Clinical relevance of cytokine production in hemodialysis

Aminolysis-Based Zwitterionic Immobilization on Polyethersulfone Membranes for Enhanced Hemocompatibility: Experimental, Computational, and Ex Vivo Investigations

Dialysis membranes are not hemocompatible with human blood, as the patients are suffering from the blood-membrane interactions' side effects. Zwitterionic structures have shown improved hemocompatibility; however, their complicated synthesis hinders their commercialization. The goal of the study is to achieve fast functionalization for carboxybetaine and sulfobetaine zwitterionic immobilization on PES membranes while comparing the stability and the targeted hemocompatibility. The chemical modification approach is based on an aminolysis reaction. Characterization, computational simulations, and clinical analysis were conducted to study the modified membranes. Atomic force microscopy (AFM) patterns showed a lower mean roughness for carboxybetaine-modified (6.3 nm) and sulfobetaine-modified (7.7 nm) membranes compared to the neat membrane (52.61 nm). The pore size of the membranes was reduced from values above 50 nm for the neat PES to values between 2 and 50 nm for zwitterionized membranes, using Brunauer-Emmett-Teller (BET) analysis. More hydrophilic surfaces led to a growth equilibrium water content (EWC) of nearly 6% for carboxybetaine and 10% for sulfobetaine-modified membranes. Differential scanning calorimetry (DSC) measurements were 12% and 16% stable water for carboxybetaine- and sulfobetaine-modified membranes, respectively. Sulfobetaine membranes showed better compatibility with blood with respect to C5a, IL-1a, and IL-6 biomarkers. Aminolysis-based zwitterionization was found to be suitable for the improvement of hemodialysis membranes. The approach introduced in this paper could be used to modify the current dialysis membranes with minimal change in the production facilities.

Interleukin-16 is increased in dialysis patients but is not a cardiovascular risk factor

Oxalate, a uremic toxin that accumulates in dialysis patients, is associated with cardiovascular disease. As oxalate crystals can activate immune cells, we tested the hypothesis that plasma oxalate would be associated with cytokine concentrations and cardiovascular outcomes in dialysis patients. In a cohort of 104 US patients with kidney failure requiring dialysis (cohort 1), we measured 21 inflammatory markers. As IL-16 was the only cytokine to correlate with oxalate, we focused further investigations on IL-16. We searched for associations between concentrations of IL-16 and mortality and cardiovascular events in the 4D cohort (1255 patients, cohort 2) and assessed further associations of IL-16 with other uremic toxins in this cohort. IL-16 levels were positively correlated with pOx concentrations (ρ = 0.39 in cohort 1, r = 0.35 in cohort 2) and were elevated in dialysis patients when compared to healthy individuals. No significant association could be found between IL-16 levels and cardiovascular events or mortality in the 4D cohort. We conclude that the cytokine IL-16 correlates with plasma oxalate concentrations and is substantially increased in patients with kidney failure on dialysis. However, no association could be detected between IL-16 concentrations and cardiovascular disease in the 4D cohort.

Heparin-Immobilized Polyethersulfone for Hemocompatibility Enhancement of Dialysis Membrane: In Situ Synchrotron Imaging, Experimental, and Ex Vivo Studies

The goal of the current study is to enhance the hemocompatibility of polyethersulfone (PES) membranes using heparin immobilization. Heparin was immobilized covalently and via electrostatic interaction with the positively charged PES surface (pseudo-zwitterionic (pZW) complex) to investigate the influence of each method on the membrane hemocompatibility. In situ synchrotron radiation micro-computed tomography (SR-µCT) imaging, available at the Canadian Light Source (CLS), was used to critically assess the fibrinogen adsorption to the newly synthesized membranes qualitatively and quantitatively using an innovative synchrotron-based X-ray tomography technique. The surface roughness of the synthesized membranes was tested using atomic force microscopy (AFM) analysis. The membrane hemocompatibility was examined through the ex vivo clinical interaction of the membranes with patients' blood to investigate the released inflammatory biomarkers (C5a, IL-1α, IL-1β, IL-6, vWF, and C5b-9). The presence and quantitative analysis of a stable hydration layer were assessed with DSC analysis. Surface modification resulted in reduced surface roughness of the heparin-PES membrane. Both types of heparin immobilization on the PES membrane surface resulted in a decrease in the absolute membrane surface charge from -60 mV (unmodified PES) to -13 mV for the pZW complex and -9.16 mV for the covalently attached heparin, respectively. The loss of human serum fibrinogen (FB) was investigated using UV analysis. The PES membrane modified with the heparin pseudo-ZW complex showed increased FB retention (90.5%), while the unmodified PES membrane and the heparin covalently attached PES membrane exhibited approximately the same level of FB retention (81.3% and 79.8%, respectively). A DSC analysis revealed an improvement in the content of the hydration layer (32% of non-freezable water) for the heparin-coated membranes compared to the unmodified PES membrane (2.84%). An SR-µCT analysis showed that the method of heparin immobilization significantly affects FB adsorption distribution across the membrane thickness. A quantitative analysis using SR-µCT showed that when heparin is attached covalently, FB tends to be deposited inside the membrane pores at the top (layer index 0-40) membrane regions, although its content peak distribution shifted to the membrane surface, whereas the unmodified PES membrane holds 90% of FB in the middle (layer index 40-60) of the membrane. The ex vivo hemocompatibility study indicates an improvement in reducing the von Willebrand factor (vWF) for the heparin pseudo-ZW PES membrane compared to the covalently attached heparin and the untreated PES.

Association between Chronic Kidney Disease and Sudden Sensorineural Hearing Loss: A Longitudinal Follow-Up Studies Using ICD-10 Codes in a National Health Screening Cohort

This study aims to investigate the association between chronic kidney disease (CKD) and sudden sensorineural hearing loss (SSNHL) using a population-based cohort study. We used data from the Korean National Health Insurance Service-Health Screening Cohort. Participants were selected based on diagnosis and treatment codes, and CKD participants were 1:4 matched with control participants. Covariates, including demographic and lifestyle factors, and comorbidities were considered in the analysis. We calculated the incidence rate and hazards ratio of SSNHL. A total of 16,713 CKD participants and 66,852 matched controls were enrolled. The CKD group had a higher incidence rate of SSNHL compared to the control group at 2.16 and 1.74 per 1000 person-years, respectively. The CKD group exhibited a higher risk for SSNHL compared to the control group with adjusted HR 1.21. In the subgroup analysis, the presence of cardiovascular risk factors was associated with a diminished effect of CKD on the risk of developing SSNHL. This study provides strong evidence of an association between CKD per se and an increased risk of SSNHL even after adjusting for various demographic and comorbidity factors. The findings suggest that CKD patients may require more comprehensive monitoring for hearing loss.

Exercise and chronic kidney disease: potential mechanisms underlying the physiological benefits

Increasing evidence indicates that exercise has beneficial effects on chronic inflammation, cardiorespiratory function, muscle and bone strength and metabolic markers in adults with chronic kidney disease (CKD), kidney failure or kidney transplants. However, the mechanisms that underlie these benefits have received little attention, and the available clinical evidence is mainly from small, short-duration (<12 weeks) exercise intervention studies. The available data, mainly from patients with CKD or on dialysis, suggest that exercise-mediated shifts towards a less inflammatory immune cell profile, enhanced activity of the NRF2 pathway and reduced monocyte infiltration into adipose tissue may underlie improvements in inflammatory biomarkers. Exercise-mediated increases in nitric oxide release and bioavailability, reduced angiotensin II accumulation in the heart, left ventricular remodelling and reductions in myocardial fibrosis may contribute to improvements in left ventricular hypertrophy. Exercise stimulates an anabolic response in skeletal muscle in CKD, but increases in mitochondrial mass and satellite cell activation seem to be impaired in this population. Exercise-mediated activation of the canonical wnt pathway may lead to bone formation and improvements in the levels of the bone-derived hormones klotho and fibroblast growth factor 23 (FGF23). Longer duration studies with larger sample sizes are needed to confirm these mechanisms in CKD, kidney failure and kidney transplant populations and provide evidence for targeted exercise interventions.

