Clinical features and outcomes of IgA nephropathy with nephrotic syndrome

A Mendelian randomization study investigating the causal relationships between inflammation and immunoglobulin A nephropathy

BACKGROUND

Immunoglobulin A nephropathy (IgAN) is an autoimmune disease characterized by the production of galactose‑deficient IgA1 (Gd‑IgA1) and the deposition of immune complexes in the kidney. Exploring the landscape of immune dysregulation in IgAN is valuable for pathogenesis and disease treatment. We conducted Mendelian randomization (MR) to assess the causal correlations between inflammation and IgAN.

METHODS

Based on available genetic datasets, we investigated potential causal links between inflammation and the risk of IgAN using two-sample MR. We used genome-wide association study (GWAS) summary statistics of 5 typical inflammation markers, 41 inflammatory cytokines, and 731 immune cell signatures, accessed from the public GWAS Catalog. The primary method employed for MR analysis was Inverse Variance Weighted (IVW). To confirm consistency across results, four supplementary MR methods were also conducted: MR-Egger, Weighted Median, Weighted Mode, and Simple Mode. To assess pleiotropy, we used the MR-Egger regression intercept test and Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO) test. Cochrane's Q statistic was applied to evaluate heterogeneity. Additionally, the stability of the MR findings was verified through the leave-one-out sensitivity analysis.

RESULTS

This study revealed that interleukin-7 (IL-7) and stem cell growth factor beta (SCGF-β) were possibly associated with the risk of IgAN according to the IVW approach, with estimated odds ratios (OR) of 1.059 (95 % confidence interval [CI] 1.015 to 1.104, P = 0.008) and 1.043 (95 % CI 1.002 to 1.085, P = 0.037). Five immune traits were identified that might be linked to IgAN risk, each with P-values below 0.01, including natural killer T %T cell (OR = 1.058, 95 % CI: 1.020 to 1.097, P = 0.002), natural killer T %lymphocyte (OR = 1.055, 95 % CI: 1.016 to 1.096, P = 0.006), CD25++ CD8+ T cell %T cell (OR = 1.057, 95 % CI: 1.016 to 1.099, P = 0.006), CD3 on effector memory CD4+ T cell (OR = 1.045, 95 % CI: 1.019 to 1.071, P = 0.001), and CD3 on CD28+ CD45RA+ CD8+ T cell (OR = 1.042, 95 % CI: 1.016 to 1.068, P = 0.001). CD4 on central memory CD4+ T cell might be a protective factor for IgAN (OR = 0.922, 95 % CI: 0.875 to 0.971, P = 0.002). Moreover, IgAN may be implicated in a high risk of elevated granulocyte colony-stimulating factor (G-CSF) (OR = 1.114, 95 % CI 1.002 to 1.239, P = 0.046).

CONCLUSION

Our study revealed exposures among typical inflammation markers, inflammatory cytokines, and immune cell signatures that may potentially linked to IgAN risk by MR analysis. This insight may advance our understanding of the etiology of IgAN and support the development of targeted therapeutic strategies.

Haemoglobin, albumin, lymphocyte, and platelet score as an independent predictor for renal prognosis in IgA nephropathy

Objective

The haemoglobin, albumin, lymphocyte, and platelet (HALP) score, a convenient and composite laboratory biomarker, can reflect inflammation and systemic nutritional status. This study was performed to investigate the effect of the HALP score on the prognosis of patients with IgA nephropathy (IgAN).

Methods

This is a retrospective single centre study that enrolled 895 biopsy-confirmed IgAN patients from June 2019 to June 2022 who were followed for more than 1 year. Kaplan-Meier curves and Cox regression analyses were performed to determine the relationship between HALP and adverse outcomes. The restricted cubic splines was used to identify the possible associations. The optimal cut-off value of HALP for renal poor outcome was identified by the area under the receiver operating characteristic curve (AUC).

Results

A total of 895 patients finally participated in the study and were divided into three groups (tertial 1-3) according to the baseline HALP score. More severe clinicopathologic features were observed in the lower HALP group, and Kaplan-Meier analysis showed patients in tertial 1 had a higher risk of kidney failure than the other groups (log-rank=11.02, P= 0.004). Multivariate Cox regression revealed that HALP score was an independent risk factor for renal prognosis in IgAN (adjusted HR: 0.967, 95% CI: 0.945-0.990, P = 0.006). The results of subgroup analysis suggested that HALP was more important in patients under the age of 50, BMI ≤ 23.9 and eGFR ≤ 90 mL/min/1.73 m2. The best cut-off HALP for renal survival was 38.83, sensitivity 72.1%, and specificity 55.9% (AUC: 0.662). Patients were further grouped according to HALP cut-off values and propensity matched. Multivariate Cox regression analysis revealed that HALP remained an independent predictor of IgAN in the matched cohort (HR 0.222, CI: 0.084-0.588, P=0.002).

Conclusion

HALP is a novel and potent composite parameter to predict kidney outcome in patients with IgAN.

Differences of clinicopathological characteristics and outcomes of IgA nephropathy patients with and without nephrotic syndrome

PURPOSE

To evaluate the differences in clinicopathological features and outcomes of IgA nephropathy (IgAN) patients with and without nephrotic syndrome.

METHODS

In this retrospective cohort study, IgAN patients from January 2006 to December 2011 in the First Affiliated Hospital of Sun Yat-sen University were enrolled and followed up to Dec 31, 2013. Logistic and Cox regression were conducted to evaluate the associated factors of nephrotic syndrome (NS) and its relation with outcomes of creatinine doubling and progression to end-stage kidney disease (ESKD).

RESULTS

A total of 1413 patients with IgAN were enrolled in this study, 57 (4.0%) of whom exhibited NS. Meanwhile, 13 (22.8%) of NS IgAN patients had minimal change disease (MCD). Logistic regression showed that more presence of hypertension, less glomerular sclerosis, less tubular atrophy/interstitial fibrosis, and lower density of IgA deposition in mesangial region were significantly associated with NS IgAN that were independent of age and gender. In addition, a total of 921 patients (890 with non-NS IgAN and 31 with NS IgAN) were followed up to Dec 31, 2013. After adjusting for age, sex, baseline estimated glomerular rate, hypertension and hemoglobin, no significant difference was observed in outcomes of serum creatinine doubling and ESKD between patients with or without NS IgAN.

CONCLUSIONS

Prevalence of NS IgAN patients was 4.0%, and 22.8% of them had MCD. Patients with NS IgAN had more severe clinical but less severe pathological features. However, outcomes of serum creatinine doubling and ESKD were not significantly different between patients with or without NS IgAN.

Distinct characteristics and prognosis of IgA nephropathy patients with nephrotic syndrome: a propensity score-matched cohort study

Introduction

IgA nephropathy (IgAN) is the most prevalent primary glomerulonephritis globally. While nephrotic syndrome (NS) is uncommon in IgAN, its significance remains unclear.

Methods

We conducted a retrospective analysis of 170 IgAN patients, classifying them into NS (n = 85) and non-NS (n = 5) groups. Our study aims to compare their clinical characteristics, treatment responses, and prognoses. Patients were selected based on renal biopsy from 2003 to 2020. Propensity score matching ensured comparability. Clinical, pathological, and immunological data were analyzed. Composite endpoints were defined as end-stage kidney disease (ESKD) or a 30% decline in estimated glomerular filtration rate (eGFR).

Results

NS patients showed higher eGFR (74.3 ± 36.8 vs. 61.5 ± 33.6 mL/min.1.73 m2, p = 0.02), severe hematuria (35.0 (4.7,147.5) vs. 4.0 (1.8,45,0) cells/μl, p < 0.001), severe foot process effacement (p = 0.01), and lower C3 levels (1.0 ± 0.3 vs. 1.1 ± 0.2 g/L, p = 0.03). In contrast, the non-NS group had higher BMI (24.3 ± 4.0 vs. 26.8 ± 3.7 kg/m2, p < 0.001) and elevated serum uric acid levels (376 (316,417) vs. 400 (362, 501) mmol/L, p = 0.001), suggesting metabolic factors might contribute to their condition. Both groups exhibited similar MESTC scores. NS patients had higher complete remission rates (26.2% vs. 14.1%, p = 0.04). Cox regression revealed NS independently associated with a higher risk of composite endpoints (HR = 1.97, 95% CI 1.05-3.72, p = 0.04). Linear mixed models did not show significant eGFR trajectory differences.

Discussion

This study has established that IgAN patients with NS exhibit distinct characteristics, including active disease and increased complement activation. NS is independently associated with a poorer prognosis, emphasizing the need for targeted interventions in this subgroup.

Are Platelet-Related Parameters Prognostic Predictors of Renal and Cardiovascular Outcomes in IgA Nephropathy?

Background: IgA nephropathy (IgAN) is associated with chronic inflammation. Platelet-related parameters, such as the platelet (PLT) count, platelet-to-albumin ratio (PAR), and platelet-to-lymphocyte ratio (PLR), were examined as potential prognostic indicators for renal and cardiovascular (CV) outcomes in IgAN. We were interested in whether platelet-related parameters are risk factors for ESKD and CV events in IgAN patients. Methods: In a monocentric retrospective study, 124 IgAN patients were divided into two groups based on the cut-off value of the PAR. All-cause mortality, major CV events, and end-stage renal disease were the primary combined endpoints. Secondary endpoints, such as CV or renal endpoints, were also analyzed separately. Results: The patients' mean age was 43.7 ± 13.5 years, and the follow-up time was 124 ± 67 months. The K-M curve showed that the PLR, PAR, and PLT were strongly associated with primary combined (p = 0.002, p = 0.004, p = 0.001) and renal outcomes (p < 0.001, p < 0.001, p < 0.001), but not with CV outcomes in IgAN. However, when combined with left ventricular hypertrophy (LVH) or metabolic syndrome (MetS), the PAR was found to be a significant predictor of both primary (p < 0.001, p < 0.001) and secondary outcomes (p = 0.001 and p = 0.038; p = 0.001 and p = 0.015). Additionally, the PLR correlated with albuminuria (r = -0.165, p = 0.033) and LVH (r = -0.178, p = 0.025), while PLT correlated with eGFR (r = 0.158, p = 0.040). Conclusions. Elevated PARs and PLRs may predict progression to end-stage kidney disease, but in combination with LVH and MetS, they were related to CV events in IgAN. The determination of PARs and PLRs can be useful and cost-effective parameters for assessing both cardiovascular and renal risks in IgAN.

