Membranous nephropathy in Japan: analysis of the Japan Renal Biopsy Registry (J-RBR)

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

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

A case of neuron-derived neurotrophic factor-positive, syphilis-related membranous nephropathy that achieved spontaneous remission

Neuron-derived neurotrophic factor (NDNF) was discovered as a target antigen in membranous nephropathy (MN) caused by syphilis. However, there have been few reports of NDNF-positive MN in Japan. A 19-year-old female patient was admitted to our hospital with nephrotic syndrome and acute kidney injury. After admission, she presented with a skin rash and was serologically positive for syphilis. Kidney biopsy showed MN positive not only for immunoglobulin (Ig) G, but also for IgA and complement C1q. IgG subclass analysis revealed positivity for IgG1 and IgG3. Immunohistochemistry for glomerular NDNF was positive, and a diagnosis of syphilis-related MN was confirmed. Prior to treatment of the infection, her urinary protein decreased to achieve complete remission and her kidney function improved. Benzylpenicillin was administered, and no recurrence of nephrotic syndrome or kidney dysfunction was observed thereafter. This case illustrates the importance of considering syphilis infection when encountering a case of nephrotic syndrome with skin rash. In addition, urinalysis of syphilitic patients should be performed to avoid missing MN that may be in spontaneous remission. Further elucidation of the pathogenesis of NDNF-positive, syphilis-related MN in Japan is needed.

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

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

Fecal microbiota transplantation in autoimmune diseases - An extensive paper on a pathogenetic therapy

The role of infections in the pathogenesis of autoimmune diseases has long been recognized and reported. In addition to infectious agents, the internal composition of the "friendly" living bacteria, (microbiome) and its correlation to immune balance and dysregulation have drawn the attention of researchers for decades. Nevertheless, only recently, scientific papers regarding the potential role of transferring microbiome from healthy donor subjects to patients with autoimmune diseases has been proposed. Fecal microbiota transplantation or FMT, carries the logic of transferring microorganisms responsible for immune balance from healthy donors to individuals with immune dysregulation or more accurately for our paper, autoimmune diseases. Viewing the microbiome as a pathogenetic player allows us to consider FMT as a pathogenetic-based treatment. Promising results alongside improved outcomes have been demonstrated in patients with different autoimmune diseases following FMT. Therefore, in our current extensive review, we aimed to highlight the implication of FMT in various autoimmune diseases, such as inflammatory bowel disease, autoimmune thyroid and liver diseases, systemic lupus erythematosus, and type 1 diabetes mellitus, among others. Presenting all the aspects of FMT in more than 12 autoimmune diseases in one paper, to the best of our knowledge, is the first time presented in medical literature. Viewing FMT as such could contribute to better understanding and newer application of the model in the therapy of autoimmune diseases, indeed.

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

Background

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

Methods

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

Results

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

Conclusions

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

Successful treatment of coexisting membranous nephropathy and immune thrombocytopenia by eradicating gastric Helicobacter pylori infection: a case report

Membranous nephropathy (MN) is a common cause of nephrotic syndrome in middle-aged and older adults. MN etiology is mainly primary or idiopathic; however, it may also be secondary to infections, drugs, neoplasms, and autoimmune diseases. We present the case of a 52-year-old Japanese man with coexisting nephrotic MN and immune thrombocytopenic purpura (ITP). Renal biopsy revealed glomerular basement membrane thickening with immunoglobulin (Ig) G and complement component 3 deposition. Glomerular IgG subclass analysis revealed predominant IgG4 deposition with weak IgG1 and IgG2 deposition. IgG3 and phospholipase A2 receptor deposits were negative. Upper endoscopy revealed no ulcers, but histological examination demonstrated Helicobacter pylori infection in the gastric mucosa with elevated IgG antibodies. After gastric Helicobacter pylori eradication, the nephrotic-range proteinuria and thrombocytopenia of the patient were markedly improved without initiation of immunosuppressive treatment. Therefore, clinicians should consider the possibility of Helicobacter pylori infection in patients with coexisting MN and ITP. Further studies are required to demonstrate the associated pathophysiological aspects.

Changes in spectrum of biopsy-proven kidney diseases within decade: an analysis based on 10 199 cases from South China

PURPOSE

To assess the regional epidemiological trends of kidney diseases over time in the South China using renal biopsy-proven cases.

METHODS

This retrospective observational cohort study was conducted at the Institute of Nephrology, Second Xiangya Hospital of Central South University, and encompasses all patients diagnosed with kidney disease via biopsy from 2012 to 2021.

RESULTS

The study sample consisted of 10 199 native kidneys, with a male-to-female ratio of 0.91:1 and an average age of 38.74 (±14.53) years. Primary glomerular nephropathy, systemic glomerular nephropathy (SGN), tubulointerstitial disease, and hereditary renal diseases accounted for 66.92 (6825)%, 24.49 (2498)%, 8.06 (822)%, and 0.53 (54)%, respectively. The leading pathologies of primary glomerular nephropathy remained the IgA nephropathy. The frequencies of IgA nephropathy and membranous nephropathy increased significantly, whereas the frequencies of minimal change disease and focal segmental glomerulosclerosis decreased (P < .001) between 2017 and 2021 than in the years 2012 and 2016. An earlier onset of membranous nephropathy was observed in the age group of 45-59 years compared to previous studies. The leading pathologies of SGN were found to be lupus nephritis (758 cases, 30.45%) and hypertension nephropathy (527 cases, 21.17%). The frequencies of hypertension nephropathy and diabetic nephropathy increased between 2017 and 2021 compared to 2012 and 2016 (P < .001), gradually becoming the leading pathological types of SGN. In elderly patients diagnosed with nephrotic syndrome, the frequencies of amyloidosis significantly increased (P < .01).

CONCLUSION

Our study may provide insights for kidney disease prevention and public health strategies. What is already known on this topic The pathological spectrum of kidney diseases has undergone significant transformations in the past decade, driven by the escalating incidence of chronic diseases. Although there are studies exploring the renal biopsy findings from various regions in China which present both similarities and differences in epidemiology, few large-scale reports from the South China in recent decades were published. What this study adds Our findings reveal the following key observations: (i) increased proportion of middle-aged patients leading to the increasing average age at the time of biopsy；(ii) the frequencies of IgA nephropathy and membranous nephropathy (MN) increased significantly, whereas the frequencies of minimal change disease and focal segmental glomerulosclerosis decreased (P < .001) between 2017 and 2021 than in the years 2012 and 2016; (iii) earlier onset of MN in the age group of 45-59 years old was found in our study; and (iv) a higher frequency of hypertension nephropathy and DN presented over time, and frequency of amyloidosis increased in elderly patients diagnosed with NS. How this study might affect research, practice, or policy This single-center yet a large-scale study of the kidney disease spectrum in South China may provide a reference point for the diagnosis, treatment, and prevention of chronic kidney disease.

Containing anti-PLA2R IgG antibody induces podocyte injury in idiopathic membranous nephropathy

Background: Idiopathic membranous nephropathy is widely recognized as an autoimmune kidney disease that is accompanied by the discovery of several autoantibodies, and the antibody subclass in the circulation of patients with iMN is mainly IgG. However, the direct pathogenic effect of the containing anti-PLA2R IgG antibody on podocytes is not clear.Method: A protein G affinity chromatography column was used to purify serum IgG antibodies. Containing anti-PLA2R IgG antibodies from iMN patients and IgG from healthy controls were also obtained. Based on the established in vitro podocyte culture system, purified IgG antibodies from the two groups were used to stimulate podocytes, and the expression of essential podocyte proteins (podocin), the levels of inflammatory cytokines in the cell supernatant, cytoskeletal disorders, and podocyte apoptosis were analyzed.Results: Compared with that in the normal IgG group, the expression of podocin and podocin mRNA was reduced (p = 0.016 and p = 0.005, respectively), the fluorescence intensity of podocin on the surface of podocytes was reduced, the cytoskeleton of podocytes was disordered and reorganized, and the ratio of podocyte apoptosis was increased in the iMN group (p = 0.008).Conclusion: The containing anti-PLA2R IgG antibody might have a direct damaging effect on podocytes in idiopathic membranous nephropathy.

