Cause Of Chronic Kidney Disease Research Articles

Advancements in diabetic kidney disease management: integrating innovative therapies and targeted drug development.

Diabetic kidney disease (DKD) is a leading cause of chronic kidney disease and affects approximately 40% of individuals with diabetes . Cases of DKD continue to rise globally as the prevalence of diabetes mellitus increases, with an estimated 415 million people living with diabetes in 2015 and a projected 642 million by 2040. DKD is associated with significant morbidity and mortality, representing 34% and 36% of all chronic kidney disease deaths in men and women, respectively. Common comorbidities including hypertension and ageing-related nephron loss further complicate disease diagnosis and progression. The progression of DKD involves several mechanisms including glomerular endothelial cell dysfunction, inflammation, and fibrosis. Targeting these mechanisms has formed the basis of several therapeutic agents. Renin-angiotensin-aldosterone system (RAAS) blockers, specifically angiotensin receptor blockers (ARBs), demonstrate significant reductions in macroalbuminuria. Sodium-glucose transporter type 2 (SGLT-2) inhibitors demonstrate kidney protection independent of diabetes control while also decreasing the incidence of cardiovascular events. Emerging agents including glucagon-like peptide 1 (GLP-1) agonists, anti-inflammatory agents like bardoxolone, and mineralocorticoid receptor antagonists show promise in mitigating DKD progression. Many novel therapies including monoclonal antibodies CSL346, lixudebart, and tozorakimab; mesenchymal stem/stromal cell infusion; and cannabinoid-1 receptor inverse agonism via INV-202 are currently in clinical trials and present opportunities for further drug development.

Isocitrate dehydrogenase 1 upregulation in urinary extracellular vesicles from proximal tubules of type 2 diabetic rats.

Diabetic nephropathy (DN) is a major cause of chronic kidney disease. Microalbuminuria is currently the most common non-invasive biomarker for the early diagnosis of DN. However, renal structural damage may have advanced when albuminuria is detected. In this study, we sought biomarkers for early DN diagnosis through proteomic analysis of urinary extracellular vesicles (uEVs) from type 2 diabetic model rats and normal controls. Isocitrate dehydrogenase 1 (IDH1) was significantly increased in uEVs from diabetic model rats at the early stage despite minimal differences in albuminuria between the groups. Calorie restriction significantly suppressed the increase in IDH1 in uEVs and 24-hour urinary albumin excretion, suggesting that the increase in IDH1 in uEVs was associated with the progression of DN. Additionally, we investigated the origin of IDH1-containing uEVs based on their surface sugar chains. Lectin affinity enrichment and immunohistochemical staining showed that IDH1-containing uEVs were derived from proximal tubules. These findings suggest that the increase in IDH1 in uEVs reflects pathophysiological alterations in the proximal tubules and that IDH1 in uEVs may serve as a potential biomarker of DN in the proximal tubules.

#814 Inflammatory biomarkers and progression of diabetic kidney disease

Abstract Background and Aims Diabetic kidney disease (DKD) is one of the fastest growing causes of chronic kidney disease and associated morbidity and mortality. Previous studies have demonstrated the involvement of inflammation in the progression of kidney damage. The aim of our study was to evaluate potential therapeutic approaches using inflammatory biomarkers to assess DKD progression. Method A total of 499 patients with DT1 and DT2, aged 34 to 84 years (60 [60;72]), were examined. All patients underwent standard clinical and laboratory examination, with an assessment of the levels of the inflammatory biomarkers (FGF-23, TNF-α, VEGF-A, hsCRP, Il-6) in baseline plasma samples. Renal function was assessed based on the levels of serum creatinine, eGFR and albumin/creatinine ratio. Control group included 65 people the same age without diabetes. Results We divided all patients into two groups according to the presence DKD. The levels of FGF-23 (p < 0.001), TNF-α (p = 0.014), VEGF-A (p = 0.006), hsCRP (p < 0.001), Il-6 (p < 0.001) were significantly higher in patients with DKD than in control group. A predictive model was developed to estimate the probability of DKD depending on VEGF-A, FGF-23, TNF-α, Il-6, hsCRP, age, duration of diabetes, systolic blood pressure, HbA1c, LDL-C, using binary logistic regression. The resulting regression model was statistically significant (p < 0.001). Based on the value of Nagelkerke R², the model explained 79.5% of the observed DKD variance. 1 pmol/l increase of FGF-23 was associated with 1.921 times increase in DKD odds. 1 pg/ml increase of TNF-α was associated with 1.092 times decrease in DKD odds. 1 mg/ml increase of Il-6 was associated with 1.612 times increase in DKD odds. 1 mg/l increase of hsCRP was associated with 1.496 times increase in DKD odds. Conclusion Our study identifies FGF-23, TNF-α, Il-6, hsCRP as promising targets of novel therapeutic interventions in patients with diabetes, which should be investigated in future clinical trials.

#771 Estimating glomerular filtration rate: does the diabetic status influence the performances of current equations?