IgA nephropathy in a boy with frequently relapsing nephrotic syndrome

A Japanese boy developed nephrotic syndrome (NS) and had microscopic hematuria at 8 years old. Renal biopsy was performed. Light microscopy study revealed mesangial proliferation and all immunofluorescent stains (including IgA) were negative, so he was diagnosed with non-IgA diffuse mesangial proliferation (DMP). Complete remission was achieved at 13 days after the initiation of oral prednisolone, and hematuria also disappeared 3 days later, but the patient developed frequently relapsing nephrotic syndrome. Cyclosporine A (CyA) was introduced at 10 years old, and there were no relapses between then and when it was discontinued at 12 years old. A second renal biopsy revealed minimal change without CyA nephrotoxicity. However, there was repeated relapse of NS after discontinuation, so CyA was reintroduced 8 months later, and NS remained in remission thereafter. Microscopic hematuria appeared at 13 years old, however, with gross hematuria appearing at the time of infection. A third renal biopsy revealed mesangial proliferation with IgA-dominant deposition, so the patient was diagnosed with IgA nephropathy. Currently (14 years old), CyA treatment has been discontinued and the patient is undergoing lisinopril therapy for IgA nephropathy, but there are still relapses of NS. To the best of our knowledge, there have been no previous reports of a patient with non-IgA DMP at the onset of NS who had later development of IgA nephropathy. The patient showed non-IgA DMP at the onset, suggesting that NS with non-IgA DMP and IgA nephropathy has some common pathophysiology. Treatment for NS, such as PSL and/or CyA treatment, may suppress the clinical manifestation of late IgA nephropathy.

Renal outcomes in IgA nephropathy following inactivated SARS-CoV-2 vaccination

INTRODUCTION

There are increasing case reports on de novo or relapsing IgA nephropathy (IgAN) following SARS-CoV-2 vaccines, although the follow-up information on renal outcomes in IgAN patients post-SARS-CoV-2 vaccination is limited. In this study, we evaluated the renal outcomes of IgAN patients following inactivated vaccines.

METHODS

We investigated the change in eGFR, proteinuria and hematuria in 113 primary IgAN patients post-vaccination. Worsening proteinuria was defined as an increase in proteinuria by more than 0.5 times and proteinuria > 1 g/d. Univariate and multivariable logistic regression analysis were used to evaluate possible predictors of worsening proteinuria. We then compared the renal outcomes of vaccinated patients after 6 months with 101 unvaccinated patients who were followed during the same period.

RESULTS

A 2.54% (0.64, 8.61) decrease in renal function was observed in post-vaccination patients. Subgroup analysis revealed a significant decrease in eGFR in patients with 30 ≤ eGFR < 60 (mL/min/1.73 m2) post second SARS-CoV-2 dose (n = 18, p = 0.01). In addition, 10 individuals displayed worsening proteinuria post-vaccination, with the proteinuria subsequently ameliorating significantly after 6-month. Multivariate analysis showed that higher eGFR levels was an independent protective factor for worsening proteinuria. The renal outcome tended towards a decrease in eGFR in vaccinated patients after 6 months follow-up, although the difference was not significant (p = 0.06).

CONCLUSION

Kidney function in IgAN patients tended to worsen after SARS-CoV-2 vaccination, particularly those with initial poor kidney function. This pattern of disease flare appears to be clinically mild, and further research is needed to determine whether the impact on kidney function is long-term.

Mild mesangial proliferative IgA nephropathy with and without minimal change disease

Mild mesangial proliferative IgA nephropathy with minimal change disease (MCD-IgAN) and mild mesangial proliferative IgA nephropathy without minimal change disease (Non-MCD-IgAN) have similar characteristics on light microscopy. Nevertheless, their discrepancies in clinicopathological features and prognosis remain unknown. A total of 589 patients with biopsy-proven mild mesangial proliferative IgA nephropathy (M-IgAN) combined with light microscopy and immunofluorescence were enrolled. Firstly, the diagnoses of the patients by electron microscopy were recorded and used as the gold standard. We calculated the sensitivity and specificity using nephrotic syndrome (NS) as the diagnostic criteria to identify MCD-IgAN. Then, excluding patients with a 24-h urinary total protein less than 0.5 g/day, incomplete clinical data, or less than the six-month follow-up, we included 184 cases of non-MCD-IgAN and 98 cases of MCD-IgAN. The patients' clinicopathological and outcome data were collected and compared. Among the 589 patients, according to electron microscopy, 381 were diagnosed with non-MCD-IgAN, 167 with MCD-IgAN, and 41 with M-IgAN complicated by other glomerular diseases. Using NS as the diagnostic criteria to distinguish non-MCD-IgAN and MCD-IgAN, the sensitivity and specificity were 83.8% and 99.5%, respectively. The patients in the MCD-IgAN group tended to be younger, hypotensive, with lower urinary erythrocytes, and more likely to achieve complete remission, and fewer patients progressed to the endpoint than those in the non-MCD-IgAN group (all P < 0 .05). NS appears to be an objective indicator for differentiating MCD-IgAN from non-MCD-IgAN. Non-MCD-IgAN varies greatly from MCD-IgAN in clinicopathology and treatment response, with a poorer prognosis.

Oral glucocorticoids with intravenous cyclophosphamide or oral glucocorticoids alone in the treatment of IgA nephropathy present with nephrotic syndrome and mesangioproliferative glomerulonephritis

Background

Few studies have evaluated the treatment of immunoglobulin A nephropathy (IgAN) patients with nephrotic syndrome (NS) and mesangioproliferative glomerulonephritis (MPGN). The aim of this study was to compare the therapeutic effects of oral glucocorticoids (GCS) combined with intravenous cyclophosphamide (CTX) and oral GCS alone in the treatment of the MPGN-IgAN patients with NS.

Methods

Biopsy-proven primary IgAN patients who were aged ≥14 years at diagnosis, had coexistent NS and MPGN and estimated glomerular filtration rate (eGFR) ≥15 mL/min/1.73 m2, and were treated by oral GCS combined with intravenous CTX or oral GCS alone for 6-12 months were retrospectively included. The patients in the GCS + CTX (prednisone 0.6-0.8 mg/kg/day and intravenous CTX 0.6-1.0 g monthly) or GCS (prednisone 0.8-1 mg/kg/day) group were rather matched at a 1:1 ratio on key characteristics by propensity score matching. The primary outcome was defined as either complete remission or partial remission at Month 24. The secondary outcome was a composite renal endpoint defined as a 50% decline in eGFR, doubling of serum creatinine or progression to end-stage kidney disease.

Results

Among the 146 IgAN patients who met the inclusion criteria, 42 patients were enrolled in the GCS + CTX group, and 42 patients were enrolled in the GCS group after propensity score matching. The clinical and histological parameters were similar between the two groups. Remission occurred more frequently in the GCS + CTX group at Month 6 (88.1% vs 52.4%, P < 0.001), Month 12 (88.1% vs 56.1%, P = 0.001) and Month 24 (85.0% vs 47.5%, P < 0.001) than in the GCS group. Moreover, subgroup analysis revealed that the higher response rate at Month 24 in the GCS + CTX group than in the GCS group was also present in different subgroups defined by sex, age, eGFR or Oxford MEST-C. Notably, we found that eGFR decreased at a lower rate in patients from the GCS + CTX group than in patients from the GCS group [eGFR slope: 0.05(-3.09, 3.67) vs -2.56 (-11.30, 0.86) mL/min/1.73 m2/year, P = 0.03]. Based on multivariate Cox regression analysis, GCS + CTX treatment was found to be independently associated with a decrease in risk for the composite endpoint after adjusted by the International Risk Prediction Score with race (hazard ratio = 0.17, 95% confidence interval 0.04-0.83, P = .03). There was no significant difference in adverse events (50.0% vs 42.9%, P = 0.51) or serious adverse events (7.1% vs 11.9%, P = .71) between the two groups.

Conclusions

Oral GCS combined with intravenous CTX is superior to GCS alone in treating MPGN-IgAN patients combined with NS. As the retrospective design and small sample size, our findings need to be validated by a prospective study.

Clinical significance of massive proteinuria in primary IgA nephropathy with and without nephrotic syndrome: a single center cohort study

BACKGROUND

Both primary IgA nephropathy (IgAN) with and without nephrotic syndrome (NS) can present massive proteinuria (24-h urinary protein ≥3.5 g/d). The clinical significance of massive proteinuria may be different in the two entities and needs further research.

METHODS

Data of 1870 patients with biopsy-proven IgAN in our hospital from January 2011 to December 2022 was retrospectively reviewed. A total of 242 IgAN patients with massive proteinuria were enrolled. Patients who presented with nephrotic syndrome at renal biopsy were included in the IgAN with NS cohort (IgAN-NS). The IgAN with nephrotic-range proteinuria cohort (IgAN-NR) consisted of 1:1 matched cases from the remaining according to age, gender, estimated glomerular filtration rate (eGFR) at baseline, and follow-up time. The clinical and pathological characteristics between the two cohorts were analyzed.

RESULTS

The IgAN-NS had a significantly higher proteinuria level than the IgAN-NR (p < .001). Cluster analysis revealed that proteinuria was associated with lipids in IgAN-NS, while it was associated with inflammatory indicators in IgAN-NR. When the complete remission of proteinuria (CR) was not achieved, the Kaplan-Meier analysis showed the prognosis of IgAN-NS was significantly worse than that of IgAN-NR (p = .04). Then, our GLMM model and line chart showed that the serum albumin level of the IgAN-NR was always evidently higher than that of the IgAN-NS while the significant difference in urinary albumin/creatinine ratio between the two cohorts gradually disappeared during the short-term follow-up (1 year). Moreover, the Cox regression analysis showed that the increased serum albumin was an independent protective factor for the poor outcomes (eGFR decreased from the baseline ≥ 30% continuously or reached end-stage renal disease [ESRD]).

