Evaluation of a proteomic signature coupled with the kidney failure risk equation in predicting end stage kidney disease in a chronic kidney disease cohort.

BACKGROUND: The early identification of patients at high-risk for end-stage renal disease (ESRD) is essential for providing optimal care and implementing targeted prevention strategies. While the Kidney Failure Risk Equation (KFRE) offers a more accurate prediction of ESRD risk compared to static eGFR-based thresholds, it does not provide insights into the patient-specific biological mechanisms that drive ESRD. This study focused on evaluating the effectiveness of KFRE in a UK-based advanced chronic kidney disease (CKD) cohort and investigating whether the integration of a proteomic signature could enhance 5-year ESRD prediction. METHODS: Using the Salford Kidney Study biobank, a UK-based prospective cohort of over 3000 non-dialysis CKD patients, 433 patients met our inclusion criteria: a minimum of four eGFR measurements over a two-year period and a linear eGFR trajectory. Plasma samples were obtained and analysed for novel proteomic signals using SWATH-Mass-Spectrometry. The 4-variable UK-calibrated KFRE was calculated for each patient based on their baseline clinical characteristics. Boruta machine learning algorithm was used for the selection of proteins most contributing to differentiation between patient groups. Logistic regression was employed for estimation of ESRD prediction by (1) proteomic features; (2) KFRE; and (3) proteomic features alongside KFRE. RESULTS: SWATH maps with 943 quantified proteins were generated and investigated in tandem with available clinical data to identify potential progression biomarkers. We identified a set of proteins (SPTA1, MYL6 and C6) that, when used alongside the 4-variable UK-KFRE, improved the prediction of 5-year risk of ESRD (AUC = 0.75 vs AUC = 0.70). Functional enrichment analysis revealed Rho GTPases and regulation of the actin cytoskeleton pathways to be statistically significant, inferring their role in kidney function and the pathogenesis of renal disease. CONCLUSIONS: Proteins SPTA1, MYL6 and C6, when used alongside the 4-variable UK-KFRE achieve an improved performance when predicting a 5-year risk of ESRD. Specific pathways implicated in the pathogenesis of podocyte dysfunction were also identified, which could serve as potential therapeutic targets. The findings of our study carry implications for comprehending the involvement of the Rho family GTPases in the pathophysiology of kidney disease, advancing our understanding of the proteomic factors influencing susceptibility to renal damage.

Acute kidney injury in patients undergoing endovascular or open repair of juxtarenal or pararenal aortic aneurysms.

BACKGROUND: The aim of this cohort study was to report the proportion of patients who develop periprocedural acute kidney injury (AKI) after endovascular repair (ER) and open surgery (OS) in patients with juxta/pararenal abdominal aortic aneurysm and to assess potential risk factors for AKI. The study also aimed to report the short- and long-term outcomes of patients with and without AKI. METHODS: This was a multicenter cohort study of five European academic high-volume centers (>50 OS or 50 ER infrarenal AAA repairs, plus >15 complex AAA repairs per year). All consecutively treated patients were extracted from a prospective vascular surgical registry and the data were scrutinized retrospectively. The primary end point for this study was the development of AKI. AKI was diagnosed when there is a two-fold increase of serum creatinine or decrease of glomerular filtration rate of >50% within 1 week of AAA repair. Secondary end points included long-term mortality and end-stage renal disease (ESRD). RESULTS: AKI occurred in 16.6% of patients in the ER group vs 30.3% in the OS group (P < .001). The 30-day mortality rate was higher among patients with AKI in both ER (15.4% vs 3.1%; P = .006) and OS (13.2% vs 5.3%; P = .001) groups. Age, chronic kidney disease, presence of significant thrombus burden in the pararenal region, >1000 mL blood loss in ER group were associated with development of AKI. Age, diabetes mellitus, chronic kidney disease, presence of significant thrombus burden in the pararenal region, and a proximal clamping time of >30 minutes in the OS group were associated with the development of AKI, whereas renal perfusion during clamping was the protective factor against AKI development. After a median follow-up of 91 months, AKI was associated with higher mortality rates in both the ER group (58.9% vs 29.7%; P < .001) and the OS group (61.5% vs 27.3%; P < .001). After the same follow-up period, AKI was associated with a higher incidence of ESRD in both the ER group (12.8% vs 3.6%; P = .009) and the OS group (9.9% vs 2.9%; P < .001). CONCLUSIONS: The current study identified important pre and postoperative factors associated with AKI after juxta/pararenal abdominal aortic aneurysm repair. Patients with postoperative AKI had significantly higher short- and long term mortality and higher incidence of ESRD than patients without AKI.

