Post-dialysis Samples Research Articles

Level of high sensitivity troponin I and its correlation with hemodialysis vintage – A pilot study

Background: Renal replacement therapy (RRT) is advised in end-stage renal disease, the last stage of chronic kidney disease (CKD). RRT includes maintenance hemodialysis (MHD)/peritoneal dialysis/renal transplant. The requirement for MHD is annually escalating in India. It is important to note that over 80% of patients receiving MHD have at least one cardiac disease at the time of dialysis initiation, such as ischemic heart disease, congestive cardiac failure, and arrhythmias. Aims and Objectives: The present study aimed to study high-sensitivity cardiac troponin I (hs-cTnI) serum level as a marker of cardiovascular injury in patients receiving MHD. It was an attempt to envisage a correlation between serum hs-cTnI and hemodialysis (HD) vintage (duration since initiation of dialysis till date). Materials and Methods: We enrolled 40 patients. Group 1 included those who had received MHD for ≤24 months, and Group 2 included those who had received MHD for more than 24 months. Results: We found no significant difference between the two groups’ clinical characteristics and demographic features. The pre-and post-HD serum hs-cTnI values of all patients were recorded. The serum hs-cTnI levels were found to be elevated in 34 out of 40 patients’ post-dialysis, and the result was statistically significant (P=0.0001). Conclusion: The present study has encouraging results, with values of hs-cTnI raised in post-dialysis samples; however, the levels did not correlate with HD vintage. Further studies with larger sample sizes and longer follow-ups would provide more detailed information on hs-cTnI’s role as a marker for HD-induced cardiac damage.

Bisphenol A and chlorinated derivatives of bisphenol A assessment in end stage renal disease patients: Impact of dialysis therapy

Patients with end stage kidney disease treated by dialysis (ESKDD) process dialysis sessions to remove molecules usually excreted by kidneys. However, dialysis therapy could also contribute to endocrine disruptors (ED) burden. Indeed, materials like dialyzer filters, ultrapure dialysate and replacement fluid could exposed ESKDD patients to Bisphenol A (BPA) and chlorinated derivatives of BPA (ClxBPAs). Thus, our aim was to compare BPA and ClxBPAs exposure between ESKDD patients, patients with stage 5 chronic kidney disease (CKD5) not dialyzed and healthy volunteers. Then we describe the impact of a single dialysis session, according to dialysis modalities (hemodialysis therapy (HD) versus online hemodiafiltration therapy (HDF)) and materials used with pre-post BPA and ClxBPAs concentrations. The plasma levels of BPA and four ClxBPAs, were assessed for 64 ESKDD patients in pre and post dialysis samples (32 treated by HD and 32 treated by HDF) in 36 CKD5 patients and in 24 healthy volunteers. BPA plasma concentrations were 22.5 times higher for ESKDD patients in pre-dialysis samples versus healthy volunteers (2.208 ± 5.525 ng/mL versus 0.098 ± 0.169 ng/mL) (p < 0.001). BPA plasma concentrations were 16 times higher for CKD5 patients versus healthy volunteers, but it was not significant (1.606 ± 3.230 ng/mL versus 0.098 ± 0.169 ng/mL) (p > 0.05). BPA plasma concentrations for ESKDD patients in pre-dialysis samples were 1.4 times higher versus CKD5 patients (2.208 ± 5.525 ng/mL versus 1.606 ± 3.230 ng/mL) (p < 0.001). For healthy volunteers, ClxBPAs were never detected, or quantified while for CKD5 and ESKDD patients one ClxBPAs at least has been detected or quantified in 14 patients (38.8%) and 24 patients (37.5%), respectively. Dialysis therapy was inefficient to remove BPA either for HD (1.983 ± 6.042 ng/mL in pre-dialysis versus 3.675 ± 8.445 ng/mL in post-dialysis) or HDF (2.434 ± 5.042 ng/mL in pre-dialysis versus 7.462 ± 15.960 ng/mL in post dialysis) regarding pre-post BPA concentrations (p > 0.05). The same result was observed regarding ClxBPA analysis. Presence of polysulfone in dialyzer fibers overexposed ESKDD patients to BPA in pre-dialysis samples with 3.054 ± 6.770 for ESKDD patients treated with a polysulfone dialyzer versus 0.708 ± 0.638 (p = 0.040) for ESKDD patients treated without a polysulfone dialyzer and to BPA in post-dialysis samples with 6.629 ± 13.932 for ESKDD patients treated with a polysulfone dialyzer versus 3.982 ± 11.004 (p = 0.018) for ESKDD patients treated without a polysulfone dialyzer. This work is to our knowledge the first to investigate, the impact of a dialysis session and materials used on BPA and ClxBPAs plasma concentrations and to compare these concentrations to those found in CKD5 patients and in healthy volunteers.

