Objective To explore the expression of type 2 complement receptor (CR2) in mesangial cells of the renal tissue in IgA nephropathy (IgAN) and its possible mechanism involved in complement C3 deposition. Methods The demographic data, samples of plasma and renal tissues of primary IgAN patients diagnosed by renal biopsy in the Guangdong Provincial People's Hospital from August 2021 to May 2022 were collected. According to the fluorescent intensity of mesangial complement C3 deposition, the patients were divided into complement C3 deposition ≥2+ group and complement C3 deposition <2+ group. The circulating IgA and complement C3 levels were detected by enzyme linked immunosorbent assay (ELISA). The influencing factors of kidney prognosis, plasma IgA and complement C3 levels were compared between the two groups. Immunofluorescence was used to detect the expression of IgA, complement C3 and CR2 in the renal mesangial cells of IgAN patients and normal renal tissues around renal carcinoma. Human mesangial cells were cultured in vitro and randomly divided into control group and experimental group. The experimental group was incubated with IgA protein (2 g/L) for 8 hours. The expressions of CR2 protein and mRNA were measured by Western blotting and real-time fluorescence quantitative PCR. The biological function of differential genes was analyzed by gene ontology (GO) and Kyto encyclopedia of genes and genomes (KEGG) enrichment analysis. Results A total of 75 patients with IgAN were included in this study, including 50 patients in the complement C3 deposition ≥2+ group and 25 patients in the complement C3 deposition <2+ group. The proportions of patients with urine red blood cell count negative, 1+, 2+ and 3+-4+ in the complement C3 deposition ≥2+ group were 2.0%, 8.0%, 18.0% 72.0%, respectively, which were more serious than those in the complement C3 deposition <2+ group (4.0%, 4.0%, 52.0%, 40.0%) (Z=-2.320, P=0.020). Meanwhile, the proportion of S1 in Oxford pathological classification in the complement C3 deposition ≥2+ group was higher than that in the complement C3 deposition <2+ group (68.0% vs. 40.0%, χ²=5.389, P=0.020), and there were no statistically significant differences in gender, age, 24-hour urinary protein, serum creatinine, other indicators of Oxford pathological classification between the two groups. ELISA results showed that plasma IgA concentration in the complement C3 deposition ≥2+ group was higher than that in the complement C3 deposition <2+ group [3.62 (2.95, 5.53) g/L vs. 2.72 (2.15, 4.24) g/L, Z=2.405, P=0.016], and the plasma complement C3 concentration was lower than that in the complement C3 deposition <2+ group [199.6 (116.0, 328.0) mg/L vs. 319.2 (158.3, 454.5) mg/L, Z=-2.383, P=0.017]. Spearman correlation analysis showed that the complement C3 deposition intensity was positively correlated with IgA deposition intensity in mesangial area (r_s=0.441, P<0.001). Immunofluorescence results showed that there was colocalization of IgA and complement C3 in the glomeruli of IgAN patients. The expression of CR2 in the kidney was consistent with complement C3 deposition, and CR2 was colocalization with complement C3. In vitro experiments, the expression of CR2 in IgA protein group was higher than that in the control group (P<0.05). GO and KEGG enrichment analysis found that IgA protein induced active changes in various pathways of mesangial cells. Conclusion IgA protein induces mesangial cells to express CR2 and participates in complement C3 deposition, which may be an important mechanism of complement C3 activation in IgAN.

