Integrative profiling of untreated primary membranous nephropathy at the single-cell transcriptome level.

Background: Primary membranous nephropathy (PMN) is an autoimmune kidney disease. Despite the identification of certain autoantigens, the etiology and pathophysiology of PMN are still largely unknown. Methods: Five patients with biopsy-proven PMN were enrolled in this study. Their blood, kidney and urine samples were collected respectively to profile cellular, molecular and immunological alterations by using single-cell RNA sequencing (scRNA-seq). Experimental verifications were also implemented in kidney tissue. Results: In the peripheral blood mononuclear cell (PBMC) samples, portions of B cells and plasma cells were increased in PMN patients. Cell-cell communication analysis suggests that APRIL (a proliferation-inducing ligand from B cells) might be a potential molecule that regulates the activity of plasma cells. In the kidney samples, scRNA-seq analysis showed that the infiltration of T cells, as well as the myeloid cells, appears abundant compared with healthy controls, suggesting that immune cells are actively recruited to kidney. Furthermore, we observed an enhanced interaction between inflammatory cells and podocytes, which might contribute to kidney injury. Accordingly, scRNA-seq analysis of urinary samples is partially reminiscent of the kidney cell landscape, especially T cells and myeloid cells, suggesting monitoring urinary samples is a promising method to monitor PMN development. Additionally, integrative analysis across the blood, kidney and urine identified LTB, HERP1, ANXA1, IL1RN and ICAM1 as common regulators of PMN. Finally, immune repertoire in PBMC also showed an elevated diversity of clonal type, implying the existence of autoreactive T-cell receptor/B-cell receptor. Conclusion: Our study comprehensively profiled the transcriptomic landscapes of blood, kidney and urine in patients with PMN using scRNA-seq. We depicted the alterations including cell compositions and cell-cell communication in PMN. These results offer important clues with regard to the diagnosis and pathogenesis of PMN and potential intervention of PMN progression.

Decreased IgA binding levels were accompanied by increased IgG sialylation in IgA nephropathy.

INTRODUCTION: IgA nephropathy (IgAN) is a kidney disorder characterized by the deposition of circulating immune complexes of IgG bound to galactose-deficient IgA1 (Gd-IgA1) in the mesangial glomeruli. However, limited research has been conducted on the levels of IgA binding in relation to the various sialylation profiles of IgG in IgAN. MATERIALS AND METHODS: Sialylated IgG (SA-IgG) and desialylated IgG (DSA-IgG) were isolated from IgAN patients. The IgG-IgA immune complex (IgG-IgA-IC) was detected using two customized commercial ELISA kits. Additionally, IgG was enzymatically digested with neuraminidase to produce DSA-IgG. Subsequently, the binding capacities of both intact IgG and the neuraminidase-digested DSA-IgG with Gd-IgA1 were determined using ELISA kits. RESULTS: Our research revealed that SA-IgG levels were negatively correlated with Gd-IgA1 (R = -0.16, p = 0.03) in IgAN patients. The optical density (OD) levels of IgG-IgA complexes in SA-IgG samples were significantly lower (0.58 ± 0.09) compared to those in DSA-IgG samples (0.78 ± 0.12) when using the Gd-IgA1 assay kit. These results were confirmed using an IgG assay kit, which showed that the SA-IgG groups had significantly lower IgA indices (0.31 ± 0.12) compared to the DSA-IgG groups (0.57 ± 0.19). Furthermore, we investigated the binding capacity of IgG with different sialic acid levels to Gd-IgA1. The results revealed that neuraminidase digestion of IgG increased its propensity to bind to Gd-IgA1. Additionally, we examined the binding capacity of both intact IgG and DSA-IgG to Gd-IgA1 at different mix ratios (IgG 1.5 µg and Gd-IgA1 1.5 µg, IgG 1.5 µg and Gd-IgA1 3 µg, IgG 3 µg and Gd-IgA1 1.5 µg). Interestingly, DSA-IgG demonstrated significantly higher binding capacity to Gd-IgA1 compared to intact IgG at all mix ratios tested. CONCLUSION: The preliminary findings from our present study indicate that the binding level of IgA in purified sialylated IgG is lower than that in desialylated IgG.

Causal relationship between gut microbiota and Behçet's disease: a Mendelian randomization study.

