Clinical and immunological implications of increase in CD208+ dendritic cells in tonsils of patients with immunoglobulin A nephropathy

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.

Accelerated involution of germinal center in palatine tonsils in IgA nephropathy

BACKGROUND

Altered immunological responses in the palatine tonsils may be involved in the pathogenesis of IgA nephropathy (IgAN). The germinal center serves as the site for antigen-specific humoral immune responses in the palatine tonsils. Germinal center involution is frequently observed in the palatine tonsils of IgAN (IgAN tonsils). However, the pathogenic significance of these characteristic changes remains unclear. This study aimed to investigate the morphological changes in secondary lymphoid follicles in IgAN tonsils and to evaluate the correlation between the morphometric results and the clinicopathological severity of IgAN.

METHODS

The tonsils of age-matched patients with recurrent tonsillitis (RT tonsils) were used as controls. The correlation between the degree of lymphoid follicular involution and histopathological severities in clinical or kidney biopsy was evaluated.

RESULTS

In total, 87 patients with IgAN were included (48% male, median age 35 years, median estimated glomerular filtration rate: 74 mL/min/1.73 m2). Compared to RT tonsils, IgAN tonsils showed smaller median sizes of lymphoid follicles and germinal centers (P < 0.001). The relative areas of lymphoid follicles (%LFA) and germinal centers (%GCA) in the total tonsillar tissue were smaller in the IgAN tonsils than in the RT tonsils (P < 0.001). In contrast, the median proportion of mantle zones in the total tonsillar tissue was comparable between the groups. A lower %LFA was associated with a longer period from the onset of urinary abnormalities to biopsy diagnosis and higher urinary protein excretion (P = 0.01). %LFA showed significant negative correlations with frequencies of glomeruli with both global and segmental sclerosis.

CONCLUSIONS

The present study confirmed accelerated germinal center involution in the tonsils of patients with IgAN. This characteristic change in the IgAN tonsil correlates with heavy proteinuria and advanced chronic histopathological changes in the kidneys, thereby suggesting the involvement of repeated tonsillar immunoreactions during IgAN progression.

Identification of GMFG as a novel biomarker in IgA nephropathy based on comprehensive bioinformatics analysis

Background

IgA nephropathy (IgAN) stands as the most prevalent form of glomerulonephritis and ranks among the leading causes of end-stage renal disease worldwide. Regrettably, we continue to grapple with the absence of dependable diagnostic markers and specific therapeutic agents for IgAN. Therefore, this study endeavors to explore novel biomarkers and potential therapeutic targets in IgAN, while also considering their relevance in the context of tumors.

Methods

We gathered IgAN datasets from the Gene Expression Omnibus (GEO) database. Subsequently, leveraging these datasets, we conducted an array of analyses, encompassing differential gene expression, weighted gene co-expression network analysis (WGCNA), machine learning, receiver operator characteristic (ROC) curve analysis, gene expression validation, clinical correlations, and immune infiltration. Finally, we carried out pan-cancer analysis based on hub gene.

Results

We obtained 1391 differentially expressed genes (DEGs) in GSE93798 and 783 DGEs in GSE14795, respectively. identifying 69 common genes for further investigation. Subsequently, GMFG was identified the hub gene based on machine learning. In the verification set and the training set, the GMFG was higher in the IgAN group than in the healthy group and all of the GMFG area under the curve (AUC) was more 0.8. In addition, GMFG has a close relationship with the prognosis of malignancies and a range of immune cells.

Conclusions

Our study suggests that GMFG could serve as a promising novel biomarker and potential therapeutic target for both IgAN and certain types of tumors.

