Fibrinogen, coagulation factor VII, tissue plasminogen activator, plasminogen activator inhibitor-1, and lipid as cardiovascular risk factors in chronic hemodialysis and continuous ambulatory peritoneal dialysis patients

Secretory activity of the coronary artery endothelial cells in conditions of the peritoneal dialysis

Introduction

Endothelial dysfunction is frequent in patients treated with peritoneal dialysis and may lead to cardiac complications. We evaluated the effect of effluent dialysates and serum on the function of coronary artery endothelial cells (CAEC).

Methods

Human CAEC in in vitro culture were exposed to serum and dialysates from 24 patients treated with continuous ambulatory peritoneal dialysis (CAPD) and secretion of interleukin-6 (IL6), von Willebrand factor (vWF), tissue plasminogen activator (t-PA) and plasminogen activator inhibitor-1 (PAI-1) were measured. Modulation of the secretory activity of CAEC by Sulodexide, mixture of glycosaminoglycans: heparin sulfate and dermatan sulfate, was studied.

Results

Serum from CAPD patients stimulated synthesis of IL6 (+93%), vWF (+18%), and PAI-1 (+20%) and did not change t-PA secretion in CAEC. Dialysates stimulated secretion of IL6 (+89%), vWF (+29%), and PAI-1 (+31%) and did not change t-PA synthesis. Dialysates collected in 12 patients after 6 months more strongly stimulated synthesis of IL6 (+37%) and PAI-1 (+7%). Sulodexide suppressed the secretory activity of CAEC stimulated by the studied sera: IL6 (–38%), vWF (–19%), t-PA (–13%), and PAI-1 (–12%).

Conclusions

Serum and the dialysate from CAPD patients induce inflammatory and prothrombotic reaction in coronary arterial endothelial cells. The general pattern of the observed effects for serum and dialysates was similar but the intensity of the effects was not identical. Sulodexide reduced these effects.

Changes in hemostatic factors after kidney transplantation: A retrospective cohort study

Chronic kidney disease affects hemostasis in complex ways, producing both thrombotic and hemorrhagic diatheses. These changes may impact patient morbidity and mortality pre-transplantation, as well as allograft survival after kidney transplantation (KT). This study was conducted to analyze changes in hemostatic factors in the early post-KT period.We retrospectively analyzed 676 recipients of kidney allografts from December 2009 to December 2014. Patients receiving plasmapheresis pre- or post-KT, experiencing early allograft failure, or receiving anticoagulants or antiplatelet agents pre- or post-KT were excluded.Of the 367 included patients, acute (≤1 month) rejection occurred in 4.1% and delayed graft function occurred in 3.3%. Postoperative bleeding complications occurred in 7.9% of patients and thrombotic complications in 3.3%. Pre-transplantation, recipients had below normal hemoglobin, above normal d-dimer and homocysteine levels, and elevated rates of antiphospholipid antibodies. Hemoglobin increased to almost normal by postoperative day (POD) 28 (P  < .001). d-dimer increased on POD7, 14, and 28, although the values were not significantly different from pre-KT. The pattern of d-dimer changes suggested that they were a nonspecific consequence of major surgery. Homocysteine decreased to normal by POD7 (P  < .001). The percentage of patients with ≥1 prothrombotic factor was 82.0% pre-KT and only 14.2% on POD28 (P  < .001).The most of patients exhibited prothrombotic tendencies, including increased d-dimer and homocysteine, and increased prevalence of antiphospholipid antibodies before transplantation. They also had pre-transplantation anemia, suggesting a concomitant bleeding diathesis. However, most of these abnormal hemostatic factors improved or resolved after KT.

Hemodialysis-Related Complement and Contact Pathway Activation and Cardiovascular Risk: A Narrative Review

Individuals receiving long-term hemodialysis are at increased risk of developing cardiovascular disease (CVD). Traditional cardiovascular risk factors do not fully explain the high CVD risk in this population. During hemodialysis, blood interacts with the biomaterials of the hemodialysis circuit. This interaction can activate the complement system and the factor XII-driven contact system. FXII activation triggers both the intrinsic pathway of coagulation and the kallikrein-kinin pathway, resulting in thrombin and bradykinin production, respectively. The complement system plays a key role in the innate immune response, but also contributes to the pathogenesis of numerous disease states. Components of the complement pathway, including mannose binding lectin and C3, are associated with CVD risk in people with end-stage kidney disease (ESKD). Both the complement system and the factor XII-driven contact coagulation system mediate proinflammatory and procoagulant responses that could contribute to or accelerate CVD in hemodialysis recipents. This review summarizes what is already known about hemodialysis-mediated activation of the complement system and in particular the coagulation contact system, emphasizing the potential role these systems play in the identification of new biomarkers for CVD risk stratification and the development of potential therapeutic targets or innovative therapies that decrease CVD risk in ESKD patients.

Atrial Fibrillation and Ischemic Stroke: A Clinical Review

Atrial fibrillation (AF) is an important risk factor for ischemic stroke resulting in a fivefold increased stroke risk and a twofold increased mortality. Our understanding of stroke mechanisms in AF has evolved since the concept of atrial cardiopathy was introduced as an underlying pathological change, with both AF and thromboembolism being common manifestations and outcomes. Despite the strong association with stroke, there is no evidence that screening for AF in asymptomatic patients improves clinical outcomes; however, there is strong evidence that patients with embolic stroke of undetermined source may require long-term monitoring to detect silent or paroxysmal AF. Stroke prevention in patients at risk, assessed by the CHA₂DS₂-VASc score, was traditionally achieved with warfarin; however, direct oral anticoagulants have solidified their role as safe and effective alternatives. Additionally, left atrial appendage exclusion has emerged as a viable option in patients intolerant of anticoagulation. When patients with AF have an acute stroke, the timing of initiation or resumption of anticoagulation for secondary stroke prevention has to be balanced against the risk of hemorrhagic conversion. Multiple randomized clinical trials are currently underway to determine the best timing for administration of anticoagulants following acute ischemic stroke.

Thromboembolic and Bleeding Risk in Atrial Fibrillation Patients with Chronic Kidney Disease: Role of Anticoagulation Therapy

Atrial fibrillation (AF) and chronic kidney disease (CKD) are strictly related; several independent risk factors of AF are often frequent in CKD patients. AF prevalence is very common among these patients, ranging between 15% and 20% in advanced stages of CKD. Moreover, the results of several studies showed that AF patients with end stage renal disease (ESRD) have a higher mortality rate than patients with preserved renal function due to an increased incidence of stroke and an unpredicted elevated hemorrhagic risk. Direct oral anticoagulants (DOACs) are currently contraindicated in patients with ESRD and vitamin K antagonists (VKAs), remaining the only drugs allowed, although they show numerous critical issues such as a narrow therapeutic window, increased tissue calcification and an unfavorable risk/benefit ratio with low stroke prevention effect and augmented risk of major bleeding. The purpose of this review is to shed light on the applications of DOAC therapy in CKD patients, especially in ESRD patients.

Comparison of Hemostatic Disturbances between Patients on Capd and Patients on Hemodialysis

Objective

Disturbances in hemostasis are common findings in uremic patients. Both bleeding diathesis and thrombosis are observed. The purpose of this study was to assess whether renal replacement therapy in the form of hemodialysis (HD) or continuous ambulatory peritoneal dialysis (CAPD) affects coagulation and fibrinolysis in patients with end-stage renal failure.

Design

Comparison of hemostatic measures in patients on CAPD, HD, and matched healthy controls.

Setting

Department of Nephrology and Internal Medicine, Bialystok University School of Medicine.

Patients and Methods

Twenty-four HD patients and 23 CAPD patients were evaluated with respect to platelet aggregation, hemostatic parameters, serum lipids, lipoprotein(a), and cytokines [tumor necrosis factor alpha (TNFα) and interleukin-1 (IL-1)].

Interventions

Four exchanges of CAPD per day, using 2.0 L dialysate over a period of 25 ± 31 months; or 4 – 5 hours of HD 3 times per week for a period of 31 ± 22 months.

