Efficacy and safety of mycophenolate mofetil in patients with IgA nephropathy: an update meta-analysis

Treatment of Patients with IgA Nephropathy: Evaluation of the Safety and Efficacy of Mycophenolate Mofetil

INTRODUCTION AND AIM

Immunoglobulin A nephropathy (IgAN), characterized by aberrant IgA immune complex deposition, is the most prevalent primary glomerular disease and the main cause of end-stage renal disease, causing a significant physical and psychological burden on people worldwide. Conventional therapeutic approaches, such as renin-angiotensin-aldosterone system inhibitors and corticosteroids, may not achieve sufficient effectiveness and may produce major side events in the past. The previous data in Asian populations indicated that mycophenolate mofetil (MMF) might significantly advance the development of a new therapy strategy for IgAN. The effectiveness and safety of MMF in patients with IgAN will be investigated in this study.

METHODS

A literature search was conducted on June 30th, 2023, by searching the following databases: PubMed and the Cochrane Library according to predefined criteria. To investigate the renoprotective benefits and safety of MMF, statistical analyses were performed using Cochrane's Review Manager Version 5.3.

RESULTS

The meta-analysis included nine randomized controlled studies that fulfilled the inclusion criterion. In the Asian population, the results revealed a substantial difference in remission rates between the MMF group and the control group (OR: 2.53, 95% CI: 1.02, 6.30, P = 0.05). MMF can increase the rate of decrease in proteinuria in IgAN patients when compared with controls in Asians (OR: 7.34, 95% CI: 2.69, 20.08, P = 0.0001), and MMF can reduce the urinary protein in patients with IgAN in Asians (WMD: -0.61, 95% CI: -1.15, -0.08, P = 0.02). Interestingly, these studies on Asians were conducted in China. However, the differences in remission rate, rate of decrease in proteinuria, and urinary protein reduction between the MMF group and control group were not found in overall populations and in the Caucasian population. The differences in complete remission rate, partial remission rate, serum creatinine (SCr) doubling rate, rate of 50% increase in SCr, and rate of need for renal replacement treatment between the MMF group and control group were not found in Asians, Caucasians, and overall populations. The difference in the rate of side effects between the MMF group and the control group was not found.

CONCLUSION

MMF protects renal function and is a safe medication for treating Chinese IgAN patients. MMF might significantly advance the development of a new therapy strategy for IgAN in the Chinese population.

The steroid-sparing effects of a mycophenolate mofetil-based regimen in the management of immunoglobulin A nephropathy in patients with histologically active lesions: A comparison with a control cohort receiving conventional therapy

INTRODUCTION

While the use of different immunosuppressants has been investigated in immunoglobulin A nephropathy, further investigation is needed to assess the effect of a regimen of mycophenolate mofetil combined with a short course of glucocorticosteroids in the subset of patients with histologically active features. We compared the efficacy and safety of a combined regimen of mycophenolate mofetil and glucocorticosteroids to a conventional regimen of glucocorticosteroids alone in patients with immunoglobulin A nephropathy who have active lesions and major urinary abnormalities.

METHODS

This retrospective study involved 30 immunoglobulin A nephropathy patients with active histological lesions, 15 of whom were treated with both mycophenolate mofetil 2 g/day for 6 months and 3 pulses of 15 mg/kg methylprednisolone, followed by a short tapering schedule of oral prednisone. The control group was made up of the remaining 15 clinically- and histologically-matched patients treated with glucocorticosteroids alone according to a validated schedule, i.e., 1 g of methylprednisolone given intravenously for 3 consecutive days, followed by oral prednisone 0.5 mg/kg every other day for 6 months. At diagnosis, all patients had urinary protein excretion > 1 g/24 h and microscopic hematuria.

RESULTS

At the end of the first year of follow-up (30 patients) and after 5 years (17 patients), there were no differences between the two groups in terms of urinary abnormalities and functional parameters. Both regimens achieved a statistically significant decrease in 24-h urinary protein excretion (p < 0.001) and a reduction of microscopic hematuria. However, the mycophenolate mofetil-based regimen allowed a cumulative sparing dose of 6 g of glucocorticosteroids.

CONCLUSION

In this single center study on immunoglobulin A nephropathy patients with active lesions and major urinary abnormalities and at increased risk of glucocorticosteroid-related complications, a mycophenolate mofetil-based regimen demonstrated similar outcomes in terms of complete response and relapse (at 1 and 5 years) compared to a conventional glucocorticosteroid-based protocol, while achieving a consistent reduction of glucocorticosteroid cumulative dose.

