Inflammation in end-stage renal disease: sources, consequences, and therapy

Expression of XBP1s in peritoneal mesothelial cells is critical for inflammation-induced peritoneal fibrosis

Intraperitoneal inflammation is the most important determinant of peritoneal fibrosis in patients with long-term peritoneal dialysis (PD). Spliced x-box binding protein-1 (XBP1s), a major proximal effector of unfolded protein response (UPR) signaling, plays an indispensable role in inflammation. Our study demonstrated that the inflammatory factor interleukin-1β (IL-1β) dose- and time-dependently induced XBP1s upregulation and interleukin-6 (IL-6) secretion, as well as the expression of the fibrotic marker fibronectin. However, these effects were prevented by the IRE1 endonuclease inhibitor STF083010 since it time-dependently reduced IL-1β-induced Xbp1 mRNA splicing, XBP1s protein expression, inflammatory factor IL-6 secretion and the expression of the fibrotic marker fibronectin in human peritoneal mesothelial cells (HPMCs). The overexpression and knockdown of XBP1s in HPMCs had a similar effect on fibronectin expression. In a rat model of peritoneal inflammation, STF083010 significantly attenuated chlorhexidine digluconate-induced XBP1s and α-smooth muscle actin expression, as well as fibrotic tissue proliferation, in the peritoneum. Our results suggest that XBP1s is a strong pathogenic factor that mediates inflammation-induced peritoneal fibrosis in peritoneal dialysis.

Higher Cholesterol Level Predicts Cardiovascular Event and Inversely Associates With Mortality in Hemodialysis Patients: 10-Year Outcomes of the Q-Cohort Study

The prevalence of atherosclerotic diseases is higher in hemodialysis patients. The aim of the current study was to investigate associations between cholesterol level and the incidences of cardiovascular disease (CVD) and mortality in hemodialysis patients. A total of 3517 participants undergoing maintenance hemodialysis were followed up for 10 years. Total cholesterol (TC) level was divided into quartile in baseline data. The multivariate analyses were calculated by a Cox proportional hazards model. The incidences of ischemic heart disease (IHD), peripheral artery disease (PAD), and CVD were significantly positively associated with higher cholesterol levels after adjustment for confounding factors (P < 0.01, P = 0.04, and P < 0.01, respectively). Furthermore, the incidences of cancer-associated mortality and all-cause mortality were significantly positively associated with lower cholesterol levels after adjustment for confounding factors (both P < 0.01). The lowest TC level at all-cause mortality risk was 179 mg/dL. From these results, higher TC predicts IHD, PAD, and CVD events, and lower TC predicts cancer-associated mortality and all-cause mortality in patients undergoing maintenance hemodialysis.

Oxidative Status before and after Renal Replacement Therapy: Differences between Conventional High Flux Hemodialysis and on-Line Hemodiafiltration

Hemodialysis patients experience high oxidative stress because of systemic inflammation and depletion of antioxidants. Little is known about the global oxidative status during dialysis or whether it is linked to the type of dialysis. We investigated the oxidative status before (pre-) and after (post-) one dialysis session in patients subjected to high-flux dialysis (HFD) or on-line hemodiafiltration (OL-HDF). We analyzed carbonyls, oxidized LDL (oxLDL), 8-hydroxy-2′-deoxyguanosine, and xanthine oxidase (XOD) activity as oxidative markers, and total antioxidant capacity (TAC), catalase, and superoxide dismutase activities as measures of antioxidant defense. Indices of oxidative damage (OxyScore) and antioxidant defense (AntioxyScore) were computed and combined into a global DialysisOxyScore. Both dialysis modalities cleared all markers (p < 0.01) except carbonyls, which were unchanged, and oxLDL, which increased post-dialysis (p < 0.01). OxyScore increased post-dialysis (p < 0.001), whereas AntioxyScore decreased (p < 0.001). XOD and catalase activities decreased post-dialysis after OL-HDF (p < 0.01), and catalase activity was higher after OL-HDF than after HFD (p < 0.05). TAC decreased in both dialysis modalities (p < 0.01), but remained higher in OL-HDF than in HFD post-dialysis (p < 0.05), resulting in a lower overall DialysisOxyScore (p < 0.05). Thus, patients on OL-HDF maintain higher levels of antioxidant defense, which might balance the elevated oxidative stress during dialysis, although further longitudinal studies are needed.

Assessment of Malnutrition Inflammation Score in Different Stages of Chronic Kidney Disease

BACKGROUND

Protein-energy wasting (PEW) is common in patients with chronic kidney disease (CKD), and is associated with high morbidity and mortality. Malnutrition-Inflammation Score (MIS) has significant correlations with prospective hospitalization and mortality, as well as measures of anemia, inflammation, and nutrition in dialysis patients.

MATERIAL AND METHODS

The study was conducted on 100 adult patients of CKD selected from K&D clinic PGIMS, Rohtak. All the patients went under detailed socioeconomic, clinical, biochemical and radiological examination. The average of three measurements of body weight, height, triceps skin fold thickness (TST), and mid-arm muscle circumference (MAMC) were measured in all patients. MIS was calculated for all the patients.

RESULTS

Out of total 100 patients, 64 were male and 36 were female. Overall, the prevalence of malnutrition was 60%. A total of 42%, 16% and 2% patients had mild, moderate and severe malnutrition respectively. Our study also shows significant association between staging of CKD (3 to 5-D) and MIS. A significant negative correlation was found between MIS and factors such as BMI, eGFR, serum calcium and hemoglobin levels. A significant positive correlation of this score was found with blood urea serum creatinine, serum uric acid, serum potassium and serum phosphate. Multivariate analysis showed significant association between MIS and serum albumin, TIBC, BMI, family income and hs-CRP.

CONCLUSION

Assessment of key components of malnutrition and inflammation early in disease course will help to identify high risk subjects in whom modifying these predictors will help in providing active and healthy life for CKD patients.

Efficacy of Polyunsaturated Fatty Acids on Inflammatory Markers in Patients Undergoing Dialysis: A Systematic Review with Network Meta-Analysis of Randomized Clinical Trials

The effects of polyunsaturated fatty acids (PUFAs) on inflammatory markers among patients receiving dialysis have been discussed for a long time, but previous syntheses made controversial conclusion because of highly conceptual heterogeneity in their synthesis. Thus, to further understanding of this topic, we comprehensively gathered relevant randomized clinical trials (RCTs) before April 2019, and two authors independently extracted data of C-reactive protein (CRP), high-sensitivity C-reactive protein (hs-CRP), and interleukin-6 (IL-6) for conducting network meta-analysis. Eighteen eligible RCTs with 962 patients undergoing dialysis were included in our study. The result showed that with placebo as the reference, PUFAs was the only treatment showing significantly lower CRP (weighted mean difference (WMD): −0.37, 95% confidence interval (CI): −0.07 to −0.68), but the CRP in PUFAs group was not significantly lower than vitamin E, PUFAs plus vitamin E, or medium-chain triglyceride. Although no significant changes were noted for hs-CRP and IL-6 levels, PUFAs showed the best ranking among treatments according to surface under the cumulative ranking. Therefore, PUFAs could be a protective option for patients receiving dialysis in clinical practice.