Results

Platelet aggregation in whole blood and platelet-rich plasma was significantly impaired in both groups of dialyzed patients compared to healthy volunteers. Markers of endothelial cell injury (thrombomodulin and von Willebrand factor) were significantly higher in HD and CAPD patients compared to the control group. A similar pattern of changes was observed for lipoprotein(a), fibrinogen, tissue factor pathway activity, and factor VII activity. Activity of factor X was significantly enhanced in CAPD compared to HD patients and controls. Euglobulin clot lysis time was significantly prolonged in HD and CAPD patients over controls, being more prolonged in CAPD patients. Markers of ongoing coagulation (thrombin–antithrombin complexes and prothrombin fragments 1+2) were higher in uremic patients, significantly higher in CAPD than in HD. A marker of ongoing fibrinolysis (plasmin–antiplasmin complexes) was higher in uremic patients but was lower in CAPD than in HD patients. Concentrations of TNFα and IL-1 were higher in HD than in CAPD patients.

Conclusion

Patients on CAPD showed evidence of a higher degree of hypercoagulation than HD patients. Thus, hemostatic abnormalities in end-stage renal failure may be affected to some extent by the choice of renal replacement therapy.

Dyslipidemia in Peritoneal Dialysis — Relation to Dialytic Variables

Objective

To investigate whether the specific lipoprotein (LP) abnormalities of peritoneal dialysis (PD) are associated with functional variables of this mode of dialysis.

Design

A survey of the LP profile in relation to peritoneal dialysis capacity (PDC) variables. The LP profile was compared to that of a group of age- and sex-matched controls.

Setting

The Peritoneal Dialysis Unit at Sahlgrenska University Hospital in Gothenburg, Sweden.

Patients

Twenty-two nondiabetic PD patients (5 women, 17 men) who had been on PD for at least 6 months.

Main Outcome Measures

The LP profile included plasma lipids, apolipoproteins (Apo), and individual ApoA- and ApoB-containing LP. The PDC measurement determined peritoneal glucose uptake, protein losses, effective peritoneal surface area, and total weekly creatinine clearance.

Results

The patients had been on PD for 6 to 48 months (mean 15.3 months) and had a total weekly creatinine clearance of 69.7 ± 13.3 L/1.73m2body surface area, an average peritoneal glucose uptake corresponding to 446 ± 162 kcal/24 hour, and a protein loss of 8.1 ± 2.5 g/24 hr. The patients had significantly higher total cholesterol (7.1 mmol/L), VLDL-cholesterol (1.0 mmol/L), LDL-cholesterol (4.7 mmol/L), and triglyceride levels (2.5 mmol/L); whereas the HDL-cholesterol level (1.2 mmol/L) was significantly lower than in controls. The PD patients had increased levels of ApoB-containing LPs, both of the cholesterol-rich LP-B and of the triglyceride-rich LP-B complex, reflected in higher plasma concentrations of ApoB, ApoC-III, and ApoE. Furthermore, they had significantly lower levels of LP-A-I:A-II, as well as of ApoA-I and ApoA-II. The LP-A-I:A-II and ApoA-II levels correlated inversely with the duration of PD treatment ( r = 0.54, p < 0.01 and r = 0.52, p < 0.05, respectively). The ApoA-II level was inversely correlated with the peritoneal surface area ( r = 0.53, p < 0.05). There were no other correlations between LP variables and PDC variables, nor did any of the LP variables correlate with peritoneal glucose uptake or protein losses.

Conclusion

The proatherogenic lipoprotein profile of patients on PD is characterized by increased concentrations of cholesterol-rich and triglyceride-rich ApoB-containing LPs. While the duration of treatment appears to have some influence on the development of this type of dyslipidemia, the pathophysiological links to the dialysis mode must be further explored.

A Comprehensive Study on Hemostasis in CAPD Patients Treated with Erythropoietin

Objective

Bleeding diathesis and simultaneous thrombotic complications may be seen in dialyzed patients. Erythropoietin (EPO) may shift the precarious balance of the hemostatic system toward thrombosis. Platelets and tissue factor (TF) play a major role in plug formation. Tissue factor pathway inhibitor (TFPI) appears to play a primary role in regulating TF-induced coagulation. Thrombin activatable fibrinolysis inhibitor (TAFI) is a key protein linking coagulation and fibrinolysis. The aim of the study was to assess whether 6 months of EPO therapy affects platelet function, that is, platelet aggregation and P-selectin level; moieties of the extrinsic coagulation pathway: TF, TFPI, and TFPI/Xa complexes, and factors VII and X; markers of ongoing coagulation: thrombin–antithrombin complexes (TAT) and prothrombin fragments 1+2; a marker of ongoing fibrinolysis: plasmin–antiplasmin complexes (PAP); fibrinolytic activity: euglobulin clot lysis time (ECLT); and markers of endothelial cell injury: von Willebrand factor, thrombomodulin, E-selectin, and TAFI, in continuous ambulatory peritoneal dialysis (CAPD) patients.

Patients and Methods

22 patients on CAPD were given EPO 6000 U/week. 12 patients with chronic renal failure and 12 healthy volunteers served as control groups. All parameters were studied before, and after 1, 3, and 6 months of EPO therapy.

Setting

Department of Nephrology and Internal Medicine, Medical Academy of Bialystok, Poland.

Results

Platelet aggregation in whole blood did not change significantly during EPO treatment. A significant rise in arachidonic acid-induced platelet aggregation in platelet-rich plasma was observed after 3 and 6 months, and in collagen-induced platelet aggregation after 6 months of EPO therapy, compared to the baseline values. The TFPI concentration decreased significantly after 6 months of EPO therapy. The activity of factor VII increased transiently after 1 month of EPO therapy, compared to the baseline values. The TAFI concentration and activity in the CAPD group were significantly higher than in the control group. Erythropoietin therapy resulted in a significant decrease in TAFI concentration and activity after 6 months of EPO treatment. The ECLT was shortened significantly as early as after 1 month of EPO therapy. Thrombomodulin, von Willebrand factor concentration and activity, PAP, TAT, TFPI/Xa complexes, prothrombin fragments 1+2, factor X activity, P-selectin, E-selectin, and lipoprotein(a) did not change significantly during EPO treatment.

Conclusion

Erythropoietin treatment has a minimal effect on hemostasis in CAPD patients. A tendency toward a decline in TAFI is of unknown clinical relevance so far, and awaits further research.

Influence of Simvastatin on Aspects of Thrombogenesis in CAPD Patients

← Background

Patients on continuous ambulatory peritoneal dialysis (CAPD) are prone to dyslipidemia and have a high risk of cardiovascular death. Statins show beneficial effects on serum lipids and thrombogenesis in various groups of patients, but prospective studies have so far not been performed on CAPD patients.

← Aim

To determine the effects of 6 month's treatment with simvastatin on platelet function and some hemostatic parameters, markers of endothelial cell injury, in 14 CAPD patients with hypercholesterolemia.

← Methods

Simvastatin was given in a dose of 10 mg at bedtime. Commercially available kits were used for all determinations.

← Results

Cholesterol and low density lipoprotein fell significantly as early as after 1 month of the therapy ( p < 0.001). Platelet aggregation in whole blood and plateletrich plasma was transiently decreased by simvastatin therapy. The fibrinolytic activity index increased significantly after 6 months of simvastatin administration ( p < 0.05), reaching values observed in the control group, whereas euglobulin clot lysis time, which was also significantly shortened after 6 months ( p < 0.05), did not reach values obtained in healthy volunteers. Vascular cell adhesion molecule, thrombomodulin, and protein Z decreased significantly after 3 months of the therapy ( p < 0.05, p < 0.05, and p < 0.01, respectively), whereas intercellular adhesion molecule decreased after 6 months ( p < 0.05). Vascular endothelial growth factor and its receptor, protein Z, total tissue factor pathway inhibitor (TFPI), TFPI/Xa complexes, and thrombin activatable fibrinolysis inhibitor concentration and activity fell significantly after 6 months of treatment with simvastatin (all p < 0.05). Tissue plasminogen activator concentration increased after 1 month ( p < 0.01 after 1 month, p < 0.05 after 3 and 6 months), whereas total homocysteine fell after 6 months of simvastatin therapy ( p < 0.05). Truncated TFPI decreased significantly as early as after 1 month of therapy ( p < 0.05 after 1 month, p < 0.01 after 3 and 6 months).

