Significance of the duration of nephropathy for achieving clinical remission in patients with IgA nephropathy treated by tonsillectomy and steroid pulse therapy

Current treatment status of IgA nephropathy in Japan: a questionnaire survey

BACKGROUND

In 2020, the Committee of Clinical Practical Guideline for IgA Nephropathy (IgAN) revised the clinical practice guidelines. Herein, we conducted a questionnaire survey to assess the potential discrepancies between clinical practice guidelines and real-world practice in Japan.

METHODS

A web-based survey of members of the Japanese Society of Nephrology was conducted between November 15 and December 28, 2021.

RESULTS

A total of 217 members (internal physicians: 203, pediatricians: 14) responded to the questionnaire. Of these respondents, 94.0% answered that the clinical practice guidelines were referred to "always" or "often." Approximately 66.4% respondents answered that histological grade (H-Grade) derived from the "Clinical Guidelines for IgA nephropathy in Japan, 3rd version" and the "Oxford classification" were used for pathological classification. Moreover, 73.7% respondents answered that the risk grade (R-grade) derived from the "Clinical Guidelines for IgA nephropathy in Japan, 3rd version" was referred to for risk stratification. The prescription rate of renin-angiotensin system blockers increased based on urinary protein levels (> 1.0 g/day: 88.6%, 0.5-1.0 g/day: 71.0%, < 0.5 g/day: 25.0%). Similarly, the prescription rate of corticosteroids increased according to proteinuria levels (> 1.0 g/day: 77.8%, 0.5-1.0 g/day: 52.8%, < 0.5 g/day: 11.9%). The respondents emphasized on hematuria when using corticosteroids. In cases of hematuria, the indication rate for corticosteroids was higher than in those without hematuria, even if the urinary protein level was 1 g/gCr or less. Few severe infectious diseases or serious deterioration in glycemic control were reported during corticosteroid use.

CONCLUSION

Our questionnaire survey revealed real-world aspects of IgAN treatment in Japan.

Comparison of two protocols for steroid pulse therapy in patients with IgA nephropathy: a retrospective observational study

Background

Steroid pulse (SP) therapy is one of the immunosuppressive therapies for immunoglobulin A nephropathy (IgAN). Although there are various protocols of SP therapy in IgAN, the intermittent SP (ISP) and consecutive SP (CSP) protocols are prevalently performed in clinical settings. However, there is a lack of evidence of comparisons of the effects on IgAN between these two protocols.

Methods

A total of 189 patients with IgAN who had received SP therapy were included in this study. They were divided into two groups according to the SP protocols into the intermittent SP (ISP) or consecutive SP (CSP) group as follows: ISP; three-times SP therapy in alternate months, CSP; three-times SP therapy in three consecutive weeks. Kidney function, remission of urinary findings, and side effects of SP therapy were compared between the two groups. The observational period was 12 months after the initiation of SP therapy.

Results

There was no significant difference in kidney function between the two groups during the observational period. The remission rate of proteinuria and hematuria at 12 months also did not significantly differ between the two groups. Furthermore, even after the adjustment of clinical characteristics using propensity score matching, the remission rate of proteinuria and hematuria at 12 months was similar between the two groups. At 2 months, the remission rate of proteinuria was significantly higher in the CSP group than in the ISP group. There were no critical side effects in both groups.

Conclusion

The effects of SP therapy on IgAN were similar between the ISP and CSP group at 12 months although CSP therapy could remit proteinuria faster than ISP therapy.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12882-022-02791-x.

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.

Spontaneous remission in adult patients with IgA nephropathy treated with conservative therapy

Background

There are few studies describing the clinical course and spontaneous remission of IgA nephropathy (IgAN) in adult patients receiving conservative treatment.

Method

Data from 62 adult patients with biopsy-diagnosed IgAN, who received conservative treatment at least 5 years prior, were retrospectively investigated. No patients received corticosteroids, other immunosuppressants, or tonsillectomy. Remission of proteinuria and hematuria were defined as proteinuria <0.3 g/gCr and urine red blood cells (RBC) <5 / high power field (HPF) on three consecutive urinalyses obtained during an observation period of ≥6 months.

Result

Thirty-eight (61.3%) patients had remission of hematuria, 24 (38.7%) had remission of proteinuria, and 19 (30.6%) had remission of both. Remission rates increased in patients with proteinuria <0.5 g/g Cr at diagnosis. The median time to remission of hematuria was 2.8 years and that of proteinuria was 2.6 years. Patients who showed renal function decline (defined as 30% decline of estimated glomerular filtration rate [eGFR] from baseline) were older, had significantly lower eGFR, and higher proteinuria at diagnosis. Two patients with preserved renal function and normal proteinuria at diagnosis experienced renal function decline. Renal function did not decline within 3 years of diagnosis in patients with proteinuria <1 g/gCr at diagnosis.

