Does inflammation affect outcomes in dialysis patients?

Associations Between Inflammatory and Bone Turnover Markers and Mortality in Hemodialysis Patients

Background/Objectives: Chronic kidney disease-mineral and bone disorder (CKD-MBD) and systemic inflammation contribute to mortality in hemodialysis (HD) patients. The primary aim of this study was to determine whether specific CKD-MBD markers and inflammatory biomarkers are associated with increased mortality risk in HD patients. Methods: We conducted a retrospective cohort study on 63 stage 5D CKD patients undergoing maintenance HD. Serum intact parathyroid hormone (iPTH), soluble Klotho, calcium, phosphorus, 25(OH)D (25-hydroxyvitamin D), transforming growth factor-beta (TGF-β), vascular endothelial growth factor (VEGF), C-reactive protein (CRP), and interleukin-6 (IL-6) were analyzed. A Cox regression analysis assessed mortality predictors, and linear regression analysis evaluated CKD-MBD-inflammation correlations. Results: Lower iPTH (<329.3 pg/mL) levels were the only significant mortality predictor (p = 0.042). Other CKD-MBD markers (calcium, phosphorus, 25(OH)D, VEGF, TGF-β) did not impact survival. Soluble Klotho correlated positively with IL-6 (r = 0.57, p < 0.001), suggesting a compensatory inflammatory response. Conclusions: Our findings demonstrate that low iPTH levels and advanced age are independent predictors of mortality in hemodialysis patients. The positive association between soluble Klotho and IL-6 suggests a potential compensatory inflammatory response. These results highlight the need for further research to clarify underlying mechanisms and to explore novel therapeutic strategies.

Drivers and mechanisms of cognitive decline in chronic kidney disease

Cognitive impairment is highly prevalent among individuals with chronic kidney disease (CKD). Despite its high prevalence, the contributing factors and mechanisms underlying brain-kidney dysfunction in CKD remain poorly understood. However, advances in neuroscience, including novel imaging techniques and cognitive assessment methods, have begun to clarify this complex relationship. Several factors contribute directly to cognitive decline in people with CKD, including accumulation of uraemic toxins, microvascular damage, malnutrition, chronic inflammation and disruptions in key neuroprotective pathways, such as those involving Klotho and the glymphatic system. These factors are also linked to the accelerated ageing observed in people with CKD, a key contributor to cognitive decline. However, most studies on cognition in people with CKD have been cross-sectional and associative, offering limited insight into causation. Research advances, such as studies on the effect of uraemic toxins on the blood-brain barrier and the role of the endothelial glycocalyx in vascular damage, offer promising new directions. Emerging data from longitudinal cohort studies are also enhancing our understanding of these processes, with potential implications for both the treatment of CKD-related cognitive decline and the broader issue of cognitive dysfunction in ageing populations. Here, we examine key mechanisms linking CKD to cognitive decline and consider potential therapeutic interventions.

Lipid and immunophenotypic profiles in hemodialysis patients with citrate vs. acetate dialysates

Background

Chronic kidney disease (CKD) is a significant cardiovascular (CV) risk factor, with dialysis-dependent CKD (DD-CKD) patients facing high mortality rates. Hypercholesterolemia is another crucial CV risk factor, typically managed with lipid-lowering therapy, though its efficacy in DD-CKD remains uncertain. Evidence shows mixed results regarding the benefits of statins in these patients. Citrate-based dialysates are known to reduce inflammatory biomarkers compared to acetate-based ones, potentially impacting lipid profiles and immune responses. This study aimed to determine the effects of citrate vs. acetate dialysate on lipid profiles and immunophenotypes in DD-CKD patients.

Methods

This unicentric, cross-over, prospective study included 21 hemodialysis patients (10 males, 11 females, average age 62.25 years). Each patient underwent 24 dialysis sessions (12 with each dialysate) and acted as their own control. Lipid profiles, immunological parameters, and nutritional and inflammatory markers were measured before the last session with each dialysate.

Results

After twelve dialysis sessions with citrate dialysate (CD), compared to acetate dialysate (AD), there was a statistically significant decline in TG and remnant cholesterol, with a decrease in HDL and an increase in LDL. Regarding immunology, C3 complement levels were higher, while CD3+ CD8+ and CD16+ 56+ lymphocytes were lower. Finally, total lymphocytes were lower with AD than with CD. We found no difference in predialysis nutritional nor inflammatory parameters except for ESR, which was higher when subjects used CD than AD.

Conclusion

There are significant differences in lipid and immunophenotypic profiles with CD in comparison to AD. Interestingly, there could be an advantageous profile given the reduced amount of remnant cholesterol and TG. However, further studies are needed to understand if the observed changes lead to beneficial hard clinical outcomes in DD-CKD patients.

Biological testing unification for hemodialysis membranes evaluation: A step towards standardization

Current hemodialysis treatments can cause adverse effects, many of which are linked to the membranes used in the process. These issues are being addressed through new materials and technologies, making it urgent to establish minimum guidelines for evaluating such membranes. This review proposes standardizing the biological tests and variables to evaluate the performance of new membranes, aiming to replicate hemodialysis conditions closely. The tests were categorized into protein adsorption, protein transmission, platelet adhesion, platelet activation, blood coagulation times, hemolysis, complement activation, and cytotoxicity. For protein adsorption, static tests are recommended as an initial step to rule out membrane adhesion, followed by dynamic tests that must be conducted using a crossflow system (>250 mL/min flow) and a solution mimicking real conditions (BSA, lysozyme, trypsin, pepsin, creatinine, urea, albumin, fibrinogen, and γ-globulin). Protein transmission tests must employ dynamic conditions, using human blood or platelet-rich plasma for a minimum time of 3.5 h. Complement activation should be tested using human blood and ELISA assays to detect C3, C5 TCC, and SC5b-9. Blood coagulation times (APTT, TT, FT, TCT, and TAT) should be measured with platelet-poor and platelet-rich plasma. Hemolysis tests should transition from water bath to continuous mode for at least 3.5 h. Cytotoxicity tests should compare the MTT assay with other methods (Alamar Blue, Lactate Dehydrogenase Assay, Flow Cytometry, or Trypan Blue Exclusion Test) and use different cell types for comprehensive validation. By implementing these minimum biological tests, membrane evaluations would more accurately reflect the real-world applications, ensuring biocompatibility, effectiveness, and efficiency.

Influence of autonomic neuropathy, systemic inflammation and other clinical parameters on mortality in dialysis patients

Background

Autonomic neuropathy (AN) is prevalent in diabetes and chronic kidney disease. The Composite Autonomic Symptom Score 31 (COMPASS 31) is a self-assessment test developed to determine not only cardiac AN but also AN of other organs, including the vasomotor, pupillomotor, secretomotor, and gastrointestinal systems. As yet there are no data on the effects of combined AN-scores of a variety of affected organ systems on mortality in dialysis patients.

Methods

In 119 patients undergoing hemodialysis therapy, symptoms of AN were documented using COMPASS 31. After 5 years, survival rates were calculated depending on AN scores and other parameters. After this 5-year period, AN scores were assessed for a second time and correlated with those obtained 5 years earlier.

Results

Survival rates for patients with lower AN scores were better than for those with higher AN scores. Patients with lower C-reactive protein levels showed better survival compared to those with higher values. Dialysis patients with diabetes had a lower survival rate compared to non-diabetic patients. In women, survival rates were better than in men. AN scores remained unchanged over the 5-year period.

Conclusion

AN is frequently observed in dialysis patients and can be identified through the COMPASS 31 questionnaire. Patients with higher AN scores exhibit poorer survival rates compared to those with lower scores. This observation is applicable not only for cardiac AN but also to AN scores reflecting changes in other organ systems. Therefore, AN scores can be used effectively to detect various AN symptoms in dialysis patients and identify their increased risk of mortality.

Independent Association Between Malnutrition Inflammation Score and C Reactive Protein/Albumin Ratio in Hemodialysis Patients

Introduction

This study aimed to investigate the relationship between the Malnutrition Inflammation Score (MIS) and the C-reactive protein/albumin ratio (CAR) in patients undergoing hemodialysis (HD).

Materials and Methods

Sixty-six End-Stage Renal Disease (ESRD) patients on maintenance hemodialysis were recruited for the study. Malnutrition Inflammation Score, biochemical parameters, and C-reactive protein/albumin ratio were analyzed.

Results

The mean age of the participants was 56.47 ± 17.3 years. A statistically significant positive correlation was found between the CRP/albumin ratio and MIS ≥7 (r = 0.413, p = 0.026), CRP and MIS ≥7 (r = 0.388, p = 0.038) and a negative correlation between albumin and MIS (r = -0.511, p = 0.005). Additionally, MIS was negatively correlated with hemoglobin (r = -0.412, p = 0.026) and creatinine (r = -0.568, p = 0.001), while a positive correlation was found between MIS and ferritin (r = 0.584, p = 0.001) for MIS ≥7. A multiple regression ANOVA model confirmed a significant association between CAR, CRP, albumin, and MIS (F = 6.432, p = 0.002), with significant contributions from CAR (p = 0.003), albumin (p = 0.008), and CRP (p = 0.003).