Objective To investigate the urinary sediment findings and the clinicopathologic features of IgA nephropathy (IgAN) patients with acute kidney injury (AKI). Methods It was a retrospective study. The patients with renal biopsy-proven primary IgAN in Peking University First Hospital from January 31, 2013 to July 31, 2015 were selected. According to whether AKI occurred at renal biopsy or not, the patients were divided into AKI group and non-AKI group. Morning urine samples were obtained on the day of renal biopsy. Urine sediments, including various cells and casts, were examined. The clinical data, urinary sediments, and renal pathological changes were compared between the two groups. Logistic regression analysis was performed to identify the association between clinical pathological changes, urinary sediment indicators and AKI, or clinical pathological changes and urinary sediment indicators. Results There were 502 IgAN patients enrolled in this study, with age of (36.1±12.1) years old and 261 males (52.0%). The incidence of AKI was 11.4% (57/502) among the enrolled patients at the time of renal biopsy. Common causes of AKI included gross hematuria-induced AKI (10 cases), acute tubulointerstitial nephritis (10 cases), crescentic IgAN (9 cases), malignant hypertensive renal damage (6 cases), and multiple etioloqy or unknown etiology (22 cases). Compared with non-AKI group, AKI group had higher proportions of males and malignant hypertension, higher levels of proteinuria and urinary erythrocyte counts, and higher frequencies of gross hematuria, leukocyturia, renal tubular epithelial cells, and granular casts (all P<0.05). AKI group also had higher proportions of severe tubular atrophy/interstitial fibrosis (T2) and cellular/cellular fibrous crescent formation (C2) than non-AKI group (both P<0.05). Logistic regression analysis results showed that, there were statistically significant differences in the correlation between AKI and gender, 24 h urinary protein, urinary erythrocyte counts, granular casts and renal tubular atrophy/interstitial fibrosis (T) scores (all P<0.05). Hematuria, leukocyturia, red blood cell casts, white blood cell casts, granular casts, and fatty casts were correlated with endothelial hypercellularity (E) and cellular/cellular fibrous crescent formation (C) scores, respectively (all P<0.05). Hematuria was correlated with mesangial hypercellularity (M) scores (OR=2.613, 95% CI 1.520-4.493, P=0.001). Hematuria (OR=1.723, 95% CI 1.017-2.919, P=0.043) and fatty casts (OR=2.646, 95% CI 1.122-6.238, P=0.026) were correlated with segmental sclerosis or adhesion (S) scores. Leukocyturia (OR=1.645, 95% CI 1.154-2.347, P=0.006) and fatty casts (OR=2.344, 95% CI 1.202-4.572, P=0.012) were correlated with T scores. Epithelial cell cast was correlated with C scores (OR=1.857, 95% CI 1.174-2.939, P=0.008). Conclusions AKI is a common complication among IgAN patients with diverse etiology and more severe clinicopathological features. Urinary sediment findings can reflect renal pathological changes to some extent, and therefore assist in the clinical diagnosis and treatment of IgAN patients with AKI.

Objective To explore the relationship between the levels of serum complement C3 and C4 and the degree of renal pathological injury in patients with IgA nephropathy (IgAN). Methods It was a retrospective study. The clinical and pathological data of patients with primary IgAN diagnosed by renal biopsy in the Department of Nephrology of the Second People's Hospital of Qujing City, Yunnan Province from December 1, 2019 to December 31, 2022 were collected. According to the IgAN Oxford classification criteria, the patients were divided into mild renal pathological injury group (mild group, <3 pathologic types) and severe renal pathological injury group (severe group, ≥3 pathological types). The levels of serum C3 and C4 and other clinical data were compared between the two groups. Spearman correlation method was used to analyze the correlation between serum C3, C4 levels and estimated glomerular filtration rate (eGFR) during renal biopsy.Multivariate logistic regression model was used to analyze the influencing factors of the pathological injury degree in IgAN patients and the forest map depicted the effect of risk factors. Results A total of 164 IgAN patients were included in the study, including 77 males (47.0%), aged (35.5±12.9) years old. There were 60 patients in the mild group and 104 patients in the severe group. Compared with the mild group, the patients in the severe group were older, had higher levels of serum C4, serum uric acid, low density lipoprotein cholesterol and 24 h urinary protein, higher proportions of hypertension, glucocorticoids/immunosuppressant therapy, C3 deposition in renal tissues and microscopic hematuria, and had lower hemoglobin and serum C3 level (all P<0.05). The results of Spearman correlation analysis showed that the level of serum C3 was positively correlated with eGFR (r=0.303, P<0.001), and the level of serum C4 was negatively correlated with eGFR (r=-0.238, P=0.002). Multivariate logistic regression analysis results showed that serum C3 (every 0.01 g/L increase, OR=0.976, 95% CI 0.957-0.996, P=0.018), serum C4 (every 0.01 g/L increase, OR=1.091, 95% CI 1.020-1.166, P=0.011), hemoglobin (OR=0.969, 95% CI 0.950-0.988, P=0.002), and serum uric acid (OR=1.005, 95% CI 1.001-1.009, P=0.012) were independent related factors of renal pathological damage (severe injury /mild injury) in IgAN patients. Conclusions Serum C3 and C4 are independent related factors of the severity of renal pathological injury in IgAN patients.