Immunoglobulin A vasculitis nephritis: Current understanding of pathogenesis and treatment

The clinical spectrum of immunoglobulin A vasculitis nephritis (IgAVN) ranges from the relatively common transitory microscopic hematuria and/or low-grade proteinuria to nephritic or nephrotic syndrome, rapidly progressive glomerulonephritis, or even renal failure. Clinical and experimental studies have shown a multifactor pathogenesis: Infection triggers, impaired glycosylation of IgA1, complement activation, Toll-like-receptor activation and B cell proliferation. This knowledge can identify IgAVN patients at a greater risk for adverse outcome and increase the evidence for treatment recommendations.

Management of IgA Vasculitis with Nephritis

Immunoglobulin A (IgA) vasculitis (IgAV), previously called Henoch-Schönlein purpura, is characterized by IgA-dominant immune deposits affecting small vessels and often involves the skin, gastrointestinal tract, joints, and kidneys. IgAV is the most common cause of systemic vasculitis in children. The long-term prognosis is dependent on renal involvement: IgAV with nephritis (IgAVN) can progress to renal failure. IgAVN is an inflammatory disease, providing a rationale for the use of corticosteroids. However, data supporting the use of corticosteroids in patients with established IgAVN of any severity remain limited, although most clinicians use them. Even in patients with severe forms of IgAVN, methylprednisolone pulses added to oral corticosteroids appears to improve renal outcomes. Considering the multihit hypothesis for the pathogenesis of IgAVN, involving many other immune agents, there is a strong rationale for the use of other immunosuppressive drugs in patients with IgAVN, including mycophenolic acid, cyclophosphamide, rituximab, calcineurin inhibitors, and complement inhibitors. Thus, these immunosuppressive treatments have also been evaluated in IgAVN, usually in corticosteroid-dependent or corticosteroid-resistant forms and in small retrospective studies. However, their efficacy has not been proven. Thus, the risk of progression to renal failure and the ongoing debate about the best management of IgAVN justifies the interest in investigating and identifying treatments that can potentially preserve renal function in patients with IgAVN. This review reports on the efficacy of the different drugs currently used for the treatment of IgAVN in adults and children.

Is IgA nephropathy the same disease in different parts of the world?

Since it was first described in 1968, immunoglobulin A nephropathy (IgAN) is understood to be the most common form of glomerulonephritis worldwide. The diagnosis of IgAN depends on the presence of dominant mesangial IgA1 deposition by renal biopsy. To date, a wide spectrum of clinical and pathologic features of IgAN have been observed, implying that IgAN might not be the same disease across the world. Here, we review the characteristics of IgAN from perspectives of epidemiology, clinical-pathological patterns, disease pathogenesis, and treatment response across different ethnic populations. Overall, IgAN is most prevalent in Asians, followed by Caucasians, and relatively rare in Africans. More severe clinical presentation and higher risk of disease progression have been reported in Asians than Europeans. Moreover, active lesions, such as endocapillary hypercellularity and crescents, are more commonly reported in Asians than Europeans. Response to corticosteroid/immunosuppression therapy is variably reported, with greater apparent efficacy reported in Asian than European studies. Although a multi-hit hypothesis has been suggested for IgAN, the relative importance of each "hit" may vary in different ethnic populations and this variation underlies the differences in presentation of IgAN. In the future, a better understanding of pathogenic pathways operating in different ethnic populations may help provide better biomarkers of disease and more precise targeting of treatment strategies for IgAN.

Low-Dose Corticosteroid Combined With Mycophenolate Mofetil for IgA Nephropathy With Stage 3 or 4 CKD: A Retrospective Cohort Study

PURPOSE

This study assessed the long-term (10-year) tolerability and efficacy of a low-dose corticosteroid combined with mycophenolate mofetil (CS + MMF) in the treatment of immunoglobulin A nephropathy (IgAN) with stage 3/4 chronic kidney disease and proteinuria in clinical practice in China.

METHODS

Data from patients with biopsy-proven IgAN, stage 3/4 chronic kidney disease (estimated glomerular filtration rate 15-59 mL/min/1.73 m²), and proteinuria (urinary protein excretion ≥1.0 g/d) and who were treated with uncontrolled supportive care (USC), CS, or CS + MMF between January 2008 and December 2017 were included. The primary end point was the prevalence of the composite outcome of any of the following conditions: a reduction in estimated glomerular filtration rate of ≥50%, end-stage renal disease, and death.