Conclusion

Our study is the first to show an independent association between CAR and MIS in hemodialysis patients. The CRP/albumin ratio can serve as a valuable indicator of malnutrition in this population, providing a reliable tool for assessing nutritional status.

Medium cut-off dialyzer improves reduction ratios of large middle molecules associated with vascular calcification

BACKGROUND

We aimed to investigate the change in the large middle molecule (>15 kDa) removal rate, which is associated with vascular calcification, when using a medium cut-off (MCO) dialyzer compared to a high-flux (HF) dialyzer.

METHODS

Twenty patients with clinically stable maintenance hemodialysis were investigated over a 15-week study period. Dialyzer efficacies were evaluated during the last midweek hemodialysis treatment for each consecutive dialyzer membrane use: 1st HF, MCO, and 2nd HF dialyzer; 5 weeks each period. Changes in α1-microglobulin (33 kDa) during a dialysis session were analyzed to assess the efficacy of the MCO dialyzer as a reference. The levels and reduction ratios of fibroblast growth factor 23 (FGF23, 32 kDa), osteoprotegerin (OPG, 60 kDa), and sclerostin (22 kDa) were analyzed. Large middle molecules were measured using an enzyme-linked immunosorbent assay.

RESULTS

Serum hemoglobin, phosphorus, and corrected calcium levels were not significantly different for each dialyzer period. Total protein and albumin values during the MCO dialyzer period did not decrease compared with the HF dialyzer period. The reduction ratio of α1-microglobulin was significantly higher in the MCO dialyzer than in the HF dialyzer (p < 0.001). The reduction ratios of FGF23 (p < 0.001), OPG (p < 0.001), and sclerostin (p < 0.001) were significantly higher in the MCO dialyzer than those in the HF dialyzer.

CONCLUSION

The reduction rate of large middle molecules related to vascular calcification, such as FGF23, OPG, and sclerostin, was significantly higher when using the MCO dialyzer than the HF dialyzer.

Prognostic significance of the hs-CRP/Alb ratio for cardiovascular events in patients with end-stage renal disease undergoing maintenance hemodialysis

OBJECTIVE

To evaluate the predictive power of the high-sensitivity C-reactive protein (hs-CRP) to albumin (Alb) ratio for cardiovascular events in patients receiving maintenance hemodialysis (MHD) for end-stage renal disease (ESRD).

METHODS

This retrospective study enrolled 202 ESRD patients undergoing MHD at Bobai County People's Hospital from November 2020 to November 2022, with follow-up extending to November 2023. Patients were divided into two groups based on the occurrence of cardiovascular events during follow-up: the occurrence group (n = 92) and the non-occurrence group (n = 110). Clinical data were compared between these groups. Independent risk factors for cardiovascular events post-MHD were identified using a multivariate logistic regression model. The hs-CRP/Alb ratio's predictive utility was assessed through receiver operating characteristic (ROC) curve analysis, establishing an optimal cutoff value. A decision tree prediction model was developed to further delineate the probability of cardiovascular events.

RESULTS

The occurrence group was older and had a longer duration of dialysis compared to the non-occurrence group (P < 0.05). They also showed a higher prevalence of diabetic and hypertensive nephropathy and a higher proportion of smokers (all P < 0.05). Notably lower levels of hemoglobin (HGB), triglycerides, total cholesterol, low-density lipoprotein, albumin (Alb), and calcium were detected (all P < 0.05), whereas β2-microglobulin (β2-mg), hs-CRP, phosphorus, and the hs-CRP/Alb ratio were markedly increased (all P < 0.05). Multivariate analysis revealed diabetic nephropathy or hypertensive nephropathy, a high hs-CRP/Alb ratio, and elevated phosphorus levels as risk factors for cardiovascular events, while high hemoglobin levels were protective (P < 0.05). The ROC analysis indicated the hs-CRP/Alb ratio (AUC = 0.884) outperformed other predictors with an optimal cutoff at 0.111. Patients with a hs-CRP/Alb ratio ≥ 0.111 were found to have a 29-fold increased risk of cardiovascular events (95% CI: 11.304-74.842).

CONCLUSION

The hs-CRP/Alb ratio is a significant predictive biomarker for cardiovascular events in ESRD patients undergoing MHD. An elevated hs-CRP/Alb ratio is associated with an increased risk of cardiovascular events, underscoring its utility in this patient population.

Acquired Cystic Disease-Associated Renal Cell Carcinoma: A Systematic Review and Meta-analysis

Acquired cystic disease-associated renal cell carcinoma (ACD-RCC) is a common subtype of renal cell carcinoma (RCC) in end-stage renal disease (ESRD) patients. The current systematic review and meta-analysis was performed to evaluate the clinicopathological, and genetic characteristics of patients with ACD-RCC. A systematic search on three electronic databases including the Pubmed, Scopus, and Web of Science databases were performed until December 31, 2022. A meta-analysis was performed following the PRISMA 2020 Guidelines. Of 888 identified articles, full-text screening in 69 articles, there were 26 articles analyzed, with a total of 2314 tumors in 2199 patients, including 418 ACD-RCC tumors in 363 patients, 1340 clear cell RCC (ccRCC) tumors, 308 papillary RCC (pRCC) tumors. Most ACD-RCC patients were male (80.2%). All the ACD-RCC patients underwent prior dialysis with 148.2 months of mean dialysis duration. There were 8.7%, 3.4%, and 5.8% tumors at the T3-4 stage, N1 stage, and M1 stage, respectively. The mean overall survival of ACD-RCC patients was 39.6 months (95% CI, 26.6-52.5). Compared to ccRCC and pRCC, ACD-RCC patients had a longer duration of dialysis (MD: 103.5 and 31.77 months, respectively; 95% CI: [75.48; 131.53] and [0.95; 62.58], respectively), and a higher rate of multifocal tumors (MD: 3.46 and 2.45 tumors, respectively; 95% CI [1.71; 6.98] and [1.26; 4.79], respectively). Regarding genetic characteristics, chromosomes 3 and 16 were the 2 most frequent chromosomal aberrations. The missense mutation in KMT2C (25%) and TSC2 (18.75%) were the 2 most common gene mutations in ACD-RCC. In conclusion, the ACD-RCC subtype exhibited several distinct clinicopathological and genetic characteristics compared to others RCC subtypes. Further researchs are needed to assess the survival outcome and the genetic characteristics of this subtype.

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.

Association between periodontitis and its treatment on mortality rates of end-stage renal disease: A systematic review and meta-analysis

BACKGROUND

The association between periodontitis and systemic diseases is widely researched. Conflicting literature exists on the relationship between periodontitis and the outcomes of end-stage renal disease (ESRD) patients. We hereby reviewed evidence to examine if periodontitis and its management impact the mortality rates of ESRD patients.

MATERIAL AND METHODS

Literature was searched on the databases of PubMed, Embase, CENTRAL, Web of Science, and Scopus till 27th April 2023. All cohort studies reporting adjusted effect size of the relationship between periodontitis or its management and mortality rates of ESRD patients were included.

RESULTS

Eight studies were eligible of which six reported the association between periodontitis and mortality while two reported between periodontal treatment and mortality. Pooled analysis showed no association between the presence of periodontitis and all-cause mortality amongst ESRD patients (HR: 1.13 95% CI: 0.77, 1.65 I2=72%). Results were unchanged on sensitivity analysis. Pooled analysis of three studies showed no difference in the risk of cardiovascular mortality amongst ESRD patients with and without periodontitis (HR: 1.44 95% CI: 0.57, 3.60 I2=86%). A descriptive analysis of two studies showed that periodontal treatment could reduce the risk of mortality in ESRD patients with periodontitis.

CONCLUSIONS

Limited evidence indicates that periodontitis does not impact all-cause and cardiovascular mortality in ESRD patients. Data on the role of periodontal therapy in improving outcomes is scarce. Further research is needed to generate high-quality evidence on this subject.

