Hemodialysis central venous catheters as a source of inflammation and its implications

Hypoglycemia and Mortality Risk in Incident Hemodialysis Patients

OBJECTIVE

Hypoglycemia is a frequent occurrence in chronic kidney disease patients due to alterations in glucose and insulin metabolism. However, there are sparse data examining the predictors and clinical implications of hypoglycemia including mortality risk among incident hemodialysis patients.

DESIGN AND METHODS

Among 58,304 incident hemodialysis patients receiving care from a large national dialysis organization over 2007-2011, we examined clinical characteristics associated with risk of hypoglycemia, defined as a blood glucose concentration <70 mg/dL, in the first year of dialysis using expanded case-mix + laboratory logistic regression models. We then examined the association between hypoglycemia during the first year of dialysis with all-cause mortality using expanded case-mix + laboratory Cox models.

RESULTS

In the first year of dialysis, hypoglycemia was observed among 16.8% of diabetic and 6.9% of nondiabetic incident hemodialysis patients. In adjusted logistic regression models, clinical characteristics associated with hypoglycemia included younger age, female sex, African-American race, presence of a central venous catheter, lower residual renal function, and longer dialysis session length. In the overall cohort, patients who experienced hypoglycemia had a higher risk of all-cause mortality risk (reference: absence of hypoglycemia): adjusted hazard ratio (95% confidence interval) 1.08 (1.04, 1.13). In stratified analyses, hypoglycemia was also associated with higher mortality risk in the diabetic and nondiabetic subgroups: adjusted hazard ratios (95% confidence interval's) 1.08 (1.04-1.13), and 1.17 (0.94-1.45), respectively.

CONCLUSIONS

Hypoglycemia was a frequent occurrence among both diabetic and nondiabetic hemodialysis patients and was associated with a higher mortality risk. Further studies are needed to identify approaches that reduce hypoglycemia risk in the hemodialysis population.

Immunological features of ESRD patients undergoing hemodialysis of various ages

AIMS

To investigate the immunological characteristics of hemodialysis (HD) patients with end-stage renal disease (ESRD) of various ages, and the impact of age-related immune alterations on these patients, with a focus on peripheral T cells.

METHODS

From September 2016 to September 2019, HD patients were enrolled and followed prospectively for 3 years. Patients were divided into three groups based on their ages: < 45, 45 to 64, and ≥ 65. The distribution of T cell subsets in different age groups was investigated and compared. The effects of altered T cell subsets on overall survival were also investigated.

RESULTS

A total of 371 HD patients were enrolled. The reduced number of naive CD8+ T cells (P < 0.001) and increased number of EMRA CD8+ T cells (P = 0.024) were independently associated with the advanced age among all T cell subsets studied. Patient survival may be affected by numerical changes in naive CD8+ T cells. However, when HD patients were < 45 or ≥ 65 years, the reduction had no significant impact on survival. Only in HD patients aged 45 to 64 years, the number of naïve CD8+ T cells found to be insufficient but not deficient, identified as an independent predictor of poor survival.

CONCLUSIONS

The most significant age-related immune change in HD patients was a decrease in peripheral naive CD8+ T cells, which was an independent predictor of 3-year overall survival in HD patients aged 45 ~ 64 years.

Differences in Malnutrition Inflammation Score of Hemodialysis Patients Associated With Hemodialysis Factors. A Spanish Multicenter Epidemiologic Study

OBJECTIVES

The aims of this study are to analyze the prevalence of malnutrition in hemodialysis (HD) patients in Spain, and to assess the association of malnutrition in these patients with sociodemographic characteristics, comorbidity, and parameters related to HD.

DESIGN AND METHODS

A multicenter, retrospective, cross-sectional study in HD patients from centers all over Spain was conducted. Nutritional status of patients was assessed using Malnutrition Inflammation Score (MIS), and was stratified according to MIS values into 5 categories: ≤2, normal nutrition; >2 to ≤5, mild malnutrition or risk of malnutrition; >5 to ≤7, moderate malnutrition; >7 to ≤10, severe malnutrition, and >10, extreme malnutrition.