CONCLUSION

The IgAN-NS had poorer clinicopathologic manifestation than IgAN-NR, including severer massive proteinuria. When the CR was not achieved, the prognosis of IgAN-NS was inferior to that of the IgAN-NR.

Cell-type-specific molecular characterization of cells from circulation and kidney in IgA nephropathy with nephrotic syndrome

Nephrotic syndrome (NS) is a relatively rare and serious presentation of IgA nephropathy (IgAN) (NS-IgAN). Previous research has suggested that the pathogenesis of NS-IgAN may involve circulating immune imbalance and kidney injury; however, this has yet to be fully elucidated. To investigate the cellular and molecular status of NS-IgAN, we performed single-cell RNA sequencing (scRNA-seq) of peripheral blood mononuclear cells (PBMCs) and kidney cells from pediatric patients diagnosed with NS-IgAN by renal biopsy. Consistently, the proportion of intermediate monocytes (IMs) in NS-IgAN patients was higher than in healthy controls. Furthermore, flow cytometry confirmed that IMs were significantly increased in pediatric patients with NS. The characteristic expression of VSIG4 and MHC class II molecules and an increase in oxidative phosphorylation may be important features of IMs in NS-IgAN. Notably, we found that the expression level of CCR2 was significantly increased in the CMs, IMs, and NCMs of patients with NS-IgAN. This may be related to kidney injury. Regulatory T cells (Tregs) are classified into two subsets of cells: Treg1 (CCR7 high, TCF7 high, and HLA-DR low) and Treg2 (CCR7 low, TCF7 low, and HLA-DR high). We found that the levels of Treg2 cells expressed significant levels of CCR4 and GATA3, which may be related to the recovery of kidney injury. The state of NS in patients was closely related to podocyte injury. The expression levels of CCL2, PRSS23, and genes related to epithelial-mesenchymal transition were significantly increased in podocytes from NS-IgAN patients. These represent key features of podocyte injury. Our analysis suggests that PTGDS is significantly downregulated following injury and may represent a new marker for podocytes. In this study, we systematically analyzed molecular events in the circulatory system and kidney tissue of pediatric patients with NS-IgAN, which provides new insights for targeted therapy in the future.

Potential benefits and related treatment effects of calcineurin inhibitors combined with steroid for IgA nephropathy: a systematic review and meta-analysis

BACKGROUND

IgA nephropathy is not uncommon for clinical practice. Within multiple options of treatment, it is alternatively to consider less well-studied immunosuppressants such as calcineurin inhibitors (CNI). The knowledge of CNI with steroid in the treatment of IgA nephropathy can be clarified via a systematic review and meta-analysis of randomized clinical trials.

METHODS

We performed the systematic search and meta-analysis for the randomized clinical trials of the CNI treatment in IgA nephropathy. The comparison between CNI combined with steroid and steroid-alone treatment was performed to find if the CNI combined with steroid can achieve more complete remission for IgA nephropathy. In addition, the related treatment effects were analyzed. After restricted selection, 16 studies with a total of 998 subjects with IgA nephropathy were enrolled. The focused outcome was complete remission, proteinuria, serum creatinine, and estimated glomerular filtration rate.

RESULTS

The meta-analysis showed higher odds ratio of complete remission if the patients received CNI with steroid combined treatment. The proteinuria can be significantly reduced under the combined treatment of CNI and steroid. However, the CNI with steroid combined treatment showed a non-superior effect on the parameters of serum creatinine and estimated glomerular filtration rate.

CONCLUSIONS

In current meta-analysis, the CNI combined with steroid treatment might show a trend to achieve complete remission status and reduce the proteinuria of IgA nephropathy when compared to steroid-alone treatment. However, no significant effects were observed in parameters of serum creatinine and estimated glomerular filtration rate.

Key pathological features characterize minimal change disease-like IgA nephropathy

AIMS

A subset of IgA nephropathy (IgAN) patients exhibiting minimal change disease (MCD) like features present with nephrotic-range proteinuria and warrants immunosuppressive therapy (IST). However, the diagnosis of MCD-like IgAN varied by reports. We aimed to identify the key pathological features of MCD-like IgAN.

METHODS

In this cohort, 228 patients had biopsy-proven IgAN from 2009 to 2021, of which 44 without segmental sclerosis were enrolled. Patients were classified into segmental (< 50% glomerular capillary loop involvement) or global (> 50%) foot process effacement (FPE) groups. We further stratified them according to the usage of immunosuppressant therapy after biopsy. Clinical manifestations, treatment response, and renal outcome were compared.

RESULTS

26 cases (59.1%) were classified as segmental FPE group and 18 cases (40.9%) as global FPE group. The global FPE group had more severe proteinuria (11.48 [2.60, 15.29] vs. 0.97 [0.14, 1.67] g/g, p = 0.001) and had a higher proportion of complete remission (81.8% vs. 20%, p = 0.018). In the global FPE group, patients without IST experienced more rapid downward eGFR change than the IST-treated population (-0.38 [-1.24, 0.06] vs. 1.26 [-0.17, 3.20]mL/min/1.73 m2/month, p = 0.004).

CONCLUSIONS

The absence of segmental sclerosis and the presence of global FPE are valuable pathological features that assist in identifying MCD-like IgAN.

Efficacy and safety of sequential immunosuppressive treatment for severe IgA nephropathy: A retrospective study

Background: This study compared the efficacy and safety of sequential immunosuppressive therapy in patients with non-end-stage IgA nephropathy (IgAN) with Lee’s classification of IV ∼ V and provided evidence for the use of immunotherapy in patients with severe IgAN.

Methods: We retrospectively analyzed the clinical data of patients with Lee’s IV ∼ V non-end-stage IgA nephropathy.

Results: 436 patients were diagnosed with IgAN, and 98 patients who met the inclusion criteria were included in this retrospective study. Of these, 17 were in the supportive care group, 20 in the P group (prednisone-only), 35 in P + CTX group (the prednisone combined with cyclophosphamide followed by mycophenolate mofetil), and 26 in the P + MMF group (prednisone combined with mycophenolate mofetil). The four groups showed differences in the segmental glomerulosclerosis score and the proportion of patients with Lee’s grade IV (p &lt; 0.05), but no differences in other indicators. Compared with the baseline values, urine protein-to-creatinine ratio (PCR) significantly decreased and serum albumin increased (p &lt; 0.05), but there was no significant difference between the groups. The estimated Glomerular Filtration Rate (eGFR) of the P, P + MMF, and P + CTX groups were higher than that of the supportive care group at the 6th and 24th month after treatment (all p &lt; 0.05). At the 24th month, the eGFR in the P + CTX group was higher than that in the P + MMF group (p &lt; 0.05). The effective remission rate of the P + CTX group was higher than that of the supportive care group (p &lt; 0.05). At 12 months, the effective remission rate of the P group was higher than that of the supportive care group (p &lt; 0.05). At the 24th month, there was no significant difference in the effective remission rates among the three groups (P, P + MMF, and P + CTX). Nine patients with severe IgA nephropathy reached the endpoint.

Conclusion: This study showed that immunosuppressive therapy insevere IgAN patient scan effectively reduce urinary protein, increase albumin, and protect renal function in the early stages of IgAN. P + CTX is the most commonly used, which has a high effective remission rate of urine protein and a low incidence of end-point events.

Characterization of patients with IgA nephropathy with and without associated minimal change disease

Introduction

Immunoglobulin A nephropathy (IgAN) presents various clinical manifestations and pathological phenotypes. Approximately 5% of patients with IgAN present with early onset nephrotic syndrome, mild mesangial lesions, and diffuse foot process effacement of podocytes, which resemble minimal change disease (MCD). These patients are defined as MCD-IgAN. Whether MCD-IgAN is a special type of IgAN or simply MCD accompanied by IgA deposition remains controversial.

Methods

A total of 51 patients diagnosed with MCD-IgAN at Beijing Anzhen Hospital from January 2010 to September 2022 were recruited. The clinical and pathological characteristics of IgA-MCD were analyzed. Patients with IgAN but without MCD (non-MCD-IgAN) and healthy participants were enrolled as controls. Galactose-deficient immunoglobulin A1 (Gd-IgA1) and complement C3 were detected both in the circulation and in renal tissues.

Results

We found that the levels of serum Gd-IgA1 were lower in participants with MCD-IgAN than in those with non-MCD-IgAN, but higher than in healthy participants. Gd-IgA1 was rarely deposited in the glomeruli of participants with MCD-IgAN, with a positive rate of only 13.7% (7/51); in contrast, the positive rate in participants with non-MCD-IgAN was 82.4% (42/51). Among renal Gd-IgA1-positive patients, Gd-IgA1 and immunoglobulin A (IgA) colocalized along the glomerular mesangial and capillary areas. Interestingly, we found that the circulating levels of complement C3 were significantly higher in participants with MCD-IgAN than in participants with non-MCD-IgAN. In addition, the intensity of C3c in glomeruli in participants with MCD-IgAN was significantly weaker than in participants with non-MCD-IgAN.

Conclusions

Our study suggests that, in MCD-IgAN, most of the IgA that is deposited on glomeruli is not the same pathogenic Gd-IgA1 as found in general IgAN. Complement activation both in the circulation and in the renal locality was much weaker in MCD-IgAN than in non-MCD-IgAN. Our study suggests that IgAN with MCD might be MCD with coincidental IgA deposition.

Clinicopathologic Manifestations of Immunoglobulin A Nephropathy in a Northern Indian Cohort: A Mute Assassin with Delayed Diagnosis

Introduction

Immunoglobulin A nephropathy (IgAN) is the most common glomerulonephritis worldwide, but there is a marked geographic difference in its prevalence and prognosis. IgAN is known to have an aggressive course in Asians. However, its exact prevalence and clinicopathologic spectrum in North India are not well documented.

Materials and Methods

The study included all patients aged above 12 years with primary IgAN on kidney biopsy from January 2007 to December 2018. Clinical and pathological parameters were noted. Two histopathologists independently reviewed all kidney biopsies, and MEST-C score was assigned as per the Oxford classification.

