Nephron最新文献

Introduction: Arteriolar hyalinosis (AH) has been shown to be associated with albuminuria and GFR. In this study, we investigated whether or not index of AH (IAH) is a predictor of the onset of macroalbuminuria and impaired renal function (eGFR <60 mL/min/1.73 m2 [eGFR <60]) in type 2 diabetic patients with early diabetic nephropathy.

Methods: The study population consisted of 35 patients with type 2 diabetes (25 men; age: 47 ± 9 years; eGFR: 92.7 ± 18.0 mL/min/1.73 m2) with normo- or microalbuminuria who underwent percutaneous renal biopsy. These patients were followed for at least 5 (18 ± 6, range: 6-28) years. The study endpoint was the onset of macroalbuminuria or eGFR <60. Light and electron microscopy-based morphometric analyses were performed to quantitatively evaluate glomerular and interstitial structural changes.

Results: During the observation period, 9 out of the 35 patients progressed to macroalbuminuria, and 15 out of the 35 patients developed eGFR <60. The annual rate of eGFR decline was significantly correlated with IAH (r = -0.40, p = 0.016). Kaplan-Meier analysis demonstrated that AH was associated with a significantly higher risk of onset of macroalbuminuria and eGFR <60, and microalbuminuria is associated with the onset of macroalbuminuria but not the onset of eGFR <60.

Conclusions: Aggravated AH is a histological risk factor which predicts the onset of macroalbuminuria and eGFR <60 in patients with type 2 diabetes. These findings provide novel insights into the mechanism of progression of diabetic nephropathy.

Background: Renal anemia is one of the most common complications of chronic kidney disease (CKD). This real-life study assessed the effectiveness of methoxy polyethylene glycol-epoetin beta, a continuous erythropoietin receptor activator (C.E.R.A.), for the treatment of CKD-associated anemia in patients receiving dialysis in daily clinical practice.

Methods: 247 patients receiving chronic intermitted dialysis in 26 centers in Poland with CKD-associated symptomatic anemia, ESA-naïve, and with balanced iron stores in the investigators' opinion were enrolled this real-life study. Over 12 months, the following data were collected: hemoglobin (Hb) concentration and dosage, route of administration and dosing scheme of C.E.R.A., dialysis adequacy, adverse events, iron therapy, and blood transfusions.

Results: During the treatment, a Hb concentration of ≥10 g/dL was noted in 90.9% of hemodialysis patients (n = 224) and 96.0% of peritoneal dialysis patients (n = 23). At baseline, 7.8% of patients had a Hb concentration of 10-12 g/dL, which increased to 63.3% after 12 months. The median time when Hb concentration was maintained within 10-12 g/dL was 115.2 (interquartile range 49.1-188.7) days. A Hb concentration ≥12 g/dL was observed after 7 months of treatment in a maximum of 24.1% of hemodialysis patients, and 31.8% of peritoneal dialysis patients. The median time elapsed between the start of treatment and the first Hb concentration >10 g/dL was 42.0 (21.0-78.2) days. C.E.R.A. was well tolerated.

Conclusions: C.E.R.A. corrects CKD-associated anemia in dialysis patients, and maintains Hb levels within the recommended target range. The study also confirmed the acceptable safety profile of the drug.

Background: Equations based on serum creatinine (SCr) have been extensively applied to estimate glomerular filtration rate (GFR), but their performance is debatable. In 2021, the European Kidney Function Consortium (EKFC) published one novel SCr-based formula, which combined the feature of Chronic Kidney Disease Epidemiology Collaboration (CKD-EPI) and full age spectrum (FAS) equations, but its potential applications remain unknown. We seek to assess the appropriateness of the three equations in Chinese adults.

Methods: A total of 3,692 participants (median age, 54 years) were included. Reference GFR (rGFR) was measured by the 99mTc-DTPA renal dynamic imaging method. Estimated GFR (eGFR) was calculated by the CKD-EPI, FAS, and EKFC equations. Correlation coefficients and Bland-Altman analysis were adopted to evaluate their validity. The performance was assessed in subgroups according to age, sex, rGFR, and SCr, considering the bias, accuracy, and precision.

