Omentin reduces venous neointimal hyperplasia in arteriovenous fistula through hypoxia-inducible factor-1 alpha inhibition.

Arteriovenous fistula (AVF) failure often involves venous neointimal hyperplasia (VNH) driven by elevated hypoxia-inducible factor-1 alpha (HIF-1α) in the venous wall. Omentin, known for its anti-inflammatory and anti-hyperplasia properties, has an uncertain role in early AVF failure. This study investigates omentin's impact on VNH using a chronic renal failure (CRF) rabbit model. The CRF rabbit model of AVF received omentin-expressing adenoviral vector or control ß-gal vector to assess omentin's effects on VNH. Human vascular smooth muscle cells (HVSMCs), stimulated with tumor necrosis factor-α (TNF-α), were exposed to recombinant human omentin (Rh-OMT) to study its influence on cell proliferation and migration. The AMP-activated protein kinase (AMPK) inhibitor compound C and the mammalian target of rapamycin (mTOR) activator MHY1485 were employed to explore omentin's mechanisms in VNH reduction through HIF-1α inhibition. Omentin treatment reduced VNH in CRF rabbits, concomitant with HIF-1α down-regulation and the suppression of downstream factors, including vascular endothelial growth factor and matrix metalloproteinases. Rh-OMT inhibited TNF-α-induced HVSMC proliferation and migration by modulating both cell cycle and cell adhesion proteins. Additionally, omentin reduced HIF-1α expression through the AMPK/mTOR pathway activation. Notably, the blockade of AMPK/mTOR signaling reversed omentin-mediated inhibition of VNH, cell proliferation, and migration, both in vivo and in vitro. In conclusion, omentin mitigates VNH post-AVF creation by restraining HIF-1α via AMPK/mTOR signaling. Strategies boosting circulating omentin levels may offer promise in averting AVF failure.

A TMEM16J variant leads to dysregulated cytosolic calcium which may lead to renal disease.

SIGIRR (single immunoglobulin IL-1 related receptor), PKP3 (plakophilin 3), and TMEM16J (anoctamin 9), a putative calcium-activated ion channel and phospholipid scramblase, control the immune response and the extent of inflammation. Variants of SIGIRR/PKP3/TMEM16J lead to severe inflammatory diseases such as pneumonia, enterocolitis, and kidney graft rejection. Meta-analysis of genome-wide association studies identified TMEM16J-T604A as a promotor for chronic kidney disease (CKD), but the disease mechanism and function of TMEM16J remain unknown. Here, we demonstrate TMEM16J as a calcium-activated calcium-permeable channel, which is expressed in the endoplasmic reticulum (ER). TMEM16J controls the intracellular distribution of calcium, and inhibits intracellular receptor-mediated Ca2+ signals and Ca2+ -dependent activation of ion channels, but augments transcription and release of pro-inflammatory cytokines. Renal epithelial cells expressing the variant TMEM16J-T604A show enhanced calcium signals when compared to cells expressing wt-TMEM16J, and demonstrate spontaneous transcription and release of cytokines. This study identifies TMEM16J as an important regulator of intracellular Ca2+ signals, ion channel activity, and cytokine release. TMEM16J may therefore affect immune response in renal tissue and immune cells.

Prevalence, patient burden and physicians' perception of pruritus in haemodialysis patients.

