Comparison of effective impact among tonsillectomy alone, tonsillectomy combined with oral steroid and with steroid pulse therapy on long-term outcome of immunoglobulin A nephropathy

Effect of tonsillectomy combined with steroid pulse therapy upon IgA nephropathy depending on proteinuria status at diagnosis: a nationwide multicenter cohort study in Japan

BACKGROUND

The effects of tonsillectomy combined with steroid pulse (TSP) therapy for IgA nephropathy (IgAN) are little known. Therefore, we examined the effects of TSP therapy on the kidney outcomes of IgAN in a large, nationwide cohort study in Japan.

METHODS

Between 2002 and 2004, 632 IgAN patients with ≥ 0.5 g/day proteinuria at diagnosis were divided into three groups with mild (0.50-0.99 g/day; n = 264), moderate (1.00-1.99 g/day, n = 216), or severe (≥ 2.00 g/day; n = 153). Decline in kidney function and urinary remission were compared among the three groups after TSP therapy, corticosteroid (ST) therapy, or conservative therapy during a mean follow-up of 6.2 ± 3.3 years. 10.6% and 5.9% of patients in the ST and conservative therapy group underwent tonsillectomy.

RESULTS

The rate of urinary remission at the final observation was significantly higher in the TSP therapy group than in the ST or conservative therapy groups (mild proteinuria: 64%, 43%, and 41%; moderate proteinuria: 51%, 45%, and 28%; severe proteinuria: 48%, 30%, and 22%, respectively). In contrast, the rate of a 50% increase in serum creatinine was lower in groups TSP therapy, than ST or conservative therapy (mild proteinuria: 2.1%, 10.1% and 16.7%; moderate proteinuria: 4.8%, 8.8% and 27.7%; severe proteinuria: 12.0%, 28.9% and 43.1%, respectively). In multivariate analysis, TSP therapy significantly prevented a 50% increase in serum creatinine levels compared with conservative therapy in groups with moderate and severe proteinuria (hazard ratio, 0.12 and 0.22, respectively).

CONCLUSION

TSP significantly increased the rate of proteinuria disappearance and urinary remission in IgAN patients with mild-to-moderate urinary protein levels. It may also reduce the decline in kidney function in patients with moderate-to-severe urinary protein levels.

A comparison of the clinical efficacy of tonsillectomy with steroid pulse therapy and tonsillectomy therapy alone for patients with immunoglobulin A nephropathy: a retrospective observational study

BACKGROUND

Tonsillectomy with steroid pulse therapy (TSP) and tonsillectomy monotherapy (T) have improved the prognosis of patients with immunoglobulin A nephropathy (IgAN). However, a consensus has not been reached on the best treatment for these patients. This study aimed to compare the efficacies of TSP and T.

METHODS

Data of patients with IgAN who received TSP or T were retrospectively analyzed. The exclusion criterion was a serum creatinine level > 1.5 mg/dL. The clinical remission and renal survival rates were compared.

RESULTS

Patients were divided into groups based on the treatment method: the TSP (n = 82) and T groups (n = 41). No significant differences were observed in patient characteristics, except for the observation period (TSP: 60 months, T: 113 months). The log-rank test revealed that the clinical remission rate was significantly higher in the TSP group than in the T group (p < 0.05). The superiority of TSP was also observed in the urinary protein excretion (> / = or < 1 g/day) of the two subgroups. According to the Cox proportional-hazards model, the treatment method and daily urinary protein extraction were independent factors affecting clinical remission. The 10-year renal survival rates in the TSP and T groups were 100% and 92.5%, respectively. The log-rank test revealed a tendency for a higher renal survival rate in the TSP group than in the T group (p = 0.09).

CONCLUSION

The clinical remission rate was significantly higher with TSP than with T, regardless of urinary protein levels. TSP tended to have a better renal survival rate than T.

Bioinformatics analysis reveals novel hub gene pathways associated with IgA nephropathy

BACKGROUND

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulopathy worldwide. However, the molecular events underlying IgAN remain to be fully elucidated. This study aimed to identify novel biomarkers of IgAN through bioinformatics analysis and elucidate the possible molecular mechanism.

METHODS

Based on the microarray datasets GSE93798 and GSE37460 downloaded from the Gene Expression Omnibus database, the differentially expressed genes (DEGs) between IgAN samples and normal controls were identified. Using the DEGs, we further performed a series of functional enrichment analyses. Protein-protein interaction (PPI) networks of the DEGs were constructed using the STRING online search tool and were visualized using Cytoscape. Next, hub genes were identified and the most important module among the DEGs, Biological Networks Gene Ontology tool (BiNGO), was used to elucidate the molecular mechanism of IgAN.