Patellar and quadriceps tendon rupture are associated with hip fracture in hemodialysis patients with severe hyperparathyroidism

Spontaneous rupture of the patellar (PTR) and quadriceps (QTR) tendon is infrequent. Systemic diseases such as diabetes mellitus, CKD, and secondary hyperparathyroidism (SHPT) are risk factors. The present cohort study aimed to evaluate risk factors associated with tendon rupture in hemodialysis (HD) patients with SHPT, as well as outcomes including surgical complications, re-ruptures, and fracture. Baseline clinical, laboratorial data, and radiographs were analyzed. Patients were followed up from March 2012 to March 2020. One-hundred thirty-one patients (≥18 yr of age, on HD ≥ 6 mo, with SHPT) were included. Incidence rates of PTR and QTR were 2.3 and 1.7/10000 HD patients/yr, respectively. The mean age of patients with tendon rupture was 44.0 ± 11.2 yr. These patients exhibited higher serum levels of phosphorus (6.3 ± 1.5 mg/dL vs 5.6 ± 1.1 mg/dL; P = .005), PTH (2025.7 ± 667.6 pg/mL vs 1728.4 ± 684.8 pg/mL; P = .035), and C-reactive-protein (35.4 ± 32.9 mg/dL vs 17 ± 24.5 mg/dL; P = .002) compared to the group without tendon rupture. The mean follow-up was 56.7 ± 27.1 mo. No patient required a new surgical approach or experienced re-rupture. Of all patients, 31% experienced hip fracture: 50% in the group with rupture (29.5 ± 17.4 mo after the tendon rupture) vs 26% without tendon rupture (P = .015). After adjustment, the hazard ratio for hip fracture was 2.87 (95% CI, 1.27-6.49; P = .012). Patients with SHPT and high levels of phosphorus, PTH, and inflammatory markers were at greater risk for tendon rupture. Surgical complication rates were low. However, results suggest that tendon rupture of knee extensor mechanism in HD patient with SHPT should be regarded as a "red flag" for future hip fracture.

CKD-Associated Pruritus and Clinical Outcomes in Nondialysis CKD

Rationale & Objective

Itching is a frequent symptom experienced by people with chronic kidney disease (CKD). We investigated the associations of CKD-associated pruritus (CKD-aP) with clinical outcomes.

Study Design

This was a longitudinal cohort study.

Setting & Participants

Patients from Brazil, France, and the United States enrolled in the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) from 2013 to 2021, an international prospective cohort study of adults with nondialysis dependent CKD, and an estimated glomerular filtration rate (eGFR) of <60 mL/min/1.73 m2 were included.

Exposure

CKD-aP was self-reported by response to the question: "During the past 4 weeks, to what extent were you bothered by itchy skin?"

Outcomes

The outcomes were as follows: CKD progression, kidney replacement therapy (KRT) initiation, mortality, hospitalization, cardiovascular events, infection events.

Analytical Approach

Associations with time-to-event outcomes were investigated using Cox proportional hazards models adjusted for potential confounders.

Results

There were 4,410 patients from 91 clinics with a median age of 69 years and a median eGFR at patient questionnaire completion of 29 (21-38) mL/min/1.73 m2. The proportion of patients not at all, somewhat, moderately, very much, and extremely bothered by itchy skin was 49%, 27%, 13%, 7%, and 3%, respectively. Patients with more advanced stages of CKD, older age, and greater comorbidities reported to be more likely bothered by itchy skin. Among patients at least moderately bothered, 23% were prescribed at least 1 pharmacotherapy (35% in the United States, 19% in France, 4% in Brazil), including antihistamine (10%), gabapentin (6%), topical corticosteroids (4%), pregabalin (3%), or sedating antihistamine (3%). The HR (95% CI) for patients extremely (vs not at all) bothered was 1.74 (1.11-2.73) for all-cause mortality, 1.56 (1.11-2.18) for all-cause hospitalization, and 1.84 (1.22-2.75) for cardiovascular events. As CKD-aP severity increased, patients also had higher rates of infection events (P = 0.04); CKD-aP severity was not associated with KRT initiation (P = 0.20) or CKD progression (P = 0.87).

Limitations

The limitations were 25% nonresponse rate, recall bias, and residual confounding factors.

Conclusions

These results demonstrate a strong association between severe itch and clinical outcomes, providing the nephrology community new insights into the possible adverse consequences of CKD-aP in individuals with nondialysis CKD, and warrant further exploration.

Plain-Language Summary

Chronic kidney disease-associated pruritus (CKD-aP) is a common disturbing symptom of chronic kidney disease (CKD). This article analyzes longitudinal data from the Chronic Kidney Disease Outcomes and Practice Patterns Study (CKDopps) to describe prevalence of CKD-aP in 4,410 individuals with nondialysis CKD, and its association with clinical outcomes. We found that 51% of the surveyed population were bothered by pruritus. CKD-aP was more prevalent in those with more advanced stages of CKD, older age, and with more comorbid conditions. Compared to those not at all bothered by pruritus, those who were extremely bothered had a higher risk of all-cause mortality, hospitalizations, and cardiovascular events. Severity of CKD-aP was not associated with CKD progression or initiation of kidney replacement therapy.

What is the role of the neutrophil extracellular traps in the cardiovascular disease burden associated with hemodialysis bioincompatibility?

Despite significant progress in dialysis modalities, intermittent renal replacement therapy remains an "unphysiological" treatment that imperfectly corrects uremic disorders and may lead to low-grade chronic inflammation, neutrophil activation, and oxidative stress due to repetitive blood/membrane interactions contributing to the "remaining uremic syndrome" and cardiovascular disease burden of hemodialysis patients. Understanding dialysis bioincompatibility pathways still remains a clinical and biochemical challenge. Indeed, surrogate biomarkers of inflammation including C-reactive protein could not discriminate between all components involved in these complex pathways. A few examples may serve to illustrate the case. Cytokine release during dialysis sessions may be underestimated due to their removal using high-flux dialysis or hemodiafiltration modalities. Complement activation is recognized as a key event of bioincompatibility. However, it appears as an early and transient event with anaphylatoxin level normalization at the end of the dialysis session. Complement activation is generally assumed to trigger leukocyte stimulation leading to proinflammatory mediators' secretion and oxidative burst. In addition to being part of the innate immune response involved in eliminating physically and enzymatically microbes, the formation of Neutrophil Extracellular Traps (NETs), known as NETosis, has been recently identified as a major harmful component in a wide range of pathologies associated with inflammatory processes. NETs result from the neutrophil degranulation induced by reactive oxygen species overproduction via NADPH oxidase and consist of modified chromatin decorated with serine proteases, elastase, bactericidal proteins, and myeloperoxidase (MPO) that produces hypochlorite anion. Currently, NETosis remains poorly investigated as a sensitive and integrated marker of bioincompatibility in dialysis. Only scarce data could be found in the literature. Oxidative burst and NADPH oxidase activation are well-known events in the bioincompatibility phenomenon. NET byproducts such as elastase, MPO, and circulating DNA have been reported to be increased in dialysis patients more specifically during dialysis sessions, and were identified as predictors of poor outcomes. As NETs and MPO could be taken up by endothelium, NETs could be considered as a vascular memory of intermittent bioincompatibility phenomenon. In this working hypothesis article, we summarized the puzzle pieces showing the involvement of NET formation during hemodialysis and postulated that NETosis may act as a disease modifier and may contribute to the comorbid burden associated with dialysis bioincompatibility.

The effect of pomegranate consumption on cardiovascular risk factors in hemodialysis patients: A systematic review of clinical trials

Patients undergoing maintenance dialysis have a significantly higher incidence of cardiovascular disease (CVD) compared with the general population. CVD is the most common cause of morbidity and mortality among hemodialysis patients, and has been attributed, among other causes, to increased oxidative stress, inflammation, hypertension and dyslipidemia. Pomegranate, a popular fruit worldwide, has demonstrated health benefits such as antioxidative, antidiabetic, antihypertensive, antihyperlipidemic and anti-inflammatory effects. In this systematic review of clinical trials, we aim to summarize the effect of different parts of pomegranate and the effects of its use on CVD risk factors in hemodialysis patients. PubMed/MEDLINE, EMBASE, Scopus, and Web of Science were searched to identify eligible clinical trials up to December 2021. Ultimately, seven clinical trials were included in this study. Different parts of pomegranate used in these trials were pomegranate juice, pomegranate extract and pomegranate peel extract. The duration of the studies varied from one dialysis session to 1 year. Our results showed that different parts of pomegranate may have anti-hypertensive, antioxidant, anti-inflammatory effects and improve lipid profile by decreasing TG (triglycerides) and increasing HDL-C (high-density lipoprotein cholesterol) in hemodialysis patients. However, due to limited number of studies, more clinical trials need to be performed.

Delayed Graft Function Among Kidney Transplant Recipients Is Associated With an Increased Risk of Urinary Tract Infection and BK Viremia

BACKGROUND

Delayed graft function (DGF) among deceased donor kidney transplant recipients (DDKTRs) is a well-known risk factor for allograft rejection, decreased graft survival, and increased cost. Although DGF is associated with an increased risk of rejection, it is unclear whether it also increases the risk of infection.