← Conclusion

Simvastatin is an effective hypolipemic agent in CAPD patients. It favorably affects platelet aggregation and the extrinsic coagulation pathway, improves fibrinolysis, and ameliorates endothelial dysfunction. Simvastatin might reduce the risk of thrombotic complications in CAPD patients.

Procalcitonin and Conventional Markers of Inflammation in Peritoneal Dialysis Patients and Peritonitis

Objectives

To determine the significance of a newly described marker of inflammation procalcitonin (PCT), and to investigate its relationship to conventional markers of inflammation, such as C-reactive protein (CRP), fibrinogen, and erythrocyte sedimentation rate (ESR), in patients on peritoneal dialysis (PD) and with peritonitis.

Design

A prospective, observational clinical study.

Setting

The Nephrology Division of a University-affiliated teaching hospital.

Patients and Methods

51 consecutive patients on PD were included in the study. Of this number, 16 developed peritonitis during the observational period. Baseline PCT, CRP, and fibrinogen concentrations and ESR of 51 PD patients were determined at a time point (TB) prior to any evidence of infection. These results were compared with laboratory values from 74 hemodialysis patients and 34 nonuremic control subjects. All PD patients then were followed prospectively for evidence of peritonitis. In addition to routine blood tests, including hemoglobin and leukocyte count, and routine biochemical tests, blood samples were taken to measure PCT, CRP, and fibrinogen concentrations and ESR at the time (T0) when patients first were diagnosed with PD peritonitis and also on the 4th (T4) and the 14th (T14) days after treatment for peritonitis was initiated. PCT was assayed by immunoluminometry.

Results

No significant difference was observed between baseline median serum PCT concentrations in PD and hemodialysis patients; however, in both groups, baseline median PCT concentrations were significantly higher than those of nonuremic controls ( p < 0.05). The 16 patients on PD who developed peritonitis had 21 PD peritonitis episodes during the study period. The increased PCT concentration observed at T0 in PD peritonitis episodes decreased with therapy, and this change was statistically significant ( p < 0.05). In a receiver operating characteristic curve analysis for peritonitis, the area under the curve (AUC) for PCT was 0.80, which was significantly lower than the AUC for CRP and greater than the AUCs for fibrinogen and ESR. The sensitivity of PCT for peritonitis was lower than the sensitivity of conventional markers of inflammation; however, the specificity of PCT was higher.

Conclusions

Median serum PCT concentration in PD patients was significantly higher than in nonuremic controls but not hemodialysis patients. Serum PCT concentrations may serve as a useful adjunct to traditional markers of inflammation in detecting and monitoring inflammation and peritonitis in PD patients.

MicroRNA-497/fibroblast growth factor-23 axis, a predictive indictor for decreased major adverse cardiac and cerebral event risk in end-stage renal disease patients who underwent continuous ambulatory peritoneal dialysis

OBJECTIVE

This study aimed at exploring the correlation of microRNA (miR)-497/fibroblast growth factor-23 (FGF-23) axis with major adverse cardiac and cerebral event (MACCE) occurrence in end-stage renal disease (ESRD) patients who underwent continuous ambulatory peritoneal dialysis (CAPD).

METHODS

Totally, 360 ESRD patients who underwent CAPD were enrolled. Their plasma samples were collected to detect miR-497 expression by real-time quantitative polymerase chain reaction, and FGF-23 level by enzyme-linked immunosorbent assay. All patients were followed up for 36 months, and the occurrence of MACCE during the follow-up was documented.

RESULTS

MiR-497 expression negatively correlated with FGF-23 level in ESRD patients who underwent CAPD (P < .001). The MACCE occurrence rate at 1, 2, and 3-year was 5.6%, 11.9%, and 15.0%, respectively. Furthermore, miR-497/FGF-23 axis high level (P < .001) and miR-497 high expression (P = .034) correlated with reduced accumulating MACCE occurrence, whereas FGF-23 high level (P = .008) correlated with increased accumulating MACCE occurrence. Forward stepwise multivariate Cox's regression disclosed that miR-497/FGF-23 axis high level (P = .008) was an independent predictive factor for lower accumulating MACCE occurrence, whereas age (≥55 years) (P < .001), body mass index (≥21.7 kg/m² ) (P = .006), peritoneal dialysis duration (≥61.0 months) (P < .001), C-reactive protein (≥4.7 mg/L) (P = .001), serum uric acid (≥409.4 μmol/L) (P = .009), β-fibrinogen (≥5.8 mmol/L) (P < .001), and low-density lipoprotein cholesterol (≥2.7 mmol/L) (P = .003) were independent factors for predicting higher accumulating MACCE occurrence.

CONCLUSION

MiR-497/FGF-23 axis holds clinical significance for predicting attenuated MACCE risk in ESRD patients who underwent CAPD.

N-Acetylcysteine and Sulodexide Reduce the Prothrombotic Effect of Uremic Serum on the Venous Endothelial Cells

BACKGROUND/AIMS

Thromboembolic episodes are a frequent problem in end stage renal failure patients. The pathomechanism of the disorder is complex, including bioincompatibility of renal replacement therapy, endothelial dysfunction, increased blood level of procoagulant factors and uremic toxins. We studied changes in the functional properties of venous endothelial cells (VEC) in the presence of uremic serum and evaluated their possible modulation by N-acetylcysteine (NAC) or sulodexide (SUL).

METHODS

Serum samples from 12 uremic patients treated with hemodialysis were studied ex vivo on in vitro cultured VEC. In separate experiments, NAC 1 mmol/L or SUL 0.5 LRU/mL were added to uremic serum samples. Both changes in the gene expression and secretory activity of VEC were studied.

RESULTS

Uremic serum increased the expression of the following genes: IL6 +97%, p < 0.002; VEGF +28%, p < 0.002; vWF +47%, p < 0.002; PECAM +76%, p < 0.002; ICAM-1 +275%, p < 0.002; t-PA +96%, p < 0.002. Changes in gene expression were reflected by the increased secretory activity of VEC treated with the uremic serum. Exposure of VEC to uremic serum supplemented with NAC or SUL resulted in weaker stimulation of the studied genes' expression. Also, secretion of the studied solutes, with the exception of ICAM-1, was reduced in the presence of NAC: IL6 -34%, p < 0.01; VEGF -40%, p < 0.005; vWF -25%, p < 0.001; t-PA -47%, p < 0.01, and MMP9 -37%, p < 0.001. SUL reduced the uremic serum-induced secretion of all solutes: IL6 -24%, p < 0.05; ICAM-1 -43%, p < 0.01; VEGF -38%, p < 0.01; vWF -23%, p < 0.01; t-PA -49%, p < 0.01, and MMP9 -25%, p < 0.05.

CONCLUSIONS

Uremic serum induces prothrombotic changes in VEC, which may cause a predisposition to thrombotic disorders in patients with renal failure. NAC and SUL reduce the effects of the uremic serum in VEC, which suggests their potential therapeutic application in uremic patients.

Preemptively and non-preemptively transplanted patients show a comparable hypercoagulable state prior to kidney transplantation compared to living kidney donors

To prevent renal graft thrombosis in kidney transplantation, centres use different perioperative anticoagulant strategies, based on various risk factors. In our centre, patients transplanted preemptively are considered at increased risk of renal graft thrombosis compared to patients who are dialysis-dependent at time of transplantation. Therefore these patients are given a single dose of 5000 IU unfractionated heparin intraoperatively before clamping of the vessels. We questioned whether there is a difference in haemostatic state between preemptively and non-preemptively transplanted patients and whether the distinction in intraoperative heparin administration used in our center is justified. For this analysis, citrate samples of patients participating in the VAPOR-1 trial were used and several haemostatic and fibrinolytic parameters were measured in 29 preemptively and 28 non-preemptively transplanted patients and compared to 37 living kidney donors. Sample points were: induction anaesthesia (T1), 5 minutes after reperfusion (T2) and 2 hours postoperative (T3). At T1, recipient groups showed comparable elevated levels of platelet factor 4 (PF4, indicating platelet activation), prothrombin fragment F1+2 and D-dimer (indicating coagulation activation) and Von Willebrand Factor (indicating endothelial activation) compared to the donors. The Clot Lysis Time (CLT, a measure of fibrinolytic potential) was prolonged in both recipient groups compared to the donors. At T3, F1+2, PF4 and CLT were higher in non-preemptively transplanted recipients compared to preemptively transplanted recipients. Compared to donors, non-preemptive recipients showed a prolonged CLT, but comparable levels of PF4 and D-dimer. In conclusion pre-transplantation, preemptively and non-preemptively transplanted patients show a comparable enhanced haemostatic state. A distinction in intraoperative heparin administration between preemptive and non-preemptive transplantation does not seem justified.