Long Pentraxin 3 as a Broader Biomarker for Multiple Risk Factors in End-Stage Renal Disease: Association with All-Cause Mortality

Persistent inflammation in end-stage renal disease (ESRD) patients is known to underlie the progression of chronic kidney disease and to be associated with multiple risk factors including malnutrition, atherosclerosis, and cardiovascular disease (CVD). The acute-phase protein pentraxin 3 (PTX3) has a proven potential as a local inflammatory biomarker, but its clinical utility in ESRD remains unclear. Circulating levels of PTX3 and classical inflammatory mediators, including the clinical prototypical C-reactive protein (CRP), were assessed in 246 ESRD patients on dialysis and analysed in relation to the lipid profile, adipokine levels, and nutritional, cardiac, and renal fibrosis markers. Occurrence of deaths was recorded for the following year. Contrarily to the classical inflammatory markers, PTX3 levels were negatively correlated with nutritional markers and associated with a less atherogenic lipid profile. Levels of the cardiac and renal fibrosis markers and of the oxidized LDL/LDL-C ratio were found to be independent determinants of PTX3 concentration. When comparing inflammatory mediators, the increase in the PTX3 levels was the only predictor of all-cause mortality in dialysis patients in a survival model adjusted to all markers under study, other than the inflammatory ones, besides common confounding factors in dialysis. Data support the clinical applicability of PTX3 as a broader inflammatory biomarker than the classical ones, presenting a close association with inflammation, malnutrition, CVD, and renal fibrosis and a great potential to predict all-cause mortality in dialysis patients. The pleiotropic character of PTX3 may be of clinical relevance, and it could be targeted to ameliorate the high morbidity and mortality associated with ESRD.

Mitochondrial Activity and Skeletal Muscle Insulin Resistance in Kidney Disease

Insulin resistance is a key feature of the metabolic syndrome, a cluster of medical disorders that together increase the chance of developing type 2 diabetes and cardiovascular disease. In turn, type 2 diabetes may cause complications such as diabetic kidney disease (DKD). Obesity is a major risk factor for developing systemic insulin resistance, and skeletal muscle is the first tissue in susceptible individuals to lose its insulin responsiveness. Interestingly, lean individuals are not immune to insulin resistance either. Non-obese, non-diabetic subjects with chronic kidney disease (CKD), for example, exhibit insulin resistance at the very onset of CKD, even before clinical symptoms of renal failure are clear. This uraemic insulin resistance contributes to the muscle weakness and muscle wasting that many CKD patients face, especially during the later stages of the disease. Bioenergetic failure has been associated with the loss of skeletal muscle insulin sensitivity in obesity and uraemia, as well as in the development of kidney disease and its sarcopenic complications. In this mini review, we evaluate how mitochondrial activity of different renal cell types changes during DKD progression, and discuss the controversial role of oxidative stress and mitochondrial reactive oxygen species in DKD. We also compare the involvement of skeletal muscle mitochondria in uraemic and obesity-related muscle insulin resistance.

Impact of sarcopenia on long-term mortality and cardiovascular events in patients undergoing hemodialysis

BACKGROUND/AIMS

A high body mass index (BMI) is known to correlate with better survival in patients on hemodialysis (HD). However, the impacts of body composition and sarcopenia on survival have not been well studied in this population.

METHODS

One hundred and forty-two prevalent HD patients were recruited and followed prospectively for up to 4.5 years. Low muscle mass (measured using a portable, whole-body, bioimpedance spectroscopic device) was defined as a lean tissue index (LTI) two standard deviations (SD) or more below the normal gender-specific mean for young people. Low muscle strength was a handgrip strength (HGS) of less than 30 kg in males and less than 20 kg in females. Sarcopenia was considered present when both LTI and HGS were reduced.

RESULTS

The mean age was 59.8 ± 13.1 years; 57.0% were male and 47.2% had diabetes. Forty-seven patients (33.1%) had sarcopenia. During follow-up, 28 patients (19.7%) died, and low LTI (adjusted hazard ratio [HR], 2.77; 95% confidence interval [CI], 1.10 to 6.97) and low HGS (HR 5.65; 95% CI, 1.99 to 16.04) were independently associated with mortality. Sarcopenia was a significant predictor for death (HR, 6.99; 95% CI, 1.84 to 26.58; p = 0.004) and cardiovascular events (HR, 4.33; 95% CI, 1.51 to 12.43; p = 0.006).

CONCLUSION

Sarcopenia was strongly associated with long-term mortality and cardiovascular events in HD patients. Assessment of muscle strength and muscle mass may provide additional prognostic information to survival in patients with end-stage renal disease.

Injury derived autoimmunity: Anti-perlecan/LG3 antibodies in transplantation

Ischemic, immunologic or pharmacological stressors can induce vascular injury and endothelial apoptosis in organ donors, in transplant candidates due to the impact of end stage organ failure on the vasculature, and in association with peri-transplantation events. Vascular injury may shape innate and adaptive immune responses, leading to dysregulation in the balance between tolerance and immunoreactivity to vascular-derived antigens. Mounting evidence shows that the early stages of apoptosis, characterized by the absence of membrane permeabilization, are prone to trigger various modes of intercellular communication allowing neoantigen production, exposure, or both. In this review, we present the evidence for the release of LG3, an immunogenic fragment of perlecan, as a consequence of caspase-3 dependent vascular apoptosis leading to the genesis of anti-LG3 autoantibodies and the consequences of these autoantibodies in native and transplanted kidneys.

IL 6 but not TNF is linked to coronary artery calcification in patients with chronic kidney disease

INTRODUCTION

Patients with chronic kidney disease (CKD) have a high risk of death mainly due to cardiovascular diseases (CVD). Early risk identification may allow interventions and prevention of fatal events.

OBJECTIVES

The study aim was to assess the usefulness of selected CVD biomarkers as predictors of 5-year mortality in patients with different CKD stages.

PATIENTS AND METHODS

Study included 57 CKD patients: 38 in stage 5 (ESRD), 19 in stage 3 and 4 (CKD3-4), and 19 healthy controls. Blood samples were obtained once to measure fetuin A, adiponectin, leptin, tumor necrosis factor (TNF), interleukin-6 (IL-6), metalloproteinase-9 (MMP9), intracellular-1 (ICAM1) and vascular-1 (VCAM1) adhesion molecules (ELISA or Luminex platform). Computed tomography was performed to assess the calcium score (CS). Patients were prospectively followed for 5 years to evaluate their all-cause mortality.

RESULTS

Serum VCAM1, TNF and IL-6 were significantly higher in more advanced CKD stages. VCAM1 correlated significantly with ICAM1, TNF and IL-6. TNF and IL-6 were also significantly correlated with each other. No significant changes were detected for other markers. IL-6 correlated significantly with CS, age, renal function and CRP. Elevated CS and IL-6 increased over 3 times the 5-year all-cause and cardiovascular mortality risks in patients with CKD or ESRD at baseline.

CONCLUSIONS

IL-6 and CS were significantly associated with 5-year risk of all-cause mortality in CKD patients. Our study suggests an involvement of chronic inflammation linked to coronary artery calcification that is likely to contribute to the cardiovascular mortality in patients with impaired renal function.

