Evolving Concepts on Inflammatory Biomarkers and Malnutrition in Chronic Kidney Disease

Associations of Intact and C-Terminal FGF23 with Inflammatory Markers in Older Patients Affected by Advanced Chronic Kidney Disease

Background: In patients with chronic kidney disease (CKD), Fibroblast Growth Factor 23 (FGF23) is markedly increased and has been proposed to interact with systemic inflammation. Methods: In this cross-sectional study, we evaluated the correlations of intact FGF23, c-terminal FGF23, and the FGF23 ratio (c-terminal to intact) with some inflammatory cytokines in 111 elderly patients with advanced CKD not yet in dialysis. Results: Estimated glomerular filtration rate (eGFR) was inversely correlated with intact FGF23 and c-terminal FGF23, as well as with interleukin 6 (IL-6), tumor necrosis factor alpha (TNFα), and monocyte chemoattractant protein-1 (MCP-1). Intact FGF23 levels were directly correlated with IL-6 (r = 0.403; p < 0.001) and TNFα (r = 0.401; p < 0.001) while c-terminal FGF23 was directly correlated with MCP-1 (r = 0.264; p = 0.005). The FGF23 ratio was, instead, inversely correlated with IL-6 (r = -0.326; p < 0.001). Multivariate analysis revealed that intact FGF23 was directly associated with TNFα [B = 0.012 (95% CI 0.006, 0.019); p = 0.003] and c-terminal FGF23 was directly associated with MCP-1 [B = 0.001 (95% CI 0.000, 0.002); p = 0.038], while the FGF23 ratio was inversely correlated with IL-6 [B = -0.028 (95% CI -0.047, -0.010); p = 0.002]. Conclusions: Our data demonstrate that, in CKD patients, intact FGF23 and the metabolites deriving from its proteolytic cleavage are differently associated with some inflammatory pathways. In particular, intact FGF23 is mainly associated with IL-6 and TNFα, c-terminal FGF23 with MCP-1, and the FGF23 ratio with IL6.

Replacement of the massive amino acid losses induced by hemodialysis: A new treatment option proposal for a largely underestimated issue

BACKGROUND

A series of interesting literature reports acknowledges the notable loss of essential and non-essential amino acids (EAAs and NEAAs) during hemodialysis sessions. These losses may exceed 800 g/year, thus contributing towards accelerating the onset of malnutrition in hemodialysis patients (HD).

OBJECTIVE

A novel tailored amino acid formula for oral administration was developed to replace total amounts of each individual amino acid lost during dialysis diffusive/convective HD strategies, monitoring the effects produced on nutritional and hematological status.

METHODS

A three-month randomized double-blind study was conducted on 30 subjects over the age of 70 years extrapolated from a total population of 86 hemodialysis patients. The 30 patients were randomly assigned to two groups: a treatment group of 15 HD patients (TG) to whom a novel mixture containing 5.4 g of AAs was administered solely on interdialytic days, and a control group of 15 HD patients (CG) who received no amino acid supplementation. The AAs mixture was administered post-dialysis at an extended interval from the end of solute and compartmental rebound to replace AA losses and optimize their role in protein anabolism.

RESULTS

The results obtained highlighted a significant improvement in protein intake g/kg/day (Protein Catabolic Rate, p = 0.014), and increased IgG (p = 0.008) and C3 serum levels (p = 0.003) in the TG group alone. Fat mass losses were initially confirmed by means of bioelectrical impedance analysis (BIA) (p = 0.011) and plicometry (p < 0.001) in the CG group alone, although the main objective was to preserve nutritional status and, particularly, muscle mass. The study was extended to investigate the effects produced on anemia, yielding evidence of continued positive effects three months after the end of the study in the TG group alone based on an increase in Hb levels from 11.2 ± 0.6 to 12.1 ± 0.6 (p = 0.004) associated with a reduced demand for erythropoietin i.v. from 12928 ± 9033 to 9286 ± 5398 U.I/week (p = 0.012) and iron i.v. from 75.9 ± 55 to 71.4 ± 33.4 mg/week (p = 0.045).

CONCLUSIONS

The results obtained following oral administration of this novel tailored AA replacement mixture aimed at reinstating the high AA losses produced during hemodialysis suggest the mixture should be prescribed as a standard procedure to all HD patients.

A systematic review of epigenetic interplay in kidney diseases: Crosstalk between long noncoding RNAs and methylation, acetylation of chromatin and histone

The intricate crosstalk between long noncoding RNAs (lncRNAs) and epigenetic modifications such as chromatin/histone methylation and acetylation offer new perspectives on the pathogenesis and treatment of kidney diseases. lncRNAs, a class of transcripts longer than 200 nucleotides with no protein-coding potential, are now recognized as key regulatory molecules influencing gene expression through diverse mechanisms. They modulate the epigenetic modifications by recruiting or blocking enzymes responsible for adding or removing methyl or acetyl groups, such as DNA, N6-methyladenosine (m6A) and histone methylation and acetylation, subsequently altering chromatin structure and accessibility. In kidney diseases such as acute kidney injury (AKI), chronic kidney disease (CKD), diabetic nephropathy (DN), glomerulonephritis (GN), and renal cell carcinoma (RCC), aberrant patterns of DNA/RNA/histone methylation and acetylation have been associated with disease onset and progression, revealing a complex interplay with lncRNA dynamics. Recent studies have highlighted how lncRNAs can impact renal pathology by affecting the expression and function of key genes involved in cell cycle control, fibrosis, and inflammatory responses. This review will separately address the roles of lncRNAs and epigenetic modifications in renal diseases, with a particular emphasis on elucidating the bidirectional regulatory effects and underlying mechanisms of lncRNAs in conjunction with DNA/RNA/histone methylation and acetylation, in addition to the potential exacerbating or renoprotective effects in renal pathologies. Understanding the reciprocal relationships between lncRNAs and epigenetic modifications will not only shed light on the molecular underpinnings of renal pathologies but also present new avenues for therapeutic interventions and biomarker development, advancing precision medicine in nephrology.

The advanced lung cancer inflammation index is associated with mortality in peritoneal dialysis patients

BACKGROUND

There is still a very high morbidity and mortality rate for patients undergoing peritoneal dialysis (PD). The advanced lung cancer inflammation index (ALI) has been demonstrated to be associated with the prognosis in multiple types of cancers. Like in cancer, systemic chronic low-grade inflammation is one of the distinguishing features of PD patients. Therefore, we aimed to investigate the relationships between the ALI and all-cause and cardiovascular disease (CVD) mortality in PD patients.

