A promising application of kidney-specific cell-free DNA methylation markers in real-time monitoring sepsis-induced acute kidney injury.

Sepsis-induced acute kidney injury (SI-AKI) is a common clinical syndrome that is associated with high mortality and morbidity. Effective timely detection may improve the outcome of SI-AKI. Kidney-derived cell-free DNA (cfDNA) may provide new insight into understanding and identifying SI-AKI. Plasma cfDNA from 82 healthy individuals, 7 patients with sepsis non-acute kidney injury (SN-AKI), and 9 patients with SI-AKI was subjected to genomic methylation sequencing. We deconstructed the relative contribution of cfDNA from different cell types based on cell-specific methylation markers and focused on exploring the association between kidney-derived cfDNA and SI-AKI.Based on the deconvolution of the cfDNA methylome: SI-AKI patients displayed the elevated cfDNA concentrations with an increased contribution of kidney epithelial cells (kidney-Ep) DNA; kidney-Ep derived cfDNA achieved high accuracy in distinguishing SI-AKI from SN-AKI (AUC = 0.92, 95% CI 0.7801-1); the higher kidney-ep cfDNA concentrations tended to correlate with more advanced stages of SI-AKI; strikingly, SN-AKI patients with potential kidney damage unmet by SI-AKI criteria showed higher levels of kidney-Ep derived cfDNA than healthy individuals. The autonomous screening of kidney-Ep (n = 24) and kidney endothelial (kidney-Endo, n = 12) specific methylation markers indicated the unique identity of kidney-Ep/kidney-Endo compared with other cell types, and its targeted assessment reproduced the main findings of the deconvolution of the cfDNA methylome. Our study first demonstrates that kidney-Ep- and kidney-Endo-specific methylation markers can serve as a novel marker for SI-AKI emergence, supporting further exploration of the utility of kidney-specific cfDNA methylation markers in the study of SI-AKI.

Renal Health Through Medicine-Food Homology: A Comprehensive Review of Botanical Micronutrients and Their Mechanisms.

BACKGROUND: As an ancient concept and practice, "food as medicine" or "medicine-food homology" is receiving more and more attention these days. It is a tradition in many regions to intake medicinal herbal food for potential health benefits to various organs and systems including the kidney. Kidney diseases usually lack targeted therapy and face irreversible loss of function, leading to dialysis dependence. As the most important organ for endogenous metabolite and exogenous nutrient excretion, the status of the kidney could be closely related to daily diet. Therefore, medicinal herbal food rich in antioxidative, anti-inflammation micronutrients are ideal supplements for kidney protection. Recent studies have also discovered its impact on the "gut-kidney" axis. METHODS: Here, we review and highlight the kidney-protective effects of botanicals with medicine-food homology including the most frequently used Astragalus membranaceus and Angelica sinensis (Oliv.) Diels, concerning their micronutrients and mechanism, offering a basis and perspective for utilizing and exploring the key substances in medicinal herbal food to protect the kidney. RESULTS: The index for medicine-food homology in China contains mostly botanicals while many of them are also consumed by people in other regions. Micronutrients including flavonoids, polysaccharides and others present powerful activities towards renal diseases. CONCLUSIONS: Botanicals with medicine-food homology are widely speeded over multiple regions and incorporating these natural compounds into dietary habits or as supplements shows promising future for renal health.

Association between Dietary Acid Load and Chronic Kidney Disease in the Chinese Population: A Comprehensive Analysis of the China Health and Nutrition Survey (2009).