Effect of Cold Versus Hot Snare Polypectomy on Colon Postpolypectomy Bleeding in Patients with End-Stage Renal Disease: A Retrospective Cohort Study.

BACKGROUND: Patients with end-stage renal disease (ESRD) who undergo polypectomy may experience postpolypectomy bleeding. To reduce the risk of delayed postpolypectomy bleeding among the general population, cold snare polypectomy (CSP) is recommended for removing colon polyps smaller than 1 cm. Nevertheless, only few studies have examined the effect of CSP on patients with ESRD. METHODS: We retrospectively analyzed the data of patients with ESRD who underwent colonoscopic polypectomy for polyps larger than 5 mm at a Taiwanese university hospital from January 2014 to January 2023. The main outcome was delayed postpolypectomy bleeding within 30 days. Multivariate analysis was conducted to adjust for major confounders. RESULTS: A total of 557 patients with ESRD underwent colonoscopic polypectomy during the study period: 201 underwent CSP and 356 underwent hot snare polypectomy (HSP). Delayed postpolypectomy bleeding occurred in 27 patients (4.8%). The rate of delayed postpolypectomy bleeding was lower in patients with ESRD who underwent CSP than in those who underwent HSP (1.9% vs. 6.4%, P = 0.022). The percentage of patients who did not experience postpolypectomy bleeding within 30 days after CSP remained lower than that observed after HSP (P = 0.019, log-rank test). Multivariate analysis demonstrated immediate postpolypectomy bleeding and HSP to be independent risk factors for delayed postpolypectomy bleeding. A nomogram prognostic model was used to predict the potential of delayed postpolypectomy bleeding within 30 days in patients with ESRD. CONCLUSIONS: Compared with HSP, CSP is more effective in mitigating the risk of delayed postpolypectomy bleeding in patients with ESRD.

End-stage renal disease in a critical patient with superior vena cava syndrome with central vein catheters inserted via the superficial femoral vein: A case study.

Superior vena cava syndrome (SVCS) is caused by obstruction to the blood flow through this vein. Indwelling central venous devices, such as cardiac pacemakers and haemodialysis catheters have emerged as the most common benign aetiology of SVCS. SVCS is particularly severe in patients with end-stage renal disease who require continuous renal replacement therapy plus infusion therapy. The presence of SVCS results in a reduction of available venous access for affected patients. Therefore, venous access plays a crucial role in the management of these patients. The importance of dealing with vascular access (VA) in critical patients with these conditions cannot be overstated. This case describes an 81-year-old man with respiratory failure who had end-stage renal disease complicated with SVCS. Using ultrasound-guided puncture, we inserted a peripherally inserted central catheter (PICC) into the superficial femoral vein to meet his infusion requirements in intensive care. After successful placement, the catheter tip position was adjusted using imaging to position the tip relative to the haemodialysis catheter. Whenever patients with severe renal dysfunction are treated, central veins should be preserved. Safe PICC access is possible via the superficial femoral vein to protect the last central VA for rational use. This meets urgent needs for infusion and deserves promotion.

Associations of Iron Sucrose and Intradialytic Blood Pressure.

RATIONALE & OBJECTIVE: Intradialytic hypotension and intradialytic hypertension are associated with morbidity and mortality in hemodialysis (HD). Many factors can contribute to intra-HD blood pressure (BP) changes, such as drugs with vasoactive properties that can destabilize an already tenuous BP. Intravenous iron sucrose is commonly administered to correct iron deficiency; however, its reported associations with altered hemodynamics have not been consistent. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 950 outpatients receiving maintenance HD. EXPOSURE: Iron sucrose administered during HD. OUTCOME: Intradialytic hypotension, intradialytic hypertension, systolic blood pressure parameters. ANALYTICAL APPROACH: Unadjusted and adjusted Poisson and linear repeated measures regression models. RESULTS: The mean age of patients included in the study was 53±22 years, 43% were female, and 38% were Black. Mean pre-HD SBP was 152±26 (SD) mm Hg. At baseline, the patients who received higher doses of iron sucrose tended to have diabetes, have longer HD sessions, and have a higher frequency of erythropoiesis-stimulating agent use, compared with those who did not receive iron sucrose. In adjusted models, higher doses of iron sucrose were associated with an 11% lower rate of intradialytic hypotension (incidence rate ratio [IRR] for iron sucrose≥100mg vs 0 mg, 0.89 [95% CI, 0.85-0.94]). In adjusted analyses, the administration of higher doses of iron sucrose during HD was associated with intradialytic hypertension (IRR for iron sucrose≥100mg vs 0 mg, 1.07 [95% CI, 1.04-1.10]). LIMITATIONS: Nonavailability of the precise iron sucrose formulation (volume), laboratory data for each HD session, and outpatient medications. Objective measures of volume status, home medications, and symptom data were not recorded in this study. CONCLUSIONS: We observed an independent association of intravenous iron sucrose administration during HD with a lower risk of intradialytic hypotension and higher risk of intradialytic hypertension. Future studies to better understand the mechanisms underlying these associations are warranted. PLAIN-LANGUAGE SUMMARY: Intradialytic hypotension and intradialytic hypertension are common among patients on hemodialysis, and they are associated with morbidity and mortality. Although many factors may contribute to these risks, medications administered during hemodialysis play an important role. We studied the significance of the intravenous iron sucrose used to treat iron deficiency and the impact it may have on blood pressure during dialysis. In our study of 950 outpatient hemodialysis patients, we observed that administration of iron sucrose was associated with higher systolic blood pressure (during and after hemodialysis sessions) as well as a lower risk of intradialytic hypotension. We also observed that higher doses of iron sucrose are associated with the development of intradialytic hypertension.