Results: The average rGFR was 74.2 mL/min/1.73 m2. eGFR by EKFC showed a relatively stronger correlation with rGFR (R = 0.749) and a larger area under the receiver operating characteristic curve (0.902). EKFC was significantly less biased and exhibited the highest P30 in the entire population (bias = 3.61, P30 = 73.3%). It also performed well in all analyzed subgroups, especially in participants with normal or slightly impaired renal function (rGFR≥60 mL/min/1.73 m2), and low SCr.

Conclusions: Compared to the other two SCr-based formulas, EKFC performed better in the Chinese. Thus, it might serve as a good alternative, until a more suitable formula is developed for the Chinese population.

Background: Although most patients with atypical hemolytic uremic syndrome (aHUS) have variants in genes participating in alternative complement pathways, rare variants in non-complement pathway-related genes, including DGKE, INF2, MMACHC, PLG, and THBD, have also been described.

Case presentation: We report an 18-year-old male patient with renal biopsy-proven chronic thrombotic microangiopathy that raised suspicion of aHUS. Whole-exome sequencing revealed a novel pathogenic homozygous MMACHC c.484G>T (p.Gly162Trp) variant. Subsequently, clinical and laboratory findings confirmed cobalamin C (Cbl C) deficiency. Also, homozygous missense c.1112C>T PLG (p.Thr371Ile) variant was detected (it had been reported as a variant of unknown significance). However, the low serum plasminogen (PLG) activity proved the pathogenicity of c.1112C>T. Hence, the patient was diagnosed with concurrent Cbl C and PLG deficiencies. Segregation analysis revealed that the mother and father had the same heterozygous PLG and MMACHC variants. PLG variants have generally been described in aHUS patients concomitant with complement gene variants in the literature; therefore, the association between aHUS and PLG variants is controversial. The possible contribution of PLG deficiency to thrombotic microangiopathy was also discussed in this case.

Conclusion: Non-complement-mediated aHUS is an exceptional disorder. A limited number of genes are involved in this entity. To our knowledge, this is the first aHUS patient diagnosed with both Cbl C and PLG deficiencies in the literature.

Background: Living kidney donors (LKD) may experience some untoward consequences following donation such as development of chronic kidney disease (CKD). In this study, we aimed to investigate the rate of development of CKD and factors affecting the development of CKD in LKDs during long-term follow-up from a center in Turkey.

Methods: This study was a retrospective analysis of LKDs followed between January 2000 and December 2017. Pre-transplant and post-transplant clinical data of the 338 LKDs were recorded and compared. Factors affecting the development of stage 3 and later stages of CKD were analyzed.

Results: Majority of the donors were females (64.2%), and the median age of all donors was 47 (39-54) years. Stage 3 CKD developed in 50 donors during the median follow-up of 71 months. Older age at the time of transplantation and a low pre-transplant estimated glomerular filtration rate (eGFR) were determined as the factors affecting the development of stage 3 CKD (p < 0.001, p < 0.001). The receiver operating characteristic analysis showed that the cut-off age for the development of stage 3 CKD was 50.5 years. Newly diagnosed hypertension was detected in 57 patients (16.8%) after the transplantation. While hypertension was seen at a rate of 42% in those with an eGFR <60 mL/min/1.73 m2, it was detected at 19.4% in the group with an eGFR >60 mL/min/1.73 m2 (p < 0.001).

Conclusion: These results reveal that being a LKD is associated with the development of CKD and hypertension. Age and eGFR values at the time of transplantation were the determinants for the development of CKD.

Introduction: Membranoproliferative glomerulonephritis is currently divided into immunoglobulin-mediated glomerulonephritis (IC-MPGN) and C3 glomerulopathy (C3G); however, the patients often overlap with histology, complement, clinical and prognostic factors. Our aim was to investigate if an unsupervised clustering method finds different patient groups in 44 IC-MPGN/C3G patients using only histological and clinical data available in everyday clinical work.