Training vs. Tolerance: The Yin/Yang of the Innate Immune System

For almost nearly a century, memory functions have been attributed only to acquired immune cells. Lately, this paradigm has been challenged by an increasing number of studies revealing that innate immune cells are capable of exhibiting memory-like features resulting in increased responsiveness to subsequent challenges, a process known as trained immunity (known also as innate memory). In contrast, the refractory state of endotoxin tolerance has been defined as an immunosuppressive state of myeloid cells portrayed by a significant reduction in the inflammatory capacity. Both training as well tolerance as adaptive features are reported to be accompanied by epigenetic and metabolic alterations occurring in cells. While training conveys proper protection against secondary infections, the induction of endotoxin tolerance promotes repairing mechanisms in the cells. Consequently, the inappropriate induction of these adaptive cues may trigger maladaptive effects, promoting an increased susceptibility to secondary infections-tolerance, or contribute to the progression of the inflammatory disorder-trained immunity. This review aims at the discussion of these opposing manners of innate immune and non-immune cells, describing the molecular, metabolic and epigenetic mechanisms involved and interpreting the clinical implications in various inflammatory pathologies.

Fatigue in Patients on Chronic Hemodialysis: The Role of Indoleamine 2,3-Dioxygenase (IDO) Activity, Interleukin-6, and Muscularity

Fatigue is a frequent symptom in hemodialysis (HD), and the indolamine-2,3-dioxygenase (IDO) metabolic trap has been hypothesized in the pathogenesis of fatigue. The association between IDO activity according to fatigue and its relationship with muscle mass and function in HD patients was verified. Chronic HD patients were considered, and fatigue was assessed. The plasma kynurenines and tryptophan ratio (Kyn/Trp), as surrogate of IDO activity, and interleukin (IL)-6 were measured. Muscularity was assessed by BIA and muscle strength by hand-grip dynamometer. 50 HD patients were enrolled, and fatigue was present in 24% of the cohort. Patients with fatigue showed higher Kyn/Trp (p = 0.005), were older (p = 0.007), and IL-6 levels resulted higher than in non-fatigue patients (p < 0.001). HD patients with fatigue showed lower intracellular water (surrogate of muscle mass) (p < 0.001), as well as lower hand grip strength (p = 0.02). The Kyn/Trp ratio positively correlated with IL-6 and ECW/ICW (p = 0.004 and p = 0.014). By logistic regression analysis, higher ICW/h² was associated with lower odds of fatigue (OR, 0.10; 95% CI, 0.01 to 0.73). In conclusion, our cohort fatigue was associated with a higher Kyn/Trp ratio, indicating a modulation of IDO activity. The Kyn/Trp ratio correlated with IL-6, suggesting a potential role of IDO and inflammation in inducing fatigue and changes in muscularity.

Trained immunity - basic concepts and contributions to immunopathology

Trained immunity is a functional state of the innate immune response and is characterized by long-term epigenetic reprogramming of innate immune cells. This concept originated in the field of infectious diseases - training of innate immune cells, such as monocytes, macrophages and/or natural killer cells, by infection or vaccination enhances immune responses against microbial pathogens after restimulation. Although initially reported in circulating monocytes and tissue macrophages (termed peripheral trained immunity), subsequent findings indicate that immune progenitor cells in the bone marrow can also be trained (that is, central trained immunity), which explains the long-term innate immunity-mediated protective effects of vaccination against heterologous infections. Although trained immunity is beneficial against infections, its inappropriate induction by endogenous stimuli can also lead to aberrant inflammation. For example, in systemic lupus erythematosus and systemic sclerosis, trained immunity might contribute to inflammatory activity, which promotes disease progression. In organ transplantation, trained immunity has been associated with acute rejection and suppression of trained immunity prolonged allograft survival. This novel concept provides a better understanding of the involvement of the innate immune response in different pathological conditions, and provides a new framework for the development of therapies and treatment strategies that target epigenetic and metabolic pathways of the innate immune system.

Effects of Standardized Brazilian Green Propolis Extract (EPP-AF®) on Inflammation in Haemodialysis Patients: A Clinical Trial

BACKGROUND

Patients on haemodialysis (HD) present a significant inflammatory status, which has a pronounced negative impact on their outcomes. Propolis is a natural resin with anti-inflammatory and immunomodulatory properties. We assessed the safety and impact of a standardized Brazilian green propolis extract (EPP-AF®) on the inflammatory status in patients under conventional HD.

METHODS

Patients were assigned to receive 200 mg/day of EPP-AF® for 4 weeks followed by 4 weeks without the drug, and changes in plasma levels of interleukins (ILs), interferon gamma (IFN-γ), tumour necrosis factor-alpha (TNF-α), and high-sensitivityc-reactive protein (HsCRP) were measured. A heatmap was used to illustrate trends in data variation.

RESULTS

In total, 37 patients were included in the final analysis. Patients presented an exacerbated inflammatory state at baseline. During EPP-AF® use, there was a significant reduction in IFN-γ (p=0.005), IL-13 (p=0.04 2), IL-17 (p=0.039), IL-1ra (p=0.008), IL-8 (p=0.009), and TNF-α (p  <  0.001) levels compared to baseline, and significant changes were found in Hs-CRP levels. The heatmap demonstrated a pattern of pronounced proinflammatory status at baseline, especially in patients with primary glomerulopathies, and a clear reduction in this pattern during the use of EPP-AF®. There was a tendency to maintain this reduction after suspension of EPP-AF®. No significant side effects were observed.

CONCLUSION

Patients under haemodialysis presented a pronounced inflammatory status, and EPP-AF® was demonstrated to be safe and associated with a significant and maintained reduction in proinflammatory cytokines in this population. This trial is registered with Clinicaltrials.gov NCT04072341.

Pro-inflammatory cytokines as potential predictors for intradialytic hypotension

Background

Intradialytic hypotension (IDH) is a common complication in maintaining hemodialysis (MHD) patients. Immune activation might be part of the mechanisms. However, the association between pro-inflammatory cytokines and blood pressure (BP) has not been deeply explored. So we aim to evaluate the potential role of pro-inflammatory cytokines in IDH.

Methods

MHD patients starting hemodialysis before January 2016 were enrolled in our retrospective study. Patients' characteristics, laboratory results, and intradialytic BP were collected. IDH was defined as nadir systolic BP ≤ 90 mmHg during hemodialysis. The definition of IDH group was that those who suffered from more than one hypotensive event during one month after the enrollment (10% of dialysis treatments). Spearman correlation analysis and logistic regression were employed to explore the relationship between pro-inflammatory cytokines and IDH.

Results

Among 390 patients, 72 were identified with IDH (18.5%). High levels of serum tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were observed in the IDH group (p < 0.001). Both TNF-α and IL-1β positively correlated with predialysis BP (p < 0.01). Receiver operating characteristic curve (ROC) analysis was used to evaluate the diagnostic accuracy of serum IL-1β and TNF-α for IDH. The area under the curve of IL-1β was 0.772 (95% CI: 0.708-0.836, p < 0.01), and that of TNF-α was 0.701 (95% CI: 0.620-0.781, p < 0.01). After adjusting for patients' characteristics, biochemical parameters, comorbid conditions, predialysis BP, and medications, elevated TNF-α and IL-1β were still risk factors for IDH.

Conclusion

Pro-inflammatory cytokines (TNF-α and IL-1β) could be potential predictors for IDH.

Involvement of chronic inflammation via monocyte chemoattractant protein-1 in uraemic cardiomyopathy: a human biopsy study

Aims

Patients undergoing dialysis, even those without coronary artery disease or valvular abnormalities, sometimes present with reduced heart function, which resembles dilated cardiomyopathy (DCM). This condition is known as uraemic cardiomyopathy (UCM). The mechanisms of UCM development are not fully understood. Previous studies demonstrated that the balance between placental growth factor (PlGF) and fms‐like tyrosine kinase‐1 (Flt‐1) is correlated with renal function, and PlGF/Flt‐1 signalling is involved in the development of cardiovascular diseases in patients with chronic kidney disease. This study was conducted to evaluate the pathogenesis of UCM and clarify the differences in the mechanisms of UCM and DCM by using human endomyocardial biopsy and blood samples.

Methods and results

The clinical and pathological features of 30 patients on dialysis with reduced cardiac function [left ventricular ejection fraction (LVEF) ≤50%] (UCM group; mean age: 58.5 ± 9.4 years and LVEF: 39.1 ± 7.2%), 196 DCM patients (DCM group; mean age: 62.7 ± 14.0 years and LVEF: 33.5 ± 8.8%) as controls with reduced cardiac function (LVEF ≤ 45%), and 21 patients as controls with normal cardiac function (control group; mean age: 56.2 ± 19.3 years and LVEF: 67.5 ± 6.7%) were analysed. The percentage of the interstitial fibrosis area in the UCM group was greater than that in the DCM group (P = 0.045). In UCM patients, the percentage of the interstitial fibrosis area was positively correlated with the duration of renal replacement therapy (P < 0.001). The number of infiltrated CD68‐positive macrophages in the myocardium and expression of monocyte chemoattractant protein‐1 (MCP‐1) in cardiomyocytes were significantly greater in the UCM group than in the other groups (P < 0.001, respectively). Furthermore, while the serum level of soluble form of Flt‐1, an endogenous inhibitor of PlGF, in the UCM group was lower compared with that in the DCM group (P < 0.001), the serum levels of PlGF and PlGF/soluble form of Flt‐1 ratio and plasma level of MCP‐1 in the UCM group were higher than those in the DCM group (P < 0.001, respectively).

