Clinical Kidney Journal最新文献

Autosomal dominant polycystic kidney disease (ADPKD) is the most common monogenic cause of kidney failure globally, and a significant cause of morbidity and mortality. It is now recognized that it may result from both major and minor genes with associated differences in disease penetrance, symptom burden and clinical outcomes. Genetic testing is now readily available to discriminate between different genotypes and is being increasingly utilized for diagnostic and prognostic indications. In this short review, we summarize the reasons why testing should become part of standard care for ADPKD patients where available and highlight some current limitations and challenges to testing. Defining the genetic landscape in ADPKD for all ethnic groups will be key to the future development and deployment of individualized patient-centered management in this condition.

Background: Cystinuria is a rare autosomal recessive disorder characterized by impaired renal reabsorption of cystine and dibasic amino acids, leading to recurrent nephrolithiasis. While dietary salt and protein restriction are commonly recommended, evidence supporting their effectiveness in reducing urinary cystine excretion is limited. This study investigated whether intra-individual changes in dietary salt and protein intake are associated with changes in cystine excretion over time.

Methods: We conducted a retrospective cohort study of 41 adult patients with recurrent cystine stones treated at a tertiary kidney stone clinic between 2004 and 2023. All patients underwent five 24-hour urine collections at intervals of 6-12 months. Urinary sodium and urea excretions were used as surrogates for salt and protein intake, respectively. Mixed-effects linear regression models assessed within-person associations between dietary intake and urinary cystine excretion, adjusting for age, sex, and time.

Results: Cystine excretion showed considerable intra-individual variability (intraclass correlation coefficient: 0.457). An increase in urinary urea of 3.5 g/24 h (reflecting ∼10 g/day higher protein intake) was associated with a 164 µmol/24 h increase in cystine excretion (95% CI: 57 to 271, P = .003). In contrast, a 17 mmol/24 h increase in urinary sodium (∼1 g/day salt intake) was associated with a non-significant 46 µmol/24 h increase in cystine excretion (95% CI: -5 to 97, P = .081).

Conclusions: Protein intake is moderately associated with urinary cystine excretion, whereas salt intake has minimal effect. These findings suggest that, while protein moderation may contribute to cystine reduction, fluid intake and urine alkalinization remain the primary determinants of urinary cystine levels.

Background: Intradialytic hypotension (IDH) is a serious complication of chronic hemodialysis (HD). BestShape is a novel artificial intelligence-driven system developed recently for real-time prediction of IDH. This study aimed to report the clinical results and health-economic benefits following the implementation of BestShape.

Methods: Medical records from two institutions in Taiwan that incorporated BestShape into all HD practices were retrospectively reviewed. Data from HD sessions from January 2020 to December 2023, following BestShape implementation, constituted the "BestShape group." Data from January 2016 through the end of 2019 served as the historical control group. The primary outcome was IDH frequency, and secondary outcomes were rates of cardiopulmonary resuscitation (CPR), falls, mortality, medical personnel satisfaction, and estimated cost reduction.

Results: In total, 213 071 HD sessions of 18 141 patients were included (BestShape 152 792 sessions; control 60 279 sessions). The mean monthly IDH rate significantly reduced from 27% in 2019 to 21% in 2023 (P < .001). The need for CPR during dialysis decreased from eight to three times per month, and post-dialysis falls decreased from 21 to seven times. The estimated annual cost savings by implementing BestShape were USD 115 658. The mortality rate during HD was not significantly different before and after BestShape implementation (8% vs 9.3%, P = .260). Medical personnel expressed satisfaction with BestShape, with a mean satisfaction score of 86.

Conclusion: Preliminary clinical data show BestShape is associated with reductions in IDH, CPR, and falls in patients undergoing HD, and a reduction in healthcare costs and high medical personnel satisfaction.

The debate over whether to use age-adapted or age-independent estimated glomerular filtration rate (eGFR) cut-offs for diagnosing chronic kidney disease (CKD) reflects a fundamental tension between physiological understanding and clinical pragmatism. Age-adapted proponents highlight robust evidence that GFR declines naturally with age, with many healthy older adults falling below the traditional 60 ml/min/1.73 m² threshold. They argue that fixed cut-offs risk overdiagnosing CKD in the elderly, potentially leading to unnecessary anxiety and treatment, while underrecognizing risk in younger individuals whose GFRs are abnormal for their age. Physiological and longitudinal studies support this view, suggesting age-specific percentiles may better reflect true pathology. Conversely, advocates for age-independent thresholds emphasize that age-related GFR decline is not benign. Large epidemiological studies show that older adults with an eGFR of 45-59 ml/min/1.73 m² are at increased risk of kidney failure, cardiovascular events and mortality, even in the absence of albuminuria. They caution that redefining CKD based on age could exclude high-risk older adults from beneficial therapies and research and that 'healthy' reference populations may harbour undiagnosed disease. A balanced approach recognizes the physiological realities of aging while not ignoring the clinical risks associated with reduced kidney function in older adults. Individualized risk prediction tools and shared decision-making can help tailor diagnosis and management. Ultimately, moving beyond arbitrary thresholds toward a patient-centred, risk-based strategy may best serve individuals across their lifespans, ensuring that CKD diagnosis and care are both scientifically sound and clinically meaningful.

Introduction: Crescentic glomerulonephritis (CrGN) with rapidly progressive renal function loss necessitates prompt pathology diagnosis and treatment. Non-invasive biomarkers are crucial in cases where renal biopsy is unavailable or unsuitable. Urinary proteomics, particularly data-independent acquisition (DIA) proteomics, might provide potential indicators.

