The presence of exudative thickening of Bowman's capsule predict poor prognosis in diabetic kidney disease

BACKGROUND

The relationship between Bowman's capsule thickening and progression of diabetic kidney disease (DKD) remains uncertain.

METHODS

Renal biopsy specimens from 145 DKD patients and 20 control subjects were evaluated for Bowman's capsule thickness. Immunohistochemical staining assessed col4α2, laminin β1, and albumin expression. In a discovery cohort of 111 DKD patients with eGFR ≥ 30 ml/min/1.73 m2, thickening was classified as fibrotic or exudative. The composite endpoint included CKD stage 5, dialysis initiation, and renal disease-related death. Prognosis was analyzed using Kaplan-Meier and Cox regression analyses. Two validation cohorts were included.

RESULTS

Three types of thickening were observed: fibrotic, exudative, and periglomerular fibrosis. Parietal epithelial cell matrix protein accumulation contributed to fibrotic thickening, while albumin was present in exudative thickening. Bowman's capsule was significantly thicker in DKD patients (5.74 ± 2.09 μm) compared to controls (3.38 ± 0.43 μm, P < 0.01). In discovery cohort, the group of exudative thickning had a poorer prognosis(median time 20 months vs 57 months, P = 0.000). Cox multivariate analysis revealed that exudative thickening of Bowman's capsule were associated with a poor prognosis. The validation cohorts confirmed the result.

CONCLUSIONS

Various mechanisms contribute to Bowman's capsule thickening in DKD. The proportion of exudative thickening may serve as a valuable prognostic indicator for DKD patients.

Renal transcriptome analysis of uninephrectomized db/db mice identified a mechanism for the transition to severe diabetic nephropathy

Diabetic nephropathy (DN), included in diabetic kidney disease (DKD), is a primary driver of end-stage renal disease (ESRD) leading to dialysis treatment. To develop new therapeutic drugs to prevent ESRD and avoid dialysis treatment, insight into DKD pathophysiology and animal models suitable for drug efficacy testing are needed. In this study, transcriptome analysis of kidneys from 26-week-old and 35-week-old uninephrectomized (UNX) db/db mice was used to identify the pathways that affect the deterioration of renal function in db/db mice. Differentially expressed genes suggested that there was increased interferon (IFN)-γ signaling during the 26 to 35-week period. Modules that changed between 26 and 35 weeks of age extracted by weighted gene co-expression network analysis (WGCNA) suggested increased the tumor necrosis factor (TNF)-α and nuclear factor-kappa B (NF-κB) signaling pathway in component cells of glomeruli. The protein-protein interaction (PPI) network analysis identified Cxcl16 as a hub gene for those signaling pathways, and it was shown that the pathways in this module changed when the glomerular filtration rate decreased in patients with DN. These results suggested the possibility that signaling mediated by Cxcl16 induced by IFN-γ and TNF-α between 26 and 35 weeks of age leads to renal fibrosis, resulting in severe disease. Drugs that target such pathways can be options for developing drugs for DN. We also think that the uninephrectomized db/db mouse can be used as an animal model of severe DKD and to evaluate efficacy in patients with DN.

Coexistence of nephrogenic systemic fibrosis and calciphylaxis in a gadolinium-naïve, chronic haemodialysis patient

We present a case of a man in his 40s who was on haemodialysis for over 20 years presenting with rapidly progressive decline in mobility, associated with fixed flexion deformities of joints and peau d'orange appearance of skin together with areas of ulceration that was concerning for calciphylaxis. Skin biopsies were consistent with both nephrogenic systemic fibrosis and calciphylaxis. He has never had exposure to gadolinium-based contrast agent. His treatment included daily dialysis sessions, which were challenging due to vascular access issues and three times weekly sodium thiosulfate. He rapidly declined in hospital and died within 2 weeks of presentation while being treated for a hospital-acquired pneumonia.

Utilization of the corticomedullary difference in magnetic resonance imaging-derived apparent diffusion coefficient for noninvasive assessment of chronic kidney disease in type 2 diabetes

BACKGROUNDS

Accumulating data demonstrated that the cortico-medullary difference in apparent diffusion coefficient (ΔADC) of diffusion-weighted magnetic resonance imaging (DWI) was a better correlation with kidney fibrosis, tubular atrophy progression, and a predictor of kidney function evolution in chronic kidney disease (CKD).

OBJECTIVES

We aimed to assess the value of ΔADC in evaluating disease severity, differential diagnosis, and the prognostic risk stratification for patients with type 2 diabetes (T2D) and CKD.

METHODS

Total 119 patients with T2D and CKD who underwent renal MRI were prospectively enrolled. Of them, 89 patients had performed kidney biopsy for pathological examination, including 38 patients with biopsy-proven diabetic kidney disease (DKD) and 51 patients with biopsy-proven non-diabetic kidney disease (NDKD) and Mix (DKD + NDKD). Clinicopathological characteristics were compared according to different ΔADC levels. Moreover, univariate and multivariate-linear regression analyses were performed to explore whether ΔADC was independently associated with estimated glomerular filtration rate (eGFR) and urinary albumin creatinine ratio (UACR). The diagnostic performance of ΔADC for discriminating DKD from NDKD + Mix was evaluated by receiver operating characteristic (ROC) analysis. In addition, an individual's 2- or 5-year risk probability of progressing to end-stage kidney disease (ESKD) was calculated by the kidney failure risk equation (KFRE). The effect of ΔADC on prognostic risk stratification was assessed. Additionally, net reclassification improvement (NRI) was used to evaluate the model performance.

RESULTS

All enrolled patients had a median ΔADC level of 86 (IQR 28, 155) × 10-6 mm2/s. ΔADC significantly decreased across the increasing staging of CKD (P < 0.001). Moreover, those with pathological-confirmed DKD has a significantly lower level of ΔADC than those with NDKD and Mix (P < 0.001). It showed that ΔADC was independently associated with eGFR (β = 1.058, 95% CI = [1.002,1.118], P = 0.042) and UACR (β = -3.862, 95% CI = [-7.360, -0.365], P = 0.031) at multivariate linear regression analyses. Besides, ΔADC achieved an AUC of 0.707 (71% sensitivity and 75% specificity) and AUC of 0.823 (94% sensitivity and 67% specificity) for discriminating DKD from NDKD + Mix and higher ESKD risk categories (≥50% at 5 years; ≥10% at 2 years) from lower risk categories (<50% at 5 years; <10% at 2 years). Accordingly, the optimal cutoff value of ΔADC for higher ESKD risk categories was 66 × 10-6 mm2/s, and the group with the low-cutoff level of ΔADC group was associated with 1.232 -fold (95% CI 1.086, 1.398) likelihood of higher ESKD risk categories as compared to the high-cutoff level of ΔADC group in the fully-adjusted model. Reclassification analyses confirmed that the final adjusted model improved NRI.

CONCLUSIONS

ΔADC was strongly associated with eGFR and UACR in patients with T2D and CKD. More importantly, baseline ΔADC was predictive of higher ESKD risk, independently of significant clinical confounding. Specifically, ΔADC <78 × 10-6 mm2/s and <66 × 10-6 mm2/s would help to identify T2D patients with the diagnosis of DKD and higher ESKD risk categories, respectively.

G Protein Coupled Receptor 87 (GPR87) in End Stage Kidney and Associated Tumors

BACKGROUND/AIM

End-stage renal disease (ESRD) and acquired cystic renal disease (ACRD) are characterized by progressive inflammation, structural remodeling and by development of unique cancer types. Eosinophilic-vacuolated and chromophobe-like renal cell carcinoma develop exclusively in ACRD kidney. The aim of the study was to investigate the molecular mechanism of ESRD/ACRD carcinogenesis.

MATERIALS AND METHODS

Our previous Affymetrix array analysis detected GPR87 as one of the highly and specifically expressed genes in ESRD/ACRD kidneys. In this study we analyzed normal and ESRD/ACRD kidneys and related tumors for GPR87 expression by PCR, RT-PCR, and immunohistochemistry.

RESULTS

Immunohistochemistry revealed a strong GPR87 expression in proliferating epithelial cells in ESRD/ACRD kidneys and in cells of eosinophilic-vacuolated and chromophobe-like renal cell carcinoma.

CONCLUSION

GPR87 signaling plays an important role in the structural remodeling of ESRD/ACRD kidney and development of ACRD-associated tumors with unique histology.

Comparison of the effects of peritoneal dialysis and hemodialysis on spontaneous brain activity in CKD patients: an rs-fMRI study

OBJECTIVE

To compare the effects of peritoneal dialysis and hemodialysis on spontaneous brain activity in patients with end-stage renal disease.

METHODS

A total of 52 dialysis patients with end-stage renal disease, including 25 patients with chronic kidney disease undergoing hemodialysis (HD-CKD) and 27 patients with chronic kidney disease undergoing peritoneal dialysis (PD-CKD), and 49 healthy controls (normal control) were included. All participants underwent neuropsychological testing (Mini-Mental State Examination and Montreal cognitive assessment) and resting-state functional magnetic resonance imaging. Fractional amplitude of low frequency fluctuations and Regional Homogeneity algorithms were employed to evaluate spontaneous brain activity. Statistical analysis was performed to discern differences between the groups.

RESULTS

When compared with the normal control group, the PD-CKD group exhibited significant alterations in fractional amplitude of low frequency fluctuations in various cerebellum regions and other brain areas, while the HD-CKD group showed decreased fractional amplitude of low frequency fluctuations in the bilateral pericalcarine cortex. The Regional Homogeneity values in the PD-CKD group were notably different than those in the normal control group, particularly in regions such as the bilateral caudate nucleus and the right putamen.