Background: While observational epidemiological studies have suggested an association between gut microbiota and Behçet's disease (BD), the causal relationship between the two remains uncertain. Methods: Statistical data were obtained from gut microbiome Genome-Wide Association Studies (GWAS) published by the MiBioGen consortium, and genetic variation points were screened as instrumental variables (IV). Mendelian randomization (MR) study was performed using inverse variance weighted (IVW), weighted median, MR-Egger regression, simple mode, and weighted mode methods to evaluate the causal relationship between gut microbiota (18,340 individuals) and BD (317,252 individuals). IVW was the main method of analysis. The stability and reliability of the results were verified using the leave-one-out method, heterogeneity test, and horizontal genetic pleiotropy test. Finally, a reverse MR analysis was performed to explore reverse causality. Results: Inverse variance weighted (IVW) results showed that the genus Parasutterella (OR = 0.203, 95%CI 0.055-0.747, p = 0.016), Lachnospiraceae NC2004 group (OR = 0.101, 95%CI 0.015-0.666, p = 0.017), Turicibacter (OR = 0.043, 95%CI 0.007-0.273, p = 0.001), and Erysipelatoclostridium (OR = 0.194, 95%CI 0.040-0.926, p = 0.040) were protective factors against BD, while Intestinibacter (OR = 7.589, 95%CI 1.340-42.978, p = 0.022) might be a risk factor for BD. Conclusion: Our study revealed the causal relationship between gut microbiota and BD. The microbiota that related to BD may become new biomarkers; provide new potential indicators and targets for the prevention and treatment of BD.

Prognosis of IgA Nephropathy with Stage 3b-5 CKD.

Objective To investigate whether immunosuppressive therapy is beneficial in IgA nephropathy (IgAN) patients with eGFR < 45ml/min/1.73m2. Methods This retrospective study involved 110 IgAN patients for whom clinical data was available; of these, 90 had complete follow-up data. Patients were grouped based on whether they received immunotherapy during follow-up, their renal function, proteinuria levels, and the percentage of crescentic glomeruli observed at the time of renal biopsy. Results The mean eGFR for the participants was 32.0 ± 10.2 ml/min/1.73 m². The average follow-up duration was 46.1 ± 37.9 months. The mean rate of decline in eGFR was 3.6 ml/min/1.73 m² per year. There were 43 (47.8%) composite kidney endpoint occurred in these patients. In the group that received immunotherapy, the incidence of kidney endpoint events was lower than in the untreated group (45.1% vs. 57.9%), but the difference was not statistically significant (P = 0.320). Among patients with stage CKD 3b, the incidence of endpoint events was lower than in those with stages CKD 4 and 5 (36.8% vs. 66.7%, P = 0.006). Conversely, the high proteinuria group saw a higher incidence of endpoint events compared to the low proteinuria group (51.9% vs. 23.1%), although this difference was not statistically significant (P = 0.054). Meanwhile, there was no significant difference in the incidence of endpoint events between the two crescent glomerular ratio groups (48.7% vs. 41.7%, P = 0.649). Kaplan-Meier survival analysis indicated that renal function level (P＜0.001) and proteinuria (P = 0.023) were associated with renal survival in IgAN patients. In contrast, the administration of immunosuppressive therapy (P = 0.288) and the prevalence of C lesions (P = 0.982) did not show a significant association with renal survival. Further, Cox regression analysis identified systolic blood pressure, fibrinogen, and CKD stage as risk factors for eGFR decline in IgAN patients (all P < 0.05). Conclusions IgAN patients with stage 3b-5 CKD exhibited a poor prognosis. It appears that in this specific cohort of IgAN patients, immunosuppressive therapy may not provide significant advantages over supportive care therapeutic regimens in terms of disease management.

Glomerular IgG deposition predicts kidney disease progression in IgA nephropathy.

Objective: We aimed to explore the relationship between the presence and intensity of glomerular IgG deposition and the occurrence of kidney progression events in IgA nephropathy (IgAN). Methods: This retrospective study encompassed a total of 1207 patients with IgAN spanning the period from 2010 to 2022, and complete follow-up data were accessible for 736 patients. The IgG intensity was categorized as follows: low-level, defined as IgG (±) and IgG (+), and high-level, defined as IgG (++) and IgG (+++). Results: We found that the IgG-positive deposited group (N = 113, 9.36%) had significantly higher levels of ESR, TC, LDL, uric acid, proteinuria, and blood glucose, and lower serum albumin level compared to the IgG-negative deposited group (N = 1094, 90.64%). In terms of pathology, the IgG-positive deposited group had a significantly higher percentage of T2 score compared to the IgG-negative deposited group (p = 0.002). At the end of the follow-up period, the IgG-positive deposited group had a higher eGFR decline (-5.7 ± 4.37 ml/year) compared to the IgG-negative deposited group (-4 ± 2.52 ml/year), however, there was not a statistically significant difference between the two groups (p = 0.096). We observed that the high-IgG group had significantly higher level of TG compared to the low-IgG group (p = 0.042). Further analysis revealed that the group of patients with high level of IgG deposition in the kidney experienced a higher incidence of composite kidney outcomes compared to the group with low level of IgG deposition (p = 0.009). Logistic regression analyses showed that high level IgG deposition was an independent risk factor for kidney progression of IgAN (HR 13.419; 95% CI 2.690-66.943, P = 0.029). Further analyses for a solid conclusion using Cox regression that we found high level IgG deposition (HR 115.277; 95% CI 2.299-5.779E3, P = 0.017), eGFR (HR 0.932; 95% CI 0.870-0.999, P = 0.047), and urine protein excretion (HR 1.001; 95% CI 1.000-1.002, P = 0.015) were independent risk factor for kidney progression of IgAN. Conclusions: The intensity of IgG deposition has been found to be associated with the progression of IgAN. Future prospective studies should provide more robust evidence on the impact of IgG deposition on kidney outcomes in patients with IgAN.

