Nephrotic syndrome with rectus sheath hematoma: a case report.

BACKGROUND: Rectus sheath hematoma is a rare presentation often associated with abdominal trauma and anticoagulant therapy. Here, we present a patient with severe rectus sheath hematoma accompanied by nephrotic syndrome who achieved significant clinical improvement without the need for invasive treatment. CASE PRESENTATION: A 72-year-old Japanese woman was referred to our hospital for the treatment of nephrotic syndrome. She was receiving steroid and anticoagulant therapy. Then she had abdominal pain and she was diagnosed with spontaneous rectus sheath hematoma by abdominal computed tomography. She received transfusion and was managed conservatively with bed rest, which led to improvement in abdominal pain. CONCLUSION: Despite the absence of trauma history, rectus sheath hematoma should be considered in patients at risk of vascular failure, including those receiving anticoagulant or steroid therapy, those who are elderly, and those with nephrotic syndrome.

Trajectory of GFR Decline and Fluctuation in Albuminuria Leading to End-Stage Kidney Disease in Patients With Biopsy-Confirmed Diabetic Kidney Disease.

Introduction: Data on longitudinal trajectory of kidney function decline and fluctuation in albuminuria leading to end-stage kidney disease (ESKD) is sparse in patients with type 2 diabetes. Methods: Using data from an observational study of patients with type 2 diabetes and biopsy-confirmed diabetic kidney disease (DKD), generalized additive mixed models (GAMMs) were performed to quantify patterns of longitudinal trajectory of estimated glomerular filtration rate (eGFR) decline to ESKD associated with repeated measures of urine albumin-to-creatinine ratio (ACR). Results: Over a median follow-up period of 3.3 years, 155 of 319 patients progressed to ESKD. Among these patients, 91.6% exhibited a curvilinear pattern in their eGFR trajectory. The median coefficient of variation for ACR, representing the variability in ACR measurements, was 48.9 (interquartile range: 36.9, 68.2). The median compound annual growth rate (CAGR) for ACR, reflecting the variation in ACR progression over time, was 43.6% (interquartile range: 0.0, 102.5); and 84.5% of patients developed nephrotic-range albuminuria, with a majority remaining nephrotic and subsequently progressing to ESKD. There was a positive association between the instantaneous speed of eGFR decline and ACR. Conclusion: The observed curvilinear pattern in eGFR trajectory, high variability in ACR progression over time, and positive correlation between the speed of eGFR decline and ACR highlight the complex dynamics of disease progression and emphasize close monitoring of ACR fluctuation over time in patients with DKD.

Survey of Japanese nephrologists' use of clinical practice guidelines for rapidly progressive glomerulonephritis.

BACKGROUND: The guidelines in Japan for the treatment of rapidly progressive glomerulonephritis (RPGN) have been revised; the latest update was released in 2020. We investigated the actual usage of the new guidelines in Japan. METHODS: We distributed a survey electronically to board-certified nephrologists throughout Japan from December 15, 2021 to January 31, 2022. The survey focused on anti-neutrophil cytoplasmic antibody (ANCA)-associated RPGN and anti-glomerular basement membrane (GBM)-antibody RPGN, plus the treatment strategies and infection-prevention measures used. RESULTS: The survey was completed by 155 certified nephrologists from medical facilities across Japan. Their responses regarding treatment procedures revealed that ANCA-associated RPGN was treated with immunosuppressants and/or biologics by 58.1% of the survey respondents, and with plasma exchange (PE) in combination with corticosteroids by 21.3%. Regarding anti-GBM-antibody RPGN, 78.1% of the respondents used corticosteroids in combination with PE (63.2%), cyclophosphamide (CY) (23.9%), or rituximab (RTX) (8.4%), suggesting a discrepancy between clinical practice and the actual use of the guidelines. Trimethoprim-sulfamethoxazole was prescribed as prophylaxis by 94.8% of the respondents, reflecting the widespread recognition of the need to prevent infectious disease in patients with RPGN. CONCLUSIONS: The survey responses revealed how Japan's new RPGN guidelines are used in actual clinical practice. Our findings will contribute to the guidelines' dissemination and implementation.