BACKGROUND: Dietary acid load (DAL) is closely related to several chronic diseases. However, the link between DAL and chronic kidney disease (CKD) remains scarce and without data from the Chinese populations whose diet is quite different from people in Western countries. METHODS: This study evaluated DAL by potential renal acid load (PRAL) and net endogenous acid production (NEAP). We clarified the relationship between DAL and CKD by logistic regression analysis based on data from the China Health and Nutrition Survey (CHNS). RESULTS: The final analysis included 7699 individuals, of whom 811 (11.44%) were CKD patients. Although there was no notable link between PRAL and CKD, higher NEAP levels were independently correlated with CKD. As NEAP values rise, so does CKD prevalence. This trend remains highly significant even after adjustments. In subgroup analyses, the relationship between NEAP and CKD was more consistent in the elderly and subjects with a waistline of less than 82 cm and those without diabetes and heart disease. RCS analysis further confirmed the clear linear relationship between the OR of CKD and NEAP score. CONCLUSIONS: This study highlighted that higher NEAP was positively correlated with the risk of CKD.

From Rare Disorders of Kidney Tubules to Acute Renal Injury: Progress and Prospective.

Background: Acute kidney injury (AKI) is a severe condition marked by rapid renal function deterioration and elevated mortality, with traditional biomarkers lacking sensitivity and specificity. Rare tubulointerstitial diseases encompass a spectrum of disorders, primarily including monogenic diseases, immune-related conditions, and drug-induced tubulointerstitial diseases. The clinical manifestations vary from electrolyte and acid-base imbalances to kidney function insufficiency, which is associated with AKI in up to 20% of cases. Evidence indicated that rare tubulointerstitial diseases might provide new conceptual insights and perspectives for novel biomarkers and potential therapeutic strategies for AKI. Summary: Autosomal dominant tubulointerstitial kidney disease (ADTKD) and Fanconi syndrome (FS) are rare tubulointerstitial diseases. In ADTKD, UMOD and REN are closely related to AKI by affecting oxidative stress and tubuloglomerular feedback, which provide potential new biomarkers for AKI. Both rare tubulointerstitial diseases and AKI share etiologies and treatment responses. From the mechanism standpoint, rare tubulointerstitial diseases and AKI involve tubular transporter injury, initially manifesting as tubular dysfunction in tubulointerstitial disorder and progressing to AKI because of the programmed cell death with apoptosis, pyroptosis, or necroptosis of proximal tubule cells. Additionally, mitochondrial dysfunction has been identified as a common mechanism in both tubulointerstitial diseases and AKI induced by drugs, pSS, or monoclonal diseases. In the end, both AKI and FS patients and animal models responded well to the therapy of the primary diseases. Key Messages: In this review, we describe an overview of ADTKD and FS to identify their associations with AKI. Mitochondrial dysfunction contributes to rare tubulointerstitial diseases and AKI, which might provide a potential therapeutic target.

Renal damage and old age: risk factors for thrombosis in patients with ANCA-associated vasculitis.

INTRODUCTION: Thrombosis in ANCA-associated vasculitis (AAV) was prevalent and has been neglected in Chinese patients. This study tried to describe the clinical characteristics, identify the risk factors, and investigate the causal relationship between AAV and venous thromboembolism (VTE) by two-sample Mendelian randomization (MR) analysis. METHODS: In this retrospective, observational study, we included all hospitalized AAV patients from Jan 2013 to Apr 2022 in Peking Union Medical College Hospital. We collected their clinical data for multivariate regression analysis to determine the risk factors for thrombosis. The nomogram was constructed by applying these risk factors to predict thrombosis in AAV patients. As for MR analysis, we selected single nucleotide polymorphisms (SNPs) related to AAV from published genome-wide association studies and extracted the outcome data containing deep vein thrombosis (DVT) and pulmonary embolism (PE) from the UK biobank. RESULTS: 1203 primary AAV patients were enrolled, and thrombosis occurred in 11.3%. Multivariate regression suggested that older than 65 years, EGPA, neurological involvement, lung involvement, significantly elevated serum creatinine (> 500µmol/L), and elevated D-dimer were associated with thrombosis in AAV patients. The model demonstrated satisfied discrimination with an AUC of 0.769 (95% CI, 0.726-0.812). MR analysis showed that EGPA could increase the risk of developing DVT and PE (OR = 1.0038, 95%CI = 1.0035-1.0041, P = 0.009). CONCLUSION: Thrombosis was not rare in Chinese patients with AAV. Renal damage and old age emerged as critical risk factors for thrombosis. EGPA might have a potential causal relationship with DVT and PE.

