Optimal proteinuria target for renoprotection in patients with IgA nephropathy

Primary IgA Nephropathy: New Insights and Emerging Therapies

Primary IgA nephropathy (IgAN) is a common glomerular disorder defined by predominant mesangial IgA deposition. Once thought to follow a progressive course in 10-20% of those diagnosed, emerging evidence now suggests most will progress to kidney failure over their lifetimes. Although the lack of safe and effective treatments to impede disease progression continues to present a challenge, the landscape of IgAN has dramatically evolved over the last 2 years. Driven by fundamental changes to accepted end points for IgAN clinical trials as well as fascinating new insights into the pathophysiology of IgAN, a swathe of novel and repurposed therapies are currently being evaluated. Already, two novel drugs, targeted-release formulation budesonide and sparsentan, have received conditional approvals for the treatment of IgAN, with sodium glucose co-transporter 2 inhibitors establishing themselves as further options. Soon to join this ensemble are likely to be treatments that modulate the complement system and B-cell activity; several are currently undergoing clinical trials in IgAN with promising interim results. In this review, we provide an overview of evolving epidemiological insights, disease mechanisms, emerging therapies, and contemporary challenges surrounding the management of IgAN.

External validation of the International Prediction Tool in Korean patients with immunoglobulin A nephropathy

Background

The International IgA Nephropathy Prediction Tool (International IgA Nephropathy Prediction Tool) has been recently developed to estimate the progression risk of immunoglobulin A nephropathy (IgAN). This study aimed to evaluate the clinical performance of this prediction tool in a large IgAN cohort in Korea.

Methods

The study cohort was comprised of 2,064 patients with biopsy-proven IgAN from four medical centers between March 2012 and September 2021. We calculated the predicted risk for each patient. The primary outcome was occurrence of a 50% decline in estimated glomerular filtration rate (eGFR) from the time of biopsy or end-stage kidney disease. The model performance was evaluated for discrimination, calibration, and reclassification. We also constructed and tested an additional model with a new coefficient for the Korean race.

Results

During a median follow-up period of 3.8 years (interquartile range, 1.8–6.6 years), 363 patients developed the primary outcome. The two prediction models exhibited good discrimination power, with a C-statistic of 0.81. The two models generally underestimated the risk of the primary outcome, with lesser underestimation for the model with race. The model with race showed better performance in reclassification compared to the model without race (net reclassification index, 0.13). The updated model with the Korean coefficient showed good agreement between predicted risk and observed outcome.

Conclusion

In Korean IgAN patients, International IgA Nephropathy Prediction Tool had good discrimination power but underestimated the risk of progression. The updated model with the Korean coefficient showed acceptable calibration and warrants external validation.

Effects of Hydroxychloroquine on Proteinuria in IgA Nephropathy: A Systematic Review and Meta-Analysis

Introduction

The present meta-analysis was to explore the efficacy of hydroxychloroquine (HCQ) in IgA nephropathy patients in terms of proteinuria.

Method

We systematically searched PubMed and Embase for studies that compared HCQ and other treatments to reduce proteinuria in patients with IgA nephropathy up to June 2021. Mean ± SD of percentage change and level of proteinuria was calculated.

Results

A total of 5 studies with 587 participants were included. IgA nephropathy patients who received HCQ were at a lower level of mean proteinuria at 6 months. However, there was no statistical difference between HCQ and control group considering percentage reduction in proteinuria. The long-term therapeutic effect of HCQ might be inferior to HCQ and renin-angiotensin-aldosterone system inhibition.

Conclusion

HCQ might play a role in the reduction of proteinuria in IgA nephropathy patients. The addition of HCQ to other immunosuppressive agents should be clarified further.

Assessing Patient Preferences in Rare Diseases: Direct Preference Elicitation in the Rare Chronic Kidney Disease, Immunoglobulin A Nephropathy

Background

Patient preference information is increasingly being used to inform decision making; however, further work is required to support the collection of preference information in rare diseases. This study illustrates the use of direct preference elicitation methods to collect preference data from small samples in the context of early decision making to inform the development of a product for the treatment of immunoglobulin A nephropathy.