Conclusions

Relatively high rates of spontaneous remission were observed. Remission of both hematuria and proteinuria were frequent within 3 years after diagnosis, and renal function was well preserved during this period. These data indicate that it is rational to use conservative treatment for 3 years after the diagnosis instead of aggressive treatments.

Preventive Effect of Tonsillectomy on Recurrence of Henoch-Schönlein Purpura Nephritis after Intravenous Methylprednisolone Pulse Therapy

Henoch-Schönlein purpura (HSP) is regarded as a benign and self-limiting vasculitis characterized by purpura, arthritis, and gastrointestinal symptoms; however, about one third of the patients develop HSP nephritis (HSPN), the most serious long-term complication. Since 2013, we have proposed that tonsillectomy in addition to intravenous methylprednisolone pulse therapy (IVMP) be performed in all patients with HSPN, similar to immunoglobulin A nephropathy (IgAN) patients because both diseases are considered to a share common pathogenesis. Herein, we retrospectively reviewed the clinical courses of 71 Japanese children with HSPN (34 boys; median age at diagnosis, 6.7 years; median follow-up period, 5.6 years) who had received initial treatment with IVMP (15-20 mg/kg; on 3 consecutive days/week for 3 weeks) followed by oral prednisolone (initially 1 mg/kg; tapered off within 12 months) and achieved clinical remission (i.e., disappearance of both proteinuria and hematuria). The patients were divided into two groups: 31 patients receiving tonsillectomy after IVMP between 2013 and 2017 (tonsillectomy group) and 40 patients receiving IVMP monotherapy between 2003 and 2012 (IVMP group). For the 2 years after IVMP therapy, the rate of HSPN recurrence (i.e., persistent proteinuria combined with hematuria requiring additional treatments) after clinical remission was significantly lower in the tonsillectomy group than the IVMP group (0% vs. 19%, P < 0.05). Despite the short follow-up period in the tonsillectomy group, this study provides the evidence that tonsillectomy may be beneficial for preventing recurrence of HSPN from clinical remission with IVMP therapy in Japanese children.

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.

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.

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.

Biomarkers for IgA nephropathy on the basis of multi-hit pathogenesis

IgA nephropathy (IgAN) is the most prevalent glomerular disease worldwide and is associated with a poor prognosis. Development of curative treatment strategies and approaches for early diagnosis is necessary. Renal biopsy is the gold standard for the diagnosis and assessment of disease activity. However, reliable biomarkers are needed for the noninvasive diagnosis of this disease and to more fully delineate the risk of progression. With regard to the pathogenesis of IgAN, the multi-hit hypothesis, including production of galactose-deficient IgA1 (Gd-IgA1; Hit 1), IgG or IgA autoantibodies that recognize Gd-IgA1 (Hit 2), and their subsequent immune complexes formation (Hit 3) and glomerular deposition (Hit 4), has been widely supported by many studies. Although the prognostic values of several biomarkers have been discussed, we recently developed a highly sensitive and specific diagnostic method by measuring serum levels of Gd-IgA1 and Gd-IgA1-containing immune complexes. In addition, urinary Gd-IgA1 may represent a disease-specific biomarker for IgAN. We also confirmed that there is a significant correlation between serum levels of these effector molecules and disease activity, suggesting that each can be considered a practical surrogate marker of therapeutic response. Thus, these disease-oriented specific serum and urine biomarkers may be useful for screening of potential IgAN with isolated hematuria, earlier diagnosis, disease activity, and eventually, response to treatment. In this review, we discuss these concepts, with a focus on potential clinical applications of these biomarkers.

Long-term outcomes of tonsillectomy for IgA nephropathy patients: A retrospective cohort study, two-centre analysis with the inverse probability therapy weighting method

AIM

The effect of tonsillectomy on IgA nephropathy remains controversial. The aim of this study was to compare the effect of tonsillectomy on the outcome, end stage kidney disease (ESKD) and all-cause death in IgA nephropathy patients who did and did not undergo tonsillectomy.