Case report of systemic sclerosis: Uncommon manifestation of nephrotic syndrome post-renal crisis.

Kidney involvement in systemic sclerosis occurs in about 20% of cases, with scleroderma renal crisis as a significant complication. However, cases of glomerular disease with massive proteinuria are rare. We present a unique case of systemic sclerosis with the development of nephrotic syndrome. The report provides clinical details and podocyte pathological findings. A 40-year-old male with prior skin sclerosis was diagnosed with systemic sclerosis. Treatment with oral prednisone led to gradual improvement, but a year later, he experienced a systemic sclerosis renal crisis. Using the angiotensin converting enzyme (ACE) inhibitors improved kidney function. However, 3 months later, nephrotic syndrome was diagnosed. Despite an increased prednisolone dose, proteinuria persisted. A kidney biopsy revealed glomerular sclerosis and characteristic vascular changes. Immunofluorescent studies showed no deposits. Electron microscopy confirmed podocyte abnormalities.

Demographics and treatment of patients with primary nephrotic syndrome in Japan using a national registry of clinical personal records.

The nationwide clinical features of Japanese patients with primary nephrotic syndrome (NS), including minimal change disease (MCD), focal segmental glomerulosclerosis (FSGS), or membranous nephropathy (MN), have not yet been reported. We collected the clinical personal records of patients with primary NS between 2015 and 2018 from the national registry organized by the Japanese Ministry of Health, Labour, and Welfare. Overall, the demographics, chronic kidney disease classification based on glomerular filtration rate and albuminuria, and treatment of 6036 patients were collected: 3394 (56.2%) with MCD, 677 (11.2%) with FSGS, 1455 (24.1%) with MN, and 510 (8.5%) with others. MN patients were older than MCD and FSGS patients (67 vs. 42 and 47 years, respectively). Steroid-dependent NS or frequently relapsing NS was found in 70.2%, 40.5%, and 24.6%, whereas steroid-resistant NS was found in 6.4%, 36.0%, and 37.9% of patients in the MCD, FSGS, and MN, respectively. The present oral prednisolone use (mean dose, mg/day) was 87.2% (21.2), 80.9% (20.0), and 77.5% (18.8) of patients in the MCD, FSGS, and MN, respectively. The national registry of clinical personal records of primary NS could provide an informative insight into the characteristics, clinical features, and treatment approaches for patients with primary NS in Japan.

Polar vasculosis is associated with better kidney outcome in type 2 diabetes with biopsy-proven diabetic kidney disease: A multicenter cohort study.

AIMS/INTRODUCTION: This multicenter cohort study retrospectively assessed the association between polar vasculosis and the progression of diabetic kidney disease (DKD) in type 2 diabetes. MATERIALS AND METHODS: We enrolled 811 patients with type 2 diabetes, biopsy-proven DKD, and proteinuria (≥0.15 g/g creatinine [g/day]). The association between polar vasculosis and other kidney lesions was explored. The outcome was DKD progression defined as a composite of renal replacement therapy initiation or 50% decline in estimated glomerular filtration rate (eGFR) from baseline. RESULTS: Of the 811 cases, 677 (83.5%) had polar vasculosis. In multivariate logistic regression analysis, subendothelial widening of the glomerular basement membrane, glomerulomegaly, glomerular class in the Renal Pathology Society classification ≥IIb, vascular lesions, age, eGFR, and hemoglobin A1c were positively associated with polar vasculosis, whereas interstitial fibrosis and tubular atrophy (IFTA) was negatively associated with polar vasculosis. During a median follow-up of 5.2 years, progression of DKD occurred in 322 of 677 (7.4 events/100 person-years) and 79 of 134 (11.4 events/100 person-years) cases with and without polar vasculosis, respectively. Kaplan-Meier analysis showed that polar vasculosis was associated with lower cumulative incidences of DKD progression. Multivariate Cox regression analyses showed that polar vasculosis was associated with a lower risk of DKD progression, regardless of eGFR or proteinuria subgroups. These associations between polar vasculosis and better kidney outcome were unchanged considering all-cause mortality before DKD progression as a competing event. CONCLUSIONS: This study showed that polar vasculosis of DKD was associated with less advanced IFTA and a better kidney outcome in type 2 diabetes with proteinuria.