Abstract Background and Aims Diabetes is the first cause of chronic kidney disease (CKD) worldwide. The estimation of glomerular filtration rate (GFR) is one main tool to detect CKD. The most used biomarker remains serum creatinine and the European Kidney Function Consortium (EKFCcrea) equations is the most validated in Europe. More recently, another renal biomarker, cystatin C, has been proposed. In the current analysis, we studied the performances of the EKFC equations in a large cohort of subjects according to their diabetic status. Method Four cohorts from the EKFC dataset were considered in which the diabetic status was available: Lund, Sweden (n = 2,780), Berlin, Germany (n = 654), Créteil, France (n = 466), and Paris, France (n = 2,258). Serum creatinine and cystatin C were measured with calibrated assays. GFR was measured by plasma clearances (mGFR) (iohexol in Lund, Berlin and Créteil and 51Cr-EDTA in Paris). The performance of the equations was assessed by calculating bias, precision (IQR) and P30 (percentage of eGFR-values within ±30% of mGFR). As the characteristics of diabetic patients were different, we matched diabetic and non-diabetic patients using the following matching criteria: age (±3 years), sex (equal), mGFR (±3 mL/min/1.73 m²), and BMI (±2.5 kg/m²). Results In the whole population (n = 6,158), median [IQR] age was 61 [47; 72] years, with 45.8% of women. Mean measured GFR (mGFR) was 60 [39; 82] mL/min/1.73 m². Compared to non-diabetic subjects (n = 5,124), diabetic patients (n = 1,034) were older, more frequently males, heavier, had lower mGFR (45 vs 64 mL/min/1.73 m²), and higher creatinine (1.44 vs 1.06 mg/dL; p < 0.0001) and cystatin C (1.67 vs 1.20 mg/L) concentrations. The performance of the EKFCcys equation was similar to EKFCcrea, but the EKFCcrea+cys had better P30 than single-biomarker equations. Globally, P30 were substantially lower in diabetic patients than in non-diabetic patients (Table). We could match data for 289 females and 546 males. The results in the matched cohorts were quite similar between diabetics and non-diabetics subjects, and this is true for every equation. Conclusion In conclusion, in a large dataset of patients including diabetics and non-diabetics, we showed that the EKFC equations are accurate in diabetic and non-diabetic patients. Combining the creatinine and cystatin C-based equations presents an added value. If accuracy of all equations seems better in non-diabetic than in diabetic subjects, it is probably more due to differences in age and (still more) in GFR levels than to the diabetic status.

#1320 Differential microRNA expression profile in obesity-induced kidney disease driven by high-fat diet in mice

Abstract Background and Aims Obesity is one of the main causes of chronic kidney disease; however, the precise molecular mechanisms leading to the onset of kidney dysfunction in obesity-induced kidney disease (OIKD) remain unclear. MicroRNAs (miRNAs) have been implicated in the development and progression of obesity, and several candidates have been identified as critical regulators of adipogenesis and lipid metabolism, while their dysregulation contribute to obesity-related metabolic abnormalities. The aim of the present study was to decipher the kidney microRNA (miRNA) expression profile in a mouse model of obesity-induced kidney disease characterized by systemic metabolic disturbances and kidney injury that closely resemble those observed in human disease. Method Male C57BL/6J mice were randomly divided and placed either a standard diet (STD) or a high fat diet (HFD) for 10 weeks. Serum triglycerides and total, HDL and LDL cholesterol were determined by standard clinical methods. In the kidney sections, histopathological assessments were done by using PAS and Oil-Red-O staining's. Expression of renal MCP1, TNFα, α-SMA, Fibronectin, miR-146a, miR-551b and miR-5099 was assessed by real time PCR. In order to elucidate the role of differentially expressed miRNAs, a search for target genes was done using an online computational resource DIANA-miRPath v4.0. Results High fat diet (HFD)-induced obesity led to evident structural alterations in tubular and glomerular regions of the kidney, increased renal expression of adiposity-related proinflammatory and profibrotic genes, as well as an elevated renal expression of genes involved in cellular lipid metabolism. The miRNA sequencing analysis identified a set of 9 miRNAs differentially expressed in the kidney upon HFD feeding, with miR-5099, miR-551b-3p, miR-223-3p, miR-146a-3p and miR-21a-3p showing most significant differential expression between standard diet (STD) and HFD mice. Consistently, Kyoto Encyclopedia of Genes and Genomes (KEGG) and Gene Ontology (GO) enrichment analyses revealed that 3 validated miRNAs (miR-5099, miR-551b-3p and miR-146a-3p) modulated target genes involved in metabolic and adipocytokine pathways, fatty acid and lipid metabolism, inflammatory, senescence and profibrotic pathways. Conclusion Our results propose that differentially expressed miRNAs play pivotal roles in the intricated pathophysiology of obesity-associated kidney disease and could potentially create novel treatment strategies to counteract the deleterious effects of obesity on kidney function.

#1335 Distal radio-cephalic arteriovenous fistula survival: comorbid conditions and long-term surveillance in hemodialysis