CONCLUSION

Both peritoneal dialysis and hemodialysis modalities impact brain activity, but manifest differently in end-stage renal disease patients. Understanding these differences is crucial for optimizing patient care.

External validation of the pediatric International IgA Nephropathy Prediction Tool in a central China cohort

BACKGROUND

This study aimed to externally validate the pediatric International IgA Nephropathy (IgAN) Prediction Tool updated from the adult IgAN Prediction Tool.

METHODS

439 children with biopsy-confirmed idiopathic IgAN were enrolled in this external validation study. The primary outcome was a 30% decline in eGFR or end-stage kidney disease. We evaluated the discrimination using Harrell's C-index, the receiver operating characteristic (ROC) curve, and Kaplan-Meier curves for four risk groups (< 16th [low risk], ∼16 to < 50th [intermediate risk], ∼50 to < 84th [high risk], and ≥ 84th percentiles [highest risk] of linear predictor). Calibration was assessed using calibration plots.

RESULTS

The median follow-up time of the 439 patients was 4.5 (2.7-6.8) years, and 27 patients reached the primary outcome. Compared with the reported cohorts, our cohort was more contemporary, with milder proteinuria at biopsy, and had lower proportions of S1 and T1 lesions. Harrell's C-index and area under the ROC curve at 5 years were < 0.7 for both the models with and without race. The Kaplan-Meier curves of the risk groups were not well separated for the two models, only separated completely between the highest-risk group and the others for the model without race. The two models generally overestimated the risk of the primary outcome, CONCLUSION: The model without race could accurately distinguish the highest-risk patients from patients with low, intermediate, and high risk for kidney progression. Discrimination and calibration for the full model with or without race were unsatisfactory in this contemporary cohort in central China.

Comparison of Clinico-pathologic features and outcomes of ANCA negative and ANCA positive pauci immune crescentic glomerulonephritis: A single centre study

Introduction

Pauci-immune crescentic glomerulonephritis (PICN) is an important cause of rapidly progressive renal failure. 10-40% of PICN cases have ANCA (antineutrophil cytoplasmic antibody) negative serology. The present study compared clinico-pathologic features, Brix's renal risk score, Berden's histopathological classes and differences in outcome between ANCAnegative vs ANCA positive PICN patients.

Materials and Methods

Sixty-one patients of biopsy-proven PICN were studied. Biochemical findings and ANCA serology were recorded. Renal biopsy slides were reviewed along with direct immunofluorescence. Clinical and histological features were compared between ANCA negative and positive PICN using the Man Whitney U test and Chi-square test. Patients were compared for distribution in Berden's histological classes and Brix's renal risk categories. Patient and renal survival were compared using Kaplan-Meier survival analysis.

Results

ANCA negative PICN patients were younger (44.9 ± 16.5 years vs 53.6 ± 15.1 years, P = 0.049). Nasal (0 vs 18%, P = 0.035) and pulmonary involvement (9% vs 38%, P = 0.014) were lower in ANCA negative group. Both ANCA groups had similar renal biochemical profiles, percentage normal glomeruli, 16.3 ± 18.2 vs 21.7 ± 20.4 and percentage glomeruli with crescents, 64.5 ± 28.1 vs 64.3 ± 27.1. Twenty-seven per cent of ANCA negative cases fell in the sclerotic class in Berden's classification vs just 2.5% in ANCA positive group (p = 0.037) without significant difference in Brix's renal risk categories (p = 0.329). Thirteen per cent of ANCA negative patients achieved complete remission on treatment compared to 33% in ANCA positive patients. Patient survival and overall probability of progressing to ESRD were similar in the two groups.

Conclusion

ANCA negative PICN cases present at younger ages. Nasal and pulmonary involvement is uncommon in these patients. Patient survival and progression to ESRD are similar in both ANCA groups.

[Long-term auditory monitoring in children with Alport syndrome based on different degrees of renal injury]

Objective:To investigate long-term auditory changes and characteristics of Alport syndrome（AS） patients with different degrees of renal injury. Methods:Retrospectively analyzing clinical data of patients diagnosed AS from January 2007 to September 2022, including renal pathology, genetic detection and hearing examination. A long-term follow-up focusing on hearing and renal function was conducted. Results:This study included 70 AS patients, of which 33（25 males, 8 females, aged 3.4-27.8 years） were followed up, resulting in a loss rate of 52.9%.The follow-up period ranged from 1.1to 15.8 years, with 16 patients followed-up for over 10 years. During the follow-up, 10 patients presenting with hearing abnormalities at the time of diagnosis of AS had progressive hearing loss, and 3 patients with new hearing abnormalities were followed up, which appeared at 5-6 years of disease course. All of which were sensorineural deafness. While only 3 patients with hearing abnormalities among 13 patients received hearing aid intervention. Of these patients,7 developed end-stage renal disease（ESRD）, predominantly males （6/7）. The rate of long-term hearing loss was significantly different between ESRD group and non-ESRD group（P=0.013）. There was no correlation between the progression of renal disease and long-term hearing level（P>0.05）. kidney biopsies from 28 patients revealed varying degrees of podocyte lesion and uneven thickness of basement membrane. The severity of podocyte lesion was correlated with the rate of long-term hearing loss（P=0.048）, and there was no correlation with the severity of hearing loss（P>0.05）. Among 11 cases, theCOL4A5mutationwas most common （8 out of 11）, but there was no significant correlation between the mutation type and hearing phenotype（P>0.05）. Conclusion:AS patients exhibit progressive hearing loss with significant heterogeneity over the long-term.. THearing loss is more likely to occur 5-6 years into the disease course. Hearing abnormalities are closely related to renal disease status, kidney tissue pathology, and gene mutations, emphasizing the need for vigilant long-term hearing follow-up and early intervention.

Validation of a renal risk score in a cohort of children with ANCA-associated glomerulonephritis

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is extremely rare in children. Renal involvement is a common and severe complication of AAV as it can cause end stage kidney disease (ESKD). ANCA renal risk score (ARRS) is helpful in predicting long-term ESKD in patients with ANCA-associated glomerulonephritis (AAGN). This retrospective study included 61 consecutive patients with kidney biopsy specimen-proven AAGN from Clinical Center for Children's Kidney Disease in China. Each patient was assessed by eGFR, normal glomeruli, and tubular atrophy/interstitial fibrosis, and the renal outcome was evaluated using the ARRS. Based on the ARRS, 27 (44.26%), 21 (34.43%), and 13 (21.31%) patients were divided into the low-risk, medium-risk, and high-risk groups, respectively. The median follow-up period was 46.36 (14.58-95.62) months. The high-risk group had worse renal outcomes than the low-risk group (p< 0.05) and the medium-risk group (p < 0.05). COX multivariate regression analysis showed that eGFR ≤ 15 ml/min/1.73 m2 (p = 0.015, Hazard Ratio (HR) = 9.574, 95% CI 4.205-25.187) and ARRS (p = 0.012, HR = 2.115, 95% CI 1.206-4.174) were independent risk factors for ESKD.The area under the curve for ESKD prediction of ARRS was 0.880, and the best cutoff value was 5.50. Delong test result showed that ARRS exhibited better predictive value for ESKD than the Berden classification (p < 0.001) and rapidly progressive glomerulonephritis (p < 0.001). This is the first study to investigate the value of the ARRS for predicting renal prognosis among Chinese children. The ARRS is a preferred index that can predict ESKD in Chinese children with AAGN.

Long-term survival and renal outcomes of thrombotic microangiopathy in pregnancy: A retrospective cohort study

OBJECTIVE

Thrombotic microangiopathy (TMA) in pregnancy can rapidly progress, leading to severe morbidities. This study aimed to compare baseline demographics and clinical outcomes between pregnant women with and without TMA.

METHODS

Using the National Health Insurance Research Database, 207 patients with pregnancy-related TMA from January 1, 2006 to December 31, 2015 were enrolled. Their data were compared with a 1:4 propensity score-matched cohort of 828 pregnant women without TMA to evaluate mortality and end-stage renal disease (ESRD) risks. Cox proportional hazards models were used to estimate the adjusted hazard ratio and 95% confidence intervals.

RESULTS

A total of 1035 participants were included. The risks of mortality and ESRD were 4.46 and 5.97 times higher for the TMA cohort, respectively. Subgroup analysis revealed higher mortality and ESRD risks in patients with TMA aged >40 years with a history of hypertension, stroke, cancer, concomitant stroke, malignant hypertension, or gastroenterocolitis than in the matched cohort.

CONCLUSION

Pregnant patients with TMA, especially those older and with comorbidities and organ involvement, faced increased mortality and ESRD risks. Physicians should collaborate with obstetricians throughout the prenatal and postpartum periods for these patients.