Methods: We recruited crescentic nephritis proved by renal biopsy at Peking Union Medical College Hospital (PUMCH) from May 2022 to April 2023 and age-matched nephritis, acute kidney injury (AKI), and health controls. The CrGN group is the patients with extensive glomerular crescents over 50%. We performed liquid chromatography with tandem mass spectrometry analysis to identify differentially expressed proteins (DEPs), ingenuity pathway analysis (IPA), and the proteome map for significant pathways and crucial proteins among patients and controls, then validated using enzyme-linked immunosorbent assay analysis.

Results: We enrolled a total of 137 participants, 55 in the proteomics cohort [15 CrGN (Type I: n = 1, II: n = 3, III: n = 11), 10 AKI, 15 non-crescentic nephritis, 15 healthy controls] and 82 in the validation cohort (33 CrGN, 6 AKI, 43 nephritis). Males occupied 42.3%, and the average age was 48 years of age. IPA analysis showed that neutrophil degranulation and complement cascade were the top two pathways in CrGN but not in the healthy and nephritis groups. Pathway analysis revealed activation of the neddylation pathway in CrGN compared to AKI patients. After integrating the DEPs among three groups via the Venn plot, we observed eight DEPs significantly associated with the CrGN, among which Coagulation factor V (F5), Phospholipid transfer protein (PLTP), and alcohol dehydrogenase 1C were significant proteins. The area under the curve values of F5 and PLTP in the validation cohort for predicting CrGN were 0.831 and 0.780 (P < .001).

Conclusion: By non-invasive urine proteomics, the new biomarkers F5/UCr and PLTP/UCr hold promise in identifying the CrGN patient.

Background and hypothesis: Intradialytic hypotension (IDH) is a common complication during hemodialysis, associated with immediate and long-term risks. Current monitoring methods lack timely warning signals for preemptive intervention. Continuous non-invasive measurement of blood pressure providing real-time insights into hemodynamic changes might enable the early detection of impending IDH. Pulse arrival time (PAT), which can be measured non-invasively and continuously by electrocardiogram (ECG) and photoplethysmography (PPG), is inversely correlated with blood pressure and might serve as such. Thus, this study explores the feasibility of using PAT to track blood pressure changes in end-stage renal disease patients undergoing hemodialysis.

Methods: A feasibility study was conducted with 44 patients [mean age 64.9 (18.1 SD) years] undergoing hemodialysis, collecting data at the Klinikum rechts der Isar of the Technical University of Munich, School of Medicine. The PAT was determined by an algorithm for detecting the R-wave in the ECG and the beginning of the pulse curve in the PPG. The study focused on changes in PAT and blood pressure during three predefined time periods of 1 hour during dialysis. Statistical analysis included equivalence testing using the TOST (two one-sided t-tests) approach, correlation analysis, and classification analysis.

Results: Patients' mean systolic blood pressure (BP) was 137 (30.1 SD) mmHg, diastolic BP 68.4 (18.4 SD) mmHg and PAT 233 (42.3 SD) ms. The study revealed an inverse association between PAT and BP changes, demonstrating significant correlations [systolic/diastolic blood pressures (SBP/DBP) r = -0.45, P < .001; DBP r = -0.25, P = .003] and equivalence (inverted changes in PAT and SBP (P1 = .002 and P2 = .013) and DBP (P1 < .001 and P2 = .037), respectively). Classification analysis using relative PAT changes showed moderate results for categorizing patients as SBP decliners, risers, or stable, with an F1-score of 0.67 (sensitivity 62.7%; specificity 70.9%) and an area under the curve of 0.70 from receiver operating characteristic analysis.

Conclusions: The study demonstrates that tracking BP changes using PAT as a non-invasive method in hemodialysis patients is feasible. However, the reliability of PAT measurements appears to vary among patients, indicating that this method may not be universally applicable. The observed inverse association between PAT and BP changes, especially during the start to middle phase of dialysis, highlights the potential of this technique to complement traditional monitoring methods. These exploratory findings open avenues for further research to validate the utility of PAT, particularly in predicting IDH episodes and assessing its behavior in scenarios of low BP or minimal variations.

Background: Gitelman syndrome (GS) is a rare inherited salt-losing tubulopathy caused by dysfunction of the thiazide-sensitive sodium-chloride cotransporter (NCC). Hyperuricemia is frequently observed in patients with GS, yet its risk factors and associations with GS remain unclear. This study aimed to investigate the percentage, clinical characteristics, and genetic mechanisms in GS patients with hyperuricemia.

Methods: We reanalyzed the GS cohort at Peking Union Medical College Hospital, investigated the baseline clinical, laboratory, and genetic data of GS patients, and utilized the Illumina Human Asian Screening Array-24+v1.0 gene chip and IMPUTE2 for single nucleotide polymorphism (SNP) analysis.

Results: The average serum uric acid of 132 GS patients was 352.3 ± 96.9 μmol/l (5.9 ± 1.6 mg/dl), with 21.2% hyperuricemia [mean 486.1 μmol/l (8.2 mg/dl)] and two cases of gout. The GS patients with hyperuricemia had higher body mass index (BMI) (24.3 ± 3.9 vs 21.7 ± 3.5 kg/m², P = .001), lower fractional excretion of uric acid (FEUA) (median 4.22% vs 6.17%, P < .001), and urinary calcium/creatinine ratio (0.05 vs 0.12 mmol/mmol, P = .004). In GS patients with or without hyperuricemia, the impairment of NCC function indicated by the value of increase of chloride excretion fraction (△FECl) in the hydrochlorothiazide test was median 0.49% vs 0.82% (P = .10). We focused on the SLC12A3 genotype and 33 SNPs linked to uric acid levels and found no significant genetic differences between patients with or without hyperuricemia.

Conclusions: Hyperuricemia is common in patients with GS in China, associated with elevated BMI and potentially more severe NCC dysfunction.