Results

IgAN was diagnosed in 681 (11.85%) out of 5751 native kidney biopsies. The mean age was 32 ± 12.3 years, and the male to female ratio was 2.5:1. At presentation, 69.8% had hypertension, 68% had an estimated glomerular filtration rate (eGFR) of less than 60 ml/min, 63.2% had microscopic hematuria, and 4.6% had gross hematuria. The mean proteinuria was 3.61 ± 2.26 g/day, with 46.8% showing nephrotic range proteinuria and 15.2% showing nephrotic syndrome manifestation. Histopathologically, 34.4% of patients had diffuse global glomerulosclerosis. Oxford MEST-C scoring revealed M1 in 67%, E1 in 23.9%, S1 in 46.9%, T1/T2 in 33%, and crescents in 19.6% of biopsies. The mean serum creatinine was significantly higher in cases with E1, T1/2, and C1/2 scores (P < 0.05). Hematuria and proteinuria were significantly higher (P < 0.05) with E1 and C1/2 scores. Coexisting C3 was associated with higher serum creatinine at presentation (P < 0.05).

Conclusion

IgAN patients with late presentation and advanced disease became less amenable to immunomodulation in our cohort. The implementation of point-of-care screening strategies, early diagnosis, and retarding disease progression should be prioritized in the Indian strategy.

The Role of NLRP3 Inflammasome in IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) is the most common primary glomerular disease worldwide today. The NLRP3 inflammasome is a polyprotein complex and an important participant in inflammation. Accumulating studies have shown that the NLRP3 inflammasome participates in a variety of kidney diseases, including IgAN. This review focuses on the role of the NLRP3 inflammasome in IgAN and summarizes multiple involved pathways, which may provide novel treatments for IgAN treatment.

Comparison between outcomes of IgA nephropathy with nephrotic-range proteinuria and nephrotic syndrome: do podocytes play a role?

Background

Nephrotic syndrome (NS) and nephrotic-range proteinuria (NRP) are uncommon in IgA nephropathy (IgAN), and their clinicopathology and prognosis have not been discussed. Podocytes may play an important role in both clinical phenotypes.

Methods

We investigated 119 biopsy-proven IgAN patients with proteinuria over 2 g/d. The patients were divided into three groups according to proteinuria level: the overt proteinuria (OP) group, NS group, and NRP group. In addition, according to the severity of foot process effacement (FPE), the patients were divided into three groups: the segmental FPE (SFPE) group, moderate FPE (MFPE) group, and diffuse FPE (DFPE) group. The outcome was survival from a combined event defined by a doubling of the baseline serum creatinine and a 50% reduction in eGFR or ESRD.

Results

Compared with the NRP group, patients in the NS group had more severe microscopic hematuria, presented with more severe endocapillary hypercellularity and had a higher percentage of DFPE. The Kaplan–Meier curve showed that MFPE patients had a better outcome in the NRP group <50% of tubular atrophy/interstitial fibrosis. In the multivariate model, the NRP group (HR = 17.098, 95% CI = 3.835–76.224) was associated with an increased risk of the combined event, while MFPE (HR = 0.260, 95% CI = 0.078–0.864; p = 0.028) was associated with a reduced risk of the combined event. After the addition of renin-angiotensin system inhibitors (RASi), the incidence of the combined event in the MFPE group (HR = 0.179, 95% CI = 0.047–0.689; p = 0.012) was further reduced.

Conclusions

NS presented more active lesions and more severe FPE in IgAN. NRP was an independent risk factor for progression to the renal endpoint, while MFPE indicated a better prognosis in NRP without obvious chronic renal lesions, which may benefit from RASi.

The clinical and pathological characteristics of IgA nephropathy patients in Tibet

Background

There are few studies on immunoglobulin A nephropathy (IgAN) at high altitude. This study aimed to analyze the clinical and pathological characteristics of IgAN between Tibet and Beijing, which provided a basis for improving diagnosis and treatment in Tibet.

Method

The clinical and pathological data of 80 patients from the People’s Hospital of Tibet Autonomous Region (Tibetan group) and 991 patients from Peking University First Hospital (Beijing group) with IgAN proven by renal biopsy were compared retrospectively between January 2016 and July 2020. The kidney biopsy tissue was sent to the Department of Nephrology, Peking University First Hospital for pathological evaluation.

Results

The proteinuria (2.9 [2.0, 4.9] vs. 1.1 [0.5, 2.4] g/day, P < 0.001) in the Tibetan group was significantly higher than that in the Beijing group. The serum albumin (30.4 ± 7.7 vs. 38.2 ± 5.5 g/L, P < 0.001) was significantly lower in the Tibetan group. The eGFR (77.7 ± 37.8 vs. 62.1 ± 33.6 ml/min/1.73 m², P = 0.001) was higher in the Tibetan group. The percentage of patients with nephrotic syndrome in the Tibetan group was significantly higher than that in the Beijing group (33.8% vs. 4.7%, P < 0.001).

Conclusion

There are differences in the clinical and pathological characteristics of IgAN between plateau and plain regions.

The difference between patients with nephrotic syndrome and nephrotic-range proteinuria in IgA nephropathy: a propensity score matched cohort study

Objective

To date, nephrotic syndrome (NS) has not been well characterized in patients with IgA nephropathy (IgAN). Whether decline in serum albumin is an ominous sign in IgAN patients with massive proteinuria remains unknown. In this study, we evaluated clinical and pathological features of IgAN with NS and compared the differences for these features and long-term outcomes between patients with nephrotic syndrome and nephrotic-range proteinuria.

Methods

A retrospective study was conducted, enrolling 1013 patients with biopsy-proven IgAN. The primary endpoint was the composite of a doubling of the base-line serum creatinine, 50% reduction in eGFR, ESKD (eGFR < 15 ml/min per 1.73 m²) or death.

Results

A total of 59 patients were presented with NS (5.8%). The patients with NS showed lower levels of hemoglobin, albumin and higher levels of serum creatinine, serum uric acid and urinary protein than patients without NS. As for pathological parameters, more patients with NS showed a higher prevalence of E1 lesions, T1/2 and C1/2 lesions. Furthermore, we used the propensity score matching method to select 57 patients with nephrotic-range proteinuria and normal serum albumin (NR group) who were comparable to 59 patients with NS. Patients with NS had lower levels of hemoglobin, albumin and IgG and higher levels of TC, LDL, FIB and D-dimer as well as more severe E1 and C1/2 lesions than those in NR group. The S1 lesion was more severe in the NR group than that in the NS group. There was no significant difference in long-term outcome between the two groups. In addition, we found that serum albumin level or the presence of hypoalbuminemia was not a risk factor affecting long-term outcome in patients with massive proteinuria.

Conclusions

A prevalence of 5.8% of NS was presented in IgAN adult patients in our study. IgAN with NS patients had low levels of hemoglobin, albumin, high levels of serum creatinine, serum uric acid, urinary protein and more acute lesions. The prognosis of NS in patients with IgAN was not inferior to that of patients with nephrotic range proteinuria and normal serum albumin.

C4d as a Screening Tool and an Independent Predictor of Clinical Outcomes in Lupus Nephritis and IgA Nephropathy

Background

As an indispensable marker of complement cascades activation, C4d was confirmed of its crucial role in the pathogenesis of both lupus nephritis (LN) and IgA nephropathy (IgAN). While the studies directly comparing the diagnostic value, and outcomes predicting function of C4d between LN and IgAN are still absent.

Methods

A cohort of 120 LN patients, 120 IgAN patients who were diagnosed by renal biopsy between January 2015 and December 2017 and 24 healthy age matched controls were prospectively analyzed. The patients were followed till December 2020. The outcomes were adverse disease treatment response (disease relapse) and kidney disease progression event (decline of estimated glomerular filtration rate by more than 20% or end-stage kidney disease). The renal C4d deposition proportion and pattern were compared between IgAN and LN patients. In addition, the relationship between renal C4d deposition and disease subtypes, disease relapse as well as disease progression for LN and IgAN patients were also analyzed.

Results

The LN, IgAN patients and healthy controls were well matched in ages. The follow-up period was 38.5 (30.3–60.8) months for LN patients and 45.0 (30.5–57.0) months for IgAN patients. 78 patients (65.0%) with LN had renal C4d deposition, compared with only 39 IgAN patients (32.5%) with C4d deposition in renal tissues (P < 0.001). The LN patients shared different renal C4d distribution patterns with IgAN patients. Compared with IgAN patients, the C4d deposition in LN patients was significantly more in renal glomerulus (P < 0.001) and less in renal tubules (P = 0.003). For disease subtypes, renal C4d deposition was especially strong in class V membranous LN and IgAN with tubulointerstitial fibrosis (T1/T2) lesions. Renal C4d deposition was independently correlated with the disease relapse of LN patients (HR = 1.007, P = 0.040), and acted as an independent predictor of disease progression during the follow-up period for IgAN patients (HR = 1.821, P = 0.040).

Conclusions

Renal C4d distribution proportion and pattern differed between LN and IgAN patients. The presence of C4d in renal tissue acted as an independent predictor of relapse for LN patients and disease progression for IgAN patients.

Immune Characteristics of IgA Nephropathy With Minimal Change Disease

Background: IgA nephropathy (IgAN) has a high degree of heterogeneity in clinical and pathological features. Among all subsets of IgAN, the pathogenesis of IgAN with minimal change disease (MCD-IgAN) remained controversial.

Methods: We analyzed the clinical and pathological characteristics of MCD-IgAN patients in a retrospective cohort. Patients diagnosed with IgAN, excluding MCD-IgAN, were randomly selected as controls. Levels of plasma galactose-deficient IgA1 (GdIgA1), IgG autoantibodies against GdIgA1, GdIgA1 deposition in the glomerulus, and inflammatory reactivity of circulating poly-IgA1 complexes to cultured mesangial cells were evaluated.