Method

An interview-based swing weighting approach was used to elicit preferences from 40 patients in the US and China. Attributes were identified through a background review, expert engagement and patient focus groups. Participants completed a series of tasks that involved ranking, rating and scoring improvements in the attributes to obtain attribute swing weights and partial value functions. The preference results were then incorporated into a benefit-risk assessment simulation tool.

Results

Participants placed the greatest value on avoiding end-stage renal/kidney disease. Similar weight was given to short-term quality-of-life improvements and avoiding infections. Treatment burden (number of vaccinations) received the least weight. Heterogeneity in preferences was also observed. Consistency tests did not identify statistically significant variation in preferences, and qualitative data suggested that the elicitation exercise was sensitive to participants’ interpretation of attributes and that participants were able to express their preferences.

Conclusion

Direct preference elicitation methods can be used to collect preference data from small samples. Further work should continue to test the validity of the estimate generated by such methods.

Supplementary Information

The online version contains supplementary material available at 10.1007/s40271-021-00521-3.

Reduction in proteinuria after immunosuppressive therapy and long-term kidney outcomes in patients with immunoglobulin A nephropathy

BACKGROUND/AIMS

Despite controversy regarding the benefits of immunosuppressive therapy in immunoglobulin A nephropathy (IgAN), clinical outcomes may vary depending on the patient's responsiveness to this therapy. This study evaluated long-term kidney outcomes according to the extent of proteinuria reduction after immunosuppression in IgAN patients.

METHODS

Among 927 patients with biopsy-proven IgAN, 127 patients underwent immunosuppression. Time-averaged urine protein-creatinine ratio before and within 1 year after start of immunosuppression were calculated, and responsiveness to immunosuppression was assessed as the reduction of proteinuria between the two periods. Patients were classified into tertiles according to the extent of proteinuria reduction. We compared the slopes of estimated glomerular filtration rate (eGFR) decline using a linear mixed model, and estimated hazard ratios (HRs) for disease progression (defined as development of a ≥ 30% decline in eGFR or end-stage renal disease) using a Cox proportional hazard model.

RESULTS

Median extent of proteinuria reduction was -2.1, -0.9, and -0.2 g/gCr in the first, second, and third tertiles, respectively. There were concomitant changes in the slopes of annual eGFR decline: -2.03, -2.44, and -4.62 mL/min/1.73 m2 among the first, second, and third tertiles, respectively. In multivariable Cox analysis, the HRs (95% confidence intervals) for disease progression were 0.30 (0.12 to 0.74) in the first tertile and 0.70 (0.34 to 1.45) in the second tertile compared with the thirdtertile.

CONCLUSION

This study showed that greater proteinuria reduction after immunosuppression was associated with a lower risk of disease progression in patients with IgAN, suggesting that responsiveness to immunosuppression may be an important determinant of kidney outcomes.

The Non-Coding RNA Landscape in IgA Nephropathy-Where Are We in 2021?

IgA nephropathy (IgAN) is the most commonly diagnosed primary glomerulonephritis worldwide. It is a slow progressing disease with approximately 30% of cases reaching end-stage kidney disease within 20 years of diagnosis. It is currently only diagnosed by an invasive biopsy and treatment options are limited. However, the current surge in interest in RNA interference is opening up new horizons for the use of this new technology in the field of IgAN management. A greater understanding of the fundamentals of RNA interference offers exciting possibilities both for biomarker discovery and, more importantly, for novel therapeutic approaches to target key pathogenic pathways in IgAN. This review aims to summarise the RNA interference literature in the context of microRNAs and their association with the multifaceted aspects of IgA nephropathy.

Long term outcome of immunoglobulin A (IgA) nephropathy: A single center experience

INTRODUCTION

IgA nephropathy (IgAN) has a heterogeneous presentation and the progression to end stage renal disease (ESRD) is often influenced by demographics, ethnicity, as well as choice of treatment regimen. In this study, we investigated the long term survival of IgAN patients in our center and the factors affecting it.