Pharmacokinetic-pharmacodynamic modeling of the active components of Shenkang injection in rats with chronic renal failure and its protective effect on damaged renal cells

The study aimed to explore the pharmacokinetic and pharmacodynamic alterations of the active components of Shenkang injection (i.e. hydroxy saffron yellow pigment A [HSYA], tanshinol, rheum emodin, and astragaloside IV) in rats with chronic renal failure (CRF), and establish a pharmacokinetic-pharmacodynamic model (PK-PD model) in order to provide a scientific and theoretical basis for the rational clinical use of Shenkang injection. Sprague-Dawley (SD) rats were randomly divided into a normal group, model group, and Shenkang injection group. A rat model of CRF was induced by adenine gavage and then followed by drug administration via tail vein injection. Orbital blood was collected at different timepoints and the blood concentrations of the four active components were measured by UHPLC-Q-Orbitrap HRMS. Serum levels of creatinine (Scr), urea nitrogen (BUN), and uric acid (UA) were determined using an automatic biochemical analyzer. A PK-PD model was established, and DAS 3.2.6 software was used for model fitting as well as statistical analysis. TGF-β1 was utilized to induce normal rat kidney cells to construct a renal fibrosis model to investigate the protective effect of the pharmacological components on renal fibrosis. The pharmacokinetic analysis of hydroxy saffron yellow pigment A, tanshinol, rheum emodin, and astragaloside IV based on UHPLC-Q-Orbitrap HRMS was stable. The linear regression equations for the four active components were as follows: Y = 0.031X + 0.0091 (R2  = 0.9986) for hydroxy saffron yellow pigment A, Y = 0.0389X + 0.164 (R2  = 0.9979) for tanshinol, Y = 0.0257X + 0.0146 (R2  = 0.9973) for rheum emodin, and Y = 0.0763X + 0.0139 (R2  = 0.9993) for astragaloside IV, which indicated good linear relationships. The methodological investigation was stable, with the interday and intraday precision RSD <10%. Meanwhile, the recoveries ranged between 90% and 120%, in accordance with the requirements for in vivo analysis of drugs. Compared with the model group, the levels of Scr, BUN, and UA were significantly decreased after 20 min in the Shenkang injection group (p < 0.01). The PK-PD model showed that the four active components in the Shenkang injection group could fit well with the three effect measures (i.e. Scr, BUN, and UA), with the measured values similar to the predicted values. The cell model of renal fibrosis showed that the connective tissue growth factor and FN1 protein expression levels were significantly lower in the Shenkang injection group than those in the model group, and the cell fibrosis was improved. The established method for in vivo analysis of Shenkang injection was highly specific, with good separation of the components and simple operation. The total statistical moment could well integrate the pharmacokinetic parameters of the four active components. After treatment with Shenkang injection, all indexes in the administered group improved and showed significant inhibition of renal cell fibrosis in vitro. This study could provide scientific reference ideas for the clinical rational use of traditional Chinese medicine.

Uric acid-based ratios for predicting renal failure in Chinese IgA nephropathy patients

Objective: The uric acid/albumin ratio (UAR), a novel, simple, and compositive laboratory biomarker, has recently attracted attention for predicting disease prediction and disease prognosis. However, whether uric acid-related biomarkers (especially UAR) could serve as prognostic indicator for IgAN is unclear. Methods: In this retrospective cohort study, biopsy-confirmed IgAN patients from 2009 to 2017 from West China Hospital were evaluated. The optimal cutoff value of UAR for renal outcome was defined using the Youden index by the area under receiver operating characteristic curve (AUC). The patients were then categorized into the high UAR group and the low UAR group. Renal endpoints were defined as progression to ESRD, eGFR decreased ≥50% of the baseline level, or initiation of renal replacement treatment. Kaplan‒Meier survival analysis and Cox regression analysis were used to identify factors influencing IgAN outcomes. Results: A total of 1143 patients with a median age of 33.0 (26.0-42.0) (44.2% men) were included in the study. The best cut-off UAR concerned with renal survival was determined to be 9.94 with a specificity of 77.5% and a sensitivity of 61.5% (J, 0.390; AUC, 0.750). Then, the patients were divided into two groups labelled as low and high UAR ratios (≥ 9.94 and <9.94, respectively). More severe clinical manifestations and pathological lesions were observed in the high UAR group. Multivariate Cox regression analysis after adjusted for important clinicopathological parameters manifested that a high UAR was an independent prognostic biomarker for IgAN. (p = 0.036, HR =2.56, 95% CI: 1.07-6.16). Conclusion: UAR might be a novel predictor for renal progression and contribute to targeted management.

Disrupted network communication predicts mild cognitive impairment in end-stage renal disease: an individualized machine learning study based on resting-state fMRI

End-Stage Renal Disease (ESRD) is known to be associated with a range of brain injuries, including cognitive decline. The purpose of this study is to investigate the functional connectivity (FC) of the resting-state networks (RSNs) through resting state functional magnetic resonance imaging (MRI), in order to gain insight into the neuropathological mechanism of ESRD. A total of 48 ESRD patients and 49 healthy controls underwent resting-state functional MRI and neuropsychological tests, for which Independent Components Analysis and graph-theory (GT) analysis were utilized. With the machine learning results, we examined the connections between RSNs abnormalities and neuropsychological test scores. Combining intra/inter network FC differences and GT results, ESRD was optimally distinguished in the testing dataset, with a balanced accuracy of 0.917 and area under curve (AUC) of 0.942. Shapley additive explanations results revealed that the increased functional network connectivity between DMN and left frontoparietal network (LFPN) was the most critical predictor for ESRD associated mild cognitive impairment diagnosis. Moreover, hypoSN (salience network) was positively correlated with Attention scores, while hyperLFPN was negatively correlated with Execution scores, indicating correlations between functional disruption and cognitive impairment measurements in ESRD patients. This study demonstrated that both the loss of FC within the SN and compensatory FC within the lateral frontoparietal network coexist in ESRD. This provides a network basis for understanding the individual brain circuits and offers additional noninvasive evidence to comprehend the brain networks in ESRD.

Rodent models to study type 1 and type 2 diabetes induced human diabetic nephropathy

INTRODUCTION

Diabetic nephropathy (DN), an outcome of prolonged diabetes, has affected millions of people worldwide and every year the incidence and prevalence increase substantially. The symptoms may start with mild manifestations of the disease such as increased albuminuria, serum creatinine levels, thickening of glomerular basement membrane, expansion of mesangial matrix to severe pathological symptoms such as glomerular lesions and tubulointerstitial fibrosis which may further proceed to cardiovascular dysfunction or end-stage renal disease.

PERSPECTIVE

Numerous therapeutic interventions are being explored for the management of DN, however, these interventions do not completely halt the progression of this disease and hence animal models are being explored to identify critical genetic and molecular parameters which could help in tackling the disease. Rodent models which mostly include mice and rats are commonly used experimental animals which provide a wide range of advantages in understanding the onset and progression of disease in humans and also their response to a wide range of interventions helps in the development of effective therapeutics. Rodent models of type 1 and type 2 diabetes induced DN have been developed utilizing different platforms and interventions during the last few decades some of which mimic various stages of diabetes ranging from early to later stages. However, a rodent model which replicates all the features of human DN is still lacking. This review tries to evaluate the rodent models that are currently available and understand their features and limitations which may help in further development of more robust models of human DN.

CONCLUSION

Using these rodent models can help to understand different aspects of human DN although further research is required to develop more robust models utilizing diverse genetic platforms which may, in turn, assist in developing effective interventions to target the disease at different levels.

Palm-Plant Pain, Sign of a Severe Systemic Disease? Case Report and Review of Literature

Fabry disease is an X-linked lysosomal storage disease, second in prevalence after Gaucher disease. The onset of symptoms occurs in childhood or adolescence with palmo-plantar burning pains, hypo hidrosis, angiokeratomas, and corneal deposits. In the absence of diagnosis and treatment, the disease will progress to the late phase, characterized by progressive cardiac, cerebral and renal damage, and possible death. We present the case of an 11-year-old male boy who was transferred to the Pediatric Nephrology Department for palmo-plantar burning pain and end stage renal disease. Following the evaluations for the etiology of end stage renal disease we excluded the vasculitis, the neurologic diseases, extrapulmonary tuberculosis. Because of suggestive aspect at CT scan and lack of etiologic diagnosis of renal insufficiency we performed lymph node and kidney biopsy, with a surprising result for storage disease. The specific investigation confirmed the diagnosis.

Kidney biopsy diagnosis in childhood in the Norwegian Kidney Biopsy Registry and the long-term risk of kidney replacement therapy: a 25-year follow-up

BACKGROUND

There is scarce information on biopsy-verified kidney disease in childhood and its progression to chronic kidney disease stage 5 (CKD 5). This study aims to review biopsy findings in children, and to investigate risk of kidney replacement therapy (KRT).

METHODS

We conducted a retrospective long-term follow-up study of children included in the Norwegian Kidney Biopsy Registry (NKBR) and in the Norwegian Renal Registry (NRR) from 1988 to 2021.

RESULTS

In total, 575 children with a median (interquartile range, IQR) age of 10.7 (6.1 to 14.1) years were included, and median follow-up time (IQR) after kidney biopsy was 14.3 (range 8.9 to 21.6) years. The most common biopsy diagnoses were minimal change disease (MCD; n = 92), IgA vasculitis nephritis (IgAVN; n = 76), IgA nephropathy (n = 63), and focal and segmental glomerulosclerosis (FSGS; n = 47). In total, 118 (20.5%) of the biopsied children reached CKD 5, median (IQR) time to KRT 2.3 years (7 months to 8.4 years). Most frequently, nephronophthisis (NPHP; n = 16), FSGS (n = 30), IgA nephropathy (n = 9), and membranoproliferative glomerulonephritis (MPGN; n = 9) led to KRT.

CONCLUSIONS

The risk of KRT after a kidney biopsy diagnosis is highly dependent on the diagnosis. None of the children with MCD commenced KRT, while 63.8% with FSGS and 100% with NPHP reached KRT. Combining data from kidney biopsy registries with registries on KRT allows for detailed information concerning the risk for later CKD 5 after biopsy-verified kidney disease in childhood. A higher resolution version of the Graphical abstract is available as Supplementary information.