RESULTS

In total, 148 DEGs were identified, comprising 53 upregulated genes and 95 downregulated genes. Gene Ontology (GO) analysis indicated that the DEGs for IgAN were mainly enriched in extracellular exosome, region and space, fibroblast growth factor stimulus, inflammatory response, and innate immunity. Module analysis showed that genes in the top 1 significant module of the PPI network were mainly associated with innate immune response, integrin-mediated signaling pathway and inflammatory response. The top 10 hub genes were constructed in the PPI network, which could well distinguish the IgAN and control group in monocyte and tissue samples. We finally identified the integrin subunit beta 2 (ITGB2) and Fc fragment of IgE receptor Ig (FCER1G) genes that may play important roles in the development of IgAN.

CONCLUSIONS

We identified key genes along with the pathways that were most closely related to IgAN initiation and progression. Our results provide a more detailed molecular mechanism for the development of IgAN and novel candidate gene targets of IgAN.

Impact of the number of steroid pulses in tonsillectomy combined with steroid pulse therapy: a nationwide retrospective study in Japan

BACKGROUND

Steroid pulse therapy with tonsillectomy is known as a major treatment for IgA nephropathy (IgAN). However, its protocol was different among institutions and the effects of varying the number of steroid pulses remain unclear.

METHODS

From a total of 1,174 IgAN patients in a multicenter retrospective cohort analysis in Japan, 195 patients were treated by tonsillectomy combined with corticosteroid. They were divided into four groups based on the number of administered steroid pulses from 0 to three (TSP0-3), and remission of urinary abnormalities and renal survival until 1.5-fold increase in serum creatinine level from baseline were analyzed among the four groups and between TSP1 and TSP3.

RESULTS

Among the four groups, renal function was relatively good when the estimated glomerular filtration rate was approximately 80-90 mL/min/1.73m² and proteinuria was relatively mild (< 1.0 g/gCre). The ratio of patients who developed renal dysfunction was < 5% in all groups, and the cumulative renal survival rate by Kaplan-Meier analysis was similar among groups (log-rank test, p = 0.37), despite varying clinical backgrounds and treatments. After adjustment of the background variables between TSP1 and TSP3, the remission rates of urinary abnormalities were similar and the renal survival rate also remained similar (66.8 vs. 85.4%, p = 0.45).

CONCLUSIONS

In patients with mild proteinuria and good renal function, the number of steroid pulses did not affect the renal outcome in steroid pulse therapy with tonsillectomy. The adaptation and protocols, such as the number of steroid pulses, should be determined for each IgAN patient's background.

Estimated plasma osmolarity and risk of end-stage kidney disease in patients with IgA nephropathy

BACKGROUND

Several experimental studies have indicated that increased plasma osmolarity caused by recurrent dehydration is involved in kidney injury via a mechanism, mediated by vasopressin secretion and activation of the aldose reductase pathway. Epidemiologic evidence linking increased plasma osmolarity and the onset of end-stage kidney disease (ESKD), in patients with primary glomerulonephritis, is lacking.

METHODS

We retrospectively examined 663 patients with IgA nephropathy (IgAN) diagnosed by kidney biopsy and evaluated the association between estimated plasma osmolarity and ESKD prevalence, using a Cox proportional hazards model.

RESULTS

During follow-up (median 80.4 months; interquartile range 22.2-120.1), 73 patients developed ESKD. In a baseline survey, plasma osmolarity was correlated negatively with the mean value of the estimated glomerular filtration rate, but correlated positively with the mean value of urinary protein excretion, systolic blood pressure, and pathologic severity of extracapillary proliferation, in addition to tissue fibrosis and sclerosis. The incidence rate of ESKD increased linearly with increase in plasma osmolarity (P < 0.05 for trend). In multivariate analyses, plasma osmolarity was an independent risk factor for ESKD (hazard ratio for each increment of 5 mOsm/kg in plasma osmolarity 1.56; 95% confidence interval 1.18-2.07) even after adjustment for potential confounders.

CONCLUSIONS

Increased plasma osmolarity was associated significantly with an increased risk of ESKD in patients with IgAN. Maintenance of plasma osmolarity by appropriate control of the balance between salt and water may contribute to kidney protection.

Biomarker prediction for membranous nephropathy prognosis by microarray analysis

AIM

This study aimed to explore biomarkers for membranous nephropathy (MN) diagnosis and to provide novel insights into the pathogenesis of this disease.

