Renal outcome after tonsillectomy plus corticosteroid pulse therapy in patients with immunoglobulin A nephropathy: results of a multicenter cohort study

Burden of corticosteroid therapy in patients with immunoglobulin A nephropathy (IgAN): a systematic literature review

BACKGROUND

Immunoglobulin A nephropathy (IgAN) is one of the most common forms of primary glomerulonephritis (GN) worldwide. While specific treatment differs regionally, treatment usually focuses on background therapy, with short-term (≤ 6 months) corticosteroids recommended as an add-on treatment for patients at high risk of progressive chronic kidney disease. Although corticosteroids can help to manage IgAN, treatment with corticosteroids may lead to undesirable adverse outcomes.

OBJECTIVE

To highlight corticosteroid treatment burden in patients with IgAN globally.

METHODS

Embase, MEDLINE, and Cochrane CENTRAL were searched for articles published in any language from January 1, 2013 to August 24, 2023. Eligible studies reported ≥ 1 outcome related to the clinical, humanistic, or economic burden of corticosteroids in patients with IgAN. Articles were independently screened by 2 reviewers. Data extraction and quality assessment were completed by 1 researcher and validated by a second. Results are reported among the number of studies with data on each outcome.

RESULTS

Of 1,024 records screened, 64 studies were included. Of 37 studies reporting treatment duration, 68% found that corticosteroids were used long-term (range: 8-24 months). In studies reporting data for long-term use (> 6 months), there were more overall AEs and serious AEs with corticosteroids than with comparator treatments (e.g., background therapy alone, tonsillectomy, placebo). Rates of metabolic AEs, Cushing's syndrome, edema and sleep disorders were also higher with long-term corticosteroids than with comparator treatments; however, most studies did not report the statistical significance of these results. Infection rates were similar between corticosteroids and comparator treatments.

CONCLUSIONS

Current guidelines recommend short-term corticosteroid treatment for patients at high risk of progression but long-term use appears to be widespread. Corticosteroids may lead to adverse outcomes and should therefore be reserved only for IgAN patients most at risk of rapid progression to end-stage kidney disease and for limited duration. Novel corticosteroid-sparing therapies are necessary to supplement the current treatment landscape.

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.

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.

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.

Histological classification of Japanese IgA nephropathy with a small number of glomeruli using Bayes' theorem

In Japan an original pathological classification of IgA nephropathy was used, while Oxford classification of IgA nephropathy was used globally. The Oxford classification requires ≥ 8 glomeruli while the Japanese classification requires ≥ 10. Ninety-nine patients diagnosed with IgA nephropathy were included. To determine the accuracy of histological staging, we calculated the posterior probability using Bayes' theorem and adopted three model of prior distribution. First, the actual staging distribution was reclassified using the beta distribution (reclassified distribution). Second a model with the same distribution (actual distribution) as the actual staging was used. Third, a model assuming that all cases are equally distributed (equal distribution) was used. The median number of collected glomeruli was 12 (8-19). There were 33 cases (33%) wherein the glomerular count was ≤ 9. When only cases with ≥ 10 glomeruli were included, the median posterior probability was 91% (74-99) (actual distribution, 90% [74-98]; equal distribution, 85% [73-96]). Even among the 33 cases with ≤ 9 glomeruli, there were approximately 7 cases in which the posterior probability was ≥ 90% for each model. Using Bayesian probabilistic analysis, it was possible to evaluate the histologic classification of IgA nephropathy, even when the number of obtained glomeruli was ≤ 9.

Evaluation of appropriate treatment for IgA nephropathy with mild proteinuria and normal renal function

BACKGROUND

Tonsillectomy and steroid pulse therapy (TSP) for immunoglobulin A nephropathy (IgAN) is frequently employed in many Japanese institutions; however, performing this invasive treatment in patients with mild IgAN is controversial. This study aimed to evaluate the appropriate treatment for IgAN patients with mild proteinuria.

METHODS

In this retrospective cohort analysis, 122 IgAN patients with mild proteinuria (0.5-1.0 g/day) and estimated glomerular filtration rate of ≥ 60 mL/min/1.73 m² were classified into three groups as follows: patients treated with TSP (n = 32), oral prednisolone (oPSL, n = 33), and conservative therapy (CONS, n = 47). The clinical and histological backgrounds, 5-year remission rates of urinary findings, and 10-year renal survival rates were analyzed.