Clinical and pathological findings of IgA nephropathy following SARS-CoV-2 infection.

The features of IgA nephropathy (IgAN) after SARS-CoV-2 infection have not been well characterized. In this study, we compared the clinical and pathological characteristics of patients with IgAN who had experienced SARS-CoV-2 infection to those who had not. We conducted a retrospective study that enrolled 38 patients with biopsy-proven IgAN following SARS-CoV-2 infection with 4 months (post-SARS-CoV-2 infection group) and 1154 patients with IgAN prior to the pandemic (pre-SARS-CoV-2 infection group). Among the SARS-CoV-2 group cases, 61% were females. The average duration from SARS-CoV-2 infection to renal biopsy was 78.6 days. Prior to SARS-CoV-2 infection, the patients had different presentations of nephropathy. One patient had isolated hematuria, two had isolated proteinuria, twenty presented with both hematuria and proteinuria, and one patient had elevated serum creatinine. Additionally, there were eight cases with uncertain nephropathy history, and six cases did not have a history of nephropathy. Following SARS-CoV-2 infection, five patients experienced gross hematuria, one case exhibited creatinine elevation, and five cases showed an increase in proteinuria. The group of patients infected with SARS-CoV-2 after the COVID-19 pandemic exhibited older age, higher hypertension ratio and lower eGFR values compared to the pre-SARS-CoV-2 infection group. As for pathological parameters, a higher proportion of patients in the post-SARS-CoV-2 infection group exhibited a higher percentage of sclerotic glomeruli and glomerular ischemic sclerosis. There were no significant differences observed between the two groups in terms of therapy involving steroids, immunosuppressants, or RAS inhibitors. IgA nephropathy patients who were infected with SARS-CoV-2 were generally older and experienced more severe kidney damage compared to those without SARS-CoV-2 infection.

The optimal cut-off values of Klotho for predicting all-cause and cardiovascular mortality among chronic kidney disease: results from NHANES.

To explore the optimal cut-off values of Klotho for predicting all-cause and cardiovascular mortality among chronic kidney disease (CKD) patients. Klotho was measured in 40-79-year-old individuals in the NHANES 2007-2016. A total of 2418 patients with stage 1-4 CKD were included. The optimal cut-off values of Klotho were utilized using receiver operator characteristic (ROC) curves and be verified on the effects of all-cause and cardiovascular mortality. Restricted cubic splines were used to examine the relationship between Klotho and all-cause and cardiovascular mortality with the optimal cutpoints as the reference. After a mean follow-up period of 87.9 months, 535 deaths occurred and 188 died of cardiovascular disease. Cubic splines showed that the risk of all-cause and cardiovascular mortality increased gradually for Klotho < 700 pg/ml. ROC curves revealed that the optimal cut-off values of Klotho for all-cause and cardiovascular mortality are 548.8 pg/ml and 660.9 pg/ml, respectively. Compared to patients with higher levels of Klotho, HRs (95% CIs) for all-cause and cardiovascular mortality were 1.52 (1.23, 1.87) and 1.58 (1.13, 2.22) among patients with lower levels of Klotho, respectively, in the multivariate model (P < .0001 and P = 0.008). Our findings revealed the optimal cut-off values of Klotho for all-cause and cardiovascular mortality in CKD.

The protease inhibitor E64d might attenuate the development of experimental anti-glomerular basement membrane disease through regulating the activation of Th1 cells.

BACKGROUND: Cathepsins have been recently identified as a regulator in the activation of Th1 and Th17 cells, which play an important role in the pathogenesis of anti-glomerular basement membrane (GBM) disease. Whether cathepsins contribute to the development of anti-GBM disease through regulating the activation of CD4+ T cell is still unclear. METHODS: Rats with experimental anti-GBM disease was established by immunization with the nephritogenic T cell epitope α3127-148. E64d, a cysteine cathepsin inhibitor, was administered in vitro and vivo to evaluate the effect of cathepsins on regulating the activation of antigen specific T cells and the development of anti-GBM disease. RESULTS: In rats with experimental anti-GBM diseases, E64d treatment not only reduced the levels of proteinuria, serum creatinine and anti-GBM antibody, but also ameliorated the kidney injury with less glomerular IgG deposition, a lower percentage of crescents and less infiltration of CD4+ T cells, CD8+ T cells and macrophages, as well as a lower percentage of splenic Th1 cells. In vitro, E64d treatment could significantly reduce the production of IFN-γ in the supernatant which might be produced by the activation of Th1 cells after being recalled with the autoantigen α3127-148. We also found the CD4+ T cells of rats with anti-GBM disease had an increased expression of cathepsin L (Cts-L), and the percentage of CD4+ T cells with extracellular expression of Cts-L was obviously higher, indicating it as a potential key regulator. CONCLUSIONS: E64d might attenuate the development of anti-GBM disease by participating in the activation of Th1 cells, indicating it as a potential drug for anti-GBM disease in the future.