Pure Red Cell Aplasia Secondary to Parvovirus B19 Infection as a Rare Cause of Anemia in a Dialysis Patient.

Parvovirus B19 infection can cause chronic pure red cell aplasia in immunosuppressed hosts or acute and transient aplastic crisis in immunocompetent hosts. In dialysis patients, only transient aplastic crisis induced by parvovirus B19 infection has been reported. We herein report the first case of an adult dialysis patient who developed chronic pure red cell aplasia associated with parvovirus B19 infection. Repeated pneumonia and heart failure may contribute to an immunocompromised status, making the patient more vulnerable to parvovirus B19 infection. This case expands on the differential diagnosis of chronic anemia in patients undergoing dialysis.

New-onset metabolic syndrome is associated with accelerated renal function decline partially through elevated uric acid: an epidemiological cohort study.

Background: The burden of metabolic syndrome (MetS) continues to rise globally and is associated with complications of multiple organ systems. We aimed to identify the association between changes in MetS status and accelerated renal function progression through a regional epidemiological survey in China, thus discovering influence factors with treatable potential. Methods: This study was a population-based survey conducted in 2008 and 2014, assessing a representative sample of 5,225 individuals from rural areas of China. They were divided into four subgroups according to their MetS status in 2008 and 2014 (Never, Previously abnormal, New-onset, and Consistent). Multivariate logistic regression and stratification analysis evaluated the relationship between clinical factors and renal function decline under different MetS statuses. Smooth curve fitting further addressed the role of serum uric acid, illustrating the vital turning point of uric acid levels in the background of renal function deterioration. Results: Of all groups of MetS states, the new-onset MetS showed the most significant eGFR decline, with a 6.66 ± 8.21 mL/min/1.73 m2 decrease over 6 years. The population with newly-onset MetS showed a considerable risk increase in delta eGFR with a beta coefficient of 1.66 (95%CI=1.09-2.23) after necessary correction. In searching for the drivers, the strength of the association was significantly reduced after additional adjustment for uric acid levels (ß=0.91, 95%CI=0.35-1.45). Regarding the turning point, uric acid levels exceeding 426 µmol/L were more significantly associated with the stepped-up deterioration of kidney function for those with new-onset MetS. Conclusion: Metabolic syndrome demonstrated a solid correlation with the progression of renal function, particularly in those with newly-onset MetS status. In addition to the diagnostic components of MetS, hyperuricemia could be used as a marker to identify the high risk of accelerating eGFR decline early. Furthermore, we suggested a potential renal benefit for the newly-onset MetS population when maintaining their serum uric acid level below the criteria for asymptomatic hyperuricemia.

Clinical significance of peripheral T-cell receptor repertoire profiling and individualized nomograms in patients with gastrointestinal cancer treated with anti-programmed death 1 antibody.

Background: Immune checkpoint inhibitors (ICIs) have significant clinical benefit for a subset of patients with gastrointestinal cancers (GICs) including esophageal cancer, gastric cancer and colorectal cancer. However, it is difficult to predict which patients will respond favorably to immune checkpoint blockade therapy. Thus, this study was initiated to determine if peripheral T-cell receptor (TCR) repertoire profiling could predict the clinical efficacy of anti-programmed death 1 (PD-1) treatment. Methods: Blood samples from 31 patients with GICs were collected before anti-PD-1 antibody treatment initiation. The clinical significance of the combinatorial diversity evenness of the TCR repertoire [the diversity evenness 50 (DE50), with high values corresponding to less clonality and higher TCR diversity] from peripheral blood mononuclear cells (PBMCs) was evaluated in all the enrolled patients. A highly predictive nomogram was set up based on peripheral TCR repertoire profiling. The performance of the nomogram was assessed by receiver operating characteristic (ROC) curve, concordance index (C-index), and calibration curves, and decision curve analysis (DCA) was used to assess its clinical applicability. Results: Compared to non-responders [progression disease (PD)], the DE50 scores were significantly higher in responders [stable disease (SD) and partial response (PR)] (P=0.018). Patients with a high DE50 score showed better progression-free survival (PFS) than those with a low DE50 score (P=0.0022). The multivariable Cox regression demonstrated that high DE50 and low platelet-lymphocyte ratio (PLR) were significant independent predictors for better PFS when treated with anti-PD-1 antibody. Furthermore, a highly predictive nomogram was set up based on peripheral TCR repertoire profiling. The area under the curves (AUCs) of this system at 3-, 6- and 12-month PFS reached 0.825, 0.802, and 0.954, respectively. The nomogram had a C-index of 0.768 [95% confidence interval (CI): 0.658-0.879]. Meanwhile, the calibration curves also demonstrated the reliability and stability of the model. Conclusions: High DE50 scores were predictive of a favorable response and longer PFS to anti-PD-1 treatment in GIC patients. The nomogram based on TCR repertoire profiling was a reliable and practical tool, which could provide risk assessment and clinical decision-making for individualized treatment of patients.

