Clinical and Experimental Nephrology最新文献

Background: Previous reports highlighted the efficacy of hemofiltration utilizing isotonic sodium bicarbonate solution as replacement fluid for severe metabolic acidosis. This approach corrects metabolic acidosis by eliminating chloride and supplementing bicarbonate. Here, we present the results of an in vitro study aimed at determining the effect of Isotonic sodium bicarbonate-based Continuous HemoDiafiltration (IBB-CHDF).

Methods: Conventional Continuous HemoDiaFiltration (CHDF) and IBB-CHDF utilized aqueous solutions mimicking blood's electrolyte composition. To assess the efficacy and safety, we compared serial changes in pH, HCO₃^-, Na⁺, and K⁺ concentrations. Blood flow rate was 100 mL/min, and the dialysis fluid flow rate maintained 1.0 L/h for both CHDF and IBB-CHDF. Replacement flow rates ranged from 0.5 to 1.5 L/h for CHDF and 0.1 to 1.5 L/h for IBB-CHDF.

Results: At a replacement flow rate of 0.5 L/h with IBB-CHDF, bicarbonate increased from 14.7 mEq/L to within the physiological range (25.9 mEq/L), whereas in conventional CHDF, the post-treatment bicarbonate concentration did not increase (16.5 mEq/L). The maximum bicarbonate concentration achieved was 22.0 mEq/L at a replacement flow rate of 1.5 L/h in conventional CHDF. Notably, in IBB-CHDF, the sodium concentration remained constant at 150 mEq/L, 10 mEq/L higher than conventional CHDF, and did not escalate despite increasing the replacement flow rate.

Conclusion: IBB-CHDF effectively corrects metabolic acidosis without inducing sodium and water overload by eliminating excess chloride while providing bicarbonate.

Background: We investigated the roles of renal volumetry and histological features in the assessment of preoperative and postoperative renal function in living kidney donors (LKDs) including high-risk marginal donors (MDs).

Methods: We included 128 LKDs who underwent donor nephrectomy at our institution between 2006 and 2022. Clinical and radiographic data were retrospectively obtained from medical charts. Renal volume parameters were calculated using preoperative computed tomography images. Tissues obtained from allograft biopsies were examined. MDs were defined according to the Japanese guidelines and compared with standard donors (SDs).

Results: LKDs were divided into 89 SDs and 39 MDs. Renal volumetry parameters did not differ significantly between the two groups, while interstitial inflammation and interstitial fibrosis/tubular atrophy were significantly higher in MDs (P = 0.031 and P = 0.041). In the multivariate analysis, age < 60 years (P = 0.036), body mass index > 25 (P = 0.031), and residual kidney volume/body surface area (RKV/BSA; P = 0.002) were independent factors for poor preservation of renal function. Subgroup analysis of the MDs revealed that RKV/BSA (P = 0.0096), residual measured glomerular filtration rate (GFR) (P = 0.0005), and arteriosclerosis (P = 0.045) were associated with poor preservation of renal function. Furthermore, the risk of graft loss was significantly higher for kidneys donated from MDs (P = 0.0019).

Conclusions: RKV/BSA can be a reliable screening and prognostic tool for selection of LKDs, including MDs, and RKV/BSA, measured GFR, and histological findings such as arteriosclerosis can be used to establish clearer MD criteria for optimal personalized follow-up after surgery.

Backgrounds: Few studies have addressed the risk factors for the development of septic shock in older patients with urinary tract infections. We decided to investigate whether a similar risk exists in in older patients.

Methods: A total of 1478 older patients (492 men, 986 women) aged 65 years or older (mean age 85.1 years) who were hospitalized and treated for urinary tract infections were included in this study, and factors contributing to the development of septic shock in these patients, including in terms of the causative pathogens and treatments employed, were investigated through a retrospective review of the patients' medical charts.

Results: Underlying urinary tract infection with urolithiasis was found as the most significant risk factor for the development of septic shock (p < 0.01). Patients with urolithiasis were more frail, had higher urinary pH and calcium levels, and showed a higher frequency of infections caused by antimicrobial-resistant and rare bacteria. Cluster analysis revealed a higher incidence of death, septic shock, urolithiasis, and frailty in the patient group treated with carbapenem and/or MRSA agents.

Conclusion: Septic shock was associated with a high risk of death in older patients with urinary tract infections, and urolithiasis was identified as an independent risk factor for the development of septic shock. Urolithiasis was also associated with frailty, suggesting that prevention of frailty may indirectly improve the prognosis of patients with septic shock secondary to urinary tract infections.

Background: The objectives of this phase two study are to investigate the efficacy of two starting doses of 8.4 g and 16.8 g and evaluate the long-term safety of patiromer in Japanese patients with hyperkalemia.