New insights into immune mechanisms of antiperlecan/LG3 antibody production: Importance of T cells and innate B1 cells

Autoantibodies against perlecan/LG3 (anti-LG3) have been associated with increased risks of delayed graft function, acute rejection, and reduced long-term survival. High titers of anti-LG3 antibodies have been found in de novo renal transplants recipients in the absence of allosensitizing or autoimmune conditions. Here, we seek to understand the pathways controlling anti-LG3 production prior to transplantation. Mice immunized with recombinant LG3 produce concomitantly IgM and IgG anti-LG3 antibodies suggesting a memory response. ELISpot confirmed the presence of LG3-specific memory B cells in nonimmunized mice. Purification of B1 and B2 subtypes identified peritoneal B1 cells as the major source of memory B cells reactive to LG3. Although nonimmunized CD4-deficient mice were found to express LG3-specific memory B cells, depletion of CD4⁺ T cells in wild type mice during immunization significantly decreased anti-LG3 production. These results demonstrate that B cell memory to LG3 is T cell independent but that production of anti-LG3 antibodies requires T cell help. Further supporting an important role for T cells in controlling anti-LG3 levels, we found that human renal transplant recipients show a significant decrease in anti-LG3 titers upon the initiation of CNI-based immunosuppression. Collectively, these results identify T cell targeting interventions as a means of reducing anti-LG3 levels in renal transplant patients.

The Effects of OMEGA-3 Fatty Acid Supplementation Upon Interleukin-12 and Interleukin-18 in Chronic Kidney Disease Patients

OBJECTIVE(S)

Cardiovascular disease (CVD) remains a leading cause of mortality in chronic kidney disease (CKD) patients. Interventions targeting traditional risk factors have largely proven ineffective in CKD patients in part because of the increased role of nontraditional risk factors such as chronic inflammation. Omega-3 fatty acids (ω3FA) are inexpensive and safe natural agents, which target inflammation and have potential cardioprotective benefits. The aim of the study was to determine the effects of ω3FA supplementation upon serum interleukin (IL)-12, IL-18, and highly sensitive C-reactive protein (hsCRP) in patients with Stage 3-4 CKD.

METHODS

We performed a post-hoc analysis of a randomized placebo-controlled trial in 73 nondiabetic CKD patients to determine the effects of ω3FA supplementation (4 g daily for 8 weeks) upon serum levels of IL-12, IL-18, and hsCRP.

RESULTS

There were no preintervention differences in IL-12, IL-18, or hsCRP between treatment groups. Postintervention levels of IL-12, IL-18, and hsCRP were similar between the treatment groups. However, IL-12 and IL-18 increased in both treatment groups over the intervention period, whereas hsCRP remained unchanged. The magnitude of increase in serum IL-18 (ΔIL-18) was significantly less in participants in the ω3FA treatment group compared to placebo (P = .047).

CONCLUSION(S)

This study has shown that 4 g daily ω3FA supplementation may lower serum IL-18 levels in patients with moderate CKD. Although there were no apparent effects on several other markers of inflammation, this study provides evidence for a specific effect of ω3FA on inflammatory pathways.

Importance of Mean Platelet Volume in Predicting Cardiac Mechanics Parameters and Carotid-Intima Media Thickness in Children With End-Stage Renal Disease and Comparison With Healthy Children

Cardiovascular disease (CVD) is the major cause of death in children with ESRD. Echocardiography and Doppler ultrasound are useful devices for diagnosing cardiovascular abnormalities in such patients. However, they are expensive, difficult to perform as a routine, and not available in many centers. Therefore, finding a more accessible and inexpensive method for CVD evaluation biomarkers is needed. The aim of this study was to evaluate the relationship between mean platelet volume (MPV) as a routine hematological parameter with cardiac mechanics characteristics in children with ESRD. Forty-two children under dialysis and 60 age- and sex-matched healthy subjects as control group were enrolled in the study. Carotid-intima media thickness (CIMT) and echocardiographic parameters were measured in both groups. In addition, hematological and biochemical variables were evaluated in blood samples of participants. MPV was significantly higher in patients than in controls. CIMT, left ventricular mass index (LVMI), end diastolic diameter, strain rate, and global longitudinal strain were significantly different between the two groups. MPV was positively correlated with LVMI and inversely with ejection fraction. In receiver operating characteristic (ROC) curve analysis, the area under the ROC curve (AUC) values for MPV in predicting left ventricular hypertrophy (LVH) and abnormal CIMT were 0.65 (P = 0.07) and 0.53 (P = 0.74), respectively. MPV was correlated with some cardiac abnormalities in children with ESRD. However, it could not show appropriate predictive values in diagnosing LVH and subclinical atherosclerosis. Further studies with prospective design could shed more light in this topic.

Endotoxin removal from aqueous solutions with dimethylamine-functionalized graphene oxide: Modeling study and optimization of adsorption parameters

Novel graphene oxide (GO)-based adsorbent embedded with epichlorohydrin (ECH) as a coupling agent and dimethylamine (DMA) as a ligand (GO-ECH-DMA) were prepared and employed for endotoxin removal from aqueous solutions. The physicochemical properties of nanocomposite were fully characterized. The model attributed to batch adsorption process was optimized employing response surface methodology (RSM) via various parameters such as pH, GO-ECH-DMA dosage, and contact time and endotoxin concentration. The p-value with low probability (<0.00001), determination coefficient (R²=0.99) and the non-significant lack of fit (p > 0.05) showed a quadratic model with a good fit with experimental terms. The synergistic effects of the linear term of contact time and GO-ECH-DMA dosage on endotoxin removal were significant. The optimum condition for endotoxin removal was obtained at pH of 5.52, GO-ECH-DMA dosage of 21 mgL^-1, contact time of 56 min and endotoxin concentration of 51.3 endotoxin units per milliliter (EUmL^-1). The equilibrium was the better explained by Langmuir isotherm with the maximum monolayer adsorption capacity of 121.47 EUmg-1, while the kinetics of the endotoxin adsorption process was followed by the pseudo-second-order model. The adsorbent could be recycled with NaOH. The possible mechanisms of endotoxin adsorption were proposed by hydrogen-bonding, π-π stacking, and electrostatic interaction.

Understanding and managing atherosclerotic renovascular disease: still a work in progress

Atherosclerotic renovascular disease (ARVD) is an unresolved therapeutic dilemma despite extensive pre-clinical and clinical studies. The pathophysiology of the disease has been widely studied, and many factors that may be involved in progressive renal injury and cardiovascular risk associated with ARVD have been identified. However, therapies and clinical trials have focused largely on attempts to resolve renal artery stenosis without considering the potential need to treat the renal parenchyma beyond the obstruction. The results of these trials show a staggering consistence: although nearly 100% of the patients undergoing renal angioplasty show a resolution of the vascular obstruction, they do not achieve significant improvements in renal function or blood pressure control compared with those patients receiving medical treatment alone. It seems that we may need to take a step back and reconsider the pathophysiology of the disease in order to develop more effective therapeutic strategies. This mini-review discusses potential therapeutic alternatives that focus on the renal parenchyma distal to the vascular obstruction and may provide additional tools to enhance current treatment of ARVD.

Validation of a Novel Modified Aptamer-Based Array Proteomic Platform in Patients with End-Stage Renal Disease

End stage renal disease (ESRD) is characterized by complex metabolic abnormalities, yet the clinical relevance of specific biomarkers remains unclear. The development of multiplex diagnostic platforms is creating opportunities to develop novel diagnostic and therapeutic approaches. SOMAscan is an innovative multiplex proteomic platform which can measure >1300 proteins. In the present study, we performed SOMAscan analysis of plasma samples and validated the measurements by comparison with selected biomarkers. We compared concentrations of SOMAscan-measured prostate specific antigen (PSA) between males and females, and validated SOMAscan concentrations of fibroblast growth factor 23 (FGF23), FGF receptor 1 (FGFR1), and FGFR4 using Enzyme-Linked immunosorbent assay (ELISA). The median (25th and 75th percentile) SOMAscan PSA level in males and females was 4304.7 (1815.4 to 7259.5) and 547.8 (521.8 to 993.4) relative fluorescence units (p = 0.002), respectively, suggesting biological plausibility. Pearson correlation between SOMAscan and ELISA was high for FGF23 (R = 0.95, p < 0.001) and FGFR4 (R = 0.69, p < 0.001), indicating significant positive correlation, while a weak correlation was found for FGFR1 (R = 0.13, p = 0.16). In conclusion, there is a good to near-perfect correlation between SOMAscan and standard immunoassays for FGF23 and FGFR4, but not for FGFR1. This technology may be useful to simultaneously measure a large number of plasma proteins in ESRD, and identify clinically important prognostic markers to predict outcomes.