Genetic and clinical characterization of familial renal glucosuria.

Background: Familial renal glucosuria (FRG) is a hereditary disorder caused by variants in SLC5A2 encoding sodium-glucose cotransporter 2 (SGLT2). In this study, we aimed to characterize proximal tubule solute transport, glucagon secretion and the genotype-phenotype relationship in FRG patients. Methods: We sequenced SLC5A2 and PDZK1IP1 in 21 FRG patients and measured the renal threshold of glucose (RTG) in 15 patients. We built an open-source online calculator of RTG, evaluated the proximal tubule transport of amino acid, uric acid and phosphate, and explored glucagon secretion after glucose ingestion in FRG patients. Results: We identified 12 novel SLC5A2 variants (G484D, R564W, A212S, c.574+1G>C, W649*, S592Cfs*6, Q579*, Y339*, V39F, G491E, A464E and G360D) in our cohort and yielded 111 SLC5A2 variants from literature review. RTG in our cohort ranged from 1.0 to 9.2 mmol/L. Patients with two SLC5A2 variants had lower RTG (3.9 vs 6.2 mmol/L) and higher 24-h urinary glucose excretion (24hUG) than single-variant carriers (291.0 vs 40.0 mmol/1.73 m2). Patients with homozygous missense or in-frame indels had mean 24hUG of 457.2 mmol/1.73 m2, comparable to those with homozygous truncating variants (445.0 mmol/1.73 m2) and significantly more than those with homozygous splicing variants (196.6 mmol/1.73 m2). Patients with homozygous missense variants involving conservative residues (582.0 mmol/1.73 m2) had more 24hUG than those with variants at non-conservative residues (257.6 mmol/1.73 m2). Four out of 14 tested patients had mild aminoaciduria. The RTG of FRG patients had no significant correlation to phosphate reabsorption but a potential negative correlation to the fractional excretion of uric acid. Postprandial suppression of glucagon secretion was absent in most FRG patients. Conclusions: We built a comprehensive map showing the impact of SLC5A2 variant type and variant location on glucosuria severity. Our results highlighted the role of key residues in maintaining the transport function of SGLT2 and the functional link between glucosuria and reabsorption of amino acid and uric acid in FRG patients.

Corrigendum to "End Stage Renal Failure Patients With Hemophilia Treated With Peritoneal Dialysis: A Case Series" [Kidney International Reports Volume 7, Issue 12, December 2022, Pages 2639-2646].

[This corrects the article DOI: 10.1016/j.ekir.2022.09.030.].

Rare renal proximal tubular dysfunctions in primary biliary cholangitis.