Methods: Primary IC-MPGN/C3G adult patients were included whose diagnostic (baseline) native biopsy was obtained in 2006-2017. The biopsies were reassessed and the clinical data at baseline and during follow-up were obtained from the medical records. There were 39 baseline histological and clinical variables included in the unsupervised clustering. Follow-up information was combined with the clustering results.

Results: The clustering resulted in two clusters (n = 24 and n = 20 patients for clusters 1-2, respectively), where cluster 1 had a significantly higher baseline plasma creatinine (mean 213 vs. 104, respectively, p value <0.001) and a lower baseline eGFR than cluster 2 (mean 37 vs. 70, respectively, p value <0.001). Regarding histology, chronic changes such as lobulated glomeruli, mesangial matrix expansion, and glomeruli double contours were more prevalent in cluster 1 (p value <0.001). Biopsy morphology was more often crescentic and membranoproliferative in cluster 1 (p value <0.001). Although the differences were insignificant, cluster 1 patients were in dialysis in the last follow-up or had a progressive disease more often than cluster 2 patients (21% vs. 5%, 38% vs. 10%).

Conclusions: Our results indicate that these patients share greater similarity than the current classification IC-MPGN versus C3G indicates.

Introduction: The first version of Animal Research: Reporting of in vivo Experiments (ARRIVE 1.0) guidelines was introduced to improve reporting of animal research but did not lead to major improvements in this respect. This applied also to animal studies on peritoneal dialysis (PD). Here, we examined the performance of the revised version of these guidelines (ARRIVE 2.0).

Methods: Eighty-nine relevant articles published in 2018-2020 (ARRIVE 1.0 period) and 97 published in 2021-2023 (ARRIVE 2.0 period) were identified in PubMed® and analyzed for completeness and transparency of reporting.

Results: In both periods, most studies were carried out in Asia, on rodents, and concerned the peritoneal pathophysiology. During ARRIVE 2.0, more studies were published in higher impact factor journals with the focus on pharmacology and immunology. Compared to ARRIVE 1.0, general aspects of study design and reporting improved during ARRIVE 2.0 period in studies generated in Europe and USA but did not change significantly in Asia. Detailed analysis showed no global improvement in completeness of reporting key information included in the ARRIVE 2.0 Essential 10 checklist. Articles from both periods were deficient in sample size calculations, use of blinding, recording adverse events and drop-outs, and specification of appropriate statistical methods. The level of reporting during ARRIVE 2.0 did not correspond to the journal impact factor and the presence of recommendations for the use of ARRIVE 2.0 in their instructions to authors.

Conclusion: So far, ARRIVE 2.0 has not produced significant improvements in the reporting of animal studies in PD.

Background: Beta cells play a key role in the pathophysiology of diabetes since their functional adaptation is able to maintain euglycemia in the face of insulin resistance, and beta cell decompensation or dysfunction is a necessary condition for full-blown type 2 diabetes (T2D). The mechanisms behind compensation and decompensation are incompletely understood, especially for human beta cells, and even less is known about influences of chronic kidney disease (CKD) or immunosupressive therapy after transplantation on these processes and the development of posttransplant diabetes.

Summary: During compensation, beta cell sensitivity to glucose becomes left-shifted, i.e., their sensitivity to stimulation increases, and this is accompanied by enhanced signals along the stimulus-secretion coupling cascade from membrane depolarization to intracellular calcium and the most distal insulin secretion dynamics. There is currently no clear evidence regarding changes in intercellular coupling during this stage of disease progression. During decompensation, intracellular stimulus-secretion coupling remains enhanced to some extent at low or basal glucose concentrations but seems to become unable to generate effective signals to stimulate insulin secretion at high or otherwise stimulatory glucose concentrations. Additionally, intercellular coupling becomes disrupted, lowering the number of cells that contribute to secretion. During progression of CKD, beta cells also seem to drift from a compensatory left-shift to failure, and immunosupressants can further impair beta cell function following kidney transplantation.

Key messages: Beta cell stimulus-secretion coupling is enhanced in compensated insulin resistance. With worsening insulin resistance, both intra- and intercellular coupling become disrupted. CKD can progressively disrupt beta cell function, but further studies are needed, especially regarding changes in intercellular coupling.

