Endothelial cell injury markers in chronic renal failure on conservative treatment and continuous ambulatory peritoneal dialysis

Atrial fibrillation, end-stage renal disease and hemorrhagic pleural-pericarditis

Pericarditis is the most common pericardial disease found in clinical practice, with an incidence of acute pericarditis reported in 27.7 cases per 100,000 subjects per year. Hemodialysis in end stage renal disease (ESRD) is associated with frequent cardiovascular modifications, mostly because of the highly fluctuating levels of potassium, magnesium, ionized calcium, sodium and volume status. The risk of arrhythmias is increased and chronic atrial fibrillation (AF) can be found among approximately 14% of patients. The renal disease combined with arrhythmias increases the risk of systemic thromboembolism but also of bleeding events. Here we present the case of a male patient, with ESRD, recently diagnosed with intradialytic paroxysmal AF for which oral anticoagulation therapy is initiated, but it’s early complicated with hemorrhagic pleural-pericarditis.

Intimal Hyperplasia and Arteriovenous Fistula Failure: Looking Beyond Size Differences

The development of venous intimal hyperplasia (IH) has been historically associated with failure of arteriovenous fistulas (AVF) used for hemodialysis. This long-standing assumption, based on histological observations, has been recently challenged by clinical studies indicating that the size of the intima by itself is not enough to explain stenosis or AVF maturation failure. Irrespective of this lack of association, IH is present in most native veins and fistulas, is prominent in many cases, and suggests a role in the vein that may not be reflected by its dimensions. Therefore, the contribution of IH to AVF dysfunction remains controversial. Using only clinical data and avoiding extrapolations from animal models, we critically discuss the biological significance of IH in vein remodeling, vascular access function, and the response of the venous wall to repeated trauma in hemodialysis patients. We address questions and pose new ones such as: What are the factors that contribute to IH in pre-access veins and AVFs? Do cellular phenotypes and composition of the intima influence AVF function? Are there protective roles of the venous intima? This review explores these possibilities, with hopes of rekindling a critical discussion about venous IH that goes beyond thickness and AVF outcomes.

Association between thrombomodulin and high mobility group box 1 in sepsis patients

BACKGROUND

High mobility group box 1 (HMGB1) has been studied as a molecule associated with severe outcomes in sepsis and thrombomodulin (TM) seems to decrease HMGB1 activity.

AIM

To investigate the role of the thrombomodulin/high mobility group box 1 (T/H) ratio in patients with sepsis and their association with their clinic, testing the hypothesis that higher ratios are associated with better outcomes.

METHODS

Twenty patients diagnosed with sepsis or septic shock, according to the 2016 criteria sepsis and septic shock (Sepsis-3), were studied. Patients were followed until they left the intensive care unit or until they achieved 28 d of hospitalization (D28). The following clinical outcomes were observed: Sequential Organ Failure Assessment (SOFA) score; Need for mechanical pulmonary ventilation; Presence of septic shock; Occurrence of sepsis-induced coagulopathy; Need for renal replacement therapy (RRT); and Death.

RESULTS

The results showed that patients with SOFA scores greater than or equal to 12 points had higher serum levels of TM: 76.41 ± 29.21 pg/mL vs 37.41 ± 22.55 pg/mL among those whose SOFA scores were less than 12 points, P = 0.003. The T/H ratio was also higher in patients whose SOFA scores were greater than or equal to 12 points, P = 0.001. The T/H ratio was, on average, three times higher in patients in need of RRT (0.38 ± 0.14 vs 0.11 ± 0.09), P < 0.001.

CONCLUSION

Higher serum levels of TM and, therefore, higher T/H ratio in the first 24 h after the diagnosis of sepsis were associated with more severe disease and the need for renal replacement therapy, while those with better clinical outcomes and those who were discharged before D28 showed a tendency for lower T/H ratio values.

Patency Rates After Successful Arteriovenous Fistula Thrombectomy: Relevance of the Flow/d-Dimer Ratio in the Decision-Making

OBJECTIVES

Surgical thrombectomy for acute arteriovenous fistula (AVF) thrombosis is one of the primary salvage intervention. The independent risk factors affecting the patency of AVF after a successful thrombectomy are yet unknown. Here, the author aimed to report the results of surgically corrected AVFs and the independent risk factors which may cause early failure following the surgical salvage.