Chapter 1: Evaluation of kidney function in patients undergoing anticancer drug therapy, from clinical practice guidelines for the management of kidney injury during anticancer drug therapy 2022

The prevalence of CKD may be higher in patients with cancer than in those without due to the addition of cancer-specific risk factors to those already present for CKD. In this review, we describe the evaluation of kidney function in patients undergoing anticancer drug therapy. When anticancer drug therapy is administered, kidney function is evaluated to (1) set the dose of renally excretable drugs, (2) detect kidney disease associated with the cancer and its treatment, and (3) obtain baseline values for long-term monitoring. Owing to some requirements for use in clinical practice, a GFR estimation method such as the Cockcroft-Gault, MDRD, CKD-EPI, and the Japanese Society of Nephrology's GFR estimation formula has been developed that is simple, inexpensive, and provides rapid results. However, an important clinical question is whether they can be used as a method of GFR evaluation in patients with cancer. When designing a drug dosing regimen in consideration of kidney function, it is important to make a comprehensive judgment, recognizing that there are limitations regardless of which estimation formula is used or if GFR is directly measured. Although CTCAEs are commonly used as criteria for evaluating kidney disease-related adverse events that occur during anticancer drug therapy, a specialized approach using KDIGO criteria or other criteria is required when nephrologists intervene in treatment. Each drug is associated with the different disorders related to the kidney. And various risk factors for kidney disease associated with each anticancer drug therapy.

Anti-phospholipase A2 Receptor Antibody-Negative Membranous Nephropathy in Pregnancy

Nephrotic syndrome in pregnancy is associated with challenges for both patients and physicians. Early recognition is crucial, and when appropriate, renal biopsy should be considered to differentiate preeclampsia from other causes of glomerulopathies. Pregnancy in a woman with nephrotic syndrome is high risk, and more data are needed to highlight pregnancy outcomes.

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

Key Points

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

Background

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

Methods

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

Results

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

Conclusions

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

Twenty-four-Year Trends in Incidence and Mortality of Nephrotic Syndrome: A Population-Based Cohort Study

BACKGROUND

With the increasing prevalence of risk factors for nephrotic syndrome, updated epidemiologic data on the syndrome are needed. We examined its age- and sex-specific incidence, histopathology, and mortality over 24 years.

METHODS

This nationwide cohort study included all adults with first-time-recorded nephrotic syndrome in Denmark during 1995-2018 using the Danish National Patient Registry. We obtained data on age, sex, hospital-diagnosed comorbidities, and histopathologic findings. We computed overall, and age- and sex-specific, incidence rates of nephrotic syndrome, 1- and 5-year mortality by calendar period, and 1-year hazard ratios (HRs) of death using Cox models.

RESULTS

We identified 3,970 adults with first-time nephrotic syndrome diagnosis. Incidence was highest in men and increased with age to 11.77 per 100,000 person-years (95% confidence interval [CI]: 10.21-13.32) in men aged 80+ years, and 6.56 per 100,000 person-years (95% CI: 5.71-7.41) in women aged 80+ years. Incidence of nephrotic syndrome increased from 3.35 per 100,000 person-years (95% CI: 3.12-3.58) in 1995-2000 to 4.30 per 100,000 person-years (95% CI: 4.05-4.54) in 2013-2018. Over time, 1-year mortality of nephrotic syndrome was stable at 13%-16%, but HR of death was 0.54 (95% CI: 0.42-0.69), adjusted for age, sex, and comorbidities, in 2013-2018 compared with 1995-2000. Subdistribution of glomerulopathies was stable over time with membranous nephropathy and minimal change disease being the most common.

CONCLUSION

During 1995-2018, the incidence of recorded adult nephrotic syndrome increased slightly, and the adjusted mortality of nephrotic syndrome decreased markedly. Whether these findings reflect changes in epidemiology or awareness and coding of nephrotic syndrome, remains to be clarified.

Prevalence and Pattern of Glomerulonephritis: An Experience of Two Tertiary Centers in Malaysia

The prevalence of glomerulonephritis (GN), especially membranous GN (MGN), changes from time to time. This change may be due to genetic predisposition, environmental factors race, age, and indications for a renal biopsy. This study was conducted to evaluate the distribution and changing patterns of GN by further assessing the prevalence of MGN. A 1000, 123 biopsies were performed from January 2012 to October 2019 in Hospital Serdang and Hospital Kuala Lumpur. Electron microscopy, immunohistochemistry, and clinical presentations were used to differentiate primary and secondary MGN, from which 611 and 457 primary and secondary subjects were diagnosed with primary and secondary GN, respectively. Primary MGN accounts for 13% of all the primary GN, while lupus nephritis (LN) accounts for 44.2% of all secondary GN followed by diabetes mellitus (25.6%). The proportions of primary and secondary MGN were 64.8% and 35.2%, respectively, with a male-to-female ratio of 1:1.1 in favor of females. The renal biopsy obtained from the registry of two prominent hospitals in Malaysia provided valuable prevalence and demonstrated changes in the prevalence of GN in Malaysia. Notwithstanding, immunoglobulin A nephropathy and LN remain the most common causes of primary and secondary GN in Malaysia.

Predictors of early remission of proteinuria in adult patients with minimal change disease: a retrospective cohort study

Previous studies reported conflicting results regarding an association between serum albumin concentration and the cumulative incidence of remission of proteinuria in adult patients with minimal change disease (MCD). The present study aimed to clarify the clinical impact of serum albumin concentration and the cumulative incidence of remission and relapse of proteinuria in 108 adult patients with MCD at 40 hospitals in Japan, who were enrolled in a 5-year prospective cohort study of primary nephrotic syndrome, the Japan Nephrotic Syndrome Cohort Study (JNSCS). The association between serum albumin concentration before initiation of immunosuppressive treatment (IST) and the cumulative incidence of remission and relapse were assessed using multivariable-adjusted Cox proportional hazards models. Remission defined as urinary protein < 0.3 g/day (or g/gCr) was observed in 104 (96.3%) patients. Of 97 patients with remission within 6 month of IST, 42 (43.3%) developed relapse defined as ≥ 1.0 g/day (or g/gCr) or dipstick urinary protein of ≥ 2+. Serum albumin concentration was significantly associated with remission (multivariable-adjusted hazard ratio [95% confidence interval] per 1.0 g/dL, 0.57 [0.37, 0.87]), along with eGFR (per 30 mL/min/1.73 m²: 1.43 [1.08, 1.90]), whereas they were not associated with relapse. A multivariable-adjusted model showed that patients with high eGFR level (≥ 60 mL/min/1.73 m²) and low albumin concentration (≤ 1.5 g/dL) achieved significantly early remission, whereas those with low eGFR (< 60 mL/min/1.73 m²) and high albumin concentration (> 1.5 g/dL) showed significantly slow remission. In conclusion, lower serum albumin concentration and higher eGFR were associated with earlier remission in MCD, but not with relapse.