METHODS

This study included all biopsy-proven IgAN patients with ≥ 1year follow-up. Patients with diabetes mellitus at diagnosis and secondary IgAN were excluded. Medical records were reviewed for demographics, clinical presentation, blood pressure, 24-hour urine protein, serum creatinine, renal biopsy and treatment received. The primary outcome was defined as combined event of 50% estimated glomerular filtration rate (eGFR) reduction or ESRD.

RESULTS

We included 130 (74 females; 56 males) patients of mean age 38.0 ± 14.0 years and median eGFR of 75.2 (interquartile range (IQR) 49.3-101.4) ml/min/1.73m2. Eighty-four (64.6%) were hypertensive at presentation, 35 (26.9%) had nephrotic syndrome and 57 (43.8%) had nephrotic range proteinuria (NRP). Median follow-up duration was 7.5 (IQR 4.0-13.0) years. It was noted that 18 (13.8%) developed ESRD and 34 (26.2%) reached the primary outcome. Annual eGFR decline was -2.1 (IQR -5.3 to -0.1) ml/min/1.73m2/year, with median survival of 20 years. Survival rates from the combined event (50% decrease in eGFR or ESRD) at 10, 20 and 30 years were 80%, 53% and 25%, while survival from ESRD were 87%, 73% and 65%, respectively. In the univariate analysis, time-average proteinuria (hazard ratio (HR) = 2.41, 95% CI 1.77-3.30), eGFR <45ml/min/1.73m2 at biopsy (HR = 2.35, 95% CI 1.03-5.32), hypertension (HR = 2.81, 95% CI 1.16-6.80), mean arterial pressure (HR = 1.02, 95% CI 1.01-1.04), tubular atrophy/interstitial fibrosis score (HR = 3.77, 95% CI 1.84-7.73), and cellular/fibrocellular crescent score (HR = 2.44, 95% CI 1.19-5.00) were found to be significant. Whereas only time-average proteinuria (TA-proteinuria) remained as a significant predictor in the multivariate analysis (HR = 2.23, 95% CI 1.57-3.16).

CONCLUSION

In our cohort, TA-proteinuria was the most important predictor in the progression of IgAN, irrespective of degree of proteinuria at presentation.

Systolic blood pressure and chronic kidney disease progression in patients with primary glomerular disease

INTRODUCTION

Many current guidelines on optimal target blood pressure (BP) for chronic kidney disease (CKD) patients are largely based on studies in diabetic and hypertensive patients. However, there have been few studies in patients with glomerular diseases.

METHODS

We retrospectively studied the longitudinal association between BP and CKD progression in 1,066 biopsy-proven patients diagnosed with primary glomerular diseases, including IgA nephropathy, membranous nephropathy (MN), and focal segmental glomerulosclerosis (FSGS), between 2005 and 2017. The main predictor was time-updated systolic blood pressure (SBP) at every clinic visit. The primary outcome was a composite one including ≥ 50% decrease in estimated glomerular filtration rate (eGFR) from the baseline, and end-stage kidney disease (ESKD).

RESULTS

During 5009 person-years of follow-up, the primary outcome occurred in 157 (14.7%) patients. In time-varying Cox model, the adjusted hazard ratios (HRs) (95% confidence interval (CI)) for the primary outcome were 1.48 (0.96-2.29), 2.07 (1.22-3.52), and 2.53 (1.13-5.65) for SBP of 120-129, 130-139, and ≥ 140 mmHg, respectively, compared with SBP < 120 mmHg. This association was particularly evident in patients with elevated proteinuria. However, there was no association between baseline SBP and adverse kidney outcomes. Finally, prediction models failed to show the improvement of predictive performance of SBP compared with that of remission status. Moreover, patients with remission and less controlled SBP had better kidney outcomes than those with non-remission and well-controlled SBP.