Supplementation of Short-Chain Fatty Acid, Sodium Propionate, in Patients on Maintenance Hemodialysis: Beneficial Effects on Inflammatory Parameters and Gut-Derived Uremic Toxins, A Pilot Study (PLAN Study)

BACKGROUND

In end-stage renal disease (ESRD), gut-derived uremic toxins play a crucial role in the systemic inflammation and oxidative stress promoting the excess morbidity and mortality. The biochemical derangement is in part a consequence of an insufficient generation of short-chain fatty acids (SCFA) due to the dysbiosis of the gut and an insufficient consumption of the fermentable complex carbohydrates.

AIM OF THE STUDY

The primary end-point was to evaluate the potential efficacy of SCFA (specifically, sodium propionate (SP)) for patients on maintenance hemodialysis (MHD) on systemic inflammation. Secondary end-points included potential attenuation of oxidative stress markers, insulin resistance and production of gut-derived uremic toxins indoxyl sulfate and p-cresol sulfate, as well as health status after SP supplementation.

STUDY DESIGN

We performed a single-center non-randomized pilot study in 20 MHD patients. They received the food additive SP with a daily intake of 2 × 500 mg in the form of capsules for 12 weeks. Pre-dialysis blood samples were taken at the beginning, after six weeks and at the end of the administration period, as well as four weeks after withdrawal of the treatment.

RESULTS

The subjects revealed a significant decline of inflammatory parameters C-reactive protein (-46%), interleukin IL-2 (-27%) and IL-17 (-15%). The inflammatory parameters IL-6 and IFN-gamma showed a mild non-significant reduction and the anti-inflammatory cytokine IL-10 increased significantly (+71%). While the concentration of bacterial endotoxins and TNF-α remained unchanged, the gut-derived uremic toxins, indoxyl sulfate (-30%) and p-cresyl sulfate (-50%), revealed a significant decline. The SP supplementation reduced the parameters of oxidative stress malondialdehyde (-32%) and glutathione peroxidase activity (-28%). The serum insulin levels dropped by 30% and the HOMA-index by 32%. The reduction of inflammatory parameters was associated with a lowering of ferritin and a significant increase in transferrin saturation (TSAT). Four weeks after the end of the treatment phase, all improved parameters deteriorated again. Evaluation of the psycho-physical performance with the short form 36 (SF-36) questionnaire showed an enhancement in the self-reported physical functioning, general health, vitality and mental health. The SP supplementation was well tolerated and without important side effects. No patient had left the study due to intolerance to the medication. The SP supplementation in MHD patients reduced pro-inflammatory parameters and oxidative stress and improved insulin resistance and iron metabolism. Furthermore, SP effectively lowered the important gut-derived uremic toxins indoxyl and p-cresol sulfate. These improvements were associated with a better quality of life. Further controlled studies are required in a larger cohort to evaluate the clinical outcome.

Relationship between pulse pressure and inflammation with left ventricular diastolic dysfunction in chronic kidney disease patients

BACKGROUND

Diastolic dysfunction (DD) is an important cause of cardiovascular disease (CVD) mortality in chronic kidney disease (CKD) patients. Non-traditional risk factors, such as arterial stiffness and inflammation, are implicated in the pathogenesis of DD in CKD patients.

AIM

To determine the association between inflammatory markers (interleukin (IL)-12, IL-18, highly sensitive C-reactive protein (hsCRP)) and non-invasive markers of arterial stiffness (24-h pulse pressure (PP)) with DD in stages 3-4 CKD patients.

METHODS

We performed a sub-analysis of 78 non-diabetic stages 3-4 CKD subjects to determine the relationship between 24-h PP, IL-12, IL-18 and hsCRP with DD.

RESULTS

DD was present in 38 subjects (49%). Subjects with DD were significantly older (61.0 ± 1.9 vs 50.2 ± 2.0 years; P < 0.001) and had higher 24-h PP (48(95% confidence interval 45, 52) vs 43(95% confidence interval 41, 45) mmHg; P < 0.005); 24-h PP was associated with DD (P = 0.02), but this was no longer significant after adjustment for age (P = 0.31). Serum IL-12, IL-18 and hsCRP levels were not significantly different between subjects with or without DD.

CONCLUSION

Asymptomatic subclinical DD was present in 50% of a cohort of stages 3-4 CKD patients but was not associated with IL-12, IL-18 or hsCRP. The association between 24-h PP and DD was no longer apparent following adjustment for age, but given the small sample size, our findings will need to be explored in larger-sized cohorts of individuals with moderate-stage CKD.

Inflammation down-regulates CYP3A4-catalysed drug metabolism in hemodialysis patients

Background

Recent studies indicate that inflammation may also affect CYP3A4 activity. Associations of CYP3A4-mediated metabolism of quinine, with inflammatory biomarkers were investigated in patients undergoing maintenance hemodialysis (HD).

Methods

A single dose of 100 mg quinine was given to 44 HD patients and the plasma concentration of quinine and its metabolite 3-OH-quinine were measured 12 h after drug intake. The ratios of quinine/3-OH-quinine and 4β-OH-cholesterol/cholesterol were used as markers of CYP3A4 activity. Inflammatory biomarkers, high-sensitive CRP (hsCRP), pentraxin 3 (PTX3) and orosomucoid were followed during 4 weeks prior to quinine administration.

Results

The quinine/3-OH-quinine ratio correlated with median concentrations of hsCRP (Rho = 0.48; p = 0.001) and orosomucoid (Rho = 0.44; p = 0.003), and also with interleukin-6 at 12 h after drug intake (Rho = 0.43; P = 0.004) but not PTX3. In multivariate regression analysis, the correlation between CYP3A4 activity and median hsCRP remained borderline significant (p = 0.05). 4β-OH-cholesterol/cholesterol ratio correlated with quinine/3-OH-quinine (p = 0.008), but not with any of the inflammation markers.

Conclusions

The association between CYP3A4 activity and inflammatory biomarkers suggest that the activity of CYP3A4 is reduced by inflammation in HD patients. Further studies are needed to confirm this finding and to assess to what extent magnitude and duration of inflammation as well as the microbiota affect drug metabolism.

CD19+ B-Cells, a New Biomarker of Mortality in Hemodialysis Patients

Background and objectives

Mortality of patients on hemodialysis (HD) remains very high despite recent improvements in HD techniques. Cardiovascular (CV) complications and infections are the main causes of death. Some studies suggest that disturbances in the immune system could play a role in this disproportionate mortality, through the links of immunity with inflammation and propensity to infections. However, few studies have addressed the role of lymphocyte populations and the global and CV mortality of HD patients.

Aim

To analyze the relationship of peripheral blood lymphocyte populations (PBLP) and all-cause and CV mortality of HD patients.

Design, setting, participants, and measurements

We design a prospective observational single center study in a cohort of HD prevalent patients. PBLP were analyzed at baseline and after 1 year and patients were followed for a 5-year period. Main outcomes were all-cause and CV mortality.

