Objective To investigate the effects of hyperuricemia on the prognosis of IgA nephropathy (IgAN) using propensity score matching (PSM) method. Methods IgAN patients proven by biopsy were included. PSM was used to match patients. Kaplan-Meier method was used for survival analysis, and Cox regression analysis was used to analyze the effects of hyperuricemia on IgAN prognosis. Primary outcome events were defined as death, or end-stage renal disease (dialysis, transplantation), or a decrease in estimated glomerular filtration rate (eGFR) greater than 40%. Renal outcome was defined as end-stage renal disease (dialysis, transplantation), or a decrease in eGFR greater than 40%. Results A total of 1 454 IgAN patients were included in this study, including 850 females and 604 males. Uric acid level was (368.26±92.87) μmol/L in the males, and (277.23±92.71) μmol/L in the females. The median follow-up time was 85.00(56.10, 106.33) months. During the follow-up period, a total of 134 patients reached the primary outcome events, including 5 deaths, 24 dialysis patients, 5 kidney transplant patients, and 100 patients with eGFR decreased by more than 40%. After 1∶1 matching, 131 males and 159 females in the hyperuricemia group were successfully matched with 131 males and 159 females in the normal uric acid group, and there was no significant statistical difference in each parameter in baseline between the hyperuricemia group and normal uric acid group after matching. Kaplan-Meier survival analysis showed that either before or after matching, the incidence of primary outcome events in male or female patients with hyperuricemia was higher than those with normal uric acid, but there was no statistically significant difference in incidence of primary outcome events between female hyperuricemia group and female normal uric acid group after matching (Log-rank test, χ²=3.586, P=0.058). Cox proportional hazard regression model showed that, in the pre-match fully adjusted model, the hazard ratio (HR) of entering primary outcome events was 2.29-fold (95%CI 1.27-4.11, P=0.006) for men with hyperuricemia and 1.85-fold (95%CI 1.01-3.37, P=0.045) for women with hyperuricemia compared with those with normal uric acid. In the post-match fully adjusted model, the HR of entering primary outcome events was 2.41-fold (95%CI 1.18-4.93, P=0.016) for men with hyperuricemia and 1.83-fold (95%CI 0.91-3.67, P=0.091) for women with hyperuricemia compared with those with normal uric acid. In the pre-match fully adjusted model, the HR of entering renal outcome events was 2.68-fold (95%CI 1.47-4.88, P=0.001) for men with hyperuricemia and 1.81-fold (95%CI 0.99-3.33, P=0.056) for women with hyperuricemia compared with those with normal uric acid. In the post-match fully adjusted model, the HR of entering renal outcome events was 2.89-fold (95%CI 1.36-6.15, P=0.006) for men with hyperuricemia and 1.81-fold (95%CI 0.88-3.72, P=0.106) for women with hyperuricemia compared with those with normal uric acid. Conclusion Hyperuricemia may be associated with IgAN progression, and it has a more significant effect on male IgAN patients.

Objective To provide clinical experience for the diagnosis and treatment of spontaneous renal hemorrhage through retrospective analysis of clinical features, imaging manifestations, underlying causes, treatment, and prognosis of spontaneous renal hemorrhage. Methods By searching hospital information system, medical records scanning system, department of the interventional vascular surgery registry system, and picture archiving and communication systems, the patients with spontaneous renal hemorrhage admitted to Peking University First Hospital between January 1, 2000 to April 10, 2020 were enrolled. The clinical manifestations, investigations, imaging features, treatment, and prognosis of patients were retrospectively reviewed. The diagnostic efficiency and the accuracy of etiological diagnosis of renal hemorrhage by imaging examinations such as ultrasound, computed tomography (CT), magnetic resonance imaging (MRI), and angiography were compared and evaluated. Results A total of 50 patients with 51 events of spontaneous renal hemorrhage were enrolled in the study. Laboratory tests showed hemoglobin was (103.3±29.4) g/L. The most common clinical features were flank or abdominal pain (48 cases, 96.0%), fever (17 cases, 34.0%), nausea (10 cases, 20.0%), vomiting (9 cases, 18.0%), and gross hematuria (4 cases, 8.0%). Nine patients (18.0%) experienced hypovolemic shock (systolic pressure<90 mmHg). With an initial assessment of the imaging method, the diagnostic accuracy of bleeding was 98.0%(49/50), yet the accuracy of underlying causes was 56.0%(28/50). The diagnostic accuracy of bleeding was 100.0%(25/25) by non-contrast abdominopelvic CT. The most common cause of spontaneous renal hemorrhage syndrome was renal tumors (27 cases, 54.0%), among which angiomyolipoma occurred most frequently (20 cases, 40.0%). Other causes included renal cyst (10 cases, 20.0%), autoimmune diseases (4 cases, 8.0%), bleeding diathesis (3 cases, 6.0%), and idiopathic renal hemorrhage (6 cases, 12.0%). Twelve patients (24.0%) received conservative management, 29 patients (58.0%) underwent interventional embolization therapy, and 11 patients (22.0%) received nephrectomy. The success rate on first embolization therapy was 86.2%(25/29), and approximately 13.8%(4/29) required second embolization therapy or nephrectomy. Conclusions Spontaneous renal hemorrhage has no specific clinical features and is easy to be underdiagnosed or misdiagnosed. Non-contrast CT scan has a high diagnostic value for renal bleeding. Comprehensive judgement consisting of clinical features, laboratory tests, imaging manifestations and pathological examinations should be relied on for finding the underlying causes. Prompt diagnosis and management can guarantee a better prognosis.

