Prognosis and risk factors for idiopathic membranous nephropathy with nephrotic syndrome in Japan

Risk factors and predictive model for renal outcomes in autoimmune membranous nephropathy with and without acute kidney injury: a retrospective cohort study

Objective

This study aimed to delineate the risk factors affecting renal outcomes in autoimmune membranous nephropathy (aMN) with or without acute kidney injury (AKI) and develop a predictive model.

Methods

This retrospective cohort study included 441 patients with biopsy-confirmed aMN from the First Affiliated Hospital of Fujian Medical University (January 2010 to March 2023). Patients were grouped based on the presence of AKI and followed up until a renal endpoint event (progression to end-stage renal disease, initiation of dialysis, or either a >40% decline in estimated glomerular filtration rate from baseline or a doubling of serum creatinine levels from baseline, both sustained for ≥3 months) or study endpoint (March 2024). Clinicopathological and renal outcomes were collected and analyzed. Risk factors for renal endpoints were identified via Cox regression analyses, and a nomogram was constructed. Model performance was evaluated using the C-index, time-dependent receiver operating characteristic (Time-ROC) curves, calibration curves, and decision curve analysis (DCA). Kaplan-Meier survival curves compared renal survival between AKI subgroups.

Results

Among 441 patients, 109 (24.72%) experienced AKI. Renal endpoint events occurred in 40.4% of the AKI group and 4.5% of the non-AKI group. Multivariate Cox regression identified AKI (HR = 7.298, P < 0.001), triglycerides (HR = 1.140, P = 0.002), serum creatinine (HR = 1.008, P = 0.012), hematuria (HR = 2.246, P = 0.040), and kidney anti-M-type phospholipase A2 receptor staining 4+ (HR = 2.473, P = 0.003) as independent risk factors, while serum C3 (HR = 0.082, P < 0.001) was an independent protective factor. The nomogram had a C-index of 0.845 (P < 0.001), with Time-ROC AUCs of 0.92, 0.81, 0.83, and 0.87 for 3 to 6 years, respectively. Calibration plots revealed good consistency between the predicted and actual probabilities. DCA indicated that the nomogram had potential clinical utility. Kaplan-Meier analysis showed lower cumulative renal survival in patients with AKI (P < 0.001).

Conclusions

The risk factor model suggests that renal outcomes in patients with aMN can be predicted. Early assessment and management targeting these identified risk factors could help delay renal function decline in these patients.

Efficacy and safety of ripertamab for treating primary membranous nephropathy among adults: a multicenter, retrospective, real-world study

Background

Ripertamab has been used in an off-label manner for treating primary membranous nephropathy (PMN) in real-world settings in China, despite limited evidence supporting the efficacy of this drug. This multicenter, retrospective study is the first to assess the effectiveness and safety of ripertamab for treating PMN in a real-world Chinese clinical setting.

Methods

Adult patients with PMN who were treated with at least one course of ripertamab alone were included in this study. Patients were categorized into two groups based on their prior treatment of PMN: the initial therapy group and the non-initial therapy group. The primary outcome was the occurrence of complete remission (CR) or partial remission (PR) at 6 and 12 months. The secondary outcomes included the time to achieve remission, relapse rate and the incidence of adverse events (AEs).

Results

Fifty-two patients were ultimately included for analysis. Among these patients, 39 received ripertamab as initial therapy, while 13 were in the non-initial therapy group. The median follow-up duration was 8.7 (4.7, 11.3) months. At 6 months, 24/40 (60.0%) patients achieved clinical remission, with 2/40 (5.0%) achieving CR and 22/40 (55.0%) achieving PR. At 12 months, 22 patients completed follow-up: 2 (9.1%) achieved CR, and 15 (68.2%) achieved PR. The median time to remission for the entire cohort was 90.5 (32, 165) days and four of the 52 patients (7.7%) relapsed. The initial therapy group had a higher remission rate at 12 months than the non-initial therapy group [13/15 (86.7%) vs. 4/7 (57.1%)]. Additionally, the initial therapy group achieved remission more quickly than the non-initial therapy group [79.0 (36, 112) vs. 165.0 (30, 313) days]. Ripertamab was well tolerated, with 9.6% (5/52) of patients experiencing AEs; none of the AEs were severe.

Conclusion

Ripertamab demonstrated efficacy and good tolerability for the treatment of PMN in a Chinese real-world setting. These findings support the use of ripertamab as a therapeutic option for PMN patients and suggest the need for further investigation into its long-term safety and efficacy.

Randomised, double-blind study to evaluate the efficacy of rituximab in the treatment of idiopathic membranous nephropathy: A clinical trial protocol

In Japan, corticosteroid monotherapy has traditionally been recommended as the first-line therapy for membranous nephropathy with nephrotic syndrome. In contrast, except for Japan, rituximab is recommended as the first-line therapy for membranous nephropathy with nephrotic syndrome. This clinical trial aimed to verify the efficacy and safety of the intravenous administration of rituximab without steroids or immunosuppressants as an induction therapy in Japanese patients with idiopathic membranous nephropathy and nephrotic syndrome. This was a multicentre (15 in Japan), placebo-controlled, randomized, double-blind, parallel-group comparative study. A total of 88 patients diagnosed with idiopathic membranous nephropathy and nephrotic syndrome were randomly allocated to rituximab and placebo groups in a 1:1 ratio; rituximab 1,000 mg or placebo IV infusion was administered every 2 weeks for two doses in a double-blinded manner. The primary endpoint was the percentage of patients achieving less than 1.0 g/g creatinine in urine protein/creatinine ratio in random urine at 26 weeks after the first administration of rituximab or placebo. This study was approved by the institutional review boards and conducted in accordance with the Good Clinical Practice guidelines. This study was registered at ClinicalTrials.gov, NCT05914155 and the Japan Registry of Clinical Trials, jRCT2041230037 on 13 June 2023.

Randomized Prospective Controlled Open-labeled Trial of Cyclosporine with/without Low-dose Oral Corticosteroids in Idiopathic Membranous Nephropathy in Adults with Nephrotic Syndrome

Objective We conducted a prospective, randomized controlled, open-label study to investigate the efficacy of a combination of cyclosporine and low-dose prednisolone in patients with idiopathic membranous nephropathy (IMN). Methods We recruited biopsy-proven IMN patients with nephrotic syndrome who had never been treated with immunosuppressants. The patients were randomized into 2 groups treated after randomization with cyclosporine (3 mg/kg/day) alone or with an oral low-dose corticosteroid (prednisolone 15 mg/day) for 24 months. Results We recruited 30 patients with IMN and nephrotic-range proteinuria, 28 of whom were included in this study. Fourteen patients were randomized for treatment with only cyclosporine (Group A), and 14 were randomized for treatment with cyclosporine plus low-dose corticosteroids (Group B). Cyclosporine monotherapy induced remission in 12 of the 14 patients in Group A, including partial remission in 7 patients (50.0%) and complete remission in 5 patients (36.7%). In Group B, 12 of 14 patients achieved proteinuria remission, including 11 (78.6%) with complete remission and 1 (7.1%) with partial remission. Although there was no marked difference in the overall remission rate, the complete remission rate was significantly higher in Group B than in Group A (p=0.02). Furthermore, there was a statistically significant difference between the groups in the time from the start of the study to complete remission (10.2±7.8 months in Group A; 9.5±6.1 months in Group B, p=0.03). Conclusion The combination of cyclosporine and low-dose corticosteroid treatment is an effective and important option in the management of patients with IMN with nephrotic-range proteinuria, either as an initial therapy or as a long-term treatment.

Lupus-like membranous nephropathy during the postpartum period expressing glomerular antigens exostosin 1/exostosin 2 and phospholipase A2 receptor: a case report

Recently, several target antigens of membranous nephropathy (MN), such as phospholipase A2 receptor (PLA2R) and exostosin 1/exostosin 2 (EXT1/2), have been discovered. A 30-year-old woman was referred to our hospital with nephrotic range proteinuria and microscopic hematuria. She was first noted to have proteinuria before pregnancy, and her proteinuria worsened in the postpartum period. A renal biopsy showed MN. Immunofluorescence microscopy showed IgG, IgA, IgM, C3, C4, and C1q depositions in the mesangial area and glomerular capillary walls (GCWs). Regarding the IgG subclass, IgG1 and IgG3 were detected on glomeruli. Electron microscopy showed subepithelial electron-dense deposits (EDDs). EDDs were also detected in paramesangial and subendothelial areas. The diagnosis of membranous lupus nephritis (MLN) was suspected, but she did not fulfill the criteria for systemic lupus erythematosus. Neither anti-nuclear antibody nor hypocomplementemia were detected. We further evaluated glomerular EXT1/2 expressions, which were evident on GCWs. In addition, PLA2R was also detected on GCWs, although serum antibody for PLA2R was negative. She responded to immunosuppressive therapy with decreased proteinuria. In the present case, glomerular PLA2R expression implied the possibility of primary MN. However, pathological findings with a full-house staining pattern and glomerular EXT1/2 expressions were very similar to those of lupus-associated MN. Glomerular PLA2R expression appeared not to reflect immunocomplexes of PLA2R and autoantibody when considering the results for glomerular IgG subclass and the absence of serum anti-PLA2R antibody. Collectively, it is plausible that this was a case of a relatively young postpartum female who developed latent MLN rather than primary MN.

Treatment of Membranous Nephropathy in Chinese Patients: Comparison of Rituximab and Intravenous Cyclophosphamide with Steroids

Introduction

Previous studies have shown that rituximab (RTX) and cyclic oral corticosteroid-cyclophosphamide (CTX) regimens have similar effects on primary membranous nephropathy (PMN). However, no studies have compared RTX with an intravenous CTX regimen, which is more commonly used in China and requires fewer cumulative CTX doses.

Methods

We prospectively assigned 141 PMN patients with baseline proteinuria ≥4 g/24 h, serum albumin <30 g/L, and eGFR ≥30 mL/min × 1.73 m2 despite at least 3 months of treatment with ACEI and/or ARB to the RTX group (375 mg/m2 per injection per week × 4 injections) or to the CTX group (prednisone 0.8 mg/kg/day and intravenous CTX 500 mg/m2 per month until the total dose reached 6-8 g). The primary endpoint was defined as a combination of partial remission or complete remission at 12 months.