Abstract Background and Aims With a low incidence of infection and distal ischemia, the distal radio-cephalic arteriovenous fistula (dRCF) is the reference access for hemodialysis (HD). Smaller venous diameter and obesity have been associated with poor distal arteriovenous fistula (AVF) outcomes in some studies. On the other hand, HD patients often suffer from multiple co-morbidities, resulting in an increased number of complications. The impact of all these factors on vascular access survival has not been entirely characterized. We evaluated long-term follow-up demographic and clinical data from a cohort of patients in relation to primary and secondary dRCF survival. Method The study included prevalent patients who had been receiving hemodialysis for at least 6 months at the same reference hospital. From 2008 to 2023, we retrospectively collected dRCF for HD performed by a single reference surgical team. All dRCF could be confirmed to be clinically useful for dialysis (i.e., functional patency). Socio-demographic data were collected. Our medical team (nephrologist and radiologist) periodically performs a physical examination and duplex ultrasound to identify physical signs of possible complications, understand the underlying cause and plan treatment in advance. The time to first repair is termed primary AVF survival, while secondary survival is the time after first repair. Primary and secondary survival analysis was performed using the Kaplan-Meier method. Results Of 253 prevalent patients receiving HD, 82.2% had an AVF. The mean HD vintage was 61 ± 50 months. HD was started on a planned basis in 61.4% of cases, with AVF being the initial access in 71.7% of cases. We included 145 dRCFs for HD. dRCF was the unique AVF that was placed in 74.5% of the patients. Mean age 69.5 ± 14.5 (years), women 31%, mean BMI 27.3 ± 6.08 kg/m2, non-smokers 46.9%, obesity 37.9%, diabetes mellitus 44.8%, ischemic cardiopathy 20%, peripheric vasculopathy 15.9%. Diabetic nephropathy was the most common cause of chronic kidney disease in our population, accounting for 44.8% of cases. dRCF primary failure was 11.11%, 40% of these patients were over 80 years of age. The dRCF was left-sided in 82.2%. dRCF median survival was 64.5 ± 50.4 months; survival rates at 12, 36 and 60 months were 92%, 67% and 41%, respectively. Primary and secondary dRCF median survival was 33 ± 39 months and 50 ± 45 months, respectively. Primary and secondary survival rates at 12, 36 and 60 months were 60%, 32% and 17% and 84%, 53% and 33%, respectively. With a median survival of 62 ± 44 months, 29.7% of the dRCF did not undergo repair either before or during dialysis. The dRCF requiring percutaneous intervention and/or surgical reanastomosis before dialysis was 16.7%. Factors identified as being associated with lower primary survival were obesity and peripheral vasculopathy (p=0.01 and p=0.001, respectively), as shown in Figs. 1 and 2. The percentage of salvage procedures (percutaneous, surgical or both) in obese was 78,2%; 76,7% involved surgical repair, most of which were lipectomies, superficializations with or without transposition. Although not statistically significant (p=0.056), dRCF secondary survival is decreased in diabetic patients (Fig. 3). No statistical impact was found between age, sex, smoking, or ischemic cardiopathy and either primary or secondary survival. Conclusion Our obese patients on HD are a special population with an increased need for surgical reintervention of dRCF, which impacts primary but not secondary survival. Primary dRCF survival is lower in patients with peripheral vascular disease compared to other comorbidities; however, this vasculopathy is not associated with worse secondary dRCF survival with active follow-up. It is likely that individualized and careful long-term active surveillance was a key aspect in improving the functional patency of dRCF in our patients with multiple comorbidities. Undoubtedly, these issues deserve further prospective investigation.

#2293 Cardiac autonomic neuropathy: an independent risk factor for renal decline in diabetic kidney disease

Abstract Background and Aims Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease (CKD) and end stage kidney disease (ESKD) in the UK and worldwide. Due to its unpredictability and incurable nature, novel risk factors associated with incidence and progression of DKD need to be identified. One such factor is cardiac autonomic neuropathy (CAN). Many studies over last 30 years had demonstrated a significant relationship between CAN and incidence and progression of DKD using estimated glomerular filtration rate (eGFR) and urinary albumin creatinine ratio (UACR) as end points. However, no prospective studies have looked into relationship between CAN diagnosed by gold standard cardiac autonomic reflex tests (CARTs) and DKD with different prognostic risks as per KDIGO classification. The aim of the study is to examine this relationship further. Method Data from 91 participants (type 1 and type 2 DM) with eGFR >30 ml/min/1.73 m2 who underwent assessment for CAN using CARTs as per O'Brien's and Ewing's criteria during baseline visits performed between 2007 and 2010 were collected. Additional participants (n = 113) were also recruited in 2021 as part of iBEAt study which is an EU-funded, multi-centre renal imaging study to identify novel biomarkers for DKD. Data analysis for 204 participants in total was performed for this study. CAN was defined as 2 or more abnormal CARTs out of 5 (Table 1). The level of prognostic risk was calculated based on eGFR (G1-G5) and UACR (A1-A3), following KDIGO risk table from 2012 CKD guidelines. eGFR was calculated by chronic kidney disease epidemiology collaboration (CKD-EPI) equation and UACR was assessed by early morning urine sample. Participants were categorised as follow: low risk, moderate risk and high risk. Due to limited numbers of participants with G3 in eGFR, we have combined ‘high risk’ and ‘very high risk’ into one group. CAN was divided into 2 groups—with and without CAN. Differences in proportions were examined using chi-square test. The association between baseline CAN and risk of renal decline was assessed using multinominal logistic regression adjusted for baseline age, HbA1c, ACEi/ARBs use, retinopathy status, total cholesterol and triglyceride. If significant differences were found, individual groups were compared by Bonferroni post hoc test. All analyses were performed in SPSS (version 29.0) and correlations were considered significant if p < 0.05. Results We analysed data of 204 participants (130 T1DM, 74 T2DM), 44.6% (n = 91) of them were women, mean (SD) age at baseline visit was 51 (15.7) years, eGFR 82.6 (13) ml/min/1.73 m2, UACR 5.2 (21.8) mg/mmol, duration of diabetes at baseline 19.7 (12.3) years and 36.8% had hypertension. Baseline eGFR and UACR were available for 198 and 193 participants respectively. Of these, 42.9% (85/198) had G1, 47.5 (94/198) had G2 and 9.6 (19/198) had G3. For UACR, 80.8% (156/193) had A1, 15.5% (30/193) had A2 and 3.6% (7/193) had A3. 53.4% (103/204) of participants had CAN and 46.6% (101/204) had no CAN. A higher proportion of participants was in low prognostic risk category 77.8% (154/198), followed by 13.1% (26/198) with moderate risk and 9.8% (18/198) with high risk for CKD progression. The risk of DKD progression was significantly associated with presence of CAN in multinominal logistic regression analysis (p = 0.020). The presence of CAN was closely related to low risk (95% CI: 1.44 to 22.04, p = 0.013) and moderately increased risk (95% CI: 1.03 to 24.7, p = 0.04). The participants with moderate and high risk had lower eGFR (p < 0.001) and higher UACR with increased risk (p < 0.001) (Table 2). This finding was independent of baseline age, HbA1C, retinopathy, ACEI/ARB use, type of diabetes, cholesterol and triglyceride levels at baseline as measured by logistic regression. Conclusion To our knowledge, this is one of the first studies to examine the relationship between presence of CAN in three stages of prognostic risk in DKD. We demonstrated that presence of CAN was an independent risk factor for decline in renal function in DKD. Further large prospective studies are required to confirm the findings of this study and examine the underlying mechanisms how CAN leads to greater risk of DKD.