METHODS

All basic data were retrospectively gathered from patients who had undergone renal biopsies at two Japanese clinical centres. Two hundred and twenty-seven patients were eligible for the study, with a median age of 34 (Interquartile range (IQR): 25-43) years and median follow-up of 92 (IQR: 40-178) months. The primary endpoint was the composite outcome of the onset of ESKD and all-cause death before ESKD. We performed a Cox proportional hazard regression analysis after adjusting for patient characteristics using the inverse probability therapy weighting (IPTW) method and a Cox analysis using the Matching method. Similarly, we analyzed these outcomes in a mild cohort.

RESULTS

We were unable to find any significant advantages of tonsillectomy in either analysis (IPTW and matching, HR: 0.40 (0.12-1.36) P = 0.072 and 0.78 (0.13-4.64) P = 0.786). However, in the mild cohort analysis, our data showed that the Tonsillectomy group tended to be less likely to reach the composite outcomes than the Not Tonsillectomy group with statistical significance (hazard ratio (HR), <0.001 [CI <0.001 to <0.001, P = 0.039]).

CONCLUSION

In this study, our findings led us to conclude that performing tonsillectomy in an early and timely manner may have predisposition of less poor prognosis.

Vibration Induces BAFF Overexpression and Aberrant O-Glycosylation of IgA1 in Cultured Human Tonsillar Mononuclear Cells in IgA Nephropathy

Objective. To investigate the influence of in vitro vibratory stimulation of human tonsillar mononuclear cells (TMCs). Methods. Fourteen IgA nephropathy (IgAN) patients with chronic tonsillitis (CT) and 12 CT patients with no renal pathology were enrolled. Group A TMCs were collected after 24 hours of culture and used to determine baseline levels. TMCs in groups B, C, D, E, and F were exposed to vibratory stimulation (60 Hz) for 0 (as the control group), 1, 3, 5, and 10 minutes, respectively. Results. Baseline concentrations of B-cell-activation factor (BAFF) and IgA1, BAFF mRNA expression, and aberrant O-glycosylation IgA1 level were higher in the IgAN group as compared to that in the CT group, and all increased after vibratory stimulation. Baseline mRNA expressions of core β1,3-galactosyltransferase (C1GALT1) and core β1,3GalT-specific molecular chaperone (Cosmc) were lower in the IgAN group; the levels decreased further after vibratory stimulation. Conclusion. In patients with IgAN, vibratory stimulation of TMCs appears to induce IgA1 secretion through activation of BAFF release and to aberrant O-glycosylation IgA1 by suppressing C1GALT1 and Cosmc expression. In vitro vibratory stimulation of human TMCs mimics the vibratory simulation of palatine tonsils produced by vocal cords during phonation.

Prominent hyperplasia of renin-producing juxtaglomerular apparatus after chronic and complete blockade of the renin-angiotensin system in adult IgA nephropathy

Juxtaglomerular apparatus (JGA) hyperplasia rarely happened in renal biopsy and has been controversial clinically, because synthesis and secretion of renin were susceptible to the effect of clinical condition and medication. Here we present the case of a 39-year-old who got JGA hyperplasia of IgA nephropathy (IgAN) after long-term inhibition of the renin-angiotensin system (RAS) with an angiotensin receptor blocker (ARB), and a direct renin inhibitor (DRI) in combination with a diuretic. He was diagnosed with IgAN in his first renal biopsy, and was treated with supra-maximal dosages of ARB, DRI and a diuretic. In the second biopsy, because of the massive proteinuria and occurrence of steroid-induced diabetes, it was revealed that the area and the number of JGA cells were strikingly increased in observed glomeruli. Immunohistopathologically, the both specimens were stained by human renin antibody. The hyperplastic JG cells contained a large amount of renin granules. Putative renin granules were observed in some interstitial cells adjacent to an afferent arteriole by electron microscopy. The increasing response of renin granules co-localized in prominent JGA hyperplasia should be worried while physicians treat hypertensive patients with potent RAS inhibitors and diuretics even though they have diabetes. This is the first report showing a clinical course of forming prominent JGA hyperplasia directly after a full combination of RAS inhibitors and diuretics in adult IgA nephropathy.

Significance of tonsillectomy combined with steroid pulse therapy for IgA nephropathy with mild proteinuria

Background

Medical intervention for patients with IgA nephropathy and mild proteinuria (<1.0 g/day) is controversial, and the effectiveness of tonsillectomy plus steroid pulse therapy (TSP) for such patients remains obscure.