A comprehensive risk factor analysis using association rules in people with diabetic kidney disease.

Association rule is a transparent machine learning method expected to share information about risks for chronic kidney disease (CKD) among diabetic patients, but its findings in clinical data are limited. We used the association rule to evaluate the risk for kidney disease in General and Worker diabetic cohorts. The absence of risk factors was examined for association with stable kidney function and worsening kidney function. A confidence value was used as an index of association, and a lift of > 1 was considered significant. Analyses were applied for individuals stratified by KDIGO's (Kidney Disease: Improving Global Outcomes) CKD risk categories. A General cohort of 4935 with a mean age of 66.7 years and a Worker cohort of 2153 with a mean age of 47.8 years were included in the analysis. Good glycemic control was significantly related to stable kidney function in low-risk categories among the General cohort, and in very-high risk categories among the Worker cohort; confidences were 0.82 and 0.77, respectively. Similar results were found with poor glycemic control and worsening kidney function; confidences of HbA1c were 0.41 and 0.27, respectively. Similarly, anemia, obesity, and hypertension showed significant relationships in the low-risk General and very-high risk Worker cohorts. Stratified risk assessment using association rules revealed the importance of the presence or absence of risk factors.

Japanese clinical practice patterns of primary nephrotic syndrome 2021: a web-based questionnaire survey of certified nephrologists.

BACKGROUND: With the publication of the "Evidence-Based Clinical Practice Guideline for Nephrotic Syndrome 2020," we examined nephrologists' adherence to the recommendations of four of its clinical questions (CQs). METHODS: This was a cross-sectional web-based survey conducted between November and December 2021. The target population comprised nephrologists certified by the Japanese Society of Nephrology who were recruited using convenience sampling. The participants answered six items regarding the four CQs about adult patients with nephrotic syndrome and their characteristics. RESULTS: In total, 434 respondents worked in at least 306 facilities, of whom 386 (88.9%) provided outpatient care for primary nephrotic syndrome. Of these patients, 179 (41.2%) answered that they would not measure anti- phospholipase A2 receptor antibody levels in cases of suspected primary membranous nephropathy (MN) in which kidney biopsy was not possible (CQ1). Regarding immunosuppressants as maintenance therapy after relapse of minimal change nephrotic syndrome (CQ2), cyclosporine was the most common choice (290 [72.5%] and 300 [75.0%] of 400 respondents after the first and second relapses, respectively). The most common treatment for steroid-resistant cases of primary focal segmental glomerulosclerosis (CQ3) was cyclosporine (323 of 387, 83.5%). For the initial treatment of primary MN with nephrotic-range proteinuria (CQ4), corticosteroid monotherapy was the most common choice (240 of 403, 59.6%), followed by corticosteroid and cyclosporine (114, 28.3%). CONCLUSION: Gaps in recommendations and practices regarding serodiagnosis and treatment of MN (i.e., CQ1 and 4) are observed, suggesting the need to address the barriers to their insurance reimbursement and the lack of evidence behind them.

Public support for patients with intractable diseases in Japan: impact on clinical indicators from nationwide registries in patients with autosomal dominant polycystic kidney disease.

BACKGROUND: Clinical practice guidelines recommend antihypertensive and tolvaptan therapies for patients with autosomal dominant polycystic kidney disease (ADPKD) in Japan. However, tolvaptan therapy may pose an economic burden. The Japanese Ministry of Health, Labour and Welfare supports patients with intractable diseases. This study aimed to confirm the impact of the intractable disease system in Japan on the clinical treatment of ADPKD. METHODS: We analyzed the data of 3768 patients with ADPKD having a medical subsidy certificate from the Japanese Ministry of Health, Labour and Welfare in 2015-2016. The following quality indicators were use: the adherence rate to the 2014 clinical practice guideline for polycystic kidney disease (prescription rates of antihypertensive agents and tolvaptan in this cohort) and the number of Japanese patients with ADPKD nationwide started on renal replacement therapy in 2014 and 2020. RESULTS: Compared with new applications from 2015 to 2016, the prescription rates of antihypertensives and tolvaptan for the indicated patients at the 2017 renewal application increased by 2.0% (odds ratio = 1.41, p = 0.008) and 47.4% (odds ratio = 10.1, p > 0.001), respectively. These quality indicators improved with antihypertensive treatment, especially in patients with chronic kidney disease stages 1-2 (odds ratio = 1.79, p = 0.013) and in those aged < 50 years (odds ratio = 1.70, p = 0.003). The number of patients with ADPKD who were started on renal replacement therapy in Japan decreased from 999 in 2014 to 884 in 2020 in the nationwide database (odds ratio = 0.83, p < 0.001). CONCLUSIONS: The Japanese public intractable disease support system contributes to improvement of ADPKD treatment.