Effects of salt supplementation in uninephrectomized KK-Ay mice: Examining the potential of a diabetic kidney disease model

Diabetic kidney disease (DKD) is the leading cause of end-stage renal disease (ESRD). Although current therapeutic strategies for DKD, including sodium-glucose cotransporter-2 inhibitors and mineralocorticoid receptor antagonists, have shown some degree of efficacy, they have failed to completely halt the progression of DKD to ESRD owing to the complexity of DKD pathogenesis. Elucidating the pathophysiological mechanism of DKD is essential for the development of novel therapeutic strategies. In this study, we investigated the pathophysiological characteristics of uninephrectomized (UNx) KK-Ay mice and examined the effects of salt supplementation on the acceleration of renal injury in these mice. UNx KK-Ay mice exhibited pathophysiological renal abnormalities with glomerular and tubulointerstitial fibrosis. Additionally, salt supplementation exacerbated renal injury, particularly tubular injury. These results suggest that UNx KK-Ay mice are useful models for advanced DKD and that salt exacerbates tubular damage in DKD.

Molecular mechanisms governing the progression of nephritis in lupus prone mice and human lupus patients

Introduction

Pathologic inflammation is a major driver of kidney damage in lupus nephritis (LN), but the immune mechanisms of disease progression and risk factors for end organ damage are poorly understood.

Methods

To characterize molecular profiles through the development of LN, we carried out gene expression analysis of microdissected kidneys from lupus-prone NZM2328 mice. We examined male mice and the congenic NZM2328.R27 strain as a means to define mechanisms associated with resistance to chronic nephritis. Gene expression profiles in lupus mice were compared with those in human LN.

Results

NZM2328 mice exhibited progress from acute to transitional and then to chronic glomerulonephritis (GN). Each stage manifested a unique molecular profile. Neither male mice nor R27 mice progressed past the acute GN stage, with the former exhibiting minimal immune infiltration and the latter enrichment of immunoregulatory gene signatures in conjunction with robust kidney tubule cell profiles indicative of resistance to cellular damage. The gene expression profiles of human LN were similar to those noted in the NZM2328 mouse suggesting comparable stages of LN progression.

Conclusions

Overall, this work provides a comprehensive examination of the immune processes involved in progression of murine LN and thus contributes to our understanding of the risk factors for end-stage renal disease. In addition, this work presents a foundation for improved classification of LN and illustrates the applicability of murine models to identify the stages of human disease.

Endoglin Is an Important Mediator in the Final Common Pathway of Chronic Kidney Disease to End-Stage Renal Disease

Chronic kidney disease (CKD) is a slow-developing, progressive deterioration of renal function. The final common pathway in the pathophysiology of CKD involves glomerular sclerosis, tubular atrophy and interstitial fibrosis. Transforming growth factor-beta (TGF-β) stimulates the differentiation of fibroblasts towards myofibroblasts and the production of extracellular matrix (ECM) molecules, and thereby interstitial fibrosis. It has been shown that endoglin (ENG, CD105), primarily expressed in endothelial cells and fibroblasts, can function as a co-receptor of TGF signaling. In several human organs, endoglin tends to be upregulated when chronic damage and fibrosis is present. We hypothesize that endoglin is upregulated in renal interstitial fibrosis and plays a role in the progression of CKD. We first measured renal endoglin expression in biopsy samples obtained from patients with different types of CKD, i.e., IgA nephropathy, focal segmental glomerulosclerosis (FSGS), diabetic nephropathy (DN) and patients with chronic allograft dysfunction (CAD). We showed that endoglin is upregulated in CAD patients (p < 0.001) and patients with DN (p < 0.05), compared to control kidneys. Furthermore, the amount of interstitial endoglin expression correlated with eGFR (p < 0.001) and the amount of interstitial fibrosis (p < 0.001), independent of the diagnosis of the biopsies. Finally, we investigated in vitro the effect of endoglin overexpression in TGF-β stimulated human kidney fibroblasts. Overexpression of endoglin resulted in an enhanced ACTA2, CCN2 and SERPINE1 mRNA response (p < 0.05). It also increased the mRNA and protein upregulation of the ECM components collagen type I (COL1A1) and fibronectin (FN1) (p < 0.05). Our results suggest that endoglin is an important mediator in the final common pathway of CKD and could be used as a possible new therapeutic target to counteract the progression towards end-stage renal disease (ESRD).

[A Rapidly Growing Cardiac Calcified Amorphous Tumor in a Peritoneal Dialysis Patient:Report of a Case]

A calcified amorphous tumor( CAT) is a non-neoplastic cardiac tumor, which has been reported to be associated with hemodialysis dependent end-stage renal disease. We report a case of CAT attached to mitral annular calcification (MAC) in the posterior leaflet annulus of the mitral valve in a 56-year-old man who had been receiving peritoneal dialysis for three years. The CAT grew to 10 mm long in a half year. Peritoneal dialysis dependent end-stage renal disease is associated with MAC. Additionally, MAC-related CAT has been reported growing rapidly. We should perform periodic echocardiography not only for hemodialysis patients but also for peritoneal dialysis patients. When CAT is diagnosed, operation should be performed early to prevent embolism such as cerebral infarction.

Crocodile Oil Disrupts Mitochondrial Homeostasis and Exacerbates Diabetic Kidney Injury in Spontaneously Diabetic Torii Rats

Diabetic nephropathy is currently the leading cause of end-stage renal disease (ESRD) in type 2 diabetes. Studies have suggested that supplementation with some fatty acids might reduce the risk and delay the progression to ESRD in patient with chronic kidney disease. Crocodile oil (CO) contains a variety of fatty acids, especially omega-3, -6 and -9, that have been reported to be beneficial to human health. This study examined the impact of long-term CO supplementation on the development of diabetic nephropathy in spontaneously diabetic Torii (SDT) rats. After diabetic verification, SDT rats were assigned to receive vehicle or CO at 500 and 1000 mg/kg BW, respectively, by oral gavage. Age-matched nondiabetic Sprague–Dawley rats were given vehicle or high-dose CO. After 28 weeks of intervention, CO failed to improve hyperglycemia and pancreatic histopathological changes in SDT rats. Unexpectedly, CO dose-dependently exacerbated the impairment of kidney and mitochondrial functions caused by diabetes. CO also disturbed the expressions of proteins involved in mitochondrial biogenesis, dynamics, and mitophagy. However, no significant alterations were observed in nondiabetic rats receiving high-dose CO. The findings reveal that CO has deleterious effects that aggravate diabetic kidney injury via disrupting mitochondrial homeostasis, possibly due to its improper omega-6: omega-3 ratio.

Effects of Uremic Clearance Granules on p38 MAPK/NF-κB Signaling Pathway, Microbial and Metabolic Profiles in End-Stage Renal Disease Rats Receiving Peritoneal Dialysis

Background

Methods

Results

Conclusion

Diabetic Kidney Disease: From Pathogenesis to Novel Treatment Possibilities

One of the microvascular complications of diabetes is diabetic kidney disease (DKD), often leading to end stage renal disease (ESRD) in which patients require costly dialysis or transplantation. The silent onset and irreversible progression of DKD are characterized by a steady decline of the estimated glomerular filtration rate, with or without concomitant albuminuria. The diabetic milieu allows the complex pathophysiology of DKD to enter a vicious cycle by inducing the synthesis of excessive amounts of reactive oxygen species (ROS) causing oxidative stress, inflammation, and fibrosis. As no cure is available, intensive research is required to develop novel treatments possibilities. This chapter provides an overview of the important pathomechanisms identified in diabetic kidney disease, the currently established therapies, as well as recently developed novel therapeutic strategies in DKD.

C3c deposition predicts worse renal outcomes in patients with biopsy-proven diabetic kidney disease in type 2 diabetes mellitus

BACKGROUND

Although extensive efforts have been paid to identify reliable predictors for renal outcomes of diabetic kidney disease (DKD) patients in type 2 diabetes mellitus (T2DM), there are still only a limited number of predictive factors for DKD progression. Increasing evidence reported the role of the overactivated complement system in the pathogenesis of DKD. Whether renal complement depositions are associated with renal outcomes of DKD in T2DM is of interest.

METHODS

A total of 213 biopsy-proven DKD patients with T2DM were retrospectively recruited. Clinical and pathological data of the patients were analyzed. Kaplan-Meier analysis and Cox regression analysis were performed to explore predictors of end-stage renal disease (ESRD).

RESULTS

During a median follow-up of 23.0 (12.0, 39.0) months, 100/213 (46.9%) patients progressed to ESRD. C3c and C1q deposition were observed in 133/213 (62.4%) and 45/213 (21.1%) patients, respectively. Kaplan-Meier analysis revealed patients with C3c or C1q deposition had significantly worse renal outcomes compared with those without C3c or C1q deposition (p = .001 and p < .001, respectively). Univariate and multivariate Cox regression analysis demonstrated proteinuria (per 1 g/24 h increase, hazard ratio [HR] 1.134, 95% confidence interval [CI] [1.079, 1.191], p < .001), interstitial fibrosis and tubular atrophy score (score 2 and 3 vs. 0 and 1, HR 3.925, 95% CI [1.855, 8.304], p < .001), and C3c deposition (per 1+ increase, HR 1.299, 95% CI [1.073, 1.573], p = .007) were independent predictors for ESRD in DKD patients with T2DM.

CONCLUSIONS

C3c deposition in the kidney was associated with worse renal outcomes and was an independent predictor for ESRD in DKD patients with T2DM.

Sarcopenia assessed by 4-step EWGSOP2 in elderly hemodialysis patients: Feasibility and limitations

Background

In 2019, EWGSOP2 proposed 4 steps to diagnose and assess sarcopenia. We aimed to quantify the prevalence of sarcopenia according to the EWGSOP2 diagnostic algorithm and to assess its applicability in elderly patients on hemodialysis.