Time to remission of proteinuria and incidence of relapse in patients with steroid-sensitive minimal change disease and focal segmental glomerulosclerosis: the Japan Nephrotic Syndrome Cohort Study

BACKGROUND

Minimal change disease (MCD) is characterized by a nephrotic syndrome usually steroid-sensitive and a high incidence of relapse of proteinuria. Previous cohort studies have reported conflicting results regarding the association between the time to remission and incidence of relapse.

METHODS

This multicenter prospective cohort study included 102 adult patients with steroid-sensitive MCD or focal segmental glomerulosclerosis from a 5-year cohort study of primary nephrotic syndrome, the Japan Nephrotic Syndrome Cohort Study, who achieved remission of proteinuria within 2 months of immunosuppressive therapy (IST). The association between the time to remission of proteinuria after immunosuppressive therapy and incidence of relapse was assessed using Cox proportional hazards models adjusted for clinically relevant factors.

RESULTS

Remission was observed at 3-7, 8-14, 15-21, 22-28, and 30-56 days after initiation of immunosuppressive therapy in 17 (16.7%), 37 (36.3%), 21 (20.6%), 13 (12.7%), and 14 (13.7%) patients, respectively. During a median observation period of 2.3 years after the end of the 2nd month after initiation of immunosuppressive therapy, 46 (45.1%) patients relapsed. The time to remission was associated with the incidence of relapse in an inverse U-shaped pattern (multivariable-adjusted hazard ratios [95% confidence intervals] of the time to remission of 3-7, 8-14, 15-21, 22-28, 30-56 days: 1.00 [reference], 1.76 [0.56, 5.51], 6.06 [1.85, 19.80], 5.46 [1.44, 20.64], and 2.19 [0.52, 9.30], respectively).

CONCLUSION

The time to remission was identified as a significant predictor of relapse in steroid-sensitive patients.

B Cells in Primary Membranous Nephropathy: Escape from Immune Tolerance and Implications for Patient Management

Membranous nephropathy (MN) is an important cause of nephrotic syndrome and chronic kidney disease (CKD) in adults. The pathogenic significance of B cells in MN is increasingly recognized, especially following the discovery of various autoantibodies that target specific podocytic antigens and the promising treatment responses seen with B cell depleting therapies. The presence of autoreactive B cells and autoantibodies that bind to antigens on podocyte surfaces are characteristic features of MN, and are the result of breaches in central and peripheral tolerance of B lymphocytes. These perturbations in B cell tolerance include altered B lymphocyte subsets, dysregulation of genes that govern immunoglobulin production, aberrant somatic hypermutation and co-stimulatory signalling, abnormal expression of B cell-related cytokines, and increased B cell infiltrates and organized tertiary lymphoid structures within the kidneys. An understanding of the role of B cell tolerance and homeostasis may have important implications for patient management in MN, as conventional immunosuppressive treatments and novel B cell-targeted therapies show distinct effects on proliferation, differentiation and reconstitution in different B cell subsets. Circulating B lymphocytes and related cytokines may serve as potential biomarkers for treatment selection, monitoring of therapeutic response and prediction of disease relapse. These recent advances in the understanding of B cell tolerance in MN have provided greater insight into its immunopathogenesis and potential novel strategies for disease monitoring and treatment.

New-onset pediatric nephrotic syndrome following Pfizer-BioNTech SARS-CoV-2 vaccination: a case report and literature review

Various new vaccines against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have been rapidly developed. The new onset and recurrence of nephrotic syndrome triggered by some vaccines have been documented and several adult cases of minimal change nephrotic syndrome newly developing after SARS-CoV-2 vaccination have been reported. However, no reports of pediatric cases have been published. Indications for SARS-CoV-2 vaccines have been expanded to those as young as 12 years old and vaccination of children has just started in Japan. We encountered a 15-year-old boy without underlying disease who newly developed nephrotic syndrome after SARS-CoV-2 vaccination with BNT162b2 (Pfizer-BioNTech). He developed eyelid edema 4 days after vaccination and peripheral edema of the lower extremities a further 4 days later. Twenty-one days after vaccination, 60 mg of oral daily prednisolone was started. He achieved complete remission in 12 days without complications such as hypertension or acute kidney injury. We clinicians should be aware of the possibility of nephrotic syndrome developing after SARS-CoV-2 vaccination, not only in adults, but also in children.

Clinical and histological features in pediatric and adolescent/young adult patients with renal disease: a cross-sectional analysis of the Japan Renal Biopsy Registry (J-RBR)

BACKGROUND

Only a few studies have investigated epidemiological and clinicopathological information regarding pediatric and adolescent and young adult (AYA) patients with renal disease. The purpose of this study was to clarify the differences and relationship of clinicopathological findings between pediatric and AYA patients using the Japan Renal Biopsy Registry (J-RBR).

METHODS

This cross-sectional study analyzed data from patients registered in the J-RBR between 2007 and 2017. Clinicopathological findings at diagnosis were analyzed for 3,463 pediatric (age < 15 years) and 6,532 AYA (age 15-30 years) patients.

RESULTS

Although chronic nephritic syndrome was the most common clinical diagnosis at age > 5 years, nephrotic syndrome was the most frequent diagnosis at age < 4 years. The most common pathological diagnosis as classified by pathogenesis in pediatric patients was primary glomerular disease (except IgA nephropathy), whereas IgA nephropathy was increased in AYA patients. Mesangial proliferative glomerulonephritis was the most common pathological diagnosis as classified by histopathology in both pediatric and AYA patients. Minor glomerular abnormalities were the most frequent histopathologic diagnoses of nephrotic syndrome in childhood, but their frequency decreased with age.

CONCLUSION

To the best of our knowledge, this is the first report of clinicopathological features of pediatric and AYA patients in a large nationwide registry of renal biopsy. There were differences of clinical, pathological and histopathologic findings between pediatric and AYA patients.

Membranous nephropathy complicated by immune thrombocytopenia treated with low-density lipoprotein apheresis: a case report and literature review

Immune thrombocytopenia (ITP) may lead to membranous nephropathy (MN). Here, we report a case of MN complicated by ITP and validate the hypothesis that circulating antiplatelet antibodies cause MN using immunofluorescence analysis for immunoglobulin (Ig) G subclass and anti-phospholipase A2 receptor (PLA2R) antibodies. A 39-year-old Japanese man with ITP, who had been treated with prednisolone for 10 months, achieved a stable disease condition. However, 4 months after tapering the dose down to 10 mg prednisolone, he developed nephrotic syndrome, with a urinary protein-to-creatinine ratio (U-PCR) of 10.6 g/g Cr and was admitted to our hospital. His platelet count, at 89,000/μL, was lower than the normal range, indicating the recurrence of ITP. Renal biopsy revealed the thickening of the glomerular basement membrane with the deposition of IgG and complement component 3. Predominant deposition of IgG1 and negativity for anti-PLA2R staining indicated secondary MN; however, no typical conditions of secondary MN were evident. Although oral prednisolone and cyclosporine A were administered, he was refractory to treatment. A total of 12 sessions of low-density lipoprotein apheresis (LDL-A) decreased his U-PCR to < 3 g/g Cr. Seven months after discharge, his U-PCR further decreased to 0.54 g/g Cr and platelet count recovered to > 200,000/μL. Our literature review reveals that this condition is refractory to steroid therapy. LDL-A can be an effective treatment in drug-resistant MN complicated by ITP.