Peritoneal Dialysis-Associated Peritonitis Trends Using Medicare Claims Data, 2013-2017.

RATIONALE & OBJECTIVE: The occurrence and consequences of peritoneal dialysis (PD)-associated peritonitis limit its use in populations with kidney failure. Studies of large clinical populations may enhance our understanding of peritonitis. To facilitate these studies we developed an approach to measuring peritonitis rates using Medicare claims data to characterize peritonitis trends and identify its clinical risk factors. STUDY DESIGN: Retrospective cohort study of PD-associated peritonitis. SETTING & PARTICIPANTS: US Renal Data System standard analysis files were used for claims, eligibility, modality, and demographic information. The sample consisted of patients receiving PD treated at some time between 2013 and 2017 who were covered by Medicare fee-for-service (FFS) insurance with paid claims for dialysis or hospital services. EXPOSURES/PREDICTORS: Peritonitis risk was characterized by year, age, sex, race, ethnicity, vintage of kidney replacement therapy, cause of kidney failure, and prior peritonitis episodes. OUTCOME: The major outcome was peritonitis, identified using ICD-9 and ICD-10 diagnosis codes. Closely spaced peritonitis claims (30 days) were aggregated into 1 peritonitis episode. ANALYTICAL APPROACH: Patient-level risk factors for peritonitis were modeled using Poisson regression. RESULTS: We identified 70,271 peritonitis episodes from 396,289 peritonitis claims. Although various codes were used to record an episode of peritonitis, none was used predominantly. Peritonitis episodes were often identified by multiple aggregated claims, with the mean and median claims per episode being 5.6 and 2, respectively. We found 40% of episodes were exclusively outpatient, 9% exclusively inpatient, and 16% were exclusively based on codes that do not clearly distinguish peritonitis from catheter infections/inflammation ("catheter codes"). The overall peritonitis rate was 0.54 episodes per patient-year (EPPY). The rate was 0.45 EPPY after excluding catheter codes and 0.35 EPPY when limited to episodes that only included claims from nephrologists or dialysis providers. The peritonitis rate declined by 5%/year and varied by patient factors including age (lower rates at higher ages), race (Black > White>Asian), and prior peritonitis episodes (higher rate with each prior episode). LIMITATIONS: Coding heterogeneity indicates a lack of standardization. Episodes based exclusively on catheter codes could represent false positives. Peritonitis episodes were not validated against symptoms or microbiologic data. CONCLUSIONS: PD-associated peritonitis rates decline over time and were lower among older patients. A claims-based approach offers a promising framework for the study of PD-associated peritonitis.

Sex Disparity in Cause-Specific and All-Cause Mortality Among Incident Dialysis Patients.