INTRODUCTION: Renal involvement of primary biliary cholangitis (PBC) usually presents as distal renal tubular acidosis. Proximal tubular (PT) dysfunctions in PBC were rarely reported with unclear clinicopathological characteristics and renal prognosis. METHODS: We identified 11 cases of PBC with PT dysfunctions (PBC-PT). Their medical document, kidney pathology, and follow-up data were retrospectively reviewed and analyzed. RESULTS: The 11 PBC-PT patients were mainly middle-aged (57.8 ± 5.2 years) females (81.8%). Most of them were asymptomatic PBC (7, 63.6%) with a high prevalence of elevated serum immunoglobulin M (IgM, 81.8%) and G (IgG, 54.5%) levels. In the kidney, they had a mean estimated glomerular filtration rate (eGFR) level of 46.54 ± 23.03 ml/min/1.73m2, and 81.8% of them had eGFR below 60 ml/min/1.73m2. They showed different degrees of PT dysfunctions, including hyperuricosuria, hypouricemia, normoglycemic glycosuria, generalized aminoaciduria, hyperphosphaturia, and hypophosphatemia. Their kidney pathology showed tubulointerstitial nephritis with lymphoplasmacytic infiltrates, brush border defects, and proximal tubulitis. After glucocorticoids treatment, the PT dysfunctions manifesting as hypophosphatemia, hypouricemia, and renal glycosuria all recovered, and the eGFR levels were improved from 43.24 ± 19.60 ml/min/1.73m2 to 55.02 ± 21.14 ml/min/1.73m2 (p = 0.028), accompanied by significant improvements of serum IgM levels (from 5.97 ± 4.55 g/L to 2.09 ± 1.48 g/L, p = 0.019). CONCLUSIONS: The PT dysfunctions were rare in PBC patients, and glucocorticoids treatment could benefit the improvements of eGFR and tubular functions.

Integrated multi-omics profiling to dissect the spatiotemporal evolution of metastatic hepatocellular carcinoma.

Comprehensive molecular analyses of metastatic hepatocellular carcinoma (HCC) are lacking. Here, we generate multi-omic profiling of 257 primary and 176 metastatic regions from 182 HCC patients. Primary tumors rich in hypoxia signatures facilitated polyclonal dissemination. Genomic divergence between primary and metastatic HCC is high, and early dissemination is prevalent. The remarkable neoantigen intratumor heterogeneity observed in metastases is associated with decreased T cell reactivity, resulting from disruptions to neoantigen presentation. We identify somatic copy number alterations as highly selected events driving metastasis. Subclones without Wnt mutations show a stronger selective advantage for metastasis than those with Wnt mutations and are characterized by a microenvironment rich in activated fibroblasts favoring a pro-metastatic phenotype. Finally, metastases without Wnt mutations exhibit higher enrichment of immunosuppressive B cells that mediate terminal exhaustion of CD8+ T cells via HLA-E:CD94-NKG2A checkpoint axis. Collectively, our results provide a multi-dimensional dissection of the complex evolutionary process of metastasis.

Development of a multiple convolutional neural network-facilitated diagnostic screening program for immunofluorescence images of IgA nephropathy and idiopathic membranous nephropathy.

Background: Immunoglobulin A nephropathy (IgAN) and idiopathic membranous nephropathy (IMN) are the most common glomerular diseases. Immunofluorescence (IF) tests of renal tissues are crucial for the diagnosis. We developed a multiple convolutional neural network (CNN)-facilitated diagnostic program to assist the IF diagnosis of IgAN and IMN. Methods: The diagnostic program consisted of four parts: a CNN trained as a glomeruli detection module, an IF intensity comparator, dual-CNN (D-CNN) trained as a deposition appearance and location classifier and a post-processing module. A total of 1573 glomerular IF images from 1009 patients with glomerular diseases were used for the training and validation of the diagnostic program. A total of 1610 images of 426 patients from different hospitals were used as test datasets. The performance of the diagnostic program was compared with nephropathologists. Results: In >90% of the tested images, the glomerulus location module achieved an intersection over union >0.8. The accuracy of the D-CNN in recognizing irregular granular mesangial deposition and fine granular deposition along the glomerular basement membrane was 96.1% and 93.3%, respectively. As for the diagnostic program, the accuracy, sensitivity and specificity of diagnosing suspected IgAN were 97.6%, 94.4% and 96.0%, respectively. The accuracy, sensitivity and specificity of diagnosing suspected IMN were 91.7%, 88.9% and 95.8%, respectively. The corresponding areas under the curve (AUCs) were 0.983 and 0.935. When tested with images from the outside hospital, the diagnostic program showed stable performance. The AUCs for diagnosing suspected IgAN and IMN were 0.972 and 0.948, respectively. Compared with inexperienced nephropathologists, the program showed better performance. Conclusion: The proposed diagnostic program could assist the IF diagnosis of IgAN and IMN.