FINDINGS

Of the 120 enrolled patients, 44, 25, and 51 were treated with USC, CS, and CS + MMF, respectively. The median follow-up time was 40.1 months (IQR, 29.1-67.8 months). The prevalences of the composite outcome were 63.6%, 56.0%, and 19.6%, respectively (P < 0.001). The cumulative 5-year renal function-preservation rates were 48.1%, 51.4%, and 83.7%. After adjustment for covariates, the prevalence of the composite outcome was significantly decreased with CS + MMF (HR = 0.094; 95% CI, 0.026-0.335; P < 0.001), but not with CS (HR = 0.749; 95% CI, 0.354-1.583; P = 0.449), compared with USC. However, 4 patients in the CS + MMF group died, of whom 3 had severe pneumonia.

IMPLICATIONS

CS + MMF may have more promising efficacy than USC or CS in renal-function preservation in patients with IgAN and chronic kidney disease in the Chinese population. However, attention should be paid to the increased risk for death due to severe pneumonia.

[Efficacy and safety of mycophenolate mofetil versus cyclophosphamide in the treatment of Henoch-Schönlein purpura nephritis with nephrotic-range proteinuria in children: a prospective randomized controlled trial]

OBJECTIVE

To study the efficacy and safety of mycophenolate mofetil (MMF) versus cyclophosphamide (CTX) in the treatment of children with Henoch-Schönlein purpura nephritis (HSPN) and nephrotic-range proteinuria.

METHODS

A prospective clinical trial was conducted in 68 pediatric patients who were admitted to the Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics and who were diagnosed with HSPN and nephrotic-range proteinuria from August 2016 to November 2019. The patients were randomly divided into two groups:MMF treatment (n=33) and CTX treatment (n=35). The two groups were compared in terms of complete remission rate, response rate (complete remission + partial remission), urinary protein clearance time, and adverse events.

RESULTS

At months 3, 6, and 12 of treatment, there was no significant difference in the complete remission rate and the response rate between the MMF treament and CTX treatment groups (P > 0.05). There was also no significant difference between the two groups in the urinary protein clearance time and the incidence rate of adverse events (P > 0.05).

CONCLUSIONS

MMF and CTX have similar efficacy and safety in the treatment of HSPN children with nephrotic-range proteinuria.

[Efficacy and safety of mycophenolate mofetil versus cyclophosphamide in the treatment of Henoch-Schönlein purpura nephritis with nephrotic-range proteinuria in children: a prospective randomized controlled trial]

OBJECTIVE

To study the efficacy and safety of mycophenolate mofetil (MMF) versus cyclophosphamide (CTX) in the treatment of children with Henoch-Schönlein purpura nephritis (HSPN) and nephrotic-range proteinuria.

METHODS

A prospective clinical trial was conducted in 68 pediatric patients who were admitted to the Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics and who were diagnosed with HSPN and nephrotic-range proteinuria from August 2016 to November 2019. The patients were randomly divided into two groups:MMF treatment (n=33) and CTX treatment (n=35). The two groups were compared in terms of complete remission rate, response rate (complete remission + partial remission), urinary protein clearance time, and adverse events.

RESULTS

At months 3, 6, and 12 of treatment, there was no significant difference in the complete remission rate and the response rate between the MMF treament and CTX treatment groups (P > 0.05). There was also no significant difference between the two groups in the urinary protein clearance time and the incidence rate of adverse events (P > 0.05).

CONCLUSIONS

MMF and CTX have similar efficacy and safety in the treatment of HSPN children with nephrotic-range proteinuria.

Efficacy and safety of immunosuppressive therapies in the treatment of high-risk IgA nephropathy: A network meta-analysis

BACKGROUND

IgA nephropathy (IgAN) is one of the significant contributing factors of end-stage renal disease (ESRD). It is reported that over half of patients with IgAN accompany multiple high-risk factors, which increase the risk of ESRD progression. Studies have shown that immunosuppressive agents were beneficial in high-risk IgAN, but the efficacy and safety have not been fully demonstrated yet. The present study aims to elucidate the efficacy of commonly used immunosuppressants in high-risk IgAN and their relative safety profiles via a network meta-analysis strategy.