CONCLUSION

Among patients with glomerular disease, higher time-updated SBP was significantly associated with higher risk of CKD progression. However, the clinical significance of blood pressure was less powerful than remission status.

Monitoring Immune Responses in IgA Nephropathy: Biomarkers to Guide Management

IgA nephropathy (IgAN) is the commonest biopsy-reported primary glomerulonephritis worldwide. It has an incidence which peaks among young adults, and 30 to 40% of patients' progress to end stage kidney disease within twenty years of diagnosis. Ten-year kidney survival rates have been reported to be as low as 35% in some parts of the world. The successful management of IgAN is limited by an incomplete understanding of the pathophysiology of IgAN and a poor understanding of how pathophysiology may vary both from patient to patient and between patient groups, particularly across races. This is compounded by a lack of rigorously designed and delivered clinical trials in IgAN. This is slowly changing, with a number of Phase 2 and 3 clinical trials of novel therapies targeting a number of different putative pathogenic pathways in IgAN due to report in the next 5 years. From our current, albeit limited, understanding of the pathophysiology of IgAN it is unlikely a single therapy will be effective in all patients with IgAN. The successful management of IgAN in the future is, therefore, likely to be reliant on targeted therapies, carefully selected based on an individualized understanding of a patient's risk of progression and underlying pathophysiology. The potential role of biomarkers to facilitate personalization of prognostication and treatment of IgAN is immense. Here we review the progress made over the past decade in identifying and validating new biomarkers, with a particular focus on those that reflect immunological responses in IgAN.

Corticosteroids or immunosuppressants were not superior to supportive care in IgA nephropathy patients with mild proteinuria

BACKGROUND

We aimed to evaluate the effect of immunosuppressant therapy for immunoglobulin A nephropathy (IgAN) patients with mild proteinuria (<1 g/d).

METHODS

We recruited patients with biopsy-proven IgAN from 4 study centers. Patients were followed for more than 1 year or up to the study end point. Clinical indexes, renal pathological data, and treatment information were collected during the follow-up period. IgAN patients with mild proteinuria (<1 g/d at biopsy) were included. Patients were divided into a supportive care group (SC) and an immunosuppressant group (IT). Patients in the SC group received the optimal dose of renin angiotensin system inhibitors (RASi). Patients in the IT group received corticosteroids or immunosuppressant therapy plus RASi. Responses to therapy included complete remission (CR), partial remission (PR), no response (NR), and end stage renal disease (ESRD). A 50% decline in estimated glomerular filtration rate (eGFR) and/or ESRD was the primary end point of this study.

RESULTS

295 patients (36.3% male and 63.7% female) were included in this study and were followed for 49.46 ± 24.35 months. We found a significant difference in estimated glomerular filtration rate, urine protein, mesangial hypercellularity, segmental glomerulosclerosis, cellular or fibrocellular crescents, and glomerulosclerosis between the 2 treatment groups at baseline. At the final follow-up, 224 patients (75.9%) achieved CR, 7 patients (2.4%) achieved PR, 55 patients (18.6%) had NR, and 9 patients (3.1%) reached ESRD. However, no significant differences were observed between the SC and IT groups with respect to CR (76.4% vs 73.5%, P = .659), PR (2.0% vs 4.1%, P = .329), NR (18.3% vs 20.4%, P = .728), and ESRD (3.3% vs 2.0%, P = 1.000). Kidney survival rates were also comparable between the SC and IT groups (93.7% vs 94.1%, P = .808). We observed similar results after subgroup analysis according to chronic kidney disease stages or pathological manifestations. A multivariate model showed that segmental sclerosis (HR 9.55, 95% CI 1.04-88.16, P = .047) and glomerulosclerosis (HR 21.09, 95% CI 1.39-320.53, P = .028) were independent predictors of poor renal survival.

CONCLUSIONS

Corticosteroids or immunosuppressants were not superior to supportive care in IgA nephropathy patients with mild proteinuria.

