Prometheus--a new extracorporeal system for the treatment of liver failure

BACKGROUND/AIMS: Extracorporeal detoxification systems for supportive therapy of liver failure have recently gained much interest. We herein report results from the first clinical application of Prometheus, a new liver support system in which albumin-bound substances are directly removed from blood by special adsorber. In a simultaneous step, high-flux hemodialysis is performed. We assessed safety, adsorber efficiency and clinical efficacy of the Prometheus system. METHODS: Eleven patients with acute-on-chronic liver failure and accompanying renal failure were treated with Prometheus on 2 consecutive days for >4 h. RESULTS: Prometheus treatment significantly improved serum levels of conjugated bilirubin, bile acids, ammonia, cholinesterase, creatinine, urea and blood pH. There were no significant changes in hemoglobin and platelet levels, whereas leucocytes increased without signs of systemic infection. No treatment-related complications except a blood pressure drop in two patients with systemic infection were noted. In one patient (Child-Pugh score: 15) Prometheus treatment could not be completed due to onset of uncontrolled bleeding 16 h after dialysis. CONCLUSIONS: Prometheus is a safe supportive therapy for patients with liver failure. A significant improvement of the biochemical milieu was observed already after two treatments. Prospective controlled studies with the Prometheus system are necessary to evaluate hard clinical end-points.     

Once-Monthly Continuous Erythropoietin Receptor Activator (C.E.R.A.) in Patients with Hemodialysis-Dependent Chronic Kidney Disease: Pooled Data from Phase III Trials

Introduction

Erythropoiesis-stimulating agents and iron are commonly used in patients with chronic kidney disease with the aim of correcting anemia and maintaining stable hemoglobin levels. We analyzed pooled data from 13 studies with similar designs included in the Umbrella Continuous Erythropoietin Receptor Activator (C.E.R.A.) program to investigate the effects of continuous erythropoiesis receptor activator in clinically relevant subgroups of patients with chronic kidney disease and to determine whether the efficacy and safety outcomes demonstrated in the overall chronic kidney disease population are maintained in specific subgroups.

Methods

Data from 13 Phase III trials set up with similar design were retrospectively pooled for this analysis. Patients with chronic kidney disease who had previously been receiving epoetin or darbepoetin were switched to continuous erythropoiesis receptor activator once-monthly after a 4- to 8-week screening period. Patients entered a 16-week continuous erythropoiesis receptor activator dose-titration period followed by an 8-week evaluation period. In total, 2060 patients were included in the analysis. Subgroups were defined based on: hemoglobin target range [lower (10.0–12.0 g/dL)/upper (10.5–13.0 g/dL)], gender (female/male), age (<65/≥65), baseline N-terminal pro-B-type natriuretic peptide levels (<5000/≥5000), cardiovascular risk factors (diabetes/cardiac/vascular/none).

Results

Across all subgroups analyzed, switching from shorter-acting erythropoiesis-stimulating agents to continuous erythropoiesis receptor activator once-monthly maintained stable hemoglobin concentrations in a high proportion of patients (78%), with only moderate hemoglobin fluctuations and a low number of dose changes. The safety profile across subgroups was as expected based on pre-existing risk factors; observed increases in adverse events were attributable to underlying risk factors rather than study drug.

Conclusions

This retrospective analysis of 13 trials showed that continuous erythropoiesis receptor activator once-monthly maintained stable hemoglobin levels across a number of clinically relevant patient subgroups, including those with higher inherent cardiovascular risk. The safety profile was consistent with that previously established in the chronic kidney disease population.

ClinicalTrials.gov identifiers

NCT00413894/NCT00545571/NCT00517413/NCT00560404/NCT00882713/NCT00550680/NCT00576303/NCT00660023/NCT00717821/NCT00642850/NCT00605293/NCT00661505/NCT00699348.