METHODS

Randomized controlled trials (RCTs) eligible for this network meta-analysis were included to evaluate the efficacy and safety of different immunosuppressants for high-risk IgAN. Main outcomes and measures include incidence of renal composite end point, the rate of total remission, adverse events, and proteinuria. Besides, subgroup analysis and cluster analysis were carried out.

RESULTS

This network meta-analysis of 37 RCTs involving 3012 participants found that Mycophenolate mofetil (MMF) combined with corticosteroids (CS) was superior to other interventions in end point events and proteinuria. Cyclosporine A (CsA) plus CS was the best option for clinical remission rate, and supportive care (SC) was the safest treatment. Cluster analysis showed that MMF+CS and Leflunomide (LEF)+CS were best protocols in efficacy and safety. Subgroup analysis indicated the best benefits of MMF were presented among the Asian population, and the benefits increased with the increase of follow-up duration. The effect of Cyclophosphamide (CTX) +CS on crescent IgAN was better than that of other risk factors. Moreover, the increasing follow-up duration was negatively associated with the effect.

CONCLUSIONS

MMF+CS and LEF+CS appear to serve as the best choice for treating high-risk IgAN than other immunosuppressive therapies.

IgA Nephropathy: An Interesting Autoimmune Kidney Disease

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerulonephritis worldwide. It is a leading cause of chronic kidney disease and progresses to end-stage kidney disease in up to 40% of patients about 20 years after diagnosis. Additionally, IgAN is associated with significant mortality. The diagnosis currently necessitates a kidney biopsy, as no biomarker sufficiently specific and sensitive is available to supplant the procedure. Patients display significant heterogeneity in the epidemiology, clinical manifestations, renal progression, and long-term outcomes across diverse racial and ethnic populations. Recent advances in understanding the underlying pathophysiology of the disease have led to the proposal of a four-hit hypothesis supporting an autoimmune process. To date, there is no disease-specific treatment but, with a better understanding of the disease pathogenesis, new therapeutic approaches are currently being tested in clinical trials. In this review, we examine the multiple facets and most recent advances of this interesting disease.

Efficacy and Safety of Immunosuppressive Monotherapy Agents for IgA Nephropathy: A Network Meta-Analysis

Background: The efficacy and safety of immunosuppressive monotherapy agents were evaluated for immunoglobulin A nephropathy (IgAN) using a network meta-analysis approach. Methods: Randomized controlled trials (RCTs) published prior to October 1, 2019, using immunosuppressive agents for treating IgAN, were systematically searched in PubMed, Embase, Cochrane Library, and Web of Science databases. Relative risks (RRs) or standard mean differences with 95% confidence intervals (CIs) were estimated using the random-effects model. The primary outcomes were clinical remission, end-stage renal disease (ESRD), and serious adverse events (SAEs). The secondary outcomes were urinary protein excretion and serum creatinine. Results: Twenty-five RCTs with 2,005 participants were deemed eligible. Six medications were evaluated: corticosteroids, mycophenolate mofetil (MMF), tacrolimus (TAC), cyclosporine, leflunomide, and hydroxychloroquine (HCQ). Steroids (RR 1.50, 95% CI 1.17-1.93), MMF (RR 2.05, 95% CI 1.15-3.65), TAC (RR 3.67, 95% CI 1.06-12.63), and HCQ (RR 3.25, 95% CI 1.05-10.09) significantly improved clinical remission rates compared to supportive care alone. Only steroids reduced the risk of ESRD (RR 0.35, 95% CI 0.12-0.98); however, there were significantly more SAEs than in the control group (RR 2.90, 95% CI 1.37-6.13). No significantly different effects in serum creatinine levels were found among the therapies. MMF showed no significant improvement in remission when excluding studies with a follow-up of fewer than 2 years in the sensitivity analysis (RR 1.41, 95% CI 0.40-4.92). The effect of TAC in the decrease of proteinuria was reversed after discontinuing medication for 3 months; the long-term effects of HCQ could not be evaluated due to the short follow-up duration. Conclusion: Corticosteroids might induce remission and increase renal survival in IgAN; however, adverse reactions should be taken into consideration. MMF, TAC, and HCQ might improve the remission of proteinuria when treating IgAN, but showed no superiority compared to steroids, and the long-term effects require further study.

