Objective To compare the safety and efficacy of calcium-containing replacement fluid and calcium-free replacement fluid in an citrate anticoagulation system for continuous renal replacement therapy (CRRT) patients. Methods This was a single-center, randomized controlled trial that included patients who received CRRT at West China Hospital, Sichuan University, from June 2021 to June 2023. All patients underwent CRRT using an integrated citrate anticoagulation system and were randomized via a computer-generated sequence to be assigned to either a calcium-containing or a calcium-free replacement fluid group. General patient data and CRRT-related parameters were collected. The primary endpoint was the lifespan of the extracorporeal circuit, which was evaluated using Kaplan-Meier survival analysis. Secondary endpoints included CRRT-related parameters, hospital mortality rate, kidney function recovery rate, and complications. Results A total of 60 patients were randomly assigned, and 57 patients were finally included, with 29 (50.9%) in the calcium-containing replacement fluid group and 28 (49.1%) in the calcium-free replacement fluid group, comprising 109 sets of extracorporeal circuits (58 sets in the calcium-containing replacement fluid group and 51 sets in the calcium-free replacement fluid group). The median circuit lifespans were 52.25 (23.75, 72.00) hours in the calcium-containing replacement fluid group and 45.00 (24.00, 72.00) hours in the calcium-free replacement fluid group, with no statistically significant difference (Z=0.107, P=0.744). Kaplan-Meier survival analysis results indicated that there was no statistically significant difference in the survival rate of the extracorporeal circulation circuits between the two groups (Log-rank test, χ²=0.093, P=0.760). There were no significant differences between the calcium-containing replacement fluid group and the calcium-free replacement fluid group in sodium citrate infusion rate [179.00(171.66, 191.25) ml/h vs. 182.00(178.25, 192.00) ml/h, Z=0.685, P=0.737], pre-filter ionized calcium level [(1.02±0.11) mmol/L vs. (1.02±0.13) mmol/L, t=0.029, P=0.977], or post-filter ionized calcium level [(0.29±0.05) mmol/L vs. (0.26±0.07) mmol/L, t=1.945, P=0.055]. However, the calcium supplementation rate in the calcium-containing replacement fluid group was significantly lower than that in the calcium-free replacement fluid group, and the difference was statistically significant [4.00 (0, 9.19) ml/h vs. 30.50 (6.82, 41.00) ml/h, Z=2.830, P<0.001]. No statistically significant differences were found between the two groups in in-hospital mortality or renal function recovery rate (P>0.05). There was no statistically significant difference in the occurrence of hyponatremia and citrate accumulation between the calcium-containing replacement fluid group and the calcium-free replacement fluid group [1 episode (1.72%) vs. 2 episodes (3.92%), P=0.249; 2 episodes (3.45%) vs. 5 episodes (9.80%), P=0.598]. No other serious complications occurred in either group. Conclusions In the integrated citrate anticoagulation system for CRRT, the use of calcium- containing replacement fluid may be a safe and feasible alternative. Compared to calcium-free replacement fluid, calcium-containing replacement fluid can reduce the need for calcium supplementation and simplify clinical operations. However, due to the limitations of the single- center design and sample size, further large-scale, multicenter studies are required to verify the long-term safety and clinical application value.

Objective To evaluate the clinical efficacy of intraoperative transluminal angioplasty (ITA) performed simultaneously with autogenous arteriovenous fistula (AVF) creation in patients with small-diameter radial arteries. Methods This prospective interventional study enrolled stage 5 chronic kidney disease patients who were scheduled for forearm AVF creation at Haidian Hospital of Peking University Third Hospital between March 1, 2022, and February 28, 2023, and the inner diameter of the radial artery was less than 1.5 mm. All patients underwent radial artery ITA during AVF creation. Regular follow-up was conducted to assess AVF maturation at 4, 8, and 12 weeks, and AVF patency at 6 and 12 months. Results A total of 26 patients were included, all of whom successfully underwent AVF creation combined with radial artery ITA. Postoperative radial artery spasm occurred in 8 patients. One patient experienced loss of AVF bruit within 0.5 hours after surgery, which resolved after local manual massage. The overall technical success rate was 96.2% [25/26, 95% (confidence interval,CI) 80.4%-99.9%]. No patients experienced complications such as radial artery rupture or dissection. The proportion of patients achieving AVF maturation at 4, 8, and 12 weeks were 30.8% (8/26, 95% CI 14.3%-51.8%), 50.0% (13/26, 95% CI 29.9%-70.1%), and 92.3% (24/26, 95% CI 74.9%-99.1%), respectively. The median time to AVF maturation was 8.00 (4.00, 12.00) weeks. The primary patency rate at 6 months was 69.2% (18/26, 95% CI 48.2%-85.7%), and the secondary patency rate at 12 months was 92.3% (24/26, 95% CI 74.9%-99.1%). Conclusions Performing radial artery ITA simultaneously with AVF creation in patients with small-diameter radial arteries is feasible and safe, with favorable AVF maturation and long-term patency outcomes. This combined approach offers a viable option for establishing AVF in end-stage renal disease patients whose arterial diameter would otherwise be considered insufficient.