Intra-Brain and Plasma Levels of L-Serine Are Associated with Cognitive Status in Patients with Chronic Kidney Disease.

Introduction: The number of patients with chronic kidney disease (CKD) is increasing worldwide. Cognitive impairment is one of the comorbidities of CKD. With the increased number of aged population, novel biomarkers of impaired cognitive function are required. Intra-body profile of amino acid (AA) is reportedly altered in patients with CKD. Although some AAs act as neurotransmitters in the brain, it is not clear whether altered AA profile are associated with cognitive function in patients with CKD. Therefore, intra-brain and plasma levels of AAs are evaluated with respect to cognitive function in patients with CKD. Methods: Plasma levels of AAs were compared between 14 patients with CKD, including 8 patients with diabetic kidney disease, and 12 healthy controls to identify the alteration of specific AAs in CKD. Then, these AAs were evaluated in the brains of 42 patients with brain tumor using non-tumor lesion of the resected brain. Cognitive function is analyzed with respect to intra-brain levels of AAs and kidney function. Moreover, plasma AAs were analyzed in 32 hemodialyzed patients with/without dementia. Results: In patients with CKD, plasma levels of asparagine (Asn), serine (Ser), alanine (Ala), and proline (Pro) were increased as compared to patients without CKD. Among these AAs, L-Ser, L-Ala, and D-Ser show higher levels than the other AAs in the brain. Intra-brain levels of L-Ser was correlated with cognitive function and kidney function. The number of D-amino acid oxidase or serine racemase-positive cells was not correlated with kidney function. Moreover, the plasma levels of L-Ser are also decreased in patients with declined cognitive function who are treated with chronic hemodialysis. Conclusion: The decreased levels of L-Ser are associated with impaired cognitive function in CKD patients. Especially, plasma L-Ser levels may have a potential for novel biomarker of impaired cognitive function in patients with hemodialysis.

Seasonal variations in renal biopsy numbers and primary glomerular disease features based on the Japan renal biopsy registry.

We analyzed the seasonal variations in the number of renal biopsies and clinical characteristics of primary glomerular disease in Japan using the Japan Renal Biopsy Registry (J-RBR). We retrospectively collected clinical and pathological data of patients with primary glomerular disease who were registered in the J-RBR between 2007 and 2018. Immunoglobulin A nephropathy (IgAN), minimal change nephrotic syndrome (MCNS), membranous nephropathy (MN), and postinfectious acute glomerulonephritis (PIAGN) constituted the four major glomerular disorders included in this study (total, 13,989; IgAN, 9121; MCNS, 2298; MN, 2447; and PIAGN, 123). The number of patients with IgAN or MCNS was higher during summer. However, no overt seasonal variations were observed in patients with MN or PIAGN. Subgroup analyses suggested that in the patients with IgAN, more renal biopsies of severe cases were performed during winter, probably owing to age and blood pressure. Furthermore, more renal biopsies of severe cases were performed during spring and winter in patients with MCNS even after adjusting for the abovementioned host factors. This study suggests that seasonal factors influence the decision to perform renal biopsy as well as the pathogenesis of primary glomerular disease. Thus, our findings may provide important insights regarding the pathophysiology of primary glomerular disease.

Sex differences in risk factors for end-stage kidney disease and death in type 2 diabetes: A retrospective cohort study.