RESULTS

A total of 52 Spanish HD Units participated in the study enrolling 2,748 patients. Mean age of patients was 68.20 ± 14.24 years, 1,811 (65.9%) were men. Mean time on HD was 55.63 ± 63.25 months. Using an MIS cut-off point of 2 for malnutrition, 89% of patients were malnourished (MIS > 2). However, with a cut-off point of 5, more commonly described in the literature, the percentage of patients with malnutrition was reduced to 51.7%. Using this cut-off, we observed significant differences between patients with malnutrition and normo-nourished patients in biochemical parameters, age, Charlson Index, HD residual renal function, scheme, and vascular access (permanent catheter vs arteriovenous fistula). A multivariate regression analysis showed that age, sex, HD scheme, vascular access, residual renal function, and comorbidity index were predictive factors for malnutrition. We found that a high percentage of HD patients with malnutrition did not receive oral supplementation.

CONCLUSIONS

The prevalence of malnutrition in HD patients in Spain, assessed using the MIS scale, was high. Higher malnutrition was associated with the use of catheter versus fistula, and standard HD versus online hemodiafiltration, and with the absence of residual renal function, older age, greater comorbidity, and male sex. Malnourished patients had a low rate of oral supplementation.

Systemic Profile of Cytokines in Arteriovenous Fistula Patients and Their Associations with Maturation Failure

Background

Systemic cytokines are elevated in patients with chronic kidney disease (CKD) and on hemodialysis compared with the general population. However, whether cytokine levels interfere with vascular remodeling, increasing the risk of arteriovenous fistula (AVF) failure, remains unknown.

Methods

This is a case-control study of 64 patients who underwent surgery for AVF creation (32 with AVF maturation failure and 32 matching controls with successful maturation). A total of 74 cytokines, including chemokines, interferons, interleukins, and growth factors, were measured in preoperative plasma samples using multiplex assays. Sixty-two patients were included in the statistical analyses. Associations with AVF failure were assessed using paired comparisons and conditional logistic regressions accounting for paired strata.

Results

Seven cytokines were significantly higher in patients with AVF maturation failure than in matching controls (G-CSF, IL-6, MDC, RANTES, SDF-1α/β, TGFα, and TPO). Of these, G-CSF (odds ratio [OR]=1.71; 95% confidence interval [95% CI], 1.05 to 2.79 per 10 pg/ml), MDC (OR=1.60, 95% CI, 1.08 to 2.38 per 100 pg/ml), RANTES (OR=1.55, 95% CI, 1.10 to 2.17 per 100 pg/ml), SDF-1α/β (OR=1.18, 95% CI, 1.04 to 1.33 per 1000 pg/ml), and TGFα (OR=1.39, 95% CI 1.003, 1.92 per 1 pg/ml) showed an incremental association by logistic regression.

Conclusions

This study identified a profile of plasma cytokines associated with adverse maturation outcomes in AVFs. These findings may open the doors for future therapeutics and markers for risk stratification.

Nomogram for predicting 1-, 5-, and 10-year survival in hemodialysis (HD) patients: a single center retrospective study

Objectives

Risk of death is high for hemodialysis (HD) patients but it varies considerably among individuals. There is few clinical tool to predict long-term survival rates for HD patients yet. The aim of this study was to develop and validate a easy-to-use nomogram for prediction of 1-, 5-, and 10-year survival among HD patients.

Methods

This study retrospectively enrolled 643 adult HD patients who was randomly assigned to two cohorts: the training cohort (n = 438) and validation cohort (n = 205), univariate survival analyses were performed using Kaplan–Meier’s curve with log-rank test and multivariate Cox regression analyses were performed to identify predictive factors, and a easy-to-use nomogram was established. The performance was assessed using the area under the curve (AUC), calibration plots, and decision curve analysis.

Results

The score included seven commonly available predictors: age, diabetes, use of arteriovenous fistula (AVF), history of emergency temporary dialysis catheter placement, cardiovascular disease (CVD), hemoglobin (Hgl), and no caregiver. The score revealed good discrimination in the training and validation cohort (AUC 0.779 and 0.758, respectively) and the calibration plots showed well calibration, indicating suitable performance of the nomogram model. Decision curve analysis showed that the nomogram added more net benefit compared with the treat-all strategy or treat-none strategy with a threshold probability of 10% or greater.

Conclusions

This easy-to-use nomogram can accurately predict 1-, 5-, and 10-year survival for HD patients, which could be used in clinical decision-making and clinical care.