Objective To analyze the clinical characteristics and prognosis of IgA vasculitis-associated nephritis (IgAVN) patients presenting as nephrotic syndrome (NS) and compare it with IgA nephropathy (IgAN) to enhance the understanding of IgAVN. Methods It was a single-center retrospective study. The patients aged ≥14 years old diagnosed with IgAVN or IgAN and met the clinical criteria of NS at nephrology department of Peking Union Medical College Hospital between January 2001 and March 2022 were collected. The follow-up period was more than 6 months. The clinical and pathological data of the patients were collected. For patients who underwent renal biopsy after 2010, the proportion of sclerotic glomeruli and interstitial fibrosis in renal pathology were measured. The extrarenal characteristics and prognosis in IgAVN patients with NS were analyzed, and the short-term prognosis and potential risk factors between IgAN and IgAVN groups were compared. Results A total of 36 patients with IgAVN and 76 patients with IgAN were included in this study. The patients in the IgAVN group were younger than that in the IgAN group when renal biopsy was performed [23.00 (16.00, 43.00) years vs. 33.50 (27.75, 42.25) years, Z=-2.425, P=0.015]. Baseline serum creatinine [80.00 (60.94, 108.00) μmol/L vs. 113.50 (85.75, 159.25) μmol/L, Z=-3.564, P<0.001] and proportion of renin-angiotensin system inhibitors use (47.22% vs. 67.11%, χ2=4.049, P=0.044) were lower, and estimated glomerular filtration rate was higher [(110.08±93.42) ml·min^-1·(1.73 m²)^-1vs. (65.20±29.44) ml·min^-1·(1.73 m²)^-1, t=2.779, P=0.009] in the IgAVN group than those in the IgAN group. There were no statistical differences between the two groups in terms of gender distribution, disease duration, baseline blood pressure, urinary sediment red blood cell count, 24-hour urinary protein excretion, serum albumin, IgA and IgG levels (all P>0.05). Two patients did not receive immunosuppressive therapy, 4 patients received glucocorticoids only, and 30 patients received glucocorticoids combined with immunosuppressive agents (cyclophosphamide, mycophenolate mofetil, or cyclosporine) in the IgAVN group. Seven patients received monotherapy glucocorticoids and 69 patients received combination therapy in the IgAVN group. There was no statistical difference in the proportion of patients receiving glucocorticoids combined with immunosuppressive agents between the two groups (83.33% vs. 90.79%, χ2=0.697, P=0.404). Six months after discharge, the estimated glomerular filtration rate decline was more significant in the IgAVN group than that in the IgAN group [-8.76%(-25.45% ,1.74%) vs. 3.29%(-10.95%, 19.42%), Z=-2.982, P=0.003]. The multivariate linear regression analysis showed that the improvement rate of eGFR=-0.091+0.005×age (years)-0.196×disease classification (where disease classification was a binary variable, including IgAVN and IgAN, with IgAN as the reference), and the results indicated that IgAVN was correlated with the improvement rate of eGFR (t=-2.499, P=0.014). Further analysis of renal pathology in some patients revealed that IgAN group had higher level of baseline interstitial fibrosis than that in the IgAVN group [8.42%(4.68%, 18.70%) vs. 19.64% (7.47%, 37.23%), Z=-2.295, P=0.022]. Conclusions IgAVN patients presenting as NS achieve a comparable level of urinary protein to those with IgAN. However, the short-term decline of estimated glomerular filtration rate in the IgAVN group is significantly more pronounced than that in the IgAN group.

Objective To explore the protective effect of time-restricted fasting (TRF) on the kidneys of diabetic kidney disease (DKD). Methods Twelve 8-week-old male C57BL/6J mice were adaptively fed for 1 week, and then fed with the high-fat diet for 8 weeks. The mice were intraperitoneally injected with streptozotocin (50 mg/kg) for 5 days. After 2 weeks, if random blood glucose level was more than 16.7 mmol/L, it was considered that type 2 diabetes mellitus models had been successfully established. After an additional 8 weeks of feeding, urinary protein was presented, confirming the successful establishment of the DKD model. DKD mice were randomly divided into non-fasting group (DKD group) and fasting group (DKD TRF group), with 4 h feeding, 20 h fasting per day. Six mice were in each group, and continuously treated for 4 weeks. Body weight and blood glucose were monitored weekly, and blood and urine samples were collected to assess kidney function and blood lipid levels. Visceral fat and kidney tissues were collected and weighed after the mice were sacrificed. PAS staining, sirius red staining, and oil red O staining were used to observe the pathological changes in kidney tissues. Immunofluorescence was performed to analyze the expression levels of podocyte markers, kidney tubular injury markers, adipose differentiation-related protein, inflammatory cytokines, apoptosis-related molecules, and fibrosis markers. Results Compared with the DKD group, the DKD TRF group showed significant reductions in kidney weight, visceral fat mass, serum creatinine, blood urea nitrogen, urine protein quantity, triglyceride, total cholesterol, and low-density lipoprotein levels (all P<0.05). Oil red O staining and immunofluorescence revealed significantly reduced ectopic fat deposition of renal tissues in the DKD TRF group than that in the DKD group (both P<0.05). PAS staining showed reduced glomerular area and mesangial expansion in the DKD TRF group than those in the DKD group (both P<0.05). Immunofluorescence analysis showed higher positive area percentages of Wilms' tumor 1 and higher fluorescence intensity of podocin, while kidney injury molecule-1, neutrophil gelatinase-associated lipocalin, interleukin-6, tumor necrosis factor-α, caspase-3, α- smooth muscle actin, and collagen type I α1 had significantly reduced fluorescent areas in the DKD TRF group than those in the DKD group (all P<0.05). Sirius Red staining showed a decrease in the kidney fibrosis-positive area in the DKD TRF group than that in the DKD group (P<0.05). Conclusions TRF can reduce the kidney weight, visceral fat mass and blood lipid levels in DKD mice, and improve renal pathological damage and renal function, providing experimental evidence for the treatment of DKD.