METHODS

Patients who started PD at Shaoxing People's Hospital between 1 January 2013 and 31 December 2020 (n = 277) were recruited and followed up until 1 July 2023. They were divided into high-ALI group and low-ALI group according to the median of ALI. Kaplan-Meier curves and multivariate Cox regression analyses were used to assess the associations between the ALI and all-cause and CVD mortality. Receiver operating characteristic (ROC) curves were constructed, and the area under the curve (AUC) was calculated to determine the predictive power of the ALI for all- cause and CVD mortality.

RESULTS

During the median follow-up of 40.50 months (interquartile range, 26.42-59.77 months), a total of 55 patients died, 31 of whom died due to CVD. Kaplan-Meier curves revealed that patients in the low-ALI group had significantly lower cumulative and cardiovascular cumulative survival rates than did those in the high-ALI group (all P < 0.001). After we corrected for confounders, the risk of all-cause and CVD mortality was significantly greater in the low-ALI group than in the high-ALI group [hazard ratio (HR) 1.944, 95% confidence interval (CI) 1.068-3.540, P = 0.030, and HR 2.672, 95% CI 1.188-6.009, P = 0.017, respectively]. The predictive value of ALI (AUC = 0.708, 95% CI 0.630-0.786, P < 0.001) for all-cause mortality was superior to albumin (AUC = 0.644, 95% CI 0.556-0.726, P < 0.001), body mass index (AUC = 0.581, 95% CI 0.496-0.659, P = 0.069) and neutrophil-to-lymphocyte ratio (AUC = 0.675, 95% CI 0.596-0.754, P < 0.001).

CONCLUSION

A lower ALI is an independent risk factor for all-cause and cardiovascular mortality in PD patients. The ALI may be an effective indicator for predicting outcomes in PD patients.

Early Detection of Inflammation and Malnutrition and Prediction of Acute Events in Hemodialysis Patients through PINI (Prognostic Inflammatory and Nutritional Index)

Protein-energy wasting and inflammation are major risk factors for complications in hemodialysis patients. As these risk factors are triggered by a pro-inflammatory state, oxidative stress and hemodynamic dysfunction, which overlap in hemodialyzed subjects, we aimed to assess the efficacy of a cost-effective and straightforward screening tool, the Prognostic Inflammatory and Nutritional Index (PINI), in regularly screening maintenance hemodialysis (MHD) patients, to detect early signs of inflammation and malnutrition. A 12-month follow-up was carried out on a cohort of 102 adult patients undergoing maintenance dialysis, during which the Prognostic Inflammatory and Nutritional Index (PINI) was calculated using the formula alpha1-Acid Glycoprotein (AGP) × C-reactive protein (CRP)/albumin (ALB) × transthyretin (TTR). A PINI score < 1 was considered normal. The patients were stratified based on their PINI score: 66 patients (64.70%) had a normal score, below 1, while 36 patients (35.30%) had a PINI score ≥ 1. Despite the absence of clinical evidence of inflammation at enrollment, the latter group exhibited higher levels of CRP. During the follow-up period, all patients with a PINI score ≥ 1 experienced at least one acute event, compared to only 6% of patients with a normal PINI score, which presented COVID-19 infection as an acute event. The evaluation of the PINI can effectively identify the silent malnutrition-inflammation syndrome and predict the risk of acute events. This straightforward test appears to be a rapid tool that is independent of the examiner's experience and subjectivity, thereby potentially reducing hospitalization costs.

Innovative Treatments to Counteract Endothelial Dysfunction in Chronic Kidney Disease Patients

In chronic kidney disease (CKD) patients, several risk factors contribute to the development of endothelial dysfunction (ED), which can be described as an alteration in the cell structure or in the function of the endothelium. Among the well-known CKD-related risk factors capable of altering the production of endothelium-derived relaxing factors, we include asymmetric dimethylarginine increase, reduced dimethylarginine dimethylamine hydrolase enzyme activity, low-grade chronic systemic inflammation, hyperhomocysteinemia, oxidative stress, insulin resistance, alteration of calcium phosphorus metabolism, and early aging. In this review, we also examined the most important techniques useful for studying ED in humans, which are divided into indirect and direct methods. The direct study of coronary endothelial function is considered the gold standard technique to evaluate if ED is present. In addition to the discussion of the main pharmacological treatments useful to counteract ED in CKD patients (namely sodium-glucose cotransporter 2 inhibitors and mineralocorticoid receptor antagonist), we elucidate innovative non-pharmacological treatments that are successful in accompanying the pharmacological ones. Among them, the most important are the consumption of extra virgin olive oil with high intake of minor polar compounds, adherence to a plant-dominant, low-protein diet (LPD), an adaptive physical activity program and, finally, ketoanalogue administration in combination with the LPD or the very low-protein diet.

Role and Mechanism of Growth Differentiation Factor 15 in Chronic Kidney Disease

GDF-15 is an essential member of the transforming growth factor-beta superfamily. Its functions mainly involve in tissue injury, inflammation, fibrosis, regulation of appetite and weight, development of tumor, and cardiovascular disease. GDF-15 is involved in various signaling pathways, such as MAPK pathway, PI3K/AKT pathway, STAT3 pathway, RET pathway, and SMAD pathway. In addition, several factors such as p53, ROS, and TNF-α participate the regulation of GDF-15. However, the specific mechanism of these factors regulating GDF-15 is still unclear and more research is needed to explore them. GDF-15 mainly improves the function of kidneys in CKD and plays an important role in the prediction of CKD progression and cardiovascular complications. In addition, the role of GDF-15 in the kidney may be related to the SMAD and MAPK pathways. However, the specific mechanism of these pathways remains unclear. Accordingly, more research on the specific mechanism of GDF-15 affecting kidney disease is needed in the future. In conclusion, GDF-15 may be a therapeutic target for kidney disease.

The efficacy and safety of sertraline in maintenance hemodialysis patients with depression: A randomized controlled study

OBJECTIVE

To determine the efficacy and safety of sertraline in maintenance hemodialysis (MHD) patients with depression.