RATIONALE & OBJECTIVE: Early mortality rates of female patients receiving dialysis have been, at times, observed to be higher than rates among male patients. The differences in cause-specific mortality between male and female incident dialysis patients with kidney failure are not well understood and were the focus of this study. STUDY DESIGN: Retrospective cohort study. SETTING & PARTICIPANTS: Incident patients who had initiated dialysis in Australia and New Zealand in 1998-2018. EXPOSURE: Sex. OUTCOMES: Cause-specific and all-cause mortality while receiving dialysis, censored for kidney transplant. ANALYTICAL APPROACH: Adjusted cause-specific proportional hazards models, focusing on the first 5 years following initiation of dialysis. RESULTS: Among 53,414 patients (20,876 [39%] female) followed for a median period of 2.8 (IQR, 1.3-5.2) years, 27,137 (51%) died, with the predominant cause of death attributed to cardiovascular disease (18%), followed by dialysis withdrawal (16%). Compared with male patients, female patients were more likely to die in the first 5 years after dialysis initiation (adjusted hazard ratio [AHR], 1.08 [95% CI, 1.05-1.11]). Even though female patients experienced a lower risk of cardiovascular disease-related mortality (AHR, 0.93 [95% CI, 0.89-0.98]) than male patients, they experienced a greater risk of infection-related (AHR, 1.20 [95% CI, 1.10-1.32]) and dialysis withdrawal-related (AHR, 1.19 [95% CI, 1.13-1.26]) mortality. LIMITATIONS: Possibility of residual and unmeasured confounders. CONCLUSIONS: Compared with male patients, female patients had a higher risk of all-cause mortality in the first 5 years after dialysis initiation, a difference driven by higher rates of mortality from infections and dialysis withdrawals. These findings may inform the study of sex differences in mortality in other geographic settings.

Calciphylaxis and Kidney Disease: A Review.

Calciphylaxis is a life-threatening complication most often associated with chronic kidney disease that occurs as a result of the deposition of calcium in dermal and adipose microvasculature. However, this condition may also be seen in patients with acute kidney injury. The high morbidity and mortality rates associated with calciphylaxis highlight the importance to correctly diagnose and treat this condition. However, calciphylaxis remains a diagnosis that may be clinically challenging to make. Here, we review the literature on uremic calciphylaxis with a focus on its pathophysiology, clinical presentation, advances in diagnostic tools, and treatment strategies. We also discuss the unique histopathological features of calciphylaxis and contrast it with those of other forms of general vessel calcification. This review emphasizes the need for multidisciplinary collaboration including nephrology, dermatology, and palliative care to ultimately provide the best possible care to patients with calciphylaxis.

Association of Retinal Age Gap and Risk of Kidney Failure: A UK Biobank Study.

RATIONALE & OBJECTIVE: The incidence of kidney failure is known to increase with age. We have previously developed and validated the use of retinal age based on fundus images as a biomarker of aging. However, the association of retinal age with kidney failure is not clear. We investigated the association of retinal age gap (the difference between retinal age and chronological age) with future risk of kidney failure. STUDY DESIGN: Prospective cohort study. SETTING & PARTICIPANTS: 11,052 UK Biobank study participants without any reported disease for characterizing retinal age in a deep learning algorithm. 35,864 other participants with retinal images and no kidney failure were followed to assess the association between retinal age gap and the risk of kidney failure. EXPOSURE: Retinal age gap, defined as the difference between model-based retinal age and chronological age. OUTCOME: Incident kidney failure. ANALYTICAL APPROACH: A deep learning prediction model used to characterize retinal age based on retinal images and chronological age, and Cox proportional hazards regression models to investigate the association of retinal age gap with incident kidney failure. RESULTS: After a median follow-up period of 11 (IQR, 10.89-11.14) years, 115 (0.32%) participants were diagnosed with incident kidney failure. Each 1-year greater retinal age gap at baseline was independently associated with a 10% increase in the risk of incident kidney failure (HR, 1.10 [95% CI, 1.03-1.17]; P=0.003). Participants with retinal age gaps in the fourth (highest) quartile had a significantly higher risk of incident kidney failure compared with those in the first quartile (HR, 2.77 [95% CI, 1.29-5.93]; P=0.009). LIMITATIONS: Limited generalizability related to the composition of participants in the UK Biobank study. CONCLUSIONS: Retinal age gap was significantly associated with incident kidney failure and may be a promising noninvasive predictive biomarker for incident kidney failure.

Antimicrobial Photodynamic Therapy in the Nasal Decolonization of Maintenance Hemodialysis Patients: A Pilot Randomized Trial.