Methods

Prospective study of 60 outpatients on chronic hemodialysis aged 75- to 95-years, sarcopenia was assessed according to the 4-step EWGSOP2: Find: Strength, Assistance walking, Rise from a chair, Climb stairs, and Falls (SARC-F); Assess: grip strength by dynamometry (GSD) and sit to stand to sit 5 (STS5); Confirm: appendicular skeletal muscle mass (ASM) by bioimpedance; Severity: gait speed (GS), Timed-Up and Go (TUG), and Short Physical Performance Battery (SPPB).

Results

The sequential four steps resulted in a prevalence of confirmed or severe sarcopenia of 20%. Most (97%) patients fulfilled at least one criterion for probable sarcopenia. The sensitivity of SARC-F for confirmed sarcopenia was low (46%). Skipping the SARC-F step increased the prevalence of confirmed and severe sarcopenia to 40% and 37%, respectively. However, 78% of all patients had evidence of dynapenia consistent with severe sarcopenia. Muscle mass (ASM) was normal in 60% of patients, while only 25% had normal muscle strength values (GSD).

Conclusions

According to the 4-step EWGSOP2, the prevalence of confirmed or severe sarcopenia was low in elderly hemodialysis patients. The diagnosis of confirmed sarcopenia underestimated the prevalence of dynapenia consistent with severe sarcopenia. Future studies should address whether a 2-step EWGSOP2 assessment (Assess-Severity) is simpler to apply and may provide better prognostic information than 4-step EWGSOP2 in elderly persons on hemodialysis.

Determinants and Outcomes Associated With Urinary Calcium Excretion in Chronic Kidney Disease

CONTEXT

Abnormalities in calcium metabolism are common in chronic kidney disease (CKD). Diminished urinary calcium excretion may promote vascular calcification and increased urinary calcium excretion may lead to nephrolithiasis and nephrocalcinosis, conditions associated with CKD.

OBJECTIVE

To study predictors of urinary calcium excretion and its association with adverse clinical outcomes in CKD.

DESIGN, SETTING AND PATIENTS

This study assessed 3768 nondialysis participants in the Chronic Renal Insufficiency Cohort study from April 2003 to September 2008. Participants were followed up to October 2018.

EXPOSURE

Clinically plausible predictors of urinary calcium excretion and 24-h urinary calcium excretion at baseline.

MAIN OUTCOME MEASURES

Urinary calcium excretion; incident end stage kidney disease (ESKD), CKD progression [50% estimated glomerular filtration rate (eGFR) decline or incident ESKD], all-cause mortality, and atherosclerotic cardiovascular disease events.

RESULTS

eGFR was positive correlated with 24-h urinary calcium excretion. The variables most strongly associated with 24-h urinary calcium excretion in males and females were 24-h urinary sodium (β = 0.19 and 0.28, respectively), serum parathyroid hormone (β = -0.22 and -0.20, respectively), loop diuretics (β = 0.36 and 0.26, respectively), thiazide diuretics (β = -0.49 and -0.53, respectively), and self-identified black race (β = -0.23 and -0.27, respectively). Lower urinary calcium excretion was associated with greater risks of adverse outcomes, but these associations were greatly attenuated or nullified after adjustment for baseline eGFR.

CONCLUSION

Urinary calcium excretion is markedly lower in individuals with CKD compared to the general population. Determinants of urinary calcium excretion differed between sexes and levels of CKD. Associations between urinary calcium excretion and adverse clinical events were substantially confounded by eGFR.

Juzentaihoto improves adenine-induced chronic renal failure in BALB/c mice via suppression of renal fibrosis and inflammation

Renal inflammation and fibrosis are observed in underlying diseases associated with the pathological progression of chronic kidney disease (CKD). The inhibition of renal inflammation and fibrosis is one method to suppress the progression of CKD. Juzentaihoto (TJ-48), a Kampo medicine, effectively relieves chronic wasting diseases and fatigue and has been reported to decrease inflammation. In this study, we investigated whether TJ-48 has a renal protective effect and its underlying mechanism in mice with adenine-induced CKD. BALB/c mice were divided into four groups for examination: (1) control, (2) dietary restriction, (3) adenine, and (4) adenine + TJ-48. Biochemical and histological analyses, gene expression analysis, and complete blood counts were performed. TJ-48 treatment decreased tubular damage and fibrosis. TJ-48 also decreased creatinine levels exacerbated by adenine, suppressed the mRNA expression of tumor necrosis factor-α, chemokine ligand 2, transforming growth factor-β, and kidney injury molecule-1, and decreased the neutrophil/lymphocyte ratio increased by adenine. TJ-48 exerts a renoprotective effect possibly via the suppression of fibrosis and inflammation.

Metformin improves relevant disease parameters in an autosomal dominant polycystic kidney disease mouse model

Autosomal dominant polycystic kidney disease (ADPKD), caused by mutations in the polycystin 1 (PKD1) or polycystin 2 genes, presents with progressive development of kidney cysts and eventual end-stage kidney disease with limited treatment options. Previous work has shown that metformin reduces cyst growth in rapid ADPKD mouse models via inhibition of cystic fibrosis transmembrane conductance regulator-mediated fluid secretion, mammalian target of rapamycin, and cAMP pathways. The present study importantly tested the effectiveness of metformin as a therapy for ADPKD in a more clinically relevant Pkd1RC/RC mouse model, homozygous for the R3277C knockin point mutation in the Pkd1 gene. This mutation causes ADPKD in humans. Pkd1RC/RC male and female mice, which have a slow progression to end-stage kidney disease, received metformin (300 mg/kg/day in drinking water vs. water alone) from 3 to 9 or 12 mo of age. As previously reported, Pkd1RC/RC females had a more severe disease phenotype as compared with males. Metformin treatment reduced the ratio of total kidney weight-to-body weight relative to age-matched and sex-matched untreated controls at both 9 and 12 mo and reduced the cystic index in females at 9 mo. Metformin also increased glomerular filtration rate, lowered systolic blood pressure, improved anemia, and lowered blood urea nitrogen levels relative to controls in both sexes. Moreover, metformin reduced gene expression of key inflammatory markers and both gene and protein expression of kidney injury marker-1 and cyclin-dependent kinase-1 versus untreated controls. Altogether, these findings suggest several beneficial effects of metformin in this highly relevant slowly progressive ADPKD mouse model, which may help inform new ADPKD therapies in patients.NEW & NOTEWORTHY Metformin treatment improved ADPKD disease severity in a relevant, slowly progressive ADPKD mouse model that recapitulates a PKD-associated PKD1 mutation. Relative to controls, metformin reduced kidney weight/body weight, cystic index and BUN levels, while improving GFR, blood pressure and anemia. Metformin also reduced key inflammatory and injury markers, along with cell proliferation markers. These findings suggest several beneficial effects of metformin in this ADPKD mouse model, which may help inform new ADPKD therapies in patients.

Research advance in the mechanism for oxidative stress-induced podocyte injury in diabetic kidney disease

Diabetic kidney disease (DKD) is one of the serious microvascular complications of diabetes mellitus (DM), and it is also the leading cause for the end-stage kidney disease (ESKD), but the clinical treatment for it is limited at present. The pathogenesis of DKD is complex. Many studies have shown that podocyte injury is the core event of DKD, and oxidative stress is closely related to podocyte injury in DKD. Oxidative stress mediates podocyte apoptosis and slit diaphragm damage in DKD through various pathways. The antioxidant drugs can slow down the progression of DKD through reducing podocyte injury and are expected to enter clinical trials. The research status of antioxidant drugs is very important, which will provide new strategies for the clinical treatment of DKD.

Liver cirrhosis with encapsulating peritoneal sclerosis after 4 years of peritoneal dialysis: A case report

RATIONALE

Encapsulating peritoneal sclerosis (EPS), or abdominal cocoon, is a rare but fatal syndrome characterized by intestinal obstruction owing to adhesions in a diffusely thickened peritoneum. Long-term peritoneal dialysis (PD) for more than 5 years is commonly associated with EPS, while liver cirrhosis also carries a risk of EPS. However, there have been only a few reports that describe a case of EPS complicated with both cirrhosis and PD. We herein describe a case of advanced liver cirrhosis with end-stage renal disease (ESRD) who developed EPS after 4 years of PD and who was successfully recovered by surgery.

PATIENT CONCERNS

A 58-year-old man with alcoholic liver cirrhosis suffered abdominal pain. The patient had a 4-year history of continuous cycling PD to manage ESRD as well as cirrhotic complications of refractory ascites and hypotension. Laboratory test results showed increased levels of inflammation, and contrast-enhanced computed tomography scan showed dilated loops of small bowel proximal to the site of intestinal obstruction. The patient was suspected to have developed intestinal obstruction owing to EPS. The patient discontinued continuous cycling peritoneal dialysis and switched to hemodiafiltration.

DIAGNOSES

Laparoscopy revealed a whitish membranous material wrapped around the bowel, especially at the terminal ileum with a narrowed portion, consistent with EPS.

INTERVENTIONS

Repeated decortication of fibrous peritoneal membranes successfully released the intestinal obstruction.

OUTCOMES

The postoperative course went well and abdominal pain remained in remission. Because abdominal distension owing to ascites got intolerable in a few days after surgery, a PD catheter was re-inserted and ascitic fluid drainage was resumed with peritoneal lavage. The patient continued hemodiafiltration using vasopressor agents.

LESSONS

The Cirrhotic patient with ESRD undergoing PD could develop EPS after a short duration of PD.