Conclusions

These results suggest that activated PlGF/Flt‐1 signalling and subsequent macrophage‐mediated chronic non‐infectious inflammation via MCP‐1 in the myocardium are involved in the pathogenesis of UCM.

Associations of Small Fiber Neuropathy with Geriatric Nutritional Risk Index and Arterial Stiffness in Hemodialysis

BACKGROUND

Peripheral neuropathy is a common neurological complication in uremic patients, and quantitative sensory testing (QST) is effective for diagnosis of small fiber neuropathy. Malnutrition and arterial stiffness are prevalent in patients undergoing hemodialysis (HD). The associations of small fiber neuropathy with nutritional status and arterial stiffness remain uncertain in maintenance HD patients.

METHODS

A total of 152 HD patients were included. Geriatric nutritional risk index (GNRI), an indicator of nutritional status, was calculated by serum albumin and actual and ideal body weight. Arterial stiffness was defined as brachial-ankle pulse wave velocity (baPWV) > 1400 cm/s. Small fiber neuropathy was assessed by an abnormal QST threshold of cold and warm sensation in patients' hands or feet. Multivariate forward logistic regression analysis was performed to examine the associations among abnormal QST threshold, GNRI, and arterial stiffness.

RESULTS

baPWV and prevalence of abnormal QST threshold were significantly higher in diabetic patients. Multivariate logistic analyses revealed that older age (OR, 1.081; 95% CI, 1.026-1.139, p = 0.003) and male gender (OR, 4.450; 95% CI, 1.250-15.836, p = 0.021) were associated with abnormal warm threshold of hands. Furthermore, diabetes (OR, 3.966; 95% CI, 1.351-11.819, p = 0.012) and lower GNRI (per 1 unit increase, OR, 0.935, 95% CI, 0.887-0.985, p = 0.012) were associated with abnormal cold threshold of feet. Arterial stiffness (OR, 5.479, 95% CI, 1.132-22.870, p = 0.020) and higher calcium-phosphorus product (OR, 1.071, 95% CI, 1.013-1.132, p = 0.015) were associated with abnormal warm threshold of feet.

CONCLUSIONS

Lower GNRI and arterial stiffness were significantly associated with small fiber neuropathy in patients undergoing HD. Malnutrition risk and vascular factors might play important roles in small fiber neuropathy among patients undergoing HD.

Hemodialysis-related headache: Still a challenge in 2020? Effect of conventional versus online hemodiafiltration from a study in Casablanca, Morocco

Hemodialysis-related headache (HRH) is a well-known clinical event. It is considered as one of the most commonly reported neurological symptoms among hemodialysis patients. Its epidemiological, physiological, clinical, and therapeutic data remain scarce and are poorly studied. Our aim was to determine the frequency of HRH in the region of Casablanca, Morocco, to describe its clinical characteristics and to explore the hypothesis that renal replacement techniques, such as conventional versus online hemodiafiltration may have an association on clinical adverse effects like HRH. A descriptive, cross-sectional, and multicentric study was carried out among 100 chronic hemodialysis patients for at least 6 months. HRH was defined according to criteria published by the International Classification of Headache Disorder third edition beta version (ICHD3β) [1]. Two different HD-modalities (standard HD and OL-HDF) have been investigated in order to explore their impact on HRH. Headache was reported by 60% of the patients including 41.6% of hemodialysis-related headache. HRH had on average a duration of 7.4 hours, pulsatile among 38% of interviewed patients and of moderate intensity in 48% of cases. In total, 51.3% of patients undergoing conventional hemodialysis modality reported HRH compared to 12.5% undergoing online hemodiafiltration technique (OL-HDF) (P = .008). Hemodialysis-related headache remains a poorly studied clinical event despite its high prevalence. Its diagnosis, management, and especially its prevention remain a challenge for the neurologist and the nephrologist. Our results suggest that OL-HDF is a promising therapeutic and preventive tool to reduce the incidence of HRH.

Role of Immune Dysregulation in Increased Mortality Among a Specific Subset of COVID-19 Patients and Immune-Enhancement Strategies for Combatting Through Nutritional Supplements

Background: The COVID-19 pandemic has been causing varying severities of illness. Some are asymptomatic and some develop severe disease leading to mortality across ages. This contrast triggered us explore the causes, with the background that a vaccine for effective immunization or a drug to tackle COVID-19 is not too close to reality. We have discussed strategies to combat COVID-19 through immune enhancement, using simple measures including nutritional supplements. Discussion: A literature search on mortality-related comorbid conditions was performed. For those conditions, we analyzed the pro-inflammatory cytokines, which could cause the draining of the immune reservoir. We also analyzed the immune markers necessary for the defense mechanism/immune surveillance against COVID-19, especially through simple means including immune enhancing nutritional supplement consumption, and we suggest strategies to combat COVID-19. Major comorbid conditions associated with increased mortality include cardiovascular disease (CVD), diabetes, being immunocompromised by cancer, and severe kidney disease with a senile immune system. Consumption of Aureobasidium pullulans strain (AFO-202) beta 1,3-1,6 glucan supported enhanced IL-8, sFAS macrophage activity, and NK cells' cytotoxicity, which are major defense mechanisms against viral infection. Conclusion: People with co-morbid conditions who are more prone to COVID-19-related deaths due to immune dysregulation are likely to benefit from consuming nutritional supplements that enhance the immune system. We recommend clinical studies to validate AFO-202 beta glucan in COVID-19 patients to prove its efficacy in overcoming a hyper-inflammation status, thus reducing the mortality, until a definite vaccine is made available.

Intradialytic hypotension prevalence, influencing factors, and nursing interventions: prospective results of 744 hemodialysis sessions

INTRODUCTION

The aim of this study was to evaluate intradialytic hypotension (IDH) prevalence, influencing factors, and nursing interventions in hemodialysis (HD) patients.

METHODS

This descriptive and cross-sectional study was conducted at a private dialysis center. The patients were followed-up in terms of IDH development based on the European Best Practice Guidelines criteria during six consecutive HD sessions. The study followed the STROBE checklist.

RESULTS

A total of 744 hemodialysis sessions of 124 patients were monitored. IDH developed in 51.6% of the patients and the prevalence was 17.60%. The most common nursing interventions were stopping ultrafiltration and isotonic saline solution administration. White blood cell (WBC) (p = 0.017) and creatinine (p = 0.005) values were statistically significantly higher in patients developing IDH. WBC was found to increase IDH development risk 0.796 times (95% CI [0.657-0.996], p = 0.021).

CONCLUSION

Nursing staff awareness regarding the frequency of IDH in hemodialysis patients and the related symptoms needs to be increased.

Intestinal microbiota alterations in chronic kidney disease and the influence of dietary components

In chronic kidney disease, as in many other diseases, dysbiosis of intestinal microbiota has been reported as a disturbance or imbalance of the normal microbiome content that could disrupt the symbiotic relationship between the host and associated microbes, a disruption that can result in diseases. The disruption of gut barrier function allows the translocation of endotoxins and bacterial metabolites to the organism, thus contributing to uremic toxicity, inflammation and progression of chronic kidney disease. Increased intake of some nutrients and different nutritional strategies have been proposed to modulate gut microbiota, thus offering the opportunity for therapeutic interventions modifying the diet, decreasing uremic toxins production, increasing toxin excretion and finally modifying the normal microbiome content. The use of probiotics, prebiotics and low protein diets, among other approaches, could also improve this imbalance and/or decrease permeability of the intestinal barrier. In this review, the link between nutrients, microbiota and uremic toxins with chronic kidney disease progression has been studied thoroughly. Furthermore, this review outlines potential mechanisms of action and efficacy of probiotics, prebiotics and low protein diets as a new chronic kidney disease management tool.

Hemodialysis Does Not Induce Detectable Activation of the Contact System of Coagulation

Introduction

Systemic anticoagulation is administered during hemodialysis to prevent clotting of the extracorporeal circuit. The role of contact system activation in thrombin generation during hemodialysis using current era dialyzer membranes is unknown.