Dynamics of biophysical characteristics of albumin in patients on programmed hemodialysis

Background. One of the components of the metabolome that performs multifaceted functions in homeostasis is blood albumin. The albumin molecule has a pronounced hydrophilicity, due to which it plays an important role in maintaining oncotic blood pressure. Thus, the expansion of knowledge about the interrelationships of traditional biochemical information about the concentration of albumin and the biophysical properties of its derivatives complements the idea of the pharmacological effect of albumin transfusions. THE AIM: to study of the biophysical properties of albumin in patients with chronic kidney disease on programmed hemodialysis.Patients and Methods. The study included 29 patients with chronic renal failure treated with programmed bicarbonate hemodialysis for an average of 110 months. To assess the condition of patients, a complex of laboratory studies was used, including hematological examination on Beckman Coulter analyzers; clinical assessment of nutritional status based on data from the analysis of medical histories; assessment of colloidal osmotic blood pressure by calculation, as well as by direct measurement on a BMT 923 oncometer; measurement of particle size in blood plasma by dynamic light scattering on a Photocor Compact spectrometer- Z. Statistical analysis of the material was performed using the Statistica for Windows v.6.0 software package. The null statistical hypothesis of the absence of differences and connections was rejected at p&lt;0.05. RESULTS. The average correlation coefficient of oncotic pressure was 0.94 for total protein and 0.90 for albumin. Measurement of colloidal osmotic pressure showed a significant increase in pressure in each of the postdialysis samples. The hydrodynamic radius of the albumin peak for the predialysis sample is significantly higher, which may indicate a change in the sorption properties of the albumin surface. CONCLUSION. The calculation of oncotic pressure by the concentration of total protein, as a rule, provides clinical needs, however, with a significant concentration of toxins, clinical situations are possible in which a moderate decrease in the concentration of the "total protein" of the blood is detected, hence the main oncotic component – albumin is noted but there is a development pronounced edematous syndrome due to a significant decrease in oncotic pressure as a result of a conformational change in albumin molecules. In such situations, it is necessary to directly determine the oncotic pressure of the blood. Keywords: albumin, oncotic pressure, hydrodynamic radius, dialysis&gt;˂0.05.Results. The average correlation coefficient of oncotic pressure was 0.94 for total protein and 0.90 for albumin. Measurement of colloidal osmotic pressure showed a significant increase in pressure in each of the postdialysis samples. The hydrodynamic radius of the albumin peak for the predialysis sample is significantly higher, which may indicate a change in the sorption properties of the albumin surface.Conclusion. The calculation of oncotic pressure by the concentration of total protein, as a rule, provides clinical needs, however, with a significant concentration of toxins, clinical situations are possible in which a moderate decrease in the concentration of the "total protein" of the blood is detected, hence the main oncotic component – albumin is noted but there is a development pronounced edematous syndrome due to a significant decrease in oncotic pressure as a result of a conformational change in albumin molecules. In such situations, it is necessary to directly determine the oncotic pressure of the blood.

The Change in tPSA, fPSA and f/tPSA Levels in Men Undergoing Hemodialysis Effect of Hemodialysis on Serum PSA Levels

Purpose: This study aimed to assess the impact of hemodialysis treatment and different dialysis membranes with varying surface areas on serum levels of total prostate-specific antigen (tPSA), free prostate-specific antigen (fPSA), and the fPSA/tPSA ratio in patients undergoing hemodialysis treatment.&#x0D; Material and Methods: The study was conducted at the Central Laboratory of....Hospital in May, June, and July 2020. tPSA, fPSA, and fPSA/tPSA ratios measured in pre-dialysis and post-dialysis samples were determined. Correlation between pre-dialysis and post-dialysis of fPSA and tPSA levels and patients' ultrafiltrates were evaluated. The fPSA, tPSA, and fPSA/tPSA measured in pre-dialysis and post-dialysis samples grouped according to membrane type were compared.&#x0D; Results: The fPSA levels and fPSA/tPSA ratios of pre-dialysis samples were significantly lower than post-dialysis samples. tPSA values were not significantly different in pre-dialysis and post-dialysis samples. According to membrane types, it was found that pre-dialysis and post-dialysis tPSA, fPSA, and fPSA/tPSA were not significantly different. There was a positive correlation between difference in fPSA concentrations measured in pre-dialysis and post-dialysis samples and ultrafiltrate (rho=0.380). A positive correlation was found between difference in tPSA concentrations measured in pre-dialysis and post-dialysis samples and ultrafiltrate (rho=0.562).&#x0D; Conclusion: Post-dialysis fPSA values and fPSA/tPSA ratios were found to be elevated in patients receiving hemodialysis treatment due to hemoconcentration and other potential effects of dialysis. Therefore, interpreting fPSA values and fPSA/tPSA ratios in patients undergoing hemodialysis treatment according to current clinical decision limits may lead to misinterpretation. In this group of patients, the use of tPSA testing is safe as it remains unaffected by dialysis treatment.

