Clinical nephrology最新文献

Background: Patients with chronic kidney disease (CKD) have serum, bone, and vascular abnormalities presenting as chronic kidney disease-mineral bone disorder (CKD-MBD) syndrome. This study sought to identify the parameters with the greatest relative impact on progression of CKD-MBD abnormalities.

Materials and methods: This prospective study measured 237 parameters including serum markers, clinical variables, dual-energy X-ray absorptiometry (DXA) measurements, vascular calcifications, and histomorphometric results from bone samples obtained at baseline and after 2 - 3 years. Relative impact of these parameters on kidney function, bone changes, and vascular calcification were assessed using machine learning, a subset of artificial intelligence analyses.

Results: Baseline estimated glomerular filtration rate (eGFR) values ranged from 18 to 70 mL/min and declined in 52% of subjects by at least 3.3% annually during the study. These declines in eGFR were associated with changes in specific serum markers, bone quantity decreases, and bone quality alterations, but not with arterial calcifications. Arterial calcifications were associated with collagen crosslinking heterogeneity, serum phosphorus, diuretics and atorvastatin treatment, but not with kidney function. Baseline collagen crosslinking heterogeneity was an important factor impacting progression of coronary, but not aortic calcification. Baseline serum phosphorus was a factor primarily associated with progression of aortic calcification.

Conclusion: Machine learning revealed specific bone and vascular abnormalities occurring early during loss of kidney function. Bone, vascular, blood, medication use, and other parameters were identified impacting the presence and progression of arterial calcification and altering bone quality and quantity in this understudied patient population. Serum phosphorus levels considered normal impacted progression of arterial calcification. Identification of these parameters and their relative importance enhances our understanding of CKD progression and should improve patient care.

Acute kidney injury (AKI) is a frequent, severe complication of hematopoietic stem cell transplantation (HSCT) and is associated with an increased risk of morbidity and mortality. Recent advances in artificial intelligence (AI) and machine learning (ML) have showcased their proficiency in predicting AKI, projecting disease progression, and accurately identifying underlying etiologies. This review examines the central aspects of AKI post-HSCT, veno-occlusive disease (VOD) in HSCT recipients, discusses present-day applications of artificial intelligence in AKI, and introduces a proposed ML framework for the early detection of AKI risk.

Background: Acute kidney injury (AKI) is a common complication of critically ill COVID-19 patients which is associated with adverse outcomes. We examined clinical factors associated with hospital mortality in critically ill adult COVID-19 patients with AKI who required continuous renal replacement therapy (CRRT).

Materials and methods: We conducted a multicenter retrospective cohort study including data from two large academic medical centers. Adult (age ≥ 18 years) patients with AKI and requiring CRRT admitted from March 2020 to April 2021 were included in the study. Patients with end-stage kidney disease or renal transplantation were excluded. Multivariable Poisson regression analyses were used to identify clinical predictors of hospital mortality.

Results: A total of 178 patients were included. Patients were predominantly men (68.2%), 13.1% were Black, and 57.9% White. Median hospital and ICU length of stay were 20 days and 14 days, respectively. Mechanical ventilation and extracorporeal membrane oxygenation were utilized in 97.2% and 17.4% of patients, respectively. Overall, 130 (73.0%) patients died in the hospital (mortality rate of 2.7 per 100 person-days). In multivariable analyses, SOFA score ≥ 12 at ICU admission (MRRadj = 1.88; 95% CI 1.17 - 3.01) was associated with increased risk of mortality, while Black race (MRRadj = 0.56; 95% CI 0.31 - 1.01) was associated with a decreased risk of mortality.

Conclusion: More than two-thirds of critically ill adult COVID-19 patients with AKI requiring CRRT died during hospitalization. SOFA score ≥ 12 at ICU admission was an independent predictor of hospital mortality, and Black patients had a lower risk of mortality.

Introduction: Computed tomography peritoneography (CTp) is pivotal for evaluating peritoneal dialysis (PD)-related complications, yet it comes with drawbacks, specifically exposure to iodinated contrast media (ICM). This study aimed to explore the feasibility of reducing ICM dosage utilizing spectral detector CT (SDCT).

Materials and methods: 35 rabbits were strategically divided into 7 groups (A - G) according to the ICM concentration ratio in the injection protocol, with respective doses of 10, 15, 20, 25, 30, 40, and 50 mL/2L. The CTp injection protocol involved a 300-mL mixture of non-ionic ICM omnipaque (350 mgI/mL) and peritoneal dialysate (1.5% lactate, 2 L), followed by scans using dual-layer SDCT. Virtual monoenergetic images (VMIs) at 4 distinct energy levels (40 - 70 keV, in 10-keV steps), iodine maps (IMs), and effective atomic number (Zeff) maps were subsequently reconstructed. Both quantitative and qualitative image assessments were conducted, and the parameters from these analyses were compared across images from groups A - G and traditional 50 mL/2L 120-kVp images. In post-determination of the optimal concentration and reconstructions, we illustrated their applications in patients with suspected PD-related complications.