A Personalized Update on IgA Nephropathy: A New Vision and New Future Challenges

IgA nephropathy (IgAN) is the most common primary glomerulonephritis in the world among patients undergoing renal biopsy. Approximately 30% of patients with IgAN develop end-stage kidney disease 20 years after renal biopsy. It is a glomerulopathy with a very broad clinical presentation, making it difficult to stratify and treat. IgAN is characterized by dysregulation of the immune system, which causes an abnormal synthesis of IgA1 that is deglycosylated causing its mesangial deposition. IgAN pathogenesis is incompletely understood; the current multi-hit hypothesis of IgAN pathogenesis does not explain the range of glomerular inflammation and renal injury associated with mesangial IgA deposition. Although associations between IgAN and glomerular and circulating markers of complement activation are established, the mechanism of complement activation and contribution to glomerular inflammation and injury are not defined. On the other hand, the renal-gut connection can also play an important role in the pathogenesis of IgAN with possible therapeutic implications. In order to standardize the histological findings, the Oxford Classification has allowed clarifying renal lesions that confer potential risk of progression. Currently, except for the blockade of the renin-angiotensin-aldosterone system, no other therapies are available in clinical setting for the treatment of IgAN, although the range of new drugs under investigation is extensive. The incorporation in the next trials of clinical parameters such as the amount of hematuria and histological lesions may allow more personalized therapeutic approaches. To summarize, in recent years, several important efforts have taken place in the understanding of IgAN, but still, further studies are warranted to elucidate the best therapeutic strategies according to the risk to improve the prognosis of this entity.

[Efficacy and safety of steroid combined with immunosuppressants in the treatment of primary IgA nephropathy in children: a Meta analysis]

OBJECTIVE

To systematically evaluate the efficacy and safety of steroid combined with immunosuppressants in the treatment of primary IgA nephropathy in children.

METHODS

English and Chinese electronic databases were searched to include the studies on the efficacy and safety of steroid combined with immunosuppressants versus steroid alone in the treatment of primary IgA nephropathy in children. Outcome measures included proteinuria remission rate, urinary protein quantification, incidence of adverse events, estimated glomerular filtration rate, and incidence of renal dysfunction. Review Manager 5.3 software was used for data analysis.

RESULTS

A total of 7 studies with 381 children were included. The children had moderate to severe proteinuria. The Meta analysis showed that compared with the steroid alone group, the steroid combined with immunosuppressants group achieved a significantly higher rate of proteinuria remission (RR=1.36, 95%CI: 1.19-1.55, P<0.001) and significantly lower urinary protein quantification (SMD=-0.82, 95%CI: -1.23 to -0.41, P<0.001). There was no significant difference in the incidence rate of adverse events between the two groups (RR=1.28, 95%CI: 0.92-1.77, P=0.14).

CONCLUSIONS

The current evidence shows that for children with primary IgA nephropathy who have moderate to severe proteinuria, steroid combined with immunosuppressants has a better effect than steroid alone and does not increase the incidence rate of adverse events.

[Efficacy and safety of steroid combined with immunosuppressants in the treatment of primary IgA nephropathy in children: a Meta analysis]

OBJECTIVE

To systematically evaluate the efficacy and safety of steroid combined with immunosuppressants in the treatment of primary IgA nephropathy in children.

METHODS

English and Chinese electronic databases were searched to include the studies on the efficacy and safety of steroid combined with immunosuppressants versus steroid alone in the treatment of primary IgA nephropathy in children. Outcome measures included proteinuria remission rate, urinary protein quantification, incidence of adverse events, estimated glomerular filtration rate, and incidence of renal dysfunction. Review Manager 5.3 software was used for data analysis.

RESULTS

A total of 7 studies with 381 children were included. The children had moderate to severe proteinuria. The Meta analysis showed that compared with the steroid alone group, the steroid combined with immunosuppressants group achieved a significantly higher rate of proteinuria remission (RR=1.36, 95%CI: 1.19-1.55, P<0.001) and significantly lower urinary protein quantification (SMD=-0.82, 95%CI: -1.23 to -0.41, P<0.001). There was no significant difference in the incidence rate of adverse events between the two groups (RR=1.28, 95%CI: 0.92-1.77, P=0.14).

CONCLUSIONS

The current evidence shows that for children with primary IgA nephropathy who have moderate to severe proteinuria, steroid combined with immunosuppressants has a better effect than steroid alone and does not increase the incidence rate of adverse events.