Results: Patients with MCD-IgAN had significantly higher levels of proteinuria and estimated glomerular filtration rate (eGFR), lower levels of albumin and urine blood cells, and milder histological lesions by a light microscope compared to IgAN patients, which bears a resemblance to MCD. Lower levels of GdIgA1 (3.41 ± 1.68 vs. 4.92 ± 2.30 μg/ml, p = 0.009) and IgG antiglycan autoantibodies (23.25 ± 22.59 vs. 76.58 ± 71.22 IU/ml, p < 0.001) were found in MCD-IgAN patients than those in IgAN controls. Meanwhile, weaker fluorescence intensities of both IgA and GdIgA1 were observed in the glomerulus of MCD-IgAN patients compared to those in IgAN patients. Furthermore, poly-IgA1 complexes from MCD-IgAN patients induced weaker inflammatory effects on cultured mesangial cells than those from IgAN patients in vitro.

Conclusion: The results demonstrated that MCD-IgAN cases represent a dual glomerulopathy, namely, mild IgAN with superimposed MCD, which furthermore provides substantial evidence for the corticosteroids therapy in MCD-IgAN patients as the guidelines recommended.

The Therapeutic Evaluation of Steroids in IgA Nephropathy Global (TESTING) Study: Trial Design and Baseline Characteristics

INTRODUCTION

Despite optimal current care, up to 30% of individuals suffering from immunoglobulin A nephropathy (IgAN) will develop kidney failure requiring dialysis or kidney transplantation. The Therapeutic Evaluation of STeroids in IgA Nephropathy Global (TESTING) study was designed to assess the benefits and risks of steroids in people with IgAN. We report the trial design as well as the baseline characteristics of study participants.

METHODS

It is an investigator-initiated, multicenter, double-blind, placebo-controlled, randomized trial of individuals with kidney biopsy-confirmed IgAN, proteinuria ≥1 g/day, and an estimated GFR of 20-120 mL/min/1.73 m2, following at least 3 months of standard of care including maximum labelled (or tolerated) dose of renin-angiotensin system blockade. The original study design randomized participants 1:1 to oral methylprednisolone (0.6-0.8 mg/kg/day, maximum 48 mg/day) for 2 months, with subsequent weaning by 8 mg/day/month over 6-8 months, or matching placebo. The intervention was modified in 2016 (due to an excess of serious infection) to low-dose methylprednisolone (0.4 mg/kg/day, maximum 32 mg/day) for 2 months, followed by weaning by 4 mg/day/month over 6-9 months, or matching placebo. Participants recruited after 2016 also received prophylaxis against Pneumocystis jirovecii pneumonia during the first 12 weeks of treatment.

RESULTS

The study recruitment period extended from May 2012 to November 2019. By the time the excess of serious infections was observed, 262 participants had been randomized to the original full-dose treatment algorithm, and an interim analysis was reported in 2016. Subsequently, 241 additional participants were randomized to a revised low-dose protocol, for a total of 503 participants from China (373), India (78), Canada (24), Australia (18), and Malaysia (10). The mean age of randomized participants was 38, 39% were female, mean eGFR at randomization was 62.7 mL/min/1.73 m2, and mean 24-h urine protein 2.54 g. The primary endpoint is a composite of 40% eGFR decline from baseline or kidney failure (dialysis, transplantation, or death due to kidney disease), and participants will be followed until the primary outcome has been observed in at least 160 randomized participants. Analyses will also be made across predefined subgroups. Effects on eGFR slope and albuminuria will also be assessed overall, as well as by the steroid dosing regimen.

CONCLUSIONS

The TESTING study (combined full and low dose) will define the benefits of corticosteroid use on major kidney outcomes, as well as the risks of therapy, and provide data on the relative effects of different doses, in individuals with high-risk IgAN.

Epidemiology and risk factors for progression in Chinese patients with IgA nephropathy

BACKGROUND

IgA nephropathy (IgAN) is one of the main causes of primary glomerulonephritis worldwide, and it is also the main primary disease leading to chronic kidney disease. The purpose of this study is to evaluate the epidemiology and risk factors for progression in Chinese patients with IgAN.

METHODS

In this retrospective study, 246 patients with renal biopsy-proven IgAN were enrolled from January 2012 to June 2018. The patients' data were divided into two groups according to eGFR at the end of follow-up: a high-eGFR group (eGFR≥60ml/min) and a low-eGFR group (eGFR<60ml/min).

RESULTS

At the end of the study, we identified 49 (19.92%) patients with low-eGFR from 246 IgAN patients. Renal function, represented by serum creatinine, urea nitrogen and cystatin-C, was significantly decreased in the low-eGFR group (P<0.001 for all) at the time of renal biopsy. Compared with the high-eGFR group, the age, mean arterial blood pressure (MAP), proteinuria, cholesterol, triglycerides and serum uric acid were significantly higher (P<0.05 for all). According to the Oxford evaluation, the proportion of S1-2 (59.2%) and T1-2 (65.3%) was significantly increased (P<0.001 for both) and the proportion that had a MEST-C score ≥3 was statistically increased in the low-eGFR group (83.7%, P=0.001).

CONCLUSIONS

Male, MAP, haematuria, Scr, cholesterol, hemoglobin, Lee classification more than 3 and C1-2 are independent risk factors for low-eGFR in Chinese IgAN patients.

High Neutrophil-To-Lymphocyte Ratio Is an Independent Risk Factor for End Stage Renal Diseases in IgA Nephropathy

Background

Complex factors are involved in the development and progression of immunoglobulin A nephropathy (IgAN), a common primary glomerulonephritis worldwide. Autoimmunity and inflammation have been considered to be the basic mechanisms; however, the exact pathogenesis remains unclear. As a novel marker of inflammation, the neutrophil-to-lymphocyte ratio (NLR) has been studied in various diseases. Whether the NLR can predict the renal outcome of patients with IgAN remains unclear. We evaluated the relationships between the NLR and renal function, pathologic lesions, renal progression, and prognosis in patients with IgAN.

Methods

This retrospective study involved 966 patients with biopsy-proven IgAN. They were divided into two groups based on the cut-off value of the NLR: the high group (NLR ≥ 2.67, n = 384) and the low group (NLR < 2.67, n = 582). The endpoint was end-stage renal disease [estimated glomerular filtration rate (eGFR) of <15 mL/min/1.73 m² or performance of renal replacement therapy]. A correlation test was conducted to explore the relationship between the NLR and other important parameters (eGFR, serum creatinine, proteinuria, hypertension and renal pathologic lesions). The predictive value was determined by the area under the receiver operating characteristics curve (AUROC). Kaplan–Meier and Cox proportional hazards analyses were performed to evaluate renal progression and prognosis.

Results

The NLR had the highest AUROC, which was 0.633 (p < 0.001). The correlation test revealed that the NLR was positively correlated with serum creatinine (r = 0.127, p < 0.001) and 24-hour urine protein (r = 0.18, p < 0.001) and negatively correlated with eGFR (r = 0.14, p < 0.001). Patients with IgAN who had a high NLR were more likely to have hypertension (p = 0.003). Multivariate Cox regression analysis indicated that a high NLR was an independent risk factor for IgAN even after adjustment for important clinical and pathological parameters (p = 0.043, HR = 1.74, 95%CI: 1.02-2.97). Kaplan–Meier analysis showed that a high NLR was significantly associated with the renal prognosis of patients with IgAN (p < 0.001), especially patients with stage 3 to 4 chronic kidney disease (p = 0.028) or 24-hour urine protein of >1 g/day (p < 0.001).

Conclusion

An elevated NLR affects the renal progression and prognosis in patients with IgAN and could be a marker for evaluation of renal function and pathologic lesions.

[Minimal change nephropathy and IgA deposits associated with a Sezary syndrome]

INTRODUCTION

The Sézary syndrome (SS) is an aggressive form of cutaneous T-cell lymphoma (CTCL) requiring a rapid diagnosis due to its poor prognosis.

CASE REPORT

We report the first case of an eighty-nine-year-old woman who presented with concomitant Sezary syndrome and anasarca, revealing a nephrotic syndrome caused by a minimal change nephropathy associated with immunoglobulin A (IgA) deposits. Scarce literature described rare cases associating these two entities (nephrotic syndrome and nephropathy). However, the nephrotic syndrome was delayed from disease onset, secondary to immunosuppressive treatment of SS, or due to the weaning of SS therapy. Thus, the direct link between the glomerular lesion and the cutaneous lymphoma was difficult to establish. However, the synchronous occurrence of both SS and glomerulopathy in our patient, along with Sezary cells in both urines (urinary cytology) and biopsy, and resolution of nephropathy after treatment of SS, support the likely attributability of SS in glomerulopathy.

CONCLUSION

Practitioners must acknowledge the possible occurrence of glomerular involvement in SS.

Leflunomide plus low-dose prednisone in patients with progressive IgA nephropathy: a multicenter, prospective, randomized, open-labeled, and controlled trial

Background

Immunoglobulin A nephropathy (IgAN) is the most common cause of glomerulonephritis worldwide, and the optimal approach to its treatment remains a significant challenge.

Methods

We did a prospective, randomized, open-labeled, multicenter, controlled trial, comprised of 3-month run-in, 12-month treatment, and 12-month follow-up phases. After 3-month run-in phase, patients with biopsy-confirmed IgAN at risk of progression were randomly allocated to LEF plus low-dose prednisone (LEF + prednisone group) or conventionally accepted-dose prednisone [prednisone(alone) group] Our primary outcome was 24-h urine protein excretion (UPE) and secondary outcomes were serum albumin (sALB), serum creatinine (Scr), and eGFR. Safety was evaluated in all patients who received the trial medications.

Results

One hundred and eight patients [59 in LEF + prednisone group, 49 in prednisone (alone) group]were enrolled and finished their treatment and follow-up periods. There is no significant difference in the baseline level between the two groups. Compared with baseline, both groups showed a significant decrease in 24-h UPE (p < 0.01) and increase in sALB (p < 0.01), with stable Scr and eGFR throughout the 12-month treatment period. What’s more, these effects were sustained through the 12-month follow-up period. However, there was no difference in 24-h UPE, sALB, Scr, and eGFR between the two groups (p > 0.05). At 12 months, a difference in overall response rate, relapsing rate, and incidence of adverse events between the two groups was not significant.

Conclusions

The efficacy and safety of LEF plus low-dose prednisone and conventionally accepted-dose prednisone in the treatment of progressive IgAN are comparable.

Cigarette smoking may accelerate the progression of IgA nephropathy

Background

Whether cigarette smoking is associated with the progression of immunoglobulin A nephropathy (IgAN) remains uncertain; therefore, we aimed to evaluate the effect of cigarette smoking on the prognosis of IgAN.