Abbreviations:

Association between Variations in Body Mass Index and Cognitive Function in Older Korean Adults

Background

Although several studies have assessed obesity and cognitive impairment, most of these studies focus on body mass index (BMI) and cognitive impairment. Therefore to better understand the importance of weight maintenance with aging, this study investigated the relationship between variations in weight and cognitive impairment using the Korean version of the Mini-Mental State Examination (K-MMSE) in individuals aged 45 years or older in Korea.

Methods

Data on 3,477 adults with normal cognitive function (K-MMSE ≥24) at baseline were acquired from the Korean Longitudinal Study of Aging (KLoSA) 2006-2016. The association between weight variability and risk of cognitive impairment was assessed using multiple logistic regression models. We also assessed weight variability and change in cognitive function over the 6-year follow-up using multiple linear regression.

Results

Overall, higher variations in BMI were associated with cognitive impairment. Patients in the quintile with the highest variation (Q5) in BMI (mean of BMI changes, 2.69) showed the greatest degree of cognitive impairments (adjusted odds ratio, 1.52; 95% confidence interval [CI], 1.08-2.14; P for trend=0.016). Furthermore, a higher frequency in the number of times (3 times) the patient’s body weight changed was associated with a lower cognitive function (adjusted odds ratio, 3.42; 95% CI, 1.67-7.03; P for trend<0.001).

Conclusion

In this nationally representative study, weight variability was associated with a higher risk of cognitive decline during mid- and late-life stages.

Arnold-Chiari Malformation and Scoliosis: A Chronic Lung Collapse Mimicking Sepsis

Scoliosis is a deformity of the spine caused by excessive lateral curvature. Compared to other variants, neuromuscular scoliosis is more likely to progress, altering the body's normal architecture in a relatively short period of time. Furthermore, patients with Arnold-Chiari malformation or Chiari malformation (CM) type 2 have intrinsic neurological complications that might entangle the initial clinical assessment. A 24-year-old woman with a history of scoliosis and CM type 2 status post-tracheostomy was admitted from a skilled nursing facility after a one-day history of low blood pressure, leukocytosis, and an outpatient chest X-ray suspicious for pneumonia. Physical examination was remarkable for hypotension and decreased breath sounds at the left pulmonary base. A tracheostomy tube and central venous catheter were noticed. Initial laboratory results revealed leukocytosis with borderline bandemia and a chest X-ray with a left lower lung consolidation. She was treated as a case of sepsis, for which broad-spectrum antibiotics were immediately started. However, upon review of charts, the patient's objective findings were similar to a previous admission. Chest computed tomography scan revealed atelectasis in the left lower lung with no signs of consolidation, effusions, or abscesses. After extensive workup, no identifiable cause was found to suggest an acute process. Antibiotic therapy was halted and the patient was discharged to her nursing home. This case presents a patient with CM type 2 and scoliosis complicated by chronic and worsening atelectasis. Accurate initial assessment and communication between providers are paramount to avoid overtreatment.

The combination of malnutrition-inflammation and functional status limitations is associated with mortality in hemodialysis patients

The identification of malnutrition-inflammation-complex (MIC) and functional status (FS) is key to improving patient experience on hemodialysis (HD). We investigate the association of MIC and FS combinations with mortality in HD patients. We analyzed data from 5630 HD patients from 9 countries in DOPPS phases 4–5 (2009–2015) with a median follow-up of 23 [IQR 11, 31] months. MIC was defined as serum albumin < 3.8 g/dL and serum C-reactive protein > 3 mg/L in Japan and > 10 mg/L elsewhere. FS score was defined as the sum of scores from the Katz Index of Independence in Activities of Daily Living and the Lawton-Brody Instrumental Activities of Daily Living Scale. We investigated the association between combinations of MIC (+/−) and FS (low [< 11]/high [≥ 11]) with death. Compared to the reference group (MIC−/high FS), the adjusted hazard ratios [HR (95% CI)] for all-cause mortality were 1.82 (1.49, 2.21) for MIC−/low FS, 1.57 (1.30, 1.89) for MIC+/high FS, and 3.44 (2.80, 4.23) for MIC+/low FS groups. Similar associations were observed with CVD-related and infection-related mortality. The combination of MIC and low FS is a strong predictor of mortality in HD patients. Identification of MIC and poor FS may direct interventions to lessen adverse clinical outcomes in the HD setting.