Objective To compare the advantages and disadvantages of several formulas for estimated glomerular filtration rate (eGFR) based on serum creatinine in elderly patients with chronic kidney disease (CKD) over 60 years old. Methods CKD patients aged≥60 years old in Beijing Hospital from January 2012 to October 2017 were selected as subjects. Measured glomerular filtration rate (mGFR) was detected by ^99mTc-DTPA renal dynamic imaging and used as a reference standard. According to the mGFR value, the patients were divided into 4 groups: mGFR<30 ml·min^-1·(1.73 m²)^-1 group, 30≤mGFR<45 ml·min^-1·(1.73 m²)^-1 group, 45≤mGFR<60 ml·min^-1·(1.73 m²)^-1 group and mGFR≥60 ml·min^-1·(1.73 m²)^-1 group. The deviation of each formula was compared by Bland-Altman scatter chart, and the accuracy of each formula was evaluated by the proportion of eGFR within mGFR (1±30%) (P30) and root mean square error (RMSE). Wilcoxon paired rank sum test was used to compare the deviation of each formula, and McNemar test was used to compare the difference of P30 among these formulas. Results A total of 628 patients with CKD were enrolled in this study. The median age was 76.0(71.0, 81.0) years old. The median serum creatinine and mGFR were 110.0(86.0, 152.0) μmol/L and 42.90(29.88, 55.68) ml·min^-1·(1.73 m²)^-1, respectively. Each eGFR formula based on serum creatinine overestimated glomerular filtration rate in varying degrees. Among them, the accuracy of Berlin Initiative Study (BIS) formula and full age spectrum (FAS) formula was the best (P30 were 68.3% and 68.0% respectively), followed by the Chinese race coefficient of Chronic Kidney Disease Epidemiology Collaboration (C-CKD-EPI) formula (P30 was 65.4%). The accuracy of the other formulas was poor. In terms of deviation, C-CKD-EPI formula was the best (0.27). In the group of mGFR<30 ml·min^-1·(1.73 m²)^-1, the accuracy of all formulas was poor, and the accuracy of FAS formula was slightly better than that of other formulas (P30 was 51.0%). In the group of 30≤mGFR<45 ml·min^-1·(1.73 m²)^-1, the deviation of C-CKD-EPI formula was the smallest (3.11). In terms of accuracy, BIS and FAS formulas were better than others, and the P30 were 64.6% and 63.0% respectively. In the group of 45≤mGFR<60 ml·min^-1·(1.73 m²)^-1, the deviation of C-CKD-EPI formula was also the smallest (0.72), and the accuracy of BIS formula was the best (P30 was 82.5%), followed by FAS formula (P30 was 79.7%). In the group of mGFR≥60 ml·min^-1·(1.73 m²)^-1, the deviation and accuracy of Xiangya formula were the best (the deviation and P30 were -0.53 and 96.5% respectively), and the P30 of BIS and C-CKD-EPI formulas were 87.6% and 87.6%, respectively. Conclusions In the elderly patients with CKD over 60 years old, the accuracy of eGFR based on serum creatinine increases with the increase of mGFR. BIS and FAS formulas are recommended first. The accuracy of each formula is poor in patients with severe renal insufficiency.