MO653: High-Flux Haemodialysis and Haemodiafiltration: A Comparative Study Based on 1-H NMR Serum Metabolic Profile

Abstract BACKGROUND AND AIMS Patients with chronic kidney disease (CKD) accumulate uraemic toxins (UTs). When compared to other conventional dialysis modalities, high volume haemodiafiltration (HDF) improves the removal of medium and low molecular weight UTs. The present study is a post-hoc analysis comparing the metabolomic profile in serum from patients under high flux HD (hf-HD) and HDF in HDFIT, a multicentric randomized controlled trial (RCT). METHOD Random (pre- and post-dialysis) samples from nine patients in a study arm were selected at baseline and at the end of the follow-up. To compare the samples, 26 possibly matching metabolites were identified by a t-test among the four groups using 1-H nuclear magnetic resonance (NMR). To evaluate the comparison between the modalities in a single treatment session, the clearance rates (CRs) of each metabolite were calculated based on pre- and post-dialysis samples. In addition, to evaluate the effect of UTs removal during the trial follow-up period, the pre-dialysis metabolite concentrations both at the baseline and 6 months were compared with the two arms of the study. RESULTS Evaluating the concentrations of the metabolites during the follow-up period for each study arm, it was possible to assess the effects of UTs removal during the study for each modality. The comparison of the intensity of the peaks identified 26 possible metabolites that differentiated hf-HD and HDF in this timeframe. The correlation (see Figure 1a) then suggested that the peak integrals of 16 of these metabolites increased from baseline to 6 months in the hf-HD, but not in the HDF arm. Amongst the metabolites, several are involved in important metabolic pathways, such as the metabolisms of phenylalanine and the biosynthesis of phenylalanine, tyrosine and tryptophan, which both relate to UTs and the development of cardiovascular diseases. The peak integration relative to glycolic acid was significantly higher (P&amp;lt;.05) at 6 months than at baseline (see Figure 1b) in the hf-HD than in the HDF arm, which has been related to an increased number of renal failure and of renal insufficiency cases [1,2], as well as it related to liver damage [3]. CONCLUSION The concentrations of metabolites related both to CKD and associated pathologies were stable in the HDF arm only during the follow-up period, suggesting enhancement of the long-term stability by this method. In the hf-HD long-term follow-up, the relative increase in the glycolic acid peak integration area, which is related to the metabolite concentration, has also previously been linked to an increased number of renal failures and renal insufficiency cases and to liver damages.

Comparative metabolomic study of high-flux hemodialysis and high volume online hemodiafiltration in the removal of uremic toxins using 1H NMR spectroscopy

Uremic toxins (UTs) accumulate in the circulation of patients with chronic kidney disease (CKD). High volume hemodiafiltration (HDF) improves clearance of low and medium molecular weight UTs compared to HD. The present study is a post-hoc analysis comparing the metabolomic profile in serum from patients under high flux HD (hf-HD) and HDF in HDFIT, a multicentric randomized controlled trial (RCTs). Per protocol, serum samples were collected pre- and post- dialysis treatments at randomization (baseline) and at the end of the follow up (6 months) and stored in a biorepository. Random (pre- and post-dialysis) samples from nine patients in study arm were selected at baseline and at the end of the follow up. To compare the samples, 26 possibly matching metabolites were identified by a t-test among the four groups using 1H nuclear magnetic resonance (NMR). To evaluate the comparison between the modalities is a single treatment session, the clearance rates (CRs) of each metabolite were calculated based on pre-dialysis and post-dialysis samples. In addition, to evaluate to effect of UT removal during the trial follow up period, the pre-dialysis metabolite concentrations at the baseline and at 6 months were compared among the two arms of the study. There was no significant difference between in the single session CRs of metabolites when hf-HD and HDF were compared. On the other hand, the comparison between baseline and 6-month (long-term evolution) led to the identification of 16 metabolites that differentiated the hf-HD and the HDF evolutions. Most of these 16 metabolites are involved in several important metabolic pathways, such as metabolism of phenylalanine and biosynthesis of phenylalanine, tyrosine, and tryptophan, which are related to UTs and cardiovascular disease development. Although no difference was observed between hf-HD and HDF samples before and after a single session, concentrations of CKD-relevant metabolites and associated pathologies were stable in the HDF samples, but not in the hf-HD samples, over the six-month period, suggesting that HDF enhances long-term stability.