Introduction: Chronic kidney disease (CKD) affects people across their lifespan. Kidney supportive care (KSC) is typically offered for older people for symptom management, education, and/or advance care planning (ACP). However, younger people may also benefit from KSC. This study sought to explore characteristics of working-age adults with CKD accessing KSC.

Methods: Using a cross-sectional design, working-age adults (18-64 years) with CKD referred to a KSC service from February 2016 to July 2021 were included. Demographic and clinical data were extracted from patients' hospital records. Self-reported symptoms (Integrated Palliative Care Outcome Scale renal [IPOS-renal]) and health-related quality of life (European quality of life [EQ-5D-5L]) were assessed. Reasons for referral to KSC, kidney replacement therapy (KRT) pathway at referral, and comorbidity calculated using the Charlson Comorbidity Index were also assessed.

Results: One Hundred Fifty-six working-age adults attended the KSC service. Median age was 57 years, with more than half receiving KRT. Weakness (92.2%), poor mobility (83.3%), and pain (82.5%) were the most prevalent and severe symptoms. The majority were referred for symptom management (n = 83, 53.2%) and 27% for ACP (n = 42). The ACP completion rate was low (28.9%). Those on dialysis had significantly higher symptom scores than those not receiving dialysis (p < 0.05).

Conclusion: Working-age adults with CKD experience a significant and debilitating symptom burden and need to consider options for treatment. This study provides new understanding about working-age adults with CKD that may help provide the specific support needed to meet their end-of-life care needs.

Introduction: Kidney biopsy is the cornerstone for the diagnosis of glomerular diseases and to guide treatment. Percutaneous ultrasound-guided kidney biopsy is currently the gold standard to obtain cortical specimens. However, in cases where ultrasound-guided kidney biopsy is not deemed safe (obese patients, deep kidneys, or kidneys with a complicated anatomy), CT-guided kidney biopsy could be a convenient alternative to obtain renal tissue samples. The aim of this study was to describe the diagnostic yield and complications of CT-guided kidney biopsies in patients with glomerular diseases that were previously discarded for ultrasound-guided kidney biopsy.

Material and methods: We performed a retrospective, single-center, observational study including patients who underwent CT-guided native kidney biopsies in our center after being contraindicated for ultrasound-guided biopsy. Patients' records were reviewed retrieving baseline characteristics and pre-biopsy clinical, laboratory parameters and concomitant medication. The biopsy needle gauge, site of puncture, and number of needle passes were recorded. The diagnostic yield was evaluated by the number of glomeruli obtained, the rate of specimens that were adequate to reach diagnosis, and the number of biopsies that had to be repeated. Complications were defined as minor (hypotension, hematoma) and major (arteriovenous fistulae, major bleeding requiring embolization, or nephrectomy). The diagnostic yield and complications were compared to ultrasound-guided native kidney biopsies performed during the same period.

Results: 56 CT-guided native kidney biopsies were performed during the study period. The number of glomeruli obtained per patient was 11.5 ± 6.3, which was inferior to that obtained from ultrasound-guided biopsies (14.08 ± 8.47, p < 0.05). However, the rate of specimens that were adequate to reach a diagnosis was similar (92.9% vs. 90.8%, p = 0.437). The number of needle passes was higher in CT-guided kidney biopsies (2.0 ± 0.7 vs. 1.7 ± 0.5, p < 0.05), as well as the incidence of post-biopsy perirenal asymptomatic hematomas (66.1% vs. 24.5%, p < 0.01). There were no significant differences in other post-biopsy minor complications (1.8% vs. 2.5%, p = 0.621). There were no major complications after CT-guided kidney biopsies.

Conclusions: CT-guided percutaneous kidney biopsy is a valid alternative for the diagnosis of glomerular diseases in patients with special characteristics such as obesity or deep kidneys that contraindicate ultrasound-guided biopsy. In this population, CT-guided kidney biopsies are safe and provide a high diagnostic yield, reaching a diagnosis in >90% of patients that had been previously discarded for ultrasound-guided biopsy.