Urgency for Kidney Palliative Care in Chinese Maintenance Hemodialysis Patients.

Introduction: The aim of this study is to understand nephrology medical staff's awareness of, basic knowledge of, practical ability of, and the barriers to palliative kidney care to patients on maintenance hemodialysis (HD) in mainland China. Methods: This cross-sectional descriptive study employed convenience sampling of medical staff (physicians and nurses) working in nephrology departments in mainland China. Independent predictors of self-assessment ability for palliative care (PC) were determined using multivariate binary logistic regression. Results: Responses were received from medical staff in 28 provinces and 657 questionnaires were analyzed. Among the participants, 53.1% (349/657) were doctors, and only 4.3% claimed to be confident in providing PC to patients on HD. The average score of self-assessing ability for PC was 2.65 ± 1.15 (range 1-5). Among the 580 participants who experienced patient withdrawal from dialysis, only 16.0% reported that their patients had well-planned withdrawal from dialysis. Male (odds ratio [OR] [95% confidence interval [CI], 0.585 [0.34-0.99], P = 0.048), nurse (OR [95% CI], 1.81 [1.01-3.27], P = 0.047), more experience in dealing with deceased cases (OR [95% CI], 1.28 [1.02-1.61], P = 0.034), less experience of medical disputes before/after withdrawal from dialysis (OR [95% CI], 0.62 [0.40-0.98], P = 0.041), and PC training experiences (OR [95% CI], 2.33 [1.86-2.91], P < 0.001) were independently correlated with significant better self-assessing ability for PC. Conclusion: This study demonstrates that the nephrology medical staff had a positive attitude but lacked relative knowledge and training in PC. Institutionalized education, training models, practice guidelines for kidney PC, and guidelines for well-planned withdrawal from dialysis according to cultural background are urgently needed in mainland China.

Development of a multimodal kidney age prediction based on automatic segmentation CT image in patients with normal renal function.

Background: For decades, description of renal function has been of interest to clinicians and researchers. Serum creatinine (Scr) and estimated glomerular filtration rate (eGFR) are familiar but also limited in many circumstances. Meanwhile, the physiological volumes of the kidney cortex and medulla are presumed to change with age and have been proven to change with decreasing kidney function. Methods: We recruited 182 patients with normal Scr levels between October 2021 and February 2022 in Peking Union Medical College Hospital (PUMCH) with demographic and clinical data. A 3D U-Net architecture is used for both cortex and medullary separation, and volume calculation. In addition, we included patients with the same inclusion criteria but with diabetes (PUMCH-DM test set) and diabetic nephropathy (PUMCH-DN test set) for internal comparison to verify the possible clinical value of "kidney age" (K-AGE). Results: The PUMCH training set included 146 participants with a mean age of 47.5 ± 7.4 years and mean Scr 63.5 ± 12.3 µmol/L. The PUMCH test set included 36 participants with a mean age of 47.1 ± 7.9 years and mean Scr 66.9 ± 13.0 µmol/L. The multimodal method predicted K-AGE approximately close to the patient's actual physiological age, with 92% prediction within the 95% confidential interval. The mean absolute error increases with disease progression (PUMCH 5.00, PUMCH-DM 6.99, PUMCH-DN 9.32). Conclusion: We established a machine learning model for predicting the K-AGE, which offered the possibility of evaluating the whole kidney health in normal kidney aging and in disease conditions.