Effect of haemodialysis on renal profile in chronic renal failure patients at a tertiary care centre

: In chronic renal failure there is a steady and continued decrease in renal clearance or glomerular filtration rate (GFR), which leads to the gathering of urea, creatinine and other waste metabolites in the blood. Haemodialysis is considered as a good therapeutic option in the context of the renal replacement therapies in which different body waste products including urea, creatinine and free water are removed from the blood. In view of that, the present study was conducted to evaluate the effect of haemodialysis on different renal biochemical parameter in CRF patients.The present study was a hospital based study including 84 chronic renal failure patients on haemodialysis attending a tertiary care hospital in Bihar. Blood samples were collected before and four hours after haemodialysis and serum urea, creatinine, uric acid, potassium, sodium and calcium were estimated.Our results revealed that there was significant decrease in the serum level of urea, creatinine, uric acid and potassium in post dialysis samples with p-value (&amp;#60;0.001, 0.001 0.003 and 0.001) respectively when compared to pre dialysis samples, while showed significant increase of sodium and calcium level in post dialysis samples with p-value (&amp;#60;0.004 and 0.005)The Study concludes that, haemodialysis increase serum sodium and calcium level and decrease serum urea, creatinine, uric acid and potassium level.

Determination of unbound fraction of dorzagliatin in human plasma by equilibrium dialysis and LC-MS/MS and its application to a clinical pharmacokinetic study

Dorzagliatin, a novel glucokinase (GK) activator targeting both pancreatic and hepatic GK, is currently in late-stage clinical development for treatment of type 2 diabetes (T2D). For the optimization of dosing regimens to ensure adequate safety and efficacy, it is critical to have a deep understanding of pharmacokinetic (PK) and pharmacodynamic (PD) profiles of the drug in various targeting patient populations, considering the fact that T2D adversely affects a vast patient population who often times also suffer from a wide range of comorbidities including severe liver and/or kidney damage. Since drug efficacy seems to be closely related to unbound drug concentrations at the site of action, therefore, the determination of plasma unbound concentrations/fractions of dorzagliatin is of crucial importance, especially when performing the PK/PD assessment in those special populations. In the current study, a method was developed and validated for determining the unbound fraction (fu) of dorzagliatin in human plasma by using equilibrium dialysis for the separation of the bound and unbound drug, and LC–MS/MS for subsequent quantification. We have successfully addressed two widely recognized challenges for determination of the fu, i.e., the lack of knowledge on the “true fu” and the difficulty in assessing the accuracy and reproducibility of the measurement. Using this method, a 0.2 mL aliquot of human plasma samples were first dialyzed against 0.35 mL of phosphate buffered saline buffer at 37 °C for 5 h in the equilibrium dialysis device to separate the unbound dorzagliatin. Afterwards, post-dialysis samples were extracted by protein precipitation using acetonitrile. Separation of dorzagliatin and potential interferences were achieved using a Gemini C18 column coupled with gradient elution. Subsequent detection was carried out on tandem mass spectrometer operated by multiple reaction monitoring in positive mode using electrospray ionization. The standard curve over the concentration range of 0.125−250 ng/mL exhibits good linearity. The method was fully validated meeting the requirements in current bioanalytical guidance and was successfully applied in a clinical PK study of dorzagliatin in healthy volunteers and patients with renal function impairment. Method reproducibility was demonstrated in incurred sample reanalysis. With demonstrated accuracy, stability and reproducibility, reliable analytical results were obtained from clinical samples for PK/PD interpretation, providing valuable insight for the development of dorzagliatin.

The effect of high-flux hemodialysis and post-dilution hemodiafiltration on platelet closure time in patients with end stage renal disease.

We aimed to compare prospectively the effect of high-flux hemodialysis and post-dilution hemodiafiltration on platelets. Twenty-two hemodialysis patients were treated with one high-flux hemodialysis and one post-dilution hemodiafiltration procedure. PFA-100 closure times (collagen/epinephrine-CEPI and collagen/adenosine diphosphate-CADP) were measured before and after the procedure, as well as platelet count, hemoglobin, hematocrit, and red blood cell count. All pre-dialysis and post-dialysis samples were taken from the afferent line. The platelet count after vs. before hemodialysis did not change significantly (229.3 ± 55.0 x109 /L vs. 233.6 ± 55.8 × 109 /L; P = 0.269), but was significantly lower after post-dilution hemodiafiltration (215.5 ± 51.7 × 109 /L vs. 245.3 ± 59.9 × 109 /L; P < 0.0001). CEPI after vs. before hemodialysis was not significantly prolonged (192.9 ± 60.8 s vs. 173.4 ± 52.5 s; P = 0.147), and the same applied to CADP (143.6 ± 40.3 s vs. 142.6 ± 38.4 s; P = 0.897). CEPI after vs. before post-dilution hemodiafiltration was significantly prolonged (268.3 ± 41.3 s vs. 176.4 ± 54.0 s; P < 0.0001) as was CADP (221.0 ± 53.9 s vs.133.9 ± 31.1 s; P < 0.0001). Only after post-dilution hemodiafiltration, we found a lower platelet count and prolonged platelet closure times.