#1978 Proteomic analysis of exosomes derived from mesangial cells treated with galactose-deficient IgA1

Abstract Background and Aims IgA nephropathy (IgAN) is an autoimmune disease characterized by IgA deposits that build up in the kidneys, inflame and damage glomeruli causing hematuria and proteinuria. It is a leading cause of chronic kidney disease, which often results in end-stage kidney disease. There is no disease specific treatment for IgAN. The glomerulus, in which IgA1 lacking galactose residues (gdIgA1) are deposited, consists of mesangial cells, podocytes, and endothelial cells. Crosstalk between the cell types allows the glomerulus to act as a unit and react to its dynamic environment. There is very little evidence on mesangial cell derived exosomes and their cargo to understand the pathological crosstalk signaling in the glomerulus of IgAN. We isolated exosomes from mesangial cells that were treated with patient-derived gdIgA1 and IgA1 complexes. Proteomic analysis was performed to identify the exosome cargo and delineate the signaling pathways leading to maladaptive paracrine crosstalk. From our study, we aim to understand the molecular targets for therapeutic strategies in IgAN. Method Human mesangial cells were treated with/without IgA1, gdIgA1 or IgG for 24 h. Cell culture supernatant was collected for exosome isolations. Exosomes were analyzed by size, morphology and number using TEM and NanoFCM. Exosome protein extracts were processed for LC-Tandem mass spectrometry analysis using filter-aided sample preparation protocol. Proteomic analysis was performed using Qlucore omics explorer and pathway analysis using Ingenuity Pathway Analysis (IPA). Exosome marker expressions such as CD63, CD81 and FLOT1 and proteome validation was performed using Western blotting. Statistical analysis was performed using GraphPad Prism and values <0.05 were considered significant. Results We confirmed the release of exosomes by mesangial cells in response to IgA1/gdIgA1 complexes. Exosomes were fewer in unstimulated cells as compared to IgA1/gdIgA1 treated cells. They showed round morphology with a dense core and uniform size distribution. Exosomes from treated cells showed a mean size of about 75 nm and concentration in the range of 1-2 × 10^10 particles/ml. While untreated cells showed a mean size of about 100 nm and concentration of about 1 × 10^9 particles/ml. We confirmed the protein expression of exosome markers such as CD63, CD81 and FLOT1. For the first time, we demonstrated global proteomics on exosomes from mesangial cells followed by pathway analysis. We have identified 89 unique proteins and pathways in exosomes derived from gdIgA1 treated mesangial cells that could mediate pathological signaling in the glomerulus in comparison to exosomes derived from IgA1 treated mesangial cells. Conclusion Our study provides an understanding of the pathological crosstalk signaling through exosomes and key molecular targets for IgAN.

#1507 Genetics in suspected cases of hereditary kidney diseases

Abstract Background and Aims Hereditary kidney diseases are the fifth cause of chronic kidney disease (CKD). They are responsible for around 10% of adults with kidney replacement therapy. Genetic testing in suspected cases allows us to make a definitive diagnosis, prognosis, therapeutic options and family counselling. Method We present a descriptive study from Hospital Clínic Barcelona (Spain) of all genetic tests performed in suspected cases of hereditary kidney diseases between 2019 and 2023 by using whole exome sequencing. Diseases are classified into these groups: cyst kidney diseases, Alport syndrome spectrum (ASS), complement-related kidney diseases, tubulointerstitial kidney disease (TID), CKD of unknow etiology (CKDUE), podocytopathies, and miscellaneous. All analyses were made with blood samples. Results As of December 31st, genetic test has been made in 198 patients, of which 172 have definitive results (82/172 women). Genetic tests increase over time with 10 (2019), 15 (2020), 36 (2021), 56 (2022) and 81 (2023). The most frequent suspected genetic kidney diseases were cyst-related (n = 57) followed by CKDUE (n = 43), complement-related kidney disease (n = 27), ASS (n = 20), podocytopathies (n = 16) and TID (n = 6). Globally, 104 genetic alterations were detected; 40,7% (70/172) were pathogenic or likely pathogenic (P/LP) variants; and 19,8% (34/172) were variants of uncertain significance (VUS). The highest test performance was observed in the cyst-related group with 70,2% (40/57) followed by ASS with 45% (9/20) and TID with 33,1% (2/6) while the lowest performance groups were CKDUE and complement-related diseases with 25,6% (11/43) and 11,1% (3/27) respectively. The most frequent P/LP variants identified per group were PKD1 (28/40) and PKD2 (12/40) in cyst-related; COL4A4 (5/9) in ASS; CFH, COQ8B and C3 (1/3 each one) in complement-related; UMOD and MUC (1/2 each one) in TID; COL4A4 (2/11) in CKDUE; and TRPC6:1, LMXB1, COL4A3, COL4A5 and COQB8 (1/5 each one) in podocytopathies. The highest genetic heterogeneity was found in CKDUE with 28 genetic variants detected (11 P/LP and 17 VUS). Conclusion Although the comparison between the different groups of diseases is complex, because of the different genetic study indication in each one, as well as their prevalence and the performance of the test, in our cohort the most suspected hereditary kidney diseases in which a genetic test was performed was cyst-related diseases, with the highest P/LP variants found and the highest test performance. However, it is worth noting that more than half of the patients had non-related cystic disease, thus increasing the knowledge and detection of less common genetic kidney diseases. CKDUE is the second group with more P/LP variants and with the highest heterogeneity. It is essential that national health systems provide access to genetic tests to complete the study of CKD of unknow etiology.