BACKGROUND: This study investigated the sex differences in the risk of end-stage kidney disease (ESKD) and mortality, as well as the effect modification of sex on associated factors in patients with type 2 diabetes. METHODS: This multicenter observational cohort study included 4328 patients with type 2 diabetes. Hazard ratios (HRs) with 95% confidence intervals (CIs) of sex for ESKD and death were estimated using Cox proportional regression with adjustment for baseline covariates. For assessing risk modification, HRs and incidence rates for ESKD and death were compared between sexes across patient characteristics using Cox proportional and Poisson regression models. RESULTS: During a median follow-up of 7 years, 276 patients (70% men) developed ESKD, and 241 patients (68% men) died. Men had higher risks of ESKD (HR 1.34; 95% CI 1.02-1.75; p = .034) and death (HR 1.64; 95% CI 1.24-2.16; p = .001) versus women after adjusting for multiple covariates. Among patients with microalbuminuria, men had a substantially higher risk of ESKD versus women, compared to those with normo- and macroalbuminuria (p for interaction .04). Incidence rates were also increased in men versus women with albuminuria of around 300 mg/g. No differences were detected in the association of sex and death across baseline patient subgroups. CONCLUSIONS: In type 2 diabetes, men had an increased risk of ESKD and death versus women. Moderately increased albuminuria was strongly associated with sex difference in developing ESKD.

Effect of Low-Density Lipoprotein Apheresis on Quality of Life in Patients with Diabetes, Proteinuria, and Hypercholesterolemia.

INTRODUCTION: Treating diabetic nephropathy with low-density lipoprotein (LDL) apheresis reduces proteinuria and improves prognosis. However, its impact on patients' quality of life (QoL) is unclear. This study evaluated the effect of LDL apheresis on QoL in patients with diabetes, proteinuria, and hypercholesterolemia. METHODS: In this nationwide multicenter prospective study, we enrolled 40 patients with diabetes. Inclusion criteria were proteinuria (defined as an albumin/creatinine ratio ≥3 g/g), serum creatinine levels <2 mg/dL, and serum LDL ≥120 mg/dL despite drug treatment. LDL apheresis was performed 6-12 times within 12 weeks. The 36-item Short Form Health Survey (SF-36) was used to analyze QoL. RESULTS: The study enrolled 35 patients (27 men and 8 women; mean age 58.9 ± 11.9 years). A comparison of baseline SF-36 values with those at the end of the course of apheresis found an improvement in the mean physical component summary (37.9 ± 11.4 vs. 40.6 ± 10.5, p = 0.051) and a significant increase in the mean mental component summary (MCS) (49.4 ± 8.4 vs. 52.5 ± 10.9, p = 0.026). A multivariable linear regression analysis revealed a history of coronary heart disease negatively correlated with the MCS increase at the end of the course of apheresis (ß coefficient -6.935, 95% confidence interval, 13.313 to-0.556, p = 0.034). CONCLUSION: Our results suggest that LDL apheresis may improve the mental and physical QoL in patients with diabetes, proteinuria, and hypercholesterolemia.

A Case of Spontaneous Remission of Membranous Nephropathy After the Removal of Nerve Epidermal Growth Factor-Like 1 Positive Sigmoid Colon Carcinoma.

Recently, the association between membranous nephropathy (MN) and malignancy has been recognized in about 30% of epidermal growth factor-like 1 (NELL-1) positive cases. However, the mechanism of association with MN and malignancy remains under search. In this report, we present a unique case of MN with positive staining for both thrombospondin type-1 domain-containing 7A (THSD7A) and NELL-1. An 80-year-old Japanese woman with nephrotic syndrome (NS) was diagnosed as an immunoglobulin (Ig)G1 subclass predominant secondary MN with weakly positive for THSD7A staining. Then, advanced cancer in the sigmoid colon was found during screening tests for malignancy. After the removal of colon carcinoma, complete remission was achieved at 28 weeks follow-up after operation. Five years later, she remained in remission and passed without recurrence. Thereafter, we examined again newly reported NELL-1 in renal biopsy specimens and found very strong staining along the glomerular capillary walls. Moreover, in resected tumor tissues, NELL-1 was strongly positive at the basal side of adenocarcinoma cells, but THSD7A staining was negative. This case report provides clinical details and highlights the utility of autoantibodies, especially NELL-1, in the diagnosis and treatment of secondary MN with malignancy.