Trimethyltin chloride (TMT), an organotin compound used as a heat stabilizer in plastics, can cause life-threatening poisoning if ingested excessively. This case report describes a 58-year-old woman who presented with fatigue, headache, convulsion, impaired consciousness, memory deficits, metabolic acidosis, severe hypokalemia, paradoxical alkaline urine, and a normal anion gap. Urinary TMT testing was positive, confirming a diagnosis of severe renal tubular acidosis due to acute TMT poisoning. Following treatment with potassium supplementation, acidosis correction, and supportive care, her symptoms improved. At a two-month follow-up, her serum potassium had normalized. Given that TMT poisoning typically presents with predominant neurological symptoms, often leading to initial neurological consultation, and rarely manifests primarily as renal tubular acidosis, this case aids in enhancing clinicians' awareness of TMT poisoning.

The patient was an elderly female who presented with proteinuria, with history of hypertension and diabetes mellitus. On admission, urine protein quantification was 0.96 g/24 h, serum albumin 36.9 g/L, serum creatinine 73.1 μmol/L, estimated glomerular filtration rate (eGFR) 77.8 ml·min^-1·(1.73 m²)^-1. Under light microscopy, there was deposition of pink, homogeneous, structureless material within the glomerular mesangium and renal interstitium. Immunofluorescence examination revealed deposition of IgG, kappa, and lambda along the capillary loops, and IgA deposition in the mesangial area.Anti-M-type phospholipase A2 receptor (PLA2R) antibody was positive. Congo red staining was positive, with characteristic apple- green birefringence observed under polarized light. Immunohistochemistry demonstrated positive staining for leukocyte chemotactic factor 2 (LECT2) protein in segmental glomeruli and renal interstitium. Mass spectrometry analysis identified LECT2 protein in the renal interstitium and PLA2R protein in the glomerular region. Final clinical diagnosis was LECT2-associated renal amyloidosis with stage Ⅱ membranous nephropathy (PLA2R-mediated) and IgA nephropathy. Literature review indicates this is the first reported case of LECT2-associated renal amyloidosis with PLA2R-mediated membranous nephropathy and IgA nephropathy. By reporting this case and reviewing the pathogenesis, clinical-pathological manifestations, and prognosis of such cases, clinicians' awareness of the disease may be raised.

Polyamines represent a class of cationic compounds that are widely distributed among organisms and participate in a diverse array of life activities. In recent years, there has been a growing number of studies that have focused on the significant role of maintaining polyamine homeostasis in the pathogenesis and intervention of autoimmune-related diseases. Systemic lupus erythematosus (SLE) is a common group of autoimmune diseases, with lupus nephritis (LN) representing the most common and severe form of target organ damage observed in SLE. This review summarizes the emerging role of polyamine metabolism in SLE or LN. Highlighting the biphasic regulatory effects of polyamine concentration changes, it explores the association of polyamine dysregulation with aberrant T and B cell activation, excessive interferon signaling, and autophagy dysfunction, with a view to informing novel preventative and therapeutic strategies for this challenging disease.

IgA nephropathy (IgAN) is the most common primary glomerular disease worldwide, with high heterogeneity and the risk of progression to end-stage kidney disease. To improve clinicians' diagnosis and treatment of IgAN, Clinical practice guidelines working group organized national nephrologists to revise and compile this article through several rounds of discussion on 60 common questions in clinical practice of IgAN. The content covered epidemiological features, pathogenesis, clinical manifestations, diagnostic approaches, therapeutic strategies, and prognostic evaluation of IgAN, with particular emphasis on the clinical application of targeted-release formulation of budesonide—the first targeted etiological treatment, marking a new era in IgAN management. Additionally, comprehensive discussions were provided on management strategies for IgAN patients in various clinical scenarios, such as blood pressure management, treatment of special populations, and post-transplant recurrence. This article aims to offer practical and standardized clinical guidance to optimize the precise treatment of IgAN and improve patients' prognosis.