Peritoneal transport status and first episode of peritonitis: a large cohort study

BACKGROUND

Peritonitis is one of the most serious complications of peritoneal dialysis (PD). This study aimed to explore the relationship between peritoneal transport status and the first episode of peritonitis, as well as the prognosis of patients undergoing continuous ambulatory peritoneal dialysis (CAPD).

METHOD

A retrospective cohort study was conducted, analyzing data of CAPD patients from 1st January 2009, to 31st December 2017. Baseline data within 3 months after PD catheter placement was recorded. Cox multivariate regression analysis was performed to determine the risk factors for the first episode of peritonitis, technique failure and overall mortality.

RESULTS

A total of 591 patients were included in our analysis, with a mean follow-up visit of 49 months (range: 27-75months). There were 174 (29.4%) patients who had experienced at least one episode of peritonitis. Multivariate Cox regression analysis revealed that a higher peritoneal transport status (high and high-average) (HR 1.872, 95%CI 1.349-2.599, p = 0.006) and hypoalbuminemia (HR 0.932,95% CI 0.896, 0.969, p = 0.004) were independent risk factors for the occurrence of the first episode of peritonitis. In addition, factors including gender (male) (HR 1.409, 95%CI 1.103, 1.800, p = 0.010), low serum albumin (HR 0.965, 95%CI 0.938, 0.993, p = 0.015) and the place of residence (rural) (HR 1.324, 95%CI 1.037, 1.691, p = 0.024) were independent predictors of technique failure. Furthermore, low serum albumin levels (HR 0.938, 95%CI 0.895, 0.984, p = 0.008) and age (>65years) (HR 1.059, 95%CI 1.042, 1.076, p < 0.001) were significantly associated with the risk of overall mortality of PD patients.

CONCLUSIONS

Baseline hypoalbuminemia and a higher peritoneal transport status are risk factors for the first episode of peritonitis. Factors including male gender, hypoalbuminemia, and residing in rural areas are associated with technique failure, while hypoalbuminemia and age (>65years) are predictors of the overall mortality in PD patients. Nevertheless, the peritoneal transport status does not predict technique failure or overall mortality of PD patients.

Burden of kidney disease on the discrepancy between reasons for hospital admission and death: An observational cohort study

Background

Physicians have long noted a substantial discrepancy between the reasons for hospital admission and ultimate causes of death, particularly among older adults or patients with complex underlying diseases. However, objective data on this phenomenon are lacking. We aimed to examine the risk of in-hospital death caused by a reason other than the original reason for hospitalization and its association with underlying kidney disease in a nationwide inpatient database.

Methods

In this retrospective cohort study, we studied 639,556 Japanese adults who died in the hospital from 2012 to 2015, using data from Japan’s Diagnosis Procedure Combination database. We analyzed the discrepancy rate between reasons for hospital admission and death and associated factors using the International Classification of Diseases, 10th Revision (ICD-10) diagnostic codes and seven related categories.

Results

Among non-chronic kidney disease (CKD) (590,551), CKD (24,708), and end-stage kidney disease (ESKD) (24,297) patients, the median age was 77 years (interquartile range [IQR]: 67–84 years), 83 years (IQR: 75–88), and 75 years (IQR: 67–81), and 25.7%, 30.3%, and 41.6% died from a reason other than the original reason for hospitalization, respectively. Multivariate logistic regression analyses determined CKD/ESKD as the predominant risk factor for this discrepancy, rather than older age, male sex, obesity, and other comorbidities. Sankey diagrams that presented diagnostic changes from hospital admission to death revealed multiple wider segments connecting to different disease classifications, particularly to congestive and septic death in CKD and ESKD patients, respectively. Death owing to another disease classification led to an increase in the median length of hospital stay by 5–7 days and to a 1.3-–1.4-fold increase in medical costs across the populations.

Conclusions

A substantial proportion of patients with CKD and ESKD died during hospitalization for a reason other than their original reason for admission, leading to increased length of hospital stay and cost.

Effects of calcitriol on peripheral endothelial progenitor cells and renal renovation in rats with chronic renal failure

BACKGROUND

The role of calcitriol (1,25-dihydroxyvitamin D₃ or 1,25-(OH)₂D₃) in physiological processes, such as anti-fibrosis, anti-inflammation, and immunoregulation is known; however, its role in the remodeling of the glomerular capillary endothelium in rats with chronic renal failure (CRF) remains unclear.

METHODS

Here, we analyzed the role/number of endothelial progenitor cells (EPCs), renal function, and pathological alterations in rats with CRF, and compared the results before and after supplementation with calcitriol in vivo.

RESULTS

Amongst the three experimental groups (sham group, CRF group, and calcitriol-treated group (0.03 μg/kg/d), we observed substantially elevated cell adhesion and vasculogenesis in vivo in the calcitriol-treated group. Additionally, lower levels of serum creatinine (Scr) and blood urea nitrogen (BUN) was recorded in the calcitriol-treated group than the CRF group (p > 0.05). Calcitriol treatment also resulted in an improvement in renal pathological injury.

CONCLUSIONS

Thus, calcitriol could ameliorate the damage of glomerular arterial structural and renal tubules vascular network integrity, maybe through regulating the number and function of EPCs in the peripheral blood of CRF rats. Treatment with it may improve outcomes in patients with renal insufficiency or combined cardiac insufficiency. Calcitriol could ameliorate CRF-induced renal pathological injury and renal dysfunction by remodeling of the glomerular capillary endothelium, thus, improving the function of glomerular endothelial cells.

Successful High-dose Chemotherapy in Combination With Autologous Peripheral Blood Stem Cell Transplantation in an Anuric Child With Neuroblastoma

No reports describe high-dose chemotherapy (HDCT) with autologous peripheral blood stem cell transplantation (auto-PBSCT) in pediatric patients with neuroblastoma and end-stage renal disease. Here, we report the case of a patient with high-risk neuroblastoma who developed anuria during treatment. HDCT with auto-PBSCT under hemodialysis, with strict attention to the ultrafiltration volume and dose modification of alkylating agents, was performed. Although the first auto-PBSCT led to engraftment failure, the second auto-PBSCT resulted in successful myeloid engraftment 8 months after anuria. This case demonstrated that HDCT with auto-PBSCT can be safely performed in children with renal failure under hemodialysis.

The Pathogenesis of End-Stage Renal Disease from the Standpoint of the Theory of General Pathological Processes of Inflammation

Chronic kidney disease can progress to end-stage chronic renal disease (ESRD), which requires the use of replacement therapy (dialysis or kidney transplant) in life-threatening conditions. In ESRD, irreversible changes in the kidneys are associated with systemic changes of proinflammatory nature and dysfunctions of internal organs, skeletal muscles, and integumentary tissues. The common components of ESRD pathogenesis, regardless of the initial nosology, are (1) local (in the kidneys) and systemic chronic low-grade inflammation (ChLGI) as a risk factor for diabetic kidney disease and its progression to ESRD, (2) inflammation of the classical type characteristic of primary and secondary autoimmune glomerulonephritis and infectious recurrent pyelonephritis, as well as immune reactions in kidney allograft rejection, and (3) chronic systemic inflammation (ChSI), pathogenetically characterized by latent microcirculatory disorders and manifestations of paracoagulation. The development of ChSI is closely associated with programmed hemodialysis in ESRD, as well as with the systemic autoimmune process. Consideration of ESRD pathogenesis from the standpoint of the theory of general pathological processes opens up the scope not only for particular but also for universal approaches to conducting pathogenetic therapies and diagnosing and predicting systemic complications in severe nephropathies.

Projection of the health and economic impacts of Chronic kidney disease in the Chilean population

BACKGROUND

Chronic Kidney Disease (CKD) is a leading public health problem, with substantial burden and economic implications for healthcare systems, mainly due to renal replacement treatment (RRT) for end-stage kidney disease (ESKD). The aim of this study is to develop a multistate predictive model to estimate the future burden of CKD in Chile, given the high and rising RRT rates, population ageing, and prevalence of comorbidities contributing to CKD.

METHODS

A dynamic stock and flow model was developed to simulate CKD progression in the Chilean population aged 40 years and older, up to the year 2041, adopting the perspective of the Chilean public healthcare system. The model included six states replicating progression of CKD, which was assumed in 1-year cycles and was categorised as slow, medium or fast progression, based on the underlying conditions. We simulated two different treatment scenarios. Only direct costs of treatment were included, and a 3% per year discount rate was applied after the first year. We calibrated the model based on international evidence; the exploration of uncertainty (95% credibility intervals) was undertaken with probabilistic sensitivity analysis.

RESULTS

By the year 2041, there is an expected increase in cases of CKD stages 3a to ESKD, ceteris paribus, from 442,265 (95% UI 441,808-442,722) in 2021 to 735,513 (734,455-736,570) individuals. Direct costs of CKD stages 3a to ESKD would rise from 322.4M GBP (321.7-323.1) in 2021 to 1,038.6M GBP (1,035.5-1,041.8) in 2041. A reduction in the progression rates of the disease by the inclusion of SGLT2 inhibitors and pre-dialysis treatment would decrease the number of individuals worsening to stages 5 and ESKD, thus reducing the total costs of CKD by 214.6M GBP in 2041 to 824.0M GBP (822.7-825.3).

CONCLUSIONS

This model can be a useful tool for healthcare planning, with development of preventive or treatment plans to reduce and delay the progression of the disease and thus the anticipated increase in the healthcare costs of CKD.