METHODS

We reviewed all adult DDKTRs at our center between 2010 and 2018. The primary outcomes of interest were BK viremia, cytomegalovirus viremia, pneumonia, and urinary tract infection (UTI) within the first year of transplant. Additional analysis was made with censoring follow-up at the time of allograft rejection.

RESULTS

A total of 1512 DDKTRs were included, of whom 468 (31%) had DGF. As expected, several recipient, donor, and baseline immunological characteristics differed by DGF status. After adjustment, DGF was significantly associated with an increased risk of BK viremia (hazard ratio: 1.34; 95% confidence interval, 1.0-1.81; P = 0.049) and UTI (hazard ratio: 1.70; 95% confidence interval, 1.31-2.19; P < 0.001) but not cytomegalovirus viremia or pneumonia. Associations were similar in models censored at the time of rejection.

CONCLUSIONS

DGF is associated with an increased risk of early infectious complications, mainly UTI and BK viremia. Close monitoring and appropriate management are warranted for better outcomes in this unique population.

The relationship between dietary patterns derived from inflammation and cognitive impairment in patients undergoing hemodialysis

Introduction

Dietary patterns were shown to be closely related to inflammation, which was independently associated with cognitive impairment (CI) in patients undergoing hemodialysis (HD). However, it remains unclear the influence of dietary patterns derived from inflammation on CI in this population. This study aimed to examine the association between dietary patterns derived from C-reactive protein (CRP) and interleukin-6 (IL-6) and CI in patients undergoing HD.

Methods

Dietary intake was obtained from the simplified quantitative food frequency questionnaire. Reduced rank regression (RRR) was used to extract two dietary patterns, with IL-6 and CRP as response variables. Cognitive function was examined by the Montreal Cognitive Assessment (Beijing version). Venous blood was drawn for measuring IL-6 and CRP levels. Multivariable logistic regression was used to investigate the association between dietary patterns and CI.

Results

Dietary pattern derived from IL-6 was not significantly associated with CI. The third quartile of dietary pattern, which used CRP as the response variable, significantly contributed to the increased risk of CI (AOR 8.62, 95% CI 1.47-50.67) after controlling age, sex, education level, marital status, and residential pattern (p-for-trend = 0.028). After considering hypertension and diabetes, physical activity level, anxiety and depression, smoking and drinking status, social support, energy intake, and the dietary pattern derived from IL-6 (p-for-trend = 0.026), the relationship between the dietary pattern derived from CRP and CI remained significant (AOR 14.54, 95% CI 1.40-151.13).

Conclusion

Dietary pattern associated with high CRP level, including high intake of rice, liquor, fruit, tea and coffee and low intake of dark vegetables and juice, contributed to the increased risk of CI. The association between the consumption of seafood, sweet beverages, and alcohol and CI is yet to be established. However, they may be dietary contributing factors to inflammation in patients undergoing HD.

Pre-existing serum indoxyl sulfate and COVID-19 outcomes in patients undergoing hemodialysis: A retrospective cohort study

Patients undergoing hemodialysis (HD) are at increased risk of severe complications from COVID-19 due to compromised immune function and comorbidities. This retrospective study aimed to investigate the association between pre-existing serum indoxyl sulfate (IS) concentrations and COVID-19 outcomes in HD patients. Methods. Data on pre-existing IS and proinflammatory cytokines, such as interleukin-6 (IL-6), monocyte chemoattractant protein-1 (MCP-1), and tumor necrosis factor-alpha (TNF-α) were extracted from an existing patient database. The patients were followed up for 1.5 years and compared according to median serum IS concentration: low-IS (< 22.2 μg/mL) and high-IS (≥22.2 μg/mL) groups. The primary outcomes focused on assessing the risk and severity of COVID-19 infection. Results. A total of 56 patients aged 62 (56-67) years with a dialysis vintage of 37.5 (30-168) months were included in the analysis. Serum levels of IS were significantly correlated with Kt/V values (p = 0.043), arterial hypertension (p = 0.001), IL-6 (p = 0.023), MCP-1 (p = 0.023), and TNF-α (p = 0.033) concentrations. Elevated serum IS levels were significantly associated with an increased risk of COVID-19 infection (p < 0.0001) and a higher likelihood of hospitalization (p = 0.03). Patients with higher IS levels exhibited more severe lung involvement (p < 0.0001) and a greater need for respiratory support (p = 0.004). A serum IS concentration of 21.5 μg/mL was the optimal threshold for predicting COVID-19 infection in HD patients (sensitivity of 83.4% and specificity of 92.3%, p < 0.0001). Conclusion: Our study highlights the detrimental impact of serum IS on COVID-19 infection and its clinical outcomes in patients undergoing HD. Further research is warranted to elucidate the underlying mechanisms and explore potential therapeutic strategies targeting IS in this population.

Maintenance of Potent Cellular and Humoral Immune Responses in Long-Term Hemodialysis Patients after 1273-mRNA SARS-CoV-2 Vaccination

Continuous evaluation of the coronavirus disease 2019 (COVID-19) vaccine effectiveness in hemodialysis (HD) patients is critical in this immunocompromised patient group with higher mortality rates due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The response towards vaccination in HD patients has been studied weeks after their first and second SARS-CoV-2 vaccination dose administration, but no further studies have been developed in a long-term manner, especially including both the humoral and cellular immune response. Longitudinal studies that monitor the immune response to COVID-19 vaccination in individuals undergoing HD are therefore necessary to prioritize vaccination strategies and minimize the pathogenic effects of SARS-CoV-2 in this high-risk group of patients. We followed up HD patients and healthy volunteers (HV) and monitored their humoral and cellular immune response three months after the second (V2+3M) and after the third vaccination dose (V3+3M), taking into consideration previous COVID-19 infections. Our cellular immunity results show that, while HD patients and HV individuals secrete comparable levels of IFN-γ and IL-2 in ex vivo stimulated whole blood at V2+3M in both naïve and COVID-19-recovered individuals, HD patients secrete higher levels of IFN-γ and IL-2 than HV at V3+3M. This is mainly due to a decay in the cellular immune response in HV individuals after the third dose. In contrast, our humoral immunity results show similar IgG binding antibody units (BAU) between HD patients and HV individuals at V3+3M, independently of their previous infection status. Overall, our results indicate that HD patients maintain strong cellular and humoral immune responses after repeated 1273-mRNA SARS-CoV-2 vaccinations over time. The data also highlights significant differences between cellular and humoral immunity after SARS-CoV-2 vaccination, which emphasizes the importance of monitoring both arms of the immune response in the immunocompromised population.

Risk of Major Cardiovascular Disease after Exposure to Contrast Media: A Nationwide Population-Based Cohort Study on Dialysis Patients

Contrast associated kidney injury is caused by side effects of iodinated contrast media (ICM), including inflammation. Chronic inflammation among dialysis patient contributes to atherosclerosis, which leads to simultaneous conditions of the kidney, brain, and vasculature. Data to investigate the pathologic effects of ICM on cardiovascular complications in dialysis patients are lacking. Dialysis patients who had been exposed to ICM from computed tomography (ICM-CT) were allocated as the ICM-CT cohort (N = 3751), whereas dialysis patients without ICM exposure were randomly allocated as the non-ICM cohort (N = 17,196). Furthermore, 540 pairs were selected for analyses through propensity score-matching in terms of age, sex, comorbidities, dialysis vintage, and index date. During a median follow-up of 10.3 years, ICM-CT cohort had significantly higher risks in the following, compared with non-ICM cohort: all-cause mortality (adjusted hazard ratio [aHR], 1.36; 95% confidence interval [CI], 1.26-1.47), cardiovascular events (aHR,1.67; 95% CI, 1.39-2.01), acute coronary syndrome (adjusted HR: 2.92; 95% CI, 1.72-4.94), sudden cardiac arrest (aHR, 1.69; 95% CI, 0.90-3.18), heart failure (aHR, 1.71; 95% CI,1.28-2.27), and stroke (aHR, 1.84; 95% CI,1.45-2.35). The proinflammatory ICM is significantly associated with an increased risk of major cardiovascular events in patients on dialysis.

The Characteristics of Dialysis Membranes: Benefits of the AN69 Membrane in Hemodialysis Patients

Patients undergoing hemodialysis (HD) experience serious cardiovascular complications, through malnutrition, inflammation, and atherosclerosis. Amputation for peripheral arterial disease (PAD) is more prevalent in patients undergoing HD than in the general population. In addition, revascularization procedures in dialysis patients are often associated with subsequent amputation and high mortality rates. To improve the prognosis of dialysis patients, malnutrition and inflammation must be properly treated, which necessitates a better understanding of the characteristics of dialysis membranes. Herein, the characteristics of several dialysis membranes were studied, with a special reference to the AN69 membrane, noting several similarities to low-density lipoprotein (LDL)-apheresis, which is also applicable for the treatment of PAD. Both systems (LDL-apheresis and AN69) have anti-inflammatory and anti-thrombogenic effects because they use a negatively charged surface for extracorporeal adsorptive filtration from the blood/plasma, and contact phase activation. The concomitant use of both these therapeutic systems may have additive therapeutic benefits in HD patients. Here, we reviewed the characteristics of dialysis membranes and benefits of the AN69 membrane in dialysis patients.