Lipoteichoic Acid as a Potential Noninvasive Biomarker of Biofilm in Dialysis Access

Tunneled central venous catheters (TCVCs) are colonized by Gram-positive organisms and form biofilm. Lipoteichoic acid (LTA) is a Gram-positive cell wall component that can be measured in serum. The purpose of this pilot study was to characterize LTA concentrations in hemodialysis (HD) patients with TCVCs compared to other access types and to evaluate biofilm morphology and microbiology in TCVCs removed by clinical decision. The study enrolled patients with TCVCs (18), grafts (19), and fistulas (18). Blood samples were collected before HD, at 30 minutes, 2 hours, and end of HD. Catheters removed by clinical decision were evaluated by scanning electron microscopy (SEM) for biofilm morphology, and portions of the catheter were cultured. LTA was detectable in all samples and concentrations increased significantly in all access types during HD (p < 0.05 for all comparisons). Patients with TCVCs that had a >30% increase in LTA concentration from baseline also had the greatest rate of increase (slope) compared to grafts and fistulas (p = 0.03 and p = 0.04, respectively). Catheters removed by clinical decision (n = 7) and examined by SEM had deposition of fibrin. Cultures revealed polymicrobial colonization. TCVCs had the highest rate of increase of LTA during HD. Further studies to determine the source of LTA in patients with AVG and AVF are warranted.

Urgent-start peritoneal dialysis results in fewer procedures than hemodialysis

BACKGROUND

Peritoneal dialysis (PD) is an underutilized modality for hospitalized patients with an urgent need to start renal replacement therapy in the USA. Most patients begin hemodialysis (HD) with a tunneled central venous catheter (CVC).

METHODS

We examined the long-term burden of dialysis modality-related access procedures with urgent-start PD and urgent-start HD in a retrospective cohort of 73 adults. The number of access-related (mechanical and infection-related) procedures for each modality was compared in the first 30 days and cumulatively through the duration of follow-up.

RESULTS

Fifty patients underwent CVC placement for HD and 23 patients underwent PD catheter placement for urgent-start dialysis. Patients were followed on average >1 year. The PD group was significantly younger, with less diabetes, with a higher pre-dialysis serum creatinine and more likely to have a planned dialysis access. The mean number of access-related procedures per patient in the two groups was not different at 30 days; however, when compared over the duration of follow-up, the number of access-related procedures was significantly higher in the HD group compared with the PD group (4.6 ± 3.9 versus 0.61 ± 0.84, P < 0.0001). This difference persisted when standardized to procedures per patient-month (0.37 ± 0.57 versus 0.081 ± 0.18, P = 0.019). Infection-related procedures were similar between groups. Findings were the same even after case-matching was performed for age and diabetes mellitus with 18 patients in each group.

CONCLUSIONS

Urgent-start PD results in fewer invasive access procedures compared with urgent-start HD long term, and should be considered for urgent-start dialysis.

Quantification of Lipoteichoic Acid in Hemodialysis Patients With Central Venous Catheters

Hemodialysis patients with central venous catheters (CVCs) have chronic systemic inflammation, the source of which may be related to intraluminal bacterial biofilm. There is currently no non-invasive method to adequately evaluate intraluminal biofilm. Lipoteichoic acid (LTA) is a Gram-positive bacterial cell wall component that is spontaneously shed. The purpose of this study was to determine whether LTA could be quantified in biological samples and to evaluate potential relationships to markers of inflammation. Heparin-locked catheter aspirate was drawn from both the arterial and venous ports of each CVC prior to dialysis initiation. Venous blood from the dialysis circuit was collected 30 min after dialysis initiation. LTA was quantified in aspirate and plasma. Key markers of inflammation (interleukin-6, and hepcidin) and endothelial dysfunction (soluble vascular endothelial cadherin) were also determined in plasma samples. Catheter aspirate and systemic blood samples were obtained from 40 hemodialysis patients. The median (range) duration of catheter use was 130 (20–1635) days. Unexpectedly, median (range) plasma LTA concentrations (ng/mL) were significantly higher than catheter aspirate LTA concentrations [3.93 (0.25–15) vs. 2.38 (0.1–8.1), respectively, p = 0.01] in the majority (70%) of patients. Area under the receiver operator characteristic (ROC) curve showed good potential prognostic value of catheter aspirate LTA predicting systemic LTA concentrations with an area under the curve of 0.815 (95% CI, 0.68–0.95). A significant correlation was found between LTA and serum ferritin (r = 0.32, p = 0.04), however, there were no significant correlations between LTA and the other inflammation biomarkers assessed. LTA is quantifiable in aspirate and plasma of hemodialysis patients with CVCs and warrants further investigation to determine potential clinical application to intraluminal biofilm evaluation.