Efficacy of tacrolimus as maintenance therapy after cyclophosphamide for treating antineutrophil cytoplasmic antibody-associated vasculitis

Azathioprine (AZA), methotrexate, or rituximab is used for the maintenance therapy of antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Although the efficacy of tacrolimus (TAC) in various autoimmune diseases has been demonstrated, there have been few reports on the efficacy of TAC in AAV. We investigated the efficacy of TAC as maintenance therapy for AAV and compared its efficacy with that of AZA.We retrospectively analyzed the medical records of 81 patients with AAV who received cyclophosphamide as induction therapy and AZA or TAC as maintenance therapy. All-cause death, relapse, and progression to end-stage renal disease (ESRD) were analyzed.Among 81 patients with AAV, 69 patients received AZA alone, 6 patients received TAC alone, and 6 patients received TAC after AZA for maintenance therapy. Overall, 11 patients (13.6%) died, 30 patients (37.0%) experienced relapse, and 16 patients (19.8%) progressed to ESRD during a median of 33.8 months. No significant differences were observed in cumulative patients', relapse-free, and ESRD-free survival rates between patients administered AZA alone and TAC alone. There were no significant differences in the cumulative patients' and relapse-free survival rate between patients who received AZA alone and TAC after AZA. However, the cumulative ESRD-free survival rate was lower in patients who received TAC after AZA than in those who received AZA alone (P = .027).Patients who received TAC as maintenance therapy showed a higher incidence of ESRD than those who received AZA; however, this might be attributed to the lack of efficacy of AZA rather than the low ESRD prevention effect of TAC.

Potency of propofol for inducing loss of consciousness in end-stage kidney disease patients

It can be difficult for anesthesiologists to determine the optimal dose of propofol for end-stage kidney disease (ESKD) patients due to changes in drug disposition. The purpose of this study was to evaluate the potency of propofol for inducing loss of consciousness in ESKD patients. Patients with normal kidney function (Control group, n = 15), those with ESKD (ESKD group, n = 15), and those with ESKD undergoing cervical epidural anesthesia (ESKD-CEB group, n = 15) were administered propofol by target-controlled infusion (TCI) using the Schneider model. The effect-site concentration (Ce) of propofol started at 0.5 μg/ml and increased in increments of 0.5 μg/ml until the patient did not respond to verbal commands. The relationship between the probability (P) of loss of consciousness and the Ce of propofol was analyzed in each group using logistic regression. The Ce values of propofol at the time of loss of consciousness were 4.3 ± 0.9, 3.7 ± 0.9, and 3.3 ± 1.0 μg/ml for the Control, ESKD, and ESKD-CEB* groups, respectively (*significant difference vs. control, P < 0.05). The estimated Ce50 values for lost ability to respond to verbal command were 4.56, 3.75, and 3.21 μg/ml for the Control, ESKD, and ESKD-CEB groups, respectively. In conclusion, when inducing anesthesia in ESKD patients, we recommend using an initial dose similar to that of patients with normal kidney function, or rather starting with a lower dose.

Good practices for dialysis education, treatment, and eHealth: A scoping review

BACKGROUND

Recommendations regarding dialysis education and treatment are provided in various (inter)national guidelines, which should ensure that these are applied uniformly in nephrology and dialysis centers. However, there is much practice variation which could be explained by good practices: practices developed by local health care professionals, which are not evidence-based. Because an overview of good practices is lacking, we performed a scoping review to identify and summarize the available good practices for dialysis education, treatment, and eHealth.

METHODS

Embase, Pubmed, the Cochrane Library, CINAHL databases and Web of Science were searched for relevant articles using all synonyms for the words 'kidney failure', 'dialysis', and 'good practice'. Relevant articles were structured according to the categories dialysis education, dialysis treatment or eHealth, and assessed for content and results.

RESULTS

Nineteen articles (12 for dialysis education, 3 for dialysis treatment, 4 for eHealth) are identified. The good practices for education endorse the importance of providing complete and objective predialysis education, assisting peritoneal dialysis (PD) patients in adequately performing PD, educating hemodialysis (HD) patients on self-management, and talking with dialysis patients about their prognosis. The good practices for dialysis treatment focus mainly on dialysis access devices and general quality improvement of dialysis care. Finally, eHealth is useful for HD and PD and affects both quality of care and health-related quality of life.

CONCLUSION

Our scoping review identifies 19 articles describing good practices and their results for dialysis education, dialysis treatment, and eHealth. These good practices could be valuable in addition to guidelines for increasing shared-decision making in predialysis education, using patients' contribution in the implementation of their dialysis treatment, and advanced care planning.

Prognostic Factors and Long-Term Outcome with ANCA-Associated Kidney Vasculitis in Childhood

BACKGROUND AND OBJECTIVES

ANCA-associated vasculitis is extremely rare in children. We report the clinicopathologic features, long-term outcomes, and prognostic factors of a large pediatric cohort of patients with ANCA-associated kidney vasculitis.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

This retrospective study included 85 consecutive patients with kidney biopsy specimen-proven ANCA-associated vasculitis from tertiary referral centers in Italy and Canada. Kidney biopsy specimens were categorized as focal, crescentic, sclerotic, or mixed, according to the Berden classification. The prognostic significance of baseline clinical, laboratory, and histologic findings was analyzed with respect to kidney failure or CKD stage 3-5/kidney failure.

RESULTS

A total of 53 patients had microscopic polyangiitis (62%), and 32 had granulomatosis with polyangiitis (38%). Rapidly progressive GN was the most frequent presentation (39%); a third of the patients also had nephrotic-range proteinuria. Kidney biopsy specimens were classified as focal in 21% of the patients, crescentic in 51%, sclerotic in 15%, and mixed in 13%. Remission-induction therapies included cyclophosphamide in 78% of patients. A total of 25 patients (29%) reached kidney failure. The median (interquartile range) time to kidney failure or last follow-up was 35 (6-89) months in the whole cohort, and 73 (24-109) months among the patients who did not reach this outcome. Patients whose biopsy specimens showed sclerotic histology had significantly shorter kidney survival (hazard ratio, 11.80; 95% confidence interval, 2.49 to 55.99) and survival free of CKD stage 3-5 (hazard ratio, 8.88; 95% confidence interval, 2.43 to 32.48), as compared with those with focal/mixed histology. Baseline eGFR, low serum albumin, hypertension, central nervous system complications, and sclerotic histology, which reflected severe kidney involvement, were associated with both kidney failure and CKD stage 3-5/kidney failure at unadjusted analysis; no independent prognostic factors emerged at multivariable analysis.

CONCLUSIONS

Children with ANCA-associated kidney vasculitis often have aggressive presentation; a third of such children progress to kidney failure and this usually occurs early during follow-up. A severe clinical presentation is associated with the development of CKD or kidney failure.

Types of erythropoiesis-stimulating agents and risk of end-stage kidney disease and death in patients with non-dialysis chronic kidney disease

BACKGROUND

Despite the widespread use of erythropoiesis-stimulating agents (ESAs) to treat anaemia, the risk of adverse outcomes associated with the use of different types of ESAs in non-dialysis chronic kidney disease (CKD) is poorly investigated.

METHODS

From a pooled cohort of four observational studies, we selected CKD patients receiving short-acting (epoetin α/β; n = 299) or long-acting ESAs (darbepoetin and methoxy polyethylene glycol-epoetin β; n = 403). The primary composite endpoint was end-stage kidney disease (ESKD; dialysis or transplantation) or all-cause death. Multivariable Cox models were used to estimate the relative risk of the primary endpoint between short- and long-acting ESA users.

RESULTS

During follow-up [median 3.6 years (interquartile range 2.1-6.3)], the primary endpoint was registered in 401 patients [166 (72%) in the short-acting ESA group and 235 (58%) in the long-acting ESA group]. In the highest tertile of short-acting ESA dose, the adjusted risk of primary endpoint was 2-fold higher {hazard ratio [HR] 2.07 [95% confidence interval (CI) 1.37-3.12]} than in the lowest tertile, whereas it did not change across tertiles of dose for long-acting ESA patients. Furthermore, the comparison of ESA type in each tertile of ESA dose disclosed a significant difference only in the highest tertile, where the risk of the primary endpoint was significantly higher in patients receiving short-acting ESAs [HR 1.56 (95% CI 1.09-2.24); P = 0.016]. Results were confirmed when ESA dose was analysed as continuous variable with a significant difference in the primary endpoint between short- and long-acting ESAs for doses >105 IU/kg/week.

CONCLUSIONS

Among non-dialysis CKD patients, the use of a short-acting ESA may be associated with an increased risk of ESKD or death versus long-acting ESAs when higher ESA doses are prescribed.

A novel approach to dry weight adjustments for dialysis patients using machine learning

Background and aims

Knowledge of the proper dry weight plays a critical role in the efficiency of dialysis and the survival of hemodialysis patients. Recently, bioimpedance spectroscopy(BIS) has been widely used for set dry weight in hemodialysis patients. However, BIS is often misrepresented in clinical healthy weight. In this study, we tried to predict the clinically proper dry weight (DW_CP) using machine learning for patient’s clinical information including BIS. We then analyze the factors that influence the prediction of the clinical dry weight.

Methods

As a retrospective, single center study, data of 1672 hemodialysis patients were reviewed. DW_CP data were collected when the dry weight was measured using the BIS (DW_BIS). The gap between the two (Gap_DW) was calculated and then grouped and analyzed based on gaps of 1 kg and 2 kg.

Results

Based on the gap between DW_BIS and DW_CP, 972, 303, and 384 patients were placed in groups with gaps of <1 kg, ≧1kg and <2 kg, and ≧2 kg, respectively. For less than 1 kg and 2 kg of GapDW, It can be seen that the average accuracies for the two groups are 83% and 72%, respectively, in usign XGBoost machine learning. As Gap_DW increases, it is more difficult to predict the target property. As Gap_DW increase, the mean values of hemoglobin, total protein, serum albumin, creatinine, phosphorus, potassium, and the fat tissue index tended to decrease. However, the height, total body water, extracellular water (ECW), and ECW to intracellular water ratio tended to increase.