Strategies to lower fibroblast growth factor 23 bioactivity

Fibroblast growth factor 23 (FGF23) is a circulating hormone derived from the bone whose release is controlled by many factors and exerts a multitude of systemic actions. There are congenital and acquired disorders of increased and decreased FGF23 levels. In chronic kidney disease (CKD), elevations of FGF23 levels can be 1000-fold above the upper physiological limit. It is still debated whether this high FGF23 in CKD is a biomarker or causally related to morbidity and mortality. Data from human association studies support pathogenicity, while experimental data are less robust. Knowledge of the biology and pathobiology of FGF23 has generated a plethora of means to reduce FGF23 bioactivity at many levels that will be useful for therapeutic translations. This article summarizes these approaches and addresses several critical questions that still need to be answered.

Immune System Dysfunction and Inflammation in Hemodialysis Patients: Two Sides of the Same Coin

Biocompatibility in hemodialysis (HD) has considerably improved in recent decades, but remains an open issue to be solved, appearing essential to reduce systemic inflammation and enhance patients’ clinical outcomes. Clotting prevention, reduction in complement and leukocyte activation, and improvement of antioxidant effect represent the main goals. This review aims to analyze the different pathways involved in HD patients, leading to immune system dysfunction and inflammation. In particular, we mostly review the evidence about thrombogenicity, which probably represents the most important characteristic of bio-incompatibility. Platelet activation is one of the first steps occurring in HD patients, determining several events causing chronic sub-clinical inflammation and immune dysfunction involvement. Moreover, oxidative stress processes, resulting from a loss of balance between pro-oxidant factors and antioxidant mechanisms, have been described, highlighting the link with inflammation. We updated both innate and acquired immune system dysfunctions and their close link with uremic toxins occurring in HD patients, with several consequences leading to increased mortality. The elucidation of the role of immune dysfunction and inflammation in HD patients would enhance not only the understanding of disease physiopathology, but also has the potential to provide new insights into the development of therapeutic strategies.

Association between periodontitis and chronic kidney disease

Periodontitis and chronic kidney disease are chronic conditions with high community prevalence across the world. Patients with chronic kidney disease have been noted to have a high burden of periodontitis, and several shared risk factors have been associated with the prevalence and severity of both conditions. However, the precise relationship between the two conditions, and the extent to which each may contribute to the development of the other, remains a matter of debate. The goals of the present work were to: (a) provide the most current and relevant literature overview of the association between periodontitis and chronic kidney disease; (b) explore mechanisms underlying this association; and (c) determine if evidence exists for an independent association between these conditions. We also assessed whether improved oral hygiene and periodontal treatment could reduce the risk of developing chronic kidney disease and, if so, what protocols these strategies involve. Finally, we aimed to reveal gaps in our current knowledge to delineate the directions of future research. Although the exact relationship between these two conditions has not yet been defined, we highlight the importance of the interprofessional interaction between dental practitioners and the nephrology team and the importance of oral health assessment in the management of chronic kidney disease.

The Myeloid-Kidney Interface in Health and Disease

Kidney homeostasis is highly dependent upon the correct functioning of myeloid cells. These cells form a distributed surveillance network throughout the kidney, where they play an integral role in the response to organ threat. Dysregulation of resident proinflammatory and profibrotic macrophages leads to kidney structural damage and scarring after kidney injury. Fibrosis throughout the kidney parenchyma contributes to the progressive functional decline observed in CKD, independent of the etiology. Circulating myeloid cells bearing intrinsic defects also affect the kidney substructures, such as neutrophils activated by autoantibodies that cause GN in ANCA-associated vasculitis. The kidney can also be affected by disorders of myelopoiesis, including myeloid leukemias (acute and chronic myeloid leukemias) and myelodysplastic syndromes. Clonal hematopoiesis of indeterminate potential is a common, newly recognized premalignant clinical entity characterized by clonal expansion of hyperinflammatory myeloid lineage cells that may have significant kidney sequelae. A number of existing therapies in CKD target myeloid cells and inflammation, including glucocorticoid receptor agonists and mineralocorticoid receptor antagonists. The therapeutic indications for these and other myeloid cell-targeted treatments is poised to expand as our understanding of the myeloid-kidney interface evolves.

Real-World Performance of High-Flux Dialyzers in Patients With Hypoalbuminemia

There is little research on factors that influence the choice of dialyzer in patients undergoing hemodialysis. In patients at risk for poorer outcomes, including those with hypoalbuminemia, understanding how this choice impacts clinical parameters could inform patient management. The objective of this real-world analysis was to evaluate the use and performance of four single-use (i.e., nonreuse [NR]), high-flux Optiflux dialyzers with varying surface areas (F160NR [1.5 m2], F180NR [1.7 m2], F200NR [1.9 m2], and F250NR [2.5 m2]) in patients (N = 271) with baseline hypoalbuminemia (≤3.5 g/dl) receiving hemodialysis at a medium-sized dialysis organization. Thrice weekly, in-center dialysis was delivered for 6 months without adjustments to the hemodialysis prescription. Larger dialyzers were more frequently used in men, patients with higher body mass indices, and those with diabetes. Increases in serum albumin from baseline (month 1) to month 6 (p < 0.05) were observed with all dialyzer sizes. A mean increase in hemoglobin of 0.31 g/dl was also observed (p < 0.001). Among patients exhibiting increased serum albumin levels (n = 177), reductions in the neutrophil-to-lymphocyte ratio, a marker of inflammation, were observed (mean: 0.90; p < 0.001). These results support the use of high-flux dialyzers in patients with hypoalbuminemia.

Comparison of Inflammatory Markers in the Diagnosis of Metabolic Syndrome in Hemodialysis Patients: A Multicenter Observational Study

OBJECTIVE

The purpose of this study is to observe the correlation between high sensitivity C-reactive protein (hs-CRP) and metabolic syndrome (MetS) in hemodialysis patients, determine its optimal cut-off point value, and compare the diagnostic ability of different inflammatory markers for MetS.

METHODS

This cross-sectional study finally included 860 long-term hemodialysis patients (male 524, average age 61.5 years) from seven dialysis centers in Shanghai, China. The International Diabetes Federation metabolic syndrome guidelines were used to define MetS, including high waist circumference, elevated blood pressure, elevated fasting blood glucose, elevated triglycerides, and reduced HDL cholesterol. Serum hs-CRP was determined by the immunonephelometric assay. The association with MetS was observed according to the quartile of inflammatory markers, and then the optimal cut-off point value of the hs-CRP was determined by ROC analysis.

RESULTS

The overall prevalence of MetS was 55.1% (46.6% in males and 68.5% in females). In the final logistic regression model, there was a significant, graded positive association between hs-CRP and MetS (p for trend = 0.010). The traditional inflammatory markers leukocytes, neutrophils, lymphocytes, monocytes and neutrophil-to-lymphocyte ratio (NLR) were not associated with MetS. The results of the ROC analysis showed that the optimal cut point value of hs-CRP for the diagnosis of MetS was 1.58 mg/L. In the components of MetS and hs-CRP was significantly positively associated with high waist circumference, elevated TG and low HDL (p < 0.05).

CONCLUSION

The increase in hs-CRP concentration is significantly associated with the risk of MetS, and the diagnostic ability of hs-CRP for MetS is better than traditional inflammatory markers.

Fatigue and apathy in patients on chronic hemodialysis

INTRODUCTION

This study explores the link between fatigue and apathy in patients on chronic hemodialysis (HD).

METHODS

One hundred thirty-nine chronic HD patients underwent the assessment of fatigue, apathy, depression, and their functional status, with the fatigue severity scale (FSS), the Apathy Evaluation Scale (AES), the beck depression inventory (BDI), the activity of daily living (ADL), and instrumental activity of daily living (IADL).

RESULTS

Patients with high FSS had a significantly lower ADL and IADL score, higher BDI, Charlson Comorbidity Index, and AES score, and lower serum levels of creatinine, compared to low FSS patients. FSS was highly correlated with the AES, as well as with the BDI and the AES correlates with the BDI. At multiple regression analyses, only apathy and IADL were independent predictor variables of fatigue in HD population.

CONCLUSION

Future longitudinal studies could determine if apathy is a causative factor for fatigue manifestation and development in HD patients.