Association of adipokines with blood pressure, arterial elasticity and cardiac markers in dialysis patients: cross-sectional analysis of baseline data from a cohort study

Background

Adipokines are a set of cytokines secreted by white adipose tissue that have been suggested to be involved in the development of cardiovascular diseases. We aimed to evaluate the cross-sectional associations of a panel of representative adipokines with cardiovascular measures in a cohort of hemodialysis patients.

Methods

We measured plasma adiponectin, resistin, plasminogen activator inhibitor-1 (PAI-1), leptin, monocyte chemotactic protein 1 (MCP-1) and adipsin levels in 366 dialysis patients and 60 healthy controls. The associations of these adipokines with systolic blood pressure (assessed by ambulatory blood pressure monitoring), pulse wave velocity (PWV) and cardiac markers (BNP, NT-proBNP, Troponin I, Troponin T) in these patients were determined by general linear models with stepwise adjustment for covariates.

Results

In unadjusted comparison with controls, dialysis patients showed increased adiponectin, resistin, MCP-1 and adipsin levels, decreased PAI-1 concentrations (all p <0.001) and similar leptin levels (p = 0.82). On adjustment for body mass index and diabetes, however, the PAI-1 level was comparable between group (p = 0.06), whereas leptin levels became significantly higher in the patients(p <0.001). Higher adiponectin, lower PAI-1 and leptin levels were associated with higher systolic blood pressure, even after extensive adjustment (all p ≤ 0.01). Adiponectin was also consistently and inversely associated with PWV in fully adjusted models (p = 0.003). Resistin, PAI-1, leptin and adipsin showed negative associations with one or more circulating cardiac markers (all p ≤ 0.02).

Conclusions

We found significant associations between adipokines and cardiovascular measures. Our data suggest the possible involvement of adipokines in cardiovascular modulation in dialysis patients.

Electronic supplementary material

The online version of this article (doi:10.1186/s12986-017-0185-3) contains supplementary material, which is available to authorized users.

Pre-transplant dialysis modality does not influence short- or long-term outcome in kidney transplant recipients: analysis of paired kidneys from the same deceased donor

Previous studies have reported contradictory results regarding the effect of pre-transplant dialysis modality on the outcomes after kidney transplantation (KT). To minimize the confounding effect of donor-related variables, we performed a donor-matched retrospective comparison of 160 patients that received only one modality of pre-transplant dialysis (peritoneal dialysis [PD] and hemodialysis [HD] in 80 patients each) and that subsequently underwent KT at our center between January 1990 and December 2007. Cox regression models were used to evaluate the association between pre-transplant dialysis modality and primary study outcomes (death-censored graft survival and patient survival). To control for imbalances in recipient-related baseline characteristics, we performed additional adjustments for the propensity score (PS) for receiving pre-transplant PD (versus HD). There were no significant differences according to pre-transplant dialysis modality in death-censored graft survival (PS-adjusted hazard ratio [aHR]: 0.65; 95% confidence interval [95% CI]: 0.25-1.68) or patient survival (aHR: 0.58; 95% CI: 0.13-2.68). There were no differences in 10-year graft function or in the incidence of post-transplant complications either, except for a higher risk of lymphocele in patients undergoing PD (odds ratio: 4.31; 95% CI: 1.15-16.21). In conclusion, pre-transplant dialysis modality in KT recipients does not impact short- or long-term graft outcomes or patient survival.

An evidence-based review of edoxaban and its role in stroke prevention in patients with nonvalvular atrial fibrillation

Atrial fibrillation is the most common arrhythmia in the elderly. It is responsible for significant morbidity and mortality from cardioembolic complications like stroke. As a result, atrial fibrillation patients are risk-stratified using the CHADS2 or CHA2DS2-VASc scoring systems. Those at intermediate-to-high risk have traditionally been treated with therapeutic anticoagulation with warfarin for stroke prevention. Although effective, warfarin use is fraught with multiple concerns, such as a narrow therapeutic window, drug-drug and drug-food interactions, and excessive bleeding. Novel oral anticoagulant agents have recently become available as viable alternatives for warfarin therapy. Direct thrombin inhibitor dabigatran and factor Xa inhibitors like rivaroxaban and apixaban have already been approved by the US Food and Drug Administration (FDA) for stroke prevention in patients with nonvalvular atrial fibrillation. Edoxaban is the latest oral direct factor Xa inhibitor studied in the largest novel oral anticoagulant trial so far: ENGAGE AF-TIMI 48. Treatment with a 30 mg or 60 mg daily dose of edoxaban was found to be noninferior to dose-adjusted warfarin in reducing the rate of stroke and systemic embolism in patients with nonvalvular atrial fibrillation, with a lower incidence of bleeding complications and cardiovascular deaths. Edoxaban was recently reviewed by an FDA advisory committee and recommended as a stroke-prophylaxis agent. Once approved, it promises to provide another useful alternative to warfarin therapy.

Encapsulating peritoneal sclerosis-a rare but devastating peritoneal disease

Encapsulating peritoneal sclerosis (EPS) is a devastating but, fortunately, rare complication of long-term peritoneal dialysis. The disease is associated with extensive thickening and fibrosis of the peritoneum resulting in the formation of a fibrous cocoon encapsulating the bowel leading to intestinal obstruction. The incidence of EPS ranges between 0.7 and 3.3% and increases with duration of peritoneal dialysis therapy. Dialysis fluid is hyperosmotic, hyperglycemic, and acidic causing chronic injury and inflammation in the peritoneum with loss of mesothelium and extensive tissue fibrosis. The pathogenesis of EPS, however, still remains uncertain, although a widely accepted hypothesis is the "two-hit theory," where, the first hit is chronic peritoneal membrane injury from long standing peritoneal dialysis followed by a second hit such as an episode of peritonitis, genetic predisposition and/or acute cessation of peritoneal dialysis, leading to EPS. Recently, EPS has been reported in patients shortly after transplantation suggesting that this procedure may also act as a possible second insult. The process of epithelial-mesenchymal transition of mesothelial cells is proposed to play a central role in the development of peritoneal sclerosis, a common characteristic of patients on dialysis, however, its importance in EPS is less clear. There is no established treatment for EPS although evidence from small case studies suggests that corticosteroids and tamoxifen may be beneficial. Nutritional support is essential and surgical intervention (peritonectomy and enterolysis) is recommended in later stages to relieve bowel obstruction.

Leptin and plasminogen activator inhibitor-1 levels in children on chronic dialysis

PURPOSE

In this study, it is aimed to compare the serum leptin and PAI-1 levels and evaluate their relationship in children on hemodialysis (HD) and peritoneal dialysis (PD).

METHOD

Thirty-six patients on HD (mean age: 15.0 ± 2.8 years), 19 patients on PD (mean age: 13.0 ± 3.5 years) and 15 healthy subjects (mean age: 14.5 ± 2.7 years) were included in the study. Laboratory investigations included blood count, biochemical parameters, serum iron, iron binding capacity, parathormone, erythrocyte sedimentation rate, C-reactive protein (CRP), prothrombin time (PT), partial thromboplastin time (PTT), fibrinogen, serum leptin and PAI-1 levels.

RESULTS

Serum leptin levels were significantly higher in HD group than in control group when the effects of BMI and sex were controlled, while PD and control groups had similar leptin levels. PAI-1 levels were also significantly higher in HD group than in control group, while there was no statistically significant difference in PAI-1 levels of PD and control group. PAI-1 levels and leptin levels were significantly correlated, which was independent of the effect of BMI in both HD and PD groups when they are evaluated separately.