#2771 Peritoneal dialysis after kidney graft loss … and now, what?

Abstract Background and Aims The evolution of peritoneal dialysis (PD) as renal replacement therapy (RRT) after graft loss is not well defined. Method Retrospective analysis of the Andalusian Renal Registry of patients who received their first kidney transplant (KT) in Andalusia (Spain) and returned to dialysis between 1978-2023. Patients who lost follow-up and those who underwent preemptive re-KT were excluded of the study. We compared clinical characteristics and evolution between those who started hemodialysis (HD) and peritoneal dialysis (PD) after graft loss. Secondly, we analyzed technique and patient survival in those who started PD post-KT versus patients on PD as their first renal replacement therapy (RRT) We performed multivariate analysis for PD technique and patient survival risk factors using Cox regression. Results During this period, we followed 11868 KT recipients in Andalusia. Of these, 3148 (26.52%) lost the graft: 2768 started HD and 298 PD. 82 patients underwent preemptive re-KT. Patients who returned to DP were younger (p < 0.001) and glomerulonephritis as cause of chronic kidney disease (CKD) was more frequent (p = 0.019). The pre-KT RRT was HD in 96.3% of patients starting HD post-KT and PD in 48.3% of patients who returned to PD after KT (p < 0.001). Survival of patients in the HD group was lower than those who started PD (p = 0.026). In the multivariate analysis, older age when dialysis restarted, male sex and diabetes were risk factors for patient death and not the type of dialysis. When comparing only the post-KT PD group (n = 298) versus patients on PD as their first RRT (n = 5312), patients on the first group were younger (57.1 vs. 41.9; p < 0.001) and time on PD was longer (24.4 vs. 19 months; p < 0.001). The causes of PD drop-out also varied between groups (p < 0.001). During this period, 269 post-KT PD patients left the technique mainly due to re-KT (34.3%) and in the PD group as the first RRT, there were 4919 technique drop-outs, mainly due to transfer to HD (35.3%) and death (30%). The percentage of peritonitis was higher in the post-KT PD group, although without significant differences (post-KT PD 27.9% vs. PD as first RRT 23.25%; p = 0.061). Survival of the DP technique in post-KT PD group was 78.2% at 1 year and 38.5% at 5 years, and 77.7% and 42.1% respectively in the DP group as the first DP RRT (p = 0.059). In the multivariate analysis, patient age and diabetes as a cause of CKD, behaved as risk factors for patient survival. Conclusion Almost half of the patients starting PD after KT had been on PD prior to transplantation. They tend to have more peritonitis although survival of the technique and complications were very similar to those observed in patients on PD as first RRT.

#3011 Pathophysiological link between renal and cardiovascular disease in patients with type 2 diabetes mellitus: preliminary results from a proteomic study

Abstract Background and Aims Diabetic kidney disease (DKD) affects nearly 40% of people with diabetes and is the leading cause of chronic kidney disease (CKD). A high prevalence of cardiovascular disease (CVD) is known in this population. Indeed, DKD and CVD are often related and lead to worse outcomes in type 2 diabetes mellitus (T2D), i.e. cardiac fibrosis and CV events are frequently described in patients with DKD. However, specific associations and accurate prediction biomarkers for DKD and CVD progression in T2D are still lacking as various proteins may play a multi-mechanistic role. Lipocalin-2 (LCN2) is involved in several pathophysiological processes (inflammation, renal disease and cardiometabolic complications in CKD). Its leukocyte-chemoattractant effect has shown to reduce CVD in experimental models of cardiomyopathy when suppressed. Excess LCN2 in CKD is a determinant of disease progression, but also a potent mediator of cardiac injury in CKD. Insulin-like growth factor binding proteins (IGFBPs) also play an important role in cell homeostasis by regulating cell transcription, migration, and apoptosis. IGFBP-3 down-regulation has demonstrated to be a predictor of rapid renal progression in T2DM. On the other hand, IGFBP-6 increases when GFR drops, being involved in the pathophysiological process of CKD as an apoptosis-inducing protein In this context, a proteomic-based approach would optimise the clinical utility of multiple plasma biomarkers. The aim was to identify proteins associated with DKD, cardiac fibrosis (estimated by the PICP biomarker) and the presence of a new CV event. Method A prospective cohort of 91 T2D patients, with a minimum follow-up of 3 years (mean: 4 years) was analysed. We evaluated the association between rates of change in GFR and PICP during follow-up (fold-change: end/initial) and their interaction with the development of a composite of cardiovascular (CV) events: CV death, stroke, ischaemic heart disease, atrial fibrillation, valvular heart disease and CV-related hospitalisation. In addition, ninety-two proteins were quantified in serum samples using a multiplex proximity extension assay with high-throughput protein detection technology (Olink proteomics, Cardiometabolic panel). Associations between variations in these proteins and changes in PICP and eGFR (all expressed as fold change from baseline) were assessed using linear regression analyses adjusted for their respective baseline values. All analyses were adjusted by multiple testing (Benjamini-Hochberg, FDR = 0.05%) using R software. Results Sixty-eight (74.7%) men and 23 (25.3%) women were included in the analysis. The mean age at baseline was 65.8 years, and the mean follow-up was 4 years (minimum 3 years). Sixteen cardiovascular events were recorded. An inverse association was observed between GFR and PICP (p = 0.003). Interaction analysis showed that this correlation occurred only in patients with incident CV events (p for interaction <0.001) (Fig. 1). By proteomic analysis (Fig. 2) several proteins were found to be significantly related to one of the three parameters studied (change in GFR, change in PICP and change with cardiovascular event), of which 3 proteins presented an overlap for all the parameters analysed: Lipocalin 2 (LCN2) and Insulin-like growth factor binding proteins 3 and 6 (IGFBP3 and IGFBP6). Interestingly, LCN2 and IGFBP6 were more highly expressed in patients with CV events whereas IGFBP3 was downregulated in these patients. Conclusion In patients with DKD, worsening enal function is associated with elevated circulating levels of the collagen synthesis biomarker PICP, particularly in those who developed at least one CV event. The link shown with LCN2, IGFBP-6 and IGFBP-3 shed light on possible multi-mechanistic pathways involved in DKD and narrow the scope towards a common pathway involving an interaction between pro-apoptotic and local inflammatory factors.

