Uremic Toxins Induce THP-1 Monocyte Endothelial Adhesion and Migration through Specific miRNA Expression.

Atherosclerosis is initiated by the activation of endothelial cells that allows monocyte adhesion and transmigration through the vascular wall. The accumulation of uremic toxins such as indoxyl sulphate (IS) and p-cresol (PC) has been associated with atherosclerosis. Currently, miRNAs play a crucial role in the regulation of monocyte activation, adhesion, and trans-endothelial migration. The aim of the present study is to evaluate the effect of IS and PC on monocyte adhesion and migration processes in monocytes co-cultured with endothelial cells as well as to determine the underlying mechanisms. The incubation of HUVECs and THP-1 cells with both IS and PC toxins resulted in an increased migratory capacity of THP-1 cells. Furthermore, the exposure of THP-1 cells to both uremic toxins resulted in the upregulation of BMP-2 and miRNAs-126-3p, -146b-5p, and -223-3p, as well as the activation of nuclear factor kappa B (NF-κB) and a decrease in its inhibitor IĸB. Uremic toxins, such as IS and PC, enhance the migratory and adhesion capacity of THP-1 cells to the vascular endothelium. These toxins, particularly PC, contribute significantly to uremia-associated vascular disease by increasing in THP-1 cells the expression of BMP-2, NF-κB, and key miRNAs associated with the development of atherosclerotic vascular diseases.

The direct effect of fibroblast growth factor 23 on vascular smooth muscle cell phenotype and function.

BACKGROUND: In chronic kidney disease (CKD) patients, increased levels of fibroblast growth factor 23 (FGF23) are associated with cardiovascular mortality. The relationship between FGF23 and heart hypertrophy has been documented, however, it is not known whether FGF23 has an effect on vasculature. Vascular smooth muscle cells VSMCs may exhibit different phenotypes; our hypothesis is that FGF23 favours a switch from a contractile to synthetic phenotype that may cause vascular dysfunction. Our objective was to determine whether FGF23 may directly control a change in VSMC phenotype. METHODS: This study includes in vitro, in vivo and ex vivo experiments and evaluation of patients with CKD stages 2-3 studying a relationship between FGF23 and vascular dysfunction. RESULTS: In vitro studies show that high levels of FGF23, by acting on its specific receptor FGFR1 and Erk1/2, causes a change in the phenotype of VSMCs from contractile to synthetic. This change is mediated by a downregulation of miR-221/222, which augments the expression of MAP3K2 and PAK1. miR-221/222 transfections recovered the contractile phenotype of VSMCs. Infusion of recombinant FGF23 to rats increased vascular wall thickness, with VSMCs showing a synthetic phenotype with a reduction of miR-221 expression. Ex-vivo studies on aortic rings demonstrate also that high FGF23 increases arterial stiffening. In CKD 2-3 patients, elevation of FGF23 was associated with increased pulse wave velocity and reduced plasma levels of miR-221/222. CONCLUSION: In VSMCs, high levels of FGF23, through the downregulation of miR-221/222, causes a change to a synthetic phenotype. This change in VSMCs increases arterial stiffening and impairs vascular function, which might ultimately worsen cardiovascular disease.

Passage Number-Induced Replicative Senescence Modulates the Endothelial Cell Response to Protein-Bound Uremic Toxins.

Endothelial aging may be induced early in pathological situations. The uremic toxins indoxyl sulfate (IS) and p-cresol (PC) accumulate in the plasma of chronic kidney disease (CKD) patients, causing accelerated endothelial aging, increased cardiovascular events and mortality. However, the mechanisms by which uremic toxins exert their deleterious effects on endothelial aging are not yet fully known. Thus, the aim of the present study is to determine the effects of IS and PC on endothelial damage and early senescence in cultured human umbilical vein endothelial cells (HUVECs). Hence, we establish an in vitro model of endothelial damage mediated by different passages of HUVECs and stimulated with different concentrations of IS and PC to evaluate functional effects on the vascular endothelium. We observe that cell passage-induced senescence is associated with apoptosis, ROS production and decreased endothelial proliferative capacity. Similarly, we observe that IS and PC cause premature aging in a dose-dependent manner, altering HUVECs' regenerative capacity, and decreasing their cell migration and potential to form vascular structures in vitro. In conclusion, IS and PC cause accelerated aging in HUVECs, thus contributing to endothelial dysfunction associated with CKD progression.

