Objective To investigate the risk factors and prognosis of mitral regurgitation (MR) in patients with chronic kidney disease (CKD). Methods Clinical data were collected from CKD patients who were hospitalized at the Department of Nephrology, Xuanwu Hospital, Capital Medical University, from January 1, 2018, to December 31, 2019, and underwent echocardiography. Patients were followed up until November 1, 2021, with the endpoint being all-cause mortality.Logistic regression was used to analyze the risk factors of MR in CKD patients. Kaplan-Meier survival analysis was performed to plot the survival curve, with the Log?rank test comparing the survival rate. Multivariate Cox regression analysis was used to identify the risk factors of death in CKD patients. Results It was a retrospective single-center study. A total of 555 CKD patients were included, with 262 patients developing MR. Of whom, 212 patients had mild MR (80.9%), 44 patients had modreate MR (16.8%), 6 patients had severe MR (2.3%). The prevalence of MR among patients with CKD stages 1 to 5 was 21.9%, 33.0%, 45.9%, 51.9%, and 64.6%, and the prevalence of moderate to severe MR was 0, 5.6%, 7.4%, 10.1%, and 15.9%. Multivariate logistic regression analysis revealed that male sex (OR=1.579, 95% CI 1.008-2.476, P=0.046), presence of chronic heart disease (OR=2.263, 95% CI 1.398-3.662, P=0.001), CKD stage 4-5 (with CKD stage 1-3 as reference, OR=1.744, 95% CI 1.007-3.019, P=0.047), and decreasing hemoglobin levels (OR=0.985, 95% CI 0.975-0.996, P=0.006) were the associated factors for MR in CKD patients. Kaplan-Meier survival analysis indicated higher all-cause mortality (Log-rank, χ2=8.094, P=0.004) in the MR group compared to the non-MR group. Multivariate Cox regression analysis showed that increasing age (HR=1.072, 95% CI 1.042-1.104, P<0.001), elevating blood phosphorus (HR=2.782, 95% CI 1.122-6.895, P=0.027), MR (HR=1.962, 95% CI 1.002-3.839, P=0.049) and decreasing albumin (HR=0.927, 95% CI 0.886-0.970, P=0.001) were independent associated factors for all-cause death in CKD patients. Conclusions The overall prevalence of MR and the prevalence of moderate to severe MR are increasing with the progression of CKD. Male sex, presence of chronic heart disease, CKD stage 4-5 and decreasing hemoglobin levels are risk factors for MR in CKD patients. MR is an independent risk factor for all-cause mortality in CKD patients.

Objective To investigate the distribution and drug resistance of common pathogens causing urinary tract infection (UTI) in children in Beijing, so as to provide reference for clinical rational use of antibiotics. Methods It was a retrospective cohort study. The results of clinical data, urine culture and drug sensitivity in children with urinary infection treated in the Department of Nephrology, Children's Hospital Affiliated to Capital Institute of Pediatrics from June 2018 to June 2018 were retrospectively analyzed. According to the diagnostic criteria of "Chinese expert consensus on the diagnosis and treatment of UTI (2015 edition) - Complicated urinary tract infection", the children were divided into complex group and simple group according to whether they had complicated factors, and the pathogenic factors of the complex group were analyzed. The χ² test was used to compare the distribution of pathogenic bacteria in urine culture and the resistance rate of Escherichia coli to common antibiotics between the two groups. Results A total of 187 children with UTI were enrolled in this study. The age ranged from 1 month after birth to 17 years old, and the median age was 8 months. There were 88 males (47.1%) and 99 females (52.9%), and the male/female ratio was 1:1.125. Male infants accounted for 79.5% (70/88) of male infants and female infants accounted for 48.5% (48/99) of female infants. There were 45 cases (24.1%) in the simple UTI group and 142 cases (75.9%) in the complicated UTI group. A total of 216 strains of pathogens were isolated, mainly Gram-negative bacteria (151/216, 69.9%), of which Escherichia coli was the most common (86/216, 39.8%). The second was gram-positive bacteria (57/216, 26.4%), among which Enterococcus faecium (37/216, 17.1%) was the most common. The positive rate of Escherichia coli infection in the simple UTI group was significantly higher than that in the complicated UTI group [71.1% (32/45) vs. 31.6% (54/171), χ²=23.234, P<0.001], and the positive rate of Klebsiella pneumoniae, Pseudomonas aeruginosa, Enterococcus faecium and fungal infection in the simple UTI group was significantly lower than those in the complicated UTI group. However, the differences were not statistically significant (all P>0.05). The resistance rate of Escherichia coli to ampicillin was the highest in children with UTI [91.9% (79/86)], and it was sensitive to amikacin, meropenem, imipenem, piperacillin/tazobactam, cefepime, piperacillin, cefazolin, cefoperazone/sulbactam. The drug resistance rates were 5.8% (5/86), 5.8% (5/86), 9.3% (8/86), 10.5% (9/86), 14.0% (12/86), 15.1% (13/86), 18.6% (16/86) and 18.6% (16/86), respectively. The resistance rate of Escherichia coli infection to ceftriaxone in the complicated UTI group was significantly higher than that in the simple UTI group [59.3% (32/54) vs. 24.4% (11/32), χ²=4.977, P=0.026]. Eight fungi (3.7%) were susceptible to fluconazole, voriconazole, itraconazole and amphotericin B. Conclusions The main pathogens of UTI in children are Gram-negative bacteria, among which Escherichia coli is the most common pathogen, but the proportion of infection has a downward trend in recent years. The resistance rate of ceftazidime and ceftriaxone is relatively low, which can be used as empirical drugs for children with UTI in this region.