METHODS

The study cohort comprised 24 patients who had acute AVF thrombosis and underwent successful surgical thrombectomy in the first 24 to 48 hours between January 2016 and April 2020 in our center. The study group was divided into patients with recurrent AVF thrombosis (n = 11, 45.8%) and without recurrent AVF thrombosis (n = 13, 54.1%) following surgical thrombectomy with a follow-up of 22.4 ± 6.8 months. Postthrombectomy primary and secondary patency of AVF were also evaluated.

RESULTS

The mean age of the cohort was 58.1 ± 15.2 years. A simple thrombectomy was performed for all cases. Only 2 cases have required a revision at the anastomosis due to severe intimal hyperplasia. Postthrombectomy primary patency rate was 45.5% for 18 months. Receiver operating characteristic analysis was performed with a resulting area under the curve value of 0.81 (95% CI: 0.35-0.94, P = .006) for flow (mL)/d-dimer (ng/mL) <0.63 in predicting recurrent AVF thrombosis following surgical thrombectomy.

CONCLUSIONS

Flow (mL)/d-dimer (ng/mL) <0.63 was independent predictor of recurrent thrombosis (RT) of a surgically salvaged AVF. The patients at risk for RT or who may benefit from further intervention should be identified with predictive parameters.

Soluble P-Selectin During a Single Hemodialysis Session in Patients With Chronic Renal Failure and Erythropoietin Treatment

In several studies, hemodialysis (HD) patients treated with recombinant human erythropoietin (rHuEPO) because of renal anemia showed increased levels of soluble adhesion molecules. The purpose of the study was to investigate the changes of soluble P-selectin (sSELP) and its relationship to platelet activation during a single HD session in patients with long-term rHuEPO treatment. Fifty-two HD patients with chronic renal failure were involved—26 with rHuEPO treatment (EPO group) and 26 without (non-EPO group). Thirty healthy subjects served as the control group. The sSELP, β-thromboglobulin, and platelet factor 4 plasma levels were measured before and after a single 4-hour HD session on a cuprophane dialyzer. The basal β-thromboglobulin and platelet factor 4 plasma levels were significantly increased in both HD groups compared with healthy controls but did not change after a single HD session, except for a significant decrease of platelet factor 4 in the non-EPO group. The predialysis sSELP plasma levels did not differ significantly compared with those of the healthy controls, but there was a significant increase of sSELP levels after a single HD session in both groups (EPO, P < .005; non-EPO, P < .05, respectively). These results suppose that the increased sSELP level was released from platelets during the course of a single HD session. The more significant increase of the sSELP plasma levels in EPO group during HD indicates that platelets are more activated in patients with long-term rHuEPO treatment, and this fact could partially explain the suspected tendency for thrombosis in these patients.

Low-grade risk of hypercoagulable state in patients suffering from diabetes mellitus type 2

OBJECTIVE

Diabetes, including type 1 and type 2, is associated with the hypercoagulable state. The aim of this study is to evaluate the concentration of selected hemostatic parameters and vascular endothelial growth factor-A (VEGF-A) in diabetic subjects.

METHODS

The study was conducted in 62 patients with diabetes. Group I consisted of 27 patients having uncontrolled diabetes with microalbuminuria and Group II included 35 well-controlled diabetic patients. The control group was made up of 25 healthy volunteers. In the citrate plasma, the concentrations of tissue factor (TF), tissue factor pathway inhibitor (TFPI), thrombin-antithrombin (TAT) complexes, and D-dimer were assayed. Serum concentrations of VEGF-A, lipid profile, creatinine, and plasma fasting glucose were measured and in the versene plasma the concentration of HbA1c was determined.

RESULTS

In the patients with uncontrolled diabetes, higher concentrations of TF, TFPI, and VEGF-A were observed, as compared with the well-controlled diabetics group and the control group. A significantly lower activity of antiplasmin was reported in patients from Group I as compared with the control group. In Group I, using the multivariate regression analysis, the glomerular filtration rate was independently associated with VEGF-A and dependently associated with total cholesterol.

CONCLUSIONS

The study showed higher concentrations of TF and TFPI in the patients with uncontrolled diabetes with microalbuminuria, which is associated with rapid neutralization of the thrombin formation, since TFPI inhibits the complex of TF/VIIa/Ca(2+). The manifestation of the above suggestions is the correct TAT complexes and D-dimer, which indicates a low grade of prothrombotic risk in this group of patients, but a higher risk of vascular complications.