Methods

We divided 1239 IgAN patients from West China Hospital of Sichuan University who met the inclusion criteria into smoker (current or former) and non-smoker groups. The endpoint was end-stage renal disease (ESRD: eGFR < 15 mL/min/1.73 m² or undergoing renal replacement treatment) and/or eGFR decreased by > 50%. Kaplan–Meier, correlation, logistic regression and Cox proportional hazards analyses were performed. The association between cigarette smoking and IgAN was further verified by propensity-score-matched cohort analysis.

Results

During the mean follow-up period of 61 months, 19% (40/209) of the smoker group and 11% (110/1030) of the non-smoker group reached the study endpoint (p < 0.001). Multivariate Cox regression analysis revealed that cigarette smoking (hazard ratio (HR) = 1.58; p = 0.043) was an independent risk factor predicting poor renal progression in IgAN, and that IgAN patients with chronic kidney disease (CKD) stage 3–4 were more susceptible to cigarette smoking (p < 0.001). After propensity score matching (PSM), a significant correlation between cigarette smoking and renal outcomes in IgAN patients was seen. Furthermore, Spearman’s correlation test revealed that smoking dose was negatively correlated with eGFR (r = 0.141; p < 0.001) and positively related with proteinuria (r = 0.096; p = 0.001).

Conclusions

Cigarette smoking is an independent risk factor for IgAN progression, especially for advanced patients.

Primary IgA nephropathy with nephrotic-range proteinuria in Chinese children

To investigate the clinicopathological features and outcomes of primary IgA nephropathy with nephrotic-range proteinuria in Chinese children. Patients with biopsy-proven IgA nephropathy and nephrotic-range proteinuria between January 2011 and December 2017 were included, and their proteinuria and renal function were followed up. A total of 90 patients were enrolled, and 21.1% (19/90) of them had decreased renal function at diagnosis. Complete remission, partial remission, and no response of proteinuria occurred in 88.6% (70/79), 10.1% (8/79), and 1.3% (1/79), respectively, of the 79 patients who were followed up for 6 to 104 months. 73.7% (14/19) of the patients with decreased renal function at diagnosis recovered to normal level while 26.3% (5/19) of them did not recover or progressed to end-stage renal disease. Two patients with normal renal function at diagnosis progressed to renal insufficiency during follow-up period. By multivariate analysis, the risk for renal function deterioration was significantly higher in the partial remission and no response groups than in the complete remission group. Remission of proteinuria was important for improving renal prognosis in children with IgA nephropathy and nephrotic-range proteinuria. The outcomes for pediatric patients appeared to be better than that reported in adults.

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

INTRODUCTION

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

METHODS

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

RESULTS

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

CONCLUSION

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

Efficacy and safety of mycophenolate mofetil in the treatment for IgA nephropathy: a meta-analysis of randomized controlled trials

AIM

IgA nephropathy is virtually known as the most common glomerulopathy to end-stage renal failure in the world. Mycophenolate mofetil is a selective immunosuppressant widely used in organ transplantation, yet its tolerance and effectiveness in IgAN is controversial.

METHODS

This is a systematic review and random-effects meta-analysis, searching PubMed, Embase, Te Cochrane Library, Science Citation Index, Ovid evidence-based medicine, Chinese Biomedical Literature and Chinese Science and Technology Periodicals. Screen out randomized controlled trials on patients with biopsy-proven IgA nephropathy and analysis mycophenolate mofetil treatment regimens used for therapy of IgA nephropathy. Complete remission and partial remission, doubling of creatinine level, proteinuria, incidence of end-stage kidney disease, infection, Cushing syndrome, diabetes, hepatic dysfunction or gastrointestinal symptoms, neurologic or visual ambiguity, acne, and alopecia were observed.

RESULTS

Nine relevant trials were conducted with 587 patients enrolled. In Mycophenolate mofetil or plus medium/low-dose steroid comparing full-dose steroid alone or placebo, there was no significant difference. The risk of Cushing syndrome and diabetes had been significantly lowered with Mycophenolate mofetil-treated patients, while the risk of infection had been increased.

CONCLUSIONS

Mycophenolate mofetil therapy did not differ in reducing proteinuria and Scr in patients with IgAN who had persistent proteinuria, while having fewer Cushing syndrome and diabetes risk and more infection risk. However, larger randomized studies are needed to reveal these results.

Grading system utilising the total score of Oxford classification for predicting renal prognosis in IgA nephropathy

The Oxford classification of IgA nephropathy (IgAN) can evaluate each MEST-C score individually. We analysed a new grading system that utilised the total MEST-C score in predicting renal prognosis. Altogether, 871 IgAN patients were classified into three groups using the new Oxford classification system (O-grade) that utilised the total MEST-C score (O-grade I: 0–1, II: 2–4, and III: 5–7 points), and the 10-year renal prognosis was analysed. The clinical findings became significantly severer with increasing O-grades, and the renal survival rate by the Kaplan–Meier method was 94.1%, 86.9%, and 74.1% for O-grades I, II, and III, respectively. The hazard ratios (HRs) for O-grades II and III with reference to O-grade I were 2.8 (95% confidence interval [CI] 1.3–6.0) and 6.3 (95% CI 2.7–14.5), respectively. In the multivariate analysis, mean arterial pressure and eGFR, proteinuria at the time of biopsy, treatment of corticosteroids/immunosuppressors, and O-grade (HR 1.63; 95% CI 1.11–2.38) were the independent factors predicting renal prognosis. Among the nine groups classified using the O-grade and Japanese clinical-grade, the renal prognosis had an HR of 15.2 (95% CI 3.5–67) in the severest group. The O-grade classified by the total score of the Oxford classification was associated with renal prognosis.

Enumerating the role of properdin in the pathogenesis of IgA nephropathy and its possible therapies

BACKGROUND

IgA nephropathy (IgAN) has become the most prevalent form of glomerulonephritis affecting almost 1.3% of the total population worldwide. It is an autoimmune disorder where the host autoantibody forms an immune complex with the defective galactose-deficient IgA1 and gets deposited at the mesangium and endocapillary region of glomeruli. IgA has the capability to activate alternative and lectin complement cascades which even aggravates the condition. Properdin is directly associated with IgAN by activating and stabilising the alternative complement pathway at the mesangium, thereby causing progressive renal damage.

OBJECTIVE

The present review mainly focuses on correlating the influence of properdin in activating the complement cascade at glomeruli which is the major cause of disease exacerbation. Secondly, we have described the probable therapies and new targets that are under trials to check their efficacy in IgAN.

METHODS

An in-depth research was carried out from different peer-reviewed articles till December 2020 from several renowned databases like PubMed, Frontier, and MEDLINE, and the information was analysed and written in a simplified manner.

RESULTS

Co-deposition of properdin is observed along with IgA and C3 in 75%-100% of the patients. It is not yet fully understood whether properdin inhibition can attenuate IgAN, as many conflicting reports have revealed worsening of IgAN after impeding properdin.

CONCLUSION

With no specific cure still available, the treatment strategies are of great concern to find a better target to restrict the disease progression. More research and clinical trials are required to find out a prominent target to combat IgAN.

IgA Nephropathy: An Interesting Autoimmune Kidney Disease

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

LCC18, a benzamide-linked small molecule, ameliorates IgA nephropathy in mice

IgA nephropathy (IgAN), an immune complex-mediated process and the most common primary glomerulonephritis, can progress to end-stage renal disease in up to 40% of patients. Accordingly, a therapeutic strategy targeting a specific molecular pathway is urgently warranted. Aided by structure characterisation and target identification, we predicted that a novel ring-fused 6-(2,4-difluorophenyl)-3-(3-(trifluoromethyl)phenyl)-2H-benzo[e][1,3]oxazine-2,4(3H)-dione (LCC18) targets the NLRP3 inflammasome, which participates in IgAN pathogenesis. We further developed biomarkers for the disease. We used two complementary IgAN models in C57BL/6 mice, involving TEPC-15 hybridoma-derived IgA, and in gddY mice. Moreover, we created specific cell models to validate therapeutic effects of LCC18 on IgAN and to explain its underlying mechanisms. IgAN mice benefited significantly from treatment with LCC18, showing dramatically improved renal function, including greatly reduced proteinuria and renal pathology. Mechanistic studies showed that the mode of action specifically involved: (1) blocking of the MAPKs/COX-2 axis-mediated priming of the NLRP3 inflammasome; (2) inhibition of ASC oligomerisation and NLRP3 inflammasome assembly by inhibiting NLRP3 binding to PKR, NEK7 and ASC; and (3) activation of autophagy. LCC18 exerts therapeutic effects on murine IgAN by differentially regulating NLRP3 inflammasome activation and autophagy induction, suggesting this new compound as a promising drug candidate to treat IgAN. © 2020 The Pathological Society of Great Britain and Ireland. Published by John Wiley & Sons, Ltd.

Tris DBA ameliorates IgA nephropathy by blunting the activating signal of NLRP3 inflammasome through SIRT1- and SIRT3-mediated autophagy induction

Tris (dibenzylideneacetone) dipalladium (Tris DBA), a small‐molecule palladium complex, can inhibit cell growth and proliferation in pancreatic cancer, lymphocytic leukaemia and multiple myeloma. Given that this compound is particularly active against B‐cell malignancies, we have been suggested that it can alleviate immune complexes (ICs)–mediated conditions, especially IgA nephropathy (IgAN). The therapeutic effects of Tris DBA on glomerular cell proliferation and renal inflammation and mechanism of action were examined in a mouse model of IgAN. Treatment of IgAN mice with Tris DBA resulted in markedly improved renal function, albuminuria and renal pathology, including glomerular cell proliferation, neutrophil infiltration, sclerosis and periglomerular inflammation in the renal interstitium, together with (Clin J Am Soc Nephrol. 2011, 6, 1301‐1307) reduced mitochondrial ROS generation; (Am J Physiol‐Renal Physiol. 2011. 301, F1218‐F1230) differentially regulated autophagy and NLRP3 inflammasome; (Clin J Am Soc Nephrol. 2012, 7, 427‐436) inhibited phosphorylation of JNK, ERK and p38 MAPK signalling pathways, and priming signal of the NLRP3 inflammasome; and (Free Radic Biol Med. 2013, 61, 285‐297) blunted NLRP3 inflammasome activation through SIRT1‐ and SIRT3‐mediated autophagy induction, in renal tissues or cultured macrophages. In conclusion, Tris DBA effectively ameliorated the mouse IgAN model and targeted signalling pathways downstream of ICs‐mediated interaction, which is a novel immunomodulatory strategy. Further development of Tris DBA as a therapeutic candidate for IgAN is warranted.