Predicting mortality in hemodialysis patients using machine learning analysis.

BACKGROUND: Besides the classic logistic regression analysis, non-parametric methods based on machine learning techniques such as random forest are presently used to generate predictive models. The aim of this study was to evaluate random forest mortality prediction models in haemodialysis patients. METHODS: Data were acquired from incident haemodialysis patients between 1995 and 2015. Prediction of mortality at 6 months, 1 year and 2 years of haemodialysis was calculated using random forest and the accuracy was compared with logistic regression. Baseline data were constructed with the information obtained during the initial period of regular haemodialysis. Aiming to increase accuracy concerning baseline information of each patient, the period of time used to collect data was set at 30, 60 and 90 days after the first haemodialysis session. RESULTS: There were 1571 incident haemodialysis patients included. The mean age was 62.3 years and the average Charlson comorbidity index was 5.99. The mortality prediction models obtained by random forest appear to be adequate in terms of accuracy [area under the curve (AUC) 0.68-0.73] and superior to logistic regression models (ΔAUC 0.007-0.046). Results indicate that both random forest and logistic regression develop mortality prediction models using different variables. CONCLUSIONS: Random forest is an adequate method, and superior to logistic regression, to generate mortality prediction models in haemodialysis patients.

Assessment of Inorganic Phosphate Intake by the Measurement of the Phosphate/Urea Nitrogen Ratio in Urine.

In chronic kidney disease (CKD) patients, it would be desirable to reduce the intake of inorganic phosphate (P) rather than limit the intake of P contained in proteins. Urinary excretion of P should reflect intestinal absorption of P(inorganic plus protein-derived). The aim of the present study is to determine whether the ratio of urinary P to urinary urea nitrogen (P/UUN ratio) helps identify patients with a high intake of inorganic P.A cross-sectional study was performed in 71 patients affected by metabolic syndrome with CKD (stages 2-3) with normal serum P concentration. A 3-day dietary survey was performed to estimate the average daily amount and the source of P ingested. The daily intake ofPwas1086.5 ± 361.3mg/day; 64% contained in animal proteins, 22% in vegetable proteins, and 14% as inorganic P. The total amount of P ingested did not correlate with daily phosphaturia, but it did correlate with the P/UUN ratio (p < 0.018). Patients with the highest tertile of the P/UUN ratio >71.1 mg/g presented more abundant inorganic P intake (p < 0.038).The P/UUN ratio is suggested to be a marker of inorganic P intake. This finding might be useful in clinical practices to identify the source of dietary P and to make personalized dietary recommendations directed to reduce inorganic P intake.

Inflammation, Senescence and MicroRNAs in Chronic Kidney Disease.

BACKGROUND: Patients with chronic kidney disease (CKD) show a chronic microinflammatory state that promotes premature aging of the vascular system. Currently, there is a growth interest in the search of novel biomarkers related to vascular aging to identify CKD patients at risk to develop cardiovascular complications. METHODS: Forty-five CKD patients were divided into three groups according to CKD-stages [predialysis (CKD4-5), hemodialysis (HD) and kidney transplantation (KT)]. In all these patients, we evaluated the quantitative changes in microRNAs (miRNAs), CD14+C16++ monocytes number, and microvesicles (MV) concentration [both total MV, and monocytes derived MV (CD14+Annexin V+CD16+)]. To understand the molecular mechanism involved in senescence and osteogenic transdifferentation of vascular smooth muscle cells (VSMC), these cells were stimulated with MV isolated from THP-1 monocytes treated with uremic toxins (txMV). RESULTS: A miRNA array was used to investigate serum miRNAs profile in CKD patients. Reduced expression levels of miRNAs-126-3p, -191-5p and -223-3p were observed in CKD4-5 and HD patients as compared to KT. This down-regulation disappeared after KT, even when lower glomerular filtration rates (eGFR) persisted. Moreover, HD patients had higher percentage of proinflammatory monocytes (CD14+CD16++) and MV derived of proinflammatory monocytes (CD14+Annexin V+CD16+) than the other groups. In vitro studies showed increased expression of osteogenic markers (BMP2 and miRNA-223-3p), expression of cyclin D1, ß-galactosidase activity and VSMC size in those cells treated with txMV. CONCLUSION: CKD patients present a specific circulating miRNAs expression profile associated with the microinflammatory state. Furthermore, microvesicles generated by monocytes treated with uremic toxins induce early senescence and osteogenic markers (BMP2 and miRNA-223-3p) in VSMC.