CONCLUSION

Results of our study showed that HD patients had higher leptin and PAI-1 levels and leptin and PAI-1 levels were correlated significantly in both patient groups. The effect of elevated serum leptin and PAI-1 levels on the cardiovascular complications remains to be established.

Increased plasminogen activator inhibitor-1 levels in patients with isolated coronary artery ectasia

Isolated coronary artery ectasia (ICAE) is defined as the ectasia of the coronary arteries without concomitant coronary artery stenosis. The etiology and the clinical course of ICAE are still not clear. Increased levels of plasminogen activator inhibitor-1 (PAI-1) inhibit vasa vasorum, leading to diminished vessel wall supply and thus contributes to aortic aneurysm expansion. Whether the same process has role in coronary artery ectasia is not known. The aim of this study is to investigate the association between PAI-1 and coronary artery ectasia in patients without concomitant obstructive coronary artery disease. Among 2830 patients who underwent coronary angiography between March 2010 and 2011, 55 patients (40 male, 15 female, mean age 60 ± 8 years) with ICAE, formed our study group. 27 patients with similar patient characteristics, with angiographically proven normal coronary arteries, were enrolled as the control group. The basal characteristics were similar between two groups. PAI-1 levels were statistically higher in the ICAE group compared to the control group (104.13 ± 56.65 and 63.39 ± 35.01 ng/dl, respectively) (P = 0.008). A significant positive correlation between CAE and PAI-1 (r = 0.358, P = 0.007) was also demonstrated. Serum high sensitive C reactive protein (hsCRP) levels did not differ between two groups (P > 0.05). The plasma PAI-1 levels were significantly higher in ICAE patients compared to normal coronary artery group. Increased PAI-1 levels may diminish vasa vasorum by antiangiogenic activity leading to coronary ectasia.

An evidence-based review of apixaban and its potential in the prevention of stroke in patients with atrial fibrillation

Atrial fibrillation (AF) is a common cardiac arrhythmia, especially in the elderly population. It is associated with cardioembolic complications, particularly strokes, resulting in severe functional deficit or death. AF patients are first stratified into low, intermediate, and high risk for thromboembolic events using the CHADS(2) and CHA(2)DS(2)-VASc score systems. Depending on their risks, patients are treated with either therapeutic anticoagulation with warfarin or acetylsalicylic acid for stroke prevention. Although warfarin is the recommended therapy, it is underutilized clinically due to concern for narrow therapeutic window, drug-to-drug and drug-to-food interactions, and hemorrhagic complications. Newer anticoagulant agents such as dabigatran (a direct thrombin inhibitor) and rivaroxaban (a direct factor Xa inhibitor) have already been approved by US Food and Drug Administration for stroke prevention in patients with nonvalvular atrial fibrillation. Apixaban is the newest oral direct factor Xa inhibitor and it has been extensively studied in the AVERROES and ARISTOTLE trials. Apixaban demonstrated reduced incidence of primary outcome of stroke and bleeding events when compared with warfarin. Apixaban is currently being reviewed by the Food and Drug Administration as a stroke prophylactic agent. In addition, there are several other indirect factor Xa inhibitors and vitamin K antagonists under study presently. Results from these studies will provide us with information about possible alternatives to warfarin.

Elevated plasma levels of PAI-1 predict cardiovascular events and cardiovascular mortality in prevalent peritoneal dialysis patients

BACKGROUND

Elevated plasminogen activator inhibitor-1 (PAI-1) levels are associated with increased cardiovascular (CV) risk in the general population. It has been shown that peritoneal dialysis (PD) patients have increased plasma levels of PAI-1. The aim of this study was to investigate whether PAI-1 independently predicted CV outcome in PD patients.

MATERIAL AND METHODS

Seventy-two PD patients (53% females, mean age 49.9 +/- 16.1 years) were studied. Twelve patients who underwent kidney transplantation and 14 patients who transferred to hemodialysis during follow-up were excluded from the analysis. The remaining 46 patients (54% female, mean age 54 +/- 16 years, dialytic age 42 +/- 30 months) were followed a mean time of 45.4 +/- 19.4 months (range 8-71 months). Baseline PAI-1, clinical, and laboratory parameters were assessed in all patients. Survival analyses were made with Kaplan-Meier and Cox regression analysis, with all-cause mortality and CV mortality and CV events (CVEs) as clinical end points.

RESULTS

During the follow-up, 29 patients died (17 from CV causes), and 28 fatal and non-fatal CVEs were recorded. The patients were divided according to plasma PAI-1 levels (i.e., <or= or >41 ng/mL). The significant independent predictors of all-cause of mortality were age (60 years; p = 0.018), CRP (5 mg/L; p = 0.015), and serum albumin (<3.5 g/L; p = 0.011). Multivariable Cox regression analysis showed that plasma PAI-1 41 ng/mL was independently predictive of higher CV mortality (p = 0.021) and CVEs (p = 0.001). The only other independent predictor of CV mortality was only CRP (5 mg/L; p = 0.008).

CONCLUSIONS

Plasma levels of PAI-1 41 ng/mL is a significant predictor of CV mortality and CVEs in PD patients.

Endogenous bradykinin contributes to increased plasminogen activator inhibitor 1 antigen following hemodialysis

Oxidative stress and inflammation predict cardiovascular events in chronic hemodialysis patients. Hemodialysis activates the kallikrein-kinin system, increasing bradykinin. Bradykinin promotes inflammation but also stimulates endothelial release of tissue-plasminogen activator and inhibits platelet aggregation. Understanding the detrimental and beneficial effects of endogenous bradykinin during hemodialysis has implications for the treatment of cardiovascular disease in the hemodialysis population. To test the hypothesis that bradykinin contributes to the inflammatory and fibrinolytic responses to dialysis, we conducted a double-blind, randomized, placebo-controlled crossover study comparing the effect of the bradykinin B(2) receptor blocker HOE-140 with vehicle on markers of oxidative stress, inflammation, fibrinolysis, and coagulation in nine hemodialysis patients without coronary artery disease. Bradykinin receptor antagonism did not affect the mean arterial pressure or heart rate response to dialysis. Monocyte chemoattractant protein 1 (MCP-1) peaked postdialysis; HOE-140 blunted the increase in MCP-1 (5.9 +/- 5.9 versus 25.6 +/- 20.1 pg/ml, P = 0.01). HOE-140 also abolished the increase in plasminogen activator inhibitor 1 (PAI-1) antigen observed at the end of dialysis. In contrast, HOE-140 significantly accentuated the effect of dialysis on F(2)-isoprostanes and P-selectin. Taken together, these results suggest that endogenous bradykinin contributes to increases in MCP-1 and PAI-1 antigen after hemodialysis via its B(2) receptor. Factors that increase the production of bradykinin or decrease its degradation may enhance the inflammatory response to hemodialysis.

Effect of Dialysis Type on Serum Lipids, Apolipoproteins, and Lipoproteins

AIM

Dyslipidemia is common among patients with end-stage renal disease, whether treated by hemodialysis (HD) or peritoneal dialysis (PD). However, there are not enough data about the effect of dialysis type on serum lipoprotein (a) [Lp(a)], apolipoprotein (a) [Apo(a)], apolipoprotein (b) [Apo(b)], and lipid levels. The aim of this study was to determine the effect of dialysis type on serum lipid levels.

MATERIALS AND METHODS

This study enrolled 40 HD patients (20 men and 20 women, aged 48.1 +/- 17.6 years) and 69 PD patients (35 men and 34 women, aged 45.2 +/- 16.3 years). Serum lipid profile including total cholesterol (TC), low-density lipoprotein (LDL-C), high-density lipoprotein (HDL-C), triglyceride (TG), Apo(a), Apo(b), and Lp(a) were determined in HD and PD patients. Patients who have used statins within the last six months were not included in the study.