Results

One hundred and four patients (51% male, mean age 64.8 ± 15 years) were included. Follow-up was 18 (7–47) months. Fifty-five patients (52.8%) died, main causes of death being CVD (40%) and infections (29.1%). Low total lymphocyte counts were found in 47 patients (45.2%), and the most frequency lymphopenias were CD19⁺ B-cell (57.7%), CD3⁺ (40.4%), and CD4⁺ (36.5%). After 1 year, all determinations were lower except CD56⁺CD16⁺CD3⁻ natural killer. Patient survival was significantly lower in patients with a CD19⁺ B-cell count < 100 cells/μL at baseline as compared to patients with CD19⁺ B-cell ≥ 100 cells/μL counts at the end of follow-up (16.5 vs 54%, p = 0.003). By multivariable analysis, age, history of CV disease, Charlson index, a KT/V < 1.2, and a CD19⁺ B-cell count < 100 cells/μL at baseline and after 1-year were factors associated with of all-cause mortality. A CD19⁺ B-cell count < 100 cells/μL at baseline was associated with CV mortality.

Conclusion

CD19⁺ B-cell lymphopenia is very common among HD patients, and it could be an independent predictor of all-cause and CV mortality. More studies are needed to confirm these findings.

Soluble Urokinase Plasminogen Activator Receptor (suPAR) and All-Cause and Cardiovascular Mortality in Diverse Hemodialysis Patients

Introduction

The soluble receptor of urokinase plasminogen activator (suPAR) is an innate immunity/inflammation biomarker predicting cardiovascular (CV) and non-CV events in various conditions, including type 2 diabetic patients on dialysis. However, the relationship between suPAR and clinical outcomes in the hemodialysis population at large has not been tested.

Methods

We measured plasma suPAR levels (R&D enzyme-linked immunosorbent assay [ELISA]) in 1038 hemodialysis patients with a follow-up of 2.9 years (interquartile range = 1.7−4.2) who were enrolled in the PROGREDIRE study, a cohort study involving 35 dialysis units in 2 regions in Southern Italy.

Results

suPAR was strongly (P < 0.001) and independently related to female gender (β = −0.160), age (β = 0.216), dialysis vintage (β = 0.264), CV comorbidities (β = 0.105), alkaline phosphatase (β = 0.136), albumin (β = −0.147), and body mass index (BMI; β = 0.174) (all P < 0.006). In fully adjusted analyses, suPAR tertiles predicted the risk of all-cause mortality (third tertile vs. first tertile hazard ratio (HR) = 1.91, 95% confidence interval (CI) = 1.47 – 2.48, P < 0.001), CV mortality (HR = 1.47, 95% CI = 1.03–2.09, P = 0.03), and non-CV mortality (HR = 1.94, 95% CI = 1.28–2.93, P = 0.002); these relationships were not modified by diabetes or other risk factors. suPAR added only modest prognostic risk discrimination and reclassification power for these outcomes to parsimonious models based on simple clinical variables.

Conclusion

In conclusion, suPAR robustly predicted all-cause and both CV and non-CV mortality in a large unselected hemodialysis population. Intervention studies are needed to definitively test the hypothesis that suPAR is causally implicated in clinical outcomes in this population.

A translational model of chronic kidney disease in swine

Animal models of chronic kidney disease (CKD) are critical for understanding its pathophysiology and for therapeutic development. The cardiovascular and renal anatomy and physiology of the pig are virtually identical to humans. This study aimed to develop a novel translational model of CKD that mimics the pathological features of CKD in humans. CKD was induced in seven domestic pigs by bilateral renal artery stenosis and diet-induced dyslipidemia. Animals were observed for a total of 14 wk. Renal hemodynamics and function were quantified in vivo using multi-detector CT after 6, 10, and 14 wk of CKD. Urine and blood were collected at each time-point, and blood pressure was continuously measured (telemetry). After completion of in vivo studies, pigs were euthanized, kidneys were removed, and microvascular (MV) architecture (μCT), markers of renal injury, inflammation, and fibrosis were evaluated ex vivo. Additional pigs were used as controls ( n = 7). Renal blood flow and glomerular filtration were reduced by 50% in CKD, accompanied by hypertension and elevated plasma creatinine, albumin-to-creatinine ratio and increased urinary KIM-1 and NGAL, suggesting renal injury. Furthermore, 14 wk of CKD resulted in cortical and medullary MV remodeling and loss, inflammation, glomerulosclerosis, tubular atrophy, and tubule-interstitial fibrosis compared with controls. The current study characterizes a novel model of CKD that mimics several of the pathological features observed in human CKD, irrespective of the etiology. Current approaches only slow rather than halt CKD progression, and this novel model may offer a suitable platform for the development of new treatments in a translational fashion.

Efficacy of Nutritional Interventions on Inflammatory Markers in Haemodialysis Patients: A Systematic Review and Limited Meta-Analysis

Low-grade chronic inflammation is prevalent in patients undergoing haemodialysis (HD) treatment and is linked to the development of premature atherosclerosis and mortality. The non-pharmacological approach to treat inflammation in HD patients through nutritional intervention is well cited. We aimed to assess the efficacy of different nutritional interventions at improving inflammatory outcomes in HD patients, based on markers such as C-reactive protein (CRP), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α). We searched PubMed, Cochrane Library, and Embase for randomized controlled trials (RCT) published before June 2017. Inclusion criteria included RCTs on adult patients on maintenance HD treatment with duration of nutritional interventions for a minimum 4 weeks. Risk of bias was assessed using the Jadad score. In total, 46 RCTs experimenting different nutritional interventions were included in the review and categorized into polyphenols rich foods, omega-3 fatty acids, antioxidants, vitamin D, fibres, and probiotics. Meta-analyses indicated significant reduction in CRP levels by omega-3 fatty acids (Random model effect: -0.667 mg/L, p < 0.001) and vitamin E (fixed model effect: -0.257 mg/L, p = 0.005). Evidence for other groups of nutritional interventions was inconclusive. In conclusion, our meta-analysis provided evidence that omega-3 fatty acids and vitamin E could improve inflammatory outcomes in HD patients.

Links between a biomarker profile, cold ischaemic time and clinical outcome following simultaneous pancreas and kidney transplantation

In sepsis, trauma and major surgery, where an explicit physiological insult leads to a significant systemic inflammatory response, the acute evolution of biomarkers have been delineated. In these settings, Interleukin (IL) -6 and TNF-α are often the first pro-inflammatory markers to rise, stimulating production of acute phase proteins followed by peaks in anti-inflammatory markers. Patients undergoing SPKT as a result of diabetic complications already have an inflammatory phenotype as a result of uraemia and glycaemia. How this inflammatory response is affected further by the trauma of major transplant surgery and how this may impact on graft survival is unknown, despite the recognised pro-inflammatory cytokines' detrimental effects on islet cell function. The aim of the study was to determine the evolution of biomarkers in omentum and serum in the peri-operative period following SPKT. The biochemical findings were correlated to clinical outcomes. Two omental biopsies were taken (at the beginning and end of surgery) and measured for CD68+ and CD206+ antibodies (M1 and M2 macrophages respectively). Serum was measured within the first 72 h post-SPKT for pro- and anti-inflammatory cytokines (IL -6, -10 and TNF-α), inflammatory markers (WCC and CRP) and endocrine markers (insulin, C-peptide, glucagon and resistin). 46 patients were recruited to the study. Levels of M1 (CD68+) and M2 (CD206+) macrophages were significantly raised at the end of surgery compared to the beginning (p = 0.003 and p < 0.001 respectively). Levels of C-peptide, insulin and glucagon were significantly raised 30 min post pancreas perfusion compared to baseline and were also significantly negatively related to prolonged cold ischaemic time (CIT) (p < 0.05). CRP levels correlated significantly with the Post-Operative Morbidity Survey (p < 0.05). The temporal inflammatory marker signature after SPKT is comparable to the pattern observed following other physiological insults. Unique to this study, we find that CIT is significantly related to early pancreatic endocrine function. In addition, this study suggests a predictive value of CRP in peri-operative morbidity following SPKT.