Predictive value of mesangial C3 and C4d deposition in IgA nephropathy

We aimed to determine the relative contribution of each complement (C3 and C4d) deposition to the progression of IgA nephropathy (IgAN). We enrolled a total of 380 patients with biopsy-confirmed IgAN. Mesangial deposition of C3(<2+ vs. ≥2+) and C4d(positive vs. negative) was evaluated by immunofluorescence staining and immunohistochemistry, respectively. Study endpoint was the composite of a 30% decline in eGFR or ESRD. The risk of reaching the primary outcome was significantly higher in patients having C3 ≥ 2+ and C4d(+) than in corresponding counterparts. Adding C3 deposition to clinical data acquired at kidney biopsy modestly increased the area under the receiver-operating characteristic curve, net reclassification improvement, and integrated discrimination improvement (IDI); adding C4d increased IDI only. In conclusion, mesangial C3 and C4d deposition was an independent risk factor for progression of IgAN. C3 showed better predictability than C4d, suggesting that lectin pathway alone has limited clinical prognostic value.

Inker L, Floege J, Perkovic V, Boyer-Suavet S, W. Major R, I. Schimpf J, Barratt J, Cattran DC, S. Gillespie B, Kausz A, W. Mercer A, Reich HN, H. Rovin B, West M, Nachman PH. Proteinuria Reduction as a Surrogate End Point in Trials of IgA Nephropathy

IgA nephropathy (IgAN) is an important cause of ESKD for which there are no approved therapies. A challenge for evaluating treatments for IgAN is the usual long time course for progression to ESKD. The aim of this Kidney Health Initiative project was to identify surrogate end points that could serve as reliable predictors of a treatment's effect on long-term kidney outcomes in IgAN and be used as a basis for approval. Proteinuria was identified as the most widely recognized and well studied risk factor for progression to ESKD in IgAN. The workgroup performed a critical review of the data on proteinuria reduction as a surrogate end point for a treatment's effect on progression to ESKD in IgAN. Epidemiologic data indicate a strong and consistent relationship between the level and duration of proteinuria and loss of kidney function. Trial-level analyses of data from 13 controlled trials also show an association between treatment effects on percent reduction of proteinuria and treatment effects on a composite of time to doubling of serum creatinine, ESKD, or death. We conclude that data support the use of proteinuria reduction as a reasonably likely surrogate end point for a treatment's effect on progression to ESKD in IgAN. In the United States, reasonably likely surrogate end points can be used as a basis for accelerated approval of therapies intended to treat serious or life-threatening conditions, such as IgAN. The clinical benefit of products approved under this program would need to be verified in a postmarketing confirmatory trial.

Seasonal proteinuria changes in IgA nephropathy patients after proteinuria remission

Background

Proteinuria is a powerful prognostic factor for end-stage renal disease in IgA nephropathy (IgAN) patients. However, it is not known whether proteinuria exacerbations are related to seasonal changes.

Methods

We retrospectively enrolled consecutive patients diagnosed with IgAN by kidney biopsy at our hospital between 2002 and 2014. Proteinuria remission was defined as urinary protein <0.3 g/gCr in two consecutive outpatient urinalyses and exacerbation as urinary protein ≥0.75 g/gCr. Four seasons were defined: spring (March–May), summer (June–August), autumn (September–November), and winter (December–February). We performed a multivariate analysis to identify factors associated with the second remission following a proteinuria exacerbation.

Results

We analyzed 116 patients. Proteinuria remission and exacerbation occurred in 77, and 43 patients, respectively. The incidence of proteinuria exacerbation was significantly higher in autumn and winter than in spring and summer (p = 0.040). The cumulative second remission rate was significantly higher in patients with autumn and winter proteinuria exacerbation than in patients with spring and summer exacerbations (p = 0.0091). In multivariate analyses, exacerbation onset in autumn and winter (hazard ratio [HR], 3.51; 95% confidence interval [CI], 1.41–8.74) and intensive therapy (HR, 2.26; 95% CI, 1.05–4.88) were significantly associated with a second proteinuria remission.