Role of endothelial microvesicles released by p-cresol on endothelial dysfunction.

Protein bound uremic toxins, such as p-cresol, cannot be effectively removed by conventional dialysis techniques and are accumulated in plasma, thus contributing to progression of both chronic kidney disease (CKD) and cardiovascular disease (CVD). Pathological effects of uremic toxins include activation of inflammatory response, endothelial dysfunction and release of endothelial microvesicles. To date, the role of p-cresol in endothelial microvesicles formation has not been analyzed. The aim of the present study was evaluate the effects of endothelial microvesicles released by p-cresol (PcEMV) on endothelial dysfunction. An in vitro model of endothelial damage mediated by p-cresol was proposed to evaluate the functional effect of PcEMV on the endothelial repair process carried out by endothelial cells and microRNA (miRNA) that could be involved in this process. We observed that p-cresol induced a greater release of microvesicles in endothelial cells. These microvesicles altered regenerative capacity of endothelial cells, decreasing their capacity for cell migration and their potential to form vascular structures in vitro. Moreover, we observed increased cellular senescence and a deregulation of miRNA-146b-5p and miRNA-223-3p expression in endothelial cells treated with endothelial microvesicles released by p-cresol. In summary our data show that microvesicles generated in endothelial cells treated with p-cresol (PcEMV) interfere with the endothelial repair process by decreasing the migratory capacity, the ability to form new vessels and increasing the senescence of mature endothelial cells. These alterations could be mediated by the upregulation of miRNA-146b-5p and miRNA-223-3p.

Hemodiafiltration with ultrafiltrate regeneration reduces free light chains without albumin loss in multiple myeloma patients.

BACKGROUND: Acute kidney injury (AKI) occurs in 12-20% of multiple myeloma (MM) patients. Several studies have shown a reduction of free light chains (FLC) using hemodialysis with High-Cut-Off membranes. However, this technique entails albumin loss. Hemodiafiltration with ultrafiltrate regeneration is a technique that includes a process of adsorption. The aim of this study was to evaluate the effectiveness of hemodiafiltration with ultrafiltrate regeneration in reducing FLC levels without causing albumin loss. METHODS: This is an observational study (2012 to 2018) including nine patients with MM (5 kappa, 4 lambda) and AKI. All patients were treated with chemotherapy and hemodiafiltration with ultrafiltrate regeneration. Blood Samples (pre and post-dialysis) and ultrafiltrate were collected pre and post-resin at 5 min after initiation of the session and 5 min before the end of the procedure. RESULTS: The serum levels of kappa and lambda were reduced by a 57.6 ± 10% and 33.5 ± 25% respectively. Serum albumin concentration remained unchanged after the procedure. In the ultrafiltrate, the mean FLC reduction ratio shortly after initiation of the dialysis procedure was: 99.2 and 97.06% for kappa and lambda respectively, and only 0.7% for albumin; and at the end of the session the percent reduction was: 63.7 and 33.62% for kappa and lambda respectively, and 0.015% for albumin. Patients clinical outcome was: 33.3% recovered renal function, 22.2% died during the first year and 44.4% required maintenance dialysis. CONCLUSIONS: Hemodiafiltration with ultrafiltrate regeneration reduces FLC levels without producing a significant loss of albumin; and, FLC removal is maintained throughout the session. Therefore, hemodiafiltration with ultrafiltrate regeneration may be considered an effective adjunctive therapy in patients with MM.

Phosphate control in reducing FGF23 levels in hemodialysis patients.