Methods

We performed a single-center randomized crossover study. Ten patients treated with hemodialysis underwent 3 standardized hemodialysis sessions. For every patient, each session was performed with a different type of dialyzer membrane (polyphenylene [PP], polymethylmetacrylate [PMMA], polyethylenimine-coated polyacrylonitrile [AN69ST]). Blood samples were collected before and 5, 15, 30, 90, and 240 minutes after blood pump start to evaluate coagulation activation (thrombin–antithrombin complex [TAT], prothrombin fragment 1+2 [PF1+2], activated factor XII [FXIIa], kallikrein, activated factor XI [FXIa]). Plasma of healthy volunteers (n = 20) was used as a reference.

Results

Baseline TAT and PF1+2 levels were higher in hemodialysis patients compared to healthy controls (median [interquartile range] for TAT: 3.3 [2.9–4.2] vs. 2.4 [2.3–2.5] μg/l [P = 0.0002] and for PF1+2: 647 [478–737] vs. 138 [125–254] pmol/l [P < 0.0002]). Despite the use of systemic anticoagulation, TAT further increased during treatment, with the increase starting after 30 minutes (median TAT at t240: 9.0 μg/l (PP), 5.5 μg/l (PMMA), and 7.2 μg/l (AN69ST), all P < 0.05 vs. baseline). Contact system markers FXIIa and kallikrein did not differ significantly between dialysis patients and healthy controls, whereas baseline FXIa levels were significantly lower in dialysis patients compared to healthy controls (P = 0.001). Levels of all contact system markers remained unchanged during hemodialysis with all types of dialyzer membranes.

Conclusion

Routine hemodialysis using systemic heparin anticoagulation induces coagulation activation without measurable contact system activation.

Genetic Polymorphisms within Interferon-λ Region and Interferon-λ3 in the Human Pathophysiology: Their Contribution to Outcome, Treatment, and Prevention of Infections with Hepatotropic Viruses

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Genetic polymorphisms within the interferon λ (IFN-λ) chromosomal region, mainly rs12979860 of IFN-λ4 gene (IFNL4), are known as associated with spontaneous hepatitis C virus (HCV) resolution and sustained viral response to therapy with pegylated interferon- α and ribavirin. Strong linkage disequilibrium of IFNL4 rs12979860 with IFNL4 rs368234815, which is casually associated with HCV spontaneous and therapeutical eradication, at least partially explains favorable HCV outcomes attributed to major homozygosity in rs12979860. Effects of IFN-based antiviral treatment are associated with pretreatment expression of the IFN-λ1 receptor, expression of hepatic IFN-stimulated genes, production of IFN- λ4, and preactivation of the JAK-STAT signaling. Nowadays direct-acting antivirals (DAAs) became a potent tool in the treatment of hepatitis C, but IFN-λs are still under investigation as potential antivirals and might be an option in HCV infection (DAA resistance, recurrent viremia, adverse effects).

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Patients with altered immunocompetence are especially prone to infections. In uremic subjects, polymorphisms within the IFN-λ chromosomal region associate with spontaneous HCV clearance, similarly like in the non-uremic population. Circulating IFN-λ3 shows a positive correlation with plasma titers of antibodies to surface antigen of hepatitis B virus (anti-HBs), which are crucial for protection against hepatitis B virus. More efficient anti-HBs production in the presence of higher IFN-λ3 levels might occur due to IFN-λ3-induced regulation of indoleamine 2,3-dioxygenase (IDO) expression. IFN-stimulated response element is a part of IDO gene promoter. It is worth further investigation whether IDO gene, circulating IDO, genetic polymorphisms within the IFN-λ region, and circulating IFN-λ3 act in concordance in immunological response to hepatotropic viruses.

Biocompatibility of Polysulfone Hemodialysis Membranes and Its Mechanisms: Involvement of Fibrinogen and Its Integrin Receptors in Activation of Platelets and Neutrophils

Activation of blood cells during hemodialysis is considered to be a significant determinant of biocompatibility of the hemodialysis membrane because it may affect patient health adversely through microvascular inflammation and oxidative stress. This study found very different cell activation among various polysulfone (PSf) hemodialysis membranes. For example, CX-U, a conventional PSf membrane, induced marked adhesion of platelets to its surface and increased surface expression of activated CD11b and production of reactive oxygen species (ROS) by neutrophils; while NV-U, a hydrophilic polymer-immobilized PSf membrane, caused little platelet adhesion and slight CD11b expression and ROS production by neutrophils. Analysis of the molecular mechanisms of the above phenomena on CX-U and NV-U indicated that anti-integrin GPIIb/IIIa antibody blocked platelet adhesion, and that the combination of anti-CD11b (integrin α subunit of Mac-1) and anti-integrin αvβ3 antibodies blocked ROS production by neutrophils. Plasma-derived fibrinogen, a major ligand of GPIIb/IIIa, Mac-1, and αvβ3 on membranes, was thus analyzed and found to be more adsorbed to CX-U than to NV-U. Moreover, comparison between five PSf membranes showed that the number of adherent platelets and neutrophil ROS production increased with increasing fibrinogen adsorption. These results suggested that fibrinogen, adsorbed on membranes, induced GPIIb/IIIa-mediated platelet activation and Mac-1/αvβ3-mediated neutrophil activation, depending on the amount of adsorption. In conclusion, the use of biocompatible membranes like NV-U, which show lower adsorption of fibrinogen, is expected to reduce hemodialysis-induced inflammation and oxidative stress by minimizing cell activation.

Association of brain-derived neurotrophic factor and interleukin-6 serum levels with depressive and anxiety symptoms in hemodialysis patients

OBJECTIVE

This study assessed the possible association of serum brain-derived neurotrophic factor (BDNF) and interleukin-6 (IL-6) with depressive and anxiety symptoms in hemodialysis (HD) patients.

METHOD

An analytical cross-sectional study was conducted over 274 HD patients from March to October 2017. The Hospital Anxiety and Depression Scale (HADS) was utilized to evaluate depressive (HADS-D) and anxiety (HADS-A) symptoms. The HADS-D/A is a self-report instrument that has a maximum score of 21. Serum BDNF and IL-6 were measured using enzyme-linked immunosorbant assay (ELISA).

RESULTS

Serum IL-6 was significantly higher in patients with depressive symptoms compared to normal (20.47 ± 4.27 pg/mL for HADS-D ≥11 versus 9.26 ± 1.59 pg/mL for HADS-D <7, p = 0.014). Multivariable regression analysis revealed that IL-6, education level, hypertension, and dialysis duration were significant predictors of HADS-D. Also, gender, education level, hypertension, and the number of dialysis sessions/week were significant predictors of HADS-A. Significant positive correlation was shown between HADS-D and IL-6 (r = 0.1729, p = 0.004).

CONCLUSION

Collectively, HD patients with depressive symptoms showed higher levels of IL-6, supporting previous findings that the circulating inflammatory mediator IL-6 can be used as a biomarker for prediction of depressive symptoms in HD patients. Further longitudinal or interventional studies are needed to further validate this association.

Physiological and psychosocial stressors among hemodialysis patients in the Buea Regional Hospital, Cameroon

INTRODUCTION

End Stage Renal Disease (ESRD) is an irreversible kidney condition and hemodialysis is the most frequent treatment option used for this condition. However, hemodialysis also has a detrimental impact on the quality of life and the individuals' physical and psychosocial wellbeing. The main objective of this study was to identify physiological and psychosocial stressors faced by patients undergoing hemodialysis in the Buea Regional Hospital in Cameroon.

METHODS

A cross-sectional study was carried out (December 2016 - January 2017) among patients undergoing hemodialysis at the Buea regional hospital. Data were collected with the use of a structured questionnaire and analyzed using SPSS version 21.0. Quantitative variables were expressed as frequencies, percentages and means.

RESULTS

Among the patients undergoing hemodialysis, 28 (70.0%) were below 5-year dialysis while 12 (30.0%) had been on dialysis for five years and more. 21(52.5%) were male and 19(47.5%) female. Half of the patients were married 20(50%), 13(32.5%) were single, 6(15%) were divorced, and one (2.5%) was a widower. Also, 28 (70.0%) were below 5-year dialysis while 12 (30.0%) had been on dialysis for five years and more. All participants experienced at least one or more physiological and psychosocial stressors. Among physiological stressors, the most frequent were feeling tired (97%), followed by arterial and venous stick (88%) while itching (49.5%) was the least noted physiological stressor. Among psycho-social stressors, the most recurrent were transportation to and from the hospital (99.5%), cost of treatment (99.5%) and Limits on time and place of vacation (99%), followed by Limitation in physical activities, frequent hospitalizations, the length of time on dialysis, uncertainty about the future, changes in life style, increased dependence and sleep disturbances.