Cell-type-specific molecular characterization of cells from circulation and kidney in IgA nephropathy with nephrotic syndrome

Nephrotic syndrome (NS) is a relatively rare and serious presentation of IgA nephropathy (IgAN) (NS-IgAN). Previous research has suggested that the pathogenesis of NS-IgAN may involve circulating immune imbalance and kidney injury; however, this has yet to be fully elucidated. To investigate the cellular and molecular status of NS-IgAN, we performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) and kidney cells from pediatric patients diagnosed with NS-IgAN by renal biopsy. Consistently, the proportion of intermediate monocytes (IMs) in NS-IgAN patients was higher than in healthy controls. Furthermore, flow cytometry confirmed that IMs were significantly increased in pediatric patients with NS. The characteristic expression of VSIG4 and MHC class II molecules and an increase in oxidative phosphorylation may be important features of IMs in NS-IgAN. Notably, we found that the expression level of CCR2 was significantly increased in the CMs, IMs, and NCMs of patients with NS-IgAN. This may be related to kidney injury. Regulatory T cells (Tregs) are classified into two subsets of cells: Treg1 (CCR7 high, TCF7 high, and HLA-DR low) and Treg2 (CCR7 low, TCF7 low, and HLA-DR high). We found that the levels of Treg2 cells expressed significant levels of CCR4 and GATA3, which may be related to the recovery of kidney injury. The state of NS in patients was closely related to podocyte injury. The expression levels of CCL2, PRSS23, and genes related to epithelial-mesenchymal transition were significantly increased in podocytes from NS-IgAN patients. These represent key features of podocyte injury. Our analysis suggests that PTGDS is significantly downregulated following injury and may represent a new marker for podocytes. In this study, we systematically analyzed molecular events in the circulatory system and kidney tissue of pediatric patients with NS-IgAN, which provides new insights for targeted therapy in the future.

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.

Clinical and Pathological Implications of Increases in Tonsillar CD19+CD5+ B Cells, CD208+ Dendritic Cells, and IgA1-positive Cells of Immunoglobulin A Nephropathy

OBJECTIVE

Several studies indicated that tonsillectomy can improve the prognosis of patients with immunoglobulin A nephropathy (IgAN). However, the relationship between tonsillar immunity and IgAN is still unclear.

METHODS

A total of 14 IgAN patients were recruited in the current study from May 2015 to April 2016 in Tongji Hospital. B cells, dendritic cells (DCs), and IgA1 positive cells in human tonsils were detected using immunofluorescence and immunohistochemistry. Correlations between these cells and clinicopathologic features were evaluated.

RESULTS

CD19+CD5+ B cells were predominantly located in germinal centers and mantle zones of lymphoid follicles, the CD208+ DCs were distributed in the interfollicular and subepithelial area, and IgA1-positive cells were predominantly detected in mantle zones of lymphoid follicles and subepithelial tissues. The numbers of CD19+CD5+ B cells, CD208+ DCs, and IgA1-positive cells in tonsillar tissues from IgAN patients were significantly higher than those in the normal controls (P<0.01, respectively). CD19+CD5+ B cells, CD208+ DCs, and IgA1-positive cells in tonsillar tissues were significantly associated with 24-h proteinuria levels and tubular atrophy/interstitial fibrosis of IgAN.

CONCLUSION

CD19+CD5+ B cells, CD208+ DCs, and IgA1-positive cells in tonsillar tissues might be involved in the pathogenesis of IgAN.

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.

Identification of key biomarkers and signaling pathways and analysis of their association with immune cells in immunoglobulin A nephropathy

Introduction

Immunoglobulin A nephropathy (IgAN) is the most common glomerular disease worldwide, with a poor prognosis. The aim of our study was to identify key biomarkers and their associations with immune cells to aid in the study of IgAN pathology and immunotherapy.

Material and methods

The data of IgAN were downloaded from a public database. The metaMA package and limma package were used to identify differentially expressed mRNAs (DEmRNAs) and differentially expressed miRNAs (DEmiRNAs), respectively. Biological functions of the DEmRNAs were analyzed. Machine learning was used to screen the mRNA biomarkers of IgAN. Pearson's correlation coefficient was used to analyze the correlation between mRNA biomarkers, immune cells and signaling pathways. Moreover, we constructed a miRNAs-mRNAs targeted regulatory network. Finally, we performed in vitro validation of the identified miRNAs and mRNAs.