Results

By the end of 12 months, 43 of 70 patients (61.43%) in the RTX group and 54 of 71 patients (76.06%) in the CTX group reached the primary endpoint (p = 0.06). Significantly fewer patients in the RTX group achieved complete remission than the CTX group (14.29% vs. 33.80%, p = 0.01). The adverse events rate was similar between the RTX group and the CTX group (28.57% vs. 40.85%, p = 0.13). In subgroup analysis, we found that fewer patients from the RTX group achieved the primary endpoint than the CTX group (48.65% vs. 74.29%, p = 0.03) among patients with massive proteinuria (urine protein ≥8 g/24 h). During the observational phase, 61 patients in the RTX group and 58 in the CTX group completed 24 months of follow-up, exhibiting similar remission rates (RTX vs. CTX: 75.41% vs. 68.97%, p = 0.54).

Conclusions

Our results show that the intravenous CTX regimen has similar safety and efficacy with higher rates of early complete remission than RTX in the treatment of PMN patients.

New-onset Kidney Biopsy-proven Membranous Nephropathy Induced End-stage Kidney Disease in a Living Donor

Thirteen years after kidney donation, a 70-year-old man was referred to a nephrologist because of proteinuria. The serum creatinine, albumin, and urinary protein levels were 2.39 mg/dL, 3.0 g/dL, and 6.72 g/gCr, respectively. A kidney biopsy revealed thickening of the glomerular basement membrane with sub-epithelial deposits, suggesting membranous nephropathy. Considering the apparent interstitial fibrosis and diffuse glomerulosclerosis, supportive treatment was chosen. However, 11 months after the kidney biopsy, hemodialysis was required. The present case constitutes an important teaching point, as glomerular disease can occur in living donors and require careful and long-term medical checkup examinations.

Clinicopathological characteristics of neural epidermal growth factor-like 1 protein-associated membranous glomerulonephritis

Neural epidermal growth factor-like 1 protein (NELL1) is the second most common target antigen in membranous glomerulonephritis (MGN). However, data regarding the clinicopathological characteristics of NELL1-associated MGN are limited owing to its low prevalence. This study examined the prevalence and clinicopathological characteristics of NELL1-associated MGN in a Japanese cohort. Additionally, we compared the clinicopathological features of NELL1-positive MGN, phospholipase A2 receptor 1 (PLA2R1)-positive MGN, and MGN negative for all three antigens (NELL1, PLA2R1, and thrombospondin type-1 domain-containing 7A). Among 257 consecutive patients pathologically diagnosed with MGN at two centers in Japan, 24 (9.3%) were immunohistochemically positive for NELL1. Clinically, patients with NELL1-positive MGN were significantly older (p < 0.001) and had a higher frequency of bucillamine use (vs PLA2R1-positive MGN, p < 0.01). Histologically, NELL1-positive MGN exhibited significantly lower detection of spikes and crater formation (p < 0.001), higher prevalence of segmental spike distribution (vs PLA2R1-positive MGN: p < 0.001), and higher prevalence of stage I cases on electron microscopy (p < 0.01). There were no significant differences in the prognoses among the three groups. The characteristic histological feature of segmental distribution in NELL1-positive MGN may be related to bucillamine use and the early phase of the disease. Further investigations with larger numbers of patients may offer further insight into the prognosis of patients with NELL1-positive MGN.

[Idiopathic membranous nephropathy with focal segmental sclerosis]

AIM

To evaluate the clinical and pathological features and prognosis of idiopathic membranous nephropathy (IMN) with focal segmental sclerosis (FSGS) in a group of Russian patients.

MATERIALS AND METHODS

101 patients with morphologically verified IMN were enrolled in our single-center cohort retrospective study. The patients were divided into IMN group and IMN+FSGS group. The primary and secondary outcomes were analyzed in 59 patients, which had follow-up data for period more than 6 months.

RESULTS

At the time of renal biopsy the median age was 46.0 (33.0; 55.0) years and the median follow-up was 6.8 (4.0; 15.6) months. Secondary FSGS was revealed in 15 (14.9%) patients with IMN. The IMN and IMN+FSGS groups did not differ in gender, age of onset IMN and age of renal biopsy. In the IMN+FSGS group proteinuria was higher and estimated glomerular filtration rate was lower than that in the IMN group (p<0.05). The systolic arterial pressure and creatinine levels in the IMN+FSGS group were slightly higher than in the IMN group, but the difference was not significant. Anti-PLA2R positivity was similar in both groups. Chronic kidney disease (CKD) progression was observed in 10/52 (19.2%) and 5/7 (71.4%) patients in IMN and IMN+FSGS groups, respectively. In a multivariate Cox regression model, age of renal biopsy (odds ratio - OR 1.12, 95% confidence interval - CI 1.03-1.22; р=0.07), FSGS (OR 0.05, 95% CI 0.01-0.34; р=0.002) и response to initial course of immunosuppression (OR 0.33, 95% CI 0.12-0.95; р=0.039) were associated with the CKD progression.

CONCLUSION

In patients with IMN secondary FSGS is associated with a greater severity of proteinuria and a decrease in estimated glomerular filtration rate, and is also an independent factor of the CKD progression.

Combined evaluation of glomerular phospholipase A2 receptor and immunoglobulin G subclass in membranous nephropathy

Background

Phospholipase A2 receptor (PLA2R) is a major target antigen in idiopathic membranous nephropathy (MN). Anti-PLA2R antibodies are mainly of the immunoglobulin G (IgG) subclass IgG4, although other IgG subclass depositions in glomeruli may also be detected. However, the importance of the subclass of the IgG deposit has not been proven. Thus we investigated clinical findings from patients with idiopathic MN in relation to glomerular PLA2R deposition and IgG subclass.

Methods

We enrolled 132 Japanese patients with biopsy-proven idiopathic MN in a multicentre retrospective observational study. We investigated the complete remission rate as the primary outcome and the development of end-stage kidney disease (ESKD) as the secondary outcome in relation to glomerular PLA2R deposition. Moreover, we evaluated prognostic factors, including glomerular IgG subclass, in the PLA2R-positive group.

Results

The percentage of cases with glomerular PLA2R deposition was 76.5% (n = 101). The first complete remission rate of the PLA2R-positive group was worse than that of the PLA2R-negative group (logrank test P < .001). ESKD incidence did not significantly differ between the glomerular PLA2R-negative and PLA2R-positive MN groups (logrank test P = .608). In the PLA2R-positive group, higher PLA2R intensities and IgG2 staining were associated with a poorer first complete remission rate (logrank test P < .001 and P = .032, respectively). Cox proportional hazards analysis also showed that strong PLA2R deposition and positive IgG2 staining were significantly associated with a failure to reach complete remission [hazard ratio 2.09 (P = .004) and 1.78 (P = .030), respectively].

Conclusions

Our results suggest that intense glomerular PLA2R and IgG2 positivity predict a poor proteinuria remission rate in idiopathic MN.

Aggressive treatment may be needed for idiopathic membranous nephropathy with focal segmental glomerulosclerosis lesions

OBJECTIVE

The purpose of this study was to analyze the clinical, pathological, prognostic features and treatment response of the coexistence of focal segmental glomerulosclerosis lesions with idiopathic membranous nephropathy.

METHODS

This is a two-center retrospective cohort study. Patients of idiopathic membranous nephropathy were enrolled and divided into two groups with or without focal segmental glomerulosclerosis lesions according to the renal biopsy. Laboratory data and pathological manifestation were compared. Renal phospholipase A2 receptor was detected by immunofluorescence. During the follow-up, the effects of different therapies and renal function were estimated.

RESULTS

A total of 236 patients were finally enrolled in this study, of which 60 and 176 idiopathic membranous nephropathy patients were enrolled in the FSGS+ and FSGS- groups, respectively. The FSGS+ group showed a higher percentage of hypertension history (38.3 vs. 20.0%, p=0.004), with a significantly higher level of systolic pressure [137 (120, 160) mmHg vs. 130 (120, 140) mmHg, p=0.009]. Main laboratory findings, including serial albumin (20.4±7.8 g/L vs. 24.5±6.7 g/L, p<0.001), 24-h proteinuria [5.61 (3.10, 7.87) g/day vs. 3.82 (2.31, 5.79) g/day, p=0.002], serial creatinine [80.8 (65.8, 97.9) μmol/L vs. 72.0 (58.7, 84.9) μmol/L, p=0.003], and estimated glomerular filtration rate [86 (66, 101) mL/min/1.73 m2 vs. 95 (81, 108) mL/min/1.73 m2, p=0.007] showed significant differences between the two groups. Pathologically, patients with focal segmental glomerulosclerosis lesions appeared with a higher percentage of crescents, a more severe degree of interstitial fibrosis, and a higher level of membranous nephropathy stage. Renal phospholipase A2 receptor showed a relatively lower positive rate of only 75.0% in the FSGS+ group in comparison with the positive rate of 90.3% in the FSGS- group (p=0.031). The prognosis was generally similar between the two groups. Among patients who were given non-immunosuppression treatment, those with focal segmental glomerulosclerosis lesions took a relatively longer period of time to achieve complete remission (29.3±7.0 m vs. 15.4±8.9 m, p=0.025) and experienced a higher rate of renal function deterioration (37.5 vs. 5.4%, p=0.033) compared with the other ones. While among those receiving immunosuppression treatment, both groups received similar remission rates.

CONCLUSION

Compared with FSGS- group, idiopathic membranous nephropathy with focal segmental glomerulosclerosis lesions represented more severe nephrotic syndrome and worse renal function. In view of the renal function decline during the follow-up, more aggressive treatment with the use of immunosuppressants should be considered for idiopathic membranous nephropathy patients with focal segmental glomerulosclerosis lesions.

Fractional excretion of total protein predicts renal prognosis in Japanese patients with primary membranous nephropathy

Background

Primary membranous nephropathy (pMN) is one of the most common types of glomerulonephritis, with a third of patients progressing to renal insufficiency. Various prognostic factors have been reported, of which urinary protein and renal function are the most critical parameters. Fractional excretion of total protein (FETP) indicates protein leakage that accounts for creatinine kinetics and serum protein levels. In this study, we investigated the association between FETP and renal prognosis in pMN.