Methods: This study comprised three cohorts; non-dialysis patients with baseline serum potassium (sK) level of 5.1 to < 6.0 mmol/L (NDC1); 6.0 to < 6.5 mmol/L (NDC2); dialysis patients with baseline sK level of 5.5 to < 6.5 mmol/L (DC). The study design was one-week, randomized, double-blind, placebo-controlled, and open label extension for one year in NDC1, open label during the study in NDC2 and DC. Patients were randomly assigned to patiromer 8.4 g, 16.8 g or placebo in NDC1, 8.4 g or 16.8 g in NDC2 and DC. Dose was adjusted up to 25.2 g according to the titration algorism in open label period.

Results: A total of 185 patients were randomized (NDC1:153, NDC2:10, and DC:22). The primary endpoint of the change in least squares mean sK levels at Week 1 in NDC1 was  - 0.55,  - 0.77 and  - 0.10 mmol/L for the 8.4 g, 16.8 g and placebo group (P < 0.001 for the patiromer group vs the placebo group). In all cohorts for each patiromer group, more than 80% of patients achieved normal sK at Week 5. There was no severe treatment-related adverse event.

Conclusion: Treatment with patiromer was effective in lowering and maintaining target sK levels, also well tolerated for one year in Japanese patients with hyperkalemia.

Background: The involvement of monoclonal immunoglobulin (MIg) in renal damage in patients with haematological disorders and renal biopsy-proven monoclonal gammopathy of renal significance is well established. However, no epidemiological studies have been conducted on the effects of MIg on renal function in other patients. We aimed to evaluate the renal prognosis of MIg-positive patients and the effects of MIg on renal function.

Methods: This retrospective observational study was performed using clinical data from all outpatients and inpatients who underwent MIg measurements at the time of enrolment at Kochi Medical School Hospital between 1 January 2017 and 31 December 2021. The primary outcomes were the occurrence of acute kidney injury (AKI) and a decline of > 30% in the estimated glomerular filtration rate (eGFR).

Results: Among the 1362 patients, 750 were included in our cohort. The number of MIg-positive and MIg-negative patients was 119 (15.9%) and 631 (84.1%), respectively. In addition, the MIg-positive patients were significantly older than the MIg-negative patients. The survival probability of the MIg-positive group was significantly lower than that of the MIg-negative group during the 2 year observation period. The risk factors for the primary endpoint were positive MIg, female sex, lower eGFR, and lower albumin level.

Conclusions: Our study showed that the presence of MIg was an independent risk factor for renal damage. Therefore, we suggest that MIg-positive patients require careful follow-up of their renal function, even in the absence of a clear underlying disease, such as multiple myeloma.

Background: Salt-sensitive hypertension (SSH) is the most severe form of hypertension, and the presence of NLRP3 inflammasome plays a crucial role in its pathogenesis. Although MCC950 has shown therapeutic potential for hypertension and kidney injury, its mechanism of action remains unclear.

Methods: Dahl salt-sensitive (SS) rats and their salt-tolerant aptamer control SS-13^BN (BN) rats were randomly assigned to four groups: SS rats intraperitoneally administered physiological saline (SS + vehicle) or MCC950 (SS + MCC950), and BN rats intraperitoneally administered physiological saline (BN + vehicle) or MCC950 (BN + MCC950). All rats were given 2% saline for drinking and received intraperitoneal injections of physiological saline or MCC950 (5 mg/kg) every other day. Biomarkers such as serum creatinine, urinary protein, sodium retention, NLRP3 inflammasome, inflammation, apoptosis, fibrosis, sodium channels and histopathological changes in kidney injury were evaluated in blood, urine, and kidney tissues.

Results: Compared with the SS + vehicle group, the SS + MCC950 group showed significantly lower blood pressure levels. Additionally, inhibition of NLRP3 inflammasome activation was observed along with reduced inflammation, apoptosis, fibrosis, and sodium retention in the kidneys.

Conclusions: The findings suggest that pharmacological inhibition of the NLRP3 inflammasome reduces blood pressure in SS rats and alleviates related kidney injury by suppressing inflammation, apoptosis, fibrosis, and sodium retention.

Background: Infection is a rare complication of percutaneous renal biopsy (RB). However, the questionnaire included in the Kidney Biopsy Guidebook 2020 in Japan revealed that antibiotic prophylaxis (AP) was administered at about 60% of hospitals. The objective of this study was to evaluate whether it is possible to omit AP for RB.