The effect of fibrinoid necrosis on the clinical features and outcomes of primary IgA nephropathy.

BACKGROUND: To explore the clinicopathologic features and outcomes of IgAN patients who presented with fibrinoid necrosis (FN) lesions or not and the effect of immunosuppressive (IS) treatment in IgAN patients with FN lesions as well. METHODS: This was a retrospective cohort study with 665 patients diagnosed with primary IgAN from January 2010 to December 2020 in Tianjin Medical University General Hospital and having detailed baseline and follow-up characteristics. Patients were divided into two groups depending on the appearance of FN lesions. Patients with FN lesions were recruited into Group FN1, while patients who were not found FN lesions in their renal biopsy specimens were recruited into Group FN0. Compare the differences between Group FN0 and Group FN1 in baseline clinicopathologic features, treatment solutions and follow-up data as well. To evaluate the impact of different fractions of FN lesions on baseline characteristics and prognosis of IgAN, we subdivided patients in Group FN1 into 3 groups depending on the FN lesions distribution, Mild Group: 0 < FN% < 1/16; Moderate Group: 1/16 < FN% < 1/10; Severe Group: FN% > 1/10. Furthermore, we compared the differences in baseline clinicopathologic features, treatment solutions and follow-up data among these three groups. Kidney endpoint event was defined as patients went into end-stage kidney disease (ESKD), which estimated glomerular filtration rate (eGFR) < 15 ml/min/1.73 m^2, regularly chronic dialysis over 6 months or received renal transplantation surgery. The kidney composite endpoint was defined by a ≥ 30% reduction in eGFR, double Scr increase than on-set, ESKD, chronic dialysis over 6 months or renal transplantation. Compare the survival from a composite endpoint rate in different groups by Kaplan-Meier survival curve. The univariate and multivariate Cox models were used to establish the basic model for renal outcomes in patients with FN lesions. RESULTS: (1) A total of 230 patients (34.59%) were found FN lesions in all participants. Patients with FN lesions suffered more severe hematuria than those without. On the hand of pathological characteristic, patients with FN lesions showed higher proportions of M1, E1, C1/C2 and T1/T2 lesions compared with those without FN lesions. (2) The 1-year, 3-year, and 5-year survival of the composite endpoint were lower in the FN1 group than FN0 group. (3) After adjusting for clinicopathological variables, the presence of FN lesions was a significantly independent risk factor for composite endpoint. By using multivariate Cox regression analyses, we also found when the fraction of FN lesions exceeded 10%, the risk of progression into composite endpoint increased 3.927 times. CONCLUSION: Fibrinoid necrosis of capillary loops is an independent risk factor of poor renal outcomes. More effective treatment should be considered for those who had FN lesions.

Pegmolesatide for the treatment of anemia in patients undergoing dialysis: a randomized clinical trial.

Background: Pegmolesatide, a synthetic peptide-based erythropoietin (EPO) receptor agonist, is being evaluated as an alternative to epoetin alfa for treating anemia of chronic kidney disease (CKD) in Chinese dialysis patients. There is a critical need for a long-acting, cost-effective erythropoiesis-stimulating agent that does not produce EPO antibodies. Methods: A randomized, open-label, active-comparator, non-inferiority phase three trial was conducted at 43 dialysis centers in China between May 17th, 2019, and March 28th, 2022. Eligible patients aged 18-70 years were randomly assigned (2:1) to receive pegmolesatide once every four weeks or epoetin alfa one to three times per week, with doses adjusted to maintain a hemoglobin level between 10.0 and 12.0 g/dL. The primary efficacy endpoint was the mean change in hemoglobin level from baseline to the efficacy evaluation period in the per-protocol set (PPS) population. Non-inferiority of pegmolesatide to epoetin alfa was established if the lower limit of the two-sided 95% confidence interval for the between-group difference was ≥ -1.0 g/dL. Safety assessment included adverse events and potential anaphylaxis reactions. This trial is registered at ClinicalTrials.gov, NCT03902691. Findings: Three hundreds and seventy-two patients were randomly assigned to the pegmolesatide group (248 patients) or the epoetin alfa group (124 patients). A total of 347 patients (233 in the pegmolesatide group and 114 in the epoetin alfa group) were included in the PPS population. In the PPS, the mean change (standard deviation, SD) in hemoglobin level from baseline to the efficacy evaluation period was 0.07 (0.92) g/dL in the pegmolesatide group and -0.22 (0.97) g/dL in the epoetin alfa group. The between-group difference was 0.29 g/dL (95% confidence interval: 0.11-0.47), verifying non-inferiority of pegmolesatide to epoetin alfa. Adverse events occurred in 231 (94%) participants in the pegmolesatide group and in 110 (89%) in the epoetin alfa group. Hypertension was the most common treatment-related adverse event. No fatal cases of anaphylaxis or hypotension were reported. Interpretation: Monthly subcutaneously injection of pegmolesatide was as effective and safe as conventional epoetin alfa administrated one to three times a week in treating anemia in Chinese dialysis patients. Funding: The study was supported by Hansoh Medical Development Group.