Methods

Among 323 patients in our multicenter cohort study, 79 who had mild proteinuria (0.4–1.0 g/day) at diagnosis were eligible to participate in this study. We compared the clinicopathological findings at diagnosis, a decline in renal function defined as a 50 or 100 % increase in serum creatinine (sCr) and clinical remission (CR) defined as the disappearance of hematuria and proteinuria (<0.3 g/day) among groups given TSP (n = 46), steroid therapy (ST) (n = 9), and non-ST (n = 24). Factors contributing to CR were also evaluated using multivariate analysis.

Results

Background factors at diagnosis including age, ratio (%) of patients with hypertension, sCr, proteinuria, and histological severity did not significantly differ among the groups. Only two patients each in the TSP (4.3 %) and non-ST (8.3 %) groups achieved a 50 % increase in sCr during a mean follow–up period of 4.7 years. At the final observation, 71.7, 44.4, and 41.7 % of patients in the TSP, ST, and non-ST groups, respectively, achieved CR (p = 0.032). Cox proportional hazards models revealed that TSP led to CR more effectively than non-TSP by a factor of about threefold (hazard ratio, 2.74; p = 0.008).

Conclusion

TSP therapy has potential for inducing CR in patients with IgAN and mild proteinuria (<1.0 g/day).

Renal biopsy findings and clinical indicators of patients with hematuria without overt proteinuria

Background

Whether to perform a renal biopsy for isolated hematuria remains a matter of controversy. We performed renal biopsy in hematuria without overt proteinuria patients and reported the proportion of glomerulonephritis, pathological activities, and statistical analysis of indicators associated with glomerulonephritis.

Methods

Among 203 patients who underwent renal biopsy in Okubo Hospital, Japan, between January 2008 and October 2013, we identified 56 patients who fulfilled the criteria: (1) urine dipstick examination shows equal to or greater than ± blood on three or more visits, (2) proteinuria <0.3 g/day (g/g Cr), (3) eGFR ≧60 ml/min/1.73 m², and (4) no current medication for renal disease. We investigated biopsy findings and compared the clinical indicators in the IgA nephropathy (IgAN) and non-IgAN group.

Results

The pathological diagnosis was IgAN in 35 cases (62 %), thin basement membrane disease (TBMD) in 7 (13 %), minor glomerular abnormality (MGA) in 6 (11 %), glomerular basement membrane (GBM) abnormality in 5 (9 %), and others in 3 (5 %). The histological grade of IgAN was I in 90 % and II in 10; 31 % of patients had some crescentic lesions. Comparisons between the IgAN and non-IgAN group revealed significant differences in age of onset (26 ± 13 vs. 34 ± 17 years, p = 0.04), serum IgA (340 ± 114 vs. 220 ± 101 mg/dl, p < 0.01), proteinuria (0.08 [0–0.25] vs. 0 [0–0.23] g/day [g/gCr], p < 0.01), and the presence of poikilocytes (40 vs. 10 %, p = 0.02).

Conclusions

The proportion of IgAN in hematuria without overt proteinuria was high and the pathological activities were variable. Patients with hematuria without overt proteinuria should continue their medical follow-up and the best timing of biopsy may be controversial for these patients who have multiple risk factors of IgAN.

Impact of the new risk stratification in the 2011 Japanese Society of Nephrology clinical guidelines for IgA nephropathy on incidence of early clinical remission with tonsillectomy plus steroid pulse therapy

BACKGROUND

In 2011, the Japanese Society of Nephrology (JSN) published new clinical guidelines for IgA nephropathy (IgAN) with a new risk stratification based on clinical and histological severity. For classification, patients are divided into four groups (low, medium, high, and very high risk). However, differences in responsiveness to each treatment among different groups remain unclear. We evaluate the responsiveness of tonsillectomy plus steroid pulse (TSP) therapy using the new risk stratification.

METHODS

We retrospectively reviewed 111 IgAN patients with TSP therapy between January 2003 and January 2013. Study patients were divided into three groups [low- (n = 40), medium- (n = 43) and high-/very high-risk group (n = 28)]. The primary outcome was clinical remission (CR). The observation period was 1 year following tonsillectomy.

RESULTS

57 out of 111 patients (51.4 %) reached CR. The CR incidence was 70.0, 41.9 and 39.3 % (the low-, the medium- and the high-/very high-risk group, respectively). The incidence of CR was significantly higher in the low-risk group (P = 0.013). In a multivariate logistic regression analysis, both the medium- and the high-/very high-risk group showed significantly lower incidence of inducing CR than the low-risk group [(odds ratio 0.324; 95 % confidence interval 0.106-0.939, P = 0.041) (odds ratio 0.239; 95 % confidence interval 0.058-0.910, P = 0.040), respectively].