#2641 MiR-200b induces ZEB1 mediated upregulation of Matriptase and affects expression of podocin

Abstract Background and Aims Diabetic kidney disease (DKD) is the leading cause of chronic kidney disease and a predominant reason for renal failure. Evidence from previous research indicates that abnormal expression of microRNAs (miRs) links closely to the occurrence and progression of DKD. Methods Expression of miRs in urine samples from DKD patients and in cultured renal cells stressed with transforming growth factor beta 1 (TGF-β1) was evaluated by TaqMan assay. The emerging miR of interest and its downstream targets were analyzed in human renal sections, in cultured human podocytes and in zebrafish. Results Cell free urine screening showed increased abundance of miR-200b in samples from patients with DKD when compared to healthy controls. In situ hybridization confirmed expression of miR-200b in kidney specimens from DKD patients, but was not detected in healthy renal parenchyma. Transcriptome profiling of cultured human podocytes overexpressing miR-200b identified this miR as a regulator of the ZEB1 mediated matriptase (ST14)/ podocin pathway and found TGF- β1 stress to be upstream activators of miR-200b expression in these cells. Immunofluorescence analysis of kidney sections from DKD patients showed increased expression of ST14 and decreased expression of podocin when compared to healthy controls. Furthermore, injection of a miR-200b mimic in zebrafish larvae caused an upregulation of ST14 and was accompanied by phenotypic changes such as edema, proteinuria and podocyte effacement. Conclusion Our results show that miR-200b is expressed in glomeruli and found at elevated levels in urine of DKD patients. Overexpression of miR-200b in cultured podocytes and in zebrafish induces upregulation of matriptase, a serine protease previously shown to cleave podocin. The observed increase in matriptase and decrease in podocin levels in glomeruli from DKD patients, together with the effect of a miR-200b mimic on proteinuria and ultrastructure of the pronephros in zebrafish positions miR-200b as a key regulator that modulates matriptase overactivation in DKD and warrants further studies.

#803 Identification and validation of immune and cuproptosis-related genes for diabetic nephropathy by WGCNA and machine learning

Abstract Background and Aims As the leading cause of chronic kidney disease, diabetic kidney disease (DKD) is an enormous burden for all healthcare systems around the world. However, its early diagnosis has no effective methods. Method First, gene expression data in GEO database were extracted, and the differential genes of diabetic tubulopathy were obtained. Immune-related gene sets were generated by WGCNA and immune cell infiltration analyses. Then, differentially expressed immune-related cuproptosis genes (DEICGs) were derived by the intersection of differential genes and genes related to cuproptosis and immune. To investigate the functions of DEICGs, volcano plots and GO term enrichment analysis was performed. Machine learning and protein-protein interaction (PPI) network analysis helped to finally screen out hub genes. The diagnostic efficacy of them was evaluated by GSEA analysis, receiver operating characteristic (ROC) curve, single-cell RNA sequencing and the Nephroseq website. The expression of hub genes at the animal level by STZ -induced and db/db DKD mouse models was further verified. Results Finally, three hub genes, including FSTL1, CX3CR1 and AGR2 that were up-regulated in both the test set GSE30122 and the validation set GSE30529, were screened. The areas under the curve (AUCs) of ROC curves of hub genes were 0.911, 0.935 and 0.922, respectively, and 0.946 when taking as a whole. Correlation analysis showed that the expression level of three hub genes demonstrated their negative relationship with GFR, while those of FSTL1 displayed a positive correlation with the level of serum creatinine. GSEA was enriched in inflammatory and immune-related pathways. Single-nucleus RNA sequencing indicated the main distribution of FSTL1 in podocyte and mesangial cells, the high expression of CX3CR1 in leukocytes and the main localization of AGR2 in the loop of Henle. In mouse models, all three hub genes were increased in both STZ-induced and db/db DKD models. Conclusion Machine learning was combined with WGCNA, immune cell infiltration and PPI analyses to identify three hub genes associated with cuproptosis, immunity and diabetic nephropathy, which all have great potential as diagnostic markers for DKD and even predict disease progression.