Characteristics and risk factors for Pneumocystis jirovecii pneumonia in patients with idiopathic membranous nephropathy

Pneumocystis jirovecii pneumonia (PCP) is a life-threatening opportunistic infection in idiopathic membranous nephropathy (IMN) patients, who are treated with immunosuppressive drugs. However, the risk factors of infection and their prognosis are rarely investigated. We aimed to characterize the clinical manifestations of PCP in patients with IMN, and to understand their risk factors, so that we can provide early warnings to patients with high risk and potential poor prognosis. We conducted a retrospective observational study of IMN patients in a referral center in China, from Jan 2012 to Dec 2018. Clinical and laboratory data were collected separately at the time of IMN and PCP diagnosis. Patients with PCP were matched to those without by gender and age at a ratio of 1:4. The risk factors and prognostic factors were determined by univariate and multivariate logistic regression analysis. A total of 879 patients with IMN were included, with a median follow-up of 267 (interquartile range (IQR) 64,842) days. In total, 26 (2.96%) of them were diagnosed with PCP. The infection rate increased to 3.87% among patients who received corticosteroids, and it further increased to 5.49% in those received over 0.5mg/kg prednisone. Univariate analysis indicated that initial usage of corticosteroids, use of cyclophosphamide, reduced estimated glomerular filtration rate (eGFR), and higher 24-h proteinuria were related to the PCP susceptibility. Multivariate analysis revealed that corticosteroid treatment and reduced eGFR increased the risk of the Pneumocystis jirovecii infection. The case fatality rate of the PCP patients was 23.08%, and increased to 75% among patients requiring invasive ventilation. Univariate analysis indicated that pulmonary insufficiency, invasive ventilation, decreased eGFR, and increased lactate dehydrogenase at presentation were linked to poor prognosis. PCP is not rare in patients with IMN, especially those on corticosteroids, and presented with decreased eGFR. Considering the high case fatality rate, further studies are in need for prevention and management of these patients.

Clinical manifestations of focal segmental glomerulosclerosis in Japan from the Japan Renal Biopsy Registry: age stratification and comparison with minimal change disease

Focal segmental glomerulosclerosis (FSGS) is a serious condition leading to kidney failure. We aimed to investigate the clinical characteristics of FSGS and its differences compared with minimal change disease (MCD) using cross-sectional data from the Japan Renal Biopsy Registry. In Analysis 1, primary FSGS (n = 996) were stratified by age into three groups: pediatric (< 18 years), adult (18–64 years), and elderly (≥ 65 years), and clinical characteristics were compared. Clinical diagnosis of nephrotic syndrome (NS) was given to 73.5% (97/132) of the pediatric, 41.2% (256/622) of the adult, and 65.7% (159/242) of the elderly group. In Analysis 2, primary FSGS (n = 306) and MCD (n = 1303) whose clinical diagnosis was nephrotic syndrome (NS) and laboratory data were consistent with NS, were enrolled. Logistic regression analysis was conducted to elucidate the variables which can distinguish FSGS from MCD. On multivariable analysis, higher systolic blood pressure, higher serum albumin, lower eGFR, and presence of hematuria associated with FSGS. In Japanese nationwide registry, primary FSGS patients aged 18–64 years showed lower rate of NS than those in other ages. Among primary nephrotic cases, FSGS showed distinct clinical features from MCD.

The revised version 2018 of the nationwide web-based registry system for kidney diseases in Japan: Japan Renal Biopsy Registry and Japan Kidney Disease Registry

Background

The Japan Renal Biopsy Registry (J-RBR), the first nation-wide registry of renal biopsies in Japan, was established in 2007, and expanded to include non-biopsy cases as the Japan Kidney Disease Registry (J-KDR) in 2009. The J-RBR/J-KDR is one of the biggest registries for kidney diseases. It has revealed the prevalence and distribution of kidney diseases in Japan. This registry system was meant to be revised after 10 years.

Methods

In 2017, the Committees of the Japanese Society of Nephrology started a project for the revision of the J-RBR/J-KDR. The revised system was designed in such a way that the diagnoses of the patients could be selected from the Diagnosis Panel, a list covering almost all known kidney diseases, and focusing on their pathogenesis rather than morphological classification. The Diagnosis Panel consists of 22 categories (18 glomerular, 1 tubulointerstitial, 1 congenital/genetical, 1 transplant related, and 1 other) and includes 123 diagnostic names. The items for clinical diagnosis and laboratory data were also renewed, with the addition of the information on immunosuppressive treatment.

Results

The revised version of J-RBR/J-KDR came into use in January 2018. The number of cases registered under the revised system was 2748 in the first year. The total number of cases has reached to 43,813 since 2007.

Conclusion

The revised version 2018 J-RBR/J-KDR system attempts to cover all kidney diseases by focusing on their pathogenesis. It will be a new platform for the standardized registration of kidney biopsy cases that provides more systemized data of higher quality.

Electronic supplementary material

The online version of this article (10.1007/s10157-020-01932-6) contains supplementary material, which is available to authorized users.

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

BACKGROUND

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

PATIENTS AND METHODS

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

RESULTS

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

CONCLUSION

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

A case of denosumab-associated membranous nephropathy in a patient with rheumatoid arthritis

We herein report a case of anti-RANKL monoclonal antibody-associated membranous nephropathy (MN). A 67-year-old woman with a history of rheumatoid arthritis treated with prednisolone and methotrexate for more than 30 years and osteoporosis treated with eldecalcitol and teriparatide for 4 years had achieved a stable disease condition. Her kidney function was normal and her urinalysis was negative for hematuria and proteinuria. An anti-RANKL monoclonal antibody (denosumab) was administered for the treatment of osteoporosis. Four months later, proteinuria appeared (2.3 g/g creatinine) and remained positive for about 6 months, therefore, she was admitted to our hospital. An immunofluorescence study revealed fine granular deposits of immunoglobulin G (IgG) and C3 along the capillary walls. Staining for IgG subclasses showed positive staining for IgG1 (3+), IgG2 (1+), IgG3 (1+), and IgG4 (1+); phospholipase A2 receptor was negative. Electron microscopy showed partial subepithelial and intramembranous deposits and focal thickening of the glomerular basement membrane. No evidence of malignancy or infectious disease was seen. After cessation of denosumab, the proteinuria gradually improved. Based on the renal biopsy results and clinical course (development of marked proteinuria in the presence of denosumab with subsequent amelioration in the absence of the drug), we diagnosed the patient with secondary MN due to denosumab. This is the first reported case of denosumab-associated MN.

The Usefulness of Phospholipase A2 Receptor and IgG4 Detection in Differentiation Primary Membranous Nephropathy From Secondary Membranous Nephropathy in Renal Biopsy

Membranous nephropathy (MGN) is the most common cause of the nephrotic syndrome in adults. Most cases of MGN are primary, but secondary MGN are frequently encountered. Determination of secondary MGN is crucial for initiation of appropriate treatment. The diagnostic performance of the phospholipase A2 receptor (PLA2R) and immunoglobulin G4 (IgG4) detection based on immunohistochemistry were evaluated using biopsy tissues of 59 primary and 56 secondary MGN cases for discrimination between primary MGN and secondary MGN. The PLA2R and IgG4 detection based on immunohistochemistry were dominantly positive in primary MGN cases. Sensitivity and specificity values for identification of primary MGN were 83% and 88% for PLA2R, and 76% and 86% for IgG4. Both PLA2R and IgG4 positivity showed a high specificity of 96.4% for identifying primary MGN. A meta-analysis was performed for analysis of the diagnostic accuracy of histologic PLA2R and IgG4 deposition for differentiation of primary from secondary MGN. The overall sensitivity, specificity, and area under curve of summary receiver operating characteristics were 76%, 86%, 0.93 for histologic PLA2R deposition, and 80%, 69%, 0.82 for histologic IgG4 deposition. PLA2R and IgG4 detection based on immunohistochemistry can be useful for differentiation of primary MGN from secondary MGN.

Clinical and Pathological Analysis of 4910 Patients Who Received Renal Biopsies at a Single Center in Northeast China

Purpose

To identify the epidemiology and pathological types of kidney diseases and their changes during the past decade, in a population from Northeast China.

