Inflammatory biomarkers in staging of chronic kidney disease: elevated TNFR2 levels accompanies renal function decline

Association of Chronic Kidney Disease With Dietary Inflammatory Index in Adults Aged 50 Years and Older: Dose-Response Analysis of a Nationally Representative Population-Based Study

OBJECTIVE

Dietary inflammatory index (DII) is associated with systemic inflammatory markers, which have been linked to the development of chronic kidney disease (CKD). However, epidemiological studies on the association of DII scores with CKD are sparse. This study aimed to quantitatively assess the dose-response relationship of DII scores with the prevalence of CKD.

METHODS

Adults (≥50 years) from the 2007 to 2018 National Health and Nutrition Examination Survey (N = 12,090) were included. DII scores were calculated based on 27 nutritional parameters. The outcome of interest is the prevalence of CKD 3-5 stages, which is defined as an estimated glomerular filtration rate <60 mL/min/1.73 m2. The nonlinear dose-response relationship of DII scores with the prevalence of CKD stages 3-5 was assessed with restricted cubic splines. Stratified analyses were conducted by age, sex, and race/ethnicity. Covariates included age, sex, body mass index, race/ethnicity, education, ratio of family income to poverty, smoking, physical activity, hypertension, diabetes, and daily intakes of total plain water, sodium, and energy.

RESULTS

The weighted prevalence of CKD stages 3-5 was 14.77%. The relationship of DII scores with CKD stages 3-5 was linear, and the odds ratios (95% confidence intervals) of CKD stages 3-5 were 0.68 (0.51-0.84) for -2 (DII score), 0.83 (0.74-0.93) for -1, 1.00 for 0 (reference value), 1.20 (1.07-1.32) for 1, 1.41 (1.16-1.66) for 2, 1.63 (1.28-1.98) for 3, 1.84 (1.34-2.34) for 4, and 2.08 (1.30-2.86) for 5. The linear relationship pattern of DII scores with CKD stages 3-5 was observed in stratified analyses by age, sex, and race/ethnicity, respectively.

CONCLUSIONS

Higher DII scores were independently and linearly associated with the odds of CKD stages 3-5, which deserves to be confirmed in further prospective cohort studies.

Klotho exerts protection in chronic kidney disease associated with regulating inflammatory response and lipid metabolism

BACKGROUND

The anti-aging protein Klotho plays a protective role in kidney disease, but its potential as a biomarker for chronic kidney disease (CKD) is controversial. Additionally, the main pathways through which Klotho exerts its effects on CKD remain unclear. Therefore, we used bioinformatics and clinical data analysis to determine its role in CKD.

RESULTS

We analyzed the transcriptomic and clinical data from the Nephroseq v5 database and found that the Klotho gene was mainly expressed in the tubulointerstitium, and its expression was significantly positively correlated with estimated glomerular filtration rate (eGFR) and negatively correlated with blood urea nitrogen (BUN) in CKD. We further found that Klotho gene expression was mainly negatively associated with inflammatory response and positively associated with lipid metabolism in CKD tubulointerstitium by analyzing two large sample-size CKD tubulointerstitial transcriptome datasets. By analyzing 10-year clinical data from the National Health and Nutrition Examination Survey (NHANES) 2007-2016, we also found that Klotho negatively correlated with inflammatory biomarkers and triglyceride and positively correlated with eGFR in the CKD population. Mediation analysis showed that Klotho could improve renal function in the general population by modulating the inflammatory response and lipid metabolism, while in the CKD population, it primarily manifested by mediating the inflammatory response. Restricted cubic spline (RCS) analysis showed that the optimal concentration range for Klotho to exert its biological function was around 1000 pg/ml. Kaplan-Meier curves showed that lower cumulative hazards of all-cause mortality in participants with higher levels of Klotho. We also demonstrated that Klotho could reduce cellular inflammatory response and improve cellular lipid metabolism by establishing an in vitro model similar to CKD.

CONCLUSIONS

Our results suggest that Klotho exerts protection in CKD, which may be mainly related to the regulation of inflammatory response and lipid metabolism, and it can serve as a potential biomarker for CKD.

Soluble Tumor Necrosis Factor Receptor 2: A Promising Predictive Biomarker for Renal Dysfunction in Membranous Glomerulonephritis