Conclusions

Machine learning made it slightly easier to predict DW_CP based on DW_BIS under limited conditions and gave better insights into predicting DW_CP. Malnutrition-related factors and ECW were important in reflecting the differences between DW_BIS and DW_CP.

Correlation between serum carnosinase concentration and renal damage in diabetic nephropathy patients

Diabetic nephropathy (DN) is one of the major complications of diabetes and contributes significantly towards end-stage renal disease. Previous studies have identified the gene encoding carnosinase (CN-1) as a predisposing factor for DN. Despite this fact, the relationship of the level of serum CN-1 and the progression of DN remains uninvestigated. Thus, the proposed study focused on clarifying the relationship among serum CN-1, indicators of renal function and tissue injury, and the progression of DN. A total of 14 patients with minimal changes disease (MCD) and 37 patients with DN were enrolled in the study. Additionally, 20 healthy volunteers were recruited as control. Further, DN patients were classified according to urinary albumin excretion rate into two groups: DN with microalbuminuria (n = 11) and DN with macroalbuminuria (n = 26). Clinical indicators including urinary protein components, serum carnosine concentration, serum CN-1 concentration and activity, and renal biopsy tissue injury indexes were included for analyzation. The serum CN-1 concentration and activity were observed to be the highest, but the serum carnosine concentration was the lowest in DN macroalbuminuria group. Moreover, within DN group, the concentration of serum CN-1 was positively correlated with uric acid (UA, r = 0.376, p = 0.026) and serum creatinine (SCr, r = 0.399, p = 0.018) and negatively correlated with serum albumin (Alb, r = − 0.348, p = 0.041) and estimated glomerular filtration rate (eGRF, r = − 0.432, p = 0.010). Furthermore, the concentration of serum CN-1 was discovered to be positively correlated with indicators including 24-h urinary protein–creatinine ratio (24 h-U-PRO/CRE, r = 0.528, p = 0.001), urinary albumin-to-creatinine ratio (Alb/CRE, r = 0.671, p = 0.000), urinary transferrin (TRF, r = 0.658, p = 0.000), retinol-binding protein (RBP, r = 0.523, p = 0.001), N-acetyl-glycosaminidase (NAG, r = 0.381, p = 0.024), immunoglobulin G (IgG, r = 0.522, p = 0.001), cystatin C (Cys-C, r = 0.539, p = 0.001), beta-2-microglobulin (β2-MG, r = 0.437, p = 0.009), and alpha-1-macroglobulin (α1-MG, r = 0.480, p = 0.004). Besides, in DN with macroalbuminuria group, serum CN-1 also showed a positive correlation with indicators of fibrosis, oxidative stress, and renal tubular injury. Taken together, our data suggested that the level of CN-1 was increased as clinical DN progressed. Thus, the level of serum CN-1 might be an important character during the occurrence and progression of DN. Our study will contribute significantly to future studies focused on dissecting the underlying mechanism of DN.

Association of overhydration and serum pigment epithelium-derived factor with CKD progression in diabetic kidney disease: A prospective cohort study

AIM

Little is known about whether overhydration (OH), measured using bioimpedance assay (BIA), is associated with CKD progression in patients with type 2 diabetes mellitus (T2DM). We hypothesised that OH was a predictor, and pigment epithelium-derived factor (PEDF) was a modifiable risk factor of CKD progression.

METHODS

We conducted a prospective cohort study of 1,065 patients with clinically euvolemic T2DM who attended the diabetes centre in a tertiary hospital or primary care clinic. CKD progression was defined as a combination of the worsening of the KDIGO defined CKD category by eGFR and a ≥25% decline in eGFR compared to baseline.

RESULTS

Patients with T2DM in the highest tertile of OH and relative OH (OH/ extracellular water > 7%) were positively associated with CKD progression (hazard ratio [HR] 1.45 [95% confidence interval (CI) 1.14-1.85; p = 0.003 and HR 1.29 [95%CI 1.05-1.59; p = 0.017]). There were positive associations between PEDF and CKD progression (β = 1.10; p = 0.001) and between OH and CKD progression (β = 0.21; p = 0.036). OH remained positively associated with CKD progression mediated by PEDF.

CONCLUSIONS

OH is an independent risk factor for CKD progression in patients with T2DM. Our study supports the novel definition of PEDF as a positive mediator between OH and CKD progression.

Fibrosis-5 predicts end-stage renal disease in patients with microscopic polyangiitis and granulomatosis with polyangiitis without substantial liver diseases

We previously reported that fibrosis-4 (FIB-4) was associated with poor outcomes of microscopic polyangiitis (MPA) and granuloma with polyangiitis (GPA). We also investigated the potential of FIB-5, a novel index, in predicting all-cause mortality and end-stage renal disease (ESRD) during follow-up in patients with MPA and GPA without substantial liver diseases. Clinical and laboratory data at diagnosis were collected by reviewing the medical records of 180 patients with MPA and GPA. FIB-5 was obtained by a following equation: FIB-5 = (serum albumin (g/L) × 0.3 + platelet count (10⁹/L) × 0.05) − (alkaline phosphatase (IU/L) × 0.014 + aspartate aminotransferase/alanine aminotransferase ratio × 6 + 14). The median age of the patients at diagnosis was 61.0 years. FIB-5 at diagnosis could not reflect the cross-sectional vasculitis activity. The cutoffs of FIB-5 for poor outcomes was set as 0.82 (the lowest tertile) and -0.42 (the lowest quartile) at diagnosis. In Kaplan–Meier survival analysis, patients with FIB-5 < 0.82 and those with FIB-5 < -0.42 exhibited lower ESRD-free survival rates than those without. However, it could not predict all-cause mortality. In multivariable Cox hazards analysis, both FFS (Hazard ratio (HR) 1.554) and FIB-5 < 0.82 (HR 2.096) as well as both FFS (HR 1.534) and FIB-5 < -0.42 (HR 2.073) at diagnosis independently predicted ESRD during follow-up. In conclusion, FIB-5 < 0.82 and FIB-5 < -0.42 at diagnosis could predict the occurrence of ESRD, but not all-cause mortality, during follow-up in patients with MPA and GPA without substantial liver diseases.

Validation of prognostic indices for short term mortality in an incident dialysis population of older adults >75

Rational and objective

Prognosis provides critical knowledge for shared decision making between patients and clinicians. While several prognostic indices for mortality in dialysis patients have been developed, their performance among elderly patients initiating dialysis is unknown, despite great need for reliable prognostication in that context. To assess the performance of 6 previously validated prognostic indices to predict 3 and/or 6 months mortality in a cohort of elderly incident dialysis patients.

Study design

Validation study of prognostic indices using retrospective cohort data. Indices were compared using the concordance (“c”)-statistic, i.e. area under the receiver operating characteristic curve (ROC). Calibration, sensitivity, specificity, positive and negative predictive values were also calculated.

Setting & participants

Incident elderly (age ≥75 years; n = 349) dialysis patients at a tertiary referral center.

Established predictors

Variables for six validated prognostic indices for short term (3 and 6 month) mortality prediction (Foley, NCI, REIN, updated REIN, Thamer, and Wick) were extracted from the electronic medical record. The indices were individually applied as per each index specifications to predict 3- and/or 6-month mortality.

Results

In our cohort of 349 patients, mean age was 81.5±4.4 years, 66% were male, and median survival was 351 days. The c-statistic for the risk prediction indices ranged from 0.57 to 0.73. Wick ROC 0.73 (0.68, 0.78) and Foley 0.67 (0.61, 0.73) indices performed best. The Foley index was weakly calibrated with poor overall model fit (p <0.01) and overestimated mortality risk, while the Wick index was relatively well-calibrated but underestimated mortality risk.

Limitations

Small sample size, use of secondary data, need for imputation, homogeneous population.

Conclusion

Most predictive indices for mortality performed moderately in our incident dialysis population. The Wick and Foley indices were the best performing, but had issues with under and over calibration. More accurate indices for predicting survival in older patients with kidney failure are needed.

Clinical and Pathological Characteristics of Patients With Nonproteinuric Diabetic Nephropathy

INTRODUCTION

As the most common complication of diabetes mellitus (DM), diabetic nephropathy (DN) was initially considered to begin with proteinuria preceding the progression of renal insufficiency. This clinical paradigm has been questioned in the late decades, as many DM patients without proteinuria have progressive renal insufficiency. However, the characteristics of nonproteinuric DN were not fully clear yet.

PATIENTS AND METHODS

A total of 390 patients with renal biopsy-proven DN in our center were retrospectively recruited in the current study. Clinical and histopathological data of the patients were analyzed. We used propensity score-matching methods to address the imbalance of age, sex, and diabetes duration for comparative analyses.

RESULTS

Among all the renal biopsy-proven DN patients with renal biopsy proven DN, 18 patients were classified as nonproteinuric DN. Compared with 36 propensity score-matched proteinuric DN patients, diabetic retinopathy (DR) was less frequent in nonproteinuric DN patients (38.9% vs. 66.4%, p<0.05). During the follow-up of 24.0 (12.0-42.0) months, the probability of developing the end-stage renal disease (ESRD) was significantly lower in nonproteinuric DN patients than in proteinuric ones in both the propensity score-matched cohort and overall cohort (log-rank test, p<0.001 and p<0.001, respectively).

CONCLUSIONS

Compared with proteinuric DN patients, DR was less frequent in nonproteinuric DN patients. Nonproteinuric DN patients had better renal outcomes than proteinuric DN patients.