RESULTS

No significant differences in TC, LDL-C, HDL-C, TG, Apo(a), Apo(b), or Lp(a) serum levels were found between HD and PD patients. Serum TC, LDL-C, HDL-C, TG, Apo(a), Apo(b), and Lp(a) in HD and PD patients were 172.2 +/- 42.7 (mg/dL) vs. 181.0 +/- 53.0 (mg/dL), 97.2 +/- 36.2 (mg/dL) vs. 101.4 +/- 33.6 (mg/dL), 45.3 +/- 11.9 (mg/dL) vs. 41.4 +/- 11.1 (mg/dL), 144.7 +/- 71.8 (mg/dL) vs. 173.0 +/- 76.8 (mg/dL), 1.2 +/- 0.5 (g/L) vs. 1.0 +/- 0.2 (g/L), 0.9 +/- 0.3 (g/L) vs. 1.2 +/- 0.3 (g/L), and 43.1 +/- 40.6 (mg/dL) vs. 46.0 +/- 42.7 (mg/dL), respectively.

CONCLUSION

The results of this study show that the maintenance CAPD treatment is associated with more pronounced alterations of the lipoproteins and lipid metabolism than those observed during HD treatment.

Effects of soy consumption on oxidative stress, blood homocysteine, coagulation factors, and phosphorus in peritoneal dialysis patients

OBJECTIVE

We studied the effects of soy consumption on oxidative stress, blood homocysteine, coagulation factors, and phosphorus in peritoneal dialysis patients.

DESIGN

This was an unblinded, randomized clinical trial.

SETTING

This study involved peritoneal dialysis centers in Tehran, Iran.

PATIENTS

We included 40 peritoneal dialysis patients (20 males and 20 females).

INTERVENTION

Peritoneal dialysis patients were randomly assigned to either a soy or control group. Patients in the soy group received 28 g/day textured soy flour (containing 14 g of soy protein) for 8 weeks, whereas patients in the control group received their usual diet, without any soy.

MAIN OUTCOME MEASURES

Blood oxidized low-density lipoprotein (ox-LDL), homocysteine, phosphorus, fibrinogen concentrations, and the activities of coagulation factors VII, IX, and X were measured at baseline and at the end of week 8 of the study.

RESULTS

The percentage of plasma coagulation factor IX activity decreased significantly by 17% in the soy group at the end of week 8 compared with baseline (P < .01), and the reduction was significant compared with the control group (P < .05). There were no significant differences between the two groups in mean changes of blood ox-LDL, homocysteine, phosphorus, fibrinogen concentrations, and the activities of coagulation factors VII and X.

CONCLUSION

Soy consumption reduces plasma coagulation factor IX activity, which is a risk factor for thrombosis in peritoneal dialysis patients.

Impact of proteinuria and glomerular filtration rate on risk of thromboembolism in atrial fibrillation: the anticoagulation and risk factors in atrial fibrillation (ATRIA) study

BACKGROUND

Atrial fibrillation (AF) substantially increases the risk of ischemic stroke, but this risk varies among individual patients with AF. Existing risk stratification schemes have limited predictive ability. Chronic kidney disease is a major cardiovascular risk factor, but whether it independently increases the risk for ischemic stroke in persons with AF is unknown.

METHODS AND RESULTS

We examined how chronic kidney disease (reduced glomerular filtration rate or proteinuria) affects the risk of thromboembolism off anticoagulation in patients with AF. We estimated glomerular filtration rate using the Modification of Diet in Renal Disease equation and proteinuria from urine dipstick results found in laboratory databases. Patient characteristics, warfarin use, and thromboembolic events were ascertained from clinical databases, with validation of thromboembolism by chart review. During 33,165 person-years off anticoagulation among 10,908 patients with AF, we observed 676 incident thromboembolic events. After adjustment for known risk factors for stroke and other confounders, proteinuria increased the risk of thromboembolism by 54% (relative risk, 1.54; 95% CI, 1.29 to 1.85), and there was a graded, increased risk of stroke associated with a progressively lower level of estimated glomerular filtration rate compared with a rate > or =60 mL x min(-1) x 1.73 m(-2): relative risk of 1.16 (95% CI, 0.95 to 1.40) for estimated glomerular filtration rate of 45 to 59 mL x min(-1) x 1.73 m(-2) and 1.39 (95% CI, 1.13 to 1.71) for estimated glomerular filtration rate <45 mL x min(-1) x 1.73 m(-2) (P=0.0082 for trend).

CONCLUSIONS

Chronic kidney disease increases the risk of thromboembolism in AF independently of other risk factors. Knowing the level of kidney function and the presence of proteinuria may improve risk stratification for decision making about the use of antithrombotic therapy for stroke prevention in AF.

Characterization of the pro-thrombotic state in CAPD patients

PURPOSE

To investigate whether a chronic pro-thrombotic tendency, which may contribute to a high rate of atherothrombotic disease, is present in patients treated for continuous peritoneal dialysis (CAPD), and, if so, what its pattern is. We investigated this issue by jointly exploring all the systems involved, the coagulation and fibrinolytic systems and platelets.

METHODS

Markers of coagulation activation, markers of fibrinolysis activation, and standard fibrinolytic parameters and platelet aggregation induced by different agents were measured in 15 patients treated by CAPD and in 15 matched, healthy controls. All CAPD patients received erythropoietin, were in the stable condition, and did not have acute disease or malignancy.

RESULTS

CAPD patients had substantially (p < 0.001) increased levels of prothrombin fragments F1+2, disclosing a low-grade activation of the coagulation system. D-dimer was also significantly (p < 0.05) increased, whereas the levels of t-PA antigen and activity, PAI antigen and activity, and plasminogen were comparable to controls, suggesting that slight secondary (and not primary) activation of fibrinolysis due to coagulation activation took place. Patients had significantly (p < 0.05) elevated levels of fibrinogen. A study of platelet aggregation (induced by adenosine diphosphate, collagen, and epinephrine) did not show platelet hyperactivity in patients.

CONCLUSIONS

We found that a pro-thrombotic tendency is present in the plasma of CAPD patients. The main reason for a pro-thrombotic state is chronic low-grade activation of the coagulation system and elevated levels of fibrinogen. The fibrinolytic system and platelets seemingly do not contribute to this pro-thrombotic tendency.

[Cardiovascular morbidity and mortality risk factors in peritoneal dialysis patients]

Cardiovascular (CVS) morbidity and mortality in the end-stage renal disease (ESRD) patients on peritoneal dialysis therapy is 10-30 folds higher than in general population. The prevalence of well known traditional risk factors such as age, sex, race, arterial hypertension, hyperlipidaemia, diabetes, smoking, physical inactivity is higher in the uraemic patients. Besides these, there are specific, nontraditional risk factors for dialysis patients. Mild inflammation present in peritoneal dialysis (PD) patients which can be confirmed by specific inflammatory markers is the cause of CVS morbidity and mortality in these patients. Hypoalbuminaemia, hyperhomocysteinaemia and a higher level of leptin are important predictors of vascular complications as well as CVS events in the PD patients. Plasma norepinephrine, an indicator of sympathetic activity, is high in the ESRD patients and higher in the PD patients than in the patients on haemodialysis (HD). Therefore, norepinephrine may be a stronger risk factor in the PD patients. The same applies to asymmetric dimethylargine (ADMA), an endogenous inhibitor of nitric oxide synthase, which is an important risk factor of CVS morbidity and mortality 15 % higher in the PD than the HD patients. Hyperphosphataemia, secondary hyperparathyroidism and high calcium x phosphate product have been associated with the progression of the coronary artery calcification and valvular calcifications and predict all-cause CVS mortality in the PD patients. Residual renal function (RRF) declines with time on dialysis but is slower in the PD than the HD patients. RRF decline is associated with the rise of proinflammatory cytokines and the onset of hypervolaemia and hypertension which increase the risk of CVS diseases, mortality in general and CVS mortality. In conclusion, it is very important to establish all CVS risk factors in the PD patients to prevent CVS diseases and CVS mortality in this population.

Associations between apolipoprotein E gene polymorphism and plasminogen activator inhibitor-1 and atherogenic lipid profile in dialysis patients

BACKGROUND

Apolipoprotein-E (ApoE) gene polymorphism has an important role in lipoprotein metabolism and could participate in the development of cardiovascular diseases (CVD). Plasminogen activator inhibitor-1 (PAI-1) is also regarded as a risk factor for CVD. The aim of the present study is to further investigate the possible link(s) between ApoE gene polymorphism and plasma PAI-1 antigen and serum lipid profile in peritoneal dialysis (PD) and hemodialysis (HD) patients.

