Negative anti-phospholipase A2 receptor antibody status at three months predicts remission in primary membranous nephropathy

Comparing Long-Term Outcomes in Glomerular Disease Patients Presenting with Nephrotic Syndrome Versus Nephrotic Range Proteinuria

BACKGROUND

Despite extensive research on proteinuria's impact on chronic kidney disease progression, there is no direct comparison of outcomes in biopsy-diagnosed glomerular disease (GD) patients with nephrotic syndrome (NS) or nephrotic range proteinuria (NRP). Our study addresses this gap, comparing long-term outcomes between NS and NRP.

METHODS

We conducted a retrospective study on 240 kidney biopsy-proven GD patients, tracked from 2010 to 2015 until end-stage kidney disease (ESKD), death, or the study end in January 2022.

RESULTS

The median follow-up was 8.8 years. Diagnoses were predominantly nonproliferative (53%), proliferative (25%) nephropathies, diabetic nephropathy (12%), and paraprotein diseases (10%). NS was observed in 141 (59%) patients, presenting more frequently with arterial hypertension, higher eGFR, increased proteinuria, and dyslipidemia than NRP patients. NRP patients often had proliferative GD and diabetic nephropathy; their renal chronicity score was higher. The ESKD endpoint occurred in 35% NS and 39% NRP patients (p 0.4). The cohort's mean kidney survival time was 8.2 years. In a multivariate analysis, NS, lower eGFR, a higher renal chronicity score, and diabetic nephropathy were associated with ESKD. A total of 64 patients (27%) died, 73% post-kidney replacement therapy initiation, and mostly from cardiovascular disease (63%). Mortality between proteinuria forms showed no difference. The multivariate analysis found lower eGFR, a higher Charlson comorbidity score, and diabetic nephropathy associated with mortality.

CONCLUSIONS

Our study found no difference in all-cause mortality between NS and NRP in glomerular diseases. However, an adjusted analysis revealed poorer kidney survival for NS patients, emphasizing the need for personalized management to improve renal prognoses.

Prediction model for treatment response of primary membranous nephropathy with nephrotic syndrome

OBJECTIVE

To investigate the predictors and establish a nomogram model for the prediction of the response to treatment in primary membranous nephropathy (PMN) with nephrotic syndrome (NS).

METHODS

The clinical, laboratory, pathological and follow-up data of patients with biopsy-proven membranous nephropathy at the Affiliated Hospital of Qingdao University were collected. A total of 373 patients were randomly assigned into development group (n = 262) and validation group (n = 111). Logistic regression analysis was performed in the development group to determine the predictors of treatment response. A nomogram model was established based on the multivariate logistic regression analysis and validated in the validation group. The C-index and calibration plots were used for the evaluation of the discrimination and calibration performance, respectively.

RESULTS

Serum albumin levels (OR = 1.151, 95% CI 1.078-1.229, P < 0.001) and glomerular C3 deposition (OR = 0.407, 95% CI 0.213-0.775, P = 0.004) were identified as independent predictive factors for treatment response in PMN with NS, then a nomogram was established combining the above indicators and treatment regimen. The C-indices of this model were 0.718 (95% CI 0.654-0.782) and 0.789 (95% CI 0.705-0.873) in the development and validation groups, respectively. The calibration plots showed that the predicted probabilities of the model were consistent with the actual probabilities (P > 0.05), which indicated favorable performance of this model in predicting the treatment response probability.

CONCLUSIONS

Serum albumin levels and glomerular C3 deposition were predictors for treatment response of PMN with NS. A novel nomogram model with good discrimination and calibration was constructed to predict treatment response probability at an early stage.