METHODS

A randomized controlled trial was conducted involving 125 MHD patients with depression. The treatment group received sertraline, while the control group did not receive any antidepressant treatment. After 12 weeks, we compared the changes in the Hamilton Depression Rating Scale (HAMD), the Medication Adherence Report Scale-5 (MARS-5), the Mini Nutritional Assessment short-form (MNA-SF), the Kidney Disease Quality of Life-36 (KDQOL-36) scores, selected clinical and laboratory indicators, and the incidence of drug-related adverse reactions between the two groups.

RESULTS

After 12 weeks of treatment, the HAMD scores of patients in the treatment group significantly decreased compared to before treatment and were lower than those in the control group. The KDQOL-36, MARS-5, and MNA-SF scores in the treatment group also significantly improved compared to before treatment and were superior to those in the control group. Albumin and hemoglobin levels in the treatment group significantly increased, while C-reactive protein significantly decreased. The incidence of nausea was slightly higher in the treatment group, and was mostly relieved after reducing the dosage of sertraline.

LIMITATIONS

This study is a single-center, small-sample study with a relatively short duration of treatment and follow-up.

CONCLUSIONS

Sertraline can alleviate depressive symptoms, and improve the quality of life and treatment compliance of MHD patients, while improving chronic inflammation, malnutrition, and anemia. However, starting with a low dose and reducing the maintenance dose is recommended when administering sertraline.

Exploring systemic inflammation in children with chronic kidney disease: correlates of interleukin 6

BACKGROUND

Systemic inflammation (SI) is linked to chronic kidney disease (CKD) progression and multiple complications. Data regarding SI biomarkers in pediatric patients are scarce. This case-control and cross-sectional study investigates the correlation of neutrophil-lymphocyte ratio (NLR), platelet-lymphocyte ratio (PLR), total iron binding capacity (TIBC) and serum albumin to serum interleukin-6 (IL-6).

METHODS

NLR and PLR were measured in 53 patients (median age: 12.9 years), including 17 on dialysis and 36 with a median glomerular filtration rate of 39 ml/min/1.73m2, and in 25 age and sex-matched healthy controls. Iron profile, serum albumin and IL-6 were measured in the patient group. IL-6 levels > 3rd quartile were classified as high.

RESULTS

Patients presented higher NLR and PLR and particularly those on dialysis (p < 0.001 and p = 0.001). We observed a significant correlation between natural logarithm (ln) of IL-6 (lnIL-6) and NLR (rs = 0.344, p = 0.014), serum albumin (rs = -0.350, p = 0.011) and TIBC (rs = -0.345, p = 0.012) after adjustment for CKD stage, while the correlation between lnIL-6 and PLR was not significant (rs = 0.206, p = 0.151). Combination of NLR, serum albumin and TIBC predicted high IL-6 (13 patients) with an AUC of 0.771 (95% CI 0.608-0.943). Pairing of NLR ≥ 1.7 and TIBC ≤ 300 μg/dL exhibited the highest sensitivity (76.9%), while incorporating serum albumin ≤ 3.8 g/dL along with them achieved the highest specificity (95%) for detecting high IL-6 levels.

CONCLUSION

Both NLR and PLR levels increase in CKD, especially in patients on chronic dialysis. NLR, rather than PLR, along with TIBC and serum albumin, are associated with IL-6 in pediatric CKD.

Cerebral blood flow changes in maintenance hemodialysis patients with restless legs syndrome and their clinical significance:a cross-sectional case-control study

OBJECTIVE

Restless legs syndrome (RLS) stands as a prevalent neurological complication within maintenance hemodialysis (MHD) patients. However, the alterations in cerebral blood flow (CBF) among MHD-RLS patients remain uncharted. Through the utilization of the arterial spin labeling (ASL) technique, we evaluated the fluctuations in CBF within distinct brain regions and analyzed the risk factors for the development of RLS in MHD patients in the context of the clinic.

METHODS

Thirty-one MHD patients with concomitant RLS (MHD-RLS group) and thirty-one non-RLS patients matched based on age, gender, as well as cognitive function (MHD-nRLS group) were included. Through image preprocessing and data analysis, the changes in CBF values in distinct brain regions were obtained, and the CBF values of brain regions with substantial differences between the two groups were correlated with the RLS scores. Furthermore, the differences in baseline data were compared, and through the utilization of multifactorial logistic regression, the independent risk factors for the development of RLS were examined.

RESULTS

Compared with the MHD-nRLS group, the MHD-RLS group had increased CBF in the right superior temporal gyrus, reduced CBF in the right hippocampus, left middle frontal gyrus, inferior frontal gyrus of right triangle, middle frontal gyrus of left orbit, left precentral gyrus, and left precuneus. Only left precentral gyrus CBF were negatively correlated with RLS scores after correction for dialysis duration(r = -0.436, P = 0.016). Accordingly, multifactorial regression analysis by stepwise method yielded that the left precentral gyrus CBF values(OR: 0.968, 95%CI: 0.944-0.993, P = 0.012) remained an independent risk factor for RLS in MHD patients. In addition, the results showed that hemodialysis duration (OR: 1.055, 95%CI: 1.014-1.098, P = 0.008) and serum iron levels (OR: 0.685, 95%CI: 0.551-0.852, P = 0.001) were also risk factors for the development of RLS.

CONCLUSION

Patients afflicted with MHD-RLS exhibit alterations in CBF across several brain regions. Notably, the left precentral gyrus might serve as a pivotal region influencing the onset of RLS among MHD patients. Furthermore, extended hemodialysis duration and a relative insufficiency in serum iron levels independently contribute as risk factors for RLS development within the MHD patient population.

Novel biomarkers related to oxidative stress and immunity in chronic kidney disease

Introduction

The incidence of chronic kidney disease (CKD) has been increasing in recent years, gradually becoming a global health crisis. Due to limited treatment options, novel molecular pathways are urgently required to advance the treatment and diagnosis of CKD.

Materials and methods

The characteristics of differentially expressed genes (DEGs) in CKD patients were analyzed using Gene Expression Omnibus (GEO) database, and genes related to oxidative stress were retrieved from the Genecard database. Subsequently, a comprehensive approach was applied, including immune infiltration analysis, weighted gene co-expression network analysis (WGCNA) and protein-protein interaction (PPI) network analysis, to identify hub genes among differentially expressed immune-related oxidative stress genes (DEIOSGs). Validation of hub genes was performed using an external data set, and diagnostic potential capability was evaluated through receiver operating curve (ROC) analysis. In animal experiments, the expression of hub genes in CKD was confirmed by inducing a CKD model through a 5/6 nephrectomy procedure. Finally, the relationship between these hub genes and clinical characteristics were assessed using the Nephroseq v5 database.