New Insights into the Pathogenesis of Intradialytic Hypertension

Background: Intradialytic hypertension is identified as an independent predictor of adverse clinical outcome in hemodialysis patients. Little is known about its pathophysiological mechanism. Objective: The aim of this study is to provide new insights into the mechanisms underlying this arterial pressure dysregulation. Methods: 62 subjects on chronic hemodialysis were included in this study. Blood pressure was monitored before, during and following each dialysis session for a 3-month period. Pre- and post-dialysis blood samples were drawn from all the subjects to perform immunoassays, monocyte extractions and western blot analyses. Results: Blood pressure values separated the subjects with in two groups: normal blood pressure (n=53) and intradialytic hypertension (n=9) groups. Renin, angiotensin converting enzyme I and aldosterone plasma concentrations significantly diverged between the groups. Vascular endothelial nitric oxide assessment revealed significantly lower plasma L-citrulline and angiotensin-converting enzyme II in post-dialysis intradialytic hypertensive patients, along with high endothelin I and asymmetric dimethylarginine concentrations. Plasma collectrin levels were significantly higher in pre and post-dialysis intradialytic hypertensive group compared to a normal blood pressure group. Post-dialysis interleukin 6 was significantly higher in intradialytic hypertensive group compared to normal blood pressure group. Finally, pre-dialysis intradialytic hypertension was associated with significantly higher circulating vascular endothelial growth factor C with monocytic up-regulation of vascular endothelial growth factor C/tonicity-responsive enhancer binding protein expression. Conclusion: Impairment of vascular endothelial nitric oxide key regulatory elements, as well as monocytic vascular endothelial growth factor C seems to be more prevalent in intradialytic hypertension. These clues could pinpoint novel therapeutic interventions in intradialytic hypertension management.

Impact of post-dialysis calcium level on ex vivo rat aortic wall calcification.

ObjectivesVascular calcification is a frequent complication in chronic haemodialysis patients and is associated with adverse outcomes. Serum calcium and phosphate levels and imbalances in calcification regulators are thought to contribute to the process. In this regard, the dialysate calcium concentration is a modifiable tool for modulating the risk of vascular calcification. We explored pre- and post-dialysis phosphate and calcium concentrations in stable chronic haemodialysis patients treated by dialysis with the KDIGO-suggested 1.5 mmol/L calcium dialysate to investigate the effects on ex vivo calcification of rat aortic rings.Approach and resultsAt the end of haemodialysis, mean serum calcium levels were increased in 88% of paired pre-/post-dialysis samples, while mean serum phosphate and parathyroid hormone levels were decreased. Rat aortic ring cultures grown at the same calcium and phosphate concentrations revealed that pre- and post-dialysis resulted in a similar degree of calcification. By contrast, haemodialysis with unchanged serum calcium resulted in a 5-fold reduction in calcium deposition.ConclusionDialysis with the widely prescribed 1.5 mmol/L calcium dose results in persistent high serum calcification potential in a sizable proportion of patients, driven by increased post-dialysis calcium concentration. This could potentially be mitigated by individualising dialysate calcium dosage based on pre-dialysis serum calcium levels.

Mechanisms Involved in Hypersensitivity Reactions to Polysulfone Hemodialysis Membranes.

Several cases of patients with anaphylactic or systemic hypersensitivity reactions to polysulfone (PS) hemodialysis (HD) membranes and tolerance to cellulose triacetate (CTA) membranes have recently been reported. To investigate the mechanisms involved in PS hypersensitivity, basophil, T cell, and complement activation were analyzed in acute-phase samples from two patients with systemic reactions to PS-based membranes. Basophil and T cell activation, as well as higher serum tryptase levels were detected in acute-phase samples compared with basal levels. Complement levels (C3 and C4) were decreased in acute-phase samples from PS-allergic patients to a higher extent than in samples from control donors taken at the same time points, indicating complement activation during the acute reactions. An experimental external circuit was established on pediatric membranes after rinsing with low or high priming volumes of saline solution, to analyze basophils, T cells, and complement activation in blood samples from 10 PS-allergic and 8 nonallergic HD patients upon contact with PS-based or CTA membranes. Predialysis and postdialysis samples were collected. Basophils from PS-allergic patients exhibited increased degranulation, and T cells showed significantly increased activation after contact with PS-based membranes primed with low volumes of saline. No activation was detected in leukocytes from nonallergic patients under the same experimental conditions. Membrane priming with high volumes of saline abrogated activation of basophils and T cells. However, basophils from allergic donors showed significantly higher responses to Fcεc stimulation after contact with PS membranes. Basophil degranulation and elevated serum tryptase levels in allergic patients during acute reactions support the systemic activation of mast cells and basophils during hypersensitivity reactions to PS-based membranes. A leachable component of the membranes might be responsible for cell activation in some patients.