The Role of Improved Water Quality on Inflammatory Markers in Patients Undergoing Regular Dialysis

Hemodialysis utilizes large quantities of water for the preparation of dialysis fluid. Such water meets national standards and international standards but a considerable disparity exists between such standards with respect to microbiological purity. This study collated and retrospectively analyzed the impact of upgrading water systems from that specified in the US standards to those specified in European standards on clinical measures associated with inflammation in four metropolitan dialysis units for two periods. Two periods were compared, three months prior to and six months post upgrading the water treatment systems. The monthly total erythropoietin dosage and intravenous iron supplementation for each patient were also compared over these periods. Variables with significant pre-post differences were assessed using multivariate models to control for confounding factors.

The results indicated significant increases in hemoglobin, ferritin and TSat (all p < 0.0001) and albumin (p = 0.0001) were associated with improvement in water quality. Decreases in CRP and creatinine (both p < 0.0001) were also noted.

These findings suggest that the current regulations in the United States set the microbiological limits of water and dialysis fluid inappropriately high, and the limits should be revised downwards, since such an approach is reflected in improvement in markers of inflammation.

Prevalence of Periodontitis in Patients Undergoing Hemodialysis: a Case Control Study

Objectives:

To assess the prevalence of periodontal disease among patients undergoing renal dialysis.

Methods:

Sixty hemodialysis patients (30 males, 30 females) with a mean age of 44.4±9.5 years comprised the study group. Periodontal parameters such as plaque index (PI), bleeding on probing (BOP), probing pocket depth (PPD) and clinical attachment level (CAL) were measured in these patients and 60 age and sex-matched control subjects. The data was tabulated and analyzed.

Results:

The mean duration of dialysis was 5.50±3.02 years. The plaque index (PI) bleeding on probing (BOP), Periodontal probing depth (PPD) and clinical attachment level (CAL) were significantly higher in patients undergoing hemodialysis than in control subjects. The mean clinical attachment level was significantly higher among the dialysis patients (2.78±0.83 mm) than the control subjects (1.97±0.53 mm). The plaque index and bleeding on probing also showed a similar pattern in patients undergoing hemodialysis compared to control patients. The prevalence and severity of periodontal disease seems to be higher in patients undergoing dialysis.

Conclusion:

From the observations of this study, it can be concluded that patients undergoing hemodialysis are more prone to periodontal diseases. Further studies with a larger population and a comparison with the duration of dialysis may further substantiate the current findings.

The prevalence and association of chronic kidney disease and diabetes in liver cirrhosis using different estimated glomerular filtration rate equation

Background

Chronic kidney disease (CKD) in cirrhosis is one of the dreaded complications associated with a steep rise in mortality and morbidity, including diabetes. There are limited data on the prevalence of CKD and the association with diabetes in outpatients with cirrhosis.

Methodology

This is a cross-sectional study of 7,440 adult liver cirrhosis patients enrolled from August 2001 to April 2010 in a medical center. Case control matching by age and sex with 1,967 pairs, and conditional logistic regression for odds of diabetes was analyzed using adjusted model.

Results

CKD was present in 46.0%, 45.7% and 45.6% of the study population using the MDRD-6, CKD-EPI and MDRD-4 estimated glomerular filtration rate (eGFR) equations, respectively. Using a conditional logistic regression model after adjusting for other risk factors, odds for diabetes increased significantly compared with non-CKD in CKD stage 3 to 5 (stage 3~5) based on MDRD-6–adjusted model, ORs were: stage 3~5, 2.34 (95% CI, 1.78-3.01); MDRD-4–adjusted model, ORs were: stage 3~5, 8.51 (95% CI, 5.63-11.4); CKD-EPI–adjusted model, ORs were: stage 3~5, 8.61 (95% CI, 5.13-13.9).

Conclusion

In cirrhosis patients, prevalence of diabetes was higher in patients with advanced stage of CKD. For patients with cirrhosis, patients with CKD stages 3~5 defined by MDRD-4, MDRD-6, and CKD-EPI eGFR equations had increased risk for diabetes. More severe cirrhosis, indicated by the Child-Turcott-Pugh classification was also accompanied by an increased risk for diabetes.

Mimicking oxygen delivery and waste removal functions of blood

In addition to immunological and wound healing cell and platelet delivery, ion stasis and nutrient supply, blood delivers oxygen to cells and tissues and removes metabolic wastes. For decades researchers have been trying to develop approaches that mimic these two immediately vital functions of blood. Oxygen is crucial for the long-term survival of tissues and cells in vertebrates. Hypoxia (oxygen deficiency) and even at times anoxia (absence of oxygen) can occur during organ preservation, organ and cell transplantation, wound healing, in tumors and engineering of tissues. Different approaches have been developed to deliver oxygen to tissues and cells, including hyperbaric oxygen therapy (HBOT), normobaric hyperoxia therapy (NBOT), using biochemical reactions and electrolysis, employing liquids with high oxygen solubility, administering hemoglobin, myoglobin and red blood cells (RBCs), introducing oxygen-generating agents, using oxygen-carrying microparticles, persufflation, and peritoneal oxygenation. Metabolic waste accumulation is another issue in biological systems when blood flow is insufficient. Metabolic wastes change the microenvironment of cells and tissues, influence the metabolic activities of cells, and ultimately cause cell death. This review examines advances in blood mimicking systems in the field of biomedical engineering in terms of oxygen delivery and metabolic waste removal.

Increased Inflammatory Response in Association with the Initiation of Hemodialysis Compared with Peritoneal Dialysis in a Prospective Study of End-Stage Kidney Disease Patients

BACKGROUND

Large epidemiological studies have demonstrated an early survival advantage with the initiation of peritoneal dialysis (PD) compared to haemodialysis (HD). Chronic inflammation may contribute to atherosclerosis and cardiovascular (CVD) mortality in end-stage kidney disease (ESKD). We hypothesize that the initiation of HD in ESKD patients is associated with a greater inflammatory response compared with PD.

AIMS

To examine the effects of initiating HD and PD upon inflammation and CVD risk markers in ESKD patients.

METHODS

We performed a pilot prospective study on 75 predialysis CKD stage-5 subjects comparing the effects of HD and PD upon high sensitivity C-reactive protein (hsCRP), interleukin(IL)-12, IL-18 and pulse wave velocity (PWV). Study visits were conducted 3 - 6 months before (baseline) and after (follow-up) initiation of dialysis RESULTS: Thirty-nine and 36 patients were initiated on HD and PD respectively. HD patients were older than PD patients (65.1 ± 2.1 vs 57.7 ± 2.7 years; p = 0.03) but had similar baseline systolic blood pressure (SBP), pulse pressure (PP), hsCRP, IL-12, IL-18, and PWV. At follow-up, HD patients had significantly increased hsCRP levels [5.2(3.7, 7.3) vs 1.7(1.0, 2.8)g/L; p < 0.001] compared to PD. Follow-up blood pressure, IL-12, IL-18, and PWV were similar between groups. A significant association remained between hsCRP and HD after adjustment for age, previous CVD, and residual urine output.