Results

29 DEIOSGs were identified by comprehensive bioinformatics analysis. PPI analysis screened the hub genes NCF2, S100A9, and SELL. ROC analysis demonstrated excellent diagnostic efficacy. Further validation from other databases and animal experiments confirmed a substantial upregulation in the expression of hub genes in CKD. Additionally, clinical correlation analysis established a clear link between hub gene expression and renal function deterioration.

Conclusions

Our study confirms NCF2, S100A9, and SELL as diagnostic biomarkers associated with immune response and oxidative stress in CKD, suggesting their potential as novel targets for CKD diagnosis and treatment.

Beyond Borders of the Cell: How Extracellular Vesicles Shape COVID-19 for People with Cystic Fibrosis

The interaction between extracellular vesicles (EVs) and SARS-CoV-2, the virus causing COVID-19, especially in people with cystic fibrosis (PwCF) is insufficiently studied. EVs are small membrane-bound particles involved in cell-cell communications in different physiological and pathological conditions, including inflammation and infection. The CF airway cells release EVs that differ from those released by healthy cells and may play an intriguing role in regulating the inflammatory response to SARS-CoV-2. On the one hand, EVs may activate neutrophils and exacerbate inflammation. On the other hand, EVs may block IL-6, a pro-inflammatory cytokine associated with severe COVID-19, and protect PwCF from adverse outcomes. EVs are regulated by TGF-β signaling, essential in different disease states, including COVID-19. Here, we review the knowledge, identify the gaps in understanding, and suggest future research directions to elucidate the role of EVs in PwCF during COVID-19.

Association of Dietary Inflammatory Index with CKD progression and estimated glomerular filtration rate in the American CKD population: A cross-sectional study

PURPOSE

The number of CKD patients is on the rise worldwide, and diet has become an essential aspect influencing the treatment and prognosis of CKD. However, limited research has explored the association of the Dietary Inflammatory Index (DII) with CKD progression and the essential kidney function indicator, eGFR, in CKD patients. This study aimed to analyze the association between DII and CKD progression and eGFR in the US CKD population using data from the National Health and Nutrition Examination Survey (NHANES).

METHODS

This study utilized data obtained from the National Health and Nutrition Examination Survey (NHANES) spanning from 2007 to 2018, with a total sample size of 2,488 individuals. Study used multiple imputation, based on 5 replications and a chained equation approach method in the R MI procedure, to account for missing data. Weighted multiple logistic regression was used to analyze the relationship between DII and the risk of higher CKD stage and a weighted multiple regression analysis was used to assess the relationship between DII and eGFR. Weighted Generalized Additive Models and smoothed curve fitting were applied to detect potential non-linear relationships in this association.

RESULTS

In all three models, it was found that DII was positively associated with the risk of higher CKD stage (P < 0.0001), and an increase in DII was associated with a decrease in eGFR (P < 0.0001). The trend across quartiles of DII remained statistically significant, revealing a gradual elevation in higher CKD stage risk and reduction in eGFR levels for the second, third, and fourth quartiles compared to the lowest quartile (P for trend < 0.0001). Upon adjusting for age, gender, race, education level, poverty income ratio (PIR), marital status, body mass index (BMI), metabolic equivalent (MET) score, drinking, smoking, history of hypertension, history of diabetes, cotinine, systolic blood pressure, diastolic blood pressure, total triglycerides, and total cholesterol, we found a positive correlation between DII and the risk of higher CKD stage (OR = 1.26, 95% CI: 1.14-1.40). Further investigation revealed that an increase in DII was associated with a decrease in eGFR (β = -1.29, 95% CI: -1.75, -0.83). Smooth curves illustrated a non-linear positive correlation between DII and CKD risk, while a non-linear negative correlation was observed between DII and eGFR.

CONCLUSIONS

Our study results indicate that an increase in DII is associated with an increased risk of higher CKD stage and a decrease in eGFR in all three models. In the fully adjusted model, the risk of higher CKD stage increased by 26% and the eGFR decreased by 1.29 ml/min/1.73 m2 for each unit increase in DII. This finding suggests that in patients with CKD in the US, improved diet and lower DII values may help slow the decline in eGFR and delay the progression of CKD.

Hyperparathyroidism, Serum Phosphorus and Dietary Intake in Hemodialysis Patients: Is There a Novel Relationship?

The management of hyperparathyroidism (intact parathyroid hormone (iPTH) serum levels > 585 pg/mL), frequently focuses on the appropriate control of mineral and bone markers, with the decrease in serum and dietary phosphorus as two of the targets. We aimed to investigate the association between iPTH, serum phosphorus levels and dietary intake. This was a cross-sectional, multicenter, observational study with 561 patients on hemodialysis treatment. Clinical parameters, body composition and dietary intake were assessed. For the analysis, patients were divided into three groups: (a) iPTH < 130, (b) iPTH between 130 and 585 and (c) iPTH > 585 pg/mL. The association between PTH, serum phosphorus and dietary intake was analyzed using linear regression models. In the whole sample, 23.2% of patients presented an iPTH > 585 pg/mL. Patients with higher iPTH levels were those with longer HD vintage and lower ages, higher serum phosphorus, serum calcium, Ca/P product, albumin and caffeine intake, and a lower dietary intake of phosphorus, fiber, riboflavin and folate. Higher serum phosphorus predicted higher iPTH levels, even in the adjusted model. However, lower dietary phosphorus and fiber intake were predictors of higher iPTH levels, including in the adjusted model. Our results bring new data to the relationship between dietary intake and iPTH values. Despite higher serum phosphorus being observed in patients with HPTH, an opposite association was noted regarding dietary phosphate and fiber.

Relationship between immune nutrition index and all-cause and cause-specific mortality in U.S. adults with chronic kidney disease

Objective

The available evidence regarding the association of immune nutrition status with chronic kidney disease (CKD) is limited. Thus, the present study examined whether immunonutrition indices were associated with renal function and mortality among CKD individuals.