Effects of Arterial Needle Placement in Arteriovenous Fistula on Dialysis Adequacy of End-Stage Renal Disease Patients Undergoing Maintenance Hemodialysis

Objective: The arterial needle placement in arteriovenous fistula (AVF) can either be antegrade (in the direction of blood flow or pointing towards the heart) or retrograde (against the direction of blood flow) while venous needle placement should always be in the same direction as the blood flow. This study determined the effects of arterial needle placement in the arteriovenous fistula on dialysis adequacy of End-Stage Renal Disease (ESRD) patients undergoing maintenance hemodialysis in United Candelaria Doctors Hospital - Nephro Synergies Inc. (UCDHNSI) Hemodialysis Center. Methods: A randomized controlled trial design was used in the study. A total of 20 non-diabetic, non-cardiac patients on maintenance hemodialysis for more than 6 months were randomized either to the intervention group (patients’ AVF were cannulated in a retrograde manner) or the control group (patients’ AVF were cannulated in an antegrade manner). Urea reduction ratio (URR) and Kt/V as well as access recirculation percentage were used to determine dialysis adequacy. Pre-dialysis, in the first 30 minutes of dialysis initiation and post-dialysis blood samples were obtained in each patient in 6 succeeding hemodialysis considering dialyzer reuse up to fifth reuse. Means were compared by independent t-test. Results: The findings of the study revealed that the mean URR and Kt/V of the subjects cannulated in retrograde manner and antegrade manner were 69.35% and 1.45, and 74.65% and 1.70, respectively. The mean access recirculation percentage of the subjects was 4.65% in the intervention group and 3.02% in the control group. There was a significant difference on URR and Kt/V of the subjects using retrograde and antegrade arterial needle placement in 6 succeeding hemodialysis sessions. There was no significant difference on access recirculation percentage of the subjects using retrograde and antegrade arterial needle placement in 6 succeeding hemodialysis sessions. Conclusions: Antegrade arterial needle placement provides more adequate hemodialysis than retrograde arterial needle placement in terms of URR and Kt/V values among non-diabetic, non-cardiac patients undergoing maintenance hemodialysis in 6 succeeding hemodialysis sessions. The directions of the arterial needle either retrograde and antegrade did not have significant effects on access recirculation.

Sclerostin levels in uremic patients: a link between bone and vascular disease

Sclerostin is a marker of low-turnover bone disease in end stage renal disease patients. The aim of this study was to evaluate serum sclerostin in uremic patients, analyzing its behavior during a single hemodialysis session. Twenty-one adult patients on intermittent hemodialysis treatment were enrolled. Acetate Free Bio-filtration (AFB) was the technique employed. Uremic patients were characterized by higher levels of serum sclerostin when compared with values observed in healthy subjects. Sclerostin assessed in pre-dialysis samples was 1.4 ± 1.02 ng/mL, whereas, in post dialysis samples, a reduction of sclerostin values was observed (0.8 ± 0.6 ng/mL; p: 0.008). Sclerostin correlated with parameters of dialysis adequacy, such as creatinine levels and Kt/V values, and it was significantly associated with atherosclerotic disease. Receiver operating characteristics analysis revealed a good diagnostic profile in identifying atherosclerotic disease. Sclerostin, a full dialyzable substance during AFB dialysis, is closely associated with atherosclerotic disease. Its reduction obtained through AFB could represent a defensive mechanism, improving vascular disease and renal osteodystrophy.

Variations in the Circulating Heparin Levels During Maintenance Hemodialysis in Patients With End-Stage Renal Disease

Unfractionated heparin has remained the anticoagulant of choice in patients undergoing hemodialysis. However, wide variations in the heparinization responses have been observed in patients anticoagulated with this drug. The purpose of this investigation was to measure circulating heparin levels in patients with end-stage renal disease (ESRD) prior to and after maintenance hemodialysis. This study included 119 patients with ESRD undergoing maintenance hemodialysis who received heparin during dialysis. Citrated blood samples were collected prior to and immediately after the dialysis session and analyzed utilizing clot-based methods such as activated partial thromboplastin time (APTT), Heptest, and prothrombinase-induced clotting time (PiCT). Circulating anti-Xa levels, antithrombin III levels, and thrombin generation (TG) were also measured. The circulating heparin levels ranged from 0 to 1.08 IU/mL with a mean of 0.07 ± 0.11 for the APTT and a range of 0 to 1.98 for the Heptest with a mean of 0.09 ± 0.26 U/mL. There was no significant difference in circulating levels of heparin between pre- and post-hemodialysis samples using APTT, Heptest, and PiCT, whereas the TG and anti-Xa tests showed a statistically significant P value <0.05 when comparing the 2 groups. The presence of detectable levels of heparin in the predialysis plasma samples for almost two-thirds (87 of 119) of the patients suggests that residual heparin circulates in these patients for a longer period of time. In all, 5% of postdialysis samples, 6 of 119, contained >0.25 U/mL of heparin, which may be related to a central catheter vascular access flushed with heparin. These findings suggest that patients on maintenance hemodialysis may accumulate a detectable amount of heparin due to the decreased renal clearance.