BACKGROUND: Chronic kidney disease-associated pruritus (CKD-aP) is an underrated symptom in patients with impaired kidney function. The present study assessed the prevalence, impact on quality of life (QoL) and risk factors for CKD-aP in a contemporary national cohort of patients on haemodialysis. In addition, we evaluated attending physicians' awareness and approach to therapy. METHODS: Validated patient's and physician's questionnaires on pruritus severity and QoL were used in combination with information obtained by the Austrian Dialysis and Transplant Registry. RESULTS: The prevalence of mild, moderate and severe pruritus in 962 observed patients was 34.4%, 11.4% and 4.3%. Physicians' estimated prevalence values were 25.0 (95% CI 16.8-33.2), 14.4 (11.3-17.6) and 6.3% (4.9-8.3), respectively. The estimated national prevalence estimate extrapolated from the observed patients was 45.0% (95% CI 39.5-51.2) for any, 13.9% (95% CI 10.6-17.2) for moderate and 4.2% (95% CI 2.1-6.2) for severe CKD-aP. CKD-aP severity was significantly associated with impaired QoL. Risk factors for moderate-severe pruritus were higher C-reactive protein [odds ratio (OR) 1.61 (95% CI 1.07-2.43)] and parathyroid hormone (PTH) values [OR 1.50 (95% CI 1.00-2.27)]. Therapy for CKD-aP included changes in the dialysis regimen, topical treatments, antihistamines, gabapentin and pregabalin and phototherapy in a majority of centres. CONCLUSIONS: While the overall prevalence of CKD-aP in our study is similar to that in previously published literature, the prevalence of moderate-severe pruritus is lower. CKD-aP was associated with reduced QoL and elevated markers of inflammation and PTH. The high awareness of CKD-aP in Austrian nephrologists may explain the lower prevalence of more severe pruritus.

The long-term effects of dapagliflozin in chronic kidney disease: a time-to-event analysis.

BACKGROUND AND HYPOTHESIS: Chronic kidney disease (CKD) presents a significant clinical and economic burden to healthcare systems worldwide, which increases considerably with progression towards kidney failure. The DAPA-CKD trial demonstrated that patients with or without type 2 diabetes (T2D) who were treated with dapagliflozin experienced slower progression of CKD versus placebo. Understanding the effect of long-term treatment with dapagliflozin on the timing of kidney failure beyond trial follow-up can assist informed decision-making by healthcare providers and patients. The study objective was therefore to extrapolate the outcome-based clinical benefits of treatment with dapagliflozin in patients with CKD via a time-to-event analysis using trial data. METHODS: Patient-level data from the DAPA-CKD trial were used to parameterise a closed cohort-level partitioned survival model that predicted time-to-event for key trial endpoints (kidney failure, all-cause mortality, sustained decline in kidney function, and hospitalisation for heart failure). Data were pooled with a subpopulation of the DECLARE-TIMI 58 trial to create a combined CKD population spanning a range of CKD stages; a parallel survival analysis was conducted in this population. RESULTS: In the DAPA-CKD and pooled CKD populations, treatment with dapagliflozin delayed time to first event for kidney failure, all-cause mortality, sustained decline in kidney function, and hospitalisation for heart failure. Attenuation of CKD progression was predicted to slow the time to kidney failure by 6.6 years (dapagliflozin: 25.2, 95%CI: 19.0-31.5; standard therapy: 18.5, 95%CI: 14.7-23.4) in the DAPA-CKD population. A similar result was observed in the pooled CKD population with an estimated delay of 6.3 years (dapagliflozin: 36.0, 95%CI: 31.9-38.3; standard therapy: 29.6, 95%CI: 25.5-34.7). CONCLUSION: Treatment with dapagliflozin over a lifetime time horizon may considerably delay the mean time to adverse clinical outcomes for patients who would go on to experience them, including those at modest risk of progression.

A Rare Cause of Hypotension in Routine Hemodialysis: Secondary Adrenal Insufficiency.

Hypotension is a common complication during hemodialysis that develops due to high ultrafiltration rate and sometimes requires intravenous fluid replacement. Intradialytic hypotension may reduce the effectiveness of dialysis and contributes to hemodialysis-related morbidity and mortality. Adrenal insufficiency is one of the causes of hypotension in the community. Our case was diagnosed with end-stage renal failure and was undergoing routine hemodialysis with a central venous catheter 3 days a week. Upon the patient's hypotension attacks during the dialysis sessions and hypoglycemia attacks in the follow-ups, the morning cortisol was 6.2 µg/dL. Adrenocorticotropic hormone was 39 pg/mL, and testosterone was 0.0442 ng/mL. Adrenocorticotropic hormone stimulation test was performed on the patient with 250 mcg tetracosactide. The patient did not show adequate cortisol response, was detected to have partial empty sella on pituitary magnetic resonance imaging, and was diagnosed with secondary adrenal insufficiency, and then the hemodialysis hypotension improved with prednisolone treatment. We present a case of adrenal insufficiency, which is a rare cause of hypotension in patients on routine hemodialysis.

