2 g/24 h; 4) the likelihood of IgAN remission and progression did not differ significantly between TE+ and TE-, IST-TE+ and IST-TE- groups. There were no cases of disease progression in the IST+TE+ group. The cumulative renal survival was higher in the IST+TE+ group compared to IST+ TE- group (p=0.010), while the probability of remission did not differ. Conclusion. IST was associated with a lower risk of IgAN progression and increased probability of remission, while these effects of IST were limited to patients with proteinuria 2 g/24 h. TE in combination with IST is associated with an additional reduction in the risk of disease progression.

The Role of Immune Modulation in Pathogenesis of IgA Nephropathy

IgA nephropathy (IgAN) is the most prevalent primary glomerulonephritis worldwide, with diverse clinical manifestations characterized by recurrent gross hematuria or microscopic hematuria, and pathological changes featuring poorly O-galactosylated IgA1 deposition in the glomerular mesangium. Pathogenesis has always been the focus of IgAN studies. After 50 years of research, most scholars agree that IgAN is a group of clinicopathological syndromes with certain common immunopathological characteristics, and multiple mechanisms are involved in its pathogenesis, including immunology, genetics, and environmental or nutritional factors. However, the precise pathogenetic mechanisms have not been fully determined. One hypothesis about the pathogenesis of IgAN suggests that immunological factors are engaged in all aspects of IgAN development and play a critical role. A variety of immune cells (e.g., dendritic cells, NK cells, macrophages, T-lymphocyte subsets, and B-lymphocytes, etc.) and molecules (e.g., IgA receptors, Toll-like receptors, complements, etc.) in innate and adaptive immunity are involved in the pathogenesis of IgAN. Moreover, the abnormality of mucosal immune regulation is the core of IgAN immunopathogenesis. The roles of tonsil immunity or intestinal mucosal immunity, which have received more attention in recent years, are supported by mounting evidence. In this review, we will explore the latest research insights on the role of immune modulation in the pathogenesis of IgAN. With a better understanding of immunopathogenesis of IgAN, emerging therapies will soon become realized.

Recent advances in the immunological understanding of association between tonsil and immunoglobulin A nephropathy as a tonsil-induced autoimmune/inflammatory syndrome

INTRODUCTION

Immunoglobulin A nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide. It is well known that upper respiratory tract infections, particularly acute tonsillitis, often worsen IgAN. Recent many clinical studies clearly show that tonsillectomy with steroid pulse therapy is the effective treatments for IgAN patients. Recently, the immunological evidence of association between tonsil and IgAN has been reported.

METHODS

In this review, the mechanism underlying the onset of IgAN, as a tonsil-induced autoimmune/inflammatory syndrome (TIAS), is outlined with the main focus on the authors' research results.

RESULTS

In the tonsils of patients with IgAN, hyperimmune response to the unmethylated deoxycytidyl-deoxyguanosine oligodeoxynucleotides (CpG-ODN) take place, resulting in hyperproduction of interferon-γ. The hyperproduction is followed by both overproduction of mutated IgA via B-cell activating factor (BAFF)/a proliferation-inducing ligand (APRIL)-mediated pathways and overexpression of T-cell receptor Vβ6, CXCR3, and CX3CR1 on tonsillar T cells. These IgA and T cells home to the kidney via the systemic circulation, resulting in nephritis of IgAN.

CONCLUSIONS

Scientific evidence supporting the use of tonsillectomy has gradually accumulated. We hope that many additional researchers will publish new evidence linking the tonsils and kidneys in the future.