RATIONALE & OBJECTIVE: Infections are an important cause of mortality among patients receiving maintenance hemodialysis. Staphylococcus aureus is a frequent etiological agent, and previous nasal colonization is a risk factor for infection. Repeated antimicrobial decolonization reduces infection in this population but can induce antibiotic resistance. We compared photodynamic therapy, a promising bactericidal treatment that does not induce resistance, to mupirocin treatment among nasal carriers of S aureus. STUDY DESIGN: Randomized controlled pilot study. SETTING & PARTICIPANTS: 34 patients receiving maintenance hemodialysis who had nasal carriage of S aureus. INTERVENTIONS: Patients were randomly assigned to decolonization with a single application of photodynamic therapy (wavelength of 660nm, 400mW/cm2, 300 seconds, methylene blue 0.01%) or with a topical mupirocin regimen (twice a day for 5 days). OUTCOME: Nasal swabs were collected at time 0 (when the carrier state was identified), directly after treatment completion, 1 month after treatment, and 3 months after treatment. Bacterial isolates were subjected to proteomic analysis to identify the species present, and antimicrobial susceptibility was characterized. RESULTS: All 17 participants randomized to photodynamic therapy and 13 of 17 (77%) randomized to mupirocin were adherent to treatment. Directly after treatment was completed, 12 participants receiving photodynamic therapy (71%) and 13 participants treated with mupirocin (77%) had cultures that were negative for S aureus (risk ratio, 0.92 [95% CI, 0.61-1.38]; P=0.9). Of the patients who had negative cultures directly after completion of photodynamic therapy, 67% were recolonized within 3 months. There were no adverse events in the photodynamic therapy group. LIMITATIONS: Testing was restricted to assessing nasal colonization; infectious complications were not assessed. CONCLUSIONS: Photodynamic therapy is a feasible approach to treating nasal carriage of S aureus. Future larger studies should be conducted to determine whether photodynamic therapy is equivalent to the standard of care with mupirocin. FUNDING: Government grant (National Council for Scientific and Technological Development process 3146682020-9). TRIAL REGISTRATION: Registered at ClinicalTrials.gov with study number NCT04047914.

Association of the Urine-to-Plasma Urea Ratio With CKD Progression.

RATIONALE & OBJECTIVES: The urine-to-plasma (U/P) ratio of urea is correlated with urine-concentrating capacity and associated with progression of autosomal dominant polycystic kidney disease. As a proposed biomarker of tubular function, we hypothesized that the U/P urea ratio would also be associated with progression of more common forms of chronic kidney disease (CKD). STUDY DESIGN: Observational cohort study. SETTING & PARTICIPANTS: 3,723 adults in the United States with estimated glomerular filtration rate (eGFR) of 20-70 mL/min/1.73 m2, enrolled in the Chronic Renal Insufficiency Cohort (CRIC) Study. EXPOSURE: U/P urea ratio, calculated from 24-hour urine collections and plasma samples at baseline. OUTCOME: Associations of U/P urea ratio with eGFR slope, initiation of kidney replacement therapy (KRT), and CKD progression, defined as 50% decline in eGFR or incident KRT. ANALYTICAL APPROACH: Multivariable linear mixed-effects models tested associations with eGFR slope. Cox proportional hazards models tested associations with dichotomous CKD outcomes. RESULTS: The median U/P urea ratio was 14.8 (IQR, 9.5-22.2). Compared with participants in the highest U/P urea ratio quintile, those in the lowest quintile had a greater eGFR decline by 1.06 mL/min/1.73 m2 per year (P < 0.001) over 7.0 (IQR, 3.0-11.0) years of follow-up observation. Each 1-SD lower natural log-transformed U/P urea ratio was independently associated with CKD progression (HR, 1.22 [95% CI, 1.12-1.33]) and incident KRT (HR, 1.22 [95% CI, 1.10-1.33]). Associations differed by baseline eGFR (P interaction = 0.009). Among those with an eGFR ≥30 mL/min/1.73 m2, each 1-SD lower in ln(U/P urea ratio) was independently associated with CKD progression (HR, 1.30 [95% CI, 1.18-1.45]), but this was not significant among those with eGFR <30 mL/min/1.73 m2 (HR, 1.00 [95% CI, 0.84-1.20]). LIMITATIONS: Possibility of residual confounding. Single baseline 24-hour urine collection for U/P urea ratio. CONCLUSIONS: In a large and diverse cohort of patients with common forms of CKD, U/P urea was independently associated with disease progression and incident kidney failure. Associations were not significant among those with advanced CKD at baseline.

Patient and Clinician Perspectives on Shared Decision Making in Vascular Access Selection: A Qualitative Study.