Methods

We retrospectively identified 150 patients with pMN. FETP was calculated as follows: (serum creatinine × urine protein)/(serum protein × urine creatinine) %. We divided the patients into three groups according to FETP values and compared the clinicopathological findings. The primary outcome was an estimated glomerular filtration rate (eGFR) decrease of ≥30% from the baseline level.

Results

FETP was associated with urinary protein and renal function, Ehrenreich and Churg stage, and global glomerulosclerosis. The primary outcome was observed in 38 patients (25.3%), and the frequency of the primary outcome was higher in the high FETP group (P = .001). FETP is higher than protein-creatinine ratio (PCR) in the area under the curve. In the multivariate analysis adjusted for age, eGFR, PCR and treatment, FETP was significantly associated with primary outcome (adjusted hazard ratio, 8.19; P = .019).

Conclusions

FETP is a valuable indicator that can reflect the pathophysiology and is more useful than PCR as a predictor of renal prognosis in patients with Japanese pMN.

Combined Serologic and Genetic Risk Score and Prognostication of Phospholipase A2 receptor-Associated Membranous Nephropathy

INTRODUCTION

The aim of this study was to test whether a combined risk score on the basis of genetic risk and serology can improve the prediction of kidney failure in phospholipase A2 receptor (PLA2R)-associated primary membranous nephropathy.

METHODS

We performed a retrospective analysis of 519 biopsy-proven PLA2R-associated primary membranous nephropathy patients with baseline eGFR ≥25 ml/min per 1.73 m 2 . The combined risk score was calculated by combining the genetic risk score with PLA2R ELISA antibody titers. The primary end point was kidney disease progression defined as a 50% reduction in eGFR or kidney failure. Cox proportional hazard regression analysis and C-statistics were applied to compare the performance of PLA2R antibody, genetic risk score, and combined risk score, as compared with clinical factors alone, in predicting primary outcomes.

RESULTS

The median age was 56 years (range, 15-82 years); the male-to-female ratio was 1:0.6, the median eGFR at biopsy was 99 ml/min per 1.73 m 2 (range: 26-167 ml/min per 1.73 m 2 ), and the median proteinuria was 5.3 g/24 hours (range: 1.5-25.8 g/24 hours). During a median follow-up of 67 (5-200) months, 66 (13%) had kidney disease progression. In Cox proportional hazard regression models, PLA2R antibody titers, genetic risk score, and combined risk score were all individually associated with kidney disease progression with and without adjustments for age, sex, proteinuria, eGFR, and tubulointerstitial lesions. The best-performing clinical model to predict kidney disease progression included age, eGFR, proteinuria, serum albumin, diabetes, and tubulointerstitial lesions (C-statistic 0.76 [0.69-0.82], adjusted R 2 0.51). Although the addition of PLA2R antibody titer improved the performance of this model (C-statistic: 0.78 [0.72-0.84], adjusted R 2 0.61), replacing PLA2R antibody with the combined risk score improved the model further (C-statistic: 0.82 [0.77-0.87], adjusted R 2 0.69, difference of C-statistics with clinical model=0.06 [0.03-0.10], P < 0.001; difference of C-statistics with clinical-serologic model=0.04 [0.01-0.06], P < 0.001).

CONCLUSIONS

In patients with PLA2R-associated membranous nephropathy, the combined risk score incorporating inherited risk alleles and PLA2R antibody enhanced the prediction of kidney disease progression compared with PLA2R serology and clinical factors alone.

Urine albumin-to-creatinine ratio diurnal variation rate predicts outcomes in idiopathic membranous nephropathy

BACKGROUND

Idiopathic membranous nephropathy (IMN) is a leading cause of end-stage renal disease (ESRD). The purpose of this study was to evaluate whether urinary albumin-to-creatinine ratio (UACR) diurnal variation rate calculated by spot urinary protein test predicts 1-year nephrotic outcomes as a biomarker of proteinuria severity in patients with IMN.

METHODS

Patients' baseline demographics, blood and urinary biomarkers, and clinical and pathological characteristics were collected retrospectively. Urine samples were collected at 7:00 (before breakfast) and 19:00 (after dinner) to calculate the UACR diurnal variation rate. A prediction model for no remission (NR) was developed statistically based on differences between prognosis groups. Receiver operating characteristic curve (ROC) analysis was performed to evaluate prediction abilities and determine optimal cut-off points of the model and UACR diurnal variation rate alone.

RESULTS

The formula for calculating the probability of NR was exp(L)/(1 + exp(L)), where the linear predictor L =  - 22.038 + 0.134 × Age (years) + 0.457 × 24-h urinary protein + 0.511 × blood urea nitrogen (BUN) + 0.014 × serum uric acid (SUA) + 2.411 if glomerular sclerosis + 0.816 × fasting blood glucose (FBG)-0.039 × UACR diurnal variation rate (%). Optimal cut-off points for NR prediction by the final model and UACR diurnal variation rate alone were 0.331 and 58.5%, respectively. Sensitivity and specificity were 0.889 and 0.859 for the final model, and 0.926 and 0.676 for UACR diurnal variation rate alone.

CONCLUSION

UACR diurnal variation using spot urinary protein is a simpler way to predict nephrotic outcomes and is a highly sensitive screening tool for identifying patients who should undergo further comprehensive risk assessment.

Practice patterns of rituximab for primary membranous nephropathy 2021 in Japan: a web-based survey of board-certified nephrologists

BACKGROUND

Although rituximab (RTX) is recommended by kidney disease improving global outcomes as one of the standard therapies for primary membranous nephropathy (pMN), given the constraint of insurance coverage, it is not clear how the drug is used in Japan.

METHODS

This cross-sectional study was conducted via a web-based survey between November and December 2021. The participants were certified nephrologists and recruited through convenience sampling. Experience with RTX for pMN was compared to experience with RTX for minimal change nephrotic syndrome (MCNS). Reasons for withholding RTX for pMN, even when it is indicated, were also investigated. Furthermore, the proportion difference in RTX experience was analyzed.

RESULTS

Responses from 380 nephrologists across 278 facilities were analyzed. RTX was used for pMN by 83 (21.8%), which was less than the 181 (47.6%) who had used RTX for MCNS (ratio of proportions: 0.46). RTX use for pMN was more frequent in facilities performing 41-80 and 81 or more kidney biopsies annually (vs. none) and by physicians with experience in anti-PLA2R antibody measurement. RTX administration for pMN was covered by insurance for 56 (67.5%), was facility-paid for 10 (12.0%), and was copaid by patients for 6 (7.2%). The most common reason for withholding RTX for pMN was difficulty in ensuring financing (146, 79.3%).

CONCLUSIONS

RTX use for pMN is less common than for MCNS but not infrequent. Treatment with RTX was more frequent in biopsy-intensive facilities, and it was fully paid by the facility or patient in one-fifth of cases.

Underlying Mechanisms and Treatment of Hypertension in Glomerular Diseases

PURPOSE OF REVIEW

This review aims to explore the underlying mechanisms that lead to hypertension in glomerular diseases and the advancements in treatment strategies and to provide clinicians with valuable insights into the pathophysiological mechanisms and evidence-based therapeutic approaches for managing hypertension in patients with glomerular diseases.

RECENT FINDINGS

In recent years, there have been remarkable advancements in our understanding of the immune and non-immune mechanisms that are involved in the pathogenesis of hypertension in glomerular diseases. Furthermore, this review will encompass the latest data on management strategies, including RAAS inhibition, endothelin receptor blockers, SGLT2 inhibitors, and immune-based therapies. Hypertension (HTN) and cardiovascular diseases are leading causes of mortality in glomerular diseases. The latter are intricately related with hypertension and share common pathophysiological mechanisms. Hypertension in glomerular disease represents a complex and multifaceted interplay between kidney dysfunction, immune-mediated, and non-immune-mediated pathology. Understanding the complex mechanisms involved in this relationship has evolved significantly over the years, shedding light on the pathophysiological processes underlying the development and progression of glomerular disease-associated HTN, and is crucial for developing effective therapeutic strategies and improving patients' outcomes.

Machine learning model to estimate probability of remission in patients with idiopathic membranous nephropathy

BACKGROUND

Idiopathic membranous nephropathy (IMN) is a type of nephrotic syndrome and the leading cause of chronic kidney disease. As far as we know, no predictive model for assessing the prognosis of IMN is currently available. This study aims to establish a nomogram to predict remission probability in patients with IMN and assists clinicians to make treatment decisions.

METHODS

A total of 266 patients with histopathology-proven IMN were included in this study. Least absolute shrinkage and selection operator regression was utilized to identify the most important variables. Subsequently, multivariate Cox regression analysis was conducted to construct a nomogram, and bootstrap resampling was employed for internal validation. Receiver operating characteristic and calibration curves and decision curve analysis (DCA) were utilized to assess the performance and clinical utility of the developed model.

RESULTS

A prognostic nomogram was established, which incorporated creatinine, glomerular_basement_membrane_thickening, gender, IgG_deposition, low-density lipoprotein cholesterol, and fibrinogen. The areas under the curves of the 3-, 12-, 24-month were 0.751, 0.725, and 0.830 in the training set, and 0.729, 0.730, and 0.948 in the validation set respectively. These results and calibration curves demonstrated the good discrimination and calibration of the nomogram in the training and validation sets. Additionally, DCA indicated that the nomogram was useful for remission prediction in clinical settings.

CONCLUSION

The nomogram was useful for clinicians to evaluate the prognosis of patients with IMN in early stage.