Objective To investigate the composition of the renal disease spectrum and epidemiological characterisics for renal biopsy cases in Xinjiang Uygur Autonomous Region. Methods The clinical and pathological data of 10 684 renal biopsy cases from 12 hospitals in Xinjiang Uygur Autonomous Region from August 1986 to December 2019 were collected and the composition of renal diseases and pathological types were analyzed retrospectively. Results Among the 10 684 renal biopsy cases with 5 595 males and 5 089 females, 7 804 cases (73.04%) were Han nationality, 2 357 cases (22.06%) were Uygur nationality and 523 cases (4.90%) were other nationalities. Among the 10 684 cases of renal biopsy, primary glomerular disease, secondary glomerular disease, tubulointerstitial disease, end-stage renal disease, genetic and congenital disease and post transplant glomerular disease were 8 533 cases (79.87%), 1 740 cases (16.29%), 229 cases (2.14%), 121 cases (1.13%), 46 cases (0.43%) and 15 cases (0.14%), respectively. The distribution of kidney diseases in Han, Uygur and other nationalities (except Han and Uygur in this region) was the same as that in general. There was no significant difference in disease type composition between Han and Uygur, Han and other nationalities, and Uygur and other nationalities (all P>0.05). Among the 8 533 cases of primary glomerular diseases, the top five pathological types were IgA nephropathy (3 095 cases, 36.27%), mesangial proliferative glomerulonephritis (2 008 cases, 23.53%), membranous nephropathy (1 503 cases, 17.61%), minimal glomerulopathy (567 cases, 6.64%) and focal segmental glomerulosclerosis (494 cases, 5.79%). The top five pathological types of primary glomerular diseases were different between Han and Uygur, and Han and other nationalities (both P<0.01). There was no statistically significant difference between Uygur and other nationalities in the top five pathological types of primary glomerular diseases (P=0.113). Among 1 740 cases of secondary glomerular diseases, the top five pathological types were lupus nephritis (517 cases, 29.71%), Henoch-Sch?nlein purpura nephritis (304 cases, 17.47%), diabetic glomerulosclerosis (285 cases, 16.38%), benign renal arteriosclerosis (196 cases, 11.26%) and systemic vasculitis (101 cases, 5.80%). It was different between Han and Uygur, Han and other nationalities, and Uygur and other nationalities in the top five pathological types of secondary glomerular diseases. Conclusions Primary glomerular disease accounts for 79.87% of renal diseases in Xinjiang Uygur Autonomous Region. IgA nephropathy is the main pathological type, followed by mesangial proliferative glomerulonephritis and membranous nephropathy. The most common pathological type of secondary glomerular disease in this region is lupus nephritis, followed by Henoch-Sch?nlein purpura nephritis and diabetic glomerulosclerosis. The top five pathological types of primary glomerular diseases and secondary glomerular diseases are different in different ethnic groups in Xinjiang Uygur Autonomous Region.

Objective To assess the impact of kidney damage on the progression and prognosis of coronavirus disease 2019 (COVID-19) patients. Methods The databases including CNKI, Wanfang Chinese Academic Journal Database, Pubmed, EMBASE and Cochrane databases were searched. The data retrieval period was from December 2019 to June 2020. During this period, RevMan 5.2 was used to extract and analyze data from the literature. Results In this study, 15 articles, covering 11 448 COVID-19-related cases, were selected from the target databases. Meta-analysis results indicated that, for COVID-19 patients with acute kidney injury (AKI), the proportion of COVID-19 patients with AKI who received intensive care unit (ICU) treatment was significantly higher than that of patients without AKI (OR=10.83, 95%CI 9.43-12.45, Z=33.53, P<0.001). Among them, the Asian group of COVID-19 patients with AKI accounted for 3.4% of all COVID-19 patients. The Asian group of COVID-19 patients with AKI who received ICU treatment accounted for 74.1% of all COVID-19 patients with AKI. Meta-analysis showed that the proportion of COVID-19 patients with AKI in the Asian group receiving ICU treatment was significantly higher than that of COVID-19 patients without AKI (OR=18.66, 95%CI 9.85-35.34, Z=8.98, P<0.001). COVID-19 patients with AKI in the European and American groups accounted for 36.5% of