CONCLUSION

The topic of stressors is of importance among patients receiving dialysis, as these affect their psycho-social and physiological wellbeing. Thus, nephrologists, nurses and family members play an important role in providing patients with effective psycho-social and physiological support.

Humoral immunity to memory antigens and pathogens is maintained in patients with chronic kidney disease

Patients with chronic kidney disease (CKD) have an increased risk of infection and poorer responses to vaccination. This suggests that CKD patients have an impaired responsiveness to all antigens, even those first encountered before CKD onset. To examine this we evaluated antibody responses against two childhood vaccine antigens, tetanus (TT) and diphtheria toxoids (DT) and two common pathogens, cytomegalovirus (CMV) and Salmonella enterica serovar Enteritidis (SEn) in two independent cohorts consisting of age-matched individuals with and without CKD. Sera were evaluated for antigen-specific IgG titres and the functionality of antibody to SEn was assessed in a serum bactericidal assay. Surprisingly, patients with CKD and control subjects had comparable levels of IgG against TT and DT, suggesting preserved humoral memory responses to antigens encountered early in life. Lipopolysaccharide-specific IgG titres and serum bactericidal activity in patients with CKD were also not inferior to controls. CMV-specific IgG titres in seropositive CKD patients were similar or even increased compared to controls. Therefore, whilst responses to new vaccines in CKD are typically lower than expected, antibody responses to antigens commonly encountered prior to CKD onset are not. The immunodeficiency of CKD is likely characterised by failure to respond to new antigenic challenges and efforts to improve patient outcomes should be focussed here.

Examining hemodialyzer membrane performance using proteomic technologies

The success and the quality of hemodialysis therapy are mainly related to both clearance and biocompatibility properties of the artificial membrane packed in the hemodialyzer. Performance of a membrane is strongly influenced by its interaction with the plasma protein repertoire during the extracorporeal procedure. Recognition that a number of medium-high molecular weight solutes, including proteins and protein-bound molecules, are potentially toxic has prompted the development of more permeable membranes. Such membrane engineering, however, may cause loss of vital proteins, with membrane removal being nonspecific. In addition, plasma proteins can be adsorbed onto the membrane surface upon blood contact during dialysis. Adsorption can contribute to the removal of toxic compounds and governs the biocompatibility of a membrane, since surface-adsorbed proteins may trigger a variety of biologic blood pathways with pathophysiologic consequences. Over the last years, use of proteomic approaches has allowed polypeptide spectrum involved in the process of hemodialysis, a key issue previously hampered by lack of suitable technology, to be assessed in an unbiased manner and in its full complexity. Proteomics has been successfully applied to identify and quantify proteins in complex mixtures such as dialysis outflow fluid and fluid desorbed from dialysis membrane containing adsorbed proteins. The identified proteins can also be characterized by their involvement in metabolic and signaling pathways, molecular networks, and biologic processes through application of bioinformatics tools. Proteomics may thus provide an actual functional definition as to the effect of a membrane material on plasma proteins during hemodialysis. Here, we review the results of proteomic studies on the performance of hemodialysis membranes, as evaluated in terms of solute removal efficiency and blood-membrane interactions. The evidence collected indicates that the information provided by proteomic investigations yields improved molecular and functional knowledge and may lead to the development of more efficient membranes for the potential benefit of the patient.

Circulating Interferon-λ3, Responsiveness to HBV Vaccination, and HBV/HCV Infections in Haemodialysis Patients

The IFN-λ3 gene (IFNL3) plays a role in HCV clearance. We investigated circulating IFN-λ3 and IFNL3 SNPs in haemodialysis patients who differed in their response to HBV vaccination and their HBV/HCV infection status. In 201 patients, plasma IFN-λ3 was determined using ELISA. IFNL3 SNPs (rs12979860, rs8099917) were genotyped using HRM analysis. Differences in IFN-λ3 levels were shown between responders and nonresponders to HBV vaccination and between HBsAg-positive patients and those who developed anti-HBs after infection and became HBsAg negative. HBV vaccine responders without HCV resolution revealed lower IFN-λ3 than noninfected responders. HBsAg/HCV RNA-positive subjects showed lower IFN-λ3 than patients positive only for HCV RNA or subjects who resolved both infections. Circulating IFN-λ3 correlated positively with anti-HBs and negatively with positive HCV RNA testing in the adjusted regression analyses. HBV vaccine nonresponders, HBsAg-positive patients, and subjects with replicating HCV composed a group with unfavourable outcomes. Responders to HBV vaccination, subjects who became HBsAg negative, and those who cleared HCV were analysed as having favourable outcomes. The latter showed higher IFN-λ3 but did not differ in distribution of IFNL3 SNPs compared with subjects with unfavourable outcomes. Higher IFN-λ3 concentrations are associated with response to HBV vaccination, self-limited HBV infection, and HCV resolution.

The prognostic value of the furosemide stress test in predicting delayed graft function following deceased donor kidney transplantation

OBJECTIVES AND METHODS

The Furosemide Stress Test (FST) is a novel dynamic assessment of tubular function that has been shown in preliminary studies to predict patients who will progress to advanced stage acute kidney injury, including those who receive renal replacement therapy (RRT). The aim of this study is to investigate if the urinary response to a single intraoperative dose of intravenous furosemide predicts delayed graft function (DGF) in patients undergoing deceased donor kidney transplant.

RESULTS

On an adjusted multiple logistic regression, a single 100 mg dose of intraoperative furosemide after the anastomosis of the renal vessels (FST) predicted the need for RRT at 2 and 6 h post kidney transplantation (KT). Recipient urinary output was measured at 2 and 6 h post furosemide administration. In receiver-operating characteristic (ROC) analysis, the FST predicted DGF with an area-under-the curve of 0.85 at an optimal urinary output cut-off of <600 mls at 6 h with a sensitivity of and a specificity of 83% and 74%, respectively.

CONCLUSIONS

The FST is a predictor of DGF post kidney transplant and has the potential to identify patients requiring RRT early after KT.

C reactive protein and depressive symptoms in hemodialysis patients: A questionable association

INTRODUCTION

Patients with advanced chronic kidney disease (CKD) on haemodialysis (HD) may have increased C reactive protein (CRP) values and depressive symptoms. There is debate about the strength and nature of previously reported associations. We investigated these issues in a cohort of patients on HD.

METHODS

We screened for depressive symptoms using two valadiated depression screening tools: the Beck Depression Inventory-II (BDI-II), Patient Health Questionnaire (PHQ-9). Demographic and clinical correlates of depression symptoms were eveluated in adjusted linear and logistic regression models, which included extra renal comorbidity and high CRP (>5 mg/L).

FINDINGS

Three hundred and ninety-six HD patients were studied; 63.1% male, mean age 63.1 ± 16.4 years, median CRP 6 (5-15) mg/L. Depression scores were similar in those with normal and high CRP (BDI-II (9(5-17) vs. 11(6-20)) or PHQ (4(2-9) vs. 6(2-10)). In adjusted multivariable regression BDI-II scores were associated with previous history of depression (β 10.8, P < 0.001), serum albumin (β 0.41, P < 0.001), anuria (β 2.4, P < 0.037), diabetes (β 2.7, P = 0.033), and age (β -0.10, P = 0.009). High CRP was not independently associated with BDI-II (β 2.20, P = 0.057), though was with PHQ-9 (β 1.20, P = 0.046). In logistic regression those with high CRP were 1.9 times more likely to score ≥16 on BDI-II screening (P = 0.016), but did not relate significantly to a PHQ-score ≥10.

DISCUSSION

A relationship was observed between CRP and depression symptoms, though the effect was small, of unlikely clinical significance, and inconsistent between depression measures. Previous reports of this association may reflect overlap between symptoms of depression and advanced CKD.

Antibodies to HBV surface antigen in relation to interferon-λ3 in hemodialysis patients

AIM

To investigate circulating IFN-λ3 and IFNL3 polymorphisms in hemodialysis (HD) patients differing in HBV surface antigen antibody (anti-HBs) production.

METHODS

The study included 106 HBV-vaccinated HD patients (88 developed anti-HBs) and 36 HBV-infected HD subjects (27 developed anti-HBs). Plasma IFN-λ3 (enzyme-linked immunosorbent assay) and rs12979860 (C>T) and rs8099917 (T>G) in IFNL3 (high-resolution melting curve analysis) were analyzed with regard to the association with anti-HBs production in response to HBV vaccination or infection. The results were adjusted for gender, age, cause of renal disease, dialysis vintage, dialysis modality, IFN-λ3, and 25(OH)D as appropriate.