CONCLUSIONS

The new risk stratification in the 2011 JSN clinical guidelines for IgAN had a positive impact on early CR of TSP therapy.

Effect of tonsillectomy and its timing on renal outcomes in Caucasian IgA nephropathy patients

PURPOSE

The role of tonsillectomy in the treatment of IgA nephropathy in Caucasian patients is controversial.

METHODS

A retrospective cohort study was conducted in 264 patients with biopsy-proven primary IgA nephropathy to examine the association between tonsillectomy and long-term renal survival, defined as the incidence of estimated glomerular filtration rates (eGFRs) of ≤30 ml/min/1.73 m(2) or end-stage renal disease (the composite of initiation of dialysis treatment or renal transplantation). The association of tonsillectomy with renal end-points was examined using the Kaplan-Meier method and Cox models.

RESULTS

One-hundred and sixty-six patients did not undergo tonsillectomy (Group I, follow-up 130 ± 101 months) and 98 patients underwent tonsillectomy (Group II, follow-up 170 ± 124 months). The mean renal survival time was significantly longer for both end-points between those patients who underwent tonsillectomy (Group II) versus patients without tonsillectomy (Group I) (p < 0.001 and p = 0.005). The mean renal survival time was significantly longer for both end-points between those patients who had macrohaematuric episodes versus patients who had no macrohaematuric episodes (p = 0.035 and p = 0.019). Tonsillectomy, baseline eGFR and 24-h proteinuria were independent risk factors for both renal end-points.

CONCLUSION

Tonsillectomy may delay the progression of IgA nephropathy mainly in IgA nephropathy patients with macrohaematuria. Prospective investigation of the protective role of tonsillectomy in Caucasian patients is needed.

Serum levels of galactose-deficient immunoglobulin (Ig) A1 and related immune complex are associated with disease activity of IgA nephropathy

Background

The primary abnormal manifestation in immunoglobulin A nephropathy (IgAN) is recurring bouts of hematuria with or without proteinuria. Although immunohistochemical analysis of renal biopsy tissue remains the gold standard not only for diagnosis but also for evaluating the activity of IgAN, new sensitive and reasonably specific noninvasive tests are emerging to guide therapeutic strategy applicable to all stages of IgAN. The present study examined serum levels of galactose-deficient IgA1 (Gd-IgA1) and its immune complex (IgA/IgG-IC) as noninvasive markers for the disease activity.

Methods

We enrolled 50 IgAN patients (male 40 %, median age 37 years) showing complete or partial clinical remission after steroid pulse therapy with tonsillectomy (TSP) whose clinical data and serum could be followed up for 3–5 years.

Results

Cross-sectional analysis revealed that the degree of hematuria and proteinuria were significantly associated with levels of Gd-IgA1 and levels of IgA/IgG-IC. Longitudinal analysis further showed that from the group of 44 patients with heavy hematuria before TSP, 31 patients showed complete disappearance of hematuria (group A), but the remaining patients did not (group B). Although the levels of Gd-IgA1 and IgA/IgG-IC in the two groups before TSP were similar, percentage decrease of Gd-IgA1 and IgA/IgG-IC levels in group A was significantly higher than in group B.

Conclusion

Disease activity of IgAN assessed by hematuria and proteinuria correlated with serum levels and changes of Gd-IgA1 and IgA/IgG-IC. These new noninvasive disease activity markers can be useful for future activity scoring system and guiding therapeutic approaches.

Estimated glomerular filtration rate and daily amount of urinary protein predict the clinical remission rate of tonsillectomy plus steroid pulse therapy for IgA nephropathy

Background

This retrospective study was designed to estimate the clinical remission (CR) rate of tonsillectomy plus steroid pulse (TSP) therapy in patients with IgA nephropathy.

Methods

Based on 292 of 302 patients with IgA nephropathy treated at 11 Japanese hospitals, we constructed heat maps of the CR rate at 1 year after TSP with the estimated glomerular filtration rate (eGFR), grade of hematuria, pathological grade, number of years from diagnosis until TSP, and age at diagnosis on the vertical axis and the daily amount of urinary protein (urinary protein) on the horizontal axis. We compared subgroups usinge Student’s t test, the chi-square test with Yates correction, or Fisher’s exact probability test.