RESULTS

The backgrounds were similar among the three groups. The remission rates of hematuria, proteinuria, and both were significantly higher for TSP and oPSL than for CONS; however, they were similar for TSP and oPSL. In the multivariate Cox regression analysis, TSP and oPSL were independent factors for the remission of urinary findings compared with CONS; however, the relapse rates of urinary abnormalities were similar among the three groups. No patient progressed to end-stage renal disease (ESRD) within 10 years. Adverse effects of corticosteroid therapy were significantly more frequent in oPSL than in TSP.

CONCLUSION

In IgAN patients with mild proteinuria and stable renal function, similar to oPSL, TSP showed higher remission rates of hematuria and/or proteinuria than CONS, and no case progressed to ESRD regardless of the treatment methods. Therefore, appropriate treatments should be carefully considered for each patient.

Long-Term Beneficial Effects of Tonsillectomy on Patients with Immunoglobulin A Nephropathy

BACKGROUND

Tonsillectomy may treat IgA nephropathy (IgAN) by reducing the levels of galactose-deficient IgA1. Therefore, we aimed to analyze the long-term effects of tonsillectomy on patients with IgAN, as an initial treatment and as a treatment at any time in their lives.

METHODS

In this retrospective cohort analysis, 1147 patients with IgAN were grouped according to whether they had undergone tonsillectomy at any time, >1 year after renal biopsy (study 1), or within 1 year after renal biopsy (study 2). The patients were propensity-score matched or divided into four groups according to their proteinuria and renal function. The 20-year renal survival rates were evaluated until serum creatinine levels doubled (primary end point) and ESKD occurred (secondary end point).

RESULTS

Patients in both studies had similar background characteristics after propensity score matching. In study 1, the renal survival rates for the primary and secondary end points were significantly higher for patients who underwent tonsillectomy at any time or >1 year after renal biopsy compared with those who did not. In study 2, the renal survival rates for the primary and secondary end points were significantly higher for patients who underwent tonsillectomy soon after renal biopsy compared with those who did not (primary end point, 98% versus 69%, P=0.001; secondary end point, 100% versus 75%, P=0.0001). A stratified analysis showed that significant treatment efficacy was observed for patients with proteinuria >1.0 g/d. Multivariate Cox regression analyses showed that tonsillectomy was associated with disease progression (hazard ratio, 0.27; P=0.04). Complications associated with tonsillectomy occurred in 8% of patients.

CONCLUSIONS

Among patients with IgAN, tonsillectomy at any time of life, or soon after renal biopsy, prevents disease progression, and the procedure is relatively safe.

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.

Tonsillar immunology in IgA nephropathy

As one of the most common types of primary glomerulonephritis, IgA nephropathy (IgAN) is often characterized by the immunoprecipitation of IgA1 in mesangial area. In clinical terms, IgA nephropathy can be treated with tonsillectomy or conservative treatment, basing on modern immunology knowledge in which the mucosa immune system (MIS), especially the widely distributed mucosa-associated lymphoid tissue (MALT) is focused accordingly In terms of basic research, IgAN has been shown correlated with multiple factors, including serum Gd-IgA1 level, IgA-IgG immunity, tonsil-associated bacteria,GADD34, CX3CR1, FOXP3 and the expression of other related intrinsic immune antibody. Therefore, it is reasonable there could be mutual correlation among IgAN-associated factors. The purpose of this study is to review the new progress on the treatment and prevention of IgAN diseases and related mechanisms of IgAN tonsils, which will be of great significance for the therapy of IgAN patients.