Effect of hematuria on the kidney disease progression in IgA nephropathy patients with mild proteinuria and well-preserved renal function.

OBJECTIVE: To investigate whether hematuria is a risk factor in IgA nephropathy (IgAN) patients with mild proteinuria and well-preserved renal function. METHODS: This retrospective study included a total of 63 IgAN patients, with complete clinical data available for 50 patients. Hematuria assessment was conducted using two methods: 1) an automated method using a urine particle analyzer, and 2) a manual method performed by a skilled examiner to examine microscopic urine sediment. RESULTS: The results of hematuria measurement using both automated and manual methods showed a strong linear correlation (r = 0.78, P < 0.001). In IgAN patients, those with high urinary red blood cell count (U-RBCs) exhibited higher serum IgA levels compared to patients with low U-RBCs. Additionally, patients with crescent formation had higher levels of proteinuria compared to those without crescents. Patients who received immunosuppressive treatment displayed higher levels of systolic blood pressure (SBP) and mean arterial pressure (MAP), as well as lower levels of serum hemoglobin and albumin. They also had a higher prevalence of T1 lesions compared to patients who did not undergo immunosuppression. Furthermore, among patients with crescent formation, those who received immunosuppressive agents exhibited higher levels of SBP, diastolic blood pressure (DBP), MAP, and U-RBCs, as well as lower levels of albumin and proteinuria at the time of renal biopsy. No composite kidney endpoint events were observed in these groups of patients. The U-RBCs level was not identified as a risk factor influencing the decline of estimated glomerular filtration rate (eGFR) in IgAN. CONCLUSIONS: The presence of hematuria at the time of biopsy was not found to be associated with kidney disease progression in IgAN patients who had mild proteinuria and well-preserved renal function. This suggests that it is possible that these patients may not derive significant benefits from immunosuppressive therapy.

Deciphering prognostic value of CD22 and its contribution to suppression of proinflammatory cytokines production in patients with IgA nephropathy.

BACKGROUND: CD22, mainly expressed in mature B cells, could negatively regulate the function of B cells by binding to sialic acid-positive IgG (SA-IgG). Soluble CD22 (sCD22) is generated by the cleavage of the extracellular domain of CD22 on the membrane surface. However, the role of CD22 in IgA nephropathy (IgAN) remains unknown. METHODS: A total of 170 IgAN patients with a mean follow-up of 18 months were included in this study. The sCD22, TGF-ß, IL-6 and TNF-α were detected using commercial ELISA kits. SA-IgG were purified to stimulate peripheral blood mononuclear cells (PBMCs) from IgAN patients. RESULTS: The plasma levels of sCD22 were lower in IgAN patients in comparison with healthy control. Furthermore, CD22 mRNA levels in PBMCs from patients with IgAN were significantly lower than those of healthy controls. The plasma levels of sCD22 were positively correlated to the mRNA levels of CD22. We found that patients with higher sCD22 levels had a lower level of serum creatinine and a higher level of eGFR on the time of renal biopsy and a higher remission rate of proteinuria and a lower risk of kidney events at the end of follow-up. The logistic regression analysis showed sCD22 was associated with an increased odd of proteinuria remission after being adjusted for eGFR, proteinuria, and SBP. After adjusting for confounding variables, sCD22 was a borderline significant predictor of less kidney composite endpoint. In addition, the sCD22 levels were positively associated with SA-IgG in plasma. The experimental results in vitro showed that addition of SA-IgG enhanced the release of sCD22 in cell supernatant and the phosphorylation of CD22 in PBMCs, further inhibiting the production of IL-6, TNF-α, and TGF-ß in cell supernatant in a dose-dependent manner. Pretreatment with CD22-antibody significantly increased the expression of cytokines in PBMCs. CONCLUSIONS: This is the first study to demonstrate that lower plasma soluble CD22 in IgAN patients and high soluble CD22 levels are associated with an increased odd of proteinuria remission and a decreased odd of kidney endpoint. The interaction between CD22 and SA-IgG can inhibit proliferation and inflammation release in PBMCs from IgAN patients.

Circulating platelets supply ST6Gal-1 in patients with IgA nephropathy.