Severity of foot process effacement is associated with proteinuria in patients with IgA nephropathy

Background

Proteinuria is a significant risk factor for progression of IgA nephropathy (IgAN) and has a positive correlation with severity of foot process effacement (FPE). We evaluated the relationship of FPE with proteinuria and histologic characteristics, including the Oxford classification.

Methods

Patients who underwent renal biopsy and were diagnosed with IgAN at a single center were retrospectively reviewed. Patients aged less than 18 years and those with the possibility of secondary causes were excluded from the study. Subsequently, we evaluated the association between degree of proteinuria, severity of FPE, and histologic characteristics, including the Oxford classification and other immunofluorescence stains.

Results

A total of 805 cases of renal biopsy was performed at our institution, and 327 patients were diagnosed with IgAN. Among them, 82 patients were excluded. Severity of FPE had an impact on the degree of proteinuria. Notably, the group with diffuse FPE had more than about 1.3 g/day of urine protein compared to those with rare FPE. Among the histologic characteristics, M1 score and immune deposition of IgG affected severity of FPE (hazard ratios [95% confidence interval], 1.90 [1.10 to 3.26], and 3.77 [1.66 to 8.54], respectively).

Conclusion

Severity of FPE had an impact on the degree of proteinuria and may be associated with the pathogenesis of IgAN.

Corticosteroids could improve the renal outcome of IgA nephropathy with moderate proteinuria

BACKGROUND

The specific treatment regimens of IgA nephropathy (IgAN) patients with moderate proteinuria (1.0-3.5 g/day) remain controversial. The purpose of this study was to explore the optimized therapeutic regimen for IgAN patients through analyzing the clinical data.

METHODS

A retrospective study was conducted, 449 patients with biopsy-proven IgAN were enrolled. Patients were divided into three groups according to proteinuria levels: urine protein 1.0-1.5 g/day (UP1, n = 111), urine protein 1.5-2.5 g/day (UP2, n = 213), urine protein 2.5-3.5 g/day (UP3, n = 125). Clinical pathological features, treatment regimens and renal outcome were compared. Responses to therapy included complete remission (CR), partial remission (PR), no response (NR) and end-stage renal disease (ESRD). The composite endpoints of renal outcome were defined as 50% decline in eGFR and/or progressing into end-stage renal disease.

RESULTS

During the average follow-up of 44.27 months, 71 (63.9%), 150 (70.4%) and 68 (54.4%) patients achieved CR + PR among three groups, respectively. Whereas 15 (13.5%), 28 (13.1%) and 39 (31.2%) patients progressed to the primary endpoint (P < 0.001). Patients who received corticosteroids (CS) treatment had better remission rate than those with supportive care (SC) or combined corticosteroid plus immunosuppressant (CS + IT) therapy (P < 0.05). Kaplan-Meier survival analysis revealed that patients received CS and CS + IT treatments had better renal prognosis compared with SC therapy in UP2 and UP3 groups (P < 0.05). However, no statistical difference was found among three treatment regimens in UP1 group (P = 0.358).

CONCLUSION

Corticosteroids therapy might better improve renal prognosis compared with supportive care alone or corticosteroids plus immunosuppressant in IgAN patients with moderate proteinuria (1.5-3.5 g/day).

Characterization of IgA Deposition in the Kidney of Patients with IgA Nephropathy and Minimal Change

Approximately 5% of patients with IgA nephropathy (IgAN) exhibit mild mesangial lesions with acute onset nephrotic syndrome and diffuse foot process effacement representative of minimal change disease (MCD). It is not clear whether these unusual cases of IgAN with MCD (IgAN-MCD) are variant types of IgAN or coincidental deposition of IgA in patients with MCD. In a retrospective multicenter cohort study of 18 hospitals in Korea, we analyzed 46 patients with IgAN-MCD. Patients with endocapillary proliferation, segmental sclerosis, and crescent were excluded, and the clinical features and prognosis of IgAN-MCD were compared with those of pure MCD. In addition, we performed galactose-deficient IgA1 (KM55) staining to characterize IgAN-MCD. Among the 21,697 patients with glomerulonephritis enrolled in the database, 46 patients (0.21%) were diagnosed with IgAN-MCD, and 1610 patients (7.4%) with pure MCD. The 46 patients with IgAN-MCD accounted for 0.6% of primary IgAN patients (n = 7584). There was no difference in prognosis between patients with IgAN-MCD and those with only MCD. IgA and KM55 showed double positivity in all patients with IgAN-MCD (n = 4) or primary IgAN (n = 5) under double immunofluorescent staining. However, in four patients with lupus nephritis, mesangial IgA was deposited, but galactose-deficient-IgA1 (Gd-IgA1) was not. These findings suggest that IgAN-MCD is a dual glomerulopathy in which MCD was superimposed on possibly indolent IgAN. We confirmed by KM55 staining that IgAN-MCD is true IgAN, enabling better characterizations of the disease. Furthermore, IgAN-MCD shows a good prognosis when treated according to the usual MCD treatment modality.

Remission of Proteinuria May Protect against Progression to Chronic Kidney Disease in Pediatric-Onset IgA Nephropathy

Immunoglobulin A nephropathy (IgAN) is one of the most common primary glomerulopathies diagnosed in children and adolescents. This study aimed to evaluate the clinical features in and outcomes of pediatric IgAN over the last 30 years. Patients who were diagnosed before age of 18 at 20 centers in Korea were evaluated retrospectively. Of the 1154 patients (768 males, 386 females) with a median follow-up of 5 years, 5.6% (n = 65) progressed to stage 3–5 chronic kidney disease (CKD). The 10- and 20-year CKD-free survival rates were 91.2% and 75.6%, respectively. Outcomes did not differ when comparing those in Korea who were diagnosed prior to versus after the year 2000. On multivariate analysis, combined asymptomatic hematuria and proteinuria as presenting symptoms and decreased renal function at the time of biopsy were associated with progression to CKD, while remission of proteinuria was negatively associated with this outcome. Patients who presented with gross hematuria or nephrotic syndrome tended toward positive outcomes, especially if they ultimately achieved remission. While remission of proteinuria might imply that the disease is inherently less aggressive, it also can be achieved by management. Therefore, more aggressive management might be required for pediatric-onset IgAN.

Steroid therapy in children with IgA nephropathy

IgA nephropathy (IgAN) is one the most common primary glomerulonephritis in children and adolescents worldwide, with 20% of children developing end-stage kidney disease (ESKD) within 20 years of diagnosis. There is a need for treatment guidelines, especially for steroids in children with primary IgAN, since the STOP-IgA trial casts doubts on the use of steroids in adults with intermediate risk. Pediatricians are prone to prescribe steroids in addition to renin-angiotensin system blockade (RASB) when proteinuria is > 0.5 g/l, eGFR deteriorates < 70 ml/min/1.73 m², or when a biopsy sample shows glomerular inflammation. Lack of randomized controlled trials (RCTs) in children with IgAN has led to an absence of consensus on the use of immunosuppressive agents in the treatment of progressive IgAN. This literature review evaluates the available evidence on steroid treatment in children with IgAN.

Treatment effects of Chinese medicine (Yi-Qi-Qing-Jie herbal compound) combined with immunosuppression therapies in IgA nephropathy patients with high-risk of end-stage renal disease (TCM-WINE): study protocol for a randomized controlled trial

Background

IgA nephropathy (IgAN) is the most common glomerular disease worldwide. It has a high incidence in Asians and is more likely to progress to end-stage renal disease (ESRD). For high-risk IgAN, which is clinically characterized by massive proteinuria and renal dysfunction, however, there has been no international consensus on treatment options. Compared with other developed countries, IgAN patients in China are often found to have severe kidney function loss at initial diagnosis. Yi-Qi-Qing-Jie formula (YQF; a compound recipe of Chinese medicinal herbs) has shown potential renal protection in our previous clinical studies. To further confirm the efficacy and safety of YQF in the treatment of high-risk IgAN, we have designed a prospective double-blind randomized placebo-controlled trial.

Methods/design

The TCM-WINE study is a single-center, prospective, double-blind randomized placebo-controlled trial. We plan to randomize 60 participants with biopsy-proven IgAN to a YQF combined group (YQF compound combined with prednisolone, and cyclophosphamide if necessary) or an immunosuppression group (placebo-YQF combined with prednisolone, and cyclophosphamide if necessary). The two groups will enter a 48-week in-trial treatment phase and receive post-trial follow-up until study completion (3 years). All patients will receive optimal supportive care. The primary composite outcome is defined as the first occurrence of a 40% decrease in estimated glomerular filtration rate (eGFR) from the baseline lasting for 3 months, initiating continuous renal replacement treatment, or death due to chronic kidney disease (CKD) during the 3-year study phase. The secondary endpoint events are defined as the mean annual eGFR decline rate (eGFR slope, ml/min per 1.73 m² per year), which is calculated by the eGFR regression curve for each eligible patient, and proteinuria remission (prescribed as proteinuria < 0.5 g/day) at weeks 24, 36, and 48 during the in-trial phase. The remission rate of symptoms and inflammation status will be evaluated at week 48. Safety monitoring and assessment will be undertaken during the study.

Discussion

The TCM-WINE study will evaluate the effects and safety of YQF combined therapy compared with immunosuppression monotherapy on the basis of the optimal supportive treatment in high-risk IgAN. The evidence from this study will provide a novel, effective, and safe Chinese characteristic therapy for high-risk IgAN patients.

Trial registration

ClinicalTrials.gov, NCT03418779. Registered on 18 June 2018.