Glomerular crescents are associated with the risk of type 2 diabetic kidney disease progression: a retrospective cohort study

BackgroundDiabetic kidney disease (DKD) stands as the predominant cause of chronic kidney disease and end-stage kidney disease. Its diverse range of manifestations complicates the treatment approach for patients. Although kidney biopsy is considered the gold standard for diagnosis, it lacks precision in predicting the progression of kidney dysfunction. Herein, we addressed whether the presence of glomerular crescents is linked to the outcomes in patients with biopsy-confirmed type 2 DKD.MethodsWe performed a retrospective evaluation, involving 327 patients diagnosed with biopsy-confirmed DKD in the context of type 2 diabetes, excluding cases with other glomerular diseases, from nine tertiary hospitals. Hazard ratios (HRs) were calculated using a Cox regression model to assess the risk of kidney disease progression, defined as either ≥ 50% decrease in estimated glomerular filtration rates or the development of end-stage kidney disease, based on the presence of glomerular crescents.ResultsOut of the 327 patients selected, ten patients had glomerular crescents observed in their biopsied tissues. Over the follow-up period (median of 19 months, with a maximum of 18 years), the crescent group exhibited a higher risk of kidney disease progression than the no crescent group, with an adjusted HR of 2.82 (1.32–6.06) (P = 0.008). The presence of heavy proteinuria was associated with an increased risk of developing glomerular crescents.ConclusionThe presence of glomerular crescents is indeed linked to the progression of type 2 DKD. Therefore, it is important to determine whether there is an additional immune-mediated glomerulonephritis requiring immunomodulation, and it may be prudent to monitor the histology and repeat a biopsy.

Diabetes and Renal Complications: An Overview on Pathophysiology, Biomarkers and Therapeutic Interventions.

Diabetic kidney disease (DKD) is a major microvascular complication of both type 1 and type 2 diabetes. DKD is characterised by injury to both glomerular and tubular compartments, leading to kidney dysfunction over time. It is one of the most common causes of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Persistent high blood glucose levels can damage the small blood vessels in the kidneys, impairing their ability to filter waste and fluids from the blood effectively. Other factors like high blood pressure (hypertension), genetics, and lifestyle habits can also contribute to the development and progression of DKD. The key features of renal complications of diabetes include morphological and functional alterations to renal glomeruli and tubules leading to mesangial expansion, glomerulosclerosis, homogenous thickening of the glomerular basement membrane (GBM), albuminuria, tubulointerstitial fibrosis and progressive decline in renal function. In advanced stages, DKD may require treatments such as dialysis or kidney transplant to sustain life. Therefore, early detection and proactive management of diabetes and its complications are crucial in preventing DKD and preserving kidney function.

Prevalence of dysmagnesemia among CKD patients in North India

Prevalence of dysmagnesemia among CKD patients in North India

Protocol for a systematic review of the application of the kidney failure risk equation and Oxford classification in estimating prognosis in IgA nephropathy

BackgroundIgA nephropathy (IgAN) is a common cause of chronic kidney disease (CKD) and end-stage renal disease (ESRD). Outcomes are highly variable and predicting risk of disease progression at an individual level is challenging. Accurate risk stratification is important to identify individuals most likely to benefit from treatment. The Kidney Failure Risk Equation (KFRE) has been extensively validated in CKD populations and predicts the risk of ESRD at 2 and 5 years using non-invasive tests; however, its predictive performance in IgAN is unknown. The Oxford classification (OC) describes pathological features demonstrated on renal biopsy that are associated with adverse clinical outcomes that may also inform prognosis. The objective of this systematic review is to compare the KFRE with the OC in determining prognosis in IgAN.MethodsA systematic review will be conducted and reported in line with PRISMA guidelines (PRISMA-P checklist attached as Additional file 1). Inclusion criteria will be cohort studies that apply the KFRE or OC to determine the risk of CKD progression or ESRD in individuals with IgAN. Multiple databases will be searched in duplicate to identify relevant studies, which will be screened first by title, then by abstract and then by full-text analysis. Results will be collated for comparison. Risk of bias and confidence assessments will be conducted independently by two reviewers, with a third reviewer available if required.DiscussionIdentifying individuals at the highest risk of progression to ESRD is challenging in IgAN, due to the heterogeneity of clinical outcomes. Risk prediction tools have been developed to guide clinicians; however, it is imperative that these aids are accurate and reproducible. The OC is based on observations made by specialist renal pathologists and may be open to observer bias, therefore the utility of prediction models incorporating this classification may be diminished, particularly as in the future novel biomarkers may be incorporated into clinical practice.Systematic review registrationPROSPERO CRD42022364569

Benefits of using SLGT2 Inhibitors for Patients with CDK and DM2 to Reduce Mortality Risks

