Clinical and Experimental Nephrology最新文献

Background: Exercise is recommended to prevent dialysis; however, the involvement of physical therapists is not a criterion for reimbursable medical fee calculation in Japan. Consequently, eligible patients may not receive appropriate exercise guidance. We aimed to clarify the extent of physical therapist participation in dialysis-prevention interventions reimbursed under the current Japanese healthcare system and to identify reasons for non-participation related to reimbursement criteria.

Methods: In January 2025, a 30-item questionnaire was distributed to all facility representatives registered with the Japan Physical Therapist Association to investigate medical fees and physical therapist involvement in dialysis prevention. Dialysis-prevention interventions were defined as those reimbursed under the Japanese healthcare system: Lifestyle-Related Disease Management, Diabetes Dialysis Prevention Guidance and Management (including Guidance of Patients with Severe Renal Impairment), and Chronic Kidney Disease (CKD) Dialysis Prevention Guidance and Management.

Results: Of the 10,285 facilities surveyed, 1322 (12.9%) responded. Among these, physical therapists participated in Lifestyle-Related Disease Management, Diabetes Dialysis Prevention Guidance and Management, and CKD Dialysis Prevention Guidance and Management in 4.8%, 3.5%, and 2.3% of facilities, respectively. The most frequently cited reasons for exclusion were "Inclusion of physical therapists is not a strict requirement for medical fee reimbursement," "Insufficient personnel or time," and "No role assigned by the dialysis-prevention team."

Conclusion: Physical therapist involvement in dialysis-prevention interventions was limited, primarily due to current medical fee reimbursement criteria. Revising the healthcare system to facilitate their inclusion may enhance the delivery of exercise-based preventive care.

Background: Comprehensive epidemiological information regarding Alport syndrome, particularly from national cohorts, is limited.

Methods: Utilizing a national Alport syndrome cohort in Japan established in October 2022, we analyzed clinical characteristics according to genotype. Only baseline data collected retrospectively at enrollment were used. We present longitudinal trends in estimated glomerular filtration rate (eGFR) and urine protein-to-creatinine ratio.

Results: Of the 121 patients included, 105 (86.8%) underwent genetic testing and 82 (67.8%) had a kidney biopsy. Among those with genetic testing, 77 (73.3%) had X-linked Alport syndrome. Kidney function was normal at disease onset, with a median eGFR of 112.9 (interquartile range, 99.3-131.1) mL/min/1.73 m². Although a steep decline during adolescence was observed in some male patients with X-linked Alport syndrome, eGFR decline was relatively slow during childhood and adolescence; the point estimate of eGFR at age 20 was 88.6 mL/min/1.73 m². Six patients transitioned to end-stage kidney disease during the follow-up period. Eighty-one patients (66.9%) used renin-angiotensin system (RAS) inhibitors, and the rate of eGFR decline was slower after RAS inhibitor initiation. Notably, the median ages at onset and diagnosis were 3.0 and 5.1 years, respectively, because Japan's widespread urinalysis screening program for 3-year-old children enables initiation of early treatment.

Conclusions: In our cohort, which consisted mainly of patients who did not require kidney replacement therapy in childhood and adolescence, kidney function was preserved throughout this period except for some male patients with X-linked Alport syndrome. RAS inhibitor use may be associated with a reduced rate of eGFR decline.

Background: Nephrotic syndrome (NS) carries a high risk of severe complications and kidney failure, necessitating reliable prognostic markers. Given the link between tubular injury and poor remission of proteinuria, markers of tubular function may be informative in NS. The urine-to-blood urea nitrogen ratio (UBUR) reflects tubular urea handling, yet its prognostic value in NS is unclear. We evaluated whether baseline UBUR predicts proteinuria remission in adult NS.

Methods: This multicenter retrospective study included patients with NS who underwent kidney biopsy between January 2012 and June 2022. Patients were followed from kidney biopsy until complete remission, dialysis initiation, death, or the end of the observation period (12 months after kidney biopsy).

Results: A total of 237 patients (median age, 63 years; 47% female) were included, and divided into two groups based on a UBUR cutoff of 25.4 determined by the receiver operating characteristic curve. Patients with high UBUR had a significantly higher cumulative incidence of complete remission compared to those with low UBUR (P < 0.001, log-rank test). In multivariable Cox regression analysis, high UBUR independently predicted a greater likelihood of complete remission (hazard ratio 2.30 [95% confidence interval 1.47-3.61]). This association persisted in the subgroup analyses for podocytopathies, defined as minimal change disease and focal segmental glomerulosclerosis.

Conclusions: High UBUR independently predicts proteinuria remission in adults with NS. UBUR could have potential as a simple, valuable biomarker to help guide the management of NS.

Background: Catheter exit-site infection is a major cause of withdrawal from peritoneal dialysis (PD). However, methods for caring for the peritoneal catheter and exit sites are not established and vary among facilities. No survey has been conducted on exit-site management in Japan. Here, we aimed to identify successful examples that led to best practices.

Methods: The Japanese Society for Peritoneal Dialysis-led PD-related infection project was launched in 2023, under which a survey was conducted at 14 facilities nationwide that provide PD therapy. The survey content included questions about the timing of the initiation of exit-site care, the materials used in exit-site protection, and the disinfectants used for exit-site care.