Conclusion

In IgAN patients in proteinuria remission, proteinuria exacerbation frequently occurred in autumn and winter. Exacerbations occurring in autumn and winter tended to remit early.

Determination of the optimal target level of proteinuria in the management of patients with glomerular diseases by using different definitions of proteinuria

Proteinuria is a major determinant of adverse renal outcome, and its reduction slows renal progression in glomerular diseases. However, the optimal target of proteinuria in glomerular diseases is unclear, and discrepancies in the definition of proteinuria produce ambiguous findings. Here we investigated the optimal target of proteinuria by using different definitions of proteinuria. We analyzed 574 IgA nephropathy (IgAN), 175 membranous nephropathy (MGN), and 177 focal segmental glomerulosclerosis (FSGS) cases from 3 Korean kidney centers. We evaluated the impact of proteinuria on renal outcome with 2 definitions: time-average proteinuria (TAP) and time-varying proteinuria (TVP). The endpoint was renal progression, defined as a 50% decline in glomerular filtration rate or end-stage renal disease. During a median follow-up of 57.3 months, the primary outcome occurred in 54 patients with IgAN, 26 with MGN, and 30 with FSGS. Multivariate Cox regression using TAP indicated that there was a linear association between proteinuria and risk of renal progression in IgAN. However, moderate proteinuria was not associated with an increased risk of renal progression in MGN and FSGS. In contrast, the analysis by TVP showed that the risk significantly increased in proportion to proteinuria during follow-up in all 3 diseases. Our findings suggest that TVP-based model can delineate association between proteinuria and risk of renal progression better than TAP-based model, considering that TVP reflects the dynamic change of proteinuria over time. Thus, proteinuria reduction to the lowest possible level is required to improve renal outcomes in patients with glomerular diseases.

Targeted-release budesonide versus placebo in patients with IgA nephropathy (NEFIGAN): a double-blind, randomised, placebo-controlled phase 2b trial

BACKGROUND

IgA nephropathy is thought to be associated with mucosal immune system dysfunction, which manifests as renal IgA deposition that leads to impairment and end-stage renal disease in 20-40% of patients within 10-20 years. In this trial (NEFIGAN) we aimed to assess safety and efficacy of a novel targeted-release formulation of budesonide (TRF-budesonide), designed to deliver the drug to the distal ileum in patients with IgA nephropathy.

METHODS

We did a randomised, double-blind, placebo-controlled phase 2b trial, comprised of 6-month run-in, 9-month treatment, and 3-month follow-up phases at 62 nephrology clinics across ten European countries. We recruited patients aged at least 18 years with biopsy-confirmed primary IgA nephropathy and persistent proteinuria despite optimised renin-angiotensin system (RAS) blockade. We randomly allocated patients with a computer algorithm, with a fixed block size of three, in a 1:1:1 ratio to 16 mg/day TRF-budesonide, 8 mg/day TRF-budesonide, or placebo, stratified by baseline urine protein creatinine ratio (UPCR). Patients self-administered masked capsules, once daily, 1 h before breakfast during the treatment phase. All patients continued optimised RAS blockade treatment throughout the trial. Our primary outcome was mean change from baseline in UPCR for the 9-month treatment phase, which was assessed in the full analysis set, defined as all randomised patients who took at least one dose of trial medication and had at least one post-dose efficacy measurement. Safety was assessed in all patients who received the intervention. This trial is registered with ClinicalTrials.gov, number NCT01738035.