Thrombosis in the uremic milieu--emerging role of "thrombolome"

Chronic kidney disease (CKD) is characterized by retention of a number of toxins, which unleash cellular damage. CKD environment with these toxins and a host of metabolic abnormalities (collectively termed as uremic milieu) is highly thrombogenic. CKD represents a strong and independent risk factor for both spontaneous venous and arterial (postvascular injury) thrombosis. Emerging evidence points to a previously unrecognized role of some of the prothrombotic uremic toxins. Here, we provide an overview of thrombosis in CKD and an update on indolic uremic toxins, which robustly increase tissue factor, a potent procoagulant, in several vascular cell types enhancing thrombosis. This panel of uremic toxins, which we term "thrombolome" (thrombosis and metabolome), represents a novel risk factor for thrombosis and can be further explored as biomarker for postvascular interventional thrombosis in patients with CKD.

The vascular endothelium and human diseases

Alterations of endothelial cells and the vasculature play a central role in the pathogenesis of a broad spectrum of the most dreadful of human diseases, as endothelial cells have the key function of participating in the maintenance of patent and functional capillaries. The endothelium is directly involved in peripheral vascular disease, stroke, heart disease, diabetes, insulin resistance, chronic kidney failure, tumor growth, metastasis, venous thrombosis, and severe viral infectious diseases. Dysfunction of the vascular endothelium is thus a hallmark of human diseases. In this review the main endothelial abnormalities found in various human diseases such as cancer, diabetes mellitus, atherosclerosis, and viral infections are addressed.

Stent thrombosis distal to the segment showing early in-stent restenosis with everolimus-eluting stent

Stent thrombosis remains a severe complication after deployment owing to its high mortality. In the current report, we present a case of stent thrombosis distal to the segment showing flow-limiting early in-stent restenosis with an everolimus-eluting stent. <Learning objective: Cardiologists should be aware of the potential risk of stent thrombosis in patients undergoing stent deployment distal to the segment where early restenosis is likely to occur.>.

Mechanism of endothelial dysfunction in chronic kidney disease

Endothelium is the largest organ in the body strategically located between the wall of blood vessels and the blood stream. The human body contains approximately 10(13) endothelial cells weighing approximately 1kg, and covering a surface area of 4000 to 7000m(2) equivalent to the soccer playground. Hypertension and shear stress, inflammation, diabetes-associated factors such as advanced glycated end products, and uremic toxins are some of the prevalent risk factors of endothelial dysfunction in chronic kidney disease. In renal failure endothelial dysfunction and atherosclerosis are almost universal, as well as cardiovascular complications. Endothelial cell damage or injury is invariably associated with such clinical conditions as thrombosis, hypertension, renal failure and atherosclerosis and may be also responsible for accelerated atherosclerosis in patients with chronic renal failure. Traditional risk factor cannot explain the high prevalence and incidence of cardiovascular disease in chronic kidney disease, therefore other non-traditional risk factors such as endothelial dysfunction, oxidative stress or insulin resistance have increasingly been studied. In this review paper mechanism of endothelial dysfunction, including the role of nitric oxide pathway, adipocytokines and hemodialysis-induced endothelial dysfunction is discussed.

Impact of systemic and local peritoneal inflammation on peritoneal solute transport rate in new peritoneal dialysis patients: a 1-year prospective study

BACKGROUND

The association between peritoneal solute transport rates (PSTRs) and inflammatory markers in patients on peritoneal dialysis (PD) is still under investigation. We aimed to elucidate their relationship during the first year on PD.

METHODS

We performed a prospective observational study with 187 incident PD patients who were treated with either biocompatible solution (BCS) or conventional solution (CS). Peritoneal dialysate effluent (PDE) and blood samples for the markers and the calculation of mass transfer area coefficient of creatinine (MTAC) were performed at 1, 6 and 12 months after commencing PD.

RESULTS

Of the 187 enrolled patients, 110 completed a 1-year study protocol. All PDE markers [interleukin-6 (IL-6), transforming growth factor-beta (TGF-beta), TGF-beta-induced gene-h3 (beta ig-h3), vascular endothelial growth factor (VEGF)] except CA125 increased over time, whereas PSTRs, high-sensitivity C-reactive protein (hs-CRP) and serum IL-6 levels did not change. Serum albumin and log PDE appearance rates (ARs) of IL-6, TGF-beta and CA125 predicted MTAC. The Delta value (12-month minus 1-month) of PDE AR of IL-6 was correlated with those of all other PDE markers. Both 12-month IL-6 and Delta IL-6 ARs in PDE were highest in the upper Delta MTAC tertile. PSTRs in the CS group, unlike BCS, had a tendency to increase over time, demonstrating a time-by-group interaction. Solution type and MTAC were not associated with patient and technique survival.