Methods

We retrospectively analysed clinical and renal pathological data from 4910 patients who received renal biopsies in the Second Hospital of Jilin University from 2008 to 2017.

Results

Males received more renal biopsies than females (p < 0.001). The average age (p < 0.001) and percentage of elderly patients (p < 0.001) increased over time. The pathological types were primary glomerulonephritis (PGN, 73.2%), secondary glomerulonephritis (SGN, 23.7%), tubular-interstitial nephropathy (TIN, 2.8%), and hereditary nephropathy (HN, 0.3%). The most common forms of PGN were membranous nephropathy (MN, 37.2%) and IgA nephropathy (IgAN, 29.9%). Over time, the prevalence of IgAN decreased, but the prevalence of MN increased. MN was more common in middle-aged and elderly patients, but IgAN was most common in young adults. Analysis of SGN data indicated that lupus nephritis (LN, 34.0%), Henoch-Schönlein purpura glomerulonephritis (HSPN, 17.9%), and diabetic nephropathy (DN, 11.7%) were the most common forms. Over time, the prevalence of DN (p = 0.003), hypertension-associated renal damage (p = 0.005), and systemic vasculitis-associated nephritis (SVARD, p < 0.001) increased, but the prevalence of HSPN (p < 0.001) and hepatitis B virus-associated glomerulonephritis (HBV-GN, p = 0.001) decreased. Nephrotic syndrome was the main clinical manifestation of PGN.

Conclusion

From 2008 to 2017, renal biopsies were increasingly performed in the elderly. There were notable changes in the epidemiology and pathological types of kidney disease among renal biopsy patients at our centre.

Case report: Gastric cancer-associated membranous nephropathy that recurred after complete remission and formation of peritoneal dissemination

Membranous nephropathy associated with malignant neoplasm may remit completely with treatment of the underlying disease. In such cases, recurrence is very rare. However, after a recurrence, attention should be paid to the possible recurrence of the underlying disease.

Acute arterial cardiovascular events risk in patients with primary membranous nephropathy

BACKGROUND

Venous thromboembolism is a well established risk in patients with primary membranous nephropathy (MN) due to deficiency in natural anti-coagulants. Recent studies suggested a higher risk of arterial thrombotic events as well in this group.

AIM

To identify that risk in our cohort.

METHODS

We reviewed the data of all patients who had biopsy proven primary MN at our institute between 2003 and 2013. Clinical data were retrospectively reviewed until November 2016. The cardiovascular (CV) events, including acute coronary syndromes and strokes were determined and included only if occurred after the diagnosis of the nephropathy.

RESULTS

A total of 204 patients had biopsy proven MN. Follow up information was available for 166 patients. Thirty-one patients (18.6%) developed CV events during follow up. Thirty-eight per cent of total events occurred within 1 year of MN diagnosis. Forty-two per cent of those who developed CV events were not on anti-thrombotic medications and 60% were not on statin therapy. Male gender, age, diabetes and absence of statins therapy were associated with higher rates of CV events in this group.

CONCLUSION

There is an increased risk of arterial events in patients with primary MN. This risk is greatest in the first year of diagnosis. The risk should be highlighted in this group of patients and anti-platelets and statin therapy should be considered especially during the initial phase of the disease.

Treatment patterns and steroid dose for adult minimal change disease relapses: A retrospective cohort study

Background

In patients with adult minimal change disease (MCD), proteinuria relapse is a problem to solve. However, the optimal relapse treatment regimen remains unclear regarding steroid dose. We described the treatment pattern of adult MCD patients and evaluated the appropriate steroid dose for relapse treatment.

Methods

This retrospective multicenter cohort study included 192 patients with adult biopsy-proven MCD from 14 hospitals in Japan. The prescription pattern of immunosuppressive drugs in relapse was reviewed. To assess the association between steroid dose used for relapse and subsequent outcomes, data of patients with tapered prednisolone (PSL) dosage to <10 mg/day before the first relapse in whom the dose was subsequently increased to ≥10 mg/day were extracted and assigned to the High-PSL or Low-PSL groups, based on the median dose of 20 mg/day. Multivariate Cox proportional hazard model and propensity score analysis with multiple imputations were conducted to compare their clinical course.

Results

During a median observation period of 37.6 months, 186/192 (96.9%) patients achieved complete remission (CR) and 100 (52.1%) relapsed. The median urinary protein level at the first relapse was 3.12 g/gCr or g/day. The proportion of non-steroidal immunosuppressant use increased with relapses; cyclosporine was the most common. No significant differences were found in the second relapse, frequent relapses, or adverse events between High-PSL (n = 34) and Low-PSL (n = 36) groups. A multivariate Cox proportional hazard model revealed that the hazard ratios adjusted with propensity score for the second relapse were 0.94 (High-PSL vs. Low-PSL; 95% confidence interval, 0.42–2.10; P = 0.88) and 0.82 (PSL dose per 10 mg/day; 95% confidence interval, 0.58–1.16; P = 0.25).

Conclusions

Among patients in CR with PSL dose <10 mg/day, higher steroid dose (PSL >20 mg/day) was not associated with favorable outcomes after the first relapse as compared to lower dose (10–20 mg/day).

Regional variations in immunosuppressive therapy in patients with primary nephrotic syndrome: the Japan nephrotic syndrome cohort study

BACKGROUND

The lack of high-quality clinical evidences hindered broad consensus on optimal therapies for primary nephrotic syndromes. The aim of the present study was to compare prevalence of immunosuppressive drug use in patients with primary nephrotic syndrome across 6 regions in Japan.

METHODS

Between 2009 and 2010, 380 patients with primary nephrotic syndrome in 56 hospitals were enrolled in a prospective cohort study [Japan Nephrotic Syndrome Cohort Study (JNSCS)], including 141, 151, and 38 adult patients with minimal change disease (MCD), membranous nephropathy (MN), and focal segmental glomerulosclerosis (FSGS), respectively. Their clinical characteristics were compared with those of patients registered in a large nationwide registry of kidney biopsies [Japan Renal Biopsy Registry (J-RBR)]. The regional prevalence of use of each immunosuppressive drug was assessed among adult MCD, MN, and FSGS patients who underwent immunosuppressive therapy in the JNSCS (n = 139, 127, and 34, respectively). Predictors of its use were identified using multivariable-adjusted logistic regression models.

RESULTS

The clinical characteristics of JNSCS patients were comparable to those of J-RBR patients, suggesting that the JNSCS included the representatives in the J-RBR. The secondary major immunosuppressive drugs were intravenous methylprednisolone [n = 33 (24.6%), 24 (19.7%), and 9 (28.1%) in MCD, MN, and FSGS, respectively] and cyclosporine [n = 25 (18.7%), 62 (50.8%), and 16 (50.0%), respectively]. The region was identified as a significant predictor of use of intravenous methylprednisolone in MCD and MN patients.

CONCLUSION

Use of intravenous methylprednisolone for MCD and MN differed geographically in Japan. Its efficacy should be further evaluated in a well-designed trial.