Objective To analyze the long-term prognosis of IgA nephropathy (IgAN) with focal segmental glomerulosclerosis (FSGS) and the risk factors related to renal prognosis in children with IgAN-FSGS. Methods A retrospective study was concluded in IgAN-FSGS children who were followed up for more than 5 years and diagnosed by renal biopsy for the first time in the Eastern Theater General Hospital from January, 2004 to December, 2018. The end-point events of the study were entering end-stage kidney disease (ESKD) or estimated glomerular filtration rate (eGFR) decreased by ≥50% from baseline, which were defined as poor renal prognosis. Baseline clinicopathologic data of IgAN-FSGS children were compared between the end-point event group and the non-end-point event group. The cumulative renal survival rate of IgAN-FSGS children was calculated by Kaplan-Meier survival analysis. The influencing factors of poor renal prognosis in IgAN-FSGS children were analyzed by Cox proportional hazards model, and the diagnostic value was evaluated by the receiver operating characteristic curve (ROC curve) and area under the curve (AUC). The diagnostic value was verified by time dependent-ROC and time dependent-AUC. Results A total of 204 IgAN-FSGS children were enrolled in this study, of whom 132 cases were males (64.7%). The median age of renal biopsy was 16 (14, 17) years old. During a median follow?up time of 90.7 (71.7, 114.8) months, 57 cases (27.9%) reached the end-point events. Compared with the non-end-point event group (n=147), the end-point event group (n=57) had higher proportions of males and hypertension, higher levels of 24-hour urinary protein, serum creatinine, serum uric acid, urinary N-acetyl-β-D-glucosaminidase, urinary retinol binding protein, higher proportions of glomerular segmental sclerosis (S1) ≥25% and tubular atrophy/interstitial fibrosis (T1/T2), and lower levels of serum albumin, serum IgA, and serum IgG (all P<0.05). There was no statistical difference between the two groups in treatment (all P>0.05). Kaplan-Meier survival analysis showed that with entry of ESKD or eGFR decreased by ≥50% from baseline as the end-point events, the 5-year, 10-year, and 15-year cumulative renal survival rates in IgAN-FSGS children were 88.7%, 67.6%, and 50.7%, respectively. Multivariate Cox regression analysis showed that proteinuria >1 g/24 h (HR=3.702, 95% CI 1.657-8.272, P=0.001), hyperuricemia (HR=3.066, 95% CI 1.793-5.245, P<0.001), S1≥25% (HR=2.017, 95% CI 1.050-3.874, P=0.035), T1/T2 (HR=1.863, 95% CI 1.021-3.158, P=0.016) were the independent related factors for poor renal prognosis. ROC curve analysis showed that S1≥25% (AUC=0.605, P=0.021, sensitivity 26.3%, specificity 94.6%), T1/T2 (AUC=0.624, P=0.006, sensitivity 43.9%, specificity 81.0%), hyperuricemia (AUC=0.658, P<0.001, sensitivity 52.6%, specificity 78.9%), proteinuria>1 g/24 h (AUC=0.670, P<0.001, sensitivity 87.7%, specificity 46.3%) could accurately predict the renal outcome of IgAN-FSGS. Time dependent-ROC curve validation showed that the combined diagnosis of S1≥25%, T1/T2, hyperuricemia and proteinuria>1 g/24 h had a good predictive value for renal prognosis (3-year AUC=0.846 and 5-year AUC=0.777, respectively). Conclusions During a median follow-up of 90.7 months, 27.9% of IgAN-FSGS children have poor renal prognosis, and the 5-year, 10-year, and 15-year cumulative renal survival rates are 88.7%, 67.6%, and 50.7%, respectively. Urinary protein >1 g/24 h, hyperuricemia, T1/T2, and S1 ≥25% are the risk factors for renal prognosis in IgAN-FSGS children.