RATIONALE & OBJECTIVE: Collaborative approaches to vascular access selection are being increasingly encouraged to elicit patients' preferences and priorities where no unequivocally superior choice exists. We explored how patients, their caregivers, and clinicians integrate principles of shared decision making when engaging in vascular access discussions. STUDY DESIGN: Qualitative description. SETTING & PARTICIPANTS: Semistructured interviews with a purposive sample of patients, their caregivers, and clinicians from outpatient hemodialysis programs in Alberta, Canada. ANALYTICAL APPROACH: We used a thematic analysis approach to inductively code transcripts and generate themes to capture key concepts related to vascular access shared decision making across participant roles. RESULTS: 42 individuals (19 patients, 2 caregivers, 21 clinicians) participated in this study. Participants identified how access-related decisions follow a series of major decisions about kidney replacement therapy and care goals that influence vascular access preferences and choice. Vascular access shared decision making was strengthened through integration of vascular access selection with dialysis-related decisions and timely, tailored, and balanced exchange of information between patients and their care team. Participants described how opportunities to revisit the vascular access decision before and after dialysis initiation helped prepare patients for their access and encouraged ongoing alignment between patients' care priorities and treatment plans. Where shared decision making was undermined, hemodialysis via a catheter ensued as the most readily available vascular access option. LIMITATIONS: Our study was limited to patients and clinicians from hemodialysis care settings and included few caregiver participants. CONCLUSIONS: Findings suggest that earlier, or upstream, decisions about kidney replacement therapies influence how and when vascular access decisions are made. Repeated vascular access discussions that are integrated with other higher-level decisions are needed to promote vascular access shared decision making and preparedness.

SARS-CoV-2 Vaccine Effectiveness and Breakthrough Infections Among Patients Receiving Maintenance Dialysis.

RATIONALE & OBJECTIVE: SARS-CoV-2 vaccine effectiveness and immunogenicity threshold associated with protection against COVID-19-related hospitalization or death in the dialysis population are unknown. STUDY DESIGN: Retrospective, observational study. SETTING & PARTICIPANTS: Adult patients without COVID-19 history receiving maintenance dialysis through a national dialysis provider and treated between February 1 and December 18, 2021, with follow-up through January 17, 2022. PREDICTOR: SARS-CoV-2 vaccination status. OUTCOMES: All SARS-CoV-2 infections, composite of hospitalization or death following COVID-19. ANALYTICAL APPROACH: Logistic regression was used to determine COVID-19 case rates and vaccine effectiveness. RESULTS: Of 16,213 patients receiving dialysis during the study period, 12,278 (76%) were fully vaccinated, 589 (4%) were partially vaccinated, and 3,346 (21%) were unvaccinated by the end of follow-up. Of 1,225 COVID-19 cases identified, 550 (45%) occurred in unvaccinated patients, and 891 (73%) occurred during the Delta variant-dominant period. Between the pre-Delta period and the Delta-dominant period, vaccine effectiveness rates against a severe COVID-19-related event (hospitalization or death) were 84% and 70%, respectively. In the subset of 3,202 vaccinated patients with at least one anti-spike immunoglobulin G (IgG) assessment, lower anti-spike IgG levels were associated with higher case rates per 10,000 days and higher adjusted hazard ratios for infection and COVID-19-related hospitalization or death. LIMITATIONS: Observational design, residual biases, and confounding may exist. CONCLUSIONS: Among maintenance dialysis patients, SARS-CoV-2 vaccination was associated with a lower risk of COVID-19 diagnosis and associated hospitalization or death. Among vaccinated patients, a low anti-spike IgG level is associated with worse COVID-19-related outcomes.

Peritoneal Dialysis Prescription and Adequacy in Clinical Practice: Core Curriculum 2023.

As the global prevalence of peritoneal dialysis (PD) continues to grow, practitioners must be equipped with prescribing strategies that focus on the needs and preferences of patients. PD is an effective form of kidney replacement therapy that offers numerous benefits to patients, including more flexibility in schedules compared with in-center hemodialysis (HD). Additional benefits of PD include salt and water removal without significant changes in patient hemodynamics. This continuous yet gentle removal of solutes and fluid is associated with better-preserved residual kidney function. Unfortunately, sometimes these advantages are overlooked at the expense of an emphasis on achieving small solute clearance targets. A more patient-centered approach emphasizes the importance of individualized treatment, particularly when considering incremental PD and other prescriptions that align with lifestyle preferences. In shifting the focus from small solute clearance targets to patient needs and clinical goals, PD remains an attractive, patient-centered form of kidney replacement therapy.

Integrated proteome and malonylome analyses reveal the potential meaning of TLN1 and ACTB in end-stage renal disease.