BACKGROUND: Our previous study showed ST6 ß-galactoside α2,6-sialyltransferase 1 (ST6Gal-1) levels in plasma were associated with a slower progression of IgA nephropathy (IgAN). Platelets are the crucial regulator of cell surface glycosylation events in circulation by supplying glycosyltransferases. METHODS: A total of 180 patients with IgAN were included in this study. ST6Gal-1 levels were analyzed before and after activation of platelets by flow cytometry. RESULTS: We found that IgAN patients in the higher platelet counts group exhibited higher levels of ST6Gal-1 compared with the lower platelet counts group. There was a positive correlation between platelet counts and ST6Gal-1 levels in plasma. Patients with higher platelet counts had higher levels of IgA, serum C3, serum C4 and proteinuria, higher percentages of platelet crits, S1 and T1/2, lower levels of platelet distribution width and the mean platelet volume, as well as a lower percentage of platelet large cell ratio compared with those patients with lower platelet counts. No differences were found in terms of the eGFR decline and composite kidney endpoints between two groups. Furthermore, we investigated whether platelets were activated and released ST6Gal-1 in patients with IgAN. The expression of CD62P in platelets in patients with IgAN was higher than those of healthy controls. There were no obvious changes in ST6Gal-1 levels between the rest and the activated platelets within 1 to 2-hour, however, the difference in ST6Gal-1 levels became more pronounced after 4-hour of incubation. CONCLUSIONS: In conclusion, human circulating platelets contain ST6Gal-1, which may be released by the activation of platelets in IgAN.

What is the context? Our previous study showed ST6 ß-galactoside α2,6-sialyltransferase 1 (ST6Gal-1) levels in plasma were associated with a slower progression of IgA nephropathy (IgAN).Platelets are the crucial regulator of cell surface glycosylation events in circulation by supplying glycosyltransferases.Whether elevated ST6Gal-1 in plasma is partly from platelets in IgAN has not been fully elucidated.What is new? A total of 180 patients with IgAN were included in this study.We found that IgAN patients in the higher platelet counts group exhibited higher levels of ST6Gal-1 compared with the lower platelet counts group.Patients with higher platelet counts had higher levels of IgA, serum C3, serum C4 and proteinuria, higher percentages of platelet crits, S1 and T1/2, lower levels of platelet distribution width and the mean platelet volume, as well as a lower percentage of platelet large cell ratio.There were no differences in terms of the eGFR decline and composite kidney endpoints between two groups.Furthermore, we explored whether platelets were activated and released ST6Gal-1 in patients with IgAN. The expression of CD62P in platelets in patients with IgAN was higher than that of healthy controls.There were no obvious changes in ST6Gal-1 levels between the rest and the activated platelets within 1 to 2-hour, however, the difference in ST6Gal-1 levels became more pronounced after 4-hour of incubation.What is the impact?Human circulating platelets contain ST6Gal-1, which can be released upon platelets activation. These findings suggest ST6Gal-1 is dynamically controlled by platelet activation to remodel cell surface glycans and alter cell behavior.

Effects of febuxostat on delaying chronic kidney disease progression: a randomized trial in China.

BACKGROUND: A few studies have tested febuxostat for its usefulness in delaying chronic kidney disease (CKD) progression by treating hyperuricemia and results were controversial. Thus, we attempted to conduct a randomized controlled study using the Chinese population with advanced grade of CKD. METHODS: One hundred CKD patients in stages 3 and 4 with asymptomatic hyperuricemia from seven medical centers were included in this prospective randomized controlled study and assigned to the control and febuxostat group, the latter of which received febuxostat to titrate to achieve serum uric acid (SUA) < 6 mg/dL. The observation period was 12 months. The primary outcomes included the event of estimated glomerular filtration rate (eGFR) decline ≥ 30% or 50% from baseline at 12 months, dialysis and death from CKD; secondary outcome was the change in eGFR. Safety analysis was also performed. RESULTS: Forty-seven patients and 45 patients in the febuxostat and control groups, respectively completed the study. Seven of 47 (14.9%) participants reached 30% decline in eGFR in the febuxostat group, while 1 (2.1%) and 2 (4.3%) patients reached 50% decline in eGFR or dialysis. Thirteen (28.9%), 10 (22.2%) and 3 (6.7%) of 45 patients reached primary kidney outcomes separately in the control group. The change in eGFR after 12 months from baseline in the febuxostat group was 0.50 mL/min/1.73 m2, which was significantly higher than that in the control group - 4.46 mL/min/1.73 m2 (p = 0.006). Adverse events did not differ between two groups. CONCLUSIONS: Febuxostat effectively slowed eGFR decline in patients with CKD stages 3 and 4 and asymptomatic hyperuricemia.

Effects of sodium-glucose co-transporter-2 inhibitors on kidney, cardiovascular, and safety outcomes in patients with advanced chronic kidney disease: a systematic review and meta-analysis of randomized controlled trials.