Initial serum creatinine concentration affects clinical outcomes in patients with IgA nephropathy treated with mycophenolate mofetil combined with low-dose prednisone

Indicators for predicting the efficacy of mycophenolate mofetil (MMF) have so far remained elusive. The present study aimed to identify predictive indicators of the efficacy of MMF combined with low-dose prednisone in patients with IgA nephropathy. A total of 598 patients presenting with primary IgA nephropathy at our center were screened. Patients were followed up for 18 months, where the end-point was defined as complete clinical remission. Cox proportional hazards models were performed for analyzing the initial serum creatinine (SCr) concentration to predict incomplete clinical remission. In total, 7 of 71 patients (9.86%) were in complete clinical remission at the final visit. Logistic regression indicated that the hazard ratio (HR) for quartile 4 was significantly higher than the HR for quartile 1 (quartile 4 vs. quartile 1: HR, 2.51; 95% CI, 1.20-5.21; P=0.01). Additional adjustment for the confounding variables, including age, sex, systolic BP, diastolic BP, proteinuria, uric acid, serum triglyceride, hemoglobin, serum albumin, serum total cholesterol and The Oxford classification of the models, did not reduce the HRs for the association between the initial SCr concentration and risk of incomplete clinical remission (quartile 4 vs. quartile 1: HR, 7.27; 95% CI, 1.21-43.63; P=0.03). Each unit increase in the initial SCr concentration was associated with a 67 and 194% increase in the risk of incomplete clinical remission based on model 1 (95% CI, 1.02-2.73; P=0.04) and model 2 (95% CI, 1.01-8.60; P=0.048), respectively. In conclusion, in the present cohort of patients with IgA nephropathy treated with MMF plus low-dose prednisone, the initial SCr concentration was an independent risk factor for incomplete clinical remission.

Efficacy and safety of leflunomide in IgA nephropathy: a systematic review and meta-analysis

BACKGROUND

The optimal therapy for immunoglobulin A nephropathy (IgAN) remains uncertain. Leflunomide (LEF) is an immunosuppressive drug which may reduce deposition of glomerular autoantibodies and immune complexes. Several clinical trials were designed to evaluate the efficacy of LEF, but their results were controversial.

METHODS

Ovid Medline, Embase, the Cochrane Library, PubMed, and CNKI were systematically searched. Search terms included ("glomerulonephritis" OR "nephritis") AND ("immunoglobulin A" OR "IgA") AND "leflunomide". Studies in which patients were diagnosed with IgAN based on renal biopsy were included. Studies needed to report clinical outcomes via either short- or long-term clinical examination, remission rate, or complication rate.

RESULTS

Forty-four studies encompassing 1802 patients were included, of which 35 were randomized controlled trials. Results of 24 h post-treatment urine protein tests and serum creatinine tests were significantly lower in patients treat with LEF and corticosteroids (CS) or valsartan (ACEI) (CS + LEF or CS + ACEI) compared with patients treated with CS or ACEI alone (P < 0.05). More patients treated with CS + LEF (31.2%) achieved complete remission (CR) than patients treated with CS alone (22.2%) (RR = 0.71, 95% CI 0.59-0.85, P < 0.05). Although there was no significant difference in CR between patients treated with cyclophosphamide and CS (CS + CTX) and those treated with CS + LEF, the complication rate in the former group was higher (28.4%) than in the latter one (11.4%) (RR = 2.46, 95% CI 1.47-4.13, P < 0.005).

CONCLUSION

LEF appears to improve renal function while decreasing loss of urine protein. Combination regimens including LEF were better and safer compared with CS or ACEI alone or combinations including CTX.

Recent advances in risk prediction, therapeutics and pathogenesis of IgA nephropathy

Immunoglobulin A nephropathy (IgAN) is the world's commonest primary glomerular disease with variable clinical presentation and progression rates that are dependent on clinical-pathologic phenotype and duration of follow-up. Overall 4-40% of patients progress to end-stage kidney disease (ESKD) by 10 years. Treatment decisions remain a challenge due to these variations. The ultimate goal of management is to prevent progression to ESKD and of vital importance is the potential reversible early detection of active glomerular inflammation prior to scarring. IgAN is globally, is the most common biopsy proven glomerulonephritis and a leading cause of ESKD. The Oxford pathological classification was devised by a collaborative pathology and nephrology network to provide an evidence-based scoring system with reproducible independent pathology features of predictive value. Clinical variables that alter prognosis include male sex, increasing age, increased body weight, smoking, Pacific Asian ethnicity, hypertension, proteinuria, and complement deficiency. Excellent conservative therapy is the cornerstone of therapy with tight blood control, renin-angiotensin system inhibition, and statin therapy. The role of immunosuppressive therapy including corticosteroids in IgAN remains open with ongoing clinical trials of low dose oral corticosteroids and enteric coated budesonide. Complement activation contributes to the pathogenic process of IgAN with evidence from genetic, serological, histological and in-vitro studies. This knowledge has translated to clinical trials of investigational agents directly targeting the alternative pathway.