Renal Outcomes in Older Adults with Antineutrophil Cytoplasmic Autoantibody-Associated Vasculitis: A New Prediction Model.

INTRODUCTION: Older patients with antineutrophil cytoplasmic autoantibody-associated vasculitis (AAV) commonly experience renal impairment and poor prognoses. This study aimed to establish a risk-scoring system for predicting composite renal outcomes in older patients with AAV. METHODS: This retrospective observational study included all patients with AAV hospitalized in a single-center tertiary hospital in China between January 2013 and April 2022. Patients aged ≥65 years were defined as older adults and short-term composite renal outcomes included a ≥25% reduction in estimated glomerular filtration rate (eGFR) (for AKI), renal replacement therapy, provision of renal replacement therapy (long-term dialysis, kidney transplant, or sustained eGFR <15 mL/min/1.73 m), or all-cause mortality. Patients were randomly divided into development and validation cohorts (2:1). Logistic regression analysis was performed in the development cohort to analyze risk factors. The scoring system was established accordingly and further validated in the validation cohort. RESULTS: 1,203 patients were enrolled in the study, among whom the older adult group accounted for 36% with a mean age of 71. The older adult group had a worse prognosis, a higher mortality rate, a higher rate of end-stage renal disease, and worsening renal function. Logistic regression showed that age >75 years, chronic heart disease, and elevated serum creatinine and D-dimer values were risk factors for poor prognosis in patients with AAV. The development and validation cohorts in patients with AAV produced area under the curve values of 0.82 (0.78-0.86) and 0.83 (0.77-0.89), respectively. CONCLUSION: We established a risk-scoring system based on baseline clinical characteristics to predict composite renal outcomes in patients with AAV. Our results suggest that more attention should be paid to older patients with severe renal impairment and active inflammation.

Multidimensional Landscape of SA-AKI Revealed by Integrated Proteomics and Metabolomics Analysis.

Sepsis-associated acute kidney injury (SA-AKI) is a severe and life-threatening condition with high morbidity and mortality among emergency patients, and it poses a significant risk of chronic renal failure. Clinical treatments for SA-AKI remain reactive and non-specific, lacking effective diagnostic biomarkers or treatment targets. In this study, we established an SA-AKI mouse model using lipopolysaccharide (LPS) and performed proteomics and metabolomics analyses. A variety of bioinformatic analyses, including gene set enrichment analysis (GSEA), weighted gene co-expression network analysis (WGCNA), protein and protein interactions (PPI), and MetaboAnalyst analysis, were conducted to investigate the key molecules of SA-AKI. Integrated proteomics and metabolomics analysis revealed that sepsis led to impaired renal mitochondrial function and metabolic disorders. Immune-related pathways were found to be activated in kidneys upon septic infection. The catabolic products of polyamines accumulated in septic kidneys. Overall, our integrated analysis provides a multidimensional understanding of SA-AKI and identifies potential pathways for this condition.

Clinical characteristics and primary outcomes of patients with ANCA-associated vasculitis and central diabetes insipidus.

Introduction: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is characterized by systemic small-vessel vasculitis and may rarely present as central diabetes insipidus (CDI). In this study, we aimed to determine the clinical characteristics and prognosis of patients with AAV-associated CDI. Methods: This was a nested case-control study where AAV patients with CDI at the Peking Union Medical College Hospital were followed from January 2012 to April 2022. Case-control matching with AAV patients without CDI was performed (1:5), and participants were matched by age, sex, and AAV classification. We collected clinical data every 3-6 months and conducted a literature review using PubMed to identify relevant articles published from 1983-2022. Results: Among 1203 hospitalized AAV patients, 16 patients with CDI were included (1.3%). The average age was 49 years, and men accounted for 56.3%. Granulomatosis with polyangiitis (GPA) accounted for 87.5% of patients. AAV patients with CDI had more ear, nose, and throat (ENT) (81.3%) involvement and less renal impairment than those in the control group (P<0.05). After a mean follow-up of four years, 50% of patients were in remission from AAV, 37.5% relapsed, and 12.5% died. Our literature review suggested that patients in Asian countries tend to be older men and have higher myeloperoxidase (MPO-ANCA) positivity than those in Western countries. Furthermore, proteinase 3 (PR3-ANCA) positivity may predict disease recurrence. Discussion: AAV patients with CDI had more ENT involvement and a higher eGFR. MPO-ANCA positivity is more commonly observed in Asian countries than Western countries, and PR3-ANCA positivity may predict recurrence.