Research design and methods

This study enrolled 6,099 U.S. adults with CKD from the NHANES 2005-2018 database. Participants were matched with National Death Index records until 31 December 2019 to determine mortality outcomes. The time-dependent receiver operating characteristic was utilized to identify the most effective index among the prognostic nutritional index (PNI), system inflammation score (SIS), Naples prognostic score (NPS), and controlling nutritional status (CONUT) for predicting mortality. Cox regression models were employed to evaluate the associations of immunonutrition indices with mortality in participants with CKD.

Results

The PNI exhibited the strongest predictive power among the four indices evaluated and the restricted cubic spline analysis revealed a cutoff value of 51 for the PNI in predicting mortality. During a median follow-up of 72 months (39-115 months), a total of 1,762 (weighted 24.26%) CKD participants died from all causes. The Kaplan-Meier curve demonstrated a reduced risk of death for the subjects with a higher PNI compared to those in the lower group. Besides, after adjusting for multiple potential confounders, a higher PNI remained an independent predictor for lower risks of all-cause mortality (HR 0.80, 95%CI: 0.71-0.91, p < 0.001) and cardiovascular disease (CVD) mortality (HR 0.69, 95%CI: 0.55-0.88, p = 0.002) in individuals with CKD.

Conclusion

In CKD, a higher PNI level was significantly associated with lower mortality from all causes and CVD. Thus, the clinical utility of this immunonutrition indicator may facilitate risk stratification and prevent premature death among patients with CKD.

Animal protein intake is directly associated with serum level of pentraxin 3 in hemodialysis patients

Inflammation plays an important role in Cardiovascular disease (CVD) pathogenesis as the main cause of mortality in hemodialysis (HD) patients. Despite the relevance of nutrition and dietary intakes for inflammation status, the role of dietary protein sources remains unclear. The aim of this study was to evaluate the association between the different types of dietary protein and pentraxin 3 (PTX3) levels in HD patients. In this multi-center cross-sectional study, 227 adult patients undergoing HD for a minimum 90 days were recruited. A validated 168-item food frequency questionnaire was used to assess dietary intakes. Also, 5 ml blood samples were collected from each patient to measure the concentration of serum PTX3. Overall, 227 patients, including 63 women and 164 men, with a mean age of 58 years, participated in this study. There was a greater intake of animal protein per kilogram dry weight among patients with higher levels of PTX3 (0.46 vs. 0.54 g/kg; P = 0.035). In contrast, consumption of total protein and plant protein per kilogram dry weight was not different across PTX3 levels. Moreover, the chance of increased PTX3 concentration was directly associated with a one-unit increase in animal protein intake per kilogram dry weight, after adjusting for confounders. We did not observe any association between one-unit increases in plant protein intake per kilogram dry weight and chance of increased PTX3. In conclusion, animal protein intake was directly associated with circulating PTX3.

Screening of key genes in the pathogenesis of muscle atrophy in CKD-PEW children based on RNA sequencing

BACKGROUND

In children with CKD, Protein Energy Wasting (PEW) is common, which affects the outcome of children and is an important cause of poor prognosis. We are aiming to explore the pathogenesis of muscle wasting in CKD-PEW children.

METHODS

Blood samples of 32 children diagnosed with chronic kidney disease (CKD) and protein energy wasting (PEW) in our hospital from January 2016 to June 2021 were collected. RNA sequencing and bioinformatics analysis were performed.

RESULTS

Based on GO (Gene Ontology) functional enrichment analysis, KEGG (Kyoto Encyclopedia of Genes and Genomes) pathway enrichment analysis and differential gene expression analysis, a total of 25 CKD-PEW related genes were obtained including CRP, IL6, TNF, IL1B, CXCL8, IL12B, IL12A, IL18, IL1A, IL4, IL10, TGFB2, TGFB1, TGFB3, ADIPOQ, NAMPT, RETN, RETNLB, LEP, CD163, ICAM1, VCAM1, SELE, NF-κB1, NF-κB2. The most significantly differentially expressed gene was NF-κB2 (adjusted P = 2.81 × 10-16), and its expression was up-regulated by 3.92 times (corresponding log2FoldChange value was 1.979). Followed by RETN (adjusted P = 1.63 × 10-7), and its expression was up-regulated by 8.306 times (corresponding log2FoldChange value was 2.882). SELE gene were secondly significant (adjusted P = 5.81 × 10-7), and its expression was down-regulated by 22.05 times (corresponding log2FoldChange value was -4.696).

CONCLUSIONS

A variety of inflammatory factors are involved in the pathogenesis of CKD-PEW in children, and chronic inflammation may lead to the development of muscle atrophy in CKD-PEW. It is suggested for the first time that NF-κB is a key gene in the pathogenesis of muscle wasting in CKD-PEW children, and its increased expression may play an important role in the pathogenesis of muscle wasting in children with CKD-PEW.

An Overview of Chronic Kidney Disease Pathophysiology: The Impact of Gut Dysbiosis and Oral Disease

Chronic kidney disease (CKD) is a severe condition and a significant public health issue worldwide, carrying the burden of an increased risk of cardiovascular events and mortality. The traditional factors that promote the onset and progression of CKD are cardiometabolic risk factors like hypertension and diabetes, but non-traditional contributors are escalating. Moreover, gut dysbiosis, inflammation, and an impaired immune response are emerging as crucial mechanisms in the disease pathology. The gut microbiome and kidney disease exert a reciprocal influence commonly referred to as "the gut-kidney axis" through the induction of metabolic, immunological, and endocrine alterations. Periodontal diseases are strictly involved in the gut-kidney axis for their impact on the gut microbiota composition and for the metabolic and immunological alterations occurring in and reciprocally affecting both conditions. This review aims to provide an overview of the dynamic biological interconnections between oral health status, gut, and renal pathophysiology, spotlighting the dynamic oral-gut-kidney axis and raising whether periodontal diseases and gut microbiota can be disease modifiers in CKD. By doing so, we try to offer new insights into therapeutic strategies that may enhance the clinical trajectory of CKD patients, ultimately advancing our quest for improved patient outcomes and well-being.

Elevated Lipoprotein(a) Levels are Associated with Arterial Stiffness Measured by Cardio-Ankle Vascular Index in Patients Undergoing Peritoneal Dialysis

Background

Arterial stiffness (AS) can be used to predict future cardiovascular diseases. High lipoprotein(a) (Lp(a)) levels were independently correlated with cardiovascular (CV) morbidity and death in patients with chronic renal insufficiency. The cardio-ankle vascular index (CAVI) is a useful biomarker of arteriosclerotic disorders and has a close relationship with a variety of CV events. This study aimed to investigate the correlation between serum Lp(a) levels and AS in patients on peritoneal dialysis (PD) using the CAVI.