Is immunoglobulin A nephropathy different in different ethnic populations?

Immunoglobulin A nephropathy (IgAN) is one of the commonest global patterns of primary glomerulonephritis and remains a leading cause of chronic kidney disease and end-stage renal disease. The sole diagnostic criterion of IgAN remains the presence of dominant mesangial immunoglobulin A deposits on kidney biopsy. Beyond this defining feature, there is significant heterogeneity in the epidemiology, clinical presentation, renal progression and long-term outcomes of IgAN in different ethnic populations. Mirroring this heterogeneity in clinical phenotypes, there is also marked ethnic variation in the extent of histopathological lesions observed on kidney biopsy, which may partly explain the well-documented differences in response to immunomodulatory agents reported in different regions of the world. In parallel, disparities have been identified in genetic association studies and key pathogenic pathways in different ethnic populations. Understanding the basis for these differences in IgAN has important implications for both clinical care and future research. In this review, we will examine the impact of ethnicity on the epidemiology, clinical presentation and outcomes, pathogenesis and genetic associations in IgAN.

Indoleamine 2,3-Dioxygenase (IDO) Regulates Th17/Treg Immunity in Experimental IgA Nephropathy

IgA nephropathy (IgAN) is the most common glomerulonephritis worldwide. Current studies have shown that the Th17/Treg immune balance may be involved in the occurrence of IgAN, but the exact mechanism is still unclear. Indoleamine 2,3-dioxygenase (IDO) is an enzyme that catalyses degradation of tryptophan (Trp) through the kynurenine (Kyn) pathway; it can control inflammation and immune response by inducing Trp starvation. IDO may be a key molecule in regulating the Th17/Treg immune balance. However, it is not clear whether IDO is involved in the IgAN disease occurrence by regulating the Th17/Treg immune balance. In this study, an IgAN mouse model was established. The mice were intraperitoneally inoculated with IDO inhibitor 1-MT or agonist ISS-ODN to observe whether the IDO signalling pathway participates in the occurrence and development of IgAN by regulating the Th17/Treg immune balance. The results showed that IDO inhibitor 1-MT significantly increased renal injury and glomerular IgA accumulation and up-regulated Th17/Treg and Th17-related cytokine expression in IgAN mice, while ISS-ODN significantly decreased renal injury and glomerular IgA accumulation, down-regulated Th17/Treg expression and inhibited Th17-related cytokine expression in IgAN mice. In conclusion, IDO was involved in the occurrence and progress of IgAN by regulating the Th17/ Treg balance.

Treatment of IgA nephropathy: Recent advances and prospects

IgA nephropathy, identified 50 years ago in France, is the most frequent glomerular disease worldwide. The course is variable, but in most of the cases there is a relentless decline in renal function, reaching end-stage renal failure in 10-60% of the cases after 10 years and in 40% after 20 years. These data justify the interest for finding a suitable therapeutic approach particularly in progressive cases. A supportive care, including renin-angiotensin system inhibitors is the priority in cases with slowly declining renal function, particularly when developing proteinuria. The recent supportive versus immunosuppressive therapy for the treatment of progressive IgA nephropathy (STOP-IgAN) randomized and controlled trial has further stressed the benefit of a strict supportive care including also life-style changes, protein and salt restriction. However, there is clear evidence from observational studies (including the European Validation Study of the Oxford Classification of IgA nephropathy [VALIGA]) and a new randomized and controlled trial (Therapeutic Evaluation of Steroids in IgA Nephropathy Global [TESTING]) of additional benefits of corticosteroid treatment in patients with proteinuric IgA nephropathy. However, the present treatment schedules carry severe side effects, mostly infectious complications, which indicate the need for less toxic interventions. The recent focus on the role of gut-kidney axis in IgA nephropathy has led to the search of corticosteroid formulations targeting the intestinal mucosal immune system (gut-associated lymphoid tissue). The NEFIGAN trial obtained interesting results in terms of reduction of proteinuria and stabilization of renal function using a budesonide formulation allowing a selective drug delivery at intestinal gut-associated lymphoid tissue sites. The adverse events, particularly infections, were found to be not clinically relevant. The possibility of a personalized approach to the treatment according to the renal biopsy lesions (Oxford MEST score) is supported by several uncontrolled studies and deserves great attention in the next future. New treatments options for IgA nephropathy include drugs targeting BAFF, a B-cell factor crucial for IgA synthesis or targeting the complement system, and also the possibility of acting directly on the deposited IgA by selective protease digestion.