BACKGROUND: In hemodialysis patients, high levels of Fibroblast Growth Factor 23 (FGF23) predict mortality. Our study was designed to test whether the control of serum phosphate is associated with a reduction in serum FGF23 levels. Additionally other variables with a potential effect on FGF23 levels were evaluated. MATERIAL AND METHODS: The effect of sustained (40-weeks) control of serum phosphate on FGF23 levels (intact and c-terminal) was evaluated in 21 stable hemodialysis patients that were not receiving calcimimetics or active vitamin D. Patients received non-calcium phosphate binders to maintain serum phosphate below 4.5 mg/dl. In an additional analysis, values of intact-FGF23 (iFGF23) and c-terminal FGF23 (cFGF23) from 150 hemodialysis patients were correlated with parameters of mineral metabolism and inflammation. Linear mixed models and linear regression were performed to evaluate longitudinal trajectories of variables and the association between FGF23 and the other variables examined. RESULTS: During the 40-week treatment, 12 of 21 patients achieved the target of serum phosphate <4.5 mg/dl. In these 12 patients, iFGF23 decreased to less than half whereas cFGF23 did not reduce significantly. In patients with serum phosphate >4.5 mg, iFGF23 and cFGF23 increased two and four-fold respectively as compared with baseline. Furthermore, changes in serum phosphate correlated with changes in C-reactive protein (hs-CRP). In our 150 hemodialysis patients, those in the higher tertile of serum phosphate also showed increased hs-CRP, iPTH, iFGF23 and cFGF23. Multiple regression analysis revealed that iFGF23 levels directly correlated with both serum phosphate and calcium, whereas cFGF23 correlated with serum phosphate and hs-CRP but not with calcium. CONCLUSIONS: The control of serum phosphate reduced iFGF23. This reduction was also associated with a decreased in inflammatory parameters. Considering the entire cohort of hemodialysis patients, iFGF23 levels correlated directly with serum phosphate levels and also correlated inversely with serum calcium concentration. The levels of cFGF23 were closely related to serum phosphate and parameters of inflammation.

Hemodiafiltration With Endogenous Reinfusion Improved Microinflammation and Endothelial Damage Compared With Online-Hemodiafiltration: A Hypothesis Generating Study.

Hemodiafiltration with endogenous reinfusion (HFR) after ultrafiltrate passage through a resin cartridge combines adsorption, convection, and diffusion. Our prospective single-center crossover study compared HFR and online-hemodiafiltration (OLHDF) effects on two uremic toxins and 13 inflammatory, endothelial status, or oxidative stress markers. After an 8-week run-in period of high-flux hemodialysis, 17 eligible stable dialysis patients (median age 65 years, 10 male) without overt clinical inflammation were scheduled for four 8-week periods in the sequence: HFR/OLHDF/HFR/OLHDF. Relative to OLHDF, HFR was associated with greater indoxyl sulfate removal and lesser abnormalities in all other study variables, namely circulating interleukin-6, tumor necrosis factor-alpha, proportions of activated proinflammatory (CD14+CD16+, CD14++CD16+) monocytes, endothelial progenitor cells, apoptotic endothelial microparticles, vascular endothelial growth factor, vascular cellular adhesion molecule, angiopoietins 2 and 1, annexin V, and superoxide dismutase. Differences were significant (P < 0.05) in median values of 13/15 variables. Study period comparisons were generally consistent with dialysis technique comparisons, as were data from the subgroup completing all study periods (n = 9). Our investigation provides hypothesis-generating results suggesting that compared with OLHDF, HFR improves protein-bound toxin removal, inflammatory and endothelial status, and oxidative stress.

Efficiency of Original versus Generic Intravenous Iron Formulations in Patients on Haemodialysis.

AIMS: The appropriate use of intravenous (i.v.) iron is essential to minimise the requirements for erythropoiesis-stimulating agents (ESAs). The clinical efficacy of generic i.v. iron compared to the original formulation is controversial. We evaluated the changes that were induced after switching from a generic i.v. iron to an original formulation in a stable, prevalent haemodialysis (HD) population. METHODS: A total of 342 patients were included, and the follow-up period was 56 weeks for each formulation. Anaemia parameters and doses of ESA and i.v. iron were prospectively recorded before and after the switch from generic to original i.v. iron. RESULTS: To maintain the same haemoglobin (Hb) levels after switching from the generic to the original formulation, the requirements for i.v. iron doses were reduced by 34.3% (from 52.8±33.9 to 34.7±31.8 mg/week, p<0.001), and the ESA doses were also decreased by 12.5% (from 30.6±23.6 to 27±21 µg/week, p<0.001). The erythropoietin resistance index declined from 8.4±7.7 to 7.4±6.7 IU/kg/week/g/dl after the switch from the generic to the original drug (p = 0.001). After the switch, the transferrin saturation ratio (TSAT) and serum ferritin levels rose by 6.8% (p<0.001) and 12.4% (p = 0.001), respectively. The mortality rate was similar for both periods. CONCLUSIONS: The iron and ESA requirements are lower with the original i.v. iron compared to the generic drug. In addition, the uses of the original formulation results in higher ferritin and TSAT levels despite the lower dose of i.v. iron. Further studies are necessary to analyse the adverse effects of higher i.v. iron dosages.