Variations in the Circulating Heparin Levels During Maintenance Hemodialysis in End Stage Renal Disease Patients

Abstract 3412 Introduction:Unfractionated heparin has remained the anticoagulant of choice for hemodialysis patients. The anticoagulation facilitates blood flow through the dialysis circuit and assures the patency of the dialysis membrane. Wide variations in the heparinization responses have been observed in patients undergoing this procedure. The purpose of this investigation was to measure circulating heparin levels in patients prior to and after hemodialysis. Methods:This study included 119 ESRD patients undergoing maintenance hemodialysis after appropriate IRB approval and patient consent. For the 3–4 hour hemodialysis duration, a heparin loading dose of 1000 Units followed by two additional dosages of 500 Units/hour were administered. Citrated blood samples were collected prior to and immediately after the dialysis session. The blood samples were centrifuged for 15 minutes at 3000 g at 4°C and platelet poor plasma (PPP) was extracted.Citrated plasma was frozen at −70°C and analyzed utilizing such clot based methods as Activated Partial Thromboplastin Time (APTT), Heptest and Prothrombinase Induced Clotting Time (PiCT). Circulating Anti-Xa levels were measured using a chromogenic substrate method. Thromboplastin induced thrombin generation was also measured using a fluorogenic substrate method, Thrombin Generation Assay (TGA). The Antithrombin (AT) levels in each of these patients were also measured using a functional assay. The circulating levels of heparin were determined using a calibration curve constructed from the heparin used in the dialysis unit. Results were computed for the individual tests and heparin concentrations were obtained using the assay based calibration procedures. Results:In the clot based assays such as APTT and Heptest, no significant differences between pre and post plasma samples were noted. The circulating levels of heparin were from 0 to 1.08 U/ml with a mean of 0.07 ± 0.11 for the APTT and a range of 0 to 1.98 for the Heptest with a mean of 0.09 ± 0.26 U/ml. In the PiCT test the range was from 14.0 to 300 seconds for the pre dialysis samples with a mean of 32.0 ± 38.2, whereas for the post samples the range was from 15.2 to 110 with a mean of 29.6 ± 14.0. For the Anti-Xa levels the % inhibition for the two groups was similar. The circulating Anti-Xa levels in the pre dialysis samples ranged from 0 to 0.77 with a mean of 0.10 ± 0.14, whereas the post level ranged from 0 to 0.51 with a mean of 0.13 ± 0.11. For the thrombin generation, the % inhibition levels ranged from 0 to 100% pre dialysis with a mean of 34.2 ± 34% and ranged 0 to 100% post dialysis with a mean of 44.5 ± 34.4%. The Antithrombin levels ranged from 28 to 130% with a mean of 86.6 ± 19.5% in the pre dialysis samples.There was no significant difference between pre and post dialysis samples using APTT, Heptest and PiCT, whereas the Thrombin generation and Anti-Xa resulted in a statistically significant p value < 0.05 when comparing the two groups. Conclusion:Wide variations in circulating heparin levels are noted in maintenance hemodialysis patients at pre dialysis and post dialysis time periods. Some patients exhibit higher levels of heparin due to a vascular access flush. These results also suggest that the use of heparin in maintenance hemodialysis patients in repeated regimen results in a steady state hypocoagulation as evidenced by the inhibition of thrombin generation, circulating Anti-Xa level and the prolongation of various clotting times. Disclosures:No relevant conflicts of interest to declare.

Increased oxidized-LDL levels and arylesterase activity/HDL ratio in ESRD patients treated with hemodialysis

Investigations, in which oxidized-low density lipoprotein (ox-LDL), serum paraoxonase (PON1) and homocysteine (Hcy) are considered together as important agents involved in the development of oxidative and atherogenic events in non-diabetic hemodialysis (HD) population, are limited. This case-control study was designed to evaluate these parameters in the patients and control subjects and to determine the correlations among the factors. Forty-nine age- and sex- matched subjects, including 28 non-diabetic HD patients (paired pre-and post-dialysis samples) and 21 control subjects, were enrolled. Ox-LDL and Hcy levels were measured with ELISA and EIA methods, respectively. Arylesterase activity of PON1 was measured by spectrophotometric assay. Compared with the control group, ox-LDL levels were significantly increased both before (p=0.001) and after HD (p=0.036). Arylesterase activity-to-HDL ratio in HD patients was significantly higher than control subjects (p=0.003). Homocysteine levels in the ESRD patients were higher than control subjects both in pre-dialysis and post-dialysis. There was a significant positive correlation (r= 0.25, p= 0.026) between ox-LDL and homocysteine in samples obtained before HD. Logistic regression analysis revealed ox-LDL levels (OR=3.02, p < 0.001) and arylesterase activity/HDL ratio (OR=2.43, p=0.01) to be associated with the increased risk of ESRD. Ox-LDL levels and arylesterase activity/HDL ratio indicated the strongest association with ESRD risk. These factors, especially ox-LDL as an indicator of oxidative stress, may be biomarkers in evaluating the status of non-diabetic ESRD patients. Because of the pathogenic relationship between ox-LDL and homocysteine as nontraditional risk factors of atherosclerosis, therapeutic strategies adopted to reduce them may be useful in decrease of high prevalence of cardiovascular mortality in dialysis patients. In addition, measurement of PON1 activity to HDL ratio is possibly a more valuable biomarker than arylesterase activity alone in non-diabetic ESRD.