RESULTS

HBV vaccine responders had higher circulating IFN-λ3 (ng/L) than non-responders (120, 36-233 vs. 53, 33-109, P<0.000001). Patients who generated anti-HBs after HBV infection also had higher circulating IFN-λ3 levels than those who did not (133, 35-215 vs. 71, 9-229, P=0.043). The IFN-λ3 concentration correlated with the anti-HBs titer in vaccinated (r=0.614, P<0.000001) and infected patients (r=0.589, P=0.0002). Plasma IFN-λ3 was the only significant indicator of responsiveness to HBV vaccination (adjusted P=0.018) and remained the only significant associate for the development of post-infection anti-HBs (adjusted P=0.049). A plasmaIFN-λ3 level of 85.5ng/L was thecut-off value for theprognosis of an anti-HBs titer below vs. equal to or over 10IU/L in the entire group of HD patients (ROC sensitivity 68.7%, specificity 85.2%, and AUC 0.827). Significant associations were not found between IFN-λ3 and IFNL3 rs12979860. Subjects treated with low flux HD that harbored the TT genotype in rs8099917 showed higher IFN-λ3 levels than patients bearing the G allele in rs8099917 (139, 68-233 vs. 103, 9-208, P=0.049).

CONCLUSION

In HD patients, circulating IFN-λ3 strongly correlates with anti-HBs production after HBV vaccination and infection. IFNL3 rs8099917 polymorphisms seem to be associated with IFN-λ3 plasma levels in HD subjects.

Advances in Understanding and Management of Residual Renal Function in Patients with Chronic Kidney Disease

BACKGROUND

Residual renal function (RRF), defined as the ability of native kidneys to eliminate water and uremic toxins, is closely correlated with mortality and morbidity rates among patients receiving either peritoneal dialysis (PD) or hemodialysis (HD) via continuous clearance of middle-sized molecules and protein-bound solutes. Therefore, preserving RRF is considered to be one of the primary goals in managing patients with end-stage renal disease (ESRD).

SUMMARY AND KEY MESSAGES

In this article, we provide a review on the understanding and management of RRF in patients on dialysis. RRF may be estimated and measured by calculating the mean 24-hour urine creatinine level and urea clearance. Currently, several middle-sized molecules are reported but rarely used in practice. Many risk factors such as original renal diseases, dietary intake, and nephrotoxic agents impair RRF. Targeting such factors may halt the decline in RRF and offer better outcomes for patients on PD or HD. Except for in PD patients, RRF is a powerful predictor of survival in HD patients. RRF requires more clinical and research attention in the care of patients with ESRD on dialysis.

Evaluation of Intermittent Hemodialysis in Critically Ill Cancer Patients with Acute Kidney Injury Using Single-Pass Batch Equipment

BACKGROUND

Data on renal replacement therapy (RRT) in cancer patients with acute kidney injury (AKI) in the intensive care unit (ICU) is scarce. The aim of this study was to assess the safety and the adequacy of intermittent hemodialysis (IHD) in critically ill cancer patients with AKI.

METHODS AND FINDINGS

In this observational prospective cohort study, 149 ICU cancer patients with AKI were treated with 448 single-pass batch IHD procedures and evaluated from June 2010 to June 2012. Primary outcomes were IHD complications (hypotension and clotting) and adequacy. A multiple logistic regression was performed in order to identify factors associated with IHD complications (hypotension and clotting). Patients were 62.2 ± 14.3 years old, 86.6% had a solid cancer, sepsis was the main AKI cause (51%) and in-hospital mortality was 59.7%. RRT session time was 240 (180-300) min, blood/dialysate flow was 250 (200-300) mL/min and UF was 1000 (0-2000) ml. Hypotension occurred in 25% of the sessions. Independent risk factors (RF) for hypotension were dialysate conductivity (each ms/cm, OR 0.81, CI 0.69-0.95), initial mean arterial pressure (each 10 mmHg, OR 0.49, CI 0.40-0.61) and SOFA score (OR 1.16, CI 1.03-1.30). Clotting and malfunctioning catheters (MC) occurred in 23.8% and 29.2% of the procedures, respectively. Independent RF for clotting were heparin use (OR 0.57, CI 0.33-0.99), MC (OR 3.59, CI 2.24-5.77) and RRT system pressure increase over 25% (OR 2.15, CI 1.61-4.17). Post RRT blood tests were urea 71 (49-104) mg/dL, creatinine 2.71 (2.10-3.8) mg/dL, bicarbonate 24.1 (22.5-25.5) mEq/L and K 3.8 (3.5-4.1) mEq/L.

CONCLUSION

IHD for critically ill patients with cancer and AKI offered acceptable hemodynamic stability and provided adequate metabolic control.

Aging and low-grade inflammation reduce renal function in middle-aged and older adults in Japan and the USA

The objective of this study was to investigate the effects of low-grade inflammation on age-related changes in glomerular filtration rate (GFR) in middle-aged and older white Americans, African-Americans, and Japanese adults. Serum creatinine, C-reactive protein (CRP), and interleukin-6 (IL-6) levels were determined for 1570 adult participants in two surveys of aging in the USA and Japan (N = 1188 and 382, respectively). Kidney function declined with age in both countries and was associated with IL-6 and CRP. IL-6 and CRP also influenced the extent of the arithmetic bias when calculating the GFR using the chronic kidney disease epidemiology (CKD-EPI) formula with just serum creatinine. Younger African-Americans initially had the highest GFR but showed a steep age-related decrement that was associated with elevated inflammation. Japanese adults had the lowest average GFR but evinced a large effect of increased inflammatory activity when over 70 years of age. Importantly, our results also indicate that low-grade inflammation is important to consider when evaluating kidney function solely from serum creatinine.

A review of the neuro- and systemic inflammatory responses in post concussion symptoms: Introduction of the "post-inflammatory brain syndrome" PIBS

Post-concussion syndrome is an aggregate of symptoms that commonly present together after head injury. These symptoms, depending on definition, include headaches, dizziness, neuropsychiatric symptoms, and cognitive impairment. However, these symptoms are common, occurring frequently in non-head injured controls, leading some to question the existence of post-concussion syndrome as a unique syndrome. Therefore, some have attempted to explain post-concussion symptoms as post-traumatic stress disorder, as they share many similar symptoms and post-traumatic stress disorder does not require head injury. This explanation falls short as patients with post-concussion syndrome do not necessarily experience many key symptoms of post-traumatic stress disorder. Therefore, other explanations must be sought to explain the prevalence of post-concussion like symptoms in non-head injury patients. Many of the situations in which post-concussion syndrome like symptoms may be experienced such as infection and post-surgery are associated with systemic inflammatory responses, and even neuroinflammation. Post-concussion syndrome itself has a significant neuroinflammatory component. In this review we examine the evidence of neuroinflammation in post-concussion syndrome and the potential role systemic inflammation plays in post-concussion syndrome like symptoms. We conclude that given the overlap between these conditions and the role of inflammation in their etiologies, a new term, post-inflammatory brain syndromes (PIBS), is necessary to describe the common outcomes of many different inflammatory insults. The concept of post-concussion syndrome is in its evolution therefore, the new term post-inflammatory brain syndromes provides a better understanding of etiology of its wide-array of symptoms and the wide array of conditions they can be seen in.

Association of initial twice-weekly hemodialysis treatment with preservation of residual kidney function in ESRD patients

BACKGROUND

Residual kidney function (RKF) has consistently been a predictor of greater survival in maintenance hemodialysis (MHD) patients. The relationship between hemodialysis (HD) treatment frequency and RKF preservation has not been well examined. We hypothesized that initial twice-weekly HD helps in maintaining a longer RKF.

METHODS

In a dialysis center in Shanghai, 168 ESRD patients were screened and finally 85 patients were identified for this main cohort study. We first examined these 85 MHD patients; 30 of them were initiated with twice-weekly HD for 6 months or longer and 55 patients were started and maintained on thrice-weekly HD treatment. Then a subcohort study in 48 incident MHD patients was implemented to assess the independent risk factors responsible for RKF decline during the first year of HD therapy. Multivariate logistic regression analysis was then employed to examine the odds ratio of RKF loss.