METHODS

A microarray data set, GSE73953, was used, which contained 15 immunoglobulin A nephropathy (IgAN) samples, 8 MN samples and 2 healthy controls. Pretreatments were performed for the raw data, and then, the differentially expressed genes (DEG) were screened out using the limma package. The function and pathways of these genes were demonstrated through enrichment analysis. Protein-protein interaction (PPI) network analysis was performed to uncover interactions of DEG from the protein level. MN-related genes were further selected, integrating the Comparative Toxicogenomics Database (CTD).

RESULTS

In total, 446 and 231 DEG were identified in the comparisons of MN versus control and MN versus IgAN, respectively. JUN, NFKB1, TGFB1 and PPBP were the predominant DEG, and the latter two were especially differentially expressed between the MN and IgAN groups. UBL4A and EIF4G1 were the two most important DEG for MN because they were downregulated compared with both control and IgAN groups. The above-mentioned genes were highlighted in the PPI networks and mainly enriched the ribosome- and platelet-related function/pathways.

CONCLUSION

Several potential biomarkers were identified in MN, and some of them could well distinguish the MN from IgAN. Disruption of ribosome- and platelet-related function or pathways might contribute to MN progression. EIF4F and UBL4A might be two novel biomarkers for MN prognosis. Nevertheless, more experimental validations are needed.

Secular trends in the incidence of end-stage renal disease and its risk factors in Japanese patients with immunoglobulin A nephropathy

Background

There are limited data on secular trends in the incidence of end-stage renal disease (ESRD) and frequencies of its risk factors or treatment modalities in patients with immunoglobulin A nephropathy (IgAN).

Methods

This study divided 1255 patients with IgAN into three groups according to the timing of renal biopsy: 1979-89 (n = 232), 1990-99 (n = 574) and 2000-10 (n = 449). The age-adjusted incidence rates, incidence rate ratios and 95% confidence intervals (CIs) for ESRD were calculated by the person-year method and compared using Poisson regression analysis.

Results

A total of 63 patients (5.0%) developed ESRD. The age-adjusted incidence of ESRD decreased significantly over time, i.e. 11.5 per 1000 person-years (95% CI 5.4-24.6) in 1979-89, 6.5 per 1000 person-years (95% CI 1.0-25.2) in 1990-99 and 4.2 per 1000 person-years (95% CI 1.0-17.7) in 2000-10. The proportions of patients with preserved renal function and acute-stage inflammatory histologic changes (i.e. endocapillary hypercellularity and extracapillary proliferation) at the timing of biopsy increased over time, as did the rates of prescriptions of renin-angiotensin system blockers and corticosteroids (all P for trend <0.05). The effect of acute inflammatory histologic lesions on renal prognosis was drastically reduced over time.

Conclusions

These findings suggest that early diagnosis in the acute inflammatory phase and subsequent aggressive treatment may have contributed to the significant downward trend in the incidence of ESRD in patients with IgAN over three decades.

Tonsillitis exacerbates renal injury in IgA nephropathy through promoting Th22 cells chemotaxis

BACKGROUND

Tonsillitis can promote the progression of IgA nephropathy (IgAN) by aggravating immunopathologic response. Th22 cell disorder is involved in the pathogenesis of IgAN with tonsillitis. This study was determined to explore the possible mechanism of IgAN with tonsillitis underlying Th22 cell chemotaxis response to the effect of CCL20, CCL22, and CCL27.

METHODS

This research was conducted on 65 subjects including 16 healthy controls (HC group), 5 patients with  renal carcinoma (HTC group) and 44 patients with IgAN between 2015 and 2016. According to clinical symptoms and results of throat swab culture, patients with IgAN were divided into two groups: IgAN with tonsillitis (IgAN + tonsillitis, n = 14) and IgAN patients without tonsillitis (IgAN, n = 30). Distribution of Th22 cells in IgAN patients was determined. The expression of CCL20, CCL22, and CCL27 in both peripheral blood and kidneys of IgAN patients was investigated. Severity of pathological lesions in IgAN patients was analyzed. Coculture assay and transwell assay were performed to explore the impacts of human mesangial cells (HMC) on Th22 cell chemotaxis and Th22 cell local accumulation under hemolytic streptococcus (HS) infection.