Updated evidence of beneficial effect of LDL apheresis for refractory nephrotic syndrome due to a variety of causative diseases for nationwide and global approval

Low-density lipoprotein apheresis (LDL-A) therapy has shown reasonable efficacy in treating nephrotic syndrome (NS) refractory to initial drug therapy and has been covered by National Health Insurance for the indication of drug-resistant focal segmental glomerulosclerosis (FSGS) since 1992 in Japan and has contributed to liberating substantial number of patients of this disease from entering into end-stage renal disease by easier practical application in actual clinical settings. Subsequently, various beneficial evidence of this treatment has accumulated on those other than FSGS, however, due to the limitation of covered disease insurance only for FSGS, patients with diseases other than FSGS are unlikely to benefit from this treatment in practice. This review summarizes the therapeutic evidence of the beneficial effect of LDL-A accumulated to date and the mechanisms of action analyzed from multifaceted perspectives. examines the applicability of expanding insurance coverage for diseases other than FSGS.

Clinical characteristics and prognosis of patients with idiopathic membranous nephropathy with kidney tubulointerstitial damage

BACKGROUND

To investigate the clinical and kidney pathological features and prognosis of idiopathic membranous nephropathy (IMN) with kidney tubulointerstitial damage (TID).

METHODS

Based on the presence or absence of kidney TID by kidney biopsy, 300 patients diagnosed with IMN were categorized into non-TID (TID-) and tubulointerstitial injury (TID+) groups. The clinical and pathological data were analyzed retrospectively. All patients were followed up for 6-24 months after treatment with glucocorticoids (GCs) combined with cyclophosphamide or GCs combined with calcineurin inhibitors (CNIs) to observe treatment effects on patient prognosis.

RESULTS

The patients in the TID + group were older and more likely to be male. The 24-h urine protein, blood urea nitrogen, serum creatinine, cystatin C, β2-microglobulin, and antiphospholipase A2 receptor antibody levels were higher than those in the TID - group and the pathological manifestations were more severe. After 1 year of follow-up, the overall response rate (complete response + partial response) in the TID + group was lower (66.67% vs. 80.89%, p = .022) than in the other. After combined GC and CNI therapy, the complete remission rate in the TID + group was significantly lower than that in the TID - group (13.79% vs. 35.46%, p = .022). The 24-h urine protein level was an independent risk factor for worsening kidney condition (p = .038).

CONCLUSION

Patients with IMN with TID have more severe clinical manifestations and pathological damage and lower remission rates. IMN with TID is a risk factor for worsening kidney condition; however, it is not an independent risk factor.

Correlation Analysis between Intrarenal Small Artery Intimal Thickening and Clinicopathological Features and Prognosis in Primary Membranous Nephropathy Patients

BACKGROUND

Primary membranous nephropathy (PMN) is the most common pathological type of nephrotic syndrome in adults. Intrarenal small artery intimal thickening can be observed in most renal biopsies. The purpose of this study was to investigate the association between intrarenal small artery intimal thickening and clinicopathological features and prognosis in PMN patients.

METHODS

Data were continuously collected from patients who were diagnosed with PMN in Shenzhen Second People's Hospital (The First Affiliated Hospital of Shenzhen University) from 2008 to 2021 for a retrospective cohort study. Regression analysis and survival analysis were used to analyze the relationship between intrarenal small artery intimal thickening and renal prognosis in PMN patients.

RESULTS

300 PMN patients were enrolled in this study, including 165 patients (55%) with intrarenal small artery intimal thickening. Patients with intimal thickening were older, with higher BMI, systolic blood pressure and diastolic blood pressure, serum uric acid, a higher proportion of hypertension, acute kidney injury, nephrotic syndrome, more urine protein, and lower eGFR. Multivariate Cox regression analysis showed that after adjusting for age, gender, hypertension, BMI, urine protein, eGFR, and the use of ACEI/ARB and hormone immunosuppressants, intimal thickening was a risk factor for renal prognosis in PMN patients (HR = 3.68, 95% CI 1.36-9.96, p < 0.05). Kaplan-Meier survival curve analysis showed that the incidence of reaching the renal composite outcome was higher in the intimal thickening group (p < 0.05).

CONCLUSION

The prognosis of PMN patients with intrarenal small artery intimal thickening is worse, so early intervention is very important for these patients.

Single-Nephron GFR in Different Glomerular Basement Membrane Stages of Membranous Nephropathy

Key Points

The first study that estimated single-nephron GFR (SNGFR) in patients with membranous nephropathy (MN). Associations of SNGFR with MN staging by electron microscopy and clinicopathologic findings were cross-sectionally investigated. This study illustrates a role for disease-specific GBM structural lesions as determinants of SNGFR in patients with MN.

Background

Alterations in single-nephron dynamics have been demonstrated in animal models of membranous nephropathy (MN). This study applied a recently developed technique to estimate single-nephron parameters in human MN.

Methods

Single-nephron GFR (SNGFR) and single-nephron urinary protein excretion (SNUPE) were calculated by dividing total GFR and UPE by the total estimated number of nonglobally sclerotic glomeruli (NSG). The NSG number per kidney was estimated using cortical volume assessment and biopsy-based stereology. MN staging by electron microscopy was performed using Ehrenreich-Churg (EC) criteria. Single-nephron parameters were analyzed in relation to clinicopathological factors known to associate with disease outcomes.

Results

The study included 109 patients with MN (mean age 65 years; 73% male; eGFR 62 ml/min, 36% on renin-angiotensin-aldosterone system inhibitors prebiopsy). EC stages were I, 19%; II, 49%; III, 26%; and IV, 6%. There was no difference in glomerular volume among EC stage groups. With advancing EC stage, SNGFR and SNUPE decreased from mean 56–42 nl/min and 5.1–3.8 µ g/d, respectively. In multivariable models, EC stage was associated with SNGFR even after adjustment for key clinicopathological factors, such as reduced GFR, serum albumin, UPE, segmental glomerulosclerosis, chronic tubulointerstitial damage, and prebiopsy use of renin-angiotensin-aldosterone system inhibitors. By contrast, EC stage was not associated with glomerular volume and SNUPE after multivariable adjustment.

Conclusions

These results provide the first clinical evidence of alterations in single-nephron dynamics with advancing EC stage of human MN and support a role for disease-specific glomerular basement membrane structural lesions as determinants of SNGFR.

Prognosis and incidence of infections in chronic kidney disease patients with membranous nephropathy enrolled in a large Japanese clinical claims database

BACKGROUND

The treatment of membranous nephropathy involves a combination of conservative approaches, steroids, and immunosuppressive agents. Infection is an adverse effect of these treatments and its incidence is a critical issue for patients with membranous nephropathy, as many of them are older adults. However, the incidence of infections remains unclear; hence, this study investigated this issue using data from a large Japanese clinical claims database.

METHODS

From a database of patients with chronic kidney disease (n = 924,238), those diagnosed with membranous nephropathy from April 2008 to August 2021 with a history of one or more prescriptions and undergoing medical care were included. Patients who had undergone kidney replacement therapy were excluded. Patients were divided into three groups based on their prescriptions after diagnosis: prednisolone(PSL), who received steroids; PSL + IS, who were prescribed steroids and immunosuppressive agents; and C, who were treated without steroid or immunosuppressive agent use. The primary outcome was death or the initiation of kidney replacement therapy. The secondary outcome was death or hospitalization due to infection. Infectious diseases such as sepsis, pneumonia, urinary tract infections, cellulitis, cytomegalovirus infection, colitis, or hepatitis were defined as infections. Hazard ratios were expressed using group C as a reference.

RESULTS

Of 1,642 patients, the incidence of the primary outcome occurred in 62/460 individuals in the PSL group, 81/635 individuals in the PSL + IS group, and 47/547 individuals in the C group. The Kaplan-Meier survival curve showed no significant differences (P = 0.088). The incidence of secondary outcomes occurred in 80/460 individuals, 102/635 individuals, and 37/547 individuals in the PSL, PSL + IS, and C groups, respectively. The incidence of secondary outcomes was significantly higher in the PSL group (hazard ratio [HR] 2.43 [95% confidence interval [CI] 1.64-3.62, P < 0.01]) and PSL + IS group (HR 2.23 [95% CI 1.51-3.30, P < 0.01]).

CONCLUSIONS

The outcome of membranous nephropathy was not completely satisfactory. Patients who use steroids and immunosuppressive agents have a high incidence of infection and may require close monitoring during the course of treatment.High-efficacy treatment with a low incidence of infections is desirable. The significance of this study lies in the fact that the impressions of membranous nephropathy, which have been recognized as tacit knowledge, were quantified using a clinical database.

Deep learning analysis of clinical course of primary nephrotic syndrome: Japan Nephrotic Syndrome Cohort Study (JNSCS)

BACKGROUND

Prognosis of nephrotic syndrome has been evaluated based on pathological diagnosis, whereas its clinical course is monitored using objective items and the treatment strategy is largely the same. We examined whether the entire natural history of nephrotic syndrome could be evaluated using objective common clinical items.

METHODS

Machine learning clustering was performed on 205 cases from the Japan Nephrotic Syndrome Cohort Study, whose clinical parameters, serum creatinine, serum albumin, dipstick hematuria, and proteinuria were traceable after kidney biopsy at 5 measured points up to 2 years. The clinical patterns of time-series data were learned using long short-term memory (LSTM)-encoder-decoder architecture, an unsupervised machine learning classifier. Clinical clusters were defined as Gaussian mixture distributions in a two-dimensional scatter plot based on the highest log-likelihood.

RESULTS

Time-series data of nephrotic syndrome were classified into four clusters. Patients in the fourth cluster showed the increase in serum creatinine in the later part of the follow-up period. Patients in both the third and fourth clusters were initially high in both hematuria and proteinuria, whereas a lack of decline in the urinary protein level preceded the worsening of kidney function in fourth cluster. The original diseases of fourth cluster included all the disease studied in this cohort.

CONCLUSIONS

Four kinds of clinical courses were identified in nephrotic syndrome. This classified clinical course may help objectively grasp the actual condition or treatment resistance of individual patients with nephrotic syndrome.

Clinical and pathologic features of primary membranous nephropathy in Turkey: a multicenter study by the Turkish Society of Nephrology Glomerular Diseases Working Group

Background

We aimed to evaluate the features of primary membranous nephropathy (MNP) in Turkish people.