Results

1205 DEmRNAs and 125 DEmiRNAs were identified. In gene set enrichment analysis (GSEA), tumor necrosis factor α (TNF-α) signaling via nuclear factor κB (NF-κB), apoptosis and MTORC-1 signaling were inhibited in IgAN. 8 mRNA biomarkers were screened by machine learning. In addition, the distribution of 8 immune cell types was found to be significantly different between normal controls and IgAN by difference analysis. Pearson correlation coefficient analysis demonstrated that AKAP8L was significantly negatively correlated with CD4⁺ memory T-cells. AKAP8L was also significantly negatively correlated with TNF-α signaling via NF-κB, apoptosis, and MTORC-1 signaling. Subsequently, 5 mRNA biomarkers predicted corresponding negative regulatory miRNAs.

Conclusions

The identification of 8 important biomarkers and their correlation with immune cells and biological signaling pathways provides new ideas for further study of IgAN.

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 epipharynx-kidney axis triggers glomerular vasculitis in immunoglobulin A nephropathy

Macroscopic hematuria concomitant with acute pharyngitis is a characteristic feature of immunoglobulin A nephropathy (IgAN). Although the underlying mechanism of worsening hematuria has not been fully elucidated, activation of the innate immune system of nasopharynx-associated lymphoid tissue is thought to play an important role. 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. As latent but significant epipharyngitis presents in most IgAN patients, it is plausible that acute pharyngitis due to airway infection may contribute as a trigger of the epipharyngeal innate immune system, which is already upregulated in the chronically inflamed environment. The aim of this review was to discuss the mechanism of epipharynx-kidney axis involvement in glomerular vasculitis responsible for the worsening of hematuria in IgAN.

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.

PEPITEM/Cadherin 15 Axis Inhibits T Lymphocyte Infiltration and Glomerulonephritis in a Mouse Model of Systemic Lupus Erythematosus

Control of lymphocyte infiltration in kidney is a potential therapeutic strategy for lupus nephritis, considering that control of lymphocyte migration by sphingosine 1 phosphate has been implicated in inflammation-related pathology. The peptide inhibitor of the transendothelial migration (PEPITEM)/cadherin (CDH) 15 axis was recently reported to promote sphingosine 1 phosphate secretion. In this study, we investigated whether CDH15 is expressed in the kidney of MRL/lpr mice and whether lymphocyte infiltration is suppressed by exogenously administered PEPITEM. Mice (18 wk old) were randomized into 4-wk treatment groups that received PEPITEM or PBS encapsulated in dipalmitoylphosphatidylcholine liposomes. Enlargement of the kidney, spleen, and axillary lymph nodes was suppressed by PEPITEM treatment, which also blocked infiltration of double-negative T lymphocytes into the kidney and glomerular IgG/C3 deposition, reduced proteinuria, and increased podocyte density. Immunohistochemical analysis revealed that the PEPITEM receptor CDH15 was expressed on vascular endothelial cells of glomeruli and kidney arterioles, skin, and peritoneum in lupus mice at 22 wk of age but not in 4-wk-old mice. These results suggest that PEPITEM inhibits lymphocyte migration and infiltration into the kidney, thereby preserving the kidney structure and reducing proteinuria. Thus, PEPITEM administration may be considered as a potential therapeutic tool for systemic lupus erythematosus.

The therapeutic effect of dendritic cells expressing indoleamine 2,3-dioxygenase (IDO) on an IgA nephropathy mouse model

OBJECTIVE

IgA nephropathy (IgAN) is one of the most common glomerulonephritis in the world, especially in Asian population. IgAN usually progresses slowly, but it is still an important cause of chronic renal failure. IgAN is characterized by abnormal increase of IgA1 level and deposition in mesangium. At present, there is no specific treatment.