RESULTS

Th22 cell percentages in IgAN patients increased compared with healthy controls. This increased Th22 cell percentage was positively correlated with the renal lesions of IgAN patients. Correspondingly, the expression of CCL20, CCL22, and CCL27 in renal tissue increased in IgAN patients. Tonsillitis exacerbated these overrepresentations of Th22 cells and chemokines. It was found that HMC could produce CCL20, CCL22, and CCL27. The supernatant of HMC was chemotactic for Th22 cells. This activity of HMC was stimulated by HS infection, whereas treatment of anti-CCL20, anti-CCL22, and anti-CCL27 antibodies partly blocked this chemoattractant effect of HMC.

CONCLUSIONS

Tonsil infection may aggravate the renal pathological lesions of IgAN by exacerbating Th22 cell accumulation. Our data suggested a collaboration between HMC and Th22 cells in IgAN with tonsillitis underlying the effects of CCL20, CCL22, and CCL27.

Long-term follow up of pediatric immunoglobulin A nephropathy treated with tonsillectomy plus methylprednisolone pulse therapy

BACKGROUND

The aim of this study was to clarify the long-term efficacy of tonsillectomy plus methylprednisolone pulse therapy (tonsillectomy pulse therapy [TMP]) for pediatric immunoglobulin A nephropathy (IgAN). The clinical and laboratory findings as well as the prognosis for IgAN treated with TMP at long-term follow up were evaluated.

METHODS

We collected data on 33 IgAN children treated with TMP. The children were retrospectively divided into two groups. Group 1 consisted of 18 children treated with TMP as the initial therapy, and group 2 consisted of 15 children treated with TMP as rescue therapy for IgAN relapse. The clinical features, and laboratory and pathological findings, including those at first and second renal biopsy as well as at the latest follow up, were analyzed for both groups.

RESULTS

Mean urinary protein excretion, incidence of hematuria, and serum creatinine in groups 1 and 2 were all decreased significantly after TMP compared with beforehand. The percentage of glomeruli showing crescents after TMP in groups 1 and 2 was significantly lower than before TMP. At the most recent follow up, 94% of patients in group 1 and 87% in group 2 had normal urine, 6% in group 1 and 13% in group 2 had minor urinary abnormalities, and no patients in either group had active renal disease or renal insufficiency.

CONCLUSIONS

TMP is effective in ameliorating urinary abnormalities and improving the long-term outcome of pediatric IgAN both as an initial and as a rescue treatment.

IgA nephropathy and infections

In this paper we concentrate on the role of infections in IgA nephropathy both from a pathogenetic and clinic point of view. The current hypotheses as regards the role of infections in the pathogenesis of IgA nephropathy are: (a) role of particular pathogens, (b) chronic exposure to mucosal infections, (c) abnormal handling of commensal microbes (gut microbiota). We also focus on particular infections reported in association with classic IgA nephropathy (HIV, malaria, Chlamydia, Lyme disease), as well as on IgA dominant-infection-associated glomerulonephritis. This is a unique form of glomerulonephritis, where IgA deposition is dominant. It is mostly recognized in old, diabetic patients and in association with staphylococcal infection.

The efficacy of tonsillectomy on clinical remission and relapse in patients with IgA nephropathy: a randomized controlled trial

BACKGROUND

The efficacy of tonsillectomy in immunoglobulin A nephropathy (IgAN) remains controversial. The aim of the study was to conduct a randomized controlled trial to evaluate the effect of tonsillectomy in patients with IgAN.

METHODS

We randomly selected 98 patients with biopsy-proven IgA nephropathy and randomly allocated to receive tonsillectomy combined with drug therapy (Group A) or drug therapy alone (Group B). The participating patients were entered into a 4-year single-center study. Remission and relapse rate were calculated for hematuria and proteinuria using the Kaplan-Meier method.

RESULTS

No differences were found between the two groups in their baseline clinical and histological characteristics. Patients with tonsillectomy exhibited considerable improvement in the following aspects compared to those patients who did not undergo tonsillectomy: time to reach first remission (3.1 vs. 24.9 months, p < 0.001) for hematuria and (2.5 vs. 26.1 months, p < 0.001) for proteinuria, cumulative remission rate (91.8% vs. 46.9%, p < 0.001 by log-rank test) for hematuria and (95.9% vs. 51.0%, p < 0.001) for proteinuria, the duration of first remission (26.5 vs. 11.8 months, p = 0.0047) for hematuria and (23.5 vs. 10.5 months, p = 0.0012) for proteinuria, as well as lower relapse rate for hematuria and proteinuria in Group A.

CONCLUSION

Our clinical data demonstrated that tonsillectomy could be beneficial for IgAN patients, particularly by contributing to faster and longer remission, as well as reducing the frequency of possible future relapses.