Objective To investigate the impacts of hierarchical management based on medical alliance on the patency of arteriovenous graft (AVG),and provide a basis for further exploration of optimal AVG management. Methods In this retrospective cohort study, clinical and follow-up data of patients with AVG established in the First Affiliated Hospital of Zhengzhou University from January 1, 2018 to December 31, 2021 were analyzed. Patients were divided into medical alliance group and non-medical alliance group according to whether they were under hierarchical management model, and the patency rate of AVGs and the incidence of clinical events were compared between the two groups. Results A total of 328 AVGs were included in this study, which were from 151 hemodialysis centers, including 189 AVGs (57.6%) from 72 centers in medical alliance group, and 139 AVGs (42.4%) from 79 centers in non-medical alliance group. The age of the patients was (55.57±11.80) years, among whom 130 (39.6%) were males and 126 (38.4%) were diabetic. The follow-up time of AVGs in this cohort was 15.5 (9.5, 26.2) months, with 15.4 (9.8, 25.2) months in medical alliance group and 15.5 (9.2, 27.3) months in non-medical alliance group. The incidence of thrombosis or occlusion (0.328 times/patient-year), graft dissection (0.007 times/patient-year), graft infection (0.030 times/patient-year), and catheter utilization (0.043 times/patient-year) in the medical alliance group were lower than those in the non-medical alliance group (0.589 times/patient-year, 0.040 times/patient-year, 0.054 times/patient-year and 0.147 times/patient-year, respectively), and there was no significant difference in clinic follow-up rates between the two group (1.91 times/patient-year vs. 1.94 times/patient-year). The median primary patency time was 17.4 (95% CI 11.3-23.5) months, the median primary assisted patency time was 32.6 (95% CI 25.0-40.2) months, and the median secondary patency time was 47.9 (95% CI 40.0-55.8) months in the medical alliance group, compared with 12.3 (95% CI 9.4-15.2) months, 19.4 (95% CI 14.3-24.5) months, and 34.6 (95% CI 29.3-39.9) months in the non-medical alliance group, respectively. Primary patency were significantly higher in the medical alliance group (77.4%, 62.2%, 39.9%, and 26.6%) than those in the non-medical alliance group (71.1%, 50.1%, 30.6%, and 13.4%) at 6, 12, 24, and 36 months (Log-rank test, χ²=4.504, P=0.034). Primary assisted patency were significantly higher in the medical alliance group (90.9%, 84.3%, 67.1%, and 46.1%) than those in the non-medical alliance group (89.2%, 75.7%, 42.0%, and 16.6%) at 6, 12, 24, and 36 months (Log-rank test, χ²=10.655, P=0.001). Secondary patency were significantly higher in the medical alliance group (96.8%, 91.8%, 84.2%, and 74.0%) than those in the non-medical alliance group (89.9%, 85.8%, 69.3%, and 47.5%) at 6, 12, 24, and 36 months (Log-rank test, χ²=11.634, P=0.001). Multivariate Cox regression analysis showed that it was a protective factor for primary patency (HR=0.708, 95% CI 0.512-0.980, P=0.037), primary assisted patency (HR=0.506, 95% CI 0.342-0.749, P=0.001) and secondary patency (HR=0.432, 95% CI 0.261-0.716, P=0.001) under the medical alliance model. Conclusion The hierarchical management based on medical alliances can improve the patency of AVGs and reduce the incidence of clinical events.