The anaemia control model: Does it help nephrologists in therapeutic decision-making in the management of anaemia?

INTRODUCTION

Anaemia is common in haemodialysis patients and treating it with erythropoiesis-stimulating agents (ESAs) is complex due to many factors.

OBJECTIVES

To assess the usefulness of the Anaemia Control Model (ACM) in the treatment of anaemia in haemodialysis.

METHODS

ACM is a software that predicts the optimal dose of darbepoetin and iron sucrose to achieve target haemoglobin (Hb) and ferritin levels, and makes prescription suggestions. Study conducted in dialysis clinics lasting 18months with two intervention phases (IPs) with ACM (IP1, n:213; IP2, n:218) separated by a control phase (CP, n:219). The primary outcome was the percentage of Hb in range and the median dose of ESAs, and the secondary outcomes were transfusion, hospitalisation and cardiovascular events. Clinical and patient analyses were performed. Hb variability was assessed by the standard deviation (SD) of the Hb. We also analysed the patients with most of the suggestions confirmed (ACM compliant group).

RESULTS

ACM increased the percentage of Hb in range: 80.9% in IP2, compared with 72.7% in the CP and reduced the intake of darbepoetin (IP1: 20 [70]; CP 30 [80] μg P=0.032) with less Hb fluctuation (0.91±0.49 in the CP to 0.82±0.37g/dl in IP2, P<0.05), improving in the ACM compliant group. The secondary outcomes decreased with the use of ACM.

CONCLUSIONS

ACM helps to obtain better anaemia results in haemodialysis patients, minimising the risks of treatment with ESAs and reducing costs.

High soluble CD30 levels and associated anti-HLA antibodies in patients with failed renal allografts

INTRODUCTION

Serum soluble CD30 (sCD30), a 120-kD glycoprotein that belongs to the tumor necrosis factor receptor family, has been suggested as a marker of rejection in kidney transplant patients. The aim of this study was to evaluate the relationship between sCD30 levels and anti-HLA antibodies, and to compare sCD30 levels in patients undergoing hemodialysis (HD) with and without failed renal allografts and transplant recipients with functioning grafts.

METHODS

100 patients undergoing HD with failed grafts (group 1), 100 patients undergoing HD who had never undergone transplantation (group 2), and 100 kidney transplant recipients (group 3) were included in this study. Associations of serum sCD30 levels and anti-HLA antibody status were analyzed in these groups.

RESULTS

The sCD30 levels of group 1 and group 2 (154 ± 71 U/mL and 103 ± 55 U/mL, respectively) were significantly higher than those of the transplant recipients (group 3) (39 ± 21 U/mL) (p&lt;0.001 and p&lt;0.001). The serum sCD30 levels in group 1 (154 ± 71 U/mL) were also significantly higher than group 2 (103 ± 55 U/mL) (p&lt;0.001). Anti-HLA antibodies were detected in 81 (81%) and 5 (5%) of patients in groups 1 and 2, respectively (p&lt;0.001). When multiple regression analysis was performed to predict sCD30 levels, the independent variables in group 1 were the presence of class I anti-HLA antibodies (β = 0.295; p = 0.003) and age (β = -0.272; p = 0.005), and serum creatinine (β = 0.218; p = 0.027) and presence of class II anti-HLA antibodies (standardized β = 0.194; p = 0.046) in group 3.

CONCLUSIONS

Higher sCD30 levels and anti-HLA antibodies in patients undergoing HD with failed renal allografts may be related to higher inflammatory status in these patients.