Chronic Kidney Disease and Arterial Stiffness: A Two-Way Path

The kidney-heart relationship has raised interest for the medical population since its vast and complex interaction significantly impacts health. Chronic kidney disease (CKD) generates vascular structure and function changes, with significant hemodynamic effects. The early arterial stiffening in CKD patients is a consequence of the interaction between oxidative stress and chronic vascular inflammation, leading to an accelerated deterioration of left ventricular function and alteration in tissue perfusion. CKD amplifies the inflammatory cascade's activation and is responsible for altering the endothelium function, increasing the vascular tone, wall thickening, and favors calcium deposits in the arterial wall. Simultaneously, the autonomic imbalance, and alteration in other hormonal systems, also favor the overactivation of inflammatory and fibrotic mediators. Thus, hormonal disarrangement also contributes to structural and functional lesions throughout the arterial wall. On the other hand, a rise in arterial stiffening and volume overload generates high left ventricular afterload. It increases the left ventricular burden with consequent myocardial remodeling, development of left ventricular hypertrophy and, in turn, heart failure. It is noteworthy that reduction in glomerular mass of renal diseases generates a compensatory glomerular filtration overdriven associated with large-arteries stiffness and high cardiovascular events. Furthermore, we consider that the consequent alterations of the arterial system's mechanical properties are crucial for altering tissue perfusion, mainly in low resistance. Thus, increasing the knowledge of these processes may help the reader to integrate them from a pathophysiological perspective, providing a comprehensive idea of this two-way path between arterial stiffness and renal dysfunction and their impact at the cardiovascular level.

Is malnutrition a determining factor of health-related quality of life in hemodialysis patients? A cross-sectional design examining relationships with a comprehensive assessment of nutritional status

PURPOSE

To identify relationships between health-related quality of life (HRQOL) and nutritional status in hemodialysis (HD) patients.

METHOD

Secondary data from a cross-sectional survey was utilized. HRQOL was assessed for 379 HD patients using the generic Short Form 36 (SF-36) and disease-specific Kidney-Disease Quality of Life-36 (KDQOL-36). Malnutrition was indicated by malnutrition inflammation score (MIS) ≥ 5, and presence of protein-energy wasting (PEW). The individual nutritional parameters included the domains of physical status, serum biomarkers, and dietary intake. Multivariate associations were assessed using the general linear model.

RESULTS

MIS ≥ 5 was negatively associated with SF-36 scores of physical functioning (MIS < 5 = 73.4 ± 8.0 SE vs MIS ≥ 5 = 64.6 ± 7.7 SE, P < 0.001), role-limitation-physical (MIS < 5 = 65.3 ± 14.3 SE vs MIS ≥ 5 = 52.9 ± 14.0 SE, P = 0.006), general health (MIS < 5 = 53.7 ± 7.5 SE vs MIS ≥ 5 = 47.0 ± 7.1 SE, P = 0.003), and PCS-36 (MIS < 5 = 40.5 ± 3.3 SE vs MIS ≥ 5 = 35.9 ± 3.1 SE, P < 0.001); and KDQOL-36 score of symptoms/problems (MIS < 5 = 78.9 ± 5.6 SE vs MIS ≥ 5 = 74.8 ± 5.4 SE, P = 0.022), but not with PEW by any tool. Of individual nutritional parameters, underweight (68.1 ± 5.4 SE, P = 0.031), normal weight (63.8 ± 2.8 SE, P = 0.023), and overweight (64.3 ± 2.9 SE, P = 0.003) patients had significantly higher physical functioning scores compared to obese patients (44.8 ± 5.5 SE). Serum albumin levels were positively associated with physical functioning (P = 0.041) score. HGS was also positively associated with physical functioning (P = 0.036), and vitality (P = 0.041) scores. Greater dietary phosphorus intakes were significantly associated with lower scores for role limitation-physical (P = 0.008), bodily pain (P = 0.043), and PCS-36 (P = 0.024).

CONCLUSION

Malnutrition diagnosis by MIS, but not PEW, indicated associations with HRQOL in HD patients. Individual nutritional parameters that related to higher HRQOL were BMI < 30 kg/m², better dietary phosphorus control, greater muscle strength and higher visceral protein pool.

Creatinine generation rate can detect sarcopenia in patients with hemodialysis

BACKGROUND

Sarcopenia is strongly associated with long-term mortality in patients undergoing hemodialysis. The diagnostic modalities used to assess muscle mass, such as bioimpedance analysis and dual-energy X-ray absorption measurement, have limitations for application in patients on hemodialysis. Therefore, there is a need to establish a simple index for assessing muscle mass that can be universally performed in patients on hemodialysis.

METHODS

Patients on maintenance hemodialysis were included in this study. Laboratory tests, skeletal muscle mass measured by bioimpedance analysis, and clinical records were obtained retrospectively. The creatinine generation rate (CGR) was calculated from the pre- and postdialysis blood tests using a kinetic model as the index for whole-body muscle mass. Correlations between the CGR and skeletal muscle mass were investigated, and the cut-off value for muscle wasting was determined. Kaplan-Meier survival analysis was performed to investigate the feasibility of the CGR for predicting long-term survival.

RESULTS

Among the 130 patients included, eight were diagnosed with sarcopenia by bioimpedance analysis. The CGR was positively correlated with skeletal muscle mass (r = 0.454, p < 0.001). Multiple linear regression analysis revealed that age and sex independently influenced the CGR. The patients were classified into two groups according to age- and sex-adjusted CGRs. During a median follow-up period of 32 months, the Kaplan-Meier survival analysis showed that patients with low CGR showed significantly poor long-term prognosis (p = 0.002).

CONCLUSION

The CGR is a simple index for muscle mass and can predict long-term mortality in patients on hemodialysis.

Cytokines and chemokines systemic levels are related to dialysis adequacy and creatinine clearance in patients with end-stage renal disease undergoing hemodialysis

Although the clearance of low-molecular weight toxins is modulated by dialysis dose, the relationship between dialysis adequacy and middle systemic inflammatory mediators is often overlooked. Thus, the relationship between dialysis adequacy, pro- and anti-inflammatory cytokines and chemokines in hemodialysis (HD) patients was investigated. Forty-eight HD patients (19 women and 25 men) were investigated. Age, body mass index, time in HD, nutritional status, Kt/V and blood biochemical parameters was similar in patients of both sexes (P > 0.05). Thus, patients were stratified by dialysis adequacy measured by Kt/V method (adequate Kt/V ≥ 1.2). Post-HD urea, creatinine, cytokines (IFN-γ, IL-4 and IL-10) and chemokines (CCL-2, CCL-5, CXCL-8 and CXCL-10) were higher in patients with Kt/V < 1.2 (P < 0.05). Kt/V exhibited significant correlation with CXCL-10/IP-10 serum levels. Positive correlation between creatinine with IFN-γ, CCL-2/MCP-1, and CXCL-10/IP-10, and negative correlation with IL-10 was identified in patients with Kt/V < 1.2 (P < 0.05). In patients with Kt/V ≥ 1.2, only IL-10 was positively and CXCL-10/IP-10 negatively correlated with creatinine levels (P < 0.05). Kt/V and creatinine levels exhibited variable predictive value (Kt/V = 27% to 37%, creatinine = 29% to 47%) to explain cytokines and chemokines circulating levels in patients with adequate and inadequate dialysis dose. Taken together, our findings provide evidence that in addition to modulating uremic toxins levels, such as urea and creatinine, dialysis dose is associated with circulating levels of inflammatory mediators. Thus, low Kt/V results and creatinine accumulation are potential indicators of the systemic inflammatory stress determined by up-regulation of proinflammatory cytokines and chemokines, and downregulation of anti-inflammatory cytokines.

C-X-C Motif Chemokine Ligand 16 Is a Potent Predictor of Outcomes in Dialysis Patients

INTRODUCTION

C-X-C motif chemokine ligand 16 (CXCL16) is an inflammatory marker that has been found to be predictive of outcomes in patients with cardiovascular disease. Our previous work has also demonstrated its relation to cardiac injury in dialysis patients. However, it is yet unclear whether there is an association between CXCL16 and adverse outcomes in dialysis patients. We aimed to evaluate its prognostic value along with several traditional inflammatory markers in the current study.

METHODS

This is a multicenter longitudinal study of prevalent dialysis patients. Circulating inflammatory markers including CXCL16, C-reactive protein (CRP), tumor necrosis factor-α, and interleukin-6 (IL-6) were measured using a multiplex assay. The primary outcomes were all-cause mortality and a composite of major adverse cardiovascular events (MACEs). The associations between biomarkers and outcomes were analyzed using Cox proportional hazards regression models.

