Fewer cytomegalovirus complications after kidney transplantation by de novo use of mTOR inhibitors in comparison to mycophenolic acid.

BACKGROUND: Cytomegalovirus (CMV) is a risk factor for patient and graft survival after kidney transplantation. METHODS: We retrospectively analyzed risk factors for CMV infection in 348 patients who received a kidney transplant donated after brain death (n = 232) or by living donation (n = 116) between 2008 and 2013. Of the 348 patients analyzed, 91 received a mammalian target of rapamycin inhibitor (mTORi)-based immunosuppressive regimen. A total of 266 patients were treated with standard immunosuppression (Group 1) consisting of basiliximab induction, calcineurin inhibitor (CNI), and either mycophenolic acid (MPA, n = 219) or everolimus (EVE) (n = 47). We also included 82 patients who received more intense immunosuppression (Group 2) with lymphocyte depletion, CNI, plus either MPA (n = 38) or EVE (n = 44). Only patients in the high-risk constellation received CMV prophylaxis in Group 1, while all patients in Group 2 received prophylaxis for 6 month. RESULTS: The overall rate of CMV infections was low with 10.1% in all patients. Despite the different prophylaxis strategies applied, no difference was seen in CMV infections between Group 1 (10.9%) and Group 2 (13.6%). A multivariate analysis revealed that patients on EVE had fewer CMV complications compared with patients on MPA (P = 0.013, odds ratio [OR] 4.8, confidence interval [CI] 1.4-16.5). Donor and recipient age >65 years was an independent risk factor (P = 0.002, OR 3.2, CI 1.5-6.7) for CMV infections. Patients with CMV infections had significantly worse graft function after 2 years (P = 0.001). CONCLUSION: CMV is a significant risk factor for long-term graft outcome. Patients treated with EVE developed fewer CMV complications compared to patients on MPA. The use of mTORi is useful in patients at high risk of developing CMV infections.

Two patients with history of STEC-HUS, posttransplant recurrence and complement gene mutations.

Hemolytic uremic syndrome (HUS) is a disease of microangiopathic hemolytic anemia, thrombocytopenia and acute renal failure. About 90% of cases are secondary to infections by Escherichia coli strains producing Shiga-like toxins (STEC-HUS), while 10% are associated with mutations in genes encoding proteins of complement system (aHUS). We describe two patients with a clinical history of STEC-HUS, who developed end-stage renal disease (ESRD) soon after disease onset. They received a kidney transplant but lost the graft for HUS recurrence, a complication more commonly observed in aHUS. Before planning a second renal transplantation, the two patients underwent genetic screening for aHUS-associated mutations that revealed the presence of a heterozygous CFI mutation in patient #1 and a heterozygous MCP mutation in patient #2, and also in her mother who donated the kidney. This finding argues that the two cases originally diagnosed as STEC-HUS had indeed aHUS triggered by STEC infection on a genetic background of impaired complement regulation. Complement gene sequencing should be performed before kidney transplantation in patients who developed ESRD following STEC-HUS since they may be undiagnosed cases of aHUS, at risk of posttransplant recurrence. Furthermore, genetic analysis of donors is mandatory before living-related transplantation to exclude carriers of HUS-predisposing mutations.

[Long-term outcome with end-stage renal disease - survival is not enough: does dialysis or kidney transplantation matter?]. / Langzeitüberleben bei chronischer Niereninsuffizienz.

Patients with end-stage renal disease require renal replacement therapy with either dialysis or kidney transplantation. Survival and quality of life (QoL) after transplantation are superior to chronic dialysis. Early living donor kidney transplantation is best for patient and graft survival. Preemptive living-related kidney transplantation therefore is the best medical treatment option for these patients. Patients with end-stage renal disease suffer from multiple physical and psychological complaints. The prevalence of depressive disorders is 20-25% in this population. Studies on QoL in children after kidney transplantation show a reduced physical QoL, but an overall good psychological QoL. Alarming results of numerous studies are the high non-adherence rates in adolescents. Especially exercise interventions during dialysis and after kidney transplantation show promising results. Whether QoL of patients will improve with new approaches to immunosuppressive therapy remains to be evaluated in future studies.

Analysis of Risk Factors for Allograft Outcome Comparing 2 Kidneys From the Same Donor in Separate Recipients.