Duplex Ultrasound for the Prediction of Vascular Events Associated with Arteriovenous Fistulas in Hemodialysis Patients

Objective

To determine if duplex ultrasound (US) for arteriovenous fistulas (AVFs) can predict vascular events (VEs; thrombosis and stenosis).

Methods

Duplex US was performed for vascular access evaluation in 2557 maintenance hemodialysis (HD) patients between October 1, 2013 and March 31, 2016. Of these patients, 2184 patients were finally included in this study. AVF dysfunction was assessed using the brachial artery blood flow volume (Qa; mL/min), arterial blood flow resistance index (RI), and residual diameter of the fistula vein (RD; mm). Proximal, midpoint, and distal aspects of the fistulas were measured. The baseline measurements were the US assessments, and the endpoint was VEs requiring vascular access intervention therapy or vascular surgery. Associations of US findings and VEs were assessed with receiver operating characteristic curve analysis, log-rank analysis, and multivariate Cox hazard models.

Results

The mean Qa was 772.8 ± 441.4 mL/min; RI, 0.56 ± 0.1; and RD, 2.37 ± 1.0 mm. The optimal Qa cut-off point was calculated as 581.5 mL/min, RI cut-off as 0.56, and RD cut-off as 1.85 mm. VEs were more frequent in patients with a Qa <581.5 mL/min than in those with a Qa >581.5 mL/min (p<0.001). In multivariate analysis, Qa, ferritin, transferrin saturation, and warfarin use were significantly associated with VEs.

Conclusions

US evaluation of AVFs in HD patients is a simple method to predict the risks of thrombosis and fistula dysfunction. Qa, ferritin, transferrin saturation, and warfarin use might be associated with VEs.

Association of Vascular Access Type with Mortality, Hospitalization, and Transfer to In-Center Hemodialysis in Patients Undergoing Home Hemodialysis

BACKGROUND AND OBJECTIVES

In individuals undergoing in-center hemodialysis (HD), use of central venous catheters (CVCs) is associated with worse clinical outcomes compared with use of arteriovenous access. However, it is unclear whether a similar difference in risk by vascular access type is present in patients undergoing home HD.

DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS

Our study examined the associations of vascular access type with all-cause mortality, hospitalization, and transfer to in-center HD in patients who initiated home HD from 2007 to 2011 in 464 facilities in 43 states in the United States. Patients were followed through December 31, 2011. Data were analyzed using competing risks hazards regression, with vascular access type at the start of home HD as the primary exposure in a propensity score-matched cohort (1052 patients; 526 with CVC and 526 with arteriovenous access).

RESULTS

Over a median follow-up of 312 days, 110 patients died, 604 had at least one hospitalization, and 202 transferred to in-center hemodialysis. Compared with arteriovenous access use, CVC use was associated with higher risk for mortality (hazard ratio, 1.73; 95% confidence interval, 1.18 to 2.54) and hospitalization (hazard ratio, 1.19; 95% confidence interval, 1.02 to 1.39). CVC use was not associated with increased risk for transfer to in-center HD. The results of analyses in the entire unmatched cohort (2481 patients), with vascular access type modeled as a baseline exposure at start of home HD or a time-varying exposure, were similar. Analyses among a propensity score-matched cohort of patients undergoing in-center HD also showed similar risks for death and hospitalization with use of CVCs.

CONCLUSIONS

In a large cohort of patients on home HD, CVC use was associated with higher risk for mortality and hospitalization. Additional studies are needed to identify interventions which may reduce risk associated with use of CVCs among patients undergoing home HD.

Starting Hemodialysis with Catheter and Mortality Risk: Persistent Association in a Competing Risk Analysis

Purpose

The vascular access (VA) used at hemodialysis (HD) inception is involved in the mortality risk. We analyzed the survival of incident patients over time according to the initial VA and the VA profile of patients who died during the first year of follow-up.

Methods

Data of VA were obtained from 9956 incident HD patients from the Catalan Registry.