RESULTS

The main cohort study showed that the clinical outcomes were almost the same between the two groups in 85 patients, but the percent of patients with RKF loss was significantly lower in the twice-weekly group compared with the thrice-weekly group, especially during the first year of HD initiation. In the 48 incident MHD patients, we found no significant differences between the two groups except for variations in the HD frequency, weekly Kt/V. The multivariate analysis showed that factors such as the male gender, HD frequency, URR and intradialytic hypotension episode were associated with RKF loss, and the odds ratio of RKF loss for each additional HD treatment per week was 7.2.

CONCLUSION

Twice-weekly HD during the first year of dialysis therapy appears to be associated with better RKF preservation.

Determination of oxidative stress and cellular inflammation in patients with diabetic nephropathy and non-diabetic nephropathy being administered hemodialysis treatment due to chronic renal failure

OBJECTIVES

We aimed to evaluate oxidative stress [8-hydroxydeoxyguanosine (8-OHdG), malondialdehyde (MDA)] endothelial damage [asymmetric dimethylarginine (ADMA)] and markers of cellular inflammation [interleukin 6 (IL-6), tumor necrosis factor-alpha (TNF-α), neopterin (NP) and high-sensitivity C-reactive protein (hsCRP)] in patients with diabetic nephropathy (DN) and non-diabetic nephropathy who were being administered hemodialysis treatment because of chronic renal failure.

METHODS

In determining 8-OHdG, IL-6 and TNF-α levels, Enzyme-Linked Immuno-Sorbent Assay method was used. Serum MDA, ADMA and NP levels were determined by using high performance liquid chromatography (HPLC). And hs-CRP values were measured with nephelometric method.

RESULTS

Serum 8-OHdG and MDA levels were found statistically to have increased when compared with those of the control group in patients groups after dialysis. However, serum ADMA and neopterin levels were observed statistically to have decreased when compared with those of the control group in patients groups after dialysis. But, decreases on ADMA and neopterin levels are still much higher than those of control. IL-6 and TNF-α levels were found to have increased when compared with those of control group in patients groups before dialysis.

CONCLUSION

The oxidative stress in patients with DN, who were being treated with hemodialysis due to chronic renal failure, was higher than that of non-DN patients who were being treated with hemodialysis. In contrast with this, inflammation occurring in non-DN patients was found to have been higher than that of in patients with DN.

Prevalence and correlates of insomnia and obstructive sleep apnea in chronic kidney disease

Background:

Poor sleep quality, insomnia, and restless legs syndrome (RLS) and sleep apnea are common in patients with chronic kidney disease (CKD). Clinical correlates of these problems are poorly understood.

Aims:

This study was to find out the prevalence and correlates of insomnia and subjects with ‘high risk for obstructive sleep apnea (OSA)’ in adults with chronic kidney disease.

Materials and Methods:

One hundred and four adults with CKD were included. Their demographic data, details regarding kidney disease and hemodialysis (HD) were recorded. Presence of insomnia and its severity was assessed. They were screened for sleep apnea using a validated questionnaire.

Results:

Average age was 54.17 (± 12.96) years. 89.4% had stage 5 nephropathy and 78.8% subjects were on regular HD. Males outnumbered females. Insomnia was reported by 35.5%. Among these, 50% had chronic insomnia. Insomnia subjects had higher prevalence of diabetes (P = 0.01) and depression (P < 0.001). Fifty-one percent subjects were at “high risk for sleep apnea”. They had higher prevalence of diabetes (P < 0.001), coronary disease (P = 0.02), insomnia (P = 0.008), and experienced daytime symptoms of insomnia (P < 0.001). However, in the logistic regression, only male gender (odds ratio, OR = 13.59) and daytime symptoms of insomnia (OR = 7.34) were found to be associated with “higher risk for sleep apnea”.

Conclusion:

Insomnia was prevalent in CKD. Nearly half of these patients are at high risk for sleep apnea and a third of them suffer from insomnia. Hence, these patients should be screened for sleep disorders.

Depression, 5HTTLPR and BDNF Val66Met polymorphisms, and plasma BDNF levels in hemodialysis patients with chronic renal failure

OBJECTIVE

Depression is the most prevalent comorbid psychiatric disease among hemodialysis patients with end-stage renal disease. This cross-sectional study investigated whether depression in hemodialysis patients is associated with the polymorphism of the 5' flanking transcriptional region (5-HTTLPR) of the serotonin transporter gene, the valine (Val)-to-methionine (Met) substitution at codon 66 (Val66Met) polymorphism of the brain-derived neurotrophic factor (BDNF) gene, or plasma BDNF levels.

METHODS

A total of 188 participants (mean age: 58.5±14.0 years; 89 men and 99 women) receiving hemodialysis at the Chang Gung Memorial Hospital were recruited. The diagnosis of major depressive disorder (MDD) was confirmed using the Chinese version of the Mini International Neuropsychiatric Interview. The genotypes of 5-HTTLPR and BDNF Val66Met were conducted using polymerase chain reactions plus restriction fragment length polymorphism analysis. The plasma BDNF levels were measured using an enzyme-linked immunosorbent assay kit.

RESULTS

Forty-five (23.9%) patients fulfilled the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV-TR) criteria for a MDD. There were no significant effects of the 5-HTTLPR or BDNF Val66Met gene polymorphism on MDD among the hemodialysis patients. The plasma BDNF levels correlated significantly with age (P=0.003) and sex (P=0.047) but not with depression, the genotypes of 5-HTTLPR and BDNF Val66Met, the current antidepressant treatment, or the duration under hemodialysis.

CONCLUSION

Our results did not support the hypothesis of an involvement of the 5HTTLPR and BDNF Val66Met genotypes, or plasma BDNF levels in the pathogenesis of depression, in patients receiving hemodialysis. A study with a large sample size and homogenous patient group is warranted to confirm these findings.

Dialysis-related transcriptomic profiling: the pivotal role of heparanase

Peritoneal (PD) and hemodialysis (HD) represent the leading renal replacement therapies in advanced chronic kidney disease (CKD). Although absolutely necessary to ensure patient survival, these treatments are responsible for considerable biological alterations primarily due to the un-physiological contact of blood and tissues with bioincompatible devices or plastificants. Although extensively described, this complex dialysis-related deregulated bio-molecular machinery is still not completely known. Therefore, to select a set of genes deregulated in patients on dialysis treatment and to assess the possible differences between dialysis modalities, we measured the expression level of 132 genes involved in proteoglycans (PGs) biosynthesis/metabolism by microarray in peripheral blood mononuclear cells (PBMCs), biological elements involved in the inflammatory/immune response, from 5 healthy subjects (HS), 9 CKD, 10 PD, and 17 HD patients. We focused on PGs biosynthesis/metabolism pathways because of their involvement in the onset and development of several CKD-related clinical complications. Statistical analysis/bioinformatics identified 70 genes discriminating HD/PD patients from HS/CKD subjects (P < 0.009, FDR < 5%). Twenty-five genes were up-regulated (e.g. HPSE, VCAN, and VEGFA) and 45 down-regulated (e.g. IDS and HEXA) in PD/HD compared to HS/CKD. Gene expression and plasma activity of Heparanase (HPSE), one of the top selected up-regulated genes in PD/HD, validated microarray results. In addition, for the second part of the study, HPSE plasmatic activities were first assessed in an independent testing-group (7 HS, 10 CKD, 17 PD, and 11 HD), and then correlated with high-sensitive C reactive protein (HS-CRP) measurements. HPSE activity was higher in PD and HD versus CKD/HS and it correlated with HS-CRP levels (R (2 )= 0.37, P = 0.007). Lipopolysaccharide (LPS)-stimulated PBMCs showed a significant up-regulation of HPSE mRNA level (P = 0.04). Our results revealed that dialysis treatments induce change in the transcriptomic pattern of biosynthetic proteoglycans in PBMCs with an up-regulation of HPSE. Our selected genes could be useful in the future as potential biomarkers and new therapeutic targets.

Phenotypic features of innate and adaptive immunity in patients with chronic hepatitis C and end-stage renal disease

BACKGROUND

The knowledge of the immunological profile of patients with chronic hepatitis C (CHC) and end-stage renal disease (ESRD) on haemodialysis (HD) is still limited.

AIMS

This study investigated the immune response profile in HCV patients with concomitant ESRD focusing on the influence of the renal disease on the phenotypic profile of peripheral blood lymphocytes.

METHODS

Immunophenotypic features of peripheral blood leucocytes were assessed by flow cytometry in two distinct groups: HCV patients with ESRD (CHC+ESRD, n = 16) and HCV patients with normal renal function (CHC, n = 20). Two control groups that were included were as follows: HCV negative blood donors (BD, n = 15) and HCV negative patients with ESRD (ESRD, n = 19).