BACKGROUND: End-stage renal disease (ESRD) is a condition that is characterized by the loss of kidney function. ESRD patients suffer from various endothelial dysfunctions, inflammation, and immune system defects. Lysine malonylation (Kmal) is a recently discovered post-translational modification (PTM). Although Kmal has the ability to regulate a wide range of biological processes in various organisms, its specific role in ESRD is limited. METHODS: In this study, the affinity enrichment and liquid chromatography-tandem mass spectrometry (LC-MS/MS) techniques have been used to create the first global proteome and malonyl proteome (malonylome) profiles of peripheral blood mononuclear cells (PBMCs) from twenty patients with ESRD and eighty-one controls. RESULTS: On analysis, 793 differentially expressed proteins (DEPs) and 12 differentially malonylated proteins (DMPs) with 16 Kmal sites were identified. The Rap1 signaling pathway and platelet activation pathway were found to be important in the development of chronic kidney disease (CKD), as were DMPs TLN1 and ACTB, as well as one malonylated site. One conserved Kmal motif was also discovered. CONCLUSIONS: These findings provided the first report on the Kmal profile in ESRD, which could be useful in understanding the potential role of lysine malonylation modification in the development of ESRD.

Post-kidney transplant body mass index trajectories are associated with graft loss and mortality.

BACKGROUND: Early post-kidney transplantation (KT) changes in physiology, medications, and health stressors likely impact body mass index (BMI) and likely impact all-cause graft loss and mortality. METHODS: We estimated 5-year post-KT (n = 151 170; SRTR) BMI trajectories using an adjusted mixed effects model. We estimated long-term mortality and graft loss risks by 1-year BMI change quartile (decrease [1st quartile]: change < -.07 kg/m2 /month; stable [2nd quartile]: -.07 ≤ change ≤ .09 kg/m2 /month; increase [3rd, 4th quartile]: change > .09 kg/m2 /month) using adjusted Cox proportional hazards models. RESULTS: BMI increased in the 3 years post-KT (.64 kg/m2 /year, 95% CI: .63, .64) and decreased in years 3-5 (-.24 kg/m2 /year, 95% CI: -.26, -.22). 1-year post-KT BMI decrease was associated with elevated risks of all-cause mortality (aHR = 1.13, 95% CI: 1.10-1.16), all-cause graft loss (aHR = 1.13, 95% CI: 1.10-1.15), death-censored graft loss (aHR = 1.15, 95% CI: 1.11-1.19), and mortality with functioning graft (aHR = 1.11, 95% CI: 1.08-1.14). Among recipients with obesity (pre-KT BMI≥30 kg/m2 ), BMI increase was associated with higher all-cause mortality (aHR = 1.09, 95% CI: 1.05-1.14), all-cause graft loss (aHR = 1.05, 95% CI: 1.01-1.09), and mortality with functioning graft (aHR = 1.10, 95% CI: 1.05-1.15) risks, but not death-censored graft loss risks, relative to stable weight. Among individuals without obesity, BMI increase was associated with lower all-cause graft loss (aHR = .97, 95% CI: .95-.99) and death-censored graft loss (aHR = .93, 95% CI: .90-.96) risks, but not all-cause mortality or mortality with functioning graft risks. CONCLUSIONS: BMI increases in the 3 years post-KT, then decreases in years 3-5. BMI loss in all adult KT recipients and BMI gain in those with obesity should be carefully monitored post-KT.

Prevalence of obstructive sleep apnea in patients with chronic kidney disease: a hospital-based study.

BACKGROUND: Chronic kidney disease (CKD) is has been rising over the past few years, and obstructive sleep apnea (OSA) is a prevalent comorbidity in this population. AIM: To determine the prevalence of OSA in patients with chronic kidney disease stages I-V and end-stage renal disease (ESRD). METHODS: Patients with CKD of varying grades and ESRD routinely visiting outpatient nephrology clinic or admitted in department of nephrology were included in the study. Stages I-III were categorized as early stages of CKD and stages IV-V and ESRD as late stages of CKD. Patients were categorized into a high risk group based on STOP-BANG and Berlin questionnaires. Patients who were high risk were subjected to in-hospital overnight level III polysomnography. Student's independent t-test and analysis of variance (ANOVA) were employed for the comparison of continuous variables. Chi-square test and Fisher's exact test, as appropriate, were used for the comparison of categorical variables. RESULTS: Of 111 patients, 46 (41%) were found to have OSA. Of these patients, 15 (33%) had mild OSA (AHI 5-14/h), 13 (28%) had moderate OSA (15-29/h), and 18 (39%) had severe OSA (AHI ≥ 30/h). Overall, 31% of patients in the early stage of CKD and 45% in the late stage were found to have OSA. CONCLUSION: This study demonstrated a high prevalence of OSA in patients with CKD when compared to the general population affecting both genders equally. The risk of OSA was higher in the advanced stages of CKD compared to the early stages, and dialysis had no effect on prevalence. Since OSA increases the cardiovascular morbidity in CKD the leading cause of death in these patients, early diagnosis and treatment of OSA may have promise to affect the mortality.

Factors associated with quality of life in patients with kidney failure managed conservatively and with dialysis: a cross-sectional study.