Endogenous factors modified by hemodialysis may interfere with the accuracy of blood glucose‐measuring device

In Japan, self-monitoring of blood glucose (SMBG) devices are widely used both at home and in hospitals, but many analytical errors and safety concerns have been reported about the SMBG devices used in hospitals. Analytical performances of StatStrip (Nova Biomedical Corporation, MA, USA), a new point-of-care testing device and Glutest (Sanwa Chemical, Aichi, Japan), a routinely used SMBG device were compared in glucose measurement of pre- and postdialysis blood samples and we evaluated which factors in blood modified by hemodialysis affect accuracy of these devices. Subjects in this study were 44 hemodialysis patients. Blood samples were obtained from patients just before and just after the hemodialysis. Blood glucose concentrations of samples were measured by StatStrip and Glutest. Hematocrit and plasma concentrations of electrolytes, metabolites, etc. of the samples were measured in the central laboratory. StatStrip showed no difference between pre- and postdialysis blood samples and showed very little bias from reference method. On the other hand, Glutest showed difference between pre- and postdialysis samples. Although there is no problem in the data of predialysis blood samples by Glutest, however, these of the postdialysis blood samples by Glutest were >10% less than reference method. Factors in blood modified by hemodialysis such as hematocrit, uric acid, albumin, potassium, and calcium affected glucose readings by Glutest. Glucose readings by Glutest of samples from hemodialysis patients were affected by hematocrit and several factors, which were modified by hemodialysis. StatStrip is considered as a better device in dialysis hospitals.

A New Ethical Dilemma For Hemodialysis Patients : Exposure To Diethyl Hexyl Phthalate

Patients undergoing hemodialysis are exposed to medical devices containing di-ethylhexyl phthalate(DEHP). There is an ongoing discussion about the risks of DEHP exposure for the general population aswell as for specific subgroups in various medical settings. Due to the widespread use of DEHP in polyvinylchloride (PVC) medical devices and in life, this work is an essential step in such a way that the exposureamount of DEHP would be precisely determined in patients undergoing regular hemodialysis in orderto evaluate its significance as an integral part of the assessment of the risk of DEHP to human liver.Thirty subjects were involved in this work. Ten of them were healthy volunteers (n=10) as a controlgroup and twenty patients with end stage renal disease (ESRD) on regular hemodialysis (n=20). Twosamples were taken from all subjects, one prior to and one after the dialysis session, for measuring theserum levels of: alanine transaminase, aspartate transaminase and albumin, and the estimation of DEHPserum level by using high performance liquid chromatography (HPLC). Significant increases (p<0.001)were detected in DEHP mean serum levels between postdialysis samples and control samples on one side,and predialysis samples on the other side. There is a continuous exposure to DEHP in hemodialysis patients,where they would be considered of the target vulnerable groups continuously exposed to DEHP inhigh amounts. The shift towards safer PVC-free or DEHP-free alternatives should be evaluated and encouraged.

Effects of end-stage renal disease and haemodialysis on dendritic cell subsets and basal and LPS-stimulated cytokine production

Although bacterial infections have dramatically declined as a cause of death in the general population, they remain a major cause of mortality in patients with end-stage renal disease (ESRD). Moreover, the response to vaccination is profoundly impaired in this population. Dendritic cells (DC) are the major antigen-presenting cells that bridge the innate and adaptive immune responses. Activation of DC by pathogens results in secretion of inflammatory cytokines and up-regulation of co-stimulatory molecules. The activated DC prime naïve T and B cells to the captured antigens. Using flow cytometry, the number and phenotype of circulating DC [myeloid DC (mDC) and plasmacytoid DC (pDC)] were quantified in pre- and post-dialysis blood samples from 20 ESRD patients maintained on haemodialysis. Ten normal individuals served as controls. In addition, the level of DC activation and their response to lipopolysaccharide (LPS) stimulation were determined by assessing expression of co-stimulatory molecule, CD86, and antigen-presenting molecule, HLA-DR, as well as production of TNFalpha, IFNalpha and IL-6. Compared to the control group, the circulating dendritic cell count was significantly reduced in the ESRD patients before dialysis and declined further after dialysis. The reduction in pDC numbers was more striking than mDC. The magnitude of the LPS-induced up-regulation of CD86 was comparable among the study groups as well as pre- and post-dialysis samples. However, LPS-induced TNFalpha production was significantly reduced in the post-dialysis samples with no significant difference in IL-6 and IFNalpha productions among the study groups and in pre- and post-dialysis samples. ESRD results in significant DC depletion which is largely due to diminished plasmacytoid DC subset. Haemodialysis procedure intensifies DC depletion and impairs LPS-induced TNFalpha production.