AIMS: The overall effects of sodium-glucose co-transporter 2 (SGLT2) inhibitors in patients with advanced chronic kidney disease (CKD) (estimated glomerular filtration rate (eGFR), 15-30 ml/min per 1.73 m2) remain unclear, and we thus conducted a systematic review and meta-analysis to evaluate the effects of SGLT2 inhibitors on kidney, cardiovascular (CV), and safety outcomes in patients with advanced CKD. METHODS: The Medline, Embase, and Cochrane Library databases were systematically searched for randomized controlled trials (RCTs) published up to March 3, 2022, and reporting effects of SGLT2 inhibitors on kidney, CV, or safety outcomes in patients with advanced CKD. RESULTS: From 2675 records, six RCTs with 2167 participants were included in the quantitative analyses. In patients with advanced CKD, SGLT2 inhibitors reduced the risk of the primary kidney outcome (a composite of worsening kidney function, end-stage kidney disease (ESKD), or kidney death) by 23% (RR 0.77, 95% CI 0.61-0.98, p = 0.04, I2 = 0 for the heterogeneity) and slowed the annual decline in eGFR slope, with the difference between SGLT2 inhibitor group and placebo group being 1.24 mL/min/1.73m2 per year (95% CI 0.06-2.42, p = 0.04). SGLT2 inhibitors were also associated with a decreased risk of primary CV outcome (a composite of CV death or hospitalization for heart failure) (HR 0.71, 95% CI 0.53-0.96, p = 0.03, I2 = 0 for the heterogeneity) and with similar risks of adverse events (such as acute kidney injury, fracture, amputation, and urinary tract infection). CONCLUSIONS: Among patients with advanced CKD, SGLT2 inhibitors reduced the risks of primary kidney and CV outcomes and attenuated the progressive decrease in eGFR compared with placebo, with no evidence of additional safety concerns. These observed benefits may support continuing the use of SGLT2 inhibitors in patients with advanced CKD before initiating maintenance dialysis or kidney transplantation. Future large-scale RCTs are needed to confirm the robustness of these results.

Significance of thyroid dysfunction in the patients with primary membranous nephropathy.

BACKGROUND: Thyroid dysfunction is common in patients with nephrotic syndrome, especially patients with primary membranous nephropathy (pMN). In view of both MN and thyroid dysfunction are associated with autoimmunity, the current study aimed to elucidate the significance of thyroid dysfunction in patients with pMN. METHODS: Four hundred and twenty patients with biopsy-proven pMN from 2018-2021 were retrospectively enrolled. Clinical and pathological parameters, and treatment response of patients with and without thyroid dysfunction were analyzed. RESULTS: Ninety-one (21.7%) patients with pMN suffered from thyroid dysfunction, among which subclinical hypothyroidism (52.7%) was the main disorder. Compared to patients with normal thyroid function, patients with thyroid dysfunction presented with a higher level of proteinuria, a lower level of serum albumin, a higher level of serum creatinine and more severe tubulointerstitial injury at the time of biopsy. But the positive rate and level of circulating anti-phospholipase A2 receptor (PLA2R) antibody were comparable between these two groups. Though following the similar treatment, the percentage of no response to treatment were significantly higher in the patients with thyroid dysfunction (38.6 vs. 20.0%, P = 0.003). Similar to the urinary protein and the positivity of anti-PLA2R antibody, multivariate COX analysis showed thyroid dysfunction was also identified as an independent risk factor for the failure to remission (HR = 1.91, 95%CI, 1.07-3.40, P = 0.029). CONCLUSION: In conclusion, thyroid dysfunction is common in the patients with pMN and might predict a severe clinical manifestation and a poor clinical outcome, which indicated that the thyroid dysfunction might be involved in the disease progression of pMN.

Identification of tubulointerstitial genes and ceRNA networks involved in diabetic nephropathy via integrated bioinformatics approaches.

BACKGROUND: Diabetic nephropathy (DN) is the major cause of end-stage renal disease worldwide. The mechanism of tubulointerstitial lesions in DN is not fully elucidated. This article aims to identify novel genes and clarify the molecular mechanisms for the progression of DN through integrated bioinformatics approaches. METHOD: We downloaded microarray datasets from Gene Expression Omnibus (GEO) database and identified the differentially expressed genes (DEGs). Enrichment analyses, construction of Protein-protein interaction (PPI) network, and visualization of the co-expressed network between mRNAs and microRNAs (miRNAs) were performed. Additionally, we validated the expression of hub genes and analyzed the Receiver Operating Characteristic (ROC) curve in another GEO dataset. Clinical analysis and ceRNA networks were further analyzed. RESULTS: Totally 463 DEGs were identified, and enrichment analyses demonstrated that extracellular matrix structural constituents, regulation of immune effector process, positive regulation of cytokine production, phagosome, and complement and coagulation cascades were the major enriched pathways in DN. Three hub genes (CD53, CSF2RB, and LAPTM5) were obtained, and their expression levels were validated by GEO datasets. Pearson analysis showed that these genes were negatively correlated with the glomerular filtration rate (GFR). After literature searching, the ceRNA networks among circRNAs/IncRNAs, miRNAs, and mRNAs were constructed. The predicted RNA pathway of NEAT1/XIST-hsa-miR-155-5p/hsa-miR-486-5p-CSF2RB provides an important perspective and insights into the molecular mechanism of DN. CONCLUSION: In conclusion, we identified three genes, namely CD53, CSF2RB, and LAPTM5, as hub genes of tubulointerstitial lesions in DN. They may be closely related to the pathogenesis of DN and the predicted RNA regulatory pathway of NEAT1/XIST-hsa-miR-155-5p/hsa-miR-486-5p-CSF2RB presents a biomarker axis to the occurrence and development of DN.

Exploring the pathogenesis of diabetic kidney disease by microarray data analysis.