Results: The quantitative image quality (IQ) of 15 mL/2L VMIs at 40 keV surpassed that of the 50 mL/2L 120-kVp images (p < 0.05). Furthermore, the diagnostic performance utilizing 15 mL/2L VMIs40 keV, when combined with IMs and Zeff maps, was found to be optimal.

Conclusion: The employment of SDCT in CTp allows for a substantial reduction in the ICM dose by 70%, compared to the benchmark concentration of 50 mL/2L, without compromising diagnostic precision.

Background: Drug-induced kidney damage (DIKD) is a significant medical concern linked to many drugs, including nonsteroidal anti-inflammatory drugs, antibiotics, and chemotherapy agents, due to its complex pathophysiology. L-theanine, a tea leaf amino acid, is explored for its protective effects against DIKD, considering its cognitive and calming benefits.

Materials and methods: In the theoretical part of the article, the role of L-theanine in combating DIKD is reviewed, highlighting its ability to mitigate oxidative stress and inflammation by neutralizing reactive oxygen species, enhancing antioxidant defenses, and modulating anti-inflammatory pathways. L-theanine's influence on cell signaling and its synergy with other nephroprotective agents are discussed. The practical part describes an experimental study using a murine model, where 60 male C57BL/6 mice were divided into four groups: a control group, a nephrotoxic group treated with cisplatin, and two treatment groups that received L-theanine either before or after cisplatin administration. Serum biomarkers (creatinine and blood urea nitrogen (BUN)), histopathological kidney damage scores, and oxidative stress markers (malondialdehyde (MDA) and superoxide dismutase (SOD)) were measured.

Results: Evidence from the murine study indicates that L-theanine protects against DIKD through antioxidative, anti-inflammatory, and anti-apoptotic mechanisms, potentially enhancing its synergy with other nephroprotective agents. In the nephrotoxic group (N), serum creatinine and BUN levels were significantly elevated, while pre-treatment with L-theanine (LTP) reduced these levels to 1.2 ± 0.3 mg/dL and 34 ± 4 mg/dL, respectively. Histopathological analysis revealed severe tubular necrosis in the N group (score: 3.8 ± 0.3), which was significantly reduced in the LTP group (1.6 ± 0.4). Oxidative stress markers, such as MDA, were markedly lowered in the LTP group compared to the N group, with corresponding increases in SOD activity, indicating enhanced antioxidant defense. These findings underscore L-theanine's potential in preserving renal health amidst pharmacotherapy-induced toxicity.

Conclusion: L-theanine emerges as a promising nephroprotective agent, particularly in the context of increasing incidence of DIKD and the associated challenges in clinical management. The practical findings from this study in a murine model provide compelling evidence that L-theanine significantly reduces serum biomarkers of renal injury, attenuates tubular necrosis, and mitigates oxidative stress, with pronounced effects observed when administered as a pre-treatment. While these results are promising, the predominance of preclinical data underscores the need for rigorous human studies to validate L-theanine's efficacy and safety in the prevention of drug-related renal injuries. Such research is crucial for advancing renal protection strate

Introduction: Brown tumors are benign lesions caused by hyperparathyroidism and characterized by increased osteoclast activity and mass effect, which can lead to paraplegia when the spine is involved. Secondary hyperparathyroidism is common in patients on long-term hemodialysis therapy.

Case report: We report the case of a 48-year-old man on regular dialysis who presented with leg weakness as well as back pain and was diagnosed with secondary hyperparathyroidism and thoracic spine tumor. Since the spinal cord was compressed, T12 mass excision combined with spinal canal decompression was performed under general anesthesia. Post-operative pathology demonstrated abundant fibrovascular tissue and osteoclast-like multinucleated giant cells with hemorrhage and hemosiderin pigment deposition. The patient was diagnosed with brown tumor. Following operation, the patient recovered well. He remains on regular hemodialysis with follow-ups and unaffected activities 10 years later.

Discussion: In dialysis patients with combined spinal tumors, brown tumors should be considered. For patients presenting with symptoms of spinal cord compression, surgical resection can lead to a favorable prognosis.

Objective: Antineutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV), a multisystem autoimmune disorder, deteriorates small vessels. Kidney involvement occurs in most affected patients and is the most common cause of rapidly progressive glomerulonephritis (RPGN). Rituximab (RTX), an anti-CD20 antibody, has been used in the induction and maintenance therapy of AAV as a non-inferior alternative to cyclophosphamide. Administration of 4 once-weekly doses of 375 mg/m² is the common dose in remission induction therapy, referred to as a conventional regimen. Recently, it was shown that the cumulative complete remission (CR) rates did not differ between low-dose RTX (2 once-weekly doses of 375 mg/m²) and the conventional RTX regimen. We aimed to explore the effect of the B cell-driven RTX dosing regimen.