Prognostic Value of Inflammation Scores and Hematological Indices in IgA and Membranous Nephropathies: An Exploratory Study

Background and Objectives: Systemic-inflammation-based prognostic scores and hematological indices have shown value in predicting outcomes in various clinical settings. However, their effectiveness in predicting outcomes specifically for IgA nephropathy (IgAN) and membranous nephropathy (MN), the most common primary glomerular diseases diagnosed by kidney biopsy, has not been thoroughly investigated. Materials and Methods: We conducted a retrospective, observational study involving 334 adult patients with biopsy-proven IgAN (196 patients) and MN (138 patients) from January 2008 to December 2017 at a tertiary center. We assessed six prognostic scores [Glasgow prognostic score (GPS), modified GPS (mGPS), prognostic nutritional index (PNI), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), lymphocyte-to-C-reactive protein ratio (LCRP)] and two hematological indices [red blood cell distribution width (RDW), platelet distribution width (PDW)] at diagnosis and examined their relationship with kidney and patient survival. Results: End-stage kidney disease (ESKD) occurred more frequently in the IgAN group compared to the MN group (37% vs. 12%, p = 0.001). The mean kidney survival time was 10.7 years in the IgAN cohort and 13.8 years in the MN cohort. After adjusting for eGFR and proteinuria, lower NLR and higher LCRP were significant risk factors for ESKD in IgAN. In the MN cohort, no systemic-inflammation-based scores or hematological indices were associated with kidney survival. There were 38 deaths (19%) in the IgAN group and 29 deaths (21%) in the MN group, showing no significant difference in mortality rates. The mean survival time was 13.4 years for the IgAN group and 12.7 years for the MN group. In the IgAN group, a lower PLR was associated with a higher mortality after adjusting for age, the Charlson comorbidity score, eGFR, and proteinuria. In patients with MN, higher NLR, PLR, and RDW were associated with increased mortality. Conclusions: NLR and LCRP are significant predictors of ESKD in IgAN, while PLR is linked to increased mortality. In MN, NLR, PLR, and RDW are predictors of mortality but not kidney survival. These findings underscore the need for disease-specific biomarkers and indicate that systemic inflammatory responses play varying roles in the progression and outcomes of these glomerular diseases. Future studies on larger cohorts are necessary to validate these markers.

Membranous Nephropathy: Updates on Management

Membranous nephropathy is a major etiology of nephrotic syndrome in adults and less frequently in children. Circulating antibodies to intrinsic podocyte antigens, such as M-type phospholipase A2 receptor, or to extrinsic proteins accumulate beneath the podocyte to cause damage via complement activation and/or other mechanisms. The availability of clinical testing for autoantibodies to M-type phospholipase A2 receptor has allowed noninvasive diagnosis of this form of membranous nephropathy and a means to monitor immunologic activity to guide immunosuppressive therapy. Treatment of membranous nephropathy includes optimal supportive care with renin-angiotensin-system blockers, lipid-lowering agents, diuretics, lifestyle changes, and additional immunosuppressive therapy in patients with an increased risk of progression to kidney failure. Rituximab has been recognized as a first-line immunosuppressive therapy for most membranous nephropathy patients with an increased risk of progressive disease, except those with life-threatening nephrotic syndrome or rapidly deteriorating kidney function from membranous nephropathy. This article discusses the major and minor antigens described in membranous nephropathy, the natural history of the disease, and guidelines for clinical management and immunosuppressive treatment.

Comparison of tacrolimus with or without prednisone therapy in primary membranous nephropathy: a retrospective clinical study

Previous studies showed tacrolimus monotherapy and dual therapy with tacrolimus and prednisone as effective treatment modalities in managing membranous nephropathy. However, few studies have compared these therapeutic regimens. The patients were divided into two groups based on the treatment regimen: (1) tacrolimus and prednisone dual therapy (T + P group, n = 67) treatment group; and (2) tacrolimus monotherapy (T group, n = 65) or the control group. Propensity matching method and subgroup analysis to eliminate the bias in the relationship between the treatment regimen and the outcomes. The mean remission times were 20.33 ± 2.75 weeks at T group and 9.50 ± 1.81 weeks at T + P group. The T group had a remission rates of 73.33, 76.66 and 66.66% at 12weeks, 24weeks and 48weeks, while the T + P group had a remission rate of 81.66, 86.66, 91.66%; At the follow-up of 48 weeks, the relapse rate for the T group was 21.66%, and that for the T + P group was 5%. The anti-PLA2R ab is positive and therapy may be the independent risk factors for predicting remission. Tacrolimus and low-dose prednisone dual therapy is efficacious in managing MN and lowers the recurrence rate in clinical practice.