Clinicopathological Features of Gitelman Syndrome with Proteinuria and Renal Dysfunction.

INTRODUCTION: Gitelman syndrome (GS) is a rare renal tubular salt-wasting disorder. Besides kidney electrolyte loss, proteinuria and renal dysfunction were also observed. However, their incidence, risk factors, pathological features, and prognosis were unclear. METHODS: We retrospectively reviewed 116 GS patients and analyzed their clinical, genetic, and pathological characteristics. We also systematically reviewed articles on GS with proteinuria and renal dysfunction. RESULTS: Twenty-three GS patients had proteinuria (69.6%) and renal dysfunction (43.5%) with a mean age of 35.3 ± 13.2 years, and 65.2% were male. Compared to patients without proteinuria or renal dysfunction, these patients had elevated plasma angiotensin II level (440.2 ± 351.7 vs. 253.2 ± 187.4 pg/mL, p = 0.031) and three times higher incidence of diabetes. The renal pathology of nine biopsied patients indicated hypertrophy of the juxtaglomerular apparatus (100%), chronic tubulointerstitial changes (66.7%), intrarenal vascular changes (66.7%), and glomerulopathy (55.6%). More extensive renin staining was observed in patients with GS than in the control group with glomerular minor lesion (p < 0.001). During a median of 85 months (range, 11-205 months) of follow-up for 19 out of the 23 GS-renal patients, the renal function was generally stable, except one died of cancer and one developed end-stage renal disease because of concomitant membranous nephropathy and IgA nephropathy. CONCLUSION: Proteinuria and renal dysfunction were more common than expected and might indicate glomerulopathy and vascular lesions besides a tubulointerstitial injury in GS. Renal function may maintain stable with effective therapy in most cases.

Aldehyde dehydrogenase 2 alleviates mitochondrial dysfunction by promoting PGC-1α-mediated biogenesis in acute kidney injury.

Renal tubular epithelial cells are one of the high energy-consuming cell types, which mainly depend on mitochondrial energy supply. Aldehyde dehydrogenase 2 (ALDH2) is a key enzyme that is involved in alcohol metabolism and mitochondrial oxidative ATP production; however, its function in mitochondrial homoeostasis in acute kidney injury (AKI) is unclear. Here, we found that ALDH2 expression was predominantly decreased in cisplatin or maleic acid (MA) models both in vivo and in vitro. ALDH2 knockout (KO) mice exhibited exacerbated kidney impairment and apoptosis of tubular epithelial cells after cisplatin injection. In contrast, ALDH2 activation alleviated AKI and tubular cell apoptosis in both cisplatin- and MA-induced models. RNA sequencing revealed that the oxidative phosphorylation pathway was positively enriched in the renal tissues after Alda-1 pre-treatment in MA-induced mice. ALDH2 activation restored mitochondrial structure, mitochondrial membrane potential, and respiration rate, but downregulated glycolysis in MA-induced mice and human renal proximal tubular epithelial (HK-2) cells. Mechanistically, co-immunoprecipitation assays revealed that ALDH2 interacts with peroxisomal proliferator-γ coactivator-1α (PGC-1α), a master regulator of mitochondrial biogenesis, and advanced its nuclear translocation. Subsequently, PGC-1α knockdown almost abolished the improvement of ALDH2 activation on MA-induced tubular epithelial cells damage. Thus, our study revealed that ALDH2 activation alleviated mitochondrial dysfunction in AKI by enhancing PGC-1α-mediated mitochondrial biogenesis. Hence, ALDH2 may act as a potential therapeutic target to prevent AKI progression.