Methods: Patients aged ≥ 15 years were eligible. Three hundred and sixty-four patients were recruited at 6 hospitals. The patients were randomly assigned to receive either a single dose of intravenous cefazolin or no antibiotic prophylaxis. The primary outcome was the percentage of patients that exhibited positive urine cultures 3 or 4 days after the RB. The secondary outcomes were the percentage of patients who were diagnosed with pyelonephritis, puncture site infections (PSI), or an infection other than pyelonephritis or PSI within 30 days, and cefazolin-induced side effects.

Results: With regard to the primary outcome, there was no statistically significant difference between the cefazolin group and the no AP group (2.9% versus 5.1%, p = 0.416). With regard to the secondary outcomes, only one patient (who belonged to no AP group) developed pyelonephritis. This patient underwent urinary catheterization. No PSI occurred. There were no significant intergroup differences in any secondary outcomes.

Conclusion: This study revealed the incidence of post-percutaneous RB infections was minimal. Although the outcomes of this study did not lead to the conclusion that it is unnecessary to use AP for RB, the obtained data suggest that the effects of such AP may not be clinically significant.

Background: Cardio-renal syndrome, characterized by simultaneous cardiac and renal impairment, presents significant challenges in patient prognostication and management. This study aimed to investigate the C-reactive protein-to-albumin ratio (CRP/Albumin ratio) as a prognostic marker in patients with cardiorenal syndrome.

Methods: This observational cohort study included consecutive patients hospitalized for cardiorenal syndrome. Baseline demographics, medical history, and prior medication use were recorded. Routine laboratory tests, including serum CRP and albumin, were performed on the first hospitalization day, and their ratio was calculated. Patients were divided into two groups based on the median CRP/Albumin ratio. A transthoracic echocardiographic examination was conducted for each subject. The primary endpoint was in-hospital mortality.

Results: A total of 135 patients were enrolled (median age: 79 years, median hospitalization: 9 days, 64.5% male). The population was categorized into two groups: Group 1 with CRP/Albumin ratio < 576 and Group 2 with CRP/Albumin ratio ≥ 576. Baseline characteristics and medication use prior to admission were similar, except for a higher prevalence of diabetes and coronary artery disease in Group 2. Co-existing infection and oliguria/anuria were more common in Group 2. There were no significant differences in laboratory parameters and echocardiographic findings. Cox regression analysis revealed that a CRP/Albumin ratio ≥ 576 was an independent predictor of in-hospital mortality (hazard ratio: 3.09, 95% CI 1.22-7.81, p = 0.017), even after adjusting for confounders.

Conclusion: An elevated CRP/Albumin ratio was associated with a higher risk of in-hospital mortality in patients with cardiorenal syndrome, highlighting the critical role of inflammation in this population.

Background: The financial burden of kidney replacement therapy (KRT) is considerable, and detailed information on KRT costs is essential for managing these huge healthcare costs. However, cost analyses for kidney transplantation (KTx) are limited in Japan. This study aimed to report the healthcare costs of KTx recipients in Japan based on large medical receipt data.

Methods: This cost analysis of KTx recipients using the Japan Medical Data Center Claims Database between January 2005 and August 2020 identified living donor KTx (LDKT) and deceased donor KTx (DKT) recipients. The primary outcome was the total direct healthcare costs of KTx recipients. As an exploratory analysis, we examined the factors that contributed to the increase in the costs of LDKT.

Results: In total, 84 LDKT and 17 DKT recipients were included in this study. The total healthcare costs for LDKT and DKT recipients during the first year after KTx were 6,639,982 and 6,840,450 JPY/year, respectively. However, after the second year post-KTx, total healthcare costs decreased to 1,735,931 and 1,348,642 JPY/year for LDKT and DKT recipients, respectively. During the first year, inpatient costs accounted for > 70% of the total healthcare costs, whereas pharmaceutical costs accounted for more than half after the second year post-KTx. The use of everolimus and male sex were associated with higher and lower total healthcare costs in the first and subsequent years after LDKT, respectively.

Conclusion: Using large-scale administrative databases, this study revealed the total healthcare costs of KTx in Japan and provided valuable information for the health technology assessment of KTx.

We have achieved good results of renal transarterial embolization (TAE) therapy as an alternative to surgical nephrectomy to decrease renal size in autosomal polycystic kidney disease (ADPKD) patients with enlarged kidneys, but only in patients on dialysis. Renal transplantation is another treatment option, and patients who receive a donor kidney have achieved a reduction in kidney size after surgery. TAE has also been used in polycystic liver disease (PCLD), an extrarenal lesion of ADPKD. Although TAE is effective in some PCLD patients, others develop hepatomegaly, which leads to liver cyst infection and liver failure. Recently, liver transplantation has started to be performed in such patients. Initially, living donor liver transplants were performed from family members, but in 2010, deceased donor liver transplantation became available. This article gives an overview of the history of TAE for ADPKD and PCLD on the basis of our experience.