BACKGROUND: An analysis of 2 kidney transplants from the same donor at the same center enables us to analyze the influence of risk factors on the outcome of the grafts in different recipients. METHODS: We retrospectively analyzed 88 kidneys from 44 donors that were implanted in 88 recipients at our institution between 2007-2016. We defined unsatisfactory outcome as glomerular filtration rate <30 mL/min/1.73 m2 allograft loss or recipient death within the first year after transplantation. Fifty-three kidneys were allocated and age-matched to donors above the age of 65 years (via Eurotransplant Senior Program or center offer). We compared kidney pairs with satisfactory outcome in both recipients (group A) to pairs with divergent outcome (group B) and unsatisfactory outcome in both recipients (group C). RESULTS: Thirty-four grafts (17 donors) had a satisfactory outcome for both recipients (group A), and 16 grafts (8 donors) had an unsatisfactory outcome for both recipients (group C). Donor age was significantly higher in group C vs group A (67.5 ± 6.7 vs 56.4 ± 16.0 years, P = .010). The 19 donors donating 1 kidney with satisfactory and the other with unsatisfactory outcome were 67.4 ± 10.7 years old (group B). A severe surgical complication occurred more often in recipients with an unsatisfactory outcome in comparison to patients with a satisfactory outcome. CONCLUSION: Donor age is an important risk factor for an unsatisfactory outcome, either in one or both kidneys of the same donor.

Outcome and natural course of renal dysfunction in liver transplant recipients with severely impaired kidney function prior to transplantation.

BACKGROUND: Since introduction of the MELD score in the liver allograft allocation system, renal insufficiency has emerged as an increasing problem. Here we evaluated the course of kidney function in patients with advanced renal insufficiency prior to liver transplantation (LT). METHODS: A total of 254 patients undergoing LT at the University Medical Centre Hamburg-Eppendorf (2011-2015) were screened for renal impairment (GFR < 30 ml/min) prior to LT in this observational study. RESULTS: Eighty (32%) patients (median 60 years; M/F: 48/32) had significant renal impairment prior to LT. Median follow-up post-LT was 619 days. Patient survival at 90 days, one year and two years was 76%, 66% and 64%, respectively. Need for dialysis postoperatively but not preoperatively was associated with increased mortality (p < 0.05). Renal function improved in 75% of survivors, but 78% of patients had chronic kidney disease ≥ stage 3 at end of follow-up. Of eight (16%) survivors remaining on long-term dialysis, so far only four patients have received a kidney transplant. CONCLUSION: Postoperative dialysis affected long-term mortality. In 75% of survivors renal function improved, but still the majority of patients had an impaired renal function (CKD stage 3-5) at end of follow-up. Future studies should elucidate the impact of kidney dysfunction and dialysis on recipients' long-term survival.

Angiotensin II stimulates expression of the chemokine RANTES in rat glomerular endothelial cells. Role of the angiotensin type 2 receptor.

Glomerular influx of monocytes/macrophages (M/M) occurs in many immune- and non-immune-mediated renal diseases. The mechanisms targeting M/M into the glomerulus are incompletely understood, but may involve stimulated expression of chemokines. We investigated whether angiotensin II (ANG II) induces the chemokine RANTES in cultured glomerular endothelial cells of the rat and in vivo. ANG II stimulated mRNA and protein expression of RANTES in cultured glomerular endothelial cells. The ANG II-induced RANTES protein was chemotactic for human monocytes. Surprisingly, the ANG II-stimulated RANTES expression was transduced by AT2 receptors because the AT2 receptor antagonists PD 123177 and CGP-42112A, but not an AT1 receptor blocker, abolished the induced RANTES synthesis. Intraperitoneal infusion of ANG II (500 ng/h) into naive rats for 4 d significantly stimulated glomerular RANTES mRNA and protein expression compared with solvent-infused controls. Immunohistochemistry revealed induction of RANTES protein mainly in glomerular endothelial cells and small capillaries. Moreover, ANG II- infused animals exhibited an increase in glomerular ED-1- positive cells compared with controls. Oral treatment with PD 123177 (50 mg/liter drinking water) attenuated the glomerular M/M influx without normalizing the slightly elevated systolic blood pressure caused by ANG II infusion, suggesting that the effects on blood pressure and RANTES induction can be separated. We conclude that the vasoactive peptide ANG II may play an important role in glomerular chemotaxis of M/M through local induction of the chemokine RANTES. The observation that the ANG II- mediated induction of RANTES is transduced by AT2 receptors may influence the decision as to which substances might be used for the therapeutic interference with the activity of the renin-angiotensin system.