Predictive value of the domain specific PLA2R antibodies for clinical remission in patients with primary membranous nephropathy: A retrospective study

BACKGROUND

M-type phospholipase A2 receptor (PLA2R) is a major auto-antigen of primary membranous nephropathy(PMN). Anti-PLA2R antibody levels are closely associated with disease severity and therapeutic effectiveness. Analysis of PLA2R antigen epitope reactivity may have a greater predictive value for remission compared with total PLA2R-antibody level. This study aims to elucidate the relationship between domain-specific antibody levels and clinical outcomes of PMN.

METHODS

This retrospective analysis included 87 patients with PLA2R-associated PMN. Among them, 40 and 47 were treated with rituximab (RTX) and cyclophosphamide (CTX) regimen, respectively. The quantitative detection of -immunoglobulin G (IgG)/-IgG4 targeting PLA2R and its epitope levels in the serum of patients with PMN were obtained through time-resolved fluorescence immunoassays and served as biomarkers in evaluating the treatment effectiveness. A predictive PMN remission possibility nomogram was developed using multivariate logistic regression analysis. Discrimination in the prediction model was assessed using the area under the receiver operating characteristic curve (AUC-ROC).Bootstrap ROC was used to evaluate the performance of the prediction model.

RESULTS

After a 6-month treatment period, the remission rates of proteinuria, including complete remission and partial remission in the RTX and CTX groups, were 70% and 70.21% (P = 0.983), respectively. However, there was a significant difference in immunological remission in the PLA2R-IgG4 between the RTX and CTX groups (21.43% vs. 61.90%, P = 0.019). Furthermore, we found differences in PLA2R-CysR-IgG4(P = 0.030), PLA2R-CTLD1-IgG4(P = 0.005), PLA2R-CTLD678-IgG4(P = 0.003), and epitope spreading (P = 0.023) between responders and non-responders in the CTX group. Multivariate logistic analysis showed that higher levels of urinary protein (odds ratio [OR], 0.49; 95% confidence interval [CI], 0.26-0.95; P = 0.035) and higher levels of PLA2R-CTLD1-IgG4 (OR, 0.79; 95%CI,0.62-0.99; P = 0.041) were independent risk factors for early remission. A multivariate model for estimating the possibility of early remission in patients with PMN is presented as a nomogram. The AUC-ROC of our model was 0.721 (95%CI, 0.601-0.840), in consistency with the results obtained with internal validation, for which the AUC-ROC was 0.711 (95%CI, 0.587-0.824), thus, demonstrating robustness.

CONCLUSIONS

Cyclophosphamide can induce immunological remission earlier than rituximab at the span of 6 months. The PLA2R-CTLD1-IgG4 has a better predict value than total PLA2R-IgG for remission of proteinuria at the 6th month.

Association of M-Type Phospholipase A2 Receptor Deposition in Kidney Tissue with Treatment Outcomes in Patients with Idiopathic Membranous Nephropathy

Objective

The purpose of this study was to investigate the correlation between the deposition of M-type phospholipase A2 receptor (PLA2R) in the kidney tissues of patients with idiopathic membranous nephropathy (IMN).

Method

We enrolled a total of 61 patients diagnosed with IMN in the past 8 years who were admitted at the Jinjiang Municipal Hospital and the 2nd Affiliated Hospital of Fujian Medical University. PLA2R immunofluorescence was used to stain kidney tissues, and all patients were treated with steroid combined with immunosuppressive agents or conservative regimens. The duration of follow-up was more than 48 weeks. Based on the deposition of PLA2R in kidney tissues, we divided the patients into the PLA2R Positive group and the PLA2R Negative group. Further, patients with PLA2R-positive kidney tissues were divided into "1+", "2+", and "3+" groups based on the extent of their PLA2R deposition, and we compared the therapeutic outcomes of the various groups.