Methods

A total of 86 adult patients who were on regular PD for at least 3 months were recruited in this study. The CAVI values were determined using the waveform device (VaSera VS-1000). A CAVI value of ≥ 9.0 on either side was defined as high. Serum Lp(a) levels were measured by an enzyme-linked immunosorbent assay.

Results

Among these participants, 35 of 86 (40.7%) belonged to the high CAVI group. In contrast to those with a normal CAVI, PD recipients in the high CAVI group had higher serum levels of total cholesterol (p = 0.003), triglycerides (p = 0.044), C-reactive protein (p < 0.001), and Lp(a) (p < 0.001), whereas their albumin levels were significantly lower (p = 0.026). Based on multivariable logistic regression analysis, serum Lp(a) (odds ratio [OR] 1.025, 95% confidence interval [CI] 1.010-1.040, p = 0.001), total cholesterol (OR 1.042, 95% CI 1.005-1.081, p = 0.027), and C-reactive protein (each increase 0.1 mg/dL, OR 1.217, 95% CI 1.008-1.469, p = 0.041) levels were found as the parameters that could independently predict AS in patients on PD. Further, using Spearman's correlation analysis, both the left and right CAVIs revealed a significantly positive correlation with log-transformed Lp(a) levels (r = 0.588, p < 0.001; r = 0.639, p < 0.001, respectively).

Conclusions

Serum Lp(a) levels were postulated to participate in the pathogenic processes of AS in adult patients undergoing PD.

Assessment of amino-terminal C-type natriuretic peptide serum level and its correlation with high-density lipoprotein structure and function in patients with end stage renal disease before and after kidney transplantation

We aimed to investigate serum amino-terminal C-type natriuretic peptide (NT-proCNP) and its relationship with quantitative and qualitative HDL-parameters in patients with end-stage renal disease (ESRD) before, then 1 and 6 months after kidney transplantation (TX). Seventy patients (47 males, 23 females, mean age 51.7 ± 12.4 years) were enrolled in a prospective follow-up study. We examined serum creatinine, C-reactive protein, procalcitonin, fasting glucose and lipid parameters before, then 1 and 6 months after TX. High-density lipoprotein- (HDL)-associated paraoxonase-1 (PON1) paraoxonase and arylesterase activities were measured spectrophotometrically. Lipoprotein subfractions were determined by Lipoprint. NT-proCNP and oxidized low-density lipoprotein (oxLDL) levels were measured by ELISA. Mean NT-proCNP was 45.8 ± 21.9 pmol/L before renal transplantation and decreased markedly 1 month and 6 months after transplantation (5.3 ± 2.5 and 7.7 ± 4.9 pmol/L, respectively, P = 1 × 10-4). During the 6 months' follow-up, PON1 arylesterase, paraoxonase and salt-stimulated paraoxonase activities improved. NT-proCNP positively correlated with procalcitonin and creatinine and negatively with GFR, LDL-cholesterol (LDL-C) and HDL-cholesterol (HDL-C). There was a negative correlation between serum NT-proCNP and PON1 arylesterase activity. According to the multiple regression analysis, the best predicting variables of NT-proCNP were serum procalcitonin, creatinine and PON1 arylesterase activity. NT-proCNP might be a novel link between HDL dysfunction and impaired vascular function in ESRD, but not after kidney transplantation. Further studies in larger populations are needed to clarify the exact role of NT-proCNP in the risk prediction for cardiovascular comorbidities and complications in ESRD.

Recent Progresses in Optical Biosensors for Interleukin 6 Detection

Interleukin 6 (IL-6) is pleiotropic cytokine with pathological pro-inflammatory effects in various acute, chronic and infectious diseases. It is involved in a variety of biological processes including immune regulation, hematopoiesis, tissue repair, inflammation, oncogenesis, metabolic control, and sleep. Due to its important role as a biomarker of many types of diseases, its detection in small amounts and with high selectivity is of particular importance in medical and biological fields. Laboratory methods including enzyme-linked immunoassays (ELISAs) and chemiluminescent immunoassays (CLIAs) are the most common conventional methods for IL-6 detection. However, these techniques suffer from the complexity of the method, the expensiveness, and the time-consuming process of obtaining the results. In recent years, too many attempts have been conducted to provide simple, rapid, economical, and user-friendly analytical approaches to monitor IL-6. In this regard, biosensors are considered desirable tools for IL-6 detection because of their special features such as high sensitivity, rapid detection time, ease of use, and ease of miniaturization. In this review, current progresses in different types of optical biosensors as the most favorable types of biosensors for the detection of IL-6 are discussed, evaluated, and compared.

Causal effects of systemic inflammatory regulators on chronic kidney diseases and renal function: a bidirectional Mendelian randomization study

Background

While targeted systemic inflammatory modulators show promise in preventing chronic kidney disease (CKD) progression, the causal link between specific inflammatory factors and CKD remains uncertain.

Methods

Using a genome-wide association study of 41 serum cytokines from 8,293 Finnish individuals, we conducted a bidirectional two-sample Mendelian randomization (MR) analysis. In addition, we genetically predicted causal associations between inflammatory factors and 5 phenotypes, including CKD, estimated glomerular filtration rate (eGFR), dialysis, rapid progression of CKD, and rapid decline in eGFR. Inverse variance weighting (IVW) served as the primary MR method, while MR-Egger, weighted median, and MR-pleiotropy residual sum and outlier (MR-PRESSO) were utilized for sensitivity analysis. Cochrane's Q test for heterogeneity. Leave-one-out method ensured stability of MR results, and Bonferroni correction assessed causal relationship strength.

Results

Seventeen cytokines were associated with diverse renal outcomes. Among them, after Bonferroni correction test, higher tumor necrosis factor alpha levels were associated with a rapid decrease in eGFR (OR = 1.064, 95% CI 1.028 - 1.103, P = 0.001), higher interleukin-4 levels were associated with an increase in eGFR (β = 0.003, 95% CI 0.001 - 0.005, P = 0.002), and higher growth regulated oncogene alpha (GROα) levels were associated with an increased risk of CKD (OR=1.035, 95% CI 1.012 - 1.058, P = 0.003). In contrast, genetic susceptibility to CKD was associated with an increase in GROa, and a decrease in eGFR may lead to an increase in stem cell factor. We did not find the presence of horizontal pleiotropy during the analysis.