Mechanisms underlying endothelial dysfunction in diabetes mellitus.

Incubation of endothelial cells in vitro with high concentrations of glucose activates protein kinase C (PKC) and increases nitric oxide synthase (NOS III) gene expression as well as superoxide production. The underlying mechanisms remain unknown. To address this issue in an in vivo model, diabetes was induced with streptozotocin in rats. Streptozotocin treatment led to endothelial dysfunction and increased vascular superoxide production, as assessed by lucigenin- and coelenterazine-derived chemiluminescence. The bioavailability of vascular nitric oxide (as measured by electron spin resonance) was reduced in diabetic aortas, although expression of endothelial NOS III (mRNA and protein) was markedly increased. NOS inhibition with N:(G)-nitro-L-arginine increased superoxide levels in control vessels but reduced them in diabetic vessels, identifying NOS as a superoxide source. Similarly, we found an activation of the NADPH oxidase and a 7-fold increase in gp91(phox) mRNA in diabetic vessels. In vitro PKC inhibition with chelerythrine reduced vascular superoxide in diabetic vessels, whereas it had no effect on superoxide levels in normal vessels. In vivo PKC inhibition with N:-benzoyl-staurosporine did not affect glucose levels in diabetic rats but prevented NOS III gene upregulation and NOS-mediated superoxide production, thereby restoring vascular nitric oxide bioavailability and endothelial function. The reduction of superoxide in vitro by chelerythrine and the normalization of NOS III gene expression and reduction of superoxide in vivo by N:-benzoyl-staurosporine point to a decisive role of PKC in mediating these phenomena and suggest a therapeutic potential of PKC inhibitors in the prevention or treatment of vascular complications of diabetes mellitus. The full text of this article is available at http://www.circresaha.org.

Cyclosporine stimulates expression of transforming growth factor-beta in renal cells. Possible mechanism of cyclosporines antiproliferative effects.

CsA induces a reversible inhibition of proliferation in cultured murine proximal tubular cells (MCT cells) and syngeneic tubulointerstitial fibroblasts (TFB). To test whether this effect may be caused by endogenous synthesis and release of transforming growth factor-beta 1 (TGF-beta 1), a well-known inhibitor of mitosis, MCT cells and TFB grown in serum-free media were treated with different concentrations of CsA. CsA, in a dose-dependent manner in a range of 500-2000 ng/ml, stimulated expression of TGF-beta 1 protein and steady-state mRNA levels in both cell lines (MCT cells: controls, 9.3 +/- 1.0; 1500 ng/ml CsA, 19.1 +/- 6.1 pg TGF-beta 1/10(3) cells [P < 0.05 vs. controls]; TFB: controls, 5.4 +/- 0.9; 1500 ng/ml CsA, 7.7 +/- 0.3 pg TGF-beta 1/10(3) cells; n = 6). Short-term daily intraperitoneal injections of CsA (40 mg/kg body weight/day) into SJL mice for 1 and 4 weeks also induced an increase in whole kidney levels of TGF-beta 1 mRNA. Incubation of MCT cells and TFB with CsA in the presence of 30 micrograms/ml of a neutralizing anti-TGF-beta 1-3 mAb partly reversed the cell cycle arrest induced by CsA. These data suggest that CsA-mediated intrarenal synthesis and release of TGF-beta 1 may play a role in the CsA-induced growth arrest and might therefore be relevant in the development of chronic CsA nephrotoxicity, which is characterized by striped fibrosis and tubular atrophy.

Renal handling of human apolipoprotein(a) and its fragments in the rat.