Methods

This is a retrospective analysis of patients with biopsy-proven primary MNP. We obtained the data collected between 2009 and 2019 in the primary glomerulonephritis registry of the Turkish Society of Nephrology Glomerular Diseases Study Group (TSN-GOLD). Patients with a secondary cause for MNP were excluded. Clinical, demographic, laboratory, and histopathological findings were analyzed.

Results

A total of 995 patients with primary MNP were included in the analyses. Males constituted the majority (58.8%). The mean age was 48.4 ± 13.9 years. The most common presentation was the presence of nephrotic syndrome (81.7%) and sub nephrotic proteinuria (10.3%). Microscopic hematuria was detected in one-third of patients. The median estimated glomerular filtration rate (eGFR) was 100.6 mL/min/1.73 m² (IQR, 75.4–116.3), and median proteinuria was 6000 mg/d (IQR, 3656–9457). Serum C3 and C4 complement levels were decreased in 3.7 and 1.7% of patients, respectively. Twenty-four (2.4%) patients had glomerular crescents in their kidney biopsy samples. Basal membrane thickening was detected in 93.8% of cases under light microscopy. Mesangial proliferation and interstitial inflammation were evident in 32.8 and 55.9% of the patients, respectively. The most commonly detected depositions were IgG (93%), C3 complement (68.8%), and kappa and lambda immunoglobulin light chains (70%). Although renal functions were normal at presentation, vascular, interstitial, and glomerular findings were more prominent on biopsy in hypertensive patients. No significant effect of BMI on biopsy findings was observed.

Conclusions

Despite some atypical findings, the main features of primary MNP in Turkey were similar to the published literature. This is the largest MNP study to date conducted in Turkish people.

Patterns of biopsy-proven renal diseases in geriatric patients: A single medical center experience

The elderly population is expanding rapidly, and that has become a major healthcare burden in terms of chronic kidney disease. The distribution patterns of kidney diseases in these elderly patients remain largely unclear. Here, we compared biopsy-based renal disease patterns between elderly and nonelderly patients. We performed a single-center, retrospective study (1992-2008) on biopsy-proven renal diseases to compare results between geriatric patients (age ≥ 65 years; n = 254) and nongeriatric patients (18 ≤ age < 65 years; n = 2592). Renal pathology was interpreted by pathologists based on light microscopy, immunofluorescence, and electron microscopy. The ages of the geriatric and nongeriatric groups were 71.8 ± 4.5 (65.1-87.3) and 39.7 ± 17.6 (18-64.9) years, respectively, and 74% and 41% of them, respectively, were men. In the geriatric group, the most frequent diagnosis was membranous nephropathy (46.1%), followed by minimal change disease/focal segmental glomerulosclerosis (16.9%), diabetic nephropathy (8.3%), hypertensive nephrosclerosis (7.5%), and IgA nephropathy (5.9%). The geriatric group had more membranous nephropathy and less lupus nephritis and IgA nephropathy than the nongeriatric group. Furthermore, the 5-year survival rate of the geriatric group was significantly low. Our results demonstrated the different distributions of renal biopsy patterns in geriatric patients diagnosed with acute or chronic progressive kidney injury and proteinuria through renal biopsy.

Efficacy and Safety of Rituximab in the Treatment of Idiopathic Membranous Nephropathy: A Meta-Analysis

Background

Primary membranous nephropathy (MN), sometimes referred to as idiopathic membranous nephropathy (IMN), is a kind of MN whose pathogenesis is yet unclear. According to research reports, the incidence of IMN is about 9.8-26.8%, and it is on the rise.

Methods

The computer retrieves eight databases to obtain controlled trials at home and abroad on the rituximab (RTX) actions in IMN management. After a rigorous literature quality evaluation, software called RevMan 5.3 was used for data analysis.

Results

This meta-analysis finally contained 8 papers. They were all regarded as controlled trials. Six studies reported serum creatinine (standardized mean difference [SMD]: -6.87; 95% CI: -14.09, 0.35; P = 0.062), ALB (SMD: 1.91; 95% CI: -0.31, 4.14; P = 0.092), and adverse reactions (OR: 0.56; 95% CI: 0.36, 0.90; P < 0.01), all of which were significantly higher in the test group than in the control group (OR: 1.37; 95% CI: 1.07, 1.76; P < 0.01).

Conclusion

The overall effective rate, serum creatinine, adverse effects, and ALB of this trial indicate that RTX may be beneficial for individuals with IMN, but further high-quality research is required to confirm these findings.

Non-glomerular Tip Lesion Focal Segmental Glomerulosclerosis as a Negative Predictor in Idiopathic Membranous Nephropathy

Objective

To assess the significance of focal segmental glomerulosclerosis (FSGS) variants on clinicopathological characteristics and short-term outcomes in idiopathic membranous nephropathy (IMN) patients.

Methods

The clinicopathological data of 146 IMN patients diagnosed between December 2016 and March 2019 in our center were collected and analyzed. These patients were divided into the pure IMN group, IMN with glomerular tip lesion (GTL) group, and IMN with non-GTL FSGS group.

Results

The IMN with non-GTL FSGS and IMN with GTL groups both had higher proportions of patients with hypertension, lower serum albumin, and severe proteinuria, while the IMN with non-GTL FSGS group additionally showed higher blood pressure and serum cholesterol, and lower serum IgG than the IMN group (all P<0.05). As for pathology, the IMN with non-GTL FSGS group had higher proportions of patients with acute tubular injury and moderate to severe chronic injuries than the IMN group (all P<0.05). In the IMN, IMN with GTL, and IMN with non-GTL FSGS groups, the overall one-year remission rates were 81.6%, 76%, and 58.8%, respectively. Furthermore, the IMN with non-GTL FSGS group showed the lowest cumulative incidence to reach remission within one year. Multivariate Cox logistic analysis demonstrated that higher level of serum anti-M-type phospholipase A2 receptor antibody and the existence of non-GTL FSGS lesion were independent predictors for no remission in IMN patients.

Conclusion

The non-GTL FSGS lesion was a novel negative predictor in IMN and should be taken into account in the management of IMN.

Early, Noninvasive Clinical Indicators of Kidney Prognosis in Primary Nephrotic Syndrome: A Retrospective Exploratory Study

This retrospective exploratory study aimed to identify early clinical indicators of kidney prognosis in primary nephrotic syndrome (NS). Univariate Cox proportional hazards regression analysis identified clinical parameters in the 2-month period after initiating immunosuppressive therapy (IST); it predicted 40% reduction in the estimated glomerular filtration rate (eGFR) in 36 patients with primary NS. Time-dependent receiver operating characteristic curve analysis was used to evaluate the performance of the predictors for the cumulative incidence of 40% reduction in the eGFR up to 8 years after initiating IST. The mean follow-up period was 71.9 months. The eGFR was reduced by 40% in four patients. Significant predictors for time to 40% reduction in the eGFR were as follows: an increase in the serum soluble urokinase plasminogen activator receptor (s-suPAR) 2 months after initiating IST (Δs-suPAR (2M); hazard ratio (HR) for every 500 pg/mL increase: 1.36, P=0.006), s-suPAR at 2 months after initiating IST (s-suPAR (2M); HR for every 500 pg/mL increase: 1.13, P=0.015), urinary protein-to-creatinine ratio (u-PCR) (u-PCR (2M); HR for every 1.0 g/gCr increase: 2.94, P=0.003), and urinary liver-type fatty acid-binding protein (u-L-FABP) (u-L-FABP (2M); HR for every 1.0 μg/gCr increase: 1.14, P=0.006). All four factors exhibited high predictive accuracy for cumulative incidence of 40% reduction in the eGFR up to 8 years after initiating IST, with areas under the receiver operating characteristic curve of 0.92 for Δs-suPAR (2M), 0.87 for s-suPAR (2M), 0.93 for u-PCR (2M), and 0.93 for u-L-FABP (2M). These findings suggest that Δs-suPAR (2M), s-suPAR (2M), u-PCR (2M), and u-L-FABP (2M) could be useful indicators of initial therapeutic response for predicting kidney prognosis in primary NS.

ANCA-Negative Vasculitis in Eosinophilic Granulomatosis with Polyangiitis Complicated with Membranous Nephropathy: A Case Report and Brief Literature Review

Renal involvement in eosinophilic granulomatosis with polyangiitis (EGPA) typically occurs in anti-neutrophil cytoplasmic autoantibody (ANCA)-positive cases presenting with rapidly progressive renal insufficiency and urinary abnormalities induced by primarily necrotizing crescentic glomerulonephritis (NCGN). Recently, ANCA-negative EGPA has also been reported to manifest with renal involvement, such as NCGN or non-NCGN, including membranous nephropathy (MN). Herein, we report a 70-year-old female who presented with purpura on the lower legs, upper limb numbness, renal dysfunction (eGFR, 20.5 ml/min/1.73 m2), and eosinophilia (eosinophils, 37,570/μl). MPO-and PR3-ANCA were negative, and urinalysis revealed urine protein (0.63 g/day) but without red blood cells in the urine sediment. Thus, she was diagnosed with ANCA-negative EGPA with rapidly progressive renal dysfunction. A renal biopsy revealed vasculitis in the interlobular arteries without NCGN, with the vasculitis being complicated by MN. Micrograph findings on fluorescence immunostaining contained both primary and secondary characteristics of MN (dominance of IgG subclass 4 more than subclass 1 vs. negativity of PLA2R and THSD7A). After treatment with prednisolone, her eosinophil counts normalized, and renal dysfunction improved. Furthermore, urine protein did not increase above 1.0 g/day during the clinical course. This is a rare case of ANCA-negative EGPA presenting with acute renal dysfunction without NCGN and subclinical MN with unknown etiology. It is important to recognize that EGPA pathology varies widely throughout the disease course, and the clinical course of subclinical MN should be carefully assessed in further follow-ups.