MATERIAL AND METHODS

We studied 72 PD patients (38 female, mean age 49.9 +/- 16.1 years), 72 HD patients (22 female, mean age 57.4 +/- 14.6 years), and 42 healthy subjects (21 female, mean age 50.1 +/- 18.6 years). Serum lipid parameters, plasma PAI-1 levels, and ApoE genotypes were determined in all subjects.

RESULTS

The distribution of ApoE genotypes and alleles frequencies was similar in dialysis patients and healthy controls. In PD patients, total cholesterol (TC), low-density lipoprotein (LDL)-C, and ApoB levels were significantly higher than that of HD patients. HD patients with E3/4 genotype had elevated TC, LDL-C and ApoB levels compared with E3/3 genotype. TC and triglyceride levels were also higher in E3/4 genotype than that of E2/3 genotype. PD and HD patients showed a significantly increased PAI-1 levels compared with controls, whereas PAI-1 levels were highest in HD patients. There was no significant relation between ApoE genotypes and PAI-1 levels.

CONCLUSIONS

The present study suggests that ApoE polymorphism significantly affects serum lipid profile in HD patients and epsilon4 allele carriers are more susceptible to have atherogenic lipid profile.

Tissue factor and urokinase-type plasminogen activator system are related to the presence of cardiovascular disease in hemodialysis patients

INTRODUCTION

The disturbances of haemostasis and enhanced oxidative stress (SOX) appear to contribute to the cardiovascular disease (CVD) in hemodialysis (HD) patients. The aim of the present study was to investigate if the disorders of coagulation/fibrinolysis system are associated with the presence of CVD in these patients.

MATERIALS AND METHODS

We compared pre-dialysis levels of uPA, suPAR, tissue factor (TF) and its inhibitor (TFPI), prothrombin fragment F1+2 (F1+2); a marker of SOX-Cu/Zn superoxide dismutase (Cu/Zn SOD) and a surrogate of inflammation-high sensitivity C-reactive protein (hs CRP) in HD patients with and without CVD.

RESULTS

The uPA/suPAR system and hs CRP values were significantly greater in patients with CVD than in those without CVD; whereas TF, TFPI, F1+2 and Cu/Zn SOD levels were comparable in both patient groups. TF was positively correlated with both uPA (p<0.001) and suPAR levels (p<0.05). Logistic regression analysis showed that elevated levels of suPAR, TF and uPA were independently associated with the presence of CVD in HD patients.

CONCLUSIONS

The association between TF and uPA/suPAR system is significantly related to the presence of CVD in HD patients.

Cardiovascular risk in chronic renal disease and transplantation prevention and management

Cardiovascular disease (CVD) is the single best predictor of mortality in patients with chronic kidney disease and in kidney transplant recipients. These populations are considered to be at extraordinarily high risk for CVD and its complications. On the other hand, renal dysfunction should be considered as a CVD risk factor. The management of CVD in patients with chronic kidney disease is a special challenge for clinicians. In this article, major risk factors for CVD are presented, as well as diagnosis of coronary artery disease, acute coronary syndromes, its treatment modalities (pharmacological therapy and coronary revascularisation procedures), and outcomes in patients with chronic renal failure and kidney allograft recipients.

Effect of dialysis modality on plasma fibrinogen concentration: A meta-analysis

BACKGROUND

Concentrations of plasma fibrinogen, a vascular risk factor, tend to be greater in patients on peritoneal dialysis (PD) than hemodialysis (HD) therapy, like concentrations of serum cholesterol, lipoprotein(a), and transthyretin, despite the substantial loss of protein during PD. Worse vascular outcome has been noted in PD patients compared with HD patients in several studies.

METHODS

In this study, the mean difference in plasma fibrinogen levels (PD-HD) was quantified by means of meta-analysis of mean differences found in 12 cohorts with both PD and HD patients (set 1; N = 630) by using a fixed-effects model and meta-analysis of mean fibrinogen values reported in 30 cohorts of patients on a single dialysis modality (set 2; 8 PD cohorts, 22 HD cohorts; N = 2,096) by using a mixed model.

RESULTS

On meta-analysis, the weighted mean difference (PD-HD) was 105 mg/dL (95% confidence interval [CI], 86 to 124 [3.1 micromol/L; 95% CI, 2.5 to 3.6]) in set 1 and 103 mg/dL (95% CI, 53 to 153 [3.0 micromol/L; 95% CI, 1.6 to 4.5) in set 2.

CONCLUSION

Like other vascular risk factors, such as cholesterol and lipoprotein(a), plasma fibrinogen level is markedly greater in PD than HD patients, with an approximate difference of 100 mg/dL [2.9 mumol/L]. Different plasma reference ranges for fibrinogen need to be defined for PD and HD patients. The mechanism for the difference and the possible role of hyperfibrinogenemia in worsening vascular disease in PD patients deserve study.

Hypercoagulability in renal transplant recipients. Identifying patients at risk of renal allograft thrombosis and evaluating strategies for prevention

Renal transplantation improves survival and quality of life for patients with end-stage renal disease (ESRD). Improvements in immunosuppressive therapy have reduced early allograft loss due to acute rejection to very low levels. Early allograft loss, due to acute thrombotic complications, remains a constant and proportionally increasing complication of renal transplantation. Identifying risk factor(s) for thrombosis amenable to preventive strategies has been elusive. Epidemiological studies have attempted to define risk in terms of modifiable (drugs, dialysis modality, surgical procedure) and non-modifiable (age, diabetes mellitus, vascular anomalies) factors, or identify changes in coagulation or fibrinolysis promoting a more thrombotic state. Most recently the evolution of thrombophilia research has established the potential for inherited hypercoagulability to predispose to acute allograft thrombosis. Inheritance of the factor V Leiden (FVL), prothrombin G20210A mutation, or the presence of antiphospholipid antibodies (APA) may increase the risk of renal allograft thrombosis approximately 3-fold in selected patients. Patients with ESRD due to systemic lupus erythematosus (SLE) appear at particularly high risk of thrombosis, especially if they have either APA or detectable beta(2)-glycoprotein-1. Data for other hypercoagulable states such as hyperhomocystinemia or the C677T polymorphism of the methylenetetrahydrofolate reductase gene are deficient. Patients with APA, FVL, or prothrombin G20210A mutation also appear to have greater graft loss due to vascular rejection, possibly reflecting immunological injury upon the vascular wall exacerbated or induced by the prothrombotic state. While substantial in vitro data suggest cyclosporine is prothrombotic, an independent clinical association with allograft thrombosis is unproven. Interventions to reduce thrombotic risk including heparin, warfarin, and aspirin have been evaluated in both selected high-risk groups (heparin and warfarin) and unselected populations (heparin and aspirin). In unselected patients at low clinical risk, aspirin (75-150 mg/day) with or without a short period of unfractionated heparin (5000U twice a day for 5 days) appears to reduce the risk of renal allograft thrombosis significantly with a low risk of bleeding, especially when compared with low molecular weight heparins which risk accumulation in renal failure. In high-risk groups (identified thrombophilic risk factor, previous thrombosis, or SLE) longer period of heparin, with or without aspirin and maintenance with warfarin, should be considered. Re-transplantation following graft loss due to vascular thrombosis can be undertaken with a low risk of recurrence. Further prospective studies evaluating both putative risk factors and intervention strategies are required to determine whether routine clinical screening for thrombophilic factors is justified.

Hypercoagulable states and antithrombotic strategies in recurrent vascular access site thrombosis

Vascular access site thrombosis is a major cause of morbidity in patients receiving hemodialysis. The role of hypercoagulable states in recurrent vascular access site thrombosis remains poorly understood. Data are limited regarding systemic anticoagulation to improve access graft patency, because of concern about hemorrhagic complications. We determined the prevalence of hypercoagulable states and clinical outcome (thrombotic and hemorrhagic) after initiation of antithrombotic therapy in a series of patients with recurrent vascular access site thrombosis. We evaluated 31 patients who had sustained 119 thrombotic events that resulted in vascular access graft failure during the year before evaluation. Sixty-eight percent of patients tested had elevated concentrations of antibody to anticardiolipin or topical bovine thrombin, and 18% of patients tested had heparin-induced antibodies. More than 90% of patients had elevated factor VIII concentration, 62% had elevated fibrinogen concentrations, and 42% had elevated C-reactive protein concentrations. Twenty-nine patients were given antithrombotic therapy: 13 with warfarin sodium, 12 with unfractionated heparin (UFH), and 11 with low molecular weight heparin (LMWH). Seven patients received more than one antithrombotic agent, sequentially. Nineteen patients have had no thrombotic events since beginning antithrombotic therapy (10 with warfarin, 3 with UFH, 6 with LMWH). Mean follow-up was 8.6 months (median, 7 months). Eight patients sustained 10 bleeding complications (5 with warfarin, 3 with UFH, and 2 with LMWH). In conclusion, hypercoagulable states are common in patients with recurrent vascular access site thrombosis. Antithrombotic therapy may increase vascular access graft patency, but is associated with significant risk for hemorrhage. Prospective studies are needed to evaluate the role and safety of antithrombotic agents in improving vascular access graft patency.