The sites and mechanisms of the catabolism of atherogenic lipoprotein(a) (Lp(a)) are not well understood. Lp(a) is increased in patients with end-stage renal disease, suggesting a renal catabolism of Lp(a). To gain a better insight into renal handling of Lp(a), we established a heterologous rat model to study the renal catabolism of human Lp(a). Pure human Lp(a) was injected into Wistar rats, and animals were sacrificed at different time points (30 minutes to 24 hours). Intact Lp(a) was cleared from the circulation of injected rats with a half-life time of 14.5 hours. Strong intracellular immunostaining for apolipoprotein(a) (apo(a)) was observed in the cytoplasm of proximal tubular cells after 4, 8, and 24 hours. Apolipoprotein B (apoB) was colocalized with glomerular apo(a) 1 to 8 hours after Lp(a) injection, but renal capillaries and tubules remained negative. No relevant amounts of apo(a) fragments were found in the plasma of rats after injection of Lp(a). During all urine collection periods, apo(a) fragments with molecular weights of 50 to 160 kd were detected in the urine, however. Our results show that human Lp(a) injected into rats accumulates intracellularly in the rat kidney, and apo(a) fragments are excreted in the urine. The kidney apparently plays a major role in fragmentation of Lp(a). Despite the fact that rodents lack endogenous Lp(a), rats injected with human Lp(a) may provide a useful heterologous animal model to study the renal metabolism of Lp(a) further.

Microangiopathic hemolytic anemia and renal impairment following autologous bone marrow transplantation: a case of hemolytic uremic syndrome?

Thrombotic microangiopathy, which encompasses both thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS), is a severe and life-threatening complication following bone marrow transplantation (BMT). It has been reported after allogeneic BMT but may also occur after autologous BMT. Here we describe a case of microangiopathic hemolytic anemia and progressive renal failure subsequent to autologous BMT.

Effect of cyclosporine on in situ immune complex glomerulonephritis.

The influence of Cyclosporine A (CyA) on the development of renal injury in in situ immune complex glomerulonephritis (ICGN) in rats was examined. Left kidneys of male Wistar rats were perfused with cationized human IgG followed by an intravenous injection of rabbit anti-human IgG. CyA was given orally in a dosage of either 2.5, 15 or 25 mg/kg body weight per day in two daily injections. The amount of immune complexes deposited in the left kidney was not affected by CyA application as shown by isotopic studies. There were no differences between the control and CyA groups in respect to immunofluorescence, light and electron microscopy. Proteinuria was significantly inhibited with all treatment schedules, even when rats were first treated five days after inducing nephritis. These results show that CyA inhibits proteinuria without affecting glomerular cell accumulation/proliferation in in situ ICGN, and indicates that cellular activation at glomerular level might be prevented by CyA.

Urinary protein patterns and EPH-gestosis.

In pregnancy a glomerular or mixed glomerular/tubular proteinuria in excess of 0.5 g/day was found in EPH-gestosis or preceding glomerular disease. A pure tubular proteinuria was not found in EPH-gestosis. The severity of the clinical picture was positively correlated with the daily protein loss.

Granulocyte activation during hemodialysis.

Plasma levels of granulocyte lactoferrin, myeloperoxidase, and elastase in complex with alpha 1-proteinase inhibitor (E-alpha 1PI) during hemodialysis were investigated in patients undergoing maintenance hemodialysis with dialyzers made from cellulose hydrate, polymethylmethacrylate, cuprophan, ethylene-vinyl alcohol copolymer, polycarbonate, polyacrylonitrile or polysulfone. Polymethylmethacrylate membrane caused markedly elevated plasma lactoferrin (712.5 +/- 165.9 ng/ml) and E-alpha 1PI (681.8 +/- 102.6 ng/ml). Lower levels were observed in patients dialyzed with cuprophan or polycarbonate dialyzers, while cellulose hydrate membrane caused a maximal increase of the E-alpha 1PI levels (1,6590 +/- 256.8 ng/ml). Polyacrylonitrile membrane provoked minimal E-alpha 1PI formation (267.6 +/- 79.6 ng/ml) but markedly elevated plasma levels of lactoferrin. However, polysulfone dialyzers displayed only very modest increases of the plasma E-alpha 1PI and lactoferrin levels. Plasma levels of myeloperoxidase were unchanged comparing the effects of the different dialyzers. We conclude that granulocyte activation during hemodialysis does not necessarily need anaphylatoxin formation.

High glucose induces type 1 hexokinase gene expression in isolated glomeruli of diabetic rats and in mesangial cells.