Objective To investigate whether caffeic acid phenethyl ester (CAPE) would improve peritoneal dialysis (PD)-associated peritoneal fibrosis by alleviating oxidative stress through activating nuclear factor erythroid-2-related factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway. Methods Thirty-two male Sprague-Dawley rats were randomly divided into four groups by the random number table: control (CON) group (0.9% normal saline 20 ml/d intraperitoneal injection), CAPE group (0.9% normal saline 20 ml/d+CAPE 10 mg·kg^-1·d^-1 intraperitoneal injection), PD group [4.25% glucose peritoneal dialysis fluid (PDF) 20 ml/d intraperitoneal injection with lipopolysaccharide 0.6 mg/kg intraperitoneal injection at day 1, 3, 5 and 7], and PD+CAPE group (CAPE 10 mg·kg^-1·d^-1 intraperitoneal injection in addition to PD group), with 8 rats per group. On day 28, rats were euthanized after peritoneal equilibration test, and then the parietal peritoneum and omentum were collected for follow-up tests. To further investigate the mechanism, primary peritoneal mesothelial cells (PMCs) of rats were isolated and cultured. The PMCs were stimulated with 2.5% glucose PDF and added with 5 μmol/L CAPE intervention. The Nrf2 inhibitor (ML385) was used to identify whether CAPE protected PMCs from PDF by activating the Nrf2/HO-1 pathway. Histopathological staining was used to detect structural changes of the peritoneum, and immunohistochemical analysis was performed on cleaved caspase-3, Bax, α-smooth muscle actin (α-SMA), fibronectin (FN), and typeⅠ collagen (Col-Ⅰ) protein. Western blotting was used to detect the protein expression of α-SMA, FN, transforming growth factor-β1 (TGF-β1), HO-1 and nuclear Nrf2 (N-Nrf2). The apoptosis detection kit was used to detect apoptosis and flow cytometry was used to detect reactive oxygen species (ROS) in PMCs. The malondialdehyde (MDA) and superoxide dismutase (SOD) activity detection kit were used to detect MDA content and SOD activity. Cell immunofluorescence was used to analyze the protein expression of Nrf2 in PMCs. Results Compared with the CON group, the PD group had thicker peritoneum, and the expression levels of cleaved caspase-3, Bax, α-SMA, FN, Col-Ⅰand MDA in peritoneum were significantly higher, while HO-1, N-Nrf2 protein expression and SOD activity were lower (all P<0.05). Compared with the PD group, the parietal peritoneum morphology of CAPE+PD group was improved, accompanied by reduced cleaved caspase-3, Bax, α-SMA, FN, Col-Ⅰ protein expression, and MDA content, while N-Nrf2, HO-1 protein expression, and SOD activity were higher (all P<0.05). Compared with the CON group, the PD group had significantly lower ultrafiltration volume and higher peritoneal permeability (both P<0.05). After CAPE intervention, the peritoneal transport function of the rats was significantly improved (P<0.05). In cultured PMCs, PDF inhibited nuclear translocation of Nrf2 and protein expression of HO-1, and upregulated intracellular ROS level. In addition, PDF increased cell apoptosis and the protein expression levels of α-SMA, TGF-β1 and FN (all P<0.05). CAPE activated nuclear translocation of Nrf2, increased HO-1 protein expression, downregulated intracellular ROS level, and partially reversed PDF-induced cell apoptosis and epithelial- mesenchymal transition (all P<0.05). The protective effects of CAPE on PMCs were partially abolished by ML385 (all P<0.05). Conclusions CAPE can reduce PD-induced PMCs apoptosis and epithelial-mesenchymal transition by attenuating oxidative stress, and significantly improve peritoneal fibrosis and ultrafiltration function. The beneficial effects of CAPE on peritoneum are related to activation of Nrf2/HO-1 pathway.

The aim of this study was to elucidate the protective effect of arbutin on cisplatin (Cis) induced renal tubular epithelial cell injury and its mechanism. Cell counting kit-8 was used to detect the viability of renal tubular epithelial cells. The toxicity of arbutin on renal tubular epithelial cells at different concentrations and the appropriate concentration of arbutin to protect cells against cisplatin were observed. The renal tubular epithelial cells were divided into control group, arbutin group, Cis group and arbutin+Cis group. Flow cytometry, quantitative real-time PCR and Western blotting were used to detect the levels of apoptosis and inflammation. The results showed that arbutin had no significant toxic effect on renal tubular epithelial cells in the mentioned concentration range (0-200 μmol/L). When the concentration of arbutin exceeded 100 μmol/L, it showed a protective effect on renal tubular epithelial cells. Arbutin intervention significantly reduced cisplatin-induced apoptosis of renal tubular epithelial cells and the increase of inflammation-related molecules p-p65 and interleukin-18. In addition, arbutin intervention reversed the cisplatin-induced reduction of Bcl-2 in renal tubular epithelial cells. These findings suggest that arbutin can attenuate cisplatin-induced renal tubular epithelial cell injury through anti-apoptotic and anti-inflammatory responses, which may be expected to be a new potential therapeutic drug for acute kidney injury.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a group of systemic small vasculitis characterized by the detection of ANCA in serum. Bactericidal permeability enhancing protein (BPI) is one of the target antigens of ANCA. BPI-ANCA-associated vasculitis is not common clinically, and the combination of bronchiectasis is not accidental. The paper reported a case of BPI-ANCA-associated vasculitis with renal damage combined with bronchiectasis. We reviewed relevant literature to explore the characteristics of BPI-ANCA-associated vasculitis and the correlation between bronchiectasis and ANCA-associated vasculitis, so as to improve the clinician's understanding on this disease.