Advances in the Management of Primary Membranous Nephropathy and Rituximab-Refractory Membranous Nephropathy

Primary membranous nephropathy (pMN) is an auto-immune disease characterized by auto-antibodies targeting podocyte antigens resulting in activation of complement and damage to the glomerular basement membrane. pMN is the most common cause of nephrotic syndrome in adults without diabetes. Despite a very heterogeneous course of the disease, the treatment of pMN has for many years been based on uniform management of all patients regardless of the severity of the disease. The identification of prognostic markers has radically changed the vision of pMN and allowed KDIGO guidelines to evolve in 2021 towards a more personalized management based on the assessment of the risk of progressive loss of kidney function. The recognition of pMN as an antibody-mediated autoimmune disease has rationalized the use immunosuppressive drugs such as rituximab. Rituximab is now a first line immunosuppressive therapy for patients with pMN with proven safety and efficacy achieving remission in 60-80% of patients. For the remaining 20-40% of patients, several mechanisms may explain rituximab resistance: (i) decreased rituximab bioavailability; (ii) immunization against rituximab; and (iii) chronic glomerular damage. The treatment of patients with rituximab-refractory pMN remains controversial and challenging. In this review, we provide an overview of recent advances in the management of pMN (according to the KDIGO 2021 guidelines), in the understanding of the pathophysiology of rituximab resistance, and in the management of rituximab-refractory pMN. We propose a treatment decision aid based on immunomonitoring to identify failures related to underdosing or immunization against rituximab to overcome treatment resistance.

Revisiting immunological and clinical aspects of membranous nephropathy

Idiopathic or primary membranous nephropathy (IMN) is one of the most frequent causes of nephrotic syndrome in adults and the elderly. It is characterized by a thickening of the wall of the glomerular capillaries due to the presence of immune complex deposits. 85% of membranous nephropathy cases are classified as primary or idiopathic (IMN). The rest are of secondary origin (SMN), caused by autoimmune conditions or malignant tumors as lung cancer, colon and melanomas. It is an organ-specific autoimmune disease in which the complement system plays an important role with the formation of the membrane attack complex (MAC; C5b-9), which produces an alteration of the podocyte structure. The antigen responsible for 70-80% of IMN is a podocyte protein called M-type phospholipase A2 receptor (PLA2R). More recently, another podocyte antigen has been identified, the "Thrombospondin type-1 domain-containing 7A" (THSD7A), which is responsible for 10% of the cases of negative IMN for anti- PLA2R.

A Case of M-Type Phospholipase A2 Receptor-Associated Membranous Nephropathy With IgG4-Positive Cells Infiltration in the Interstitium

A 70-year-old man was referred to our department for evaluation of nephrotic syndrome. Renal biopsy revealed membranous nephropathy (MN). Immunohistochemical analysis demonstrated IgG4-positive staining in the glomeruli and interstitial cells. The presence of serum anti-phospholipase A2 receptor (PLA2R) antibody and enhanced staining of PLA2R in the glomeruli was noted. Computed tomography unidentified the extrarenal lesions of IgG4-related disease. He was diagnosed with PLA2R-associated MN possibly complicated with IgG4 related kidney disease (IgG4-RKD). Storiform fibrosis, a typical manifestation of IgG4-RKD, was not apparent. We herein describe a case of serologically and histologically confirmed PLA2R-associated MN with IgG4+ cell infiltration into the interstitium without any signs of IgG4-RD.

Prevalence of neural epidermal growth factor-like 1- and exostosin 1/exostosin 2-associated membranous nephropathy: a single-center retrospective study in Japan

Membranous nephropathy (MN) is the leading cause of nephrotic syndrome in adults. We previously reported that the prevalence of phospholipase A2 receptor (PLA2R)- and thrombospondin type 1 domain containing 7A (THSD7A)-associated MN patients in Japan is 52.7% and 9.1%, respectively. In addition to PLA2R and THSD7A, we assessed the presence of newly discovered target antigens, neural epidermal growth factor-like 1 (NELL-1), semaphorin 3B (SEMA3B), and exostosin 1/exostosin 2 (Ext1/Ext2), in renal specimens from patients with primary and secondary MN by immunohistochemistry. We found enhanced glomerular staining of PLA2R, THSD7A, NELL-1, and Ext1/Ext2 in 53.6%, 8.7%, 1.5%, and 13.0% of the renal samples, respectively, in patients with primary MN. None of the patient specimens showed enhanced staining of SEMA3B. Enhanced glomerular staining of PLA2R, NELL-1, and Ext1/Ext2 was detected in 5.7%, 8.6%, and 22.9% of the patients with secondary MN, respectively. Based on our findings, we recommend the assessment of PLA2R, THSD7A and NELL-1 in addition to clinical information and IgG4 staining to differentiate between primary and secondary MN. This would aid in distinguishing secondary MN patients from primary MN patients who coincidentally have some secondary characteristics.

Tacrolimus versus cyclophosphamide for patients with idiopathic membranous nephropathy and treated with steroids: a systematic review and meta-analysis of randomized controlled trials

Background

The therapeutic effects of tacrolimus (TAC) versus cyclophosphamide (CTX) were not fully illustrated for patients with idiopathic membranous nephropathy (IMN).

Methods

The PubMed, EmBase, Cochrane library, and CNKI were systematically searched throughout March 2020 for randomized controlled trials evaluating the therapeutic effects of TAC versus CTX for IMN patients treated with steroids. The pooled relative risks (RRs) and weighted mean differences (WMDs) with 95% confidence intervals (CIs) were calculated using the random-effects model.

Results

Twelve trials recruited a total of 868 IMN patients were identified and contained in final meta-analysis. Patients in TAC group was associated with an increased incidence of overall remission (12 trials: 868 patients; RR: 1.21; 95% CI: 1.11–1.31; p < 0.001) and complete remission (12 trials: 868 patients; RR: 1.50; 95% CI: 1.25–1.80; p < 0.001). Moreover, we noted TAC therapy significantly reduced urinary protein excretion (9 trials: 567 patients; WMD: −1.06; 95%CI: −1.41 to −0.71; p < 0.001), and increased serum albumin (9 trials: 567 patients; WMD: 5.37; 95%CI: 2.97 to 7.77; p < 0.001) than CTX therapy. Furthermore, no significant difference between TAC and CTX for serum creatinine was detected (6 trials: 378 patients; WMD: 0.15; 95%CI: −3.46 to 3.75; p = 0.936). Finally, the risk of alopecia (p = 0.008), infection (p = 0.045), leukocytosis (p = 0.002), and elevated ALT/AST (p = 0.011) in TAC group was significantly lower than CTX group, whereas TAC was associated with an increased risk of tremor than CTX (p = 0.010).

Conclusions

This study found IMN patients treated with TAC combined with steroids provides a better therapeutic effect and less adverse events than those treated with CTX combined with steroids, with moderate-certainty evidence.

Herbal Medicine "Shulifenxiao" Formula for Nephrotic Syndrome of Refractory Idiopathic Membranous Nephropathy

Background: Treatment for adult patients with refractory idiopathic membranous nephropathy (RIMN) by conventional immunosuppressive regimens is not satisfactory. This study aims to evaluate the effectiveness of Chinese herbal medicine, Shulifenxiao formula, as a promising regimen.

Methods: A total of 31 RIMN patients resistant to corticosteroid or immunosuppressive agents were retrospectively analyzed. Shulifenxiao treatment lasted a minimum of 12°months in all patients and extended to 24°months in 11 patients. The primary outcomes [the complete remission (CR) and partial remission (PR)] and secondary outcomes (the serum creatinine and estimated glomerular filtration rate (eGFR) levels) were measured at 6, 12, 18, and 24°months.

Results: The data provided an average follow-up of 21 ± 9.16°months from baseline. The remission was attained in 25/31 patients (80.7%: CR 29.0% and PR 51.6%) at 12°months and in 10/11 patients (90.9%: CR 54.6% and PR 36.4%) at 24°months, respectively. Proteinuria reduced from 6.02 g/d at baseline to 0.98 g/d at 12°months (p < 0.001) and to 0.27 g/d at 24°months (p = 0.003); serum albumin increased from 28 g/L to 37.2 g/L at 12°months (p < 0.001) and to 41.3 g/L at 24°months (p = 0.003); eGFR improved from 100.25 ml/min/1.73 m² to 118.39 ml/min/1.73 m² at 6°months (p < 0.001) and finally to 111.62 ml/min/1.73 m²at 24°months (p = 0.008). Only two patients developed subsequent relapse.

Conclusion: Shulifenxiao formula as a clinical cocktail therapy serves as an alternative therapeutic option for steroid and immunosuppressant-resistant RIMN patients, with a favourable safety profile, though further studies are warranted.

Clinical Trial registration:http://www.chictr.org.cn, Chinese Clinical Trials Registry [ChiCTR1800019351].

Diffusion kurtosis imaging for the assessment of renal fibrosis of chronic kidney disease: A preliminary study

PURPOSE

To investigate the potential of diffusion kurtosis imaging (DKI) for the assessment of renal fibrosis in chronic kidney disease (CKD), using histopathology as the reference standard.

METHODS

Eighty-nine CKD patients and twenty healthy volunteers were recruited in this study. DKI was performed in all participants and all CKD patients received renal biopsy. The values of mean diffusivity (MD) and mean kurtosis (MK) in the renal cortex and medulla were compared between CKD patients and healthy volunteers. The Spearman correlation coefficient was calculated to assess the relationship between MD, MK values and the estimated glomerular filtration rate (eGFR), serum creatinine (SCr), 24 h urinary protein (24 h-UPRO), histopathological fibrosis score.

RESULTS

The medullary MD values were significantly lower than cortex, while the cortical MK values were significantly lower than medulla for all participants. Renal parenchymal MD values were significantly lower in the CKD patients than healthy controls, whereas MK values were significantly higher in the CKD patients than healthy controls. In the CKD patients, the significantly negative correlation was observed between the renal parenchymal MD values and the 24 h-UPRO, SCr, histopathological fibrosis score, as well as between the renal parenchymal MK values and the eGFR, while the significantly positive correlation was found between the renal parenchymal MD values and the eGFR, as well as between the renal parenchymal MK values and the 24 h-UPRO, SCr, histopathological fibrosis score.

CONCLUSION

DKI shows great potential in the noninvasive assessment of renal fibrosis in CKD.