Diabetic kidney disease (DKD) is a major complication of diabetes mellitus, and the leading contributor of end-stage renal disease. Hence, insights into the molecular pathogenesis of DKD are urgently needed. The purpose of this article is to reveal the molecular mechanisms underlying the pathogenesis of DKD. The microarray datasets of GSE30528 and GSE30529 were downloaded from the NCBI Gene Expression Omnibus (GEO) database to identify the common differentially expressed genes (DEGs) between the glomerular DKD (GDKD) and tubular DKD (TDKD), respectively. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed to analyze the function and pathways of the common DEGs. After constructing the protein-protein interaction (PPI) network and subnetwork analysis, three types of analyses were performed, namely, identification of hub genes, analysis of the coexpressed network, and exploration of transcription factors (TFs). Totally, 348 and 463 DEGs were identified in GDKD and TDKD, respectively. Then, 66 common DEGs (63 upregulated DEGs and three downregulated DEGs) were obtained in DKD patients. GO and KEGG pathway analyses revealed the importance of inflammation response, immune-related pathways, and extracellular matrix-related pathways, especially chemokines and cytokines, in DKD. Fifteen hub genes from the 66 common DEGs, namely, IL10RA, IRF8, LY86, C1QA, C1QB, CD53, CD1C, CTSS, CCR2, CD163, CCL5, CD48, RNASE6, CD52, and CD2 were identified. In summary, through the microarray data analysis, the common functions and hub genes greatly contribute to the elucidation of the molecular pathogenesis associated with DKD.

The potential pathogenic roles of S100A8/A9 and S100A12 in patients with MPO-ANCA-positive vasculitis.

BACKGROUND: The significance of S100A8/A9 and S100A12 in anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) has not been clarified. This study was dedicated to exploring the potential pathogenic roles of S100A8/A9 and S100A12 in patients with myeloperoxidase (MPO)-ANCA-positive vasculitis. METHODS: Serum and urine concentrations of S100A8/A9 and S100A12 of forty-two AAV patients were evaluated. The influence of S100A8/A9 and S100A12 on the chemotaxis, the apoptosis, the release of IL-1ß, the complement activation, the respiratory burst, as well as the neutrophil extracellular traps (NETs) formation of MPO-ANCA-activated neutrophils was investigated. RESULTS: The serum and urine S100A8/A9 and S100A12 of active MPO-AAV significantly increased (compared with inactive AAV and healthy controls, p < 0.001) and were correlated with the severity of the disease. In vitro study showed that S100A8/A9 and S100A12 activated the p38 MAPK/NF-κB p65 pathway, increased the chemotaxis index (CI) and the release of IL-1ß, extended the life span, and enhanced the complement activation ability of MPO-ANCA-activated neutrophils. The Blockade of TLR4 and RAGE inhibited the effects of S100A8/A9 and S100A12. All above-mentioned effects of S100A8/A9 and S100A12 were ROS-independent because neither S100A8/A9 nor S100A12 enhanced the ROS formation and NETs formation of MPO-ANCA-activated neutrophils. CONCLUSION: S100A8/A9 and S100A12 serve as markers for assessing the disease severity, and they may also play a role in MPO-AAV pathogenesis.

Associations between short-term exposure of ambient particulate matter and hemodialysis patients death: A nationwide, longitudinal case-control study in China.

BACKGROUND: Long-term exposure to particulate air pollutants can lead to an increase in mortality of hemodialysis patients, but evidence of mortality risk with short-term exposure to ambient particulate matter is lacking. This study aimed to estimate the association of short-term exposure to ambient particulate matter across a wide range of concentrations with hemodialysis patients mortality. METHODS: We performed a time-stratified case-crossover study to estimate the association between short-term exposures to PM2.5 and PM10 and mortality of hemodialysis patients. The study included 18,114 hemodialysis death case from 279 hospitals in 41 cities since 2013. Daily particulate matter exposures were calculated by the inverse distance-weighted model based on each case's dialysis center address. Conditional logistic regression were implemented to quantify exposure-response associations. The sensitivity analysis mainly explored the lag effect of particulate matter. RESULTS: During the study period, there were 18,114 case days and 61,726 control days. Of all case and control days, average PM2.5 and PM10 levels were 43.98 µg/m3 and 70.86 µg/m3, respectively. Each short-term increase of 10 µg/m3 in PM2.5 and PM10 were statistically significantly associated with a relative increase of 1.07 % (95 % confidence interval [CI]: 0.99 % - 1.15 %) and 0.89 % (95 % CI: 0.84 % - 0.94 %) in daily mortality rate of hemodialysis patients, respectively. There was no evidence of a threshold in the exposure-response relationship. The mean of daily exposure on the same day of death and one-day prior (Lag 01 Day) was the most plausible exposure time window. CONCLUSIONS: This study confirms that short-term exposure to particulate matter leads to increased mortality in hemodialysis patients. Policy makers and public health practices have a clear and urgent opportunity to pass air quality control policies that care for hemodialysis populations and incorporate air quality into the daily medical management of hemodialysis patients.