MATERIALS AND METHODS

Previous reports have shown that DC cells expressing immunosuppressive factors can significantly reduce the symptoms of arthritis in arthritis models. Indoleamine 2,3-dioxygenase (IDO) is an important tryptophan degrading enzyme and an important factor regulating immunotolerance. DC expressing functional IDO can inhibit effector T cells by consuming essential tryptophan and/or producing toxic metabolites and promoting the differentiation of Treg cells, which exhibits immunosuppressive effect. In this study, we constructed a IgAN mouse model. The mature DC cells overexpressing IDO were induced in vitro and transfused back to IgAN mice to observe their effects on inflammation and renal injury.

RESULTS

The results showed that overexpression of IDO did not affect the maturation of DC cells. The proportion of CD3 + CD4 + and CD3 + CD8 + cells decreased significantly and the proportion of CD4 + CD25 + Foxp3 + cells increased significantly in kidney tissue of IgAN mice after the reinfusion of IDO-expressing DC. The contents of IL-2, IL-4, IL-6, and IL-17A in kidney tissue of IgAN mice also decreased significantly, the damage of kidney tissue was alleviated, ACR was decreased, collagen fibre content in kidney tissue was decreased, and IgA deposition in glomerular mesangium was decreased in IgAN mice.

CONCLUSIONS

It has the potential to treat IgAN by upregulating the expression of IDO in DC cells by genetic engineering and reinfusion into vivo.

Comprehensive microbiome analysis of tonsillar crypts in IgA nephropathy

Background

Immunoglobulin A nephropathy (IgAN) is the most prevalent primary chronic glomerular disease, in which the mucosal immune response elicited particularly in the tonsils or intestine has been estimated to be involved in the development of the disease. To explore the relationship between IgAN and bacterial flora in the tonsils, we conducted a comprehensive microbiome analysis.

Methods

We enrolled 48 IgAN patients, 21 recurrent tonsillitis (RT) patients without urine abnormalities and 30 children with tonsillar hyperplasia (TH) who had undergone tonsillectomy previously. Genomic DNA from tonsillar crypts of each patient was extracted, and V4 regions of the 16S ribosomal RNA gene were amplified and analysed using a high-throughput multiplexed sequencing approach. Differences in genus composition among the three study groups were statistically analysed by permutational multivariate analysis of variance and visualized by principal component analysis (PCA).

Results

Substantial diversity in bacterial composition was detected in each sample. Prevotella spp., Fusobacterium spp., Sphingomonas spp. and Treponema spp. were predominant in IgAN patients. The percentage of abundance of Prevotella spp., Haemophilus spp., Porphyromonas spp. and Treponema spp. in IgAN patients was significantly different from that in TH patients. However, there was no significant difference in the percentage of abundance of any bacterial genus between IgAN and RT patients. PCA did not distinguish IgAN from RT, although it discriminated TH. No significant differences in microbiome composition among the groups of IgAN patients according to clinicopathological parameters were observed.

Conclusions

Similar patterns of bacteria are present in tonsillar crypts of both IgAN and RT patients, suggesting that the host response to these bacteria might be important in the development of IgAN.

Steroid pulse therapy transiently destroys the discriminative histological structure of tonsils in IgA nephropathy: Tonsillectomy should be performed before or just after steroid pulse therapy

OBJECTIVE

Tonsillectomy combined with steroid-pulse therapy is a widely accepted method for the treatment of IgA nephropathy (IgAN) in Japan. However, the indication of tonsillectomy for IgAN is still controversial, and the timing of tonsillectomy is not clearly defined for the protocol of this therapy. Based on the results of a randomized control trial in Japan, the Evidence-Based Clinical Practice Guidelines for IgA nephropathy 2014 (edited in Japan) recommended tonsillectomy combined with steroid-pulse therapy for Grade C1. However, this is not widely accepted worldwide. To clarify the validity and timing of tonsillectomy, we evaluated how the three-consecutive steroid-pulse therapy method affects the tonsil tissues of IgAN patients.