Conclusion

We discovered causally related inflammatory factors that contribute to the initiation and progression of CKD at the genetic prediction level.

Inflammatory Determinants and Associated Morbidity in Hemodialysis Patients

Hemodialysis deteriorates patients' physical, metabolic, and mental status. Clinical outcomes derived from inflammation determine a worse status but are less frequently identified. The objective of the study was to identify inflammatory determinants and the effect of SNP-related serum IL-6 and IL-10 levels on associated morbidity in hemodialysis. A sample of hemodialysis patients at IMSS Regional Hospital No.46 in Guadalajara (n = 85) were tested using the Malnutrition Inflammation Score (MIS) and Patient Health Questionnaire-9 (PHQ-9) to assess the associated morbidity. Serum cytokine levels were quantified by enzyme-linked immunosorbent assay (ELISA). The restriction fragment length polymorphism (RFLP) technique was used for analysis of IL-6-572C/G and IL-10-1082A/G. Using data visualization methods, we identified relevant determinants of inflammation. A simple regression model was constructed between predictors and targets with genotypes as covariates. Results showed malnutrition in 85.9% of patients and depressive symptoms in 50.6%. IL-10 was the most relevant inflammatory determinant, with regression coefficients (R2) between 0.05 and 0.11. The GG genotype of IL-10-1082 A/G evinced small effect on both clinical outcomes (δ of 0.35 and 0.37, respectively). Hemodialysis increases the associated morbidity, cytokines act as inflammatory determinants, and genetic variability contributes to the severity of clinical outcomes. Further studies need to refine the causal relationship between inflammation and CKD.

The Contribution of Muscle Innate Immunity to Uremic Cachexia

Protein energy wasting (PEW) is a common complication both in chronic kidney disease (CKD) and end-stage kidney disease (ESKD). Of note, PEW is one of the stronger predictors of morbidity and mortality in this patient population. The pathogenesis of PEW involves several mechanisms, including anorexia, insulin resistance, acidosis and low-grade inflammation. In addition, "sterile" muscle inflammation contributes to PEW at an advanced CKD stage. Both immune and resident muscle cells can activate innate immunity; thus, they have critical roles in triggering "sterile" tissue inflammation. Toll-like receptor 4 (TLR4) can detect endogenous danger-associated molecular patterns generated or retained in blood in uremia and induce a sterile muscle inflammatory response via NF-κB in myocytes. In addition, TLR4, though the activation of the NLRP3 inflammasome, links the sensing of metabolic uremic stress in muscle to the activation of pro-inflammatory cascades, which lead to the production of IL-1β and IL-18. Finally, uremia-induced accelerated cell senescence is associated with a secretory phenotype that favors fibrosis in muscle. Targeting these innate immune pathways could lead to novel therapies for CKD-related PEW.

Clinical features and predictors of non-cardiac death in patients hospitalised for acute myocardial infarction: Insights from the Tokyo CCU network multicentre registry

BACKGROUND

Patients with acute myocardial infarction (AMI) commonly have multiple comorbidities, and some die in hospitals due to causes other than cardiac complications. However, limited information is available on noncardiac death in patients hospitalised for AMI. Therefore, the present study was performed to determine the incidence, annual trend, clinical characteristics, and predictors of in-hospital non-cardiac death in patients with AMI using the Tokyo Cardiovascular Care Unit (CCU) network registry.

METHODS

The registry included 38,589 consecutive patients with AMI who were admitted to the CCU between 2010 and 2019. The primary endpoint was in-hospital noncardiac death. Further, predictors of cardiac and non-cardiac death were identified.

RESULTS

The incidence of all-cause in-hospital mortality was 7.0% (n = 2700), and the proportion of mortality was 15.6% (n = 420) and 84.4% (n = 2280) for noncardiac and cardiac causes, respectively. The proportion of noncardiac deaths did not change annually over the last decade (p = 0.66). After adjusting for all variables, age, Killip classification grade, peak creatine kinase, hemoglobin, serum creatinine, and C-reactive protein were common predictors of cardiac and non-cardiac deaths. Indicators of malnutrition, such as lower body mass index (kg/m²) [odds 0.94, 95%CI (0.90-0.97), p < 0.001] and serum low-density lipoprotein cholesterol level (per 10 mg/dl) [odds 0.92, 95%CI (0.89-0.96), p < 0.001] were the specific predictors for non-cardiac deaths.

CONCLUSIONS

The incidence of in-hospital noncardiac death was significant in patients with AMI, accounting for 15.6% of all in-hospital mortalities. Thus, prevention and management of non-cardiac complications are vital to improve acute-phase outcomes, especially those with predictors of non-cardiac death.

The Effect of Prognostic Nutritional Index on Infection in Acute Ischemic Stroke Patients

Objectives: Malnutrition is frequently seen in stroke patients. Malnutrition worsens the prognosis and increases the mortality rate in acute ischemic stroke patients. Malnutrition is a significant factor not only in the initiation of infection but also in its progression. The prognostic nutritional index (PNI) is a new index that evaluates the nutrition and inflammatory status. This study aims to investigate the relationship between PNI and stroke-related infection (SRI) development during hospitalization in patients with acute ischemic stroke. Materials and Methods: Acute ischemic stroke was the primary diagnosis for 158 patients who were admitted to the neurology intensive care unit. Patients' demographic, clinical, and laboratory parameters were recorded. PNI was calculated according to the formula given below. PNI: 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (mm³). PNI > 380 normal, PNI: 350-380 moderate malnutrition risk, PNI < 350 severe malnutrition risk. Results: A total of 158 patients with acute ischemic stroke were included in the study. There were 70 male and 88 female patients, whereas the mean age of the patients was 67.79 ± 14.0 years. Nosocomial infection developed in 34 (21%) of the patients. Compared to high PNI scores, patients with low PNI scores were generally older, and the National Institutes of Health Stroke Scale (NIHSS) score, atrial fibrillation, infection, mortality rate, and hospitalization rates were all significantly higher. Conclusions: In this study, we discovered that patients with poor PNI had a considerably increased rate of infection development. It is vital to evaluate the nutritional status of patients with acute ischemic stroke during hospitalization.