Improvement in Echocardiographic Indexes of Systolic Heart Failure Post-Kidney Transplantation: A Retrospective Analysis.

INTRODUCTION: End-stage renal disease is a major risk factor for cardiovascular morbidity and mortality, which can be partially eliminated by kidney transplantation. Systolic heart failure might be considered contraindication for kidney transplant, although some patients demonstrate myocardial recovery post-transplant. We aimed to identify and characterize the phenomenon of reverse myocardial remodeling in kidney transplanted patients. METHODS: The study is a retrospective cohort of patients undergoing kidney transplants between 2016 and 2019 (n = 604) at Rabin Medical Center. Patients were assessed according to availability of two echocardiographic examinations: pre- and post-kidney transplant. The change in estimated ejection fraction (EF) and possible predictors of myocardial recovery were examined. RESULTS: Data of 293 patients was available for the final analysis. Eighty-one (28%) patients had a LVEF improvement equal to or above 5%, whereas 36 (12%) patients had a LVEF improvement of 10% or more post-transplantation. Twenty-five patients (8.5%) had moderate or severe systolic heart failure with LVEF reduced to 40% or less at baseline. 13 of them (52%) had a LVEF improvement of ≥5%, and 10 patients (40%) had an improvement of ≥10% in their EF. Cox regression analyses identified female gender as the only independent variable associated with LVEF improvement of at least 10%. CONCLUSION: Renal transplantation might lead to improved LV systolic function in some patients.

Changes in estimated glomerular filtration rate over the first year following repeat heart transplant in children and young adults.

BACKGROUND: Renal function is reduced in patients undergoing heart transplant due to hemodynamic compromise, cardiorenal syndrome, and nephrotoxin exposure. No current studies evaluate renal function in retransplants. METHODS: We reviewed all heart transplants at our center from 1995 to 2021 and matched first-time heart transplants with retransplants, based on age at transplant, sex, and race. Estimated glomerular filtration rate (eGFR) was derived from CKiD-U25 calculator using creatinine and measured prior to transplant, 1-week post-transplant, 1-3, 6, and 12 months post-transplant, and recent follow-up. Changes in eGFR were measured within and between patients using a piecewise linear mixed effect model with matching. Exploratory univariate analysis was performed to evaluate pre-transplant risk factors for decreased eGFR. RESULTS: The unmatched cohort included 393 heart transplant recipients, with 47 being retransplants. Thirty-eight patients in both groups with at least 1 year of follow-up underwent matching. Both retransplants and first-time transplants had an initial decline in eGFR. eGFR rebounded to baseline or above baseline at 1-3 months post-transplant, but eGFR in retransplants remained significantly lower. At 1-year post-transplant, the average eGFR was 67.8 ± 4.3 mL/min/1.73 m2 versus 104.7 ± 4.3 mL/min/1.73 m2 (p < .001) in the retransplants and first-time transplants group, respectively. CONCLUSION: This study provides data on anticipated renal trajectory following retransplantation.

Cardiovascular Risk in Pediatric Renal Transplant Recipients.

BACKGROUND: The survival of pediatric chronic kidney disease (CKD) patients has improved in recent decades due to advances in dialysis and transplantation. However, cardiovascular disease (CVD) emerges as the main cause of mortality in patients with CKD. OBJECTIVES: To estimate cardiovascular risk in children with CKD at least 1 year after kidney transplantation. In addition, the possible association of cardiovascular risk with classic biochemical markers and potential new markers of this outcome was investigated. METHODS: An observational ambidirectional (retrospective capture of risk factors and prospective study of outcomes) research including 75 patients who underwent renal transplant between 2003 and 2013 with postoperative follow-up of at least 1 year was conducted. The outcome variables adopted were the LV mass Z-score and the presence of coronary calcification on computed tomography using calcium Agatston score. RESULT: Only one patient had an elevated calcium score, and three children (4%) had an LV mass Z-score ≥ 2.0. After multivariable analysis, only gender, serum triglyceride, and serum renalase concentration remained significantly associated with LV mass. CONCLUSION: The low incidence of cardiovascular changes in the population studied confirms the benefit of transplantation for the cardiovascular health of children. Nevertheless, long-term follow-up of these patients is recommended, given the limited duration of kidney function provided by transplantation and the high likelihood of further dialysis and kidney transplants being required in these children.