METHODS

We examined tonsil specimens from 35 IgAN patients and 8 chronic tonsillitis patients. We compared the proportion of follicular area to total tonsillar area and the number of germinal centers between each group on hematoxylin and eosin stained pathological specimens to clarify the histopathological characteristics of tonsils from IgAN patients. Based on these findings, we examined the tonsils of patients after three-consecutive steroid-pulse therapy treatments (n=34) to determine the influence of this therapy on the tonsil tissues of IgAN patients. Moreover, we observed chronological changes in tonsil tissues after steroid-pulse therapy.

RESULTS

The extrafollicular area was enlarged in IgAN patients before steroid-pulse therapy compared with chronic tonsillitis patients. Just after steroid-pulse therapy, the follicles became very small with blurry outlines, and the number of germinal centers was remarkably decreased. With a gradual decrease in oral prednisolone, the tonsil tissue structure was gradually restored.

CONCLUSION

Tonsillectomy combined with steroid-pulse therapy is considered a reasonable treatment for IgAN. Steroid-pulse therapy-induced histological changes in tonsils were transient, indicating tonsillectomy should be performed before or just after steroid-pulse therapy.

The size of palatine tonsils cannot be used to decide the indication of tonsillectomy for IgA nephropathy

Background. Tonsillectomy is one of the treatment strategies for immunoglobulin A nephropathy (IgAN). The relationship between the indication of tonsillectomy and the size of palatine tonsils (PTs) in patients with IgAN remains controversial.

Methods. This retrospective cohort study investigated 57 patients with IgAN who underwent tonsillectomy combined with steroid pulse therapy (SPT). They were classified into two groups, the hypertrophy group and the nonhypertrophy group, according to the weight of their excised PTs. The effects of tonsillectomy combined with SPT on clinical remission (CR) and the histopathological findings of PTs were compared between the two groups.

Results. During the mean follow-up period of 45.5 (range 6–133) months, 78.9% of the patients achieved CR (79.3 versus 78.6%, P = 0.945) and the baseline serum creatinine doubled only in one patient in the nonhypertrophy group (0 versus 3.6%, P = 0.491). No significant difference was observed in the incidence of CR between the two groups by the Kaplan–Meier method (P = 0.839). The predictor for CR, identified in Cox proportional hazards models, was baseline proteinuria [hazard ratio 0.14 (95% CI 0.032–0.621) P = 0.010]. Although macroscopic pus plugs were observed on the surface of PTs in almost 60% of patients in each group, microscopic pus plugs in the crypt and the enlarged interfollicular area were observed in all patients.

Conclusions. The treatment effect of tonsillectomy combined with SPT and the pathological features of PTs in IgAN were equal, regardless of the size of the PTs. Therefore, the size of PTs should not be included as a factor when deciding the indication of tonsillectomy for IgAN.

Renoprotective effects of a dipeptidyl peptidase 4 inhibitor in a mouse model of progressive renal fibrosis

Although the effects of dipeptidyl peptidase 4 (DPP-4) inhibitors beyond their hypoglycemic action have been reported, whether these inhibitors have renoprotective effects in nondiabetic chronic kidney disease (CKD) is unclear. We examined the therapeutic effects of DPP-4 inhibition in mice with unilateral ureteral obstruction (UUO), a nondiabetic model of progressive renal fibrosis. After UUO surgery, mice were administered either the DPP-4 inhibitor alogliptin or a vehicle by oral gavage once a day for 10 days. Physiological parameters, degrees of renal fibrosis and inflammation, and molecules related to renal fibrosis and inflammation were then evaluated using sham-operated mice as controls. Positive area of α-smooth muscle actin was significantly smaller and expression of transforming growth factor β messenger RNA was significantly lower in the alogliptin-treated group than in the vehicle-treated group. Renal total collagen content was also significantly lower in the alogliptin-treated group than in the vehicle-treated group. These results suggest that alogliptin exerted renoprotective antifibrotic effects. The positive area of F4/80 was significantly smaller and expression of CD68 messenger RNA was significantly lower in the alogliptin-treated group than in the vehicle-treated group, suggesting an anti-inflammatory action by the DPP-4 inhibitor. Compared to the results for the vehicle-treated group, expression of markers for M1 macrophages tended to be lower in the alogliptin-treated group, and the relative expression of M2 macrophages tended to be higher. These data indicate the various protective effects of DPP-4 inhibition in nondiabetic mice with UUO. DPP-4 inhibitors may therefore be promising therapeutic choices even for nondiabetic CKD patients.