Growth Differentiation Factor-15 as a Predictor of Idiopathic Membranous Nephropathy Progression: A Retrospective Study

Idiopathic membranous nephropathy (IMN) is a major cause of nephrotic syndrome. No biomarker to predict the long-term prognosis of IMN is currently available. Growth differentiation factor-15 (GDF-15) is a member of the transforming growth factor-β superfamily and has been associated with chronic inflammatory disease. It has the potential to be a useful prognostic marker in patients with renal diseases, such as diabetic nephropathy and IgA nephropathy. This study examined whether GDF-15 is associated with the clinical parameters in IMN and showed that GDF-15 can predict IMN disease progression. A total of 35 patients with biopsy-proven IMN, treated at Chungnam National University Hospital from January 2010 to December 2015, were included. Patients younger than 18 years, those with secondary membranous nephropathy, and those lost to follow-up before 12 months were excluded. Levels of GDF-15 at the time of biopsy were measured using enzyme-linked immunosorbent assays. Disease progression was defined as a ≥30% decline in estimated glomerular filtration rate (eGFR) or the development of end-stage renal disease. The mean follow-up was 44.1 months (range: 16–72 months). Using receiver operating curve analysis, the best serum GDF-15 cut-off value for predicting disease progression was 2.15 ng/ml (sensitivity: 75.0%, specificity: 82.1%, p = 0.007). GDF-15 was significantly related to age and initial renal function. In the Kaplan-Meier analysis, the risk of disease progression increased in patients with GDF-15 ≥ 2.15 ng/ml when compared with those with GDF-15 < 2.15 ng/ml (50.0% versus 9.7%) (p = 0.012). In the multivariate Cox regression analysis adjusted for potential confounders, only GDF-15 was significantly associated with disease progression in IMN (p = 0.032). In conclusion, the GDF-15 level at the time of diagnosis has a significant negative correlation with initial renal function and is associated with a poor prognosis in IMN. Our results suggest that GDF-15 provides useful prognostic information in patients with IMN.

Membranous nephropathy associated with pregnancy: an anti-phospholipase A2 receptor antibody-positive case report

Pregnancy and membranous nephropathy (MN) can occur concurrently with nephrotic syndrome. However, the pathophysiology of MN associated with pregnancy remains unclear, including the involvement of anti-M-type phospholipase A2 receptor (PLA2R) antibody, the major antigen of idiopathic MN (iMN). A treatment for the condition is also not established. We present the case of a 43-year-old pregnant female with incidental proteinuria and hypoalbuminemia. We made a diagnosis of nephrotic syndrome at 11 week gestation. Renal biopsy revealed iMN using predominant granular staining of IgG4 along the glomerular basement membrane. No secondary cause was identified. Oral glucocorticoid therapy was started from 17 week gestation and induced complete remission at 28 week gestation. A healthy infant was born at 38 week gestation. Glucocorticoid therapy was stopped postpartum without MN relapse. Anti-PLA2R antibody was later found to be positive using serum reserved from before treatment. In conclusion, we presented the case of a pregnant woman with iMN and anti-PLA2R antibodies, whose nephrotic syndrome was successfully controlled with oral glucocorticoids to reach complete remission, even after tapering off the medication. Pregnancy per se might be associated with iMN onset.

Clinical features and pathogenesis of membranoproliferative glomerulonephritis: a nationwide analysis of the Japan renal biopsy registry from 2007 to 2015

BACKGROUND

The incidence and age distribution of membranoproliferative glomerulonephritis (MPGN) vary throughout the world by race and ethnicity. We sought to evaluate the clinical features, pathogenesis, and age distribution of MPGN among a large nationwide data from the Japan Renal Biopsy Registry (J-RBR).

METHODS

A cross-sectional survey of 593 patients with MPGN (types I and III) registered in the J-RBR between 2007 and 2015 was conducted. Clinical parameters, and laboratory findings at diagnosis were compared between children (< 20 years), adults (20-64 years), and elderly patients (≥ 65 years).

RESULTS

The median age of the patients was 59.0 years and mean proteinuria was 3.7 g/day. The rate of nephrotic syndrome was significantly higher in adults (40.4%) and elderly patients (54.0%) than in children (14.9%), whereas the rate of chronic glomerulonephritis was significantly higher in children (66.2%) than in adults (34.4%) and elderly patients (31.2%). According to the CGA risk classification, high-risk (red zone) cases accounted for 3.4% of children, 52.5% of adults and 84.1% of elderly patients with MPGN. As for pathogenesis, primary MPGN was most frequent (56.0%). Lupus nephritis was the most common disease among adult patients with secondary MPGN, whereas infectious disease was more common in elderly patients. Multiple regression analysis revealed that high systolic blood pressure and high proteinuria were independent factors associated with decreased estimated glomerular filtration rate (eGFR) in adults and elderly patients with MPGN.

CONCLUSIONS

In Japan, adults and elderly patients with MPGN had a lower eGFR and severer proteinuria than children.

[Membranous nephropathy in a Russian population]

AIM

To analyze the clinical and morphological manifestations of membranous nephropathy (MN) and to evaluate the efficiency of its therapy.

MATERIAL AND METHODS

MN cases in 2009 to 2016 were retrospectively detected with a subsequent analysis of patients with primary MN (PMN). The titer of IgG-autoantibodies to phospholipase A2 receptor (anti-PLA2R Ab) was determined by an indirect immunofluorescence assay. Treatment outcomes, such as the time course of changes in proteinuria, nephrotic syndrome (NS), and the development of complete and partial remissions (CR and PR), were assessed.

RESULTS

MN was detected in 201 cases; the secondary etiology of the disease was established in 24.9%. The prevalence of MN among morphologically confirmed glomerulopathies was 14%; that of PMN was 10.4%. The median period to diagnosis PMN was 8 (5; 19) months. 150 patients with PMN (66.7% were men; age was 50±15 years) were distributed according to the following morphological stages: Stages I (23.9%), II (48.5%), III (26.1%), and IV (1.5%). Elevated anti-PLA2R Ab levels were found in 51.6% of cases; NS in the presence of proteinuria was detected in 85.6% of patients. An estimated glomerular filtration rate (eGFR) of <60 ml/min/1.73 m2 was seen in 25% of cases. Treatment outcomes were evaluated in 80 cases; the median follow-up period was 19 (8; 40) months. 68% of cases had CR (32%) or PR (36%) with a median follow-up of 26 (13; 44) months. Spontaneous CRs or PRs were observed in 7.5% of the patients. Multivariate analysis showed that the probability of CR or PR increased 3.2-fold in the use of cyclophosphamide and/or cyclosporine and decreased as eGFR dropped.

CONCLUSION

In Russia, PMN is a common type of glomerulopathy, the specific features of which should include the low rates of spontaneous remissions and detection of anti-PLA2R Abs. For renal protection, the majority of patients with PMN require timely diagnosis and treatment; individualization of the choice of treatment and its enhanced efficiency call for further investigations.

Cost-Effectiveness of Administering Rituximab for Steroid-Dependent Nephrotic Syndrome and Frequently Relapsing Nephrotic Syndrome: A Preliminary Study in Japan

With regard to the use of rituximab for patients with steroid-dependent nephrotic syndrome and frequently relapsing nephrotic syndrome, not only has the regimen not been clinically verified but also there is a lack of health economics evidence. Therefore, we conducted a prospective clinical study on 30 patients before (with steroids and immunosuppressants) and after introducing rituximab therapy. Relapse rates and total invoiced medical expenses were selected as the primary endpoints for treatment effectiveness and treatment costs, respectively. As secondary endpoints, cost-effectiveness was compared before and after administering rituximab in relation to previous pharmacotherapy. The observation period was 24 months before and after the initiation of rituximab. We showed that there was a statistically significant improvement in the relapse rate from a mean of 4.30 events before administration to a mean of 0.27 events after administration and that there was a significantly better prognosis in the cumulative avoidance of relapse rate by Kaplan-Meier analysis (p < 0.01). Finally, the total medical costs decreased from 2,923 USD to 1,280 USD per month, and the pre-post cost-effectiveness was confirmed as dominant. We, therefore, conclude that treatment with rituximab was possibly superior to previous pharmacological treatments from a health economics perspective.