Objective To investigate the efficacy of rituximab (RTX) monotherapy in the treatment of adult minimal change disease (MCD). Methods This study was a case series analysis. The clinical data of 10 MCD patients who received RTX monotherapy at the Department of Nephrology, Zhongda Hospital, Southeast University, from January 2021 to October 2023 were retrospectively conducted. Results The onset age of the 10 patients was (48.4±21.2) years old, including 7 males and 3 females. Four patients (4/10) were aged 60 or above. One patient (1/10), 6 patients (6/10) and 3 patients (3/10) were treated with rituximab once, 2 times and 3 times, respectively. The follow-up duration was (327.1±141.6) d. All 10 patients achieved complete remission within 3 months, with 4 cases (4/10) achieving complete remission within 1 month. The mean time to remission was 35.7 d. During the follow-up period, none of the 10 patients experienced relapse. No significant adverse reactions were observed during treatment and follow-up. Conclusion Rituximab monotherapy demonstrates effective treatment outcomes in patients with MCD, but multi-center, large sample clinical validation is required. Long-term follow-up is necessary to assess its sustained efficacy and safety.

Objective To observe the role of complement C3 in the process of renal interstitial fibrosis. Methods Renal interstitial fibrosis model was established by unilateral ureteral obstruction (UUO) in male C3-deficient (C3KO) mice and age-matched C57BL/6 wild type (WT) mice (8-12 weeks of age). Mice were randomly divided into 4 groups, including sham operation in WT group (WTcontrol) (n=6), UUO operation in WT group (WTuuo) (n=6), sham operation in C3-deficient group (C3KOcontrol) (n=6), and UUO operation in C3-deficient group (C3KOuuo) (n=6). Tubular interstitial fibrosis was observed by both HE staining and Masson staining. The expression of C3, trypsin (tryptase), angiotensinⅡ (AngⅡ), transforming growth factor β1 (TGF-β1), and matrix metalloproteinase-9 (MMP?9) was detected by immunohistochemical staining. Chymase level were assessed by immunofluorescence staining. The levels of AngⅡ and C3 cleavage fragments C3a and MMP?9 were determined by enzyme-linked immunosorbent assay. The change in renin mRNA was determined by real-time PCR. The changes of chymase, renin, and TGF-β1 were detected by Western blotting. Results Compared with the WTcontrol group mice, the WTuuo group mice showed significant renal tubular injury, renal interstitial fibrosis, increased infiltration of mast cells, and significantly increased expression of C3, C3a, chymase, renin, AngⅡ, TGF-β1, and MMP?9 in the renal tissue (all P<0.05). Compared with the WTuuo group mice, the renal tubular injury and renal interstitial fibrosis in the C3KOuuo group mice were significantly reduced, and C3 and C3a were not detected in renal tissue. Mast cells infiltration was reduced, and the expression of chymase, renin, AngⅡ, TGF-β1, and MMP?9 was weakened (all P<0.05). Conclusion C3/C3a can participate in the recruitment and activation of mast cells to release chymase in kidney interstitial fibrosis, and promote the expression of renin, AngⅡ, TGF-β1, MMP 9 and other substances, thus aggravating kidney injury.

This paper reports a case of hypotension caused by superior vena cava stenosis due to hemodialysis catheter. A 65-year-old female maintenance hemodialysis patient presented with intolerable hypotension during dialysis. The dialysis access was tunnel-cuffed catheter. Computed tomography angiography and digital subtraction angiography revealed occlusion at the junction of the superior vena cava and the right atrium. After the superior vena cava was opened by endovascular treatment, the patient's blood pressure returned to normal and could tolerate 4 hours of regular hemodialysis. Reviewing relevant literature, occlusion of superior vena cava is one of the causes of hypotension in maintenance hemodialysis patients, and endovascular treatment to open the occluded superior vena cava can effectively correct this kind of hypotension.

