Clinical and Experimental Nephrology最新文献

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.

Background: Debate continues regarding the potential of the ultrasonic renal length to serve as an indicator for evaluating the advancement of renal fibrosis in chronic kidney disease (CKD). This study investigates the independent association between renal length and renal fibrosis in non-diabetic CKD patients and assesses its diagnostic performance.

Methods: From April 2019 to December 2021, 144 non-diabetic patients diagnosed with CKD who underwent a renal ultrasound examination and kidney biopsy were prospectively enrolled. Patients were categorized into the mild fibrosis group (n = 70) and the moderate-severe group (n = 74) based on the extent of fibrotic involvement. Ultrasonic renal length was measured from pole-to-pole in the coronal plane. A receiver operating characteristic (ROC) curve, multivariable logistic regression analysis, and a generalized additive model were performed.

Results: A negative linear correlation was found between renal length and moderate-severe renal fibrosis risk. Each centimeter increase in renal length decreased the odds of moderate-severe fibrosis by 38% (OR: 0.62; 95% CI 0.41-0.93; P = 0.020). After adjusting for confounders, the relationship persisted (OR: 0.58; 95% CI 0.33-1.00; P = 0.048). However, renal length presented limited discrimination ability in distinguishing degrees of renal fibrosis while controlling the key confounding factors, yielding an area under the ROC curve of only 0.58 (95% CI 0.45-0.70).

Conclusion: While an inverse relationship exists between renal length and risk of having moderate-severe renal fibrosis in non-diabetic CKD patients, renal length alone is insufficient for diagnosing fibrosis severity, underscoring the need for additional diagnostic parameters in CKD assessment.

Background: Sodium-glucose cotransporter 2 (SGLT2) inhibitors have been shown in clinical trials to increase serum Mg²⁺ levels in patients with type 2 diabetes mellitus. However, it is unclear whether this effect is similarly observed in patients with chronic kidney disease (CKD) and whether such an increase is observed immediately after treatment.

Methods: Our retrospective observational study included the 62 patients with CKD who started SGLT2 inhibitor therapy at our institution between 2017 and 2022 and who had complete data on serum Mg²⁺ measurements at baseline and at 1, 3, and 6 months after treatment. Patients were divided into three subgroups, stratified by serum Mg²⁺ levels at baseline. We evaluated the changes in serum Mg²⁺ levels from baseline to 6 months after treatment and the factors associated with these changes.

Results: Median eGFR and mean serum Mg²⁺ at baseline were 33.5 mL/min/1.73 m² and 2.03 mg/dL, respectively. Treatment with SGLT2 inhibitors significantly increased serum Mg²⁺ levels immediately from 1 month after treatment compared with those at baseline and persisted over 6 months, with an overall mean change of 0.13 mg/dL from baseline to 6 months. This increased effect was observed in the low and middle tertile subgroups, but not in the high tertile subgroup. Multivariate linear regression analysis revealed that baseline serum Mg²⁺ levels and sodium-chloride differences, as a parameter of acid-base status, were independently associated with these changes.

Conclusions: SGLT2 inhibitors increased serum Mg²⁺ levels in patients with CKD, particularly those with lower baseline Mg²⁺ levels, potentially improving their prognosis.

Introduction: Clinical epidemiological data on monoclonal gammopathy of renal significance (MGRS) are lacking. In this retrospective observational study, MGRS was compared with B-cell or plasma cell malignancies (BCM/PCM) with renal involvement to clarify differences in their clinical features.

Methods: Among the 1408 renal biopsies performed at our hospital, 25 MGRS and 18 BCM/PCM patients were identified. We investigated baseline characteristics and hematologic parameters of MGRS in reference to BCM/PCM using multivariable analysis. Cox proportional hazards analysis was performed for end-stage kidney disease (ESKD) and all-cause mortality.

Results: Comparing the MGRS with the BCM/PCM, mean differences in creatinine level, estimated glomerular filtration rate, and clonal bone marrow plasma cell percentage were - 2.76 mg/dL, 27.72 mL/min/1.73 m², and - 18.86%, respectively (all P < 0.001). MGRS group had a predominance of glomerular lesions such as immunoglobulin-associated amyloidosis, cryoglobulinemic GN, and MIDD, and a lower risk of acute kidney injury/acute renal disease compared to BCM/PCM. During a median observation period of 23.7 months, clone-directed therapy was performed in 32.0% of patients in the MGRS group, compared to 83.3% of patients in the BCM/PCM group. Compared with BCM/PCM, MGRS had a hazard ratio of 0.66 (95% confidence interval (CI) 0.23-1.92, P = 0.45) for ESKD and 0.33 (95% CI 0.11-1.03, P = 0.06) for death in multivariate logistic regression analysis.

Conclusions: The clinical characteristics of MGRS and BCM/PCM with monoclonal immunoglobulin-associated renal disease are disparate. Understanding these differences is crucial for developing tailored clinical approaches and therapeutic strategies to improve patient outcome.