Establishing an autogenous vascular access program in a Guatemalan comprehensive pediatric nephrology center.

BACKGROUND: The Guatemalan Foundation for Children with Kidney Diseases collaborated with Bridge of Life, a not-for-profit charitable organization, to establish a vascular access program. We reviewed our experience with graded surgical responsibility and structured didactic training, creating arteriovenous fistulas (AVF) for Guatemalan children. METHODS: Pediatric vascular access missions were completed from 2015 to 2023 and analyzed retrospectively. Follow-up was completed by the Guatemalan pediatric surgeons, nephrologists, and nursing staff. AVF patency and patient survival were evaluated by Kaplan-Meier life-table analysis with univariate and multivariable association between patient demographic variables by Cox proportional hazards models. RESULTS: Among a total of 153 vascular access operations, there were 139 new patient procedures, forming the study group for this review. The mean age was 13.6 years, 42.6% were female, and the mean BMI was 17.3. Radial or ulnar artery-based direct AVFs were established in 100 patients (71.9%) and ten of the 25 transposition procedures. Brachial artery inflow was required in 29 direct AVFs (20.9%). Two patients underwent femoral vein transpositions. Access-related distal ischemia was not encountered. Seven of the AVF patients later required access banding for arm edema; all had previous dialysis catheters (mean = 9, range 4-12). Primary and cumulative patency rates were 84% and 86% at 12 months and 64% and 81% at 24 months, respectively. The median follow-up was 12 months. Overall patient survival was 84% and 67% at 12 and 24 months, respectively. There were no deaths related to AVF access. CONCLUSIONS: Safe and functional AVFs were established in a teaching environment within a Guatemalan comprehensive pediatric nephrology center.

SAGES peritoneal dialysis access guideline update 2023.

BACKGROUND: Minimally invasive surgery has been used for both de novo insertion and salvage of peritoneal dialysis (PD) catheters. Advanced laparoscopic, basic laparoscopic, open, and image-guided techniques have evolved as the most popular techniques. The aim of this guideline was to develop evidence-based guidelines that support surgeons, patients, and other physicians in decisions on minimally invasive peritoneal dialysis access and the salvage of malfunctioning catheters in both adults and children. METHODS: A guidelines committee panel of the Society of American Gastrointestinal and Endoscopic Surgeons reviewed the literature since the prior guideline was published in 2014 and developed seven key questions in adults and four in children. After a systematic review of the literature, by the panel, evidence-based recommendations were formulated using the Grading of Recommendations Assessment, Development and Evaluation approach. Recommendations for future research were also proposed. RESULTS: After systematic review, data extraction, and evidence to decision meetings, the panel agreed on twelve recommendations for the peri-operative performance of laparoscopic peritoneal dialysis access surgery and management of catheter dysfunction. CONCLUSIONS: In the adult population, conditional recommendations were made in favor of: staged hernia repair followed by PD catheter insertion over simultaneous and traditional start over urgent start of PD when medically possible. Furthermore, the panel suggested advanced laparoscopic insertion techniques rather than basic laparoscopic techniques or open insertion. Conditional recommendations were made for either advanced laparoscopic or image-guided percutaneous insertion and for either nonoperative or operative salvage. A recommendation could not be made regarding concomitant clean-contaminated surgery in adults. In the pediatric population, conditional recommendations were made for either traditional or urgent start of PD, concomitant clean or clean-contaminated surgery and PD catheter placement rather than staged, and advanced laparoscopic placement rather than basic or open insertion.