Klotho Prevents NFκB Translocation and Protects Endothelial Cell From Senescence Induced by Uremia.

In patients with renal disease, uremia raises oxidative stress and senescence in endothelial cells, which can lead to endothelial dysfunction and cardiovascular disease. Klotho protein is a ß-glucuronidase capable of hydrolyzing steroid ß-glucuronides. This protein is recognized as an antiaging gene, that modulate both stress-induced senescence and functional response. The aim of the study was to investigate how senescence and oxidative stress induced by uremia in endothelial cells affects Klotho expression and whether intra or extracellular Klotho has effects on the response of these cells. Senescence and oxidative stress was obtained by exposure to uremic serum. Telomere length, the enzyme ß-galactosidase, and oxidative stress were studied by flow cytometry. Nuclear factor kappa B activity was determined by electrophoretic mobility shift assay. The expression of Klotho decreased with the uremia and preceded the manifestations of cell aging. Levels of intracellular Klotho decreases associated to endothelial senescence, and exogenous Klotho prevents cellular senescence by inhibiting the increase in oxidative stress induced by uremia and diminished the nuclear factor kappa B-DNA binding ability.

Endothelial damage and vascular calcification in patients with chronic kidney disease.

Vascular calcification (VC) is a frequent complication of chronic kidney disease (CKD) and is a predictor of cardiovascular morbidity and mortality. In the present study, we investigated the potential involvement of endothelial microparticles (MPs) and endothelial progenitor cells (EPCs) in the generation of VC in CKD patients. The number of circulating EMPs is greater in patients with VC than without VC (307 ± 167 vs. 99 ± 75 EMPs/µl, P < 0.001). The percentage of EPCs is significantly lower in patient with VC than in patients without VC (0.14 ± 0.11% vs. 0.25 ± 0.18%, P = 0.002). The number of EPCs expressing osteocalcin (OCN) was higher in VC patients (349 ± 63 cells/100,000) than in non-VC patients (139 ± 75 cells/100,000, P < 0.01). In vitro, MPs obtained from CKD patients were able to induce OCN expression in EPCs from healthy donors; the increase in OCN expression was more accentuated if MPs were obtained from CKD patients with VC. MPs from CKD patients also induced OCN expression in vascular smooth muscle cells and fibroblasts. In CKD patients, the rise in endothelial MPs associated with a decrease in the number of EPCs, suggesting an imbalance in the processes of endothelial damage and repair in CKD patients, mainly those with VC. Our results suggest that EPCs, through OCN expression, may directly participate in the process of VC.

Cellular senescence determines endothelial cell damage induced by uremia.

Renal dysfunction is closely associated with endothelial damage leading to cardiovascular disease. However, the extent to which endothelial damage induced by uremia is modulated by aging is poorly known. Aging can render endothelial cells more susceptible to apoptosis through an oxidative stress-dependent pathway. We examined whether senescence-associated to oxidative stress determines the injury induced by the uremia in endothelial cells. Human umbilical vein endothelial cells (HUVEC) was incubated with human uremic serum and, in the animal model, endothelial cells were obtained from aortas of uremic and no uremic rats. Vitamin C was used to prevent oxidative stress. Senescence, assessed by telomere length and enzyme-betagalactosidase (ß-gal), reactive oxygen species (ROS), mitochondrial depolarization (JC-1 probe), caspase 3, and apoptosis were determined by flow cytometry. NF-κB activity was determined by Western blot. Uremic serum increased ROS and NF-κB in young and aging HUVEC. However only in aging cells, uremic serum induced apoptosis (vs young HUVEC, p<0.01). The endothelial damage induced by uremia seems to be related with the increased oxidative stress, since in both HUVEC and in the experimental model of renal disease in rats, vitamin C prevents endothelial apoptosis. However, vitamin C did not decrease the oxidative stress associated to senescence. These results showed that as compared with young cells, senescent cells have high sensitivity to damage associated to the oxidative stress induced by the uremia. Consequently, protecting senescent endothelial cells from increased oxidative stress might be an effective therapeutic approach in the treatment of vascular disorders in chronic kidney diseases.