Increased levels of oral Streptococcus-derived D-alanine in patients with chronic kidney disease and diabetes mellitus.

The number of patients on hemodialysis is increasing globally; diabetes mellitus (DM) complications is the major cause of hemodialysis in patients with chronic kidney disease (CKD). The D-amino acid (AA) profile is altered in patients with CKD; however, it has not been studied in patients with CKD and DM. Furthermore, bacteria responsible for altering the D-AA profile are not well understood. Therefore, we examined the D-AA profiles and associated bacteria in patients with CKD, with and without DM. We enrolled 12 healthy controls and 54 patients with CKD, with and without DM, and determined their salivary, stool, plasma, and urine chiral AA levels using two-dimensional high-performance liquid chromatography. We performed 16S rRNA gene sequencing analysis of the oral and gut microbiota to determine the association between the abundance of bacterial species and D-AA levels. Plasma D-alanine and D-serine levels were higher in patients with CKD than in healthy adults (p < 0.01), and plasma D-alanine levels were higher in patients with CKD and DM than in those without DM. The abundance of salivary Streptococcus, which produced D-alanine, increased in patients with CKD and DM and was positively correlated with plasma D-alanine levels. Patients with CKD and DM had unique oral microbiota and D-alanine profiles. Plasma D-alanine is a potential biomarker for patients with CKD and DM.

[Management of Chronic Kidney Disease in Cancer Survivors].

Chronic kidney disease(CKD)associated with cancer and its treatment affects life after cancer treatment. There is inconclusive opinion on whether CKD treatment in survivors after cancer treatment needs special care differently than in the general population with CKD. Several topics were discussed by nephrologists, urologists and medical oncologists, pediatricians, pharmaceutical specialists, and others based on the results of a literature search, and the consensus was documented in the "Clinical Practice Guidelines for the Management for Kidney Injury During Anticancer Drug Therapy, 2022". The prevalence of CKD among adult cancer survivors is reported to be 4-7%. The characteristics include(1)elderly and physically impaired patients(, 2)a high risk of cancer recurrence, and(3)frequently cancer treatment-related CKD. Although there are no cancer survivor-specific indications or contraindications in the selection of renal replacement therapy, renal transplantation is often preferred in pediatric cancer survivors. It was determined that it is not appropriate to recommend or not recommend the administration of erythropoietin stimulating agents for renal anemia in cancer survivors based on a systematic review and discussion between panelists. When used in individual cases, its application should be well examined and consideration should be given to avoiding high hemoglobin level and to monitoring for cancer development.

Kif26b contributes to the progression of interstitial fibrosis via migration and myofibroblast differentiation in renal fibroblast.

Kinesin family member 26b (Kif26b) is essential for kidney development, and its deletion in mice leads to kidney agenesis. However, the roles of this gene in adult settings remain elusive. Thus, this study aims to investigate the role of Kif26b in the progression of renal fibrosis. A renal fibrosis model with adenine administration using Kif26b heterozygous mice and wild-type mice was established. Renal fibrosis and the underlying mechanism were investigated. The underlying pathways and functions of Kif26b were evaluated in an in vitro model using primary renal fibroblasts. Kif26b heterozygous mice were protected from renal fibrosis with adenine administration. Renal expressions of connective tissue growth factor (CTGF) and myofibroblast accumulation were reduced in Kif26b heterozygous mice. The expression of nonmuscle myosin heavy chain II (NMHCII), which binds to the C-terminus of Kif26b protein, was also suppressed in Kif26b heterozygous mice. The in vitro study revealed reduced expressions of CTGF, α-smooth muscle actin, and myosin heavy chain 9 (Myh9) via transfection with siRNAs targeting Kif26b in renal fibroblasts (RFB). RFBs, which were transfected by the expression vector of Kif26b, demonstrated higher expressions of these genes than non-transfected cells. Finally, Kif26b suppression and NMHCII blockage led to reduced abilities of migration and collagen gel contraction in renal fibroblasts. Taken together, Kif26b contributes to the progression of interstitial fibrosis via migration and myofibroblast differentiation through Myh9 in the renal fibrosis model. Blockage of this pathway at appropriate timing might be a therapeutic approach for renal fibrosis.

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

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