Membranous Nephropathy with an Enhanced Granular Expression of Thrombospondin Type-1 Domain-containing 7A in a Pregnant Woman

A 30-year-old woman with proteinuria first noted at 26 weeks of gestation was admitted to undergo further evaluation. A renal biopsy revealed membranous nephropathy (MN). There was no evidence of any secondary MN. Prednisolone was initiated 6 months after delivery. Four months later, her urine protein became negative. Enhanced granular staining for thrombospondin type-1 domain-containing 7A (THSD7A) in the glomeruli was retrospectively detected in a biopsy specimen. A literature review revealed that 60% of cases of THSD7A-related MN occurred in women of childbearing age. Therefore, THSD7A-related MN should be considered in female patients presenting with idiopathic MN in childbearing age.

Drug-induced kidney disease: a study of the Japan Renal Biopsy Registry from 2007 to 2015

Introduction

The Japan Renal Biopsy Registry (J-RBR) was started in 2007 by the Committee for the Standardization of Renal Pathological Diagnosis and the Committee for the Kidney Disease Registry of the Japanese Society of Nephrology. The purpose of this report is to clarify drug-induced kidney disease (DIKD) of renal biopsied cases in Japan.

Subjects and methods

We analyzed the data of 26,535 cases that were registered in the J-RBR from 2007 to 2015.

Results

Based on clinical and pathological diagnoses, 328 cases (176 males and 152 females) of renal biopsy-proven DIKD were registered in the J-RBR from 2007 to 2015 (1.24 % of all cases). The frequency of DIKD increased with age. The number of cases peaked in the 6th–8th decade in all pathological categories, except for the number of chronic tubulointerstitial lesions (CTIL), which peaked in the 4th–5th decade. Overall, the frequency of DIKD was 3 times higher in the 7th decade than in the 2nd decade (1.86 vs. 0.62 %). The main clinical diagnoses were DIKD in 150 cases (45.7 %), nephrotic syndrome in 66 cases (20.1 %), chronic nephritic syndrome in 55 cases (16.8 %), and rapidly progressive glomerulonephritis in 30 cases (9.1 %). DIKD was registered as a secondary diagnosis in 136 cases (41.5 %). The pathological findings of these cases were glomerular lesions in 105 cases (32.0 %), acute tubulointerstitial lesions (ATIL) in 87 cases (26.5 %), CTIL in 72 cases (22.0 %), and sclerotic glomerular lesions and/or nephrosclerosis in 18 cases (5.5 %). ATIL and CTIL were mainly found in cases in which DIKD was diagnosed on the basis of the patient’s clinical findings. In addition, nephrotic syndrome-related membranous nephropathy (MN) was the major cause of renal damage in 59.4 % of the cases involving glomerular injuries. According to the CGA risk classification, high-risk (red zone) cases accounted for 56.1 % of all cases of DIKD and 75.9, 64.9, and 33.3 % of the cases involving ATIL, CTIL, and glomerular injuries, respectively. The causative drugs were identified in 102 cases, including bucillamine in 38 cases of MN, gemcitabine in 3 cases of thrombotic microangiopathy, and other anticancer drugs in 14 cases (anti-vascular endothelial growth factor drugs in 3 cases and propyl thiouracil in 3 cases of anti-neutrophil cytoplasmic antibody-related nephritis).

Conclusion

Our analysis of the J-RBR revealed that DIKD mainly affects elderly people in Japan. ATIL or CTIL were found in approximately half of the biopsied cases of DIKD, and one-third involved glomerular lesions, mainly MN or clinical nephrotic syndrome.

Electronic supplementary material

The online version of this article (doi:10.1007/s10157-015-1201-4) contains supplementary material, which is available to authorized users.

Management of Membranous Nephropathy in Asia

BACKGROUND

Membranous nephropathy (MN) is the most common cause of nephrotic syndrome (NS) in adults, accounting for about 20.0% of all NS cases. With an increasing prevalence, especially in the elderly, it has received great attention in Asia.

SUMMARY

Recently, the prevalence of idiopathic MN (IMN) has significantly increased among the elderly people in Asia and other places in the world. Although the exact mechanism of IMN remains unveiled, the identification of new antigens such as PLA2R and THSD7A has greatly enhanced our understanding of its pathogenesis. However, consensus has not yet been reached for the treatment of IMN in Asia. For example, there are many choices of immunosuppressive agents, including corticosteroid monotherapy, corticosteroids combined with cytotoxic agents [such as alkylating agents, calcineurin inhibitors or mycophenolate mofetil (MMF)] or traditional Chinese medicine (triptolide, Shenqi and other Chinese herbal soups). Patients with IMN in Asia often have a favorable prognosis, and progression to end-stage renal disease is relatively uncommon compared to other populations.

KEY MESSAGES

The prevalence of MN has significantly increased in the last years. The treatment strategies for IMN have not reached consensus in Asia. Traditional Chinese medicine is generally preferred by the Chinese, and compelling results have been reported recently.

FACTS FROM EAST AND WEST

(1) The prevalence of IMN is increasing worldwide, particularly in elderly patients, and has been reported in 20.0-36.8% of adult-onset NS cases. The presence of anti-PLA2R antibodies in serum or PLA2R on renal biopsy is the most predictive feature for the diagnosis of IMN and is used in both the East and West; however, appropriate screening to rule out secondary causes should still be performed. (2) Several observational (nonrandomized) Asian studies indicate a good response to corticosteroids alone in IMN patients, although no randomized controlled trials have been done in Asian membranous patients at high risk of progression. Corticosteroid monotherapy has failed in randomized controlled trial studies in Western countries and is therefore not recommended. (3) Cyclophosphamide is the most commonly prescribed alkylating agent in Europe and China. Also, chlorambucil is still used in some Western countries, particularly in Europe. In North America, calcineurin inhibitors are the more common first-line treatment. (4) Cyclosporine is predominantly used as monotherapy in North America, although KDIGO (Kidney Disease: Improving Global Outcomes) and Japanese guidelines still recommend a combination with low-dose corticosteroids. Clinical studies both in Asia and Europe showed no or little effects of monotherapy with MMF compared to standard therapies. (5) There are encouraging data from nonrandomized Western studies for the use of rituximab and a few small studies using adrenocorticotropic hormone. Clinical trials are ongoing in North America to confirm these observations. These drugs are rarely used in Asia. (6) A Chinese study reported that 36% of IMN patients suffered from venous thromboembolism versus 7.3% in a North American study. Prophylactic anticoagulation therapy is usually added to IMN patients with a low risk of bleeding in both Eastern and Western countries. (7) The Chinese traditional medicine herb triptolide, which might have podocyte-protective properties, is used in China to treat IMN. An open-label, multicenter, randomized controlled trial showed that Shenqi, a mixture of 13 herbs, was superior to corticosteroids plus cyclophosphamide therapy to restore epidermal growth factor receptor in IMN patients, although proteinuria improvement was equal in the two groups. Importantly, Shenqi treatment induced no severe adverse events while standard therapy did.