RESULTS

Of the 366 participants with available plasma samples, the average age was 52.5 (±12.1) years, and there were 160 (43.7%) female participants. For all-cause mortality, logarithmically transformed CXCL16, IL-6, and CRP were independent predictors after adjustment for covariates. When the 3 markers were included in the same model, CXCL16 was the only one remaining its significance. For MACEs, logarithmically transformed CXCL16 and IL-6 were significant predictors when analyzed separately and CXCL16 was an independent predictor even after adjustment for IL-6. When the biomarkers were analyzed as categorical variables, only CXCL16 was associated with both outcomes. Adding CXCL16 to established risk factors improved risk prediction as revealed by Net Reclassification Index (NRI).

CONCLUSION

Using a multimarker approach, we determined that CXCL16 is a potent predictor of all-cause mortality and cardiovascular events in dialysis patients. Our data suggest CXCL16 may improve risk stratification and could be a potential interventional target.

Uremic Toxins and Cardiovascular System

When chronic kidney disease develops, the capacity of the kidneys to clear metabolic waste products from the body is gradually lost. This process results in the retention of a large array of compounds affecting biochemical and biological functions (uremic toxins), of which several can cause cardiovascular damage. This article reviews the main cardiotoxic mechanisms related to uremic toxin retention (endothelial dysfunction, vascular smooth muscle cell alterations, inflammation, mineral bone disorder, insulin resistance, and thrombogenicity) and the main responsible retention compounds. Therapeutic options are reviewed, such as influencing solute generation by intestinal microbiota.

Inflammation-based modified Glasgow prognostic score and renal outcome in chronic kidney disease patients: is there a relationship?

BACKGROUND

Chronic kidney disease (CKD) progression is presumably related to inflammatory response. The modified Glasgow prognostic score (mGPS), based on combination between albumin and C-reactive protein, has been derived from oncology and validated in multiple diseases.

AIMS

We aimed to evaluate the relationship between the mGPS and CKD progression.

METHODS

The present retrospective unicentric cohort study included 547 CKD patients (age 60.2 years, 53% male, eGFR 42.0 mL/min, mean change -2 mL/min/year) admitted between January 1, 2007 and December 31, 2012. Patients records were reviewed from the CKD diagnosis to one of the four outcomes: end-stage kidney disease (ESKD), death, loss to follow-up, or until July 31, 2017.

RESULTS

The mGPS score was 0 for 420 (78%), 1 for 110 (19%), and 2 for 17 (3%) patients. More patients with rapid CKD progression were found in the group with the highest mGPS (p=0.05). mGPS was negatively correlated with baseline eGFR and positively with albuminuria. In the multivariate analysis, mGPS was associated with the eGFR slope. During the study period, 130 patients (24%) died and 109 (20%) reached ESKD. The mean kidney survival time was 8.1 (95%CI 7.9 to 8.4) years. Patients with zero mGPS had better kidney survival than those with the score of one and two (Kaplan-Meier, p=0.02). However, the kidney survival differences were not present after adjusting for CKD progression risk factors.

CONCLUSION

The inflammation-based mGPS score was associated with eGFR decline in CKD patients. Therefore, could prove useful in improving risk stratification of CKD patients. This article is protected by copyright. All rights reserved.

The Gamma Gap Predicts All-Cause Mortality in Chronic Dialysis Patients

Introduction:

The gamma gap (γ-gap) represents the total serum protein concentration minus the albumin concentration. The main aim of this study was to test whether the gamma gap is a predictor of mortality and whether it is associated with other predictors of mortality in chronic hemodialysis patients (CHPs).

Materials and Methods:

We studied a cohort of 100 CHPs with a mean age of 59 ± 12.3 years with duration of dialysis 6.5 ± 4.7 years. Serum proteins were determined by electrophoresis. The association of the gamma gap with serum C-reactive protein (CRP), fibrinogen and albumin concentration was evaluated for correlation. Cox regression analysis was used to identify the predictors of mortality.

Results:

The γ-gap correlates positively with CRP (r = 0.247, P = 0.013) and fibrinogen (r = 0.239, P = 0.016), and inversely with albumin (r = -0.430, P < 0.0001). The regression coefficients (b) and Exp (b) hazard ratio coefficients of covariates in Cox-regression survival analysis in all-cause outcomes were: b = 0.1486, Exp (b) = 1.1602 (P < 0.0001); b = 0.0655, Exp (b) = 1.0677 (P < 0.0015) and b = -0.118, Exp (b) = 0.8887 (P < 0.0009), for γ-gap, CRP and albumin, respectively.

Conclusions:

In patients on chronic hemodialysis, the gamma gap, along with serum albumin and CRP levels, is an independent predictor of mortality. Gamma gap levels correlate directly with serum CRP and fibrinogen levels and inversely with serum albumin levels.

Expanded Hemodialysis and Its Effects on Hospitalizations and Medication Usage: A Cohort Study

INTRODUCTION

Expanded hemodialysis (HDx) effectively removes large middle molecular uremic toxins (>25 kDa) while still retaining albumin, potentially reducing their adverse effects. We compare the clinical laboratory parameters, hospitalization rates, and medication use in a cohort of patients switched from high-flux HD to HDx.

METHODS

This is a multicenter, observational cohort study of 81 adult patients, across 3 clinics, with end-stage kidney disease (ESKD) on chronic hemodialysis (HD). Patients received high-flux HD for at least 1 year and then switched to HDx and were followed up for 1 year. Patients were excluded if they discontinued therapy, changed provider, underwent kidney transplant, recovered kidney function, or changed to peritoneal dialysis, another dialyzer, or renal clinic.

RESULTS

Twelve months after switching to HDx, the rate of hospitalization events per patient-year decreased from 0.77 (95% CI: 0.60-0.98, 61 events) to 0.71 (95% CI: 0.55-0.92, 57 events) (p = 0.6987). The hospital day rate per patient-year was significantly reduced from 5.94 days in the year prior to switching compared with 4.41 days after switching (p = 0.0001). The mean dose of erythropoiesis-stimulating agent (SC epoetin-α) and intravenous iron also significantly decreased (p = 0.0361 and p = 0.0003, respectively).

CONCLUSION

Switching to HDx was associated with reductions in hospital day rate and medication use, suggesting HDx has the potential to reduce the burden of ESKD on patients and healthcare systems.

Obesity and Other Nutrition Related Abnormalities in Pre-Dialysis Chronic Kidney Disease (CKD) Participants

Chronic kidney disease (CKD) is increasing in sub-Saharan Africa. Undernutrition has been prevalent amongst end stage CKD patients, with limited data on the prevalence of obesity. The aim of this study was to assess the nutritional status of CKD patients using various methods sensitive to over and under-nutrition. Stage 3 to 5 CKD patients (glomerular filtration rate (GFR) < 60 mL/min/1.73 m2) attending a pre-dialysis clinic in Cape Town, were enrolled. Exclusion criteria included infectious and autoimmune conditions. Sociodemographic, clinical and biochemical data were collected, and anthropometric measurements were performed. Dietary intake was measured with a quantified food frequency questionnaire (FFQ). Statistical Package for the Social Sciences (SPSS) version 26 was used for statistical analysis. Seventy participants, with mean age of 41.8 ± 11.8 years, 52.9% females and 47.1% males were enrolled. Participants enrolled mainly had stage 5 kidney failure. Thirty percent were overweight (21) and 25 (36%) were obese, 22 (60%) of females were overweight and obese, while 13 (39.4%) of males were predominantly normal weight. Abdominal obesity was found in 42 (60%) of participants, mainly in females. Undernutrition prevalence was low at 3%. Dietary assessment showed a high sugar and protein intake. There was a high prevalence of overweight, obesity and abdominal obesity in CKD stage 35 patients, with unhealthy dietary intake and other nutritional abnormalities.

Glycemic Monitoring and Management in Advanced Chronic Kidney Disease

Glucose and insulin metabolism in patients with diabetes are profoundly altered by advanced chronic kidney disease (CKD). Risk of hypoglycemia is increased by failure of kidney gluconeogenesis, impaired insulin clearance by the kidney, defective insulin degradation due to uremia, increased erythrocyte glucose uptake during hemodialysis, impaired counterregulatory hormone responses (cortisol, growth hormone), nutritional deprivation, and variability of exposure to oral antihyperglycemic agents and exogenous insulin. Patients with end-stage kidney disease frequently experience wide glycemic excursions, with common occurrences of both hypoglycemia and hyperglycemia. Assessment of glycemia by glycated hemoglobin (HbA1c) is hampered by a variety of CKD-associated conditions that can bias the measure either to the low or high range. Alternative glycemic biomarkers, such as glycated albumin or fructosamine, are not fully validated. Therefore, HbA1c remains the preferred glycemic biomarker despite its limitations. Based on observational data for associations with mortality and risks of hypoglycemia with intensive glycemic control regimens in advanced CKD, an HbA1c range of 7% to 8% appears to be the most favorable. Emerging data on the use of continuous glucose monitoring in this population suggest promise for more precise monitoring and treatment adjustments to permit fine-tuning of glycemic management in patients with diabetes and advanced CKD.