RESULTS

Higher frequency of macrophage-like and pro-inflammatory monocytes along with enhanced frequency of CD3(-) CD16(-) CD56(+) , mainly CD56(dim) NK-cells, were the hallmark of CHC+ESRD patients. Lower frequency of B cells with significant decreased of B1 and CD23(+) B-cells were associated with ESRD, regardless the HCV infection. Although higher rates of activated CD4(+) and CD8(+) T cells were observed in the CHC and CHC+ESRD groups, the chemotaxis of T-cell subsets, based on their chemokine receptor expression, was affected by ESRD.

CONCLUSIONS

Chronic hepatitis C patients with ESRD on HD exhibit distinctive phenotypic profile of circulating leucocytes. It may be implicated in the natural history of HCV infection in this particular group of patients and warrants further investigation.

The relationship between psychological factors, inflammation, and nutrition in patients with chronic renal failure undergoing hemodialysis

OBJECTIVE

Hemodialysis has an adverse impact on the immunological, nutritional, and emotional status of patients. The biochemical markers of inflammation and nutrition were studied as well as the relationship of these factors to emotional symptoms.

METHOD

One hundred and ninety-five patients undergoing hemodialysis were enrolled. The mean age was 58.5 years. Emotional symptoms were assessed using the Mini International Neuropsychiatric Interview, Hospital Anxiety and Depression Scale, Chalder Fatigue Scale, and Short-form Health-related Quality of Life. Venus blood was collected for laboratory assessment of serum hemoglobin, albumin, ferritin, C-reactive protein, interleukin (IL) 1beta), IL-6, and tumor necrosis factor alpha.

RESULTS

Among the 195 subjects (92 men and 103 women), 47 (24.1%) fulfilled the criteria for a major depressive disorder (MDD). The IL-6 level in patients with a MDD was significantly higher than in the patients without a MDD. Significant correlation was observed among the following factors: IL-6, fatigue, and quality of life for both physical and mental components. The albumin levels showed a significant correlation with the IL-6 and depression scores.

CONCLUSIONS

These results show that the serum levels of albumin and IL-6 might be laboratory markers associated with the expression of emotional symptoms in patients undergoing hemodialysis. Prospective studies are needed to determine the causal relationships among these variables.

Water quality in conventional and home haemodialysis

Dialysis water can be contaminated by chemical and microbiological factors, all of which are potentially hazardous to patients on haemodialysis. The quality of dialysis water has seen incremental improvements over the years, with advances in water preparation, monitoring and disinfection methods, and high standards are now readily achievable in clinical practice. Advances in dialysis membrane technology have refocused attention on water quality and its potential role in the bioincompatibility of haemodialysis circuits and adverse patient outcomes. The role of ultrapure dialysate is increasingly being advocated, given its proposed clinical benefits and relative ease of production as a result of the widespread use of reverse osmosis and ultrafiltration. Many of the issues pertaining to water quality in hospital-based dialysis units are also pertinent to haemodialysis in the home. Furthermore, an increased awareness of the environmental and financial consequences of home haemodialysis has resulted in the development of automated and more efficient dialysis machines. These new machines have an increased emphasis on water conservation and recycling along with a decreased need for a complex infrastructure for water purification and maintenance.

Emerging importance of residual renal function in end-stage renal failure

Residual renal function (RRF) is well recognized as an important marker of outcomes in peritoneal dialysis (PD), and contributes vitally to solute clearance. Recently, its importance in hemodialysis (HD) has emerged with evidence that it is strongly associated with improved outcomes. The presence of RRF is associated with improved nutrition, reduced erythropoetin requirements, better potassium clearance, and improved quality of life. Retrospective and observational evidence is now available, which suggests that the presence of RRF is independently associated with survival and that this benefit goes beyond what is expected simply from augmentation of small solute clearance. Preservation of RRF is now considered by many to be an important aspect of dialysis strategy. Evidence in favor of one modality over another for preservation of RRF is conflicting, as are the potential benefits of biocompatible fluids in PD. In HD, the evidence in favor of biocompatible membranes is stronger. Emerging evidence is broadly in favor of angiotensin converting enzyme inhibitors for preservation of RRF. Diuretics appear to have a neutral effect. The complexities and practical difficulties in measurement of RRF have resulted in this important parameter being largely ignored in HD. Novel markers of renal function may provide alternative, simple methods of estimating RRF, which may remove the need for urine collections and simplify its measurement.

A comparison of herpes zoster incidence across the spectrum of chronic kidney disease, dialysis and transplantation

BACKGROUND

The effect of different renal replacement therapies on the risk of developing herpes zoster in renal failure patients is unknown. We aimed to investigate the incidence of herpes zoster attack among renal failure patients who were receiving different dialysis modalities, renal transplantation (RT), or not receiving any of the above mentioned therapies yet.

METHODS

A retrospective cohort study of the national health insurance register database was conducted. This observational cohort study involved 79,581 study controls, 15,802 chronic kidney disease patients, 3,694 hemodialysis (HD) patients, 317 peritoneal dialysis (PD) patients, and 159 RT patients.

RESULTS

The RT group had the worst risk of herpes zoster (hazard ratio, HR, 8.46; 95% CI 5.85-12.2), followed by PD (HR 3.61; 95% CI 2.49-4.83) and HD (HR 1.35; 95% CI 1.18-1.55), compared with the comparison group (p < 0.0001). The RT group had also the highest risk of developing herpes zoster with complications among all groups (adjusted HR 15.3). The HRs of the PD group were higher than the HRs of the HD group in terms of herpes zoster or its complications (p < 0.0001 and p = 0.0002, respectively).

CONCLUSIONS

This study suggests that different treatment modalities are associated with different risks of herpes zoster attacks in renal failure patients. PD patients had higher risks than the HD group in terms of herpes zoster or its complications.

Chronic kidney disease worsens sepsis and sepsis-induced acute kidney injury by releasing High Mobility Group Box Protein-1

We have shown that folate-induced kidney dysfunction and interstitial fibrosis predisposes mice to sepsis mortality. Agents that increase survival in normal septic mice were ineffective in a two-stage kidney disease model. Here we used the 5/6 nephrectomy mouse model of progressive chronic kidney disease (CKD) to study how CKD affects acute kidney injury (AKI) induced by sepsis. We induced sepsis using cecal ligation and puncture and found that the presence of CKD intensified the severity of kidney and liver injury, cytokine release, and splenic apoptosis. Accumulation of High Mobility Group Box Protein-1 (HMGB1; a late proinflammatory cytokine released from apoptotic cells), vascular endothelial growth factor (VEGF), tumor necrosis factor (TNF)-α, interleukin (IL)-6, or IL-10 was increased in CKD or sepsis alone and to a greater extent in CKD-sepsis. Only part of the increase was explained by decreased renal clearance. Surprisingly, we found splenic apoptosis in CKD, even in the absence of sepsis. Although VEGF neutralization with soluble fms-like tyrosine kinase 1 (sFLT-1) (a soluble VEGF receptor) effectively treated sepsis, it was ineffective against CKD-sepsis. A single dose of HMGB1-neutralizing antiserum administered 6 h after sepsis alone was ineffective; however, CKD-sepsis was attenuated by anti-HMGB1. Splenectomy transiently decreased circulating HMGB1 levels, reversing the effectiveness of anti-HMGB1 treatment on CKD-sepsis. Thus, progressive CKD increases the severity of sepsis, in part, by reducing the renal clearance of several cytokines. CKD-induced splenic apoptosis and HMGB1 release could be important common mediators for both CKD and sepsis.

Cryoglobulinemia in chronic hemodialysis patients

BACKGROUND

Renal failure patients submitted to chronic hemodialysis can present with cryoglobulinemia. There are few studies on cryoglobulins in chronic hemodialysis patients. The aim of the present study was to determine the prevalence and to identify the components of cryoglobulins in chronic hemodialysis patients.

METHODS

Fifty-four patients on chronic hemodialysis were evaluated for the presence of cryoglobulins, after inclusion and exclusion criteria. The components of the cryoprecipitate were analyzed.

RESULTS

Cryoglobulins were detected in 83% (45/54) of the patients on chronic hemodialysis. The cryoprecipitate was constituted by IgG, IgM, IgA, and complement fractions C3 and C4.

CONCLUSION

We concluded that there was a high prevalence of cryoglobulins in chronic hemodialysis patients, and the cryoprecipitate was constituted by IgG, IgM, IgA, and complement fractions C3 and C4.