CONCLUSIONS

The change in PSTR during the first year of PD is related to PDE IL-6 AR, which may represent intraperitoneal inflammation; however, there does not seem to be a close association between PSTR and the degree of systemic inflammation.

Kynurenine pathway - a new link between endothelial dysfunction and carotid atherosclerosis in chronic kidney disease patients

PURPOSE

The endothelium dysfunction is an important component of atherosclertic cardiovascular disease. It has been also suggested that kynurenine pathway activation may be involved in the pathogenesis of this disease.

MATERIAL/METHODS

This is a cross-sectional study in chronic kidney disease (CKD) patients (n=106; 60 Males). The plasma markers of endothelial dysfunction and kynurenine (KYN), 3-hydroxykynurenine (3-HKYN), kynurenic acid (KYNA), anthranilic acid (AA) and quinolinic acid (QA) were measured in relation to an early indicator of the systemic atherosclerosis - intima-media thickness (IMT).

RESULTS

Kynurenines, von Willebrand factor (vWF), thrombomodulin (TM), soluble adhesion molecules (sICAM-1, sVCAM-1) and IMT in each uraemic group were significantly higher than in healthy people. In contrast, no significant differences in sE-selectin and sP-selectin concentrations were observed between CKD patients and controls. Kynurenines were positively associated with vWF, TM, sICAM-1 and sVCAM-1, whereas sP-selectin was inversely associated with the most of kynurenines. IMT was positively correlated both with kynurenines: KYN, 3-HKYN, QA as well as with endothelial markers: TM, vWF, sICAM-1 and sVCAM-1 (all p<0.01). Finally, multiple regression analysis identified age, vWF, sVCAM-1 and QA levels as the independent variables significantly associated with increased IMT in this population (adjusted r² = 0.51).

CONCLUSIONS

This study suggests a relationship between kynurenine pathway activation, endothelial dysfunction and the progression of atherosclerosis in CKD patients. It opens a new idea that the inhibition of kynurenine pathway may provide an effective strategy to slow down endothelial dysfunction and thereby the prevalence of atherosclerosis in this population.

Association of inflammation and protein-energy wasting with endothelial dysfunction in peritoneal dialysis patients

BACKGROUND

Cardiovascular disease is the main cause of mortality in end-stage renal disease (ESRD) patients. Recent studies have indicated that non-traditional risk factors such as endothelial dysfunction (ED), chronic inflammation and protein-energy wasting (PEW) may contribute significantly to the increased cardiovascular mortality among dialysis patients. To further ascertain this association, we carried out a cross-sectional assessment of nutritional status, inflammatory markers and endothelial dysfunction in peritoneal dialysis (PD) patients.

METHODS

We measured ED functionally by flow-mediated vasodilatation (FMD) using doppler ultrasonography and biochemically by soluble intercellular adhesion molecule-1 (sICAM-1) in 105 stable PD patients and 32 age- and sex-matched healthy controls. We also simultaneously measured inflammatory markers and performed a subjective global assessment (SGA) of their nutritional status using a seven-point scoring scale. Subjects were subgrouped according to their nutritional and inflammatory status.

RESULTS

In PD patients, FMD was markedly lower (9.9 +/- 4.8% vs. 16.4 +/- 4.8%, P < 0.05), and sICAM-1 was significantly higher than those in controls. The malnourished patients had significantly lower FMD (8.4+/-4.6% vs. 10.8+/-4.7%, P <0.05) and higher sICAM-1 than the nourished patients. The inflamed group had significantly lower FMD (7.1 +/- 3.8 vs.11.1 +/- 4.6%, P < 0.05) and higher sICAM-1 than the non-inflamed group. In all PD patients, lean body mass/body weight %, albumin and SGA correlated positively with FMD (r = +0.207, r = +0.224, r = +0.285, P < 0.05). However, age, log high sensitivity C-reactive protein (hsCRP), log IL-6 and sICAM-1 were negatively correlated with FMD (r = -0.275, r = -0.361, r = -0.360, r = -0.271, P < 0.05). A multiple regression analysis showed that log hsCRP was an independent factor affecting FMD. Endothelial function, demonstrated as FMD and sICAM-1 in the nourished PD patients without inflammation, was well preserved compared to other subgroups.