IgA vasculitis (IgAV) is more common in children with vasculitis, while antineutrophilcytoplasmicantibodies (ANCA) associated vasculitis (AAV) in children is relatively rare. We report a case of IgA vasculitis nephritis with ANCA positive in a child. The clinical manifestations of the child were consistent with rapidly progressive nephritis syndrome, and the serum MPO-ANCA was strongly positive. Pathologically, crescentic glomerulonephritis was mainly presented, accompanied by a large amount of IgA deposition in the mesangial area. After treatment with glucocorticoids, rituximab and symptomatic treatment, the child's condition was relieved. This report aims to improve the understanding of the diagnosis and treatment of renal damage caused by vasculitis in children.

Chronic kidney disease (CKD) patients with concurrent renal anemia and thalassemia present complex pathogenesis involving various iron metabolism disorders, which are among the key factors contributing to suboptimal therapeutic outcomes. This paper reports the clinical experience of treating five CKD stage 3-4 patients with thalassemia using roxadustat. The treatment outcomes demonstrated that all patients experienced significant improvements in anemia, and no cases of iron overload were observed throughout the follow-up period. These findings suggest that roxadustat effectively increases hemoglobin levels in patients with renal anemia and thalassemia while maintaining a low risk of iron overload, providing a potential therapeutic option for these challenging cases.

Acute kidney injury during pregnancy (P?AKI) threatens the health of both the mother and fetus, which should be given sufficient attention. During pregnancy, the kidneys undergo a series of physiological changes to adapt to the demands from the mother and infant, leading to the kidneys more susceptible to damage than non pregnant individuals. This article analyzes the pathophysiological changes, causes, diagnostic criteria, related diseases, and therapeutic measures of P?AKI. It also points out that for severe preeclampsia, thrombocytopenia syndrome, and acute fatty liver disease, the pregnancy should be terminated upon diagnosis. While for thrombotic thrombocytopenic purpura and hemolytic uremic syndrome, plasma exchange should be the main treatment. Further analysis of the dialysis indications for P?AKI is aimed at providing reference for accurate clinical diagnosis and effective treatment, thereby improving the survival rates of pregnant women and fetuses.

Membranous nephropathy (MN) is an organ-specific autoimmune disease, which is the main cause of nephrotic syndrome in adults. In 70%-80% of patients,MN occurs without an identifiable underlying cause. Regarding primary MN (PMN), 70% of which are associated with M-type phospholipase A2 receptor (PLA2R). At present, the treatment of MN primarily involves non-specific immunotherapy, such as immunosuppressants and B cell depletion. This review focused upon the mechanism of immune response in PLA2R-associated MN, aiming to provide theoretical basis and direction for specific immunosuppressive therapies in MN.

Extracellular vesicles (EVs) are communication vectors between cells and organs, which have been demonstrated new potential role in the pathogenesis, diagnosis, and treatment of kidney diseases. This paper describes the role of EVs in intercellular and inter organ communication in diabetic nephropathy by reviewing the biological properties of EVs, EVs-mediated organ-organ crosstalk, cell-cell crosstalk in diabetic nephropathy, and the role of EVs in the diagnosis and treatment of renal diseases. These insights aim to provide a theoretical basis for a more comprehensive understanding of the role of EVs in the pathogenesis and progression of diabetic nephropathy.

Chronic kidney disease (CKD) is a common and frequently-occurring disease in China. When CKD develops to end stage, it requires renal replacement therapy. Hemodialysis and peritoneal dialysis are currently the main renal replacement therapies. As the "lifeline" of dialysis patients, the quality of dialysis access directly affects the hospitalization and survival rate of patients. Therefore, it is of great significance to strengthen the study of dialysis access. At present, a number of clinical guidelines and expert consensus on dialysis access have been issued at home and abroad. However, with the development of new medical technology, the knowledge about dialysis access is constantly updated, especially the clinical application of new devices, equipment and new evidence of evidence-based medicine, which expands the diagnosis and treatment strategy of the establishment and maintenance of dialysis access. Therefore, it is necessary to compile a guideline for the diagnosis and treatment of dialysis access suitable for the Chinese population. In view of this, the Chinese Society of Nephrology organized an expert group to compile the "China Guidelines for Dialysis Access (2024)". This guideline refers to relevant domestic and foreign guidelines and expert consensus, integrates the clinical experience of Chinese dialysis access experts, systematically introduces dialysis access establishment, maintenance, monitoring, follow-up, and training of access doctors. In the process of preparation, the expert group, in accordance with the principle of rigor and conciseness, referred to the format of international guidelines, put forward the main points of diagnosis and treatment, and illustrated them case by case. This guideline reflects latest trends and perspectives in diagnosis and treatment. It is of great value to further strengthen the understanding of dialysis access, standardize the diagnosis and treatment system of dialysis access, formulate reasonable treatment principles, prolong the use time of dialysis access, and improve the quality of patients' lives. This guideline can be used as a reference for medical workers in clinical practice.