Background and objective Membranous glomerulonephritis (MGN) is a common cause of adult nephrotic syndrome. Tumor necrosis factor-α (TNF-α) is a proinflammatory cytokine that signals by attaching to TNF receptors. TNF-α plays a pivotal role in the development and progression of different forms of glomerulonephritis. Several research findings suggest that TNF-α receptors (TNFR1 and TNFR2) are predictors of estimated glomerular filtration rate (eGFR) decline. In light of this, this study aimed to explore the relationship between TNFR2 and eGFR, as well as the predictive role of TNFR2 in eGFR decline in MGN. Methods A total of 50 consecutive patients with a diagnosis of primary MGN based on renal biopsies and clinical workups were included in the study. TNFR2 levels in serum, urine, and gene expression were evaluated at baseline and after three months of follow-up by using enzyme-linked immunosorbent assay (ELISA) kits for TNFR2 (KTE60215, Abbkine, Wuhan, China). Cox regression was employed to determine the predictive significance of TNFR2 in persistent eGFR decline. Additionally, an ROC curve analysis was conducted to assess the prognostic value of TNFR2 in predicting persistent eGFR decline among MGN patients. Results We assessed the levels of inflammatory markers TNF-α and TNFR2, examined their correlation with eGFR and renal injury, and investigated their potential in predicting persistent eGFR. Patients with MGN exhibited elevated levels of TNFR2 in their serum, urine, and gene expression compared to healthy individuals. Additionally, there was a positive correlation between serum TNFR2 and TNF-α, urine protein-creatinine ratio (UPCR), uric acid, and total cholesterol. Conversely, there was a negative correlation with eGFR, serum albumin, and calcium. Serum TNFR2 showed statistical significance in a univariate Cox regression analysis (HR: 1.010, 95% CI: 1.00-1.01, p = 0.045) for predicting a persistent decline in eGFR. However, it did not show significance concerning relapse and remission. An ROC curve was created to assess TNFR2's prognostic potential as a biomarker, demonstrating an AUC of 0.683, with a sensitivity of 68% and specificity of 64%. Conclusions Based on our findings, TNFR2 is a predictive biomarker for eGFR decline in MGN, correlating with renal inflammation and predicting deterioration in renal function. TNFR2 emerges as a promising biomarker for early identification in patients at risk of renal function decline.

Systemic immune-inflammation Index is associated with chronic kidney disease in the U.S. population: insights from NHANES 2007-2018

Objectives

The systemic immune-inflammation index (SII), a novel and systematic inflammatory biomarker that is associated with chronic kidney disease (CKD), has not received much attention. This study aimed to investigate the relationship between SII and CKD in the United States (U.S.) population.

Methods

Our study ultimately included a nationally representative sample of 10,787 adults who participated in the 2007-2018 National Health and Nutrition Examination Survey. Weighted multivariate logistic regression was used to assess the correlation between SII and CKD, and a restricted cubic spline (RCS) model was subsequently used to explore the non-linear relationship between SII and CKD. Subgroup analyses were performed to further the effects of other covariates on the relationship between SII and CKD.

Results

Following confounder adjustment, a higher SII was related to the incidence of CKD (OR =1.36; 95% CI, 1.07-1.73; p =0.01), as validated by multivariable logistic regression. The RCS curve revealed a non-linear positive correlation between SII/1000 and CKD incidence (p for non-linear =0.0206). Additionally, subgroup analysis confirmed a stronger correlation for male participants (OR =2.628; 95% CI, 1.829-3.776) than for female participants (OR =1.733; 95% CI, 1.379-2.178) (p for interaction =0.046).

Conclusions

SII is positively associated with the incidence of CKD among U.S. adults, especially in males. However, further studies are needed to confirm our findings and explore the causal factors that can contribute to the prevention and treatment of CKD.

Plasma MCP-1 and TGF-β1 Levels are Associated with Kidney Injury in Children with Congenital Anomalies of the Kidney and Urinary Tract

Congenital anomalies of the kidney and urinary tract (CAKUT) are primarily causal for end-stage renal disease and have significant implications for long-term survival. A total of 39 healthy controls and 94 children with chronic kidney disease (CKD) were enrolled (3-12 years old as children, 13-18 years old as adolescents), who were divided into CAKUT and Non-CAKUT according to the etiology of CKD. CKD group was further classified according to estimating glomerular filtration rate (eGFR). Circulating levels of inflammatory markers such as interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), monocyte chemokine-1 (MCP-1), and transforming growth factor-β1 (TGF-β1) were analyzed. The relationship between these inflammatory markers with eGFR and the kidney injury parameter (urine protein) was investigated to assess their potential as early markers of disease progression. All circulating levels of these inflammatory cytokines were increased in CKD patients (including CAKUT and Non-CAKUT) compared with healthy subjects. The circulating levels of MCP-1 and TGF-β1 were increased in CAKUT adolescents compared with CAKUT children. In CAKUT children, levels of MCP-1 and TGF-β1 increased as CKD progressed, and MCP-1 and TGF-β1 were negatively and significantly correlated with eGFR and positively with urine protein. MCP-1 and TGF-β1 may contribute to the early detection of CKD and disease stage/progression in CAKUT children.

Predictors of Kidney Function Outcomes and Their Relation to SGLT2 Inhibitor Dapagliflozin in Patients with Type 2 Diabetes Mellitus Who Had Chronic Heart Failure

INTRODUCTION

Sodium-glucose cotransporter 2 inhibitors (SGLT2i) have a favorable impact on the kidney function in patients with heart failure (HF), while there is no clear evidence of what factors predict this effect. The aim of the study was to identify plausible predictors for kidney function outcome among patients with HF and investigate their association with SGLT2i.