CONCLUSION

The initiation of HD was associated with significantly increased hsCRP compared to PD. Further study is required to determine the plausibility of inflammation as a potential underlying contributor to the observed early mortality difference between dialysis modalities.

Vitamin D, a modulator of musculoskeletal health in chronic kidney disease

The spectrum of activity of vitamin D goes beyond calcium and bone homeostasis, and growing evidence suggests that vitamin D contributes to maintain musculoskeletal health in healthy subjects as well as in patients with chronic kidney disease (CKD), who display the combination of bone metabolism disorder, muscle wasting, and weakness. Here, we review how vitamin D represents a pathway in which bone and muscle may interact. In vitro studies have confirmed that the vitamin D receptor is present on muscle, describing the mechanisms whereby vitamin D directly affects skeletal muscle. These include genomic and non-genomic (rapid) effects, regulating cellular differentiation and proliferation. Observational studies have shown that circulating 25-hydroxyvitamin D levels correlate with the clinical symptoms and muscle morphological changes observed in CKD patients. Vitamin D deficiency has been linked to low bone formation rate and bone mineral density, with an increased risk of skeletal fractures. The impact of low vitamin D status on skeletal muscle may also affect muscle metabolic pathways, including its sensitivity to insulin. Although some interventional studies have shown that vitamin D may improve physical performance and protect against the development of histological and radiological signs of hyperparathyroidism, evidence is still insufficient to draw definitive conclusions.

Inflammation and premature aging in advanced chronic kidney disease

Systemic inflammation in end-stage renal disease is an established risk factor for mortality and a catalyst for other complications, which are related to a premature aging phenotype, including muscle wasting, vascular calcification, and other forms of premature vascular disease, depression, osteoporosis, and frailty. Uremic inflammation is also mechanistically related to mechanisms involved in the aging process, such as telomere shortening, mitochondrial dysfunction, and altered nutrient sensing, which can have a direct effect on cellular and tissue function. In addition to uremia-specific causes, such as abnormalities in the phosphate-Klotho axis, there are remarkable similarities between the pathophysiology of uremic inflammation and so-called "inflammaging" in the general population. Potentially relevant, but still somewhat unexplored in this respect, are abnormal or misplaced protein structures, as well as abnormalities in tissue homeostasis, which evoke danger signals through damage-associated molecular patterns, as well as the senescence-associated secretory phenotype. Systemic inflammation, in combination with the loss of kidney function, can impair the resilience of the body to external and internal stressors by reduced functional and structural tissue reserves, and by impairing normal organ crosstalk, thus providing an explanation for the greatly increased risk of homeostatic breakdown in this population. In this review, the relationship between uremic inflammation and a premature aging phenotype, as well as potential causes and consequences, are discussed.

Current epigenetic aspects the clinical kidney researcher should embrace

Chronic kidney disease (CKD), affecting 10–12% of the world’s adult population, is associated with a considerably elevated risk of serious comorbidities, in particular, premature vascular disease and death. Although a wide spectrum of causative factors has been identified and/or suggested, there is still a large gap of knowledge regarding the underlying mechanisms and the complexity of the CKD phenotype. Epigenetic factors, which calibrate the genetic code, are emerging as important players in the CKD-associated pathophysiology. In this article, we review some of the current knowledge on epigenetic modifications and aspects on their role in the perturbed uraemic milieu, as well as the prospect of applying epigenotype-based diagnostics and preventive and therapeutic tools of clinical relevance to CKD patients. The practical realization of such a paradigm will require that researchers apply a holistic approach, including the full spectrum of the epigenetic landscape as well as the variability between and within tissues in the uraemic milieu.

Factors Associated with Decreased Lean Tissue Index in Patients with Chronic Kidney Disease

Muscle wasting is common and is associated with increased morbidity and mortality in patients with chronic kidney disease (CKD). However, factors associated with decreased muscle mass in CKD patients are seldom reported. We performed a cross-sectional study of 326 patients (age 65.8 ± 13.3 years) with stage 3–5 CKD who were not yet on dialysis. Muscle mass was determined using the Body Composition Monitor (BCM), a multifrequency bioimpedance spectroscopy device, and was expressed as the lean tissue index (LTI, lean tissue mass/height²). An LTI of less than 10% of the normal value (low LTI) indicates muscle wasting. Patients with low LTI (n = 40) tended to be diabetic, had significantly higher fat tissue index, urine protein creatinine ratio, and interleukin-6 and tumor necrosis factor-α levels, but had significantly lower serum albumin and hemoglobin levels compared with those with normal LTI. In multivariate linear regression analysis, age, sex, cardiovascular disease, and interleukin-6 were independently associated with LTI. Additionally, diabetes mellitus remained an independent predictor of muscle wasting according to low LTI by multivariate logistic regression analysis. We conclude that LTI has important clinical correlations. Determination of LTI may aid in clinical assessment by helping to identify muscle wasting among patients with stage 3–5 CKD.

The systemic nature of CKD

The accurate definition and staging of chronic kidney disease (CKD) is one of the major achievements of modern nephrology. Intensive research is now being undertaken to unravel the risk factors and pathophysiologic underpinnings of this disease. In particular, the relationships between the kidney and other organs have been comprehensively investigated in experimental and clinical studies in the last two decades. Owing to technological and analytical limitations, these links have been studied with a reductionist approach focusing on two organs at a time, such as the heart and the kidney or the bone and the kidney. Here, we discuss studies that highlight the complex and systemic nature of CKD. Energy balance, innate immunity and neuroendocrine signalling are highly integrated biological phenomena. The diseased kidney disrupts such integration and generates a high-risk phenotype with a clinical profile encompassing inflammation, protein-energy wasting, altered function of the autonomic and central nervous systems and cardiopulmonary, vascular and bone diseases. A systems biology approach to CKD using omics techniques will hopefully enable in-depth study of the pathophysiology of this systemic disease, and has the potential to unravel critical pathways that can be targeted for CKD prevention and therapy.

Is Fibroblast growth factor 23 the leading cause of increased mortality among chronic kidney disease patients? A narrative review

The death rate among chronic kidney disease patients is the highest compared to other chronic diseases. 60% of these fatalities are cardiovascular. Cardiovascular calcifications and chronic inflammation affect almost all chronic kidney disease patients and are associated with cardiovascular mortality. Fibroblast growth factor 23 is associated with vascular calcification. Systemic inflammation in chronic kidney disease patients is multifactorial. The role of systemic inflammation in the pathogenesis of vascular calcification was recently reappraised. Fibroblast growth factor 23 was accused as a direct stimulus of left ventricular hypertrophy, uremic inflammation, and impaired neutrophil function. This review will discuss the underlying mechanisms that underlie the link between Fibroblast growth factor 23 and increased mortality encountered among chronic kidney disease patients.