Electron-Dense Deposition Patterns and the Outcomes of Nephrotic Idiopathic Membranous Nephropathy Treated with Tacrolimus in Chinese Adults

Background

Tacrolimus may be effective in the short-term treatment of idiopathic membranous nephropathy (IMN). However, it is not clear whether an electron microscopic classification of the homogeneous and heterogeneous types of nephrotic IMN is related to the efficacy of tacrolimus in patients with IMN. This study aimed to explore this question and to provide evidence for individualized patient treatment.

Material/Methods

This 6-month retrospective study included 61 Chinese patients previously diagnosed with IMN. Patients received treatment was tacrolimus plus glucocorticoid. The patients were divided into a homogeneous group and a heterogeneous group based on the evaluation of electron-dense deposits. The initial clinicopathologic factors in the 2 groups were analyzed, and the difference in efficacy of tacrolimus in the 2 groups was assessed. The factors predicting remission were also studied.

Results

No significant alteration in the initial clinicopathologic status was found between the 2 groups, except for proteinuria, serum albumin levels, systolic blood pressure, and renal biopsy results (stages I/II/III/IV). After 3 months of treatment, the difference in remission was not significant between the 2 groups. However, after 6 months of treatment, a significant difference in remission rates was observed between the 2 groups. The binary logistic model showed that the homogeneous nephrotic IMN was independently associated with total remission (partial plus complete remission), and was also related to complete remission.

Conclusions

The results of our study revealed that the homogeneous type of nephrotic IMN had a higher short-term remission rate and a predictive value for partial or complete remission, and it might be a meaningful marker of the short-term response to tacrolimus.

Clinicopathologic characteristic and prognosis in idiopathic membranous nephropathy patients with focal segmental sclerosis lesion: A retrospective observational study

To explore the clinicopathological characteristics and prognosis of idiopathic membranous nephropathy (IMN) with focal segmental sclerosis lesions (FSL). A total of 70 IMN patients with FSL (FSL+group) were enrolled in this study, and 140 patients were randomly selected by age and sex matching as disease controls (FSL-group). The clinical and renal histopathological data on renal biopsy and clinical data of patients regularly followed were collected. Serum anti-phospholipase A2 receptor (PLA2R) autoantibody, thrombospondin type-1 domain-containing 7A (7A) autoantibody, glomerular PLA2R and 7A expression, and IgG4 deposition were detected. First, the clinical and pathological significance of IMN combined with the FSL group was analyzed. Whether FSL is a risk factor for renal outcomes was further analyzed. 1. Compared with the FSL- group, patients in the FSL+ group had a significantly higher incidence of hypertension and a longer duration of hypertension as well as higher levels of systolic blood pressure, serum creatinine, serum triglycerides, serum cholesterol, 24-hour urinary protein excretion, and lower eGFR and urine osmotic pressure. Patients in the FSL+ group had an increased frequency of Churg stage III and more severe glomerulosclerosis and interstitial fibrosis. The remission rate was significantly lower in the FSL+ group than in the FSL- group (50.0% vs 75.9%, P = .027). 2. Multivariate Cox regression analysis showed that FSL (HR = 3.01, 95%CI = 1.07–8.52, P = .038) was an independent risk factor for progression of renal function deterioration, and FSL (HR = 3.25, 95%CI = 1.43–7.38, P = .005) and high levels of serum anti-PLA2R antibody (HR = 1.89, 95%CI = 1.27–2.82, P = .002) were independent risk factors for nonremission of IMN. IMN patients who developed FSL had more severe clinical and pathological characteristics than those without FSL. FSL was an independent risk factor for poorer prognosis. When the appearance of FSL in IMN patients with a high level of serum anti-PLA2R antibody, the treatment needs to be more aggressive to promote remission and to delay the progression of renal function.

Idiopathic membranous nephropathy in older patients: Clinical features and outcomes

Background

Various factors can affect renal and patient outcome in idiopathic membranous nephropathy (iMN). We aimed to identify predictors of renal and patient survival in patients with iMN, with a special focus on outcomes among older patients.

Methods

We retrieved data on 1,776 patients (mean age 53.0 ± 14.7 years; 1,075 [60.5%] males) diagnosed with iMN from the Korean GlomeruloNEphritis sTudy (KoGNET), a database compiled from 18 centers in Korea.

Results

The cohort included 428 (24.1%) patients over 65 years old. Compared to younger patients, this group had lower hemoglobin and serum albumin levels, a higher incidence of nephrotic-range proteinuria, and higher prevalences of hypertension and diabetes. At last follow-up, complete or partial remission rates were not significantly different between the older and younger groups. Older age (HR: 0.98, 95%CI: 0.97–0.99), elevated hemoglobin (HR: 0.82, 95%CI: 0.72–0.93), high serum albumin (HR: 0.66, 95%CI: 0.44–0.99), and a high estimated glomerular filtration rate (HR: 0.96, 95%CI: 0.95–0.97) at biopsy were good predictors of renal outcomes. Significant risk factors for patient survival were older age (HR: 1.04, 95%CI: 1.01–1.10) and hypertension at biopsy (HR: 2.76, 95%CI: 1.30–5.90).

Conclusions

Older patients with iMN had favorable renal outcomes, but poor patient survival, compared to younger patients. Prognostic information on outcomes in this study might be helpful for optimizing the management of patients with iMN.

Glomerulosclerosis predicts poor renal outcome in patients with idiopathic membranous nephropathy

OBJECTIVE

This study aimed to investigate the association between the proportion of glomerulosclerosis (focal segmental glomerulosclerosis and/or global glomerulosclerosis) and renal prognosis in patients with idiopathic membranous nephropathy (IMN).

METHODS

A retrospective analysis performed from January 2008 to December 2017 in the First Affiliated Hospital of Shenzhen University by renal biopsy confirmed 200 patients with IMN, and their clinical pathology and prognosis were compared. Patients were divided into three groups on the basis of glomerular sclerosis proportion tertiles: low (Tertile1 group, proportion of glomerulosclerosis, 0-0%), middle (Tertile2 group, proportion of glomerulosclerosis, 0-5.5%) and high (Tertile3 group, proportion of glomerulosclerosis, 5.8-72.7%) tertiles. The follow-up endpoints were decreased estimated glomerular filtration rate (eGFR) by 20%, end-stage renal disease, and all-cause mortality.

RESULTS

(1) Both, the Tertile1 and Tertile2, groups had significantly lower albumin level and higher 24-h urine protein level than that in the Tertile3 group. Regarding treatment, as the proportion of glomerulosclerosis increases, a more aggressive treatment with glucocorticoids and immunosuppressants should be provided. (2) Correlation analysis showed that the proportion of glomerulosclerosis was positively associated with age (P < 0.05). However, it was negatively associated with eGFR (P < 0.05). (3) Renal tubular atrophy and renal interstitial inflammatory cell infiltration were considered independent correlative factors for glomerulosclerosis. Kaplan-Meier analysis revealed that renal survival rate was significantly lower in patients with a proportion of glomerulosclerosis ≥ 6.45% than in patients with a proportion of glomerulosclerosis < 6.45%. Cox regression analysis revealed that as the proportion of glomerulosclerosis increases, the risk of renal outcomes increases gradually.

CONCLUSIONS

Patients in the Tertile3 (higher proportion of glomerulosclerosis) group had more severe renal pathological damage compared to patients in the Tertile1 and Tertile2 groups. Glomerulosclerosis is a risk factor for renal function progression and poor renal prognosis in patients with IMN. As the proportion of glomerulosclerosis increases, the risk of renal endpoint events increases gradually.

A nomogram for the prediction of renal outcomes among patients with idiopathic membranous nephropathy

The early prediction of renal outcomes in patients with idiopathic membranous nephropathy (iMN) remains challenging. The present retrospective study evaluated patients with iMN confirmed by renal biopsy. An optimized Cox regression model and a nomogram were constructed for the early prediction of renal outcomes. A total of 141 patients who met the inclusion criteria were evaluated in the present study. In total 18 (12.8%) patients eventually progressed to the endpoint, 6 of whom developed end-stage renal disease, and one patient died during follow-up. The optimized model demonstrated that 24-h proteinuria [hazard ratio (HR) 1.24; 95% CI, 1.10-1.40; P-value <0.001] and chronic tubulointerstitial injury [referred to as grade 0, grade 1 (HR), 5.12; 95% CI, 1.33-19.75; P-value=0.02] or grade 2 (HR, 6.43; 95% CI, 1.35-30.59; P-value=0.02) were independent risk factors for a poor renal outcome. Patients with an estimated three-year renal survival rate (ETR) less than 0.87 had a high risk of a poor renal outcome. In addition, patients with an ETR of 0.87 to 0.98 more quickly developed a decreased estimated glomerular filtration rate after two years of follow-up. In the present study a nomogram for the early prediction of renal outcomes in patients with iMN was developed. This nonogram suggested that patients with an ETR of 0.87-0.98 should receive greater attention during follow-up.

Better remission rates in elderly Japanese patients with primary membranous nephropathy in nationwide real-world practice: The Japan Nephrotic Syndrome Cohort Study (JNSCS)

BACKGROUND

The aim of the present study was to clarify the prevalence of immunosuppressive drug use and outcomes in elderly and non-elderly patients with primary membranous nephropathy (MN) in nationwide real-world practice in Japan.

PATIENTS AND METHODS

Between 2009 and 2010, 374 patients with primary nephrotic syndrome were enrolled in the cohort study (The Japan Nephrotic Syndrome Cohort Study, JNSCS), including 126 adult patients with MN. Their clinical characteristics were compared with those of nephrotic patients with primary MN registered in a large nationwide registry (The Japan Renal Biopsy Registry, J-RBR). Outcomes and predictors in the elderly (≥ 65 years) and non-elderly groups were identified.

RESULTS

Similar clinical characteristics were observed in JNSCS patients and J-RBR patients (n = 1808). At the early stage of 1 month, 84.1% of patients were treated with immunosuppressive therapies. No significant differences were observed in therapies between age groups. However, elderly patients achieved complete remission (CR) more frequently than non-elderly patients, particularly those treated with therapies that included corticosteroids. No significant differences were noted in serum creatinine (sCr) elevations at 50 or 100%, end-stage kidney disease, or all-cause mortality between age groups. Corticosteroids were identified as an independent predictor of CR (HR 2.749, 95%CI 1.593-4.745, p = 0.000) in the multivariate Cox's model. sCr levels, hemoglobin levels, immunosuppressants, clinical remission, and relapse after CR were independent predictors of sCr × 1.5 or × 2.0.