CONCLUSION

Our data suggest that chronic inflammation and PEW are closely linked to ED in PD patients.

Kynurenine and its metabolites--kynurenic acid and anthranilic acid are associated with soluble endothelial adhesion molecules and oxidative status in patients with chronic kidney disease

BACKGROUND

Cellular adhesion molecules and oxidative stress play a role in the pathogenesis of atherosclerosis in patients with chronic kidney disease (CKD). Recently, it has been postulated that the kynurenine (KYN) pathway could be involved in the pathogenesis of atherosclerosis.

METHODS

We evaluated the KYN, kynurenic acid (KYNA), anthranilic acid (AA), and their relations with cellular adhesion molecules: soluble intercellular adhesion molecule-1 (sICAM-1), soluble vascular adhesion molecule-1 (sVCAM-1), sE-selectin, sP-selectin, and Cu/Zn superoxide dismutase (Cu/Zn SOD) levels as the markers of oxidative stress in the population of 132 patients with CKD and 28 healthy controls.

RESULTS

Compared with the controls, 2 groups of dialyzed patients had significantly increased KYN (both P < 0.01), KYNA, AA, sICAM-1, sVCAM-1, and Cu/Zn SOD levels (all P < 0.001, respectively). KYN, AA, sICAM-1, and sVCAM-1 concentrations were significantly higher in undialyzed patients with CKD compared with healthy subjects (P < 0.001, P < 0.01, and both P < 0.05, respectively). sICAM-1 and sVCAM-1 were positively associated with KYN (P < 0.0001 and P < 0.01), KYNA (P < 0.05 and P < 0.0001), AA (P < 0.01 and P < 0.0001), and with Cu/Zn SOD (both P < 0.0001, respectively) in the whole CKD group. The positive relationship existed between sICAM-1, sVCAM-1 and age, high-sensitivity C-reactive protein, creatinine, and the duration of dialysis therapy. Multivariable analysis showed that KYN was a strong independent correlate of sICAM-1, whereas Cu/Zn SOD and platelets independently and significantly predicted sVCAM-1 in patients with CKD.

CONCLUSIONS

This study demonstrated that KYN is independently and significantly associated with elevated sICAM-1, whereas oxidative status and platelets independently and significantly predicted increased sVCAM-1 levels in patients with CKD.

Plasma markers of coagulation and endothelial activation in Fabry disease: impact of renal impairment

BACKGROUND

In Fabry disease, storage of globotriaosylceramide (Gb3) in arterial walls is one of the main pathogenetic factors that are thought to underlie the clinical manifestations of the disease. Abnormalities of the vessel wall, haemodynamics and pro- and anticoagulant factors may play a role, though the exact pathophysiology is incompletely understood. In this study, we try to clarify inconsistencies regarding coagulation activation, fibrinolysis, platelet activation and endothelial activation in 36 patients with Fabry disease.

METHODS

Cell-derived microparticles, markers for coagulation activation (F(1+2), TAT, sTF, sEPCR), fibrinolysis (D-dimer, tPA, alpha(2)-AP), platelet activation (beta-TG, PF4), endothelial activation (vWF) and acute phase response (IL-6, CRP) were studied in relation to renal function and severity of the disease and compared to data from 36 age- and sex-matched healthy controls (17 males).

RESULTS

Markers for endothelial activation and fibrinolysis were normal. Male patients had elevated levels of sTF and beta-TG, with an association between sTF and renal function and severity of the disease. In female patients, levels of TAT, beta-TG, PF4, CD63-positive platelet-derived microparticles and IL-6 were somewhat increased, with no correlation with renal function or disease severity.

CONCLUSIONS

Only minimal abnormalities in markers for platelet, endothelial activation and coagulation activation and fibrinolysis could be established in a large cohort of Fabry disease patients. The existing laboratory abnormalities are more likely related to renal insufficiency rather than to Fabry disease itself.