Results

The first heat map of eGFR and urinary protein showed that the CR rate was 71 % (CR vs. non-CR, 96 vs. 40) in patients with eGFR greater than 30 ml/min/1.73 m² and 0.3–1.09 g/day of urinary protein. However, the CR rate in patients with more than 1.50 g/day of urinary protein was approximately 30 %. The second heat map of grade of hematuria and urinary protein revealed that the CR rate is 72 % (CR vs. non-CR, 93 vs. 37) in patients with more than 1+ hematuria and 0.3–1.09 g/day of urinary protein; however, it was 28.6 % in patients with no hematuria. The third heat map of pathological grade and urinary protein demonstrated that the highest CR rate was 83 % (CR vs. non-CR, 52 vs. 11) in patients with pathological grade I or II disease and less than 1.09 g/day of urinary protein, as opposed to 22 % (CR vs. non-CR, 9 vs. 32) in patients with pathological grade III or IV disease and more than 2.0 g/day of urinary protein. The fourth heat map of the number of years from diagnosis until TSP and urinary protein revealed that the former did not influence the CR rate in patients with less than 1.09 g/day of urinary protein. However, in patients with more than 1.10 g/day of urinary protein, the CR rate of the subgroup with less than 6 years was 43 % (CR vs. non-CR; 23 vs. 54) compared to 23 % (CR vs. non-CR, 11 vs. 48; P = 0.01) in the subgroup with more than 6 years. The fifth heat map of age at diagnosis and urinary protein showed that the CR rate is approximately 72 % (CR vs. non-CR, 73 vs. 28) in patients older than 19 years at diagnosis with 0.3–1.09 g/day of urinary protein.

Conclusions

The daily amount of urinary protein is an important predictor of the CR rate after TSP in IgA nephropathy patients. Heat maps are useful tools for predicting the CR rate associated with TSP.

Primary glomerulonephritis: A review of important recent discoveries

The publication of the Kidney Disease: Improving Global Outcomes (KDIGO) guidelines on the treatment of glomerular diseases in 2012 marked a milestone in this field, as it is the first time that comprehensive guidelines are provided for such disease entities. The current review focuses on major findings, both pathogenesis related and clinical, in the primary glomerulonephritis that have been made after the guidelines came into effect.

Comparison between consecutive and intermittent steroid pulse therapy combined with tonsillectomy for clinical remission of IgA nephropathy

BACKGROUND

In recent years, tonsillectomy and steroid pulse (TSP) therapy have been widely performed in Japan. However, there is no consensus about the treatment protocol and indication.

METHODS

In this retrospective analysis, we compared patients who received tonsillectomy plus intermittent steroid pulse (SP) therapy three times in 6 months (ISP group, n = 44) with patients who received tonsillectomy plus 3 weeks of consecutive SP therapy (CSP group, n = 46) within 1 year after renal biopsy. These two different protocols were performed at two different institutions. We analyzed the clinical and histological background and clinical remission (CR), defined as disappearance of urine abnormalities at 18 months after starting treatment.

RESULTS

Before treatment, there was no significant difference in the clinical findings except for sex between the two groups. In ISP group and CSP group, mean estimated glomerular filtration rate was 82.1 ± 20.9 and 85.9 ± 19.1 ml/min/1.73 m(2), median proteinuria was 0.55 and 0.56 g/day, and median urinary red blood cells were 20 (10-20) and 20 (6-30)/high power filed. The histological (H) grade was lower in the CSP than the ISP group (p = 0.022). The remission rate of proteinuria, hematuria, and rate of CR by the Kaplan-Meier method and logrank test were significantly higher in the CSP group than in the ISP group (CSP vs. ISP group; proteinuria: 97.8 vs. 77.3 %, p < 0.001, hematuria: 97.8 vs. 75.0 %, p = 0.005, CR: 95.6 vs. 63.6 %, p < 0.001). In the Cox proportional hazard model (forced entry), SP protocol and proteinuria before treatment were significantly associated with CR [SP protocol: hazard ratio (HR) 2.50, 95 % confidence interval (CI) 1.46-4.30, p = 0.001, proteinuria: HR 0.81, 95 % CI 0.68-0.96, p = 0.013)]. However H-grade was associated with remission of proteinuria (H-grade: hazard ratio (HR) 0.56, 95 % confidence interval (CI) 0.37-0.85, p = 0.006), and this result meant histological bias affected the remission of proteinuria.

CONCLUSIONS

The difference of the protocol of TSP therapy may have some effect on the CR of IgAN, though the histological bias was observed in this study. The appropriate protocol and indication of TSP therapy must be analyzed and determined in the randomized controlled trial.