BACKGROUND: Diabetic nephropathy, which is characterized by renal hypertrophy and accumulation of extracellular matrix, is one of the leading causes for end-stage renal disease. Pathophysiological changes, which finally lead to the development of diabetic nephropathy, act through an increase in the intracellular NADH/NAD ratio and the activation of the polyol and protein kinase C pathways. The first rate-limiting enzymes in intracellular glucose metabolism are the hexokinases, which catalyze the phosphorylation of glucose. Therefore, in order to examine a possible link between increased glucose metabolism and the development of diabetic nephropathy mRNA and protein expression as well as enzyme activity of type 1 hexokinase were examined in kidneys of control and diabetic rats and in mesangial cells. METHODS: Diabetes in rats was induced by intravenous injection of streptozotocin and animals were treated or not treated with insulin. RNA or protein was extracted from isolated glomeruli at different time intervals. In addition, glomerular mesangial cells were incubated in high glucose medium and hexokinase expression determined along with enzyme activity. RESULTS: The experiments demonstrate a significant increase in gene and protein expression of type 1 hexokinase in glomeruli of diabetic rats throughout a three week observation period. Insulin therapy reduced glomerular type 1 hexokinase mRNA expression. Gene expression and hexokinase enzyme activity were also increased in mesangial cells grown in high glucose medium. CONCLUSION: The present experiments demonstrate that the expression of type 1 hexokinase is increased in isolated glomeruli of diabetic animals and is regulated by high ambient glucose concentrations. These results add further evidence to the fact that the kidney is one of the tissues most sensitive to high glucose levels in diabetes.

The effect of mTOR-inhibition on NF-κB activity in kidney ischemia-reperfusion injury in mice.

Kidney ischemia-reperfusion injury (IRI) is associated with a robust inflammatory response, which is regulated by nuclear factor-kappaB (NF-κB), mainly its heterodimeric form p65/p50. Considering immunomodulatory properties of mammalian target of rapamycin (mTOR) inhibitors, the effect of everolimus on NF-κB activation in kidney IRI was determined in this study. IRI was induced in C57/BL6 mice by clamping both renal pedicles for 45 minutes. Application of everolimus (0.25 mg/kg bw subcutaneously daily) was started one day before IRI induction. Both everolimus-treated and nontreated mice were sacrificed at several times starting at 30 minutes and finishing on day 7 after IRI induction. The NF-κB activity, proinflammatory cytokines IL-1ß, TNF-α, and anti-inflammatory cytokine IL-10 production were determined in kidneys. Compared with nontreated animals, everolimus-treated animals showed significantly increased TNF-α (2741.6 ± 201.72 pg/mg; 1925 ± 185.81 pg/mg, P < .05) and IL-1ß (11.47 ± 1.2 pg/mg; 4.3 ± 0.13 pg/mg, P < .01) production on day 2 after IRI induction accompanied by significantly greater NF-κB/DNA binding activity and p65 nuclear expression (P < .01). Two hours after IRI induction, everolimus-treated animals showed significantly increased IL-1ß mRNA expression (P < .05) followed by increased IL-1ß protein concentrations when compared with nontreated animals measured 6 hours after IRI induction (11.71 ± 1.5 pg/mg; 7.5 ± 1.11 pg/mg, P < .01). Both experimental groups showed increased NF-κB/DNA binding activity at 7 days after IRI induction. Significantly increased nuclear p65 expression was measured in nontreated animals (P < .01), whereas everolimus-treated hosts showed significantly increased nuclear RelB expression (P < .01). These data suggested that everolimus potentiated innate immunity in the early phase of IRI, stimulating the production of NF-κB-driven proinflammatory cytokines such as TNF-α and IL-1ß. The NF-κB activity was potentiated under m-TOR inhibition during kidney IRI, implicating a possible beneficial role of alternative NF-κB activation during the repair phase.

A new mouse model of immune-mediated podocyte injury.

Podocytes play a major role in the initiation and progression of glomerular diseases and are a target of both immune-mediated and non-immune-mediated injury. To establish a mouse model of such injury, we preimmunized mice with Freunds adjuvant 5 days before intravenous injection of a rabbit polyclonal antibody directed against a murine podocyte cell line. For the next 7 weeks, we collected urine, serum, and kidney samples. Nephritic animals developed severe albuminuria, which was maximal on day 10. Histochemistry revealed diffuse mesangial matrix expansion. Mouse immunoglobulin G and complement were detected in a linear pattern along the glomerular filtration barrier and in the mesangial hinge region. Complement depletion, however, did not prevent proteinuria. Glomerular T cells were increased, whereas podocytes were significantly reduced. Glomerular foot processes were flattened in regions with mesangial matrix deposition as viewed by electron microscopy. Immunohistochemistry detected the injected anti-podocyte antibody exclusively at the glomerular tuft on all days examined. Immunoelectron microscopy localized the antibody to podocyte foot processes and the glomerular basement membrane, which was morphologically intact. This suggests that the podocyte was the main target of the antiserum. Our study establishes a new mouse model of immune-mediated podocyte injury.