The paper reported a patient under maintained hemodialysis for 11 years, with a large mass appeared in the right thigh after local injury. The mass was clinically considered as tumoral calcinosis combined with clinical, imaging and pathological findings. Several treatments such as enhancing dialysis adequacy, low calcium dialysate, calcimimetic agent, non-calcium- phosphorus binding agents, parathyroidectomy and intravenous infusion of sodium thiosulfate could not vanish the mass. Finally, the lump was surgically removed. The treatment of tumoral calcinosis in the hemodialysis patient can provide a instruction for similar situations in clinical practice.

Primary biliary cirrhosis/cholangitis is an autoimmune disease. Renal tubular acidosis is a common form in PBC cases, but Fanconi syndrome is rarely reported. The paper reported a 66-year-old female patient with fatigue, renal insufficiency and elevated bile duct enzymes. The patient presented with type 2 proximal renal tubular acidosis and complete Fanconi syndrome. Laboratory examinations showed high-titer-positive anti-mitochondrial antibodies, elevated serum IgM, and type 3 cryoglobulinemia. Renal biopsy revealed interstitial nephritis, and electron micrographs showed abnormal mitochondria in proximal tubular epithelial cells. The patient's renal function ameliorated, and acid-base imbalance and electrolyte disturbances were corrected after high-dose glucocorticoid treatment.

Pathogen detection is very important to improve the prognosis of patients with peritoneal dialysis-associated peritonitis. The paper reported a case of peritonitis caused by Ureaplasma parvum diagnosed by metagenomics next-generation sequencing （mNGS） technology. The patient was a middle-aged woman and hospitalized due to abdominal pain and muddy effluent. Anti-infective treatments such as ceftazidime and vancomycin were given but the effect was poor. The result of traditional culture was negative. Ureaplasma parvum was detected by mNGS. After using doxycycline， the patient's inflammation was controlled. It is suggested that mNGS plays an important role in the detection of the pathogens in peritoneal dialysis-associated peritonitis patients with negative culture. Through this case report and literature review， clinical experience is provided for the diagnosis and treatment in such patients.

Pediatric idiopathic nephrotic syndrome (INS) is characterized by massive albuminuria, hypoproteinemia, edema and hyperlipidemia, with a long course and high probability of relapse and prolongation. Long-term complications caused by long-term usage of hormones and immunosuppressants in children with INS seriously affect their physical and mental health and quality of life. Most children with steroid-sensitive nephrotic syndrome can be cured before adulthood, while some of them relapse in adulthood. Long-term prognosis of children with steroid-resistant nephrotic syndrome is poor. There have been few studies in China followed the long-term outcomes and its related factors of children with INS over 10 years. The paper reviewed the literatures on the long-term outcomes of children with INS, including renal survival, growth, mental health, learning and work, marriage and fertility, disease recurrence and long-term related complications, to explore the factors related to the poor long-term outcomes of children with INS and to assist in clinical decision-making and follow-up management.

Patients with chronic kidney disease (CKD) are at high risk for suffering sarcopenia, but there is no unified criteria for diagnosing sarcopenia in CKD patients. It is well known that skeletal muscle mass and function are the key parameters to define sarcopenia based on the consensus published internationally. Recently, the need for the accuracy and applicability of assessment tools has facilitated the development of high-resolution imaging measurement and ultrasound evaluation. Sarcopenia in CKD is underrecognized in China resulting in clinical missed diagnosis and misdiagnosis prevalently. This article reviews the research progress of epidemiology, evaluation, prevention and treatment of sarcopenia in CKD patients.