Effects of pomegranate peel extract and vitamin E on the inflammatory status and endothelial function in hemodialysis patients: a randomized controlled clinical trial

Inflammation and endothelial dysfunction are major problems in hemodialysis (HD) patients. This study assessed the effects of an 8 week administration of pomegranate peel extract (PPE) and vitamin E (Vit E) alone or in combination on the biomarkers of inflammation, including C-reactive protein (CRP), interleukin-6 (IL-6), and tumor necrosis factor-alpha (TNF-α), and the biomarkers of endothelial function, including intercellular adhesion molecule-1 (ICAM-1), vascular cell adhesion molecule-1 (VCAM-1), and P-selectin, in HD patients. In a randomized, double-blind, parallel, placebo-controlled trial, 100 HD patients were randomly divided into 4 equal groups: (a) PPE + Vit E, received 2 pomegranate tablets (each tablet contained 225 mg PPE, equal to 90 mg ellagic acid) + 1 Vit E soft gel (400 IU) daily, (b) PPE, received 2 pomegranate tablets + 1 Vit E placebo soft gel daily, (c) Vit E, received 1 Vit E soft gel + 2 pomegranate placebo tablets daily, and (d) placebo, received 2 pomegranate placebo tablets + 1 Vit E placebo soft gel daily. For group allocation, a stratified block randomization procedure based on sex, age, and HD duration was used. Each intervention product and its placebo had identical shape, color, size, and packaging. Consumption of PPE + Vit E significantly reduced the serum CRP level (mean change: -7.12 ± 4.59 mg l-1, P < 0.001) compared to other groups, while reduced levels of IL-6 (mean change: -2.19 ± 2.33 pg ml-1, P < 0.001), TNF-α (mean change: -2.41 ± 3.21 pg ml-1, P = 0.008), ICAM-1 (mean change: -64.2 ± 111.0 ng ml-1, P = 0.017), and VCAM-1 (mean change: -117.7 ± 177.1 ng ml-1, P = 0.002) were observed compared to the control. There was no significant difference in the P-selectin level among the groups. Consumption of PPE or Vit E alone significantly reduced the CRP level (mean change for PPE: -3.58 ± 5.41 mg l-1, P < 0.001; mean change for Vit E: -3.25 ± 8.29 mg l-1, P = 0.002) compared to the control. As a result, consumption of PPE in combination with Vit E enhanced the inflammatory status and endothelial function in HD patients.

Associations between Cell-Free Mitochondrial DNA and Inflammation, and Their Clinical Implications for Patients on Hemodialysis: A Prospective Multicenter Cohort Study

BACKGROUND

Cell-free mitochondrial DNA (cf-mtDNA) has recently been in the spotlight as an endogenously produced danger molecule that can potentially elicit inflammation. However, its clinical and prognostic implications are uncertain in patients undergoing hemodialysis.

METHODS

We examined the association of baseline cf-mtDNA categorized as tertiles with health-related quality of life (HRQOL), inflammatory cytokines, and mortality in a multicenter prospective cohort of 334 patients on hemodialysis. To better understand cf-mtDNA-mediated inflammation, we measured cytokine production after in vitro stimulation of bone marrow-derived macrophages (BMDMs) with mtDNA.

RESULTS

The higher cf-mtDNA tertile had a longer dialysis vintage, a greater comorbidity burden, and increased levels of inflammatory markers, including high-sensitivity-C-reactive protein, tumor necrosis factor-alpha, CXCL16, and osteoprotegerin. In particular, mtDNA augmented inflammatory cytokine release from BMDMs by lipopolysaccharide, the levels of which are reported to be increased in hemodialysis patients. Although the patients with higher levels of cf-mtDNA generally had lower (poorer) scores for HRQOL, cf-mtDNA was not associated with all-cause mortality in hemodialysis patients.

CONCLUSION

cf-mtDNA was correlated with poor clinical status and modestly associated with impaired quality of life in patients on hemodialysis. In proinflammatory milieu in end-stage renal disease, these associations may be attributed to the boosting effects of cf-mtDNA on inflammation.

Inflammation and Erythropoiesis-Stimulating Agent Response in Hemodialysis Patients: A Self-matched Longitudinal Study of Anemia Management in the Dialysis Outcomes and Practice Patterns Study (DOPPS)

Rationale & Objective

Previous studies of inflammation and anemia management in hemodialysis (HD) patients may be biased due to patient differences. We used a self-matched longitudinal design to test whether new inflammation, defined as an acute increase in C-reactive protein (CRP) level, reduces hemoglobin response to erythropoiesis-stimulating agent (ESA) treatment.

Study Design

Self-matched longitudinal design.

Setting & Participants

3,568 new inflammation events, defined as CRP level > 10 mg/L following a 3-month period with CRP level ≤ 5 mg/L, were identified from 12,389 HD patients in the Dialysis Outcomes and Practice Patterns Study (DOPPS) phases 4 to 6 (2009-2018) in 10 countries in which CRP is routinely measured.

Predictor

“After” (vs “before”) observing a high CRP level.

Outcomes

Within-patient changes in hemoglobin level, ESA dose, and ESA hyporesponsiveness (hemoglobin < 10 g/dL and ESA dose > 6,000 [Japan] or >8,000 [Europe] U/wk).

Analytical Approach

Linear mixed models and modified Poisson regression.

Results

Comparing before with after periods, mean hemoglobin level decreased from 11.2 to 10.9 g/dL (adjusted mean change, −0.26 g/dL), while mean ESA dose increased from 6,320 to 6,960 U/wk (adjusted relative change, 8.4%). The prevalence of ESA hyporesponsiveness increased from 7.6% to 12.3%. Both the unadjusted and adjusted prevalence ratios of ESA hyporesponsiveness were 1.68 (95% CI, 1.48-1.91). These associations were consistent in sensitivity analyses varying CRP thresholds and were stronger when the CRP level increase was sustained over the 3-month after period.

Limitations

Residual confounding by unmeasured time-varying risk factors for ESA hyporesponsiveness.

Conclusions

In the 3 months after HD patients experienced an increase in CRP levels, hemoglobin levels declined quickly, ESA doses increased, and the prevalence of ESA hyporesponsiveness increased appreciably. Routine CRP measurement could identify inflammation as a cause of worsened anemia. In turn, these findings speak to a potentially important role for anemia therapies that are less susceptible to the effects of inflammation.

Aortic stenosis in patients with kidney failure: Is there an advantage for a PD-first policy?

Aortic stenosis (AS) is the most common valvular disease. It is twice as prevalent in patients with kidney failure as compared to the general population. In addition, AS progresses at a faster rate and is associated with a higher risk of death and poorer quality of life in patients on dialysis. Chronic kidney disease–mineral and bone disorder (CKD-MBD), inflammation, and hemodynamic disturbances contribute to the pathophysiology and progression of AS. Whether the type of dialysis modality, that is, hemodialysis (HD) versus peritoneal dialysis (PD), has a differential impact on the development and progression of AS in patients with kidney failure remains debated. Recent data indicate that the prevalence of valvular calcifications might be lower and the development of AS delayed in PD patients, as compared to those treated with HD. This could be accounted for by several mechanisms including reduced valvular shear stress, better preservation of residual kidney function (with better removal of protein-bound uremic toxins and CKD-MBD profile), and lower levels of systemic inflammation. Given the high morbidity and mortality rates related to interventional procedures in the population with kidney failure, surgical and transcatheter aortic valve replacement should be considered in selected patients with severe AS. Strategies slowing down the progression of aortic valve remodeling should remain the cornerstone in the management of individuals with kidney failure and mild to moderate AS. This review explores the potential benefits of PD in patients with kidney failure and AS and provides some clues to help clinicians in the decision-making process when options for kidney replacement therapy are considered in patients with AS.

Phosphate Binders and Nonphosphate Effects in the Gastrointestinal Tract

Phosphate binders are commonly prescribed in patients with end-stage kidney disease to prevent and treat hyperphosphatemia. These binders are usually associated with gastrointestinal distress, may bind molecules other than phosphate, and may alter the gut microbiota, altogether having systemic effects unrelated to phosphate control. Sevelamer is the most studied of the available binders for nonphosphate-related effects including binding to bile acids, endotoxins, gut microbiota-derived metabolites, and advanced glycation end products. Other binders (calcium- and noncalcium-based binders) may bind vitamins, such as vitamin K and folic acid. Moreover, the relatively new iron-based phosphate binders may alter the gut microbiota, as some of the iron or organic ligands may be used by the gastrointestinal bacteria. The objective of this narrative review is to provide the current evidence for the nonphosphate effects of phosphate binders on gastrointestinal function, nutrient and molecule binding, and the gut microbiome.