FINDINGS

Between Dec 11, 2012, and June 25, 2015, 150 randomised patients were treated (safety set) and 149 patients were eligible for the full analysis set. Overall, at 9 months TRF-budesonide (16 mg/day plus 8 mg/day) was associated with a 24·4% (SEM 7·7%) decrease from baseline in mean UPCR (change in UPCR vs placebo 0·74; 95% CI 0·59-0·94; p=0·0066). At 9 months, mean UPCR had decreased by 27·3% in 48 patients who received 16 mg/day (0·71; 0·53-0·94; p=0·0092) and 21·5% in the 51 patients who received 8 mg/day (0·76; 0·58-1·01; p=0·0290); 50 patients who received placebo had an increase in mean UPCR of 2·7%. The effect was sustained throughout followup. Incidence of adverse events was similar in all groups (43 [88%] of 49 in the TRF-budesonide 16 mg/day group, 48 [94%] of 51 in the TRF-budesonide 8 mg/day, and 42 [84%] of 50 controls). Two of 13 serious adverse events were possibly associated with TRF-budesonide-deep vein thrombosis (16 mg/day) and unexplained deterioration in renal function in follow-up (patients were tapered from 16 mg/day to 8 mg/day over 2 weeks and follow-up was assessed 4 weeks later).

INTERPRETATION

TRF-budesonide 16 mg/day, added to optimised RAS blockade, reduced proteinuria in patients with IgA nephropathy. This effect is indicative of a reduced risk of future progression to end-stage renal disease. TRF-budesonide could become the first specific treatment for IgA nephropathy targeting intestinal mucosal immunity upstream of disease manifestation.

FUNDING

Pharmalink AB.

Clinical usefulness of the Oxford classification in determining immunosuppressive treatment in IgA nephropathy

BACKGROUND

The Oxford classification has been widely used in IgA nephropathy. However, its clinical usefulness of determining immunosuppression is unknown.

AIM

Whether the Oxford classification could predict the development of proteinuria ≥1 g/g Cr and worsening kidney function, as well as the clinical efficacy of corticosteroid treatment according to each histologic variable of the Oxford-MEST.

METHODS

We included 377 patients with early-stage IgA nephropathy. The study endpoints were the development of a heavy proteinuria and a decline renal function.

RESULTS

The results showed that among the Oxford-MEST lesions, only M1 predicted the risk of the development of proteinuria ≥1.0 g/g Cr compared to other lesions in a time-varying Cox model adjusted for multiple confounding factors. In addition, the risk of reaching a 30% decline in eGFR was significantly higher in patients with M1 than in those with M0. Furthermore, patients with M1 had a greater decline of eGFR than patients with M0. However, steroid treatment in M1 lesion was not associated with improving clinical outcomes in the unmatched and propensity score matched cohort.

CONCLUSIONS

This finding may provide a rationale for using the Oxford classification as a guidance to initiate immunosuppression in the early stages of IgA nephropathy. KEY MESSAGES M1 has independently predictive role among the Oxford lesions in IgA nephropathy. Oxford classification should be defined during pathologic approach. Decision of starting immunosuppression according to the Oxford lesions.

Corticosteroids in IgA Nephropathy: Lessons from Recent Studies

IgA nephropathy (IgAN) is a common chronic glomerular disease that, in most patients, slowly progresses to ESRD. The immune and autoimmune responses that characterize IgAN indicate a potential benefit for corticosteroids. The 2012 Kidney Disease Improving Global Outcome (KDIGO) guidelines suggest giving corticosteroids to patients with rather preserved renal function (GFR>50 ml/min per 1.73 m²) and persistent proteinuria >1 g/d, despite 3-6 months of optimized supportive care with renin-angiotensin system blockers. However, the evidence supporting this guideline was considered of low quality. More recent results from large cohort studies and randomized, controlled trials have provided conflicting messages about the benefits of corticosteroid treatment over supportive care alone, mostly involving optimized renin-angiotensin system blockade, which might generate further uncertainty in the therapeutic choice. Overall, these results indicate that corticosteroids are a powerful tool for treating patients with IgAN; however, treatment success is not universal and mostly occurs in patients who are highly proteinuric with early CKD. In patients with advanced CKD, the side effects of corticosteroids increase, and the renal protection decreases. This brief review aimed at integrating the findings of these recently published reports to provide balanced advice for clinicians as well as suggestions for future trials.