Renal vascular inflammation induced by Western diet in ApoE-null mice quantified by (19)F NMR of VCAM-1 targeted nanobeacons

We have designed multifunctional nanoparticulate reporter bioprobes capable of targeting vascular cell adhesion molecule 1 (VCAM-1), which is up-regulated in numerous inflammatory processes. These perfluorocarbon-cored nanoparticles emit a unique (19)F magnetic resonance (MR) signature, providing the potential to localize and quantify VCAM-1 expression in early atherosclerosis. Nanoparticle-VCAM-1 targeting specificity was confirmed by in vitro binding and competition studies. ApoE-null and control C57-BL6 mice (n = 6/group), fed a Western diet for 35 weeks, were injected i.v. with targeted or non-targeted nanoparticles. After two hours, kidneys were excised and prepared for analysis. ApoE-null kidneys exhibited increased VCAM-1-targeted nanoparticle content over healthy controls by (19)F MR spectroscopy (36.5+8.8 vs. 9.3+2.2 x 10(8)/g, P < .05), which correlated with increased VCAM-1 staining (2.5 +/- 1.3% vs. 0.9 +/- 0.3%, P < .05); their relative biodistributions were confirmed by fluorescence microscopy and MR imaging. These molecular imaging agents offer new approaches for detection, quantification, and longitudinal evaluation of early inflammation utilising (19)F MR spectroscopy and imaging.

FROM THE CLINICAL EDITOR

Multifunctional nanoparticulate reporter bioprobes capable of targeting vascular cell adhesion molecule 1 (VCAM-1) are reported in this paper. These perfluorocarbon-cored nanoparticles offer new approaches for detection, quantification, and longitudinal evaluation of early inflammation utilising 19F MR spectroscopy and imaging.

Protein Z and natural anticoagulants in children on peritoneal dialysis and hemodialysis

Hemostatic alterations due to abnormalities in the coagulation and fibrinolytic system may occur in dialysis patients. Protein Z (PZ) is a vitamin K-dependent coagulation protein promoting assembly of thrombin with phospholipid vesicles. The aim of this study was to investigate PZ and natural anticoagulants in children on hemodialysis (HD) and peritoneal dialysis (PD). Protein Z, protein C (PC), protein S (PS), antithrombin III (AT III), and fibrinogen levels were studied in 24 PD, 13 HD patients and 23 controls. Plasma PZ levels in patients on HD were significantly higher than those on PD and control group (p = 0.04, p = 0.03). We observed elevated PC, PS and AT III activities in children on PD when compared to controls (p = 0.011, p = 0.003, p < 0.001). In HD patients, only PS activity was increased compared to controls (p = 0.016). PC and PS activities did not differ between PD and HD patients whereas AT III activity was higher in PD patients compared to HD patients (p < 0.001). Normal/high levels of PC, PS and AT III suggest that children on PD or HD treatment do not seem to have an increased risk of thrombogenesis due to reduction of these proteins. Increased PZ levels, however, might contribute to the hemostatic alterations in children on HD treatment along with other well known abnormalities.

Thyroid Function, Endothelium, and Inflammation in Hemodialyzed Patients: Possible Relations?

OBJECTIVE

Renal function affects the thyroid gland in many ways. Disturbances in hemostasis and inflammation are common complications of kidney diseases. Endothelial dysfunction may link these two processes.

DESIGN AND PATIENTS

A cross-sectional study on thyroid hormones in relation to markers of endothelial damage and inflammation in 96 hemodialyzed (HD) patients and 39 healthy volunteers was performed.

SETTING

The study took place in the dialysis unit at a university hospital.

INTERVENTION

Thyroid hormones, markers of endothelial damage (von Willebrand factor, thrombomodulin, intracellular adhesion molecule, and CD146), markers of inflammation (high-sensitivity C-reactive protein, tumor necrosis factor alpha), other hemostatic parameters (thrombin-antithrombin complexes, prothrombin fragments 1 + 2 - F1 + 2, plasmin-antiplasmin complexes, tissue plasminogen activator and its inhibitor, tissue factor pathway inhibitor, and platelet glycoprotein V) were measured using commercially available kits.