Comparison of oral steroids with tonsillectomy plus steroid pulse therapy in patients with IgA nephropathy

BACKGROUND

Treatment of IgA nephropathy (IgAN) in Japan has recently changed, from oral prednisolone (oPSL) to tonsillectomy plus steroid pulse (TSP) therapy. However, a few studies have compared their efficacy and safety.

METHODS

IgAN patients diagnosed in our institution between 1991 and 2013, treated with TSP or oPSL, aged ≥16 years, with ≥1 g/day proteinuria, and estimated glomerular filtration rate (eGFR) ≥30 ml/min/1.73 m², and no other renal disease were selected. Baseline clinical and histological findings, clinical outcomes, and adverse events were compared. Clinical remission (CR) was defined as <0.3 g/day proteinuria and <5 urinary red blood cells per high-powered field.

RESULTS

Sixty-six patients were identified; after propensity score adjustment, 26 patients were selected in each group. CR rates were significantly higher at 12 (30.8 % vs. 3.9 %), 36 (47.3 % vs. 7.9 %), and 72 (57.8 % vs. 20.1 %) months (p < 0.01), and the renal survival rate, defined as the development of a 25 % reduction from baseline eGFR, was significantly higher at 12 (96.2 % vs. 69.2 %), 36 (96.2 % vs. 61.5 %), and 72 (96.2 % vs. 41.0 %) months in the TSP than the oPSL group (p < 0.001). Multivariate analysis showed that TSP was the only independent factor associated with CR (hazard ratio, 3.58; 95 % confidence interval, 1.32-10.91, p = 0.01). The number of patients with adverse events was significant lower in TSP group than in oPSL group (11.5 % vs. 34.6 %, p = 0.04).

CONCLUSIONS

CR rates are higher; protection of renal function and prevention from adverse events were superior with TSP than with oPSL in patients with IgAN and moderate-to-severe proteinuria.

Expression of human T cell immunoglobulin domain and mucin-3 on kidney tissue from immunoglobulin A nephropathy patients

The aim of this study was to evaluate the expression of human T cell immunoglobulin domain and mucin-3 (Tim-3) in renal tissue from patients with immunoglobulin A nephropathy (IgAN) and without IgAN and to evaluate the difference in Tim-3 expression between them. A total of 71 patients with IgAN as IgA group and 13 patients without IgAN as control group were enrolled in the present study. Patients in IgAN accepted percutaneous renal biopsy. We examined the expression of Tim-3 in renal tissue and the serological parameters in serum from all enrolled cases. The expression of Tim-3 and serological parameters were compared between the different groups. Positive staining of Tim-3 protein was seen in 94.3 % patients with IgAN (67 out of 71), but only 15.4 % (2 out of 13) in the cases without IgAN were positive staining of Tim-3. There were significant differences between two groups in almost all serological markers, which reflect IgAN activity. There was a nearly positive correlation between pathological manifestations and expression degree of Tim-3. High immuno-reactivity of Tim-3 was found to be significantly correlated with serological grade (p < 0.001) in IgA group, but there was no such phenomenon in control group. The results showed that there was the expression of Tim-3 in renal tissue from the patients with IgAN, but rarely expression in cases without IgAN. Expression of Tim-3 was associated with the diseases' activity.