Is a single time point C-reactive protein predictive of outcome in peritoneal dialysis patients?

C-reactive protein is the prototype marker of inflammation and has been shown to predict mortality in hemodialysis patients. However, it remains uncertain as to whether a single C-reactive protein level has similar prognostic significance in peritoneal dialysis patients. A single high-sensitivity C-reactive protein (hs-CRP) level was measured in 246 continuous ambulatory peritoneal dialysis patients without active infections at study baseline together with indices of dialysis adequacy, echocardiographic parameters (left ventricular mass index, left ventricular dimensions, and ejection fraction), nutrition markers (serum albumin, dietary intake, and subjective global assessment) and biochemical parameters (hemoglobin, lipids, calcium, and phosphate). The cohort was then followed-up prospectively for a median of 24 mo (range, 2 to 34 mo), and outcomes were studied in relation to these parameters. Fifty-nine patients died (36 from cardiovascular causes) during the follow-up period. The median hs-CRP level was 2.84 mg/L (range, 0.20 to 94.24 mg/L). Patients were stratified into tertiles according to baseline hs-CRP, namely those with hs-CRP < or = 1.26 mg/L, 1.27 to 5.54 mg/L, and > or = 5.55 mg/L. Those with higher hs-CRP were significantly older (P < 0.001), had greater body mass index (P < 0.001), higher prevalence of coronary artery disease (P = 0.003), and greater left ventricular mass index (P < 0.001). One-year overall mortality was 3.9% (lower) versus 8.8% (middle) versus 21.3% (upper tertile) (P < 0.0001). Cardiovascular death rate was 2.7% (lower) versus 5.2% (middle) versus 16.2% (upper tertile) (P < 0.0001). Multivariable Cox regression analysis showed that every 1 mg/L increase in hs-CRP was independently predictive of higher all-cause mortality (hazard ratio [HR], 1.02; 95% CI, 1.01 to 1.04; P = 0.002) and cardiovascular mortality (HR, 1.03; 95% CI, 1.01 to 1.05; P = 0.001) in peritoneal dialysis patients. Other significant predictors for all-cause mortality included age (HR, 1.07; 95% CI, 1.04 to 1.10), gender (HR, 0.49; 95% CI, 0.27 to 0.90), atherosclerotic vascular disease (HR, 2.65; 95% CI, 1.46 to 4.80), left ventricular mass index (HR, 1.01; 95% CI, 1.00 to 1.01) and residual GFR (HR, 0.53; 95% CI, 0.38 to 0.75). Age (HR, 1.06; 95% CI, 1.02 to 1.10), history of heart failure (HR, 3.31; 95% CI, 1.36 to 8.08), atherosclerotic vascular disease (HR, 3.20; 95% CI, 1.43 to 7.13), and residual GFR (HR, 0.57; 95% CI, 0.38 to 0.86) were also independently predictive of cardiovascular mortality. In conclusion, a single, random hs-CRP level has significant and independent prognostic value in PD patients.

Thrombosis in end-stage renal disease

Although renal failure has classically been associated with a bleeding tendency, thrombotic events are common among patients with end-stage renal disease (ESRD). A variety of thrombosis-favoring hematologic alterations have been demonstrated in these patients. In addition, "nontraditional" risk factors for thrombosis, such as hyperhomocysteinemia, endothelial dysfunction, inflammation, and malnutrition, are present in a significant proportion of chronic dialysis patients. Hemodialysis (HD) vascular access thrombosis, ischemic heart disease, and renal allograft thrombosis are well-recognized complications in these patients. Deep venous thrombosis and pulmonary embolism are viewed as rare in chronic dialysis patients, but recent studies suggest that this perception should be reconsidered. Several ESRD treatment factors such as recombinant erythropoietin (EPO) administration, dialyzer bioincompatibility, and calcineurin inhibitor administration may have prothrombotic effects. In this article we review the pathogenesis and clinical manifestations of thrombosis in ESRD and evaluate the evidence that chronic renal failure or its management predisposes to thrombotic events.

Elevations of inflammatory and procoagulant biomarkers in elderly persons with renal insufficiency

BACKGROUND

Renal insufficiency has been associated with cardiovascular disease events and mortality in several prospective studies, but the mechanisms for the elevated risk are not clear. Little is known about the association of renal insufficiency with inflammatory and procoagulant markers, which are potential mediators for the cardiovascular risk of kidney disease.

METHODS AND RESULTS

The cross-sectional association of renal insufficiency with 8 inflammatory and procoagulant factors was evaluated using baseline data from the Cardiovascular Health Study, a population-based cohort study of 5888 subjects aged > or =65 years. C-reactive protein, fibrinogen, factor VIIc, and factor VIIIc levels were measured in nearly all participants; interleukin-6, intercellular adhesion molecule-1, plasmin-antiplasmin complex, and D-dimer levels were measured in nearly half of participants. Renal insufficiency was defined as a serum creatinine level > or =1.3 mg/dL in women and > or =1.5 mg/dL in men. Multivariate linear regression was used to compare adjusted mean levels of each biomarker in persons with and without renal insufficiency after adjustment for other baseline characteristics. Renal insufficiency was present in 647 (11%) of Cardiovascular Health Study participants. After adjustment for baseline differences, levels of C-reactive protein, fibrinogen, interleukin-6, factor VIIc, factor VIIIc, plasmin-antiplasmin complex, and D-dimer were significantly greater among persons with renal insufficiency (P<0.001). In participants with clinical, subclinical, and no cardiovascular disease at baseline, the positive associations of renal insufficiency with these inflammatory and procoagulant markers were similar.

CONCLUSION

Renal insufficiency was independently associated with elevations in inflammatory and procoagulant biomarkers. These pathways may be important mediators leading to the increased cardiovascular risk of persons with kidney disease.

Inflammatory signals associated with hemodialysis

BACKGROUND

Inflammation is highly prevalent in chronic hemodialysis patients. Because hemodialysis involves the contact of blood with "foreign" surfaces, and the documented activation of several humoral and cellular pathways during the procedure, the hemodialysis procedure has been suggested as a potential source of inflammation in this patient population. Earlier studies did not provide clear-cut evidence of the potential contribution of the hemodialysis procedure to inflammation, as assessed by markers of inflammation such as cytokine levels and acute-phase protein production.

METHODS

Nine patients were studied using primed-constant infusion of l-(l-13C) leucine 2 hours before, during, and 2 hours after a single hemodialysis session. We evaluated the effects of hemodialysis on induction of interleukin-6 (IL-6) production as well as the fractional synthetic rates (FSR) of albumin and fibrinogen, two well-known acute-phase proteins.

RESULTS

During hemodialysis, albumin FSR and fibrinogen FSR increased significantly compared to the measurements obtained during baseline period. During this period, albumin and fibrinogen FSR increased 64% and 34%, respectively, compared to baseline (P < 0.05). While the increase in IL-6 concentration was modest during hemodialysis (14%), the levels further increased at the end of the 2-hour post-hemodialysis period (68% higher compared to baseline, P < 0.05). Fibrinogen FSR also demonstrated a further increase during the post-dialysis period (17% higher compared to the intradialytic period and 58% higher compared to baseline), while albumin FSR stabilized during this period.

CONCLUSIONS

The results provide clear evidence of hemodialysis-induced inflammatory response. The process is most notable during the 2-hour post-hemodialysis period.