METHODS

We prospectively enrolled 480 patients with type 2 diabetes mellitus (T2DM) treated with diet and metformin and concomitant chronic HF and followed them for 52 weeks. In the study, we determined kidney outcome as a composite of ≥ 40% reduced estimated glomerular filtration rate from baseline, newly diagnosed end-stage kidney disease or kidney replacement therapy. The relevant medical information and measurement of the biomarkers (N-terminal natriuretic pro-peptide, irisin, apelin, adropin, C-reactive protein, tumor necrosis factor-alpha) were collected at baseline and at the end of the study.

RESULTS

The composite kidney outcome was detected in 88 (18.3%) patients of the entire population. All patients received guideline-recommended optimal therapy, which was adjusted to phenotype/severity of HF, cardiovascular risk and comorbidity profiles, and fasting glycemia. Levels of irisin, adropin and apelin significantly increased in patients without clinical endpoint, whereas in those with composite endpoint the biomarker levels exhibited a decrease with borderline statistical significance (p = 0.05). We noticed that irisin ≤ 4.50 ng/ml at baseline and a ≤ 15% increase in irisin serum levels added more valuable predictive information than the reference variable. However, the combination of irisin ≤ 4.50 ng/ml at baseline and ≤ 15% increase in irisin serum levels (area under curve = 0.91; 95% confidence interval = 0.87-0.95) improved the discriminative value of each biomarker alone.

CONCLUSION

We suggest that low levels of irisin and its inadequate increase during administration of SGLT2i are promising predictors for unfavorable kidney outcome among patients with T2DM and concomitant HF.

Molecular mechanisms of metabolic disease-associated hepatic inflammation in non-alcoholic fatty liver disease and non-alcoholic steatohepatitis

Non-alcoholic fatty liver disease (NAFLD) is the leading chronic liver disease worldwide, with a progressive form of non-alcoholic steatohepatitis (NASH). It may progress to advanced liver diseases, including liver fibrosis, cirrhosis, and hepatocellular carcinoma. NAFLD/NASH is a comorbidity of many metabolic disorders such as obesity, insulin resistance, type 2 diabetes, cardiovascular disease, and chronic kidney disease. These metabolic diseases are often accompanied by systemic or extrahepatic inflammation, which plays an important role in the pathogenesis and treatment of NAFLD or NASH. Metabolites, such as short-chain fatty acids, impact the function, inflammation, and death of hepatocytes, the primary parenchymal cells in the liver tissue. Cholangiocytes, the epithelial cells that line the bile ducts, can differentiate into proliferative hepatocytes in chronic liver injury. In addition, hepatic non-parenchymal cells, including liver sinusoidal endothelial cells, hepatic stellate cells, and innate and adaptive immune cells, are involved in liver inflammation. Proteins such as fibroblast growth factors, acetyl-coenzyme A carboxylases, and nuclear factor erythroid 2-related factor 2 are involved in liver metabolism and inflammation, which are potential targets for NASH treatment. This review focuses on the effects of metabolic disease-induced extrahepatic inflammation, liver inflammation, and the cellular and molecular mechanisms of liver metabolism on the development and progression of NAFLD and NASH, as well as the associated treatments.

Chronic Kidney Disease: Underlying Molecular Mechanisms-A Special Issue Overview

Chronic kidney disease (CKD) is an epidemic health issue that requires global attention [...].

TNFR2 as a Potential Biomarker for Early Detection and Progression of CKD

The inflammatory pathway driven by TNF-α, through its receptors TNFR1 and TNFR2, is a common feature in the pathogenesis of chronic kidney disease (CKD), regardless of the initial disease cause. Evidence correlates the chronic inflammatory status with decreased renal function. Our aim was to evaluate the potential of TNF receptors as biomarkers for CKD diagnosis and staging, as well as their association with the progression of renal lesions, in rat models of early and moderate CKD. We analyzed the circulating levels of inflammatory molecules—tumor necrosis factor-alpha (TNF-α), tumor necrosis factor receptor 1 (TNFR1) and 2 (TNFR2) and tissue inhibitor of metalloproteinase-1 (TIMP-1)—and studied their associations with TNFR1 and TNFR2 renal expression, glomerular and tubulointerstitial lesions, and with biomarkers of renal (dys)function. An increase in all inflammatory markers was observed in moderate CKD, as compared to controls, but only circulating levels of both TNFR1 and TNFR2 were significantly increased in the early disease; TNFR2 serum levels were negatively correlated with eGFR. However, only TNFR2 renal expression increased with CKD severity and showed correlations with the score of mild and advanced tubular lesions. Our findings suggest that renal TNFR2 plays a role in CKD development, and has potential to be used as a biomarker for the early detection and progression of the disease. Still, the potential value of this biomarker in disease progression warrants further investigation.