RESULTS

Free T3 and total T3 were lower in HD patients compared with controls. Markers of endothelial dysfunction and inflammation were significantly elevated in HD patients compared with controls. In multiple regression analysis T3 was independently related to time on dialyses, albumin, iron, ferritin, C-reactive protein (CRP), and F1 + 2 in HD patients. Free T3 was also independently related to total protein, total calcium, and triglycerides. In patients with CRP less than 6 mg/L in multiple regression analysis the only correlates of T3 were albumin and ferritin, whereas the only correlates of free T3 were albumin and time on dialyses. Multiple regression analysis showed that in HD patients with CRP greater than equal to 6 mg/L predictors of free T3 were CRP, F1 + 2, and dose of erythropoietin. In healthy volunteers T3 was related to tissue factor pathway inhibitor and platelet glycoprotein V was related to thyroid-stimulating hormone.

CONCLUSIONS

We described novel relations between thyroid hormones and markers of endothelial dysfunction and inflammation in HD patients. Thyroid dysfunction is related to time on dialyses, endothelial damage, and inflammatory state, frequently encountered in uremia. Therefore, the relations between thyroid axis and endothelium in HD subjects merit additional studies.

Beneficial effects of aminoguanidine on peritoneal microcirculation and tissue remodelling in a rat model of PD

BACKGROUND

The formation of glucose degradation products (GDPs) and accumulation of advanced glycation end products (AGEs) partly contribute to the bioincompatibility of peritoneal dialysis fluids (PDF). Aminoguanidine (AG) scavenges GDPs and prevents the formation of AGEs.

METHODS

In a peritoneal dialysis (PD) rat model, we evaluated the effects of the addition of AG to the PDF on microcirculation and morphology of the peritoneum, by intravital microscopy and quantitative morphometric analysis.

RESULTS

AG-bicarbonate effectively scavenged different GDPs from PDF. Daily exposure to PDF for 5 weeks resulted in a significant increase in leucocyte rolling in mesenteric venules, which could be reduced for approximately 50% by addition of AG-bicarbonate (P<0.02). Vascular leakage was found in rats treated with PDF/AG-bicarbonate, but not with PDF alone. Evaluation of visceral and parietal peritoneum showed the induction of angiogenesis and fibrosis after PDF instillation. PDF/AG-bicarbonate significantly reduced vessel density in omentum and parietal peritoneum (P<0.04), but not in mesentery. PDF-induced fibrosis was significantly reduced by AG (P<0.02). PDF instillation led to AGE accumulation in mesentery, which was inhibited by supplementation of AG. Since addition of AG-bicarbonate to PDF raised pH from 5.2 to 8.5, a similar experiment was performed with AG-hydrochloride that did not change the fluid acidity. We could reproduce most of the results obtained with AG-bicarbonate; however, AG-hydrochloride induced no microvascular leakage and had a minor effect on angiogenesis.

CONCLUSION

The supplementation of either AG reduced a number of PDF-induced alterations in our model, emphasizing the involvement of GDPs and/or AGEs in the PDF-induced peritoneal injury.

Is there a link between CD146, a novel adhesion molecule and other markers of endothelial dysfunction in nephrotic syndrome and continuous ambulatory peritoneal dialysis?

BACKGROUND

CD146 is a novel cell adhesion molecule localized at the endothelial junction. Its increased plasma levels in chronic renal failure are linked to endothelial dysfunction. Endothelial dysfunction and hemostatic disturbances, a common feature of nephrotic syndrome (NS), mimics a state of protein loosing by peritoneal membrane in patients on chronic ambulatory peritoneal dialyses (CAPD). The aim of the study was to assess CD146 in relation to other markers of endothelial cell injury in patients with NS in comparison to patients on CAPD.

MATERIALS AND METHODS

We studied 45 CAPD patients, 43 patients with nephrotic syndrome and 25 healthy volunteers. Markers of endothelial cell injury: TFPI total, full length, truncated, von Willebrand factor, trombomodulin, P-selectin, E-selectin, ICAM, VCAM and CD146 were assessed using commercially available kits.

RESULTS

All these markers studied except selectins were significantly elevated in patients with NS and CAPD when compared to the healthy volunteers. In CAPD, VCAM, thrombomodulin and CD146 were significantly elevated over NS patients. CD146 correlated significantly with ICAM as well as total and truncated TFPI in CAPD patients. Moreover, total TFPI was positively related to VCAM. CD146 correlated with ICAM in NS, whereas in healthy volunteers CD146 correlated only with TFPI concentration.

CONCLUSIONS

Our studies indicate that in nephrotic patients, as well as in CAPD, there is an evidence of endothelial cell injury. Correlations between CD146 and adhesion molecules and TFPI might further support its use as a endothelial cell function marker.