Type 2 diabetes mellitus (T2DM) is the most common cause of chronic kidney disease (CKD). CKD is characterized by progressive liver tissue damage and is an important risk factor for mortality due to renal and cardiovascular outcomes. Thus, randomized clinical trials have investigated the use of sodium-glucose cotransporter 2 (SLGT2) inhibitors as a promising therapy for patients with CKD and T2DM. This study aimed to analyze the benefits of using SGLT2 inhibitors in patients with CKD and T2DM to reduce mortality risks. To this end, a qualitative, descriptive methodological approach was adopted using a literature review in the PubMed, Embase, and VHL databases. The inclusion criteria were clinical trial articles, randomized or non-randomized, cohort studies, case-control studies, and open access, published in Portuguese and English, between 2018 and 2023 with topics associated with SGLT2 inhibitors, CDK, and T2DM patients. In this context, it was observed that the risk of death from CKD in patients treated with Canaglifozin was 30% lower than in those treated with a placebo and that Dapaglifozin prolonged survival. In this context, when assessing the progression of kidney disease or death from cardiovascular causes in patients taking Empagliflozin, only 13.1% achieved the outcome compared to 16.9% on placebo, so the drug safely reduces the risk of mortality. Consequently, SGLT2 inhibitors have shown excellent results in the treatment of CDK and T2DM, with a reduction in the risk of mortality, positive effects on reducing renal and cardiovascular outcomes, as well as prolonging survival.

Non-diabetic nephropathy in diabetic patients: incidence, HbA1c variability and other predictive factors, and implications.

Diabetes mellitus (DM) is the leading cause of chronic kidney disease (CKD) in the population. In patients with diabetes mellitus, the incidence of non-diabetic nephropathy (NDNP) has been estimated to range from 3% to 69.5%. Personal judgment is frequently employed while deciding whether or not to do a kidney biopsy(KB) on diabetic patients. NDNP alters the prognosis and course of treatment for people with DM. In our study, we examined the incidence of NDNP concurrent with the progression of diabetes mellitus, as well as the laboratory and clinical indicators that could be utilized to forecast it. A retrospective analysis of 76 diabetic patients who underwent KB was conducted. Based on the pathological diagnoses of these patients, they were categorized as DNP (diabetic nephropathy) or NDNP. The definition of HbA1c variability was determined by calculating the mean HbA1c and the average value of the HbA1c measurements, as well as the standard deviation (SD) for each participant. NDNP was detected in 50% of 76 patients. Among patients with NDNP, 36.8% had focal segmental glomerulosclerosis (FSGS), 23.6% had membranous glomerulonephritis, and 7.8% had IgA nephritis. The NDNP group exhibited significantly higher rates of female gender, absence of diabetic retinopathy, shorter time to diagnosis of diabetes mellitus, chronic kidney disease, and proteinuria, less intensive medication for diabetes mellitus, presence of hematuria and leukociduria, immunological serological marker positivity, and non-HbA1C variability. Risk factors for predicting non-diabetic nephropathy, as determined by multivariate analysis, included female gender, the absence of diabetic retinopathy, non-HbA1c variability and a positive immunological serological test. In this study, a significant number of diabetic patients with chronic kidney disease were diagnosed with NDNP. Identifying these patients allows for treatment of the specific underlying disease. Factors such as the absence of DR, non-HbA1c variability, female gender, and immunological serological test positivity can predict NDNP and guide the clinician's decision on kidney biopsy. Further prospective studies are warranted to validate the efficacy of potential predictive factors like HbA1c variability.

Roles of AhR/CYP1s signaling pathway mediated ROS production in uremic cardiomyopathy

PurposeUremic cardiomyopathy (UCM) is the leading cause of chronic kidney disease (CKD) related mortality. Uremic toxins including indoxyl sulfate (IS) play important role during the progression of UCM. This study was to explore the underlying mechanism of IS related myocardial injury. MethodsUCM rat model was established through five-sixths nephrectomy to evaluate its effects on blood pressure, cardiac impairment, and histological changes using echocardiography and histological analysis. Additionally, IS was administered to neonatal rat cardiomyocytes (NRCMs) and the human cardiomyocyte cell line AC16. DHE staining and peroxide-sensitive dye 2′,7′-dichlorofluorescein diacetate (H2DCFDA) was conducted to assess the reactive oxygen species (ROS) production. Cardiomyocyte hypertrophy was estimated using wheat germ agglutinin (WGA) staining and immunofluorescence. Aryl hydrocarbon receptor (AhR) translocation was observed by immunofluorescence. The activation of AhR was evaluated by immunoblotting of cytochrome P450 1 s (CYP1s) and quantitative real-time PCR (RT-PCR) analysis of AHRR and PTGS2. Additionally, the pro-oxidative and pro-hypertrophic effects were evaluated using the AhR inhibitor CH-223191, the CYP1s inhibitor Alizarin and the ROS scavenger N-Acetylcysteine (NAC). ResultsUCM rat model was successfully established, and cardiac hypertrophy, accompanied by increased blood pressure, and myocardial fibrosis. Further research confirmed the activation of the AhR pathway in UCM rats including AhR translocation and downstream protein CYP1s expression, accompanied with increasing ROS production detected by DHE staining. In vitro experiment demonstrated a translocation of AhR triggered by IS, leading to significant increase of downstream gene expression. Subsequently study indicated a close relationship between the production of ROS and the activation of AhR/CYP1s, which was effectively blocked by applying AhR inhibitor, CYP1s inhibitor and siRNA against AhR. Moreover, the inhibition of AhR/CYP1s/ROS pathway collectively blocked the pro-hypertrophic effect of IS-mediated cardiomyopathy. ConclusionThis study provides evidence that the AhR/CYP1s pathway is activated in UCM rats, and this activation is correlated with the uremic toxin IS. In vitro studies indicate that IS can stimulate the AhR translocation in cardiomyocyte, triggering to the production of intracellular ROS via CYP1s. This process leads to prolonged oxidative stress stimulation and thus contributes to the progression of uremic toxin-mediated cardiomyopathy.