all COVID-19 patients, and the European and American groups of COVID-19 patients with AKI who received ICU treatment accounted for 53.3% of all COVID-19 patients with AKI. Meta-analysis showed that the proportion of COVID-19 patients with AKI in the European and American groups receiving ICU treatment was significantly higher than that of COVID-19 patients without AKI (OR=10.58, 95%CI 9.18-12.21, Z=32.40, P<0.001). The death risk of COVID-19 patients with AKI was significantly higher than that of patients without AKI (OR=56.46, 95%CI 15.86-200.96, Z=6.23, P<0.001). COVID-19 patients with renal impairment had a higher risk of worsening and death than those without renal impairment (OR=6.40, 95%CI 4.14-9.90, Z=8.36, P<0.001). Subgroup analysis showed COVID-19 patients with positive urine protein had a higher risk of worsening and death than those without positive urine protein (OR=6.27, 95%CI 3.88-10.14, Z=7.49, P<0.001), and COVID-19 patients with elevated serum creatinine had a higher risk of worsening and death than those without elevated serum creatinine (OR=7.13, 95%CI 2.58-19.72, Z=3.79, P<0.001). Conclusions Patients with COVID-19 combined with AKI or only with positive urine protein and elevated serum creatinine are the risk factors for aggravation and even death. It is recommended that, in the diagnosis and treatment of COVID-19 patients, an optimization plan should be adopted to avoid or reduce the burden on the kidneys, meanwhile the patients' kidney damage should be paid closely attention to for protection and treatment in the early stage to avoid the occurrence of AKI. For patients who already suffered from AKI, replacement therapy, which would prevent these patient's condition from getting worse or even death, should be promptly implemented to alleviate the impact of kidney damage.

Objective To investigate the role of mitofusion 2 (Mfn2) in high glucose (HG)-induced endoplasmic reticulum stress (ERS) and apoptosis of podocytes. Methods (1) Streptozocin was used to induce a diabetes mellitus (DM) rat model. Renal histopathological changes in rats were observed by HE staining. Expression of Mfn2 and CCAAT/enhancer-binding protein homologous protein (CHOP) in glomeruli was observed by immunohistochemistry. Protein levels of Mfn2, protein kinase RNA-like ER kinase (PERK), phospho(p)-PERK, and CHOP in glomeruli were analyzed by Western blotting. (2) Conditionally immortalized human podocytes (HPC) cultured in vitro were divided into control, mannitol (MA) and HG groups. Expression of Mfn2 was observed by immunofluorescence. Protein levels of Mfn2, p-PERK, PERK and CHOP in HPC were analyzed by Western blotting. Podocyte apoptosis in each group was evaluated by flow cytometry with AnnexinⅤ-PE/7AAD double staining method. (3) HPC were divided into control, HG, HG+Mfn2-Myc plasmid-transfected and HG+control plasmid-transfected groups. Protein levels of Mfn2, p-PERK, PERK and CHOP in HPC were analyzed by Western blotting. Expression of CHOP was observed by immunofluorescence. Mitochondrial membrane potential in each group was observed by mitochondrial membrane potential assay kit with JC-1. Podocyte apoptosis in each group was evaluated by flow cytometry with AnnexinⅤ-PE/7AAD double staining method. Results (1) Compared with the control group, the glomerular mesangial matrix of the DM group rats was significantly proliferated, and the expression of Mfn2 was down-regulated with the expression of ERS-related proteins p-PERK/PERK and CHOP up-regulated (all P<0.05). (2) Compared with the control group, Mfn2 was down-regulated and p-PERK/PERK and CHOP were up-regulated in HPC of HG group (all P<0.05). Apoptosis of HPC was also increased in HG group. There was no significant difference in the above indicators between the control group and the mannitol group (all P>0.05). (3) Compared with the HG group, mitochondrial membrane potential of HPC was alleviated and apoptosis of HPC was decreased in HG+Mfn2-Myc plasmid-transfected group (P<0.05). P-PERK/PERK and CHOP were down-regulated in HG+Mfn2-Myc plasmid-transfected group (both P<0.05). There was no significant difference in the above indicators between the HG group and the HG+control plasmid-transfected group (all P>0.05). Conclusions Mfn2 down-regulation in HG-stimulated podocytes may induce ERS to increase apoptosis of podocytes. Up-regulation of Mfn2 can alleviate the HG-induced ERS and apoptosis in podocytes.