The role of tonsillectomy in IgA nephropathy

The IgA nephropathy (IgAN) is a very common glomerulonephritis and can result in end-stage renal disease. From a clinical point of view, IgAN is characterised by repeated events of macrohaematuria associated with infections of the upper airways. In IgAN, the IgA released by the tonsillar lymphatic tissue into blood circulation are defective in glycosylation. These aberrant IgA can reach the glomeruli and deposit into mesangium causing an inflammation with cellular proliferation. The treatment is not yet well defined: steroids and immunosuppressive drugs are suggested in cases with a progressive disease. Tonsillectomy was proposed to reduce the infective events of upper airways and the lymphatic tissue producing undergalactosylated IgA. The experiences in literature coming from Asia report positive effects of tonsillectomy on IgAN. In patients with tonsillectomy, the renal signs improved (less haematuria and proteinuria) and the renal outcome was better (slower progression of renal damage). These were uncontrolled studies and tonsillectomy was associated with steroid and immunosuppressive treatment, so it is not possible to tell the real effect of tonsillectomy. In contrast, the European studies reported that the tonsillectomy was not associated with a better outcome of IgAN. A critical review of the subject reveals that most of the papers with positive results were uncontrolled retrospective experiences, while in a randomised controlled trial paper the advantages of tonsillectomy disappeared. In conclusion, this review, in agreement with the international guidelines, concludes that tonsillectomy does not play any role in the progression of IgAN.

The effect of renin-angiotensin system blockade on the incidence of end-stage renal disease in IgA nephropathy

BACKGROUND

The impact of renin-angiotensin system blockade (RASB) on the incidence of end-stage renal disease (ESRD) remains unclear in IgA nephropathy (IgAN).

METHODS

This study assessed associations between RASB treatment and the incidence of ESRD in IgAN using propensity score approaches. We retrospectively analyzed 1273 patients with IgAN biopsied between 1979 and 2010. Propensity scores were calculated using logistic regression. Associations between RASB and ESRD were examined using a Cox regression model adjusted by inverse probability of treatment weighted, regression, stratification and matching.

RESULTS

During follow-up (median 5.1 years), 130 patients developed ESRD. With Cox regression adjusted by inverse probability of treatment weighted, RASB use was significantly associated with a lower risk of ESRD (hazard ratio 0.58; 95 % confidence interval 0.42-0.80). Significant associations were observed for other propensity score-based approaches. In stratified analysis, a beneficial association between RASB and ESRD was observed in patients ≥35 years, with hypertension, reduced estimated glomerular filtration rate (<60 mL/min/1.73 m²), mesangial proliferation and segmental glomerulosclerosis (P for interaction <0.05), and tended to be greater in patients with proteinuria (≥1.0 g/24 h), extracapillary proliferation and receiving methylprednisolone pulse therapy (P for interaction <0.10).

CONCLUSION

Treatment with RASB was associated with a lower incidence of ESRD in the real-world practice of IgAN.

Recurrent IgA nephropathy complicated with Crohn's disease after renal transplantation

A 27-year-old man was diagnosed with IgA nephropathy and Crohn's disease. He had been diagnosed with proteinuria and hematuria since he was 20 years old. Diarrhea had been a continuing problem during the past 5 months. Neither corticosteroid therapy nor tonsillectomy was performed. Hemodialysis was required at age of 30, while the symptoms of Crohn's disease were ameliorated by an elemental diet. He received a renal transplant from his mother 4 months after starting dialysis therapy. The initial immunosuppression therapy consisted of methylprednisolone, mycofenolate mofetil, cyclosporine, and basiliximab. Eight months after transplantation, proteinuria and hematuria appeared and serum creatinine was 1.4 mg/dL. Relapse of IgA nephropathy was confirmed by the one-year protocol biopsy. He had suffered from tonsillitis at 32 months after the transplantation. Urinary protein increased to 3 g/day and serum creatinine was elevated to 2.04 mg/dL. Renal biopsy was performed 2 weeks after the urinary findings were aggravated. The cellular crescents constituted 36 % of the glomeruli. The findings of rejection were not confirmed in both biopsies. Tonsillectomy was performed thereafter. No additional immunosuppressive therapy was added. Proteinuria and hematuria disappeared at 4 and 20 months, respectively, after tonsillectomy, even when the symptoms of Crohn's disease worsened 69 months and 89 months after transplantation. A renal biopsy was performed 101 months after transplantation. Although IgA in the mesangium area was confirmed by immunohistochemical staining, no active lesion was seen. Tonsillectomy along with immunosuppressants for the graft might be an effective treatment for some patients with active recurrent IgA nephropathy.