Results

Over 12 years, 47.9% of patients initiated HD with a fístula, 1.2% with a graft, 15.9% with a tunneled catheter and 35% with an untunneled catheter. Regarding fistula use, the hazard ratio of death for all-causes over time when applying a multivariate competing risk model was 1.55 [95% confidence interval (CI): 1.42-1.69] and 1.43 (95% CI: 1.33-1.54) for patients with tunneled and untunneled catheter, respectively. During the first year of follow-up, the crude all-cause mortality rate (deaths/100 patient-years) was higher during the early (first 120 days) compared to the late (121-365 days) period: 18.3 (95% CI: 16.8-19.8) versus 15.4 (95% CI: 14.5-16.5). Regarding fistula use, for patients using untunneled and tunneled catheter, the odds ratio of death in the early period for all-causes was 3.66 (95% CI: 2.80-4.81) and 2.97 (95% CI: 2.17-4.06), for cardiovascular causes it was 2.76 (95% CI: 1.90-4.01) and 1.84 (95% CI: 1.17-2.89) and for infection-related causes it was 6.62 (95% CI: 3.11-14.05) and 4.58 (95% CI: 2.00-10.52), respectively.

Conclusions

Half of all incident patients in Catalonia are exposed to excessive mortality risk related to catheter and this scenario can be improved by early fistula placement.

Prevalence and management of anemia in hemodialysis patients in a Brazilian population of predominantly African descent

BACKGROUND/OBJECTIVE

Findings from the international DOPPS indicated a rise in hemoglobin levels for patients on maintenance hemodialysis (MHD) for more than 180 days across many countries with more than 60% with hemoglobin ≥11 g/dl. However, the situation of anemia control for a large contingent of the hemodialysis population remains unknown. Studies in the United States indicate that hemoglobin level is lower for African Americans on MHD, but studies in other populations of African descent are lacking. We investigated the prevalence of, and associated factors for, hemoglobin <11 g/dl in MHD patients from the Brazilian city with the largest proportion of African descendants outside Africa.

METHODS

Cross-sectional study of 1,263 MHD patients enrolled in the Prospective Study of the Prognosis of Chronic Hemodialysis Patients (PROHEMO) in Salvador, Brazil 2005-2009.

RESULTS

88.0% black or mixed race; age 49.0 ± 14.7 years; 96.6% receiving erythropoietin, median = 6,000 units/week. In patients on MHD for more than 180 days, 67.4% had hemoglobin <11 g/dl. Factors associated with hemoglobin<11 g/dl were MHD by catheter (odds ratio (OR) = 3.03, 95% confidence interval (CI) = 1.43-6.42), hospitalization in prior 3 months (OR = 2.14, 95% CI = 1.20-3.83), transferrin saturation <20% (OR = 1.49, 95% CI = 1.05-2.12) and higher malnutrition-inflammation score (OR = 1.58 per each log-transformed unit, 95% CI = 1.14-2.19).

CONCLUSIONS

The results suggest that iron deficiency, insufficient erythropoietin dose, catheter use, malnutrition-inflammation, and problems associated with hospitalization are explanations for the high prevalence of hemoglobin below the guideline target in MHD patients from a large African descent Brazilian population. These results have implications for understanding the lower hemoglobin concentration in MHD populations of African descent.

Alloantigen-stimulated induction and release of CD30 in patients with end-stage renal failure

High serum levels of soluble CD30 (sCD30) are associated with poor renal allograft survival, and regulatory T cells (Tregs) influence allograft survival depending on CD30 signaling. However, how sCD30 modulates alloimmune responses remains poorly understood. We measured the level of Tregs and sCD30 in patients with end-stage renal failure (ESRF) and analyzed whether allo- or polyclonal stimulation of the patients' T cells results in the expression and release of CD30. ESRF patients showed increased serum sCD30 levels and lower percentages of circulating Tregs as compared to healthy controls (HC) (p<0.001 and 0.024). Polyclonal and allogeneic stimulation resulted in higher expression of CD30, and after polyclonal stimulation, ESRF patients showed higher percentages of CD30-expressing T cells than HC (p<0.001). Compared to autologous stimulation, allogeneic stimulation induced significantly higher expression of CD30 on T cells of ESRF patients only. After polyclonal as well as allogeneic stimulation, an increased sCD30 content was found in culture supernatants of both ESRF patients and HC (p<0.001). Together with decreased Tregs, high serum sCD30 and increased induction of CD30 on T cells after polyclonal stimulation may explain exacerbated alloimmune responses and poor allograft survival in ESRF patients in whom immunosuppression is not able to control the alloimmune response.