The effect of phosphate binders, calcium and lanthanum carbonate on FGF23 levels in chronic kidney disease patients.

BACKGROUND: Recent publications show that elevation of FGF23 is independently associated with progression or renal disease, left ventricular hypertrophy and cardiovascular mortality. Dietary restriction of phosphate and phosphate binders are used for control phosphate balance and elevation of serum FGF23 levels. The aim of this study is to compare the effectiveness of calcium carbonate vs. lanthanum carbonate in reducing serum FGF23 levels in Chronic Kidney Disease (CKD) patients. METHODS: 32 patients from the Nephrology outpatient clinic with CKD 4 - 5 non-dialysis were included. Patients receive a 4-month treatment period of calcium carbonate or lanthanum carbonate. Patients had normal serum calcium concentration, 25 (OH) levels >30 ng/ml and they were not on VDR activators or cinacalcet. RESULTS: As compared with calcium carbonate, patients on lanthanum carbonate had lower serum levels of FGF23 (226 ± 11 vs. 158 ± 9 pg/ml) and less urinary excretion of phosphate. No significant changes in serum calcium and PTH levels were observed in both groups. CONCLUSIONS: In conclusion, in CKD 4 - 5 patients lanthanum carbonate is effective in reducing phosphate load and FGF23 levels; this effect was not observed with calcium carbonate.

Effects of intravenous iron on mononuclear cells during the haemodialysis session.

BACKGROUND: This study analysed, in vivo and in vitro, the effects of four different intravenous iron preparations (iron gluconate, iron sucrose, iron dextran and ferric carboxymaltose) on activation and damage of mononuclear cells. METHODS: A randomized prospective study was conducted in 10 haemodialysis (HD) patients. Blood samples were collected at baseline (T0); 1 h after starting HD, just before the iron or saline administration (T1); 30 min after the iron or saline infusion (T2) and at the end of HD (T3). In addition, peripheral blood mononuclear cells from 10 healthy individuals and 9 chronic kidney disease Stage-5 (CKD-5) without HD treatment were cultured with the 4 iron preparations. RESULTS: Iron infusion during the HD session increased the percentage of mononuclear cells with reactive oxygen species (ROS) production, Inter-Cellular Adhesion Molecule-1 (ICAM-1) and apoptosis. There were no significant differences between the four iron preparations. Culture of mononuclear cells from healthy individuals and CKD-5 patients with the different iron preparations resulted in a significant increase in ROS, ICAM-1 and apoptosis as compared with control. In an additional study, the effect of original iron sucrose formulation on mononuclear cells was compared with that of one generic formulation. The generic formulation produced a greater increase in ROS, ICAM-1 and apoptosis than the original iron sucrose. CONCLUSIONS: Our results suggest that intravenous iron has deleterious effects on mononuclear cells. The four iron compounds evaluated produced similar effects on oxidative stress, cell activation and apoptosis. However, the effects of iron compounds with the same formulation were different, thus further investigation may be required to establish the safety of iron preparations that theoretically have the same composition.

Tandem plasmapheresis and hemodialysis: efficacy and safety.

BACKGROUND: Hemodialysis (HD) and plasmapheresis (PE) are usually performed independently on patients who require renal replacement therapy. We analyzed our experience using a technique that performs both modalities simultaneously. METHODS: Thirty-six patients who were treated with 287 tandem PE and HD (TPH) sessions (mean 7.97 ± 5.6 per patient) were included. PE was connected 30 min after HD started. The mean HD blood flow was 313.7 ± 44 mL/min, the mean PE blood flow was 141 ± 25 mL/min, and the duration of TPH was no longer than 240 min. The heparin dose was similar to that used for a standard HD procedure. RESULTS: In 287 TPH sessions performed, 10.45% experienced minor complications. There were significant changes in mean blood pressure after connection of the PE system. However, these differences were not clinically relevant since patients remained asymptomatic and they did not require saline infusion. At the end of treatment, 38.9% of patients were no longer dependent on dialysis. CONCLUSIONS: Our results suggest that TPH is a safe and effective treatment that decreases exposure to an extracorporeal circuit, reducing the risks that are associated with anticoagulation agents and improving the comfortability of the patient.