Chronic Kidney Disease—State of Either “Too Much” or “Too Little”

Chronic kidney disease (CKD) is a world-wide phenomenon with an increasing incidence and prevalence [...]

Lymphocyte-to-C reactive protein ratio as novel inflammatory marker for predicting outcomes in hemodialysis patients: A multicenter observational study

Background

Patients undergoing hemodialysis experience inflammation, which is associated with a higher risk of mortality. The lymphocyte-to-C reactive protein ratio (LCR) is a novel marker of inflammation that has been shown to predict mortality in patients with malignant cancer. However, the utility of LCR has not been evaluated in patients undergoing hemodialysis.

Methods

We performed a multi-center cohort study of 3,856 patients who underwent hemodialysis as part of the Beijing Hemodialysis Quality Control and Improvement Project between 1 January 2012 and December 2019. The relationship between LCR and all-cause mortality was assessed using a restricted cubic spline model and a multivariate Cox regression model. An outcome-oriented method was used to determine the most appropriate cut-off value of LCR. Subgroup analysis was also performed to evaluate the relationships of LCR with key parameters.

Results

Of the 3,856 enrolled patients, 1,581 (41%) were female, and their median age was 62 (53, 73) years. Over a median follow-up period of 75.1 months, 1,129 deaths occurred. The mortality rate for the patients after 60 months was 38.1% (95% confidence interval (CI) 36%-40.1%), resulting in a rate of 93.41 events per 1,000 patient-years. LCR showed an L-shaped dose-response relationship with all-cause mortality. The optimal cut-off point for LCR as a predictor of mortality in hemodialysis patients was 1513.1. An LCR of ≥1513.1 could independently predict mortality (hazard ratio 0.75, 95% CI 0.66-0.85, P<0.001).

Conclusions

Baseline LCR was found to be an independent prognostic biomarker in patients undergoing hemodialysis. Implying that it should be a useful means of improving patient prognosis and judging the timing of appropriate interventions in routine clinical practice.

Association between Malnutrition and Delirium in Older Chronic Kidney Disease Patients Admitted to Intensive Care Units: A Data Linkage Study

BACKGROUND

Independently, malnutrition and delirium in older hospitalised adults is prevalent. However, there is limited evidence on the association between these two conditions in older hospitalised adults with chronic kidney disease (CKD).

OBJECTIVES

To determine the association between malnutrition and delirium in older CKD patients admitted to intensive care units (ICU).

METHODS

This data linkage study utilised administrative data from New South Wales (NSW) hospitals in Australia between 2017 and 2020.Admitted patient data was linked with Cause of Death Unit Record File, and NSW Registry of Deaths (RBD). The study population comprised all CKD patients aged 65 and over admitted to ICUs. Descriptive statistics were used to summarise patient characteristics. Binary logistic tested for association between malnutrition and delirium.

RESULTS

The study population included 748 CKD patients with a total 948 admissions in the study period. The International Statistical Classification of Diseases and Related Health Problems 10th Revision (ICD-10) was used to code for all outcomes and comorbidities. The incidence of delirium was 15.5% (n=141) and malnutrition was recorded in 11.3% (n=103) across all admissions. The adjusted odds ratio (OR) of a delirium diagnosis was 2.07 (95% CI: 1.27-3.39) for CKD patients that were malnourished compared to non-malnourished CKD patients.

CONCLUSIONS

This study showed a significant association between delirium and malnutrition in older CKD patients admitted to ICU. Management of malnutrition could be critical in reducing the risk of delirium in older hospitalized patients with CKD. Additionally, more education and awareness around delirium and its association with malnutrition are needed in clinical practice.

Effects of the Malnutrition-Eat Additional Meal (MEAM) Diet on the Serum Levels of Albumin and C-Reactive Protein in Hemodialysis Patients

The main objective of this project was to evaluate the efficiency of two kinds of nutritional intervention implemented in hemodialysis patients for 24 weeks (traditional nutritional intervention without a meal served before dialysis for group HG1, and nutritional intervention involving a meal served before dialysis for group HG2), and their impact on nutritional status and serum concentrations of C-reactive protein (CRP). Nutritional status and serum biochemical parameters were analyzed in the control group (CG, n = 70) and in two homogeneous groups of patients, HG1 (n = 35) and HG2 (n = 35). There was an interesting trend in both groups of patients connected with increased intake, mainly of energy and protein. In HG1, the greatest increase in energy intake was observed on Sundays, and in HG2 on the days with dialysis. In HG2, after 24 weeks of the nutritional intervention, an increase in serum albumin (p = 0.0157) and a decrease in CRP concentration (p = 0.0306) were observed, whereas in HG1 there was a decrease in serum albumin concentration (p = 0.0043) with no significant change in CRP concentration. The nutritional intervention applied, called the Malnutrition-Eat Additional Meal (MEAM) diet with an easily digestible meal served before dialysis, was aimed at improving the patients' nutritional status and the obtained results indicate the need not only for substantial reeducation of hemodialysis patients in the area of their diet, but also for undertaking further research and discussions on the possibility of ensuring adequate meals for hemodialysis patients before the dialysis procedure.

Malnutrition and Erythropoietin Resistance among Patients with End-Stage Kidney Disease: Where Is the Perpetrator of Disaster?

BACKGROUND

Hemodialyzed patients with poor erythropoietin response tend to have low volume of visceral adipose tissue and score high on malnutrition-inflammation score. This study investigates in-depth the role of leptin and chosen cytokines in the development of malnutrition-inflammation syndrome (MIS) and erythropoietin resistance.

METHODS

Eighty-one hemodialyzed patients with erythropoietin-treated anemia were enrolled in the study. Their body composition was measured. Erythropoietin resistance index was calculated. Blood samples for leptin, IL-6, IL-18, TNF-alpha, and IL-1-alpha serum levels were drawn.

RESULTS

Leptin showed negative correlation with erythropoietin resistance index (ERI), whilst IL-6 showed the opposite. IL-6 seemed to be linked more to HD parameters and vintage, while TNF-alpha and leptin were more dependent on body composition. IL-18 and IL-1-alpha did not affect nutritional parameters nor ERI.

CONCLUSION

Modulation of adipokine- and cytokine-related signaling is a promising target in tempering malnutrition in hemodialyzed, and thus achieving better outcomes in anemia treatment. Large clinical studies that target the inflammatory response in hemodialysis, especially regarding IL-6, TNF-alpha, and leptin, would be of great worth.