Successful treatment with s-1 and oxaliplatin combination therapy in an elderly patient with metastatic colorectal cancer initially presenting with membranous nephropathy

The incidence, morbidity, and mortality of colorectal cancer are increasing, largely owing to an increasingly aging population. Additionally, along with the increasing age of cancer patients, the number of patients with various comorbidities such as membranous nephropathy is also rising, and problems associated with the administration of chemotherapy to elderly patients with these conditions are becoming more common. Herein, we describe a case involving an 80-year-old woman who presented with general malaise, edematous limbs, and pleural effusion. An abdominal CT revealed multiple, relatively large, metastatic lesions in a wide area of the liver and left pleural effusion, and she was accordingly diagnosed with membranous nephropathy secondary to ascending colon cancer and multiple liver metastases. Despite her advanced age and the presence of membranous nephropathy, her general condition was favorable and chemotherapy was hence administered. Taking the toxicity profiles and the patient's preference into consideration, S-1 and oxaliplatin (SOX) therapy was selected, which showed a good tolerability. An abdominal CT after 8 cycles of SOX therapy revealed a marked reduction in the metastatic lesions in the liver and a decrease in the left pleural effusion, and the levels of tumor markers also decreased (partial response). At the latest follow-up, after the completion of 16 cycles, the condition of the patient remained stable, without any apparent signs of progressive disease. Based on this case, we conclude that, even for elderly patients with systemic complications or comorbid diseases, standard treatments should be considered after their general conditions, and therapeutic regimens have been sufficiently examined.

Study of mizoribine therapy in elderly patients with membranous nephropathy: comparison with patients not receiving mizoribine

BACKGROUND

We have previously reported the results of mizoribine (MZR) treatment for elderly patients with membranous nephropathy (MN). Here, we retrospectively compared these patients with those who had been initially treated with prednisolone (PSL) alone.

METHODS

The subjects were patients with MN aged ≥65 years who were examined between April 2007 and September 2010 and followed for at least 1 year.

RESULTS

The median period until the start of treatment in the MZR group (MZR-G) was 60 days. The urinary protein level at the start of MZR treatment was 3.89±2.3 g/gCr. Urinary protein in the group not treated with MZR (N-MZR-G) was 1.0±1.1 g/gCr, showing a tendency to improve in patients with nephrotic syndrome relative to the MZR-G (p=0.055). The PSL dose in the MZR-G versus N-MZR-G at 1 year was 5.7±3.0 versus 6.25±2.5 mg/day, the urinary protein level was 0.19±0.2 versus 0.13±0.1 g/gCr, and the remission rate was 80 versus 75%. In the MZR-G, the total PSL dose at 1 year after the start of MZR treatment was 5,058±1,904 versus 6,649±875 mg in the N-MZR-G. Adverse events occurred in 3/5 patients (60%) in the MZR-G and in 3/4 patients (75%) in the N-MZR-G.

CONCLUSION

Elderly patients with MN who respond poorly to PSL treatment may be treated successfully with MZR.

Circulating TNF receptors are significant prognostic biomarkers for idiopathic membranous nephropathy

Idiopathic membranous nephropathy (iMN) is a common cause of nephrotic syndrome in adults. A biomarker to accurately indicate the severity of iMN and predict long-term prognosis is insufficient. Here, we evaluated the clinical significance of circulating tumor necrosis factor receptors (cTNFRs) as prognostic biomarkers of iMN with nephrotic syndrome. A total of 113 patients with biopsy-proven iMN and 43 healthy volunteers were enrolled in this study. Ninety patients with iMN had nephrotic range proteinuria. Levels of cTNFRs were measured by using serum samples collected at the time of initial diagnosis. Levels of cTNFRs were higher in the patients with nephrotic syndrome than in those with subnephrotic range proteinuria or in the healthy volunteers (P for trend <0.001). Estimated glomerular filtration rate and proteinuria tended to worsen as the cTNFRs levels increased. Having a cTNFR1 level within the highest tertile was a significant risk factor for renal progression after adjustment, in comparison with the other tertiles (hazard ratio [HR], 3.39; 95% confidence interval [95% CI], 1.48-7.78; P = 0.004). The cTNFR2 level within the highest tertile also significantly increased the risk of renal progression (HR, 3.29; 95% CI, 1.43-7.54; P = 0.005). Renal tubular TNFRs expression was associated with cTNFRs level. However, the cTNFRs levels were not associated with autoantibody against phospholipase A2 receptor reactivity/levels or treatment response. This study demonstrated that cTNFRs levels at the time of initial diagnosis could predict renal progression in patients with iMN.

Comparison of methylprednisolone plus prednisolone with prednisolone alone as initial treatment in adult-onset minimal change disease: a retrospective cohort study

BACKGROUND AND OBJECTIVES

Previous studies suggested that intravenous methylprednisolone possibly accelerates remission of proteinuria in adult-onset minimal change disease; its impact on relapse of proteinuria is unknown.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This multicenter retrospective cohort study included 125 adult-onset minimal change disease patients diagnosed by kidney biopsy between 2000 and 2009 and treated initially with corticosteroid in five nephrology centers in Japan participating in the Study of Outcomes and Practice Patterns of Minimal Change Disease. Times to first remission and first relapse of proteinuria after initiating the first immunosuppressive therapy were compared between 65 patients with initial use of intravenous methylprednisolone followed by prednisolone and 60 patients with initial use of prednisolone alone using multivariate Cox proportional hazards models. After calculating the probability of receiving methylprednisolone and prednisolone using a logistic regression model (propensity score), the results were ascertained using propensity score-matched and -stratified models.

RESULTS

During the median 3.6 years of observation (interquartile range=2.0-6.9), all 65 patients in the methylprednisolone and prednisolone group achieved remission within 11 (8-20) days of the corticosteroid initiation, whereas in the prednisolone group, 58 of 60 patients (96.7%) achieved remission within 19 (12-37) days (P<0.001). After achieving first remission, 32 (49.2%) patients in the methylprednisolone and prednisolone group and 43 (74.1%) patients in the prednisolone group developed at least one relapse. Multivariate Cox proportional hazards models revealed that methylprednisolone and prednisolone use was significantly associated with early remission (multivariate-adjusted hazard ratio, 1.56; 95% confidence interval, 1.06 to 2.30) and lower incidence of relapse (0.50; 95% confidence interval, 0.29 to 0.85) compared with prednisolone use alone. These results were ascertained in propensity score-based models. No significant difference was observed in incidence of adverse events, including infection, aseptic osteonecrosis, cataract, diabetes, and gastrointestinal bleeding.

CONCLUSIONS

Initial use of methylprednisolone was associated with earlier remission and lower incidence of relapse in adult-onset minimal change disease patients. Efficacy of methylprednisolone should be evaluated in randomized controlled trials.

Pathological patterns of primary nephrotic syndrome in Central China: a retrospective study of 627 cases

BACKGROUND

The pathological patterns underlying PNS in adult are poorly studied in Central China.

METHODS

This is a retrospective analysis of the clinical and pathologic data involving 627 adult patients with PNS who have been finished the renal biopsies from January 2009 to September 2012 in XiangYa 2nd Hospital of Central South University. Patients enrolled in our study were all from Central China.

RESULTS

There were 379 males and 248 females, formed the ratio of 1.53:1. There existed three main sorts of pathological patterns underlying PNS: membranous nephropathy (MN) 26.63%, minimal change disease (MCD) 23.60%, IgA nephropathy (IgAN) 23.39%. Among all biopsies, the proportion of FSGS underlying PNS increased from 5.8% during the period from 2009 to 2010 to 14.7% during the period from 2011 to 2012. The most common complication of PNS was infectious diseases, and MCD underlying PNS ran a higher risk of encountering acute renal injury. IgAN had the highest incidence of hematuresis. The common pathological patterns of PNS differed in age-brackets: IgAN and MCD were the main pathological lesions in patients aged from 16 to 30 years; MN mostly occurs in patients over 30. MCD was the dominating pathological lesions underlying IgAN which expressed as PNS.

CONCLUSIONS

(1) MN was the most frequent pathological pattern underlying PNS, the proportion of FSGS underlying PNS increased during the last 2 years. (2) The common pathological patterns of PNS differed in age-brackets and pathological patterns correlated to the complications or comorbidities of PNS to some extent.