Glomerular epithelial CD44 expression and segmental sclerosis in IgA nephropathy

BACKGROUND

CD44 is a marker of activated parietal epithelial cells (PECs), and is expressed in glomerular visceral epithelial cells (VECs) during development of segmental sclerosis. We explored the significance of glomerular epithelial CD44 expression in relation to segmental sclerosis in patients with mild IgA nephropathy (IgAN).

METHODS

A total of 126 cases of IgAN were divided into three groups based on glomerular morphology: normal (group A, n = 30), mild mesangial proliferation without segmental sclerosis or synechia (SS) (group B, n = 31), or mild mesangial proliferation with SS (group C, n = 65). The number of CD44-expressing PECs and VECs was counted in each glomerulus and expressed as the mean number per case.

RESULTS

CD44 staining was positive in VECs in 59.5 %, in PECs in 79.4 % and in both cell types in 56.3 % of cases. The number of CD44⁺ PECs or VECs was significantly higher in group C than in groups A or B. Cases with >1 CD44⁺ cell (PECs and VECs) per glomerulus were associated with increased urine protein/creatinine ratio (UPCr) at last follow-up. The presence of >1 CD44⁺ VEC/glomerulus was associated with increased UPCr and serum creatinine levels, and decreased estimated glomerular filtration rate (eGFR) even in the absence of SS at the time of biopsy.

CONCLUSION

CD44 was expressed in PECs and VECs in association with SS in IgAN. Increased CD44 expression in VECs is a sign of active glomerular injury and dysfunction in these patients.

Intensive Supportive Care plus Immunosuppression in IgA Nephropathy

BACKGROUND

The outcomes of immunosuppressive therapy, when added to supportive care, in patients with IgA nephropathy are uncertain.

METHODS

We conducted a multicenter, open-label, randomized, controlled trial with a two-group, parallel, group-sequential design. During a 6-month run-in phase, supportive care (in particular, blockade of the renin-angiotensin system) was adjusted on the basis of proteinuria. Patients who had persistent proteinuria with urinary protein excretion of at least 0.75 g per day were randomly assigned to receive supportive care alone (supportive-care group) or supportive care plus immunosuppressive therapy (immunosuppression group) for 3 years. The primary end points in hierarchical order were full clinical remission at the end of the trial (protein-to-creatinine ratio <0.2 [with both protein and creatinine measured in grams] and a decrease in the estimated glomerular filtration rate [eGFR] of <5 ml per minute per 1.73 m(2) of body-surface area from baseline) and a decrease in the eGFR of at least 15 ml per minute per 1.73 m(2) at the end of the trial. The primary end points were analyzed with the use of logistic-regression models.

RESULTS

The run-in phase was completed by 309 of 337 patients. The proteinuria level decreased to less than 0.75 g of urinary protein excretion per day in 94 patients. Of the remaining 162 patients who consented to undergo randomization, 80 were assigned to the supportive-care group, and 82 to the immunosuppression group. After 3 years, 4 patients (5%) in the supportive-care group, as compared with 14 (17%) in the immunosuppression group, had a full clinical remission (P=0.01). A total of 22 patients (28%) in the supportive-care group and 21 (26%) in the immunosuppression group had a decrease in the eGFR of at least 15 ml per minute per 1.73 m(2) (P=0.75). There was no significant difference in the annual decline in eGFR between the two groups. More patients in the immunosuppression group than in the supportive-care group had severe infections, impaired glucose tolerance, and weight gain of more than 5 kg in the first year of treatment. One patient in the immunosuppression group died of sepsis.

CONCLUSIONS

The addition of immunosuppressive therapy to intensive supportive care in patients with high-risk IgA nephropathy did not significantly improve the outcome, and during the 3-year study phase, more adverse effects were observed among the patients who received immunosuppressive therapy, with no change in the rate of decrease in the eGFR. (Funded by the German Federal Ministry of Education and Research; STOP-IgAN ClinicalTrials.gov number, NCT00554502.).

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).