Results: Seventy-one percent of the exit-site direction was downward. In all facilities, the exit site was dressed immediately after its creation for several days up to a certain period. Many facilities started exit-site care within 1-2 weeks of PD initiation. Notably, 50% of the facilities did not use disinfectants. Twelve facilities used gauze or film dressings to protect the exit site. The catheter was secured in many facilities; however, the distance of fixation varied. The timing for starting a shower after exit-site creation was commonly 1-4 weeks post-surgery. Nine facilities allowed bathing without a cover, typically after > 1 month. Of these, 7 did not use Spa Clean.

Conclusions: These findings provide insights into exit-site care trends across facilities. Further studies and trials are needed to establish the best practice on exit-site care for Japanese patients undergoing PD.

Purpose: To investigate the safety and effectiveness of transcatheter arterial embolization (TAE) with tris-acryl gelatin microspheres in patients with symptomatic enlarged polycystic kidneys (PCKs).

Material and methods: This prospective study was planned as a safety trial for patients with symptomatic enlarged PCKs who complained of a marked abdominal distention, gastroesophageal reflux, or abdominal pain. We then assessed renal volume reduction and improvement in clinical symptoms as secondary endpoints. The patients after induction of dialysis therapy (urinary volume less than 500 mL per day) were included. Bilateral renal TAE with tris-acryl gelatin microspheres injection followed by metallic coils placement was performed, and adverse events, clinical symptoms, abdominal circumference, blood pressure, dry weight and laboratory data were evaluated at 1, 3, 6 and 12 months after TAE. Each kidney volume was calculated before TAE and at 3, 6 and 12 months after TAE.

Results: Six kidneys of three patients (65-, 58- and 54 years women) were treated. All three patients experienced abdominal pain, vomiting and inflammatory reactions immediately after TAE; however, abdominal pain and vomiting resolved within their hospitalization period, and inflammatory reactions improved during the follow-up period in all patients. Accelerated renal anemia was ameliorated by temporary blood transfusions and increased doses of erythropoiesis-stimulating agent or darbepoetin alpha during dialysis. The mean kidney volume was 3885 mL before TAE and 3025, 2320 and 1832 mL at 3, 6 and 12 months after TAE, respectively.

Conclusion: Renal TAE with tris-acryl gelatin microspheres is considered a safe and effective treatment for symptomatic enlarged PCKs.

Trial registration: This clinical trial was registered with the University Hospital Medical Information Network (UMIN) under the registration number UMIN000016576.

Background: Acute kidney injury (AKI) caused by red yeast rice Cholestehelp® (CP) tablets has become a public health issue in Japan. Puberulic acid (PA) contaminated in CP tablets may cause AKI; however, we detected silica nanoparticles in a CP patient. CP-related kidney injury was examined in rats that underwent left nephrectomy to increase silica nanoparticle loading.

Methods: Six male Sprague-Dawley rats were administered CP and underwent left nephrectomy on day 4. Blood and urine samples were collected on day 11. Renal tissues were observed by electron microscopy and low-vacuum scanning electron microscopy-energy dispersive X-ray spectroscopy (LVSEM-EDS). The amount of PA in CP was measured, and PA was administered to normal rats and unilaterally nephrectomized rats.

Results: Normal rats receiving CP (2KCP) had increased urine volume and lower urine specific gravity than controls, but no significant changes were observed in urinary protein, renal function, electrolytes, or blood gasses. Unilaterally nephrectomized rats receiving CP (1KCP) had increased water intake and urine volume, decreased urine specific gravity, and increased low-molecular-weight proteinuria. The glomeruli of 1KCP rats showed expanded subendothelial space and increased endocytic vesicles were observed in the proximal tubules relative to 2KCP rats. The accumulation of nanoparticles in the endosomes of the proximal tubules, and LVSEM-EDS detected silicon in renal tissue. Administration of PA at the doses in CP tablet did not result in significant renal injury.

Conclusions: Uninephrectomized rats administered CP tablets showed accumulation of silicon-containing nanoparticles in the proximal tubules and renal injury.

Background: The trajectory of the ankle-brachial index (ABI) over time in relation to death has not been fully described in patients undergoing hemodialysis. We modeled ABI trajectory pattern before death in patients undergoing maintenance hemodialysis.

Methods: Patients undergoing hemodialysis in a dialysis facility were retrospectively enrolled and categorized into two groups, deceased and surviving groups, based on their status at the end of the observation period. Linear mixed-effect model and a backward timescale from the year of death or study end date were used to compare ABI trajectory between the deceased and surviving groups during the observation period.

Results: A total of 442 patients (median age, 65 years; 60.2%, men) were included. During the observation period (median, 5.3 years; maximum, 8.5 years), 130 deaths were observed. Differences in ABI between the deceased and survivors were detected in the early stages (difference at 7 years before death, 0.08; p = 0.01), with the differences between these groups becoming more pronounced at 1 year before death (difference at 1 year before death, 0.11; p < 0.001).

Conclusions: Differences in ABI trajectory between the deceased and survivors were detected from the early stages to just before death.

Renal ischemia-reperfusion injury (RIRI) is a major cause of acute kidney failure. Recent studies have shown that RIRI mechanism is closely related to abnormal mitochondrial biogenesis, fusion, fission, and autophagy. Maintaining normal mitochondrial function is essential for RIRI treatment. Therefore, it is important to explore molecular mechanisms of RIRI and relevant therapeutic targets. This review describes the role of mitochondria in RIRI and summarises information about potential drugs that regulate mitochondrial function, with the aim of providing ideas for clinical targeting of mitochondria to prevent and treat RIRI.