Specific strains of Streptococcus mutans, a pathogen of dental caries, in the tonsils, are associated with IgA nephropathy

Streptococcus mutans is known to be a major causative agent of dental caries, and strains expressing the cell surface collagen-binding Cnm protein contribute to the development of several systemic diseases. A relationship between tonsillar immunity and glomerulonephritis has been recognized in IgA nephropathy (IgAN), and specific pathogens may have effects on tonsillar immunity (mucosal immunity). Here, we present findings showing a relationship between the presence of Cnm-positive S. mutans strains in the tonsils of IgAN patients and IgAN condition/pathogenesis. Analyses of tonsillar specimens obtained from patients with IgAN (n = 61) and chronic tonsillitis (controls; n = 40) showed that the Cnm protein-positive rate was significantly higher in IgAN patients. Among IgAN patients, the tonsillar Cnm-positive group (n = 15) had a significantly higher proportion of patients with high urinary protein (>1.5 g/gCr) and lower serum albumin level than the Cnm-negative group (n = 46). Additionally, Cnm protein and CD68, a common human macrophage marker, were shown to be merged in the tonsils of IgAN patients. These findings suggest that Cnm-positive S. mutans strains in the tonsils may be associated with severe IgAN.

Clinical and pathological features of immunoglobulin A nephropathy patients with nephrotic syndrome

IgA nephropathy (IgAN) is the most common glomerulonephritis worldwide. The classic manifestation of IgAN is episodic hematuria and proteinuria. Nephrotic syndrome (NS) is not very common in IgAN, reported to occur in only 5-10% of IgAN patients. However, the clinical and pathological characteristics and long-term outcomes of patients with NS-IgAN at onset remain unknown. A retrospective study was conducted, enrolling 1165 patients with biopsy-proven IgAN from West China Hospital in 2008-2015. Patients with renal biopsy of minimal change disease with mesangial IgA deposits were excluded. The renal endpoint was defined as 50% decrease in eGFR or progressing into end-stage renal disease (ESRD). A total of 1165 patients were enrolled with average age of 34.58, and 171 (14.7%) patients were presented with NS. Comparing NS and non-NS groups, significance differences were shown in hypertension (HTN), 24-h urine protein, serum albumin, serum creatine, eGFR and uric acid. NS group had severe pathological changes such as endocapillary hypercellularity, tubular atrophy or interstitial fibrosis and crescent, but less segmental glomerulosclerosis or adhesion and global sclerosis. During the average follow-up of 44.27 months, 29.8% (51/171) NS patients and 15.8% (157/994) non-NS patients progressed to the renal endpoint. 5-year renal survival rates were 73.1% and 87.8% (P < 0.001) in NS and non-NS groups, respectively. This study demonstrated that IgAN patients with NS had higher serum creatine, lower eGFR, lower uric acid, more acute lesions and poor prognosis. NS was an independent risk factor for progression to the renal endpoint.

Clinical and histological features and therapeutic strategies for IgA nephropathy

Chronic glomerulonephritis is the second most common reason, after diabetic nephropathy, for initiation of dialysis in Japan and IgA nephropathy (IgAN) is the most prevalent form of chronic glomerulonephritis. In the half century since IgAN was initially reported, our understanding of the long-term prognosis, clinical and histological features, pathogenesis of onset and progression, risk factors for progression, and appropriate treatment under different clinical and histological conditions, has steadily increased. Strong experimental and clinical evidence, the Clinical Practice Guidelines for IgA Nephropathy in Japan, the Oxford Classification, and the Kidney Disease Improving Global Outcomes guidelines have all contributed to the appropriate treatment of IgAN. Several intensive therapies, such as tonsillectomy, steroid therapy, and their combinations, can result in clinical remission, and prevent the progression to end stage renal disease (ESRD). However, some IgAN patients still progress to ESRD even when treated with intensive therapies. In this review, we discuss the clinical and histological features of IgAN, focusing primarily on our previous reports, and our opinions on therapeutic strategies for IgAN.

Crescents and Global Glomerulosclerosis in Chinese IgA Nephropathy Patients: A Five-Year Follow-Up

Background/Aims: This study aims to evaluate the clinical significance of crescent and global glomerulosclerosis formation on renal outcome in patients with IgA nephropathy (IgAN). Methods: Biopsy-proven primary IgAN patients from West China Hospital of Sichuan University were studied retrospectively between 2008 and 2015. Clinicopathological features and treatment modalities were recorded. The patients were divided into several groups on the basis of cellular and/or fibrocellular crescents scores and global glomerulosclerosis scores. Crescent (C) was scored according to the updated Oxford classification (C0/C1/C2). Global glomerulosclerosis (G) was scored according to the frequency of global glomerulosclerosis: G0 (≤25% of glomeruli), G1 (26–50% of glomeruli), and G2 (> 50% of glomeruli). The primary endpoint was defined as a 50% reduction in renal function or end stage renal disease. Patients were followed up for at least 12 months, or shorter if they reached study endpoints. 1328 patients with IgAN were recruited. Mean follow-up time was 46.1±23.6 months. The percentage of patients with C1 and C2 was 19.3% and 5.9% respectively. Higher crescent scores was associated with lower estimated glomerular filtration rates (eGFR), decreased serum albumin levels, increased amounts of urine protein, higher serum creatinine, as well as greater proportions of M1 and E1. The percentage of patients with G0, G1 and G2 was 70.5%, 20.7% and 8.8%, respectively. Elevated glomerulosclerosis scores were associated with lower eGFR levels, increased amounts of urine protein, higher levels of serum creatinine, higher incidences of arterial hypertension, as well as greater proportions of M1. There was a significantly higher proportion of T1/2 in patients with G2. In a multivariate model, crescent and global glomerulosclerosis were identified as independent predictors of decreased renal survival. Conclusion: Global glomerulosclerosis and crescents, as detected in renal biopsies, are strong predictors of long-term renal outcome of IgAN.

Paraneoplastic immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in asymptomatic low volume B-cell lymphoma - a case report

Background

Paraneoplastic glomerulonephritis is rare in haematological malignancies and tends to manifest as minimal change disease, membranous glomerulonephritis or membranoproliferative glomerulonephritis. We present the first report of immunoglobulin A nephropathy and associated focal segmental glomerulosclerosis in a patient with asymptomatic low grade B-cell lymphoma.

Case presentation

A 53 year old gentleman presented with nephrotic range proteinuria (urine protein creatinine ratio of 662 mg/mmol) on a background of type 2 diabetes mellitus (glycosylated haemoglobin: < 6%), hypertension, obesity (body mass index: 47.6 kg/m²) and degenerative spine disease. Bone marrow biopsy diagnosed a low grade B-cell lymphoma and renal biopsy was consistent with immunoglobulin A nephropathy. Lymphoma treatment with six cycles of cyclophosphamide/ rituximab/ prednisolone led to normalisation of urinary protein excretion (urine protein creatinine ratio: 14 mg/mmol at 26 months post-chemotherapy).

Conclusion

Paraneoplastic immunoglobulin A nephropathy can occur with a broad range of haematological malignancies regardless of stage. This case illustrates the importance of meticulous haematological system work-up for patients presenting with immunoglobulin A nephropathy. Recognition of paraneoplastic immunoglobulin A nephropathy and early diagnosis of associated malignancy can be life-saving.

Efficacy and safety of tacrolimus combined with glucocorticoid treatment for IgA nephropathy: a meta-analysis

Objective

As a classical immunosuppressant, tacrolimus (TAC) has been widely used in organ transplantation therapy, but the general benefits of TAC for the treatment of IgA nephropathy (IgAN) remain uncertain. We conducted a meta-analysis to examine the effects of TAC combined with glucocorticoid on IgAN.

Methods

We searched the information databases PubMed/Medline, Embase, Science Citation Index, Chinese Biomedical Literature and the Chinese databases VIP, CNKI and Wan Fang for randomized controlled trials of TAC combined with glucocorticoid as a therapy for IgAN.

Results

Ten relevant studies involving 472 patients were included in a meta-analysis. Overall, the TAC group showed a significant decrease in proteinuria compared with the control group (MD: −0.18 g/d, 95% CI: −0.32 to −0.04). No increased risk of adverse events was observed (OR: 0.93, 95% CI: 0.65 to 1.33). In general, the TAC group showed good tolerance.

Conclusion

Evidence to date clearly indicates that TAC combined with glucocorticoid is quite effective in reducing proteinuria and albuminuria in patients with IgAN. Moreover, we found that patients receiving TAC therapy did not show an increased risk of side effects compared with control group patients. TAC combined with glucocorticoid is a promising medication and merits further research.

Comparison of combined leflunomide and low-dose corticosteroid therapy with full-dose corticosteroid monotherapy for progressive IgA nephropathy

IgA nephropathy is the most common primary glomerulonephritis and one of the leading causes of end-stage renal disease. We performed a randomized, controlled, prospective, open-label trial to determine whether leflunomide combined with low-dose corticosteroid is safe and effective for the treatment of progressive IgA nephropathy, as compared to full-dose corticosteroid monotherapy. Biopsy-proved primary IgA nephropathy patients with an estimated glomerular filtration rate ≥ 30 ml/min/1.73m² and proteinuria ≥1.0 g/24h were randomly assigned to receive leflunomide+low-dose corticosteroid (leflunomide group; n = 40) or full-dose corticosteroid (corticosteroids group; n = 45). The primary outcome was renal survival; secondary outcomes were proteinuria and adverse events. After 12 months of treatment and an average follow-up of 88 months, 11.1% vs. 7.5% of patients reached end-stage renal disease and 20% versus 10% of patients had a ≥ 50% increase in serum creatinine in the corticosteroids and leflunomide groups, respectively. Kaplan-Meier analysis did not reveal a between-group difference in these outcomes. Decreases in 24-hour proteinuria were similar in the two groups during the treatment period, but a more marked reduction was observed during follow-up in the leflunomide group. Although the incidence of adverse events was similar in the two groups, serious adverse events were observed only in the corticosteroid group. Thus, leflunomide combined with low-dose corticosteroid is at least as effective as corticosteroid alone for the treatment of progressive IgA nephropathy, and showed a greater reduction of proteinuria during long-term follow-up and fewer severe adverse events.