The Emerging Role of Pathogenesis of IgA Nephropathy

IgA nephropathy is an autoimmune disease induced by fthe ormation of galactose-deficient IgA1 and anti-glycans autoantibody. A multi-hit hypothesis was promoted to explain full expression of IgA nephropathy. The deposition of immune complex resulted in activation of the complement, increasing oxidative stress, promoting inflammatory cascade, and inducing cell apoptosis via mesangio-podocytic-tubular crosstalk. The interlinked signaling pathways of immune-complex-mediated inflammation can offer a novel target for therapeutic approaches. Treatments of IgA nephropathy are also summarized in our review article. In this article, we provide an overview of the recent basic and clinical studies in cell molecular regulation of IgAN for further treatment interventions.

Efficacy and safety of mycophenolate mofetil for IgA nephropathy: An updated meta-analysis of randomized controlled trials

The efficacy and safety of mycophenolate mofetil (MMF) for immunoglobulin A nephropathy (IgAN) remains debatable. Therefore, the present meta-analysis was conducted with randomized controlled trials (RCTs). PubMed/MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials were analyzed to identify eligible trials. The pooled risk ratio (RR) with 95% confidence interval (CI) was estimated for all the dichotomous outcome measures. A total of eight RCTs with nine publications (n=510 patients) were included. No significant difference was noted between therapeutic regimens with and without MMF for renal remission and end stage renal disease (ESRD) of patients with IgAN (seven trials; RR, 1.250; 95% CI, 0.993–1.574; P=0.057; and four trials; RR, 0.728; 95% CI, 0.164–3.236; P=0.676). To further define the effects of MMF for renal remission, subgroup analysis was performed, demonstrating that MMF was significantly more effective compared with the placebo (three trials; RR, 2.152; 95% CI, 1.198–3.867; P=0.010), although the immunosuppressive regimens with MMF had no significantly different effects compared with those without MMF (four trials; RR, 1.140; 95% CI, 0.955–1.361; P=0.146), indicating that MMF was superior to placebo and had a similar efficacy to other immunosuppressants for renal remission. In addition, subgroup analysis for ESRD revealed no significant differences between MMF and placebo and between the immunosuppressive regimens with and without MMF (three trials; RR, 0.957; 95% CI, 0.160–5.726; P=0.962; and one trial; RR, 0.205; 95% CI, 0.010–4.200; P=0.303). Furthermore, there were no significant differences between the therapeutic regimens with and without MMF in terms of the risk of adverse events. The present meta-analysis demonstrated that MMF was more effective compared with the placebo, may have similar efficacy to other immunosuppressants in terms of inducing renal remission of IgAN and may not increase the risk of adverse events. The long-term effects of MMF on the prognosis of patients with IgAN require verification in further studies.

Is mycophenolate mofetil combined with low-dose prednisone a treatment option for advanced IgA nephropathy? A 10-year follow-up case and brief literature review

IgA nephropathy (IgAN) is now widely recognized as the most common primary glomerulonephritis worldwide, especially in China. The immunosuppressive treatment option for IgAN is still controversial. Previously, we proved that mycophenolate mofetil (MMF; Shanghai Roche, China) combined with low-dose prednisone was an effective and safe option for biopsy-proven mild to moderate IgAN patients in a short term of follow-up. This article we first reported the safety and efficacy of this regimen in a 42-year-old male biopsy-proven advanced 10-year follow-up IgAN case (Lee’s Class V; the patient was biopsied 10 years ago, so the Oxford Mesangial hypercellularity Endocapillary hypercellularity Segmental glomerulosclerosis Tubular atrophy/interstitial fibrosis (MEST) classification was not used). The mycophenolate and prednisone were only given for a limited time. The other main medications included calcium channel blockers and antiplatelet agents. Clinical and laboratory indexes were aperiodic assessed during the 10-year follow-up. The serum creatinine decreased from 356 to around 210 μmol/L and urine excretion protein reduced from 3.4 g/d to about 0.5 g/d after 6 months of the initiation of this regimen, respectively. These perfect treatment effects could maintain well during the whole follow-up period. No obvious complications were observed.