Results

At week 12 of follow-up, the partial remission rate of kidney tissues in the PLA2R Negative group was significantly higher than that in the Positive group (P = 0.004). Among the various deposition groups with PLA2R-positive kidney tissues, the complete remission rate of the "2+" group was higher than that of the "3+" group at weeks 24, 36, and 48 of follow-up (P < 0.05). In IMN patients treated with a combination regimen of steroid and tacrolimus, the complete remission rate in kidney tissues of the PLA2R Negative group was higher than that of the Positive group at weeks 24 and 48 of follow-up (P < 0.05).

Conclusion

The overall effective rate of treatment in kidney tissues of PLA2R-negative patients was higher than that in the kidney tissues of PLA2R-positive patients. The varied levels of PLA2R deposition in kidney tissues were related to the treatment outcomes of IMN, and those with lower PLA2R deposition levels had better outcomes.

The application of podocyte antigen PLA2R and anti-PLA2R antibody in the diagnosis and treatment of membranous nephropathy

BACKGROUND

The application of podocyte antigen M-type phospholipase A2 receptor (PLA2R, GAg) and serum anti-PLA2R antibody (SAb) in predicting the prognosis of membrane nephropathy (MN) was controversial.

METHOD

328 biopsy-proven MN patients were divided into three phenotypes, 182 MN patients with GAg+/SAb+, 118 MN patients with GAg+/SAb-, and 28 MN patients with GAg-/SAb-. The baseline clinicopathological characteristics, therapy response, and prognosis were compared among the three groups. Cox regression analysis was performed to assess predictors of remission. Anti-PLA2R antibody was analyzed by receiver operating characteristic curve to find the optimal titer for MN diagnosis.

RESULT

Lower eGFR (p = 0.009), higher UPCR (p < 0.001), and lower serum albumin (p < 0.001) were observed in GAg+/SAb+ MN patients, compared to GAg+/SAb- MN patients. More GAg+/SAb+ MN patients received cyclophosphamide (CTX) combined with glucocorticoids and calcineurin inhibitors (CNI) based therapy than the other two groups (p = 0.015 and p = 0.023, respectively). No significant difference was observed among the three groups in terms of complete remission, relapse, and developing ESRD. SAb+ status was an independent predictor for no remission (hazard ratio 1.378, 95% confidence interval 1.023 to 1.855; p = 0.035). The optimal cutoff value for anti-PLA2R antibody to predict MN was 2.055 RU/mL (sensibility 0.802, specificity 0.970).

CONCLUSION

GAg+/SAb+ MN patients were related to more severe clinical manifestations and more requisition of immunosuppressive treatment. Positive anti-PLA2R antibody was an independent predictor for no remission. An anti-PLA2R antibody above 2.055 RU/mL can be a suggestive indicator of MN diagnosis in patients with proteinuria.

A nomogram prediction model for treatment failure in primary membranous nephropathy

BACKGROUND

Primary membranous nephropathy (PMN) has a heterogeneous natural course. Immunosuppressive therapy is recommended for PMN patients at moderate or high risk of renal function deterioration. Prediction models for the treatment failure of PMN have rarely been reported.

METHODS

This study retrospectively studied patients diagnosed as PMN by renal biopsy at Sichuan Provincial People's Hospital from January 2017 to December 2020. Information on clinical characteristics, laboratory test results, pathological examination, and treatment was collected. The outcome was treatment failure, defined as the lack of complete or partial remission at the end of 12 months. Simple logistic regression was used to identify candidate predictive variables. Forced-entry stepwise multivariable logistic regression was used to develop the prediction model, and performance was evaluated using C-statistic, calibration plot, and decision curve analysis. Internal validation was performed by bootstrapping.