CONCLUSION

Early immunosuppressive therapy including corticosteroids for primary MN showed better remission rates in elderly patients in a nationwide cohort study.

The Landscape and Prognosis Potential of the T-Cell Repertoire in Membranous Nephropathy

Membranous nephropathy (MN), a common pathological type of adult nephrotic syndrome, is an antibody-mediated kidney disease. It is widely accepted now that MN is an immune-related disease that involves the whole immune system. In this study, we analyzed the T-cell receptor beta chain (TCRβ) repertoire of the circulating T lymphocytes of MN patients and healthy controls using high-throughput sequencing. We compared multiple aspects of the TCRβ repertoire, including diversity and the Vβ and Jβ genes between MN patients and healthy controls, and we found that the diversities within the VJ cassette combination in the peripheral blood of MN patients were lower than in the healthy controls. We also found the TCRβ repertoire similarity between pre- and post-therapy could reflect the clinical outcome, and two Vβ genes in pre-therapy had the potential to predict the therapeutic effect. These findings indicated the potential of the TCRβ repertoire as non-invasive biomarkers for the prognosis prediction of MN. The characteristics of circulating T-lymphocyte repertoires shed light on MN detection, treatment, and surveillance.

Incidence of remission and relapse of proteinuria, end-stage kidney disease, mortality, and major outcomes in primary nephrotic syndrome: the Japan Nephrotic Syndrome Cohort Study (JNSCS)

Background

Despite recent advances in immunosuppressive therapy for patients with primary nephrotic syndrome, its effectiveness and safety have not been fully studied in recent nationwide real-world clinical data in Japan.

Methods

A 5-year cohort study, the Japan Nephrotic Syndrome Cohort Study, enrolled 374 patients with primary nephrotic syndrome in 55 hospitals in Japan, including 155, 148, 38, and 33 patients with minimal change disease (MCD), membranous nephropathy (MN), focal segmental glomerulosclerosis (FSGS), and other glomerulonephritides, respectively. The incidence rates of remission and relapse of proteinuria, 50% and 100% increases in serum creatinine, end-stage kidney disease (ESKD), all-cause mortality, and other major adverse outcomes were compared among glomerulonephritides using the Log-rank test. Incidence of hospitalization for infection, the most common cause of mortality, was compared using a multivariable-adjusted Cox proportional hazard model.

Results

Immunosuppressive therapy was administered in 339 (90.6%) patients. The cumulative probabilities of complete remission within 3 years of the baseline visit was ≥ 0.75 in patients with MCD, MN, and FSGS (0.95, 0.77, and 0.79, respectively). Diabetes was the most common adverse events associated with immunosuppressive therapy (incidence rate, 71.0 per 1000 person-years). All-cause mortality (15.6 per 1000 person-years), mainly infection-related mortality (47.8%), was more common than ESKD (8.9 per 1000 person-years), especially in patients with MCD and MN. MCD was significantly associated with hospitalization for infection than MN.

Conclusions

Patients with MCD and MN had a higher mortality, especially infection-related mortality, than ESKD. Nephrologists should pay more attention to infections in patients with primary nephrotic syndrome.

Electronic supplementary material

The online version of this article (10.1007/s10157-020-01864-1) contains supplementary material, which is available to authorized users.

Retrospective study: clinicopathological features and prognosis of idiopathic membranous nephropathy with seronegative anti-phospholipase A2 receptor antibody

Background

To discuss the clinicopathological features and prognosis of patients with idiopathic membranous nephropathy (IMN) who are serum-negative for the anti-PLA2R antibody.

Method

Overall, 229 IMN patients were retrospectively collected in this study and classified into anti-PLA2R antibody-negative (PLA2R−, 59 cases) and antibody-positive (PLA2R+, 170 cases) groups. The clinical and pathological features of the PLA2R− group were analyzed; 162 patients in both groups were followed up, and the PLA2R antigen was detected in renal biopsies from the PLA2R− group. Kaplan-Meier and survival analyses were used to compare differences in prognosis.

Results

Serum albumin levels were higher and 24-hour urine protein, creatinine, and beta 2-microglobulin (BMG) levels were lower in the PLA2R− group than in the PLA2R+ group; the proportion of acute and chronic tubular lesions was also significantly lower in the PLA2R− group than in in the PLA2R+ group. After treatment, the remission rate was significantly higher in the negative group than in the positive group (93.02% vs 74.78%,), especially the rate of complete remission (51.16% vs 23.47%). Furthermore, the PLA2R antigen-positive staining rate of 43 patients in the PLA2R− group was 62.79%. Although not significant, the survival rate was higher in the PLA2R− group than in the PLA2R+ group. BMG, 24-hour urine protein and acute and chronic tubular lesions were risk factors for kidney death, and 24-hour urine protein was an independent risk factor for kidney death.

Conclusions

Compared with the PLA2R+ group, the PLA2R− group had mild clinical manifestations and pathological damage and a higher clinical treatment remission rate. Renal tissue PLA2R antigen testing can be considered for patients with seronegative IMN to increase the diagnostic rate.

Clinical and pathological features of idiopathic membranous nephropathy with focal segmental sclerosis

Background

The goal of this study was to investigate the clinical and pathological features and prognosis of idiopathic membranous nephropathy (IMN) with focal segmental lesions.

Methods

In our hospital, 305 patients with nephrotic syndrome confirmed as IMN by renal biopsy were divided into a non-focal segmental lesion group (FSGS- group) and a focal segmental glomerulosclerosis (FSGS) group (FSGS+ group) and retrospectively analyzed. In all, 180 patients were followed for periods ranging from 6 months to 2 years. The general clinicopathological data of both groups were compared, and the effects of different treatment schemes on the prognosis of both groups were observed.

Results

The FSGS+ group had a longer disease course, higher blood pressure levels, and higher serum creatinine and β₂-microglobulin levels than did the FSGS- group (all P < 0.05). Pathologically, the FSGS+ group had increased glomerular sclerosis, glomerular mesangial hyperplasia, and acute and chronic tubular lesion rates (all P < 0.05). The remission rate was lower in the FSGS+ group than in the FSGS- group (64.7% vs 82.2%) and, among patients in the FSGS+ group, was lower in patients treated with calmodulin inhibitors than in those treated with cyclophosphamide (P < 0.01). Survival analysis showed that the FSGS+ group had a poor prognosis (χ² = 4.377, P = 0.036), and risk factor analysis suggested that age at renal biopsy (P = 0.006), 24-h urinary protein quantity (P = 0.01), chronic tubulointerstitial lesions (P = 0.055), and FSGS lesions (P = 0.062) were risk factors for worsening renal condition; furthermore, 24-h urinary protein quantity was an independent risk factor for worsening renal condition.

Conclusions

Membranous nephropathy with FSGS is a risk factor, but not an independent risk factor, for IMN. Patients with membranous nephropathy with FSGS often present hypertension and tubule injury. The nonselective drug cyclophosphamide is preferred, and calcineurin inhibitors should be used with caution.

Baseline proteinuria level is associated with prognosis in idiopathic membranous nephropathy

Objectives: This study aimed to investigate the unique prognostic, clinical, and renal histopathological characteristics of patients with idiopathic membranous nephropathy (IMN) with different levels of proteinuria.

Methods: This retrospective observational study included 190 IMN patients with low levels of proteinuria (low group), 193 IMN patients with medium levels of proteinuria (medium group), and 123 IMN patients with high levels of proteinuria (high group) treated between September 2006 and November 2015. Prognostic and baseline clinical and histopathological data were compared among the three groups. Poor prognostic events included the occurrence of a persistent 50% reduction in estimated glomerular filtration rate (eGFR), end-stage renal disease, or all-cause mortality.

Results: The severity of clinical symptoms and laboratory indices, such as blood pressure; extent of edema and hematuria; levels of fibrinogen, immunoglobulin (Ig)-G, complement (C)-4, total protein, albumin (ALB), and serum creatinine (SCr); and eGFR increased with increasing proteinuria (all p< .001). Based on renal histopathology, the extent of segmental sclerosis and balloon adhesion and renal interstitial lesion stage also increased in severity with increasing proteinuria (all p< .001). The Kaplan–Meier analysis showed that compared with patients with low and medium levels of proteinuria, patients with high levels of proteinuria had significantly lower cumulative poor event-free renal survival rates (p= .0039).

Conclusions: Baseline proteinuria level is indicative of prognosis in IMN patients; the greater the extent of proteinuria is, the worse the prognosis.

Clinical outcomes and effects of treatment in older patients with idiopathic membranous nephropathy

BACKGROUND/AIMS

Membranous nephropathy (MN) is the most common primary glomerular disease diagnosed in older patients. Few reports describe the clinical outcomes in older patients with idiopathic MN.

METHODS

The outcomes of 135 patients with histologically proven MN were analyzed. 'Older' was defined as 60 years of age or older at the time of the renal biopsy. The rates of complete remission (CR), progression to end-stage renal disease (ESRD) and infection were compared between older and younger patients.

RESULTS

The cumulative event rate for achieving CR was inferior (p = 0.012) and that for requiring renal replacement was higher (p = 0.015) in older patients, and they had a greater risk of infection (p = 0.005). Older age was a significant predictor of a lower rate of CR (adjusted odds ratio [OR], 0.51; 95% confidence interval [CI], 0.26 to 0.98), and was a robust predictor of infection (adjusted OR, 5.27; 95% CI, 1.31 to 21.20). Conservative treatment was associated with a lower remission rate (p = 0.036) and corticosteroid treatment was less effective in achieving CR (p = 0.014), in preventing progression to ESRD (p = 0.013) and in reducing infection (p = 0.033) in older patients. Cyclosporine treatment had similar clinical outcomes with regard to CR, ESRD progression, and infection in older patients.

CONCLUSION

Older age was independently associated with inferior rates of CR and greater risk of infection. Treatment modalities affected the outcomes of older patients differently in that cyclosporine treatment is predicted to be more useful than corticosteroids.