BACKGROUND: Later stage chronic kidney disease (CKD) is associated with poorer self-perceived health-related quality of life (HRQOL), a major consideration for many patients. Psychological factors such as depression and anxiety have been linked with poorer HRQOL. We aimed to determine if anxiety or depressive symptoms are significantly associated with self-perceived health-related quality of life, in patients with CKD Stage 5. The secondary aim was to determine which patient-associated factors are associated with HRQOL in patients with CKD Stage 5. METHODS: This retrospective cross-sectional study included patients that attended the St George Hospital Kidney Supportive Care (KSC) clinic between 1 and 2015 and 30 June 2022 with CKD Stage 5 (either conservatively-managed or receiving dialysis). Patients completed surveys of their functional 'domains' and quality of life (EQ-5D-5L) and symptom surveys (IPOS-Renal) at their first visit. We performed multivariable linear regression analysis with the outcome of interest being HRQOL, measured using the EQ-VAS, a continuous 100-point scale, for patients undergoing conservative management or dialysis. Pre-specified variables included age, sex, eGFR (for those conservatively-managed), "feeling depressed" (IPOS-Renal), "feeling anxious" (IPOS-Renal) and "anxiety/depression" (EQ-5D-5L). RESULTS: We included 339 patients. 216 patients received conservative kidney management (CKM) and 123 patients received dialysis. Patients receiving CKM were significantly older than those on dialysis, (median age 83 years vs. 73 years, p < 0.001). For conservatively-managed patients, variables independently associated with poorer EQ-VAS were difficulty performing usual activities (EQ-5D-5L), drowsiness (IPOS-Renal) and shortness of breath (IPOS-Renal). For patients receiving dialysis, variables that were independently associated with poorer EQ-VAS were reduced ability to perform self-care (EQ-5D-5L) and lack of energy (IPOS-Renal). Anxiety and depressive symptoms were not significantly associated with poorer EQ-VAS for either group of patients. CONCLUSIONS: Symptoms associated with reduced HRQOL include shortness of breath, drowsiness and impaired functional ability. Optimization of multidisciplinary teams focusing on these issues are likely to be of benefit.

New Insights on the Role of Marinobufagenin from Bench to Bedside in Cardiovascular and Kidney Diseases.

Marinobufagenin (MBG) is a member of the bufadienolide family of compounds, which are natural cardiac glycosides found in a variety of animal species, including man, which have different physiological and biochemical functions but have a common action on the inhibition of the adenosine triphosphatase sodium-potassium pump (Na+/K+-ATPase). MBG acts as an endogenous cardiotonic steroid, and in the last decade, its role as a pathogenic factor in various human diseases has emerged. In this paper, we have collated major evidence regarding the biological characteristics and functions of MBG and its implications in human pathology. This review focused on MBG involvement in chronic kidney disease, including end-stage renal disease, cardiovascular diseases, sex and gender medicine, and its actions on the nervous and immune systems. The role of MBG in pathogenesis and the development of a wide range of pathological conditions indicate that this endogenous peptide could be used in the future as a diagnostic biomarker and/or therapeutic target, opening important avenues of scientific research.

Association between NLRP3 rs10754558 and CARD8 rs2043211 Variants and Susceptibility to Chronic Kidney Disease.

Nod-like receptor protein 3 (NLRP3) is a multi-protein complex belonging to the innate immune system, whose activation by danger stimuli promotes inflammatory cell death. Evidence supports the crucial role of NLRP3 inflammasome activation in the transition of acute kidney injury to Chronic Kidney Disease (CKD), by promoting both inflammation and fibrotic processes. Variants of NLRP3 pathway-related genes, such as NLRP3 itself and CARD8, have been associated with susceptibility to different autoimmune and inflammatory diseases. In this study, we investigated for the first time the association of functional variants of NLRP3 pathway-related genes (NLRP3-rs10754558, CARD8-rs2043211), with a susceptibility to CKD. A cohort of kidney transplant recipients, dialysis and CKD stage 3-5 patients (303 cases) and a cohort of elderly controls (85 subjects) were genotyped for the variants of interest and compared by using logistic regression analyses. Our analysis showed a significantly higher G allele frequency of the NLRP3 variant (67.3%) and T allele of the CARD8 variant (70.8%) among cases, compared with the control sample (35.9 and 31.2%, respectively). Logistic regressions showed significant associations (p < 0.001) between NLRP3 and CARD8 variants and cases. Our results suggest that the NLRP3 rs10754558 and CARD8 rs2043211 variants could be associated with a susceptibility to CKD.