RESULTS

In total, 310 patients were recruited for this study. 116 patients achieved the outcome. Forced-entry stepwise multivariable logistic regression indicated that PLA2Rab titer (OR = 1.002, 95% CI: 1.001-1.004, p = 0.003), inflammatory cells infiltration (OR = 2.753, 95% CI: 1.468-5.370, p = 0.002) and C3 deposition on immunofluorescence (OR = 0.217, 95% CI: 0.041-0.964, p = 0.049) were the three independent risk factors for treatment failure of PMN. The final prediction model had a C-statistic (95% CI) of 0.653 (0.590-0.717) and a net benefit of 23%-77%.

CONCLUSIONS

PLA2R antibody, renal interstitial inflammation infiltration, and C3 deposition on immunofluorescence were the three independent risk factors for treatment failure in PMN. Our prediction model might help identify patients at risk of treatment failure; however, the performance awaits improvement.

Anti-phospholipase A2 receptor positive membranous nephropathy: investigating the link between electron microscopy stages and clinical outcome

This retrospective, observational study sought to examine the relationship between Ehrenreich-Churg electron microscopy (EM) stages and long-term outcomes in anti-PLA2R membranous nephropathy (MN). Seventy-one patients with anti-PLA2R MN (median titer 185.7RU/mL) were followed for a median of 46 months, with end-stage kidney disease (ESKD) as the primary endpoint, and response to treatment as a secondary endpoint. Patients were grouped into stages I-II (41 patients) and stages III-IV (30 patients) for analytical purposes. Notably, the III-IV group demonstrated a lower eGFR, lower anti-PLA2R titer, but a higher chronicity score. Kaplan-Meier analysis showed shorter mean kidney survival time in stages III-IV compared to I-II (p 0.03). However, multivariate analysis using Cox regression indicated that Ehrenreich-Churg stages did not significantly influence kidney survival, but lower eGFR at diagnosis and higher histopathological chronicity score did. Remission was achieved by 64% of patients and no relationship between Ehrenreich-Churg stages and treatment response was found. The only identified risk factor for not achieving remission was the severity of hyposerinemia at diagnosis. In conclusion, while EM stages III-IV are associated with more chronic lesions and stages I-II with more active immunologic disease, the histological chronicity score seems to be a stronger predictor of long-term outcomes.

Nephrotic Syndrome and Statin Therapy: An Outcome Analysis

Background and Objectives: Hypercholesterolemia in patients with nephrotic syndrome (NS) may predispose to cardiovascular events and alter kidney function. We aimed to evaluate statins efficiency in NS patients under immunosuppression using four endpoints: remission rate (RR), end-stage kidney disease (ESKD), major cardiovascular events (MACE), and thrombotic complications (VTE). Materials and Methods: We retrospectively examined the outcome at 24 months after diagnosis of 154 NS patients (age 53 (39–64) years, 64% male, estimated glomerular filtration rate (eGFR) 61.9 (45.2–81.0) mL/min). During the follow-up, the lipid profile was evaluated at 6 months and at 1 and 2 years. Results: The median cholesterol level was 319 mg/dL, and 83% of the patients received statins. Patients without statins (17%) had similar age, body mass index, comorbidities, blood lipids levels, NS severity, and kidney function. The most used statin was simvastatin (41%), followed by rosuvastatin (32%) and atorvastatin (27%). Overall, 79% of the patients reached a form of remission, 5% reached ESKD, 8% suffered MACE, and 11% had VTE. The mean time to VTE was longer in the statin group (22.6 (95%CI 21.7, 23.6) versus 20.0 (95%CI 16.5, 23.5) months, p 0.02). In multivariate analysis, statin therapy was not associated with better RR, kidney survival, or fewer MACE; however, the rate of VTE was lower in patients on statins (HR 2.83 (95%CI 1.02, 7.84)). Conclusions: Statins did not improve the remission rate and did not reduce the risk of MACE or ESKD in non-diabetic nephrotic patients. However, statins seemed to reduce the risk of VTE. Further randomized controlled studies are needed to establish statins’ role in NS management.