Case reports: Herein, we reported B cell-driven reduced-dose RTX therapies in a 71-year-old male de novo patient (case 1) and a 60-year-old female patient (case 2). Case 1, de novo diagnosed based on kidney biopsy, received 3 once-semimonthly doses of 300 mg RTX as induction therapy. Case 2, who was clinically diagnosed with ANCA-associated renal vasculitis 4 years before receiving treatment at our hospital, accepted 4 once-monthly doses of 300 mg RTX as induction therapy. Further dosages were dependent on peripheral CD19+ B-cell levels.

Results: During the course of treatment, peripheral B-cell counts of both patients turned 0, and symptoms of both patients improved, complete remission occurred in case 1, with a Birmingham vasculitis activity score (BVAS) of 0.

Conclusion: B cell-driven reduced-dose RTX might be also effective in induction therapy for AAV. Further study is warranted to confirm the efficacy, safety, and risk of relapse of a reduced-dose RTX regimen.

Background: Among hemodialysis patients, left ventricular hypertrophy (LVH) is a prevalent cardiac abnormality. The uremic toxin indole-3-acetic acid (IAA) is elevated in uremia patients, but the connection between IAA and LVH in individuals undergoing hemodialysis remains uncertain. Hence, the objective of this research was to examine the correlation between blood IAA levels and LVH in individuals undergoing hemodialysis.

Materials and methods: In total, 205 individuals undergoing hemodialysis were chosen and categorized into two groups, with (143 patients) and without LVH (62 patients). Patient clinical data were collected, and serum creatinine, calcium, phosphorus, hemoglobin, and IAA levels were measured.

Results: Compared to the non-LVH group, the LVH group had higher IAA and serum phosphorus but lower hemoglobin. The serum IAA concentration was positively correlated with both left ventricular mass (LVM) and left ventricular mass index (LVMI) but negatively correlated with both left ventricular ejection fraction (LVEF) and the ratio of left ventricular transmitral early peak flow velocity to left ventricular transmitral late peak flow velocity (E/A). Logistic regression analysis indicated that increased IAA levels are a risk factor for LVH and are not influenced by other factors. In addition, we exposed primary neonatal cultured mouse cardiomyocytes to varying concentrations of IAA in a controlled environment. Cardiomyocyte hypertrophy was induced by IAA in a concentration-dependent manner.

Conclusion: Serum IAA is correlated with alterations in both the function and structure of the left ventricle. The serum IAA concentration is an independent risk factor for LVH. IAA may be a novel biomarker of LVH in hemodialysis patients.

Introduction: Kidney dysfunction is a frequent complication of multiple myeloma (MM) and is associated with worse survival outcomes. Despite its prevalence, the prognostic value of long-term kidney function decline remains insufficiently explored. This study aimed to investigate the impact of the estimated glomerular filtration rate (eGFR) slope on survival in patients with MM.

Materials and methods: A retrospective cohort study was conducted on 43 patients with MM treated at the University Medical Center Maribor between 2015 and 2020, with a minimum follow-up of 1 year. Kidney function was assessed quarterly using eGFR. Kaplan-Meier analysis and Cox regression were applied to evaluate the association between eGFR slope and overall survival.

Results: The median baseline eGFR was 52.8 mL/min/1.73m² (interquartile range: 35.2 - 78.1), with 39.5% of patients classified as having stage 3 or worse chronic kidney disease. We observed an association between faster annual eGFR slope decline and increased mortality (log-rank; p < 0.001). Cox regression confirmed eGFR slope as an independent predictor of mortality (hazard ratio = 1.121, 95% confidence interval: 1.069 - 1.174, p < 0.001). Additional prognostic factors included a lower platelet count.

Conclusion: Kidney function decline is an independent prognostic factor in patients with MM. Regular monitoring and early nephrology intervention may help mitigate its impact. Future research should focus on targeted strategies to slow kidney function deterioration and improve patient outcomes.

Rituximab (RTX) is the anti-CD20 monoclonal antibody that has been used as the first-line therapy for primary membranous nephropathy (PMN) in recent years. However, the optimal dosing regimen and timing of RTX, or combination with other immunosuppressants, especially in patients with extremely high titers (> 1,000 RU/mL) of anti-PLA2R antibody (aPLA2R), are unclear at present. This report describes the case of a 70-year-old PMN patient with extremely high aPLA2R titer who failed to respond to very high doses of RTX. We also discuss the possible reasons for treatment failure.