Clinical and histological features and therapeutic strategies for IgA nephropathy

Chronic glomerulonephritis is the second most common reason, after diabetic nephropathy, for initiation of dialysis in Japan and IgA nephropathy (IgAN) is the most prevalent form of chronic glomerulonephritis. In the half century since IgAN was initially reported, our understanding of the long-term prognosis, clinical and histological features, pathogenesis of onset and progression, risk factors for progression, and appropriate treatment under different clinical and histological conditions, has steadily increased. Strong experimental and clinical evidence, the Clinical Practice Guidelines for IgA Nephropathy in Japan, the Oxford Classification, and the Kidney Disease Improving Global Outcomes guidelines have all contributed to the appropriate treatment of IgAN. Several intensive therapies, such as tonsillectomy, steroid therapy, and their combinations, can result in clinical remission, and prevent the progression to end stage renal disease (ESRD). However, some IgAN patients still progress to ESRD even when treated with intensive therapies. In this review, we discuss the clinical and histological features of IgAN, focusing primarily on our previous reports, and our opinions on therapeutic strategies for IgAN.

Corticosteroids pulse therapy and oral corticosteroids therapy for IgA nephropathy patients with advanced chronic kidney disease: results of a multicenter, large-scale, long-term observational cohort study

Background

Corticosteroids are widely used to reduce the urine protein levels of patients with immunoglobulin A nephropathy (IgAN). However, their potential preventive effects on end-stage kidney disease (ESKD) are unclear.

Methods

We previously performed a large-scale, long-term multicenter cohort study of patients with biopsy-proven IgAN treated between 1981 and 2013 (n = 1923). Based on the results, we reported that corticosteroids pulse therapy was potentially effective for the treatment of patients with an eGFR ≥30 ml/min/1.73m² and a urine protein amount of ≥1 g/gCr. In the present study, we extracted 766 patients with chronic kidney disease (CKD), stage G3–G4 (15 ≤ estimated glomerular filtration rate [eGFR] < 60 mL/min/1.73m²) from the same cohort. We divided these patients into a steroid pulse (SP) group, oral steroid (OS) group, and no steroid (NS) group, and analyzed the risk of end-stage kidney disease (ESKD) stratified by eGFR and urine protein (UP) amounts.

Results

Over the median long-term follow-up of 70 ± 115 months, 37.1% of the patients with UP ≥1.0 g/day and 11.2% of the patients with UP < 1.0 g/day reached ESKD. Among the patients with UP ≥1 g/gCr, the SP group showed significantly better renal outcome (p < 0.001) than the OS and NS groups. In patients with UP < 1 g/gCr, there were no differences in renal survival among the treatment groups. These trends appeared even in the CKD stage G4 patients, and were also apparent in patients taking renin-angiotensin system inhibitors. The unprecedented long-term observation period in this study may have been necessary to reveal the favorable effect of corticosteroids on ESKD progression.

Conclusions

In our long-term multicenter study, Corticosteroids pulse therapy was associated with better renal outcomes in IgAN patients with higher UP values, even if their eGFR values were low.

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.

Long-term efficacy of tonsillectomy as a treatment in patients with IgA nephropathy: a meta-analysis

PURPOSE

IgA nephropathy (IgAN) is the most common glomerulonephritis worldwide and will lead some unfavorable outcomes such as end-stage renal disease. The efficacy of tonsillectomy remains controversial in both Asian and Caucasian ethnicity. Our meta-analysis was aiming at exploring its long-term efficacy and providing further evidences for clinical treatment.

METHODS

Prospective and retrospective studies that compared the rate of clinical remission and/or end-stage renal disease in IgAN patients who applied tonsillectomy were involved in our meta-analysis. The online databases we searched were PubMed, Embase, Cochrane Library, and Web of Science RESULTS: Nineteen studies with a total of 3483 participants are involved in our meta-analysis. It is found that treatment of tonsillectomy is significantly associated with a higher rate of clinical remission (15 studies, 3059 participants; pooled OR 3.30, 95 % CI 2.47-4.40). Meanwhile, tonsillectomy shows positive effect on refraining from developing end-stage renal disease (9 studies, 1804 participants; pooled OR 0.33, 95 % CI 0.16-0.69). In following two subgroup analyses, we integrate studies with more than 5 years of follow-up from clinical remission group and end-stage renal disease group. Both of them show that tonsillectomy has favorable long-term efficacy, pooled OR 3.37 (95 % CI 2.68-4.24) and 0.20 (95 % CI 0.12-0.33), respectively.

CONCLUSIONS

Long-term efficacy of tonsillectomy indicates that this treatment is helpful in inducing clinical remission and inhibiting development of end-stage renal disease in patients with IgAN and should be considered for addition into standard clinical treatment.