[The kidney in diabetes mellitus--new aspects on pathogenesis, diagnosis and therapy]. / Die Niere bei Diabetes mellitus--Neue Aspekte zur Pathogenese, Diagnostik und Therapie.

The knowledge about the pathogenesis of the diabetic nephropathy has significantly increased during the last years. The diabetic nephropathy is one of the best treatable renal disease due to the treatment strategies derived from this knowledge and the new emerging therapeutic perspectives. However, it is a prerequisite that the treatment is started early in the course of the disease. The onset of microalbuminuria is currently the known indication for the development of a nephropathy in a patient with diabetes. Additional to the intensified insulin treatment, the application of an ACE-inhibitor should be taken into account when microalbuminuria occurs.

[Therapy of diabetic nephropathy]. / Therapie der diabetischen Nephropathie.

New pathophysiological insights in the last few years on the development of diabetic nephropathy have led to a change in therapeutic measures. The emphasis is put on preventive considerations for the insulin-dependent diabetic patient. Strict control of glycemia and the early use of an angiotensin-conversion inhibitor are of importance. Therapy of the manifest diabetic nephropathy is based on strict metabolic control combined with reduced protein intake. Furthermore, an often co-existing hypertension needs to be treated. Normotensive blood pressure should be obtained. ACE-inhibitors and Ca-antagonists have been proven to be very effective, although there seem to exist differences in the type of Ca-antagonists regarding effectiveness on albuminuria. The combination of ACE-inhibitors and Ca-antagonists seems to have an additional beneficial impact on albuminuria. A significant decrease in the loss of glomerular function and a decrease in albuminuria can be obtained by consistent consideration of these therapeutic strategies.

[Orbital phlegmon in childhood]. / Orbitalphlegmone im Kindesalter.

Between 1970 and 1980 there were 43 patients (28 boys, 15 girls) treated for an orbital cellulitis at the Freiburg University Children's Hospital. The most frequent underlying condition is maxillary or ethmoidal sinusitis. The most frequent causative agents are pneumococci and staphylococci. Vigorous antibiotic treatment with ampicillin, oxacillin, and - if necessary - with chloramphenicol is absolutely considered to be the therapy of choice as compared to any surgical procedure; this holds also true of the more advanced stages of orbital involvement, provided the cellulitis is primarily due to infection and not primarily due to a traumatic lesion of the orbital area.

Detection of a metalloproteinase in patients with acute and chronic renal failure.

The effect of different dialyzer membrane materials (cuprophan, cellulose hydrate, polyacrylonitrile, polymethylmethacrylate, ethylene-vinyl alcohol copolymer) on the ultrafiltrate proteinase activity was investigated in 26 patients with acute renal failure (ARF) and 40 patients undergoing regular hemodialysis treatment (RDT). Furthermore, the proteinase activity was characterized in vitro using azocasein and phosphorylase kinase as substrates in the absence and presence of different proteinase inhibitors. Proteinase activity of ultrafiltrates obtained from ARF patients was significantly enhanced with the dialyzer KF 101 (ethylene-vinyl alcohol copolymer). The digestion pattern of phosphorylase kinase revealed an identical type of proteinases in ultrafiltrates of ARF and RDT patients. The pH optimum of this proteinase was at alkaline pH. The proteinase activity could be inhibited in the presence of EDTA, whereas serine proteinase inhibitors were ineffective. Furthermore, the inactivated proteinase after Sephadex G-10 chromatography (in order to separate ultrafiltrate electrolytes and trace elements from protein) could be reactivated after the addition of Mg++ and/or Ca++. We conclude that a metalloproteinase can be found in ARF and RDT patients, and that KF 101 is more effectively eliminating the proteinase activity in ARF patients than other dialyzer membranes.