Evaluation of the impact of a new synthetic vitamin E-bonded membrane on anemia and rHuEPO requirement in ESRD patients with central venous catheters: a pilot study

In the last years, the number of hemodialysis (HD) patients with erythropoietin (rHuEPO) resistance is increasing. Probably, central venous catheters (CVCs) contribute to this resistance by inducing inflammation and oxidative stress. This study was aimed to compare vitamin E-bonded dialyzer (PSVE) versus polyethersulfone membrane. Sixteen subjects with CVCs were included in a prospective two-arm crossover 12-month study. The primary endpoints were the rHuEPO requirement and the erythropoiesis-stimulating agents (ESA) index, which was defined by the ratio between weekly EPO dosage (IU/kg/week) and Hb levels (g/dl). The mean dosages of rHuEPO to maintain hemoglobin between 10.5 and 12 g/dl were 135 ± 59 and 101 ± 57 IU/kg/week with polysulfone and PSVE, respectively (P = 0.14). The ESA indexes were 12.1 ± 5.2 and 8.7 ± 5.2 (P < 0.0001) with polysulfone and PSVE, respectively. A trend towards consensual changes in protein glycoxidation, antioxidant, and inflammatory markers was observed. In conclusion, the study suggests a role for PSVE in the reduction of ESA index in HD patients with CVCs.

IL-1β receptor antagonist reduces inflammation in hemodialysis patients

Chronic inflammation is highly prevalent in maintenance hemodialysis (MHD) patients and associates with increased mortality. IL-1β, a pro-inflammatory cytokine, is elevated in MHD patients. A balance between IL-1β and its naturally occurring antagonist may determine the inflammatory response and its consequences in this population. We performed a pilot randomized placebo-controlled trial to evaluate the efficacy of the administration of recombinant human IL-1 receptor antagonist (IL-1ra) on biomarkers of inflammation and nutrition in MHD patients with three consecutive high sensitivity C-reactive protein (hsCRP) measurements >5 mg/L. We randomly assigned 22 patients to placebo or IL-1ra (1:1) for 4 weeks; 14 completed the trial. Patients in the IL-1ra arm had a 53% reduction in mean hsCRP compared with 1% in the placebo arm (P = 0.008), a 40% reduction in mean IL-6 levels compared with a 20% increase in the placebo arm (P = 0.03), and a 23% increase in mean prealbumin compared with 6% in the placebo arm (P = NS). In conclusion, the administration of IL-1ra in MHD patients can lower biomarkers of inflammation. Whether IL-1ra administration improves survival in this population requires additional long-term studies.

Vascular access type and changes in inflammatory markers in incident dialysis patients: a pilot study

PURPOSE

To determine the association between the initial hemodialysis (HD) vascular access type and short-term changes in inflammation markers.

METHODS

This is a prospective, observational study in incident chronic kidney disease (CKD) (stages 4 and 5) patients receiving their first HD vascular access. Serum samples were obtained pre-access placement, and 1 week, and 1 month post-access insertion. Samples were tested for high sensitivity C-reactive protein (hsCRP) and interleukin-6 (IL-6) using ELISA. Patients with known inflammatory states (infection, malignancy, connective tissue disorders, organ transplantation and those on immune modulating agents) were excluded. The hsCRP and IL-6 values were transformed into logarithmic scale. Chi-square analysis, independent and paired t-tests were performed where appropriate, and a two-way ANOVA with time as a repeated measure was also performed. Significance was determined at p=0.05.

RESULTS

One-month follow-up data was obtained in 48 patients (arteriovenous fistula (AVF), n=10; tunneled catheter (TC), n=28; arteriovenous graft (AVG), n=10). A significant increase in both hsCRP (p <0.05) and IL-6 (p=0.02) occurring 1 week after TC insertion was observed. Elevation of the IL-6 levels appeared to be sustained 1 month after TC insertion, although this finding was not statistically significant (p=0.68), whereas the hsCRP levels returned to baseline within 1 month. After AVG insertion only the hsCRP levels rose significantly (p=0.01) after 1 week and returned to baseline within 1 month. In the AVF group, inflammatory markers did not change for any time period.

CONCLUSIONS

In CKD patients, TC and AVG insertion result in a transient state of inflammation 1 week post-operatively, which is not observed after AVF surgery. Whether this is a persistent phenomenon after TC insertion requires a larger, longitudinal study.