The Strategy to Prevent and Regress the Vascular Calcification in Dialysis Patients

The high prevalence of arterial calcification in end-stage renal disease (ESRD) is far beyond the explanation by common cardiovascular risk factors such as aging, diabetes, hypertension, and dyslipidemia. The finding relies on the fact that vascular and valvular calcifications are predictors of cardiovascular diseases and mortality in persons with chronic renal failure. In addition to traditional cardiovascular risk factors such as diabetes mellitus and blood pressure control, other ESRD-related risks such as phosphate retention, excess calcium, and prolonged dialysis time also contribute to the development of vascular calcification. The strategies are to reverse "calcium paradox" and lower vascular calcification by decreasing procalcific factors including minimization of inflammation (through adequate dialysis and by avoiding malnutrition, intravenous labile iron, and positive calcium and phosphate balance), correction of high and low bone turnover, and restoration of anticalcification factor balance such as correction of vitamin D and K deficiency; parathyroid intervention is reserved for severe hyperparathyroidism. The role of bone antiresorption therapy such as bisphosphonates and denosumab in vascular calcification in high-bone-turnover disease remains unclear. The limited data on sodium thiosulfate are promising. However, if calcification is to be targeted, ensure that bone health is not compromised by the treatments.

Vascular calcification: When should we interfere in chronic kidney disease patients and how?

Chronic kidney disease (CKD) patients are endangered with the highest mortality rate compared to other chronic diseases. Cardiovascular events account for up to 60% of the fatalities. Cardiovascular calcifications affect most of the CKD patients. Most of this calcification is related to disturbed renal phosphate handling. Fibroblast growth factor 23 and klotho deficiency were incriminated in the pathogenesis of vascular calcification through different mechanisms including their effects on endothelium and arterial wall smooth muscle cells. In addition, deficient klotho gene expression, a constant feature of CKD, promotes vascular pathology and shares in progression of the CKD. The role of gut in the etio-pathogenesis of systemic inflammation and vascular calcification is a newly discovered mechanism. This review will cover the medical history, prevalence, pathogenesis, clinical relevance, different tools used to diagnose, the ideal timing to prevent or to withhold the progression of vascular calcification and the different medications and medical procedures that can help to prolong the survival of CKD patients.

A Prospective Multicenter Randomized Controlled Study on Interleukin-6 Removal and Induction by a new Hemodialyzer With Improved Biocompatibility in Hemodialysis Patients: A Pilot Study

We compared interleukin-6 (IL-6) removal and induction between conventional polysulfone (Con) and TORAYLIGHT NV (NV) dialyzers in hemodialysis patients. Twenty patients on Con with high IL-6 concentrations (2.7-8.5 pg/mL) were randomized to Con or NV group. Dialyzer performance was determined in NV group while patients were on Con and after being switched onto NV. Erythropoiesis-stimulating agent (ESA) response index (ERI) was assessed every 4 months for one year. IL-6 clearance was comparable between Con and NV. IL-6 removal rates were comparable for the first 1 h, but were higher with NV for the entire session (P = 0.03). Before-to-during-dialysis IL-6 concentration ratios were lower with NV on the venous side after the session (P = 0.03). During the one-year study, hemoglobin was lower in Con group than in NV group at month 8 (P = 0.046). ERI decreased in NV and increased in Con group, with a significant difference between the groups (P = 0.002). NV and Con are comparable in removing IL-6 and both induce IL-6. However, the data suggest that NV induces less IL-6, which may reduce the risk of ESA hyporesponsiveness.

Long-term effects of angiotensin II blockade with irbesartan on inflammatory markers in hemodialysis patients: A randomized double blind placebo controlled trial (SAFIR study)

INTRODUCTION

Low-grade chronic inflammation is common in hemodialysis (HD) patients. Previous studies suggest an anti-inflammatory effect of angiotensin II receptor blocker (ARB) treatment. The aim of this study was to compare the effect of ARB vs. placebo on plasma concentrations of inflammatory markers in HD patients.

METHODS

Adult HD patients were randomized for double-blind treatment with the ARB irbesartan 150-300 mg/day or placebo. At baseline, 1 week, 3, 6, 9, and 12 months plasma high sensitivity C-reactive protein (hsCRP), interleukin (IL)-1β, IL-6, IL-8, IL-18, and transforming growth factor-β (TGF-β) were measured using Luminex and enzyme-linked immunosorbent assay (ELISA) technology.

FINDINGS

Eighty-two patients were randomized (placebo/ARB: 41/41). The groups did not differ in initial levels of any of the inflammatory markers (placebo/ARB median(range)): hsCRP 3.3(0.2-23.4)/2.7(0.2-29.6) μg/mL; IL-1β 1.1(0.0-45.9)/1.1(0.0-7.2) pg/mL; IL-6 10(1-90)/12(1-84) pg/mL; IL-8 31(9-134)/34(5-192) pg/mL; IL-18 364(188-1343)/377(213-832) pg/mL; TGF-β 3.2(0.8-13.9)/3.6(1.3-3.8) ng/mL. Overall, there was no significant difference in hsCRP, IL-6, IL-8, and TGF-β between placebo and ARB-treated patients during the study period, and hsCRP, IL-6, IL-8, and TGF-β were relatively stable during the study period (P ≥ 0.18 in all tests for parallel curves, equal levels, and constant levels). The IL-1β level was slightly different in the two groups over time, but not significantly (P = 0.09 in test for parallel curves) and it was also relatively stable during the study period (P ≥ 0.49 in tests for equal levels and constant level). IL-18 was the only inflammatory marker which was not constant during the study period (P = 0.001 in test for constant level), but there was no significant difference between placebo and ARB-treated (P ≥ 0.51 in tests for parallel curves and equal levels).

DISCUSSION

Inflammatory biomarkers were neither acutely, nor in the long-term significantly affected by the ARB irbesartan. Our findings suggest that ARB treatment in HD patients does not offer protective anti-inflammatory effects.

Is there a connection between inflammation, telomerase activity and the transcriptional status of telomerase reverse transcriptase in renal failure?

Telomerase is involved in the elongation of telomeres. It remains active in very few types of cell in mature organisms. One such cell type is the lymphocytes. In this study, we investigated the activity and expression of telomerase in lymphocytes from renal failure patients and compared it to that for normal controls. Inflammation status was determined at the same time. The enzyme activity was measured using PCR-ELISA with peripheral blood mononuclear cells (PBMCs) from three groups: 53 healthy individuals, 50 patients with chronic kidney disease (CKD) and 50 dialysis patients. In the same cell populations, the expression of the reverse transcriptase of the human telomerase gene (hTERT) was measured via real-time PCR. The inflammationstatus of these individuals was determined by calculating the interleukin 6 (IL-6), IL-10, C-reactive protein (CRP) and tumor necrosis factor alpha (TNF-a) serum concentrations via ELISA. The lowest levels of telomerase activity were detected in CKD, and this group had the highest IL-6 and CRP values and the lowest hTERT expression. The dialysis group showed significant differences in comparison to the normal subjects and to the CKD patients. Further studies are warranted in order to explore the way inflammation influences telomerase activity and hTERT expression.

Stop chronic kidney disease progression: Time is approaching

Progression of chronic kidney disease (CKD) is inevitable. However, the last decade has witnessed tremendous achievements in this field. Today we are optimistic; the dream of withholding this progression is about to be realistic. The recent discoveries in the field of CKD management involved most of the individual diseases leading the patients to end-stage renal disease. Most of these advances involved patients suffering diabetic kidney disease, chronic glomerulonephritis, polycystic kidney disease, renal amyloidosis and chronic tubulointerstitial disease. The chronic systemic inflammatory status and increased oxidative stress were also investigated. This inflammatory status influences the anti-senescence Klotho gene expression. The role of Klotho in CKD progression together with its therapeutic value are explored. The role of gut as a major source of inflammation, the pathogenesis of intestinal mucosal barrier damage, the role of intestinal alkaline phosphatase and the dietary and therapeutic implications add a novel therapeutic tool to delay CKD progression.