Funding

F. Hoffmann-La Roche Ltd, Basel, Switzerland.

     

Vascular endothelial damage and repair in antineutrophil cytoplasmic antibody–associated vasculitis

Objective

Antineutrophil cytoplasmic antibody–associated vasculitis (AAV) is characterized by necrotizing vessel wall inflammation, paralleled by the detachment of endothelial cells. The repair of such endothelial defects is crucial for the maintenance of regular structure and function of the injured vessels. Bone marrow–derived endothelial progenitor cells (EPCs) are thought to play a pivotal role in the regeneration of damaged endothelium. The aim of this study was to investigate whether EPCs are involved in vascular repair in AAV.

Methods

We assessed disease activity, CD34+ hematopoietic progenitor cells (HPCs) using flow cytometry, EPCs using an in vitro assay, and circulating endothelial cells (CECs) by immunomagnetic isolation from the peripheral blood of 31 patients with active AAV at 1, 3, and 6 months after the initiation of immunosuppressive therapy.

Results

In patients with untreated active disease, HPC and EPC numbers were comparable with those in healthy control subjects (n = 64). With the induction of remission, the number of HPCs and EPCs increased significantly, from a median of 1.5 cells/μl (range 0.0–7.0) to a median of 3.2 cells/μl (range 0.76–9.2) (P < 0.001) and from a median of 261 cells/high‐power field (range 171–643) to a median of 470 cells/high‐power field (range 168–996) (P < 0.021), respectively. In contrast, the initially elevated number of CECs decreased significantly (P < 0.001). We observed no correlation between the number of HPCs or EPCs and the leukocyte count, the thrombocyte count, or kidney function.

Conclusion

In patients with AAV, the numbers of circulating CD34+ HPCs and EPCs increased significantly after the institution of immunosuppressive therapy and disease remission. This finding points to a role of circulating CD34+ HPCs and EPCs in endothelial repair in vasculitis. Targeted stimulation of these cells might represent a new possibility of improving vascular healing in AAV.

     

Monocyte Angiotensin Converting Enzyme Expression May Be Associated with Atherosclerosis Rather than Arteriosclerosis in Hemodialysis Patients

Summary

Background and objectives

Circulating monocytes can be divided into functionally distinct subpopulations according to their surface expression of CD14 and CD16. Monocytes with high-level expression of both antigens (CD14⁺⁺CD16⁺, Mo2 cells) are associated with cardiovascular morbidity and mortality in hemodialysis patients. These cells express angiotensin converting enzyme (ACE) on their surface. They are involved in the association of chronic inflammation and cardiovascular disease in kidney patients. Cardiovascular morbidity results from atherosclerosis (plaque-forming, vessel occluding disease) and arteriosclerosis (loss of arterial dampening function). It is unknown whether ACE-expressing proinflammatory monocytes are related to atherosclerosis, arteriosclerosis, or both.

Design, setting, participants, & measurements

During baseline examination for a prospective study on monocyte ACE expression and mortality, 60 chronic hemodialysis patients of an academic outpatient center were screened for atherosclerosis by carotid artery ultrasound, for arteriosclerosis by pulse pressure measurement, and for ACE expression on Mo2 cells by flow cytometry.

Results

ACE expression on Mo2 monocytes was significantly higher in patients with severe compared with those with little or no carotid atherosclerosis. Mo2 ACE correlated with a score to semiquantify atherosclerosis and remained a significant predictor of carotid plaques in multivariate analysis including the other univariately associated variables of age, hemoglobin A1c, and albumin. Mo2 ACE was not related to pulse pressure.

Conclusions

ACE expression on Mo2, although being a known predictor of mortality and cardiovascular disease in end-stage renal disease patients, may act via enhancement of atherosclerosis rather than arteriosclerosis.     

Conservative Treatment of the Uremic Syndrome

In addition to extracorporeal renal replacement strategies, which in chronic kidney disease (CKD) are largely reserved for the treatment of end-stage kidney failure, conservative measures can be taken to reduce concentration, effects, or both concentration and effects of uremic retention solutes. In this overview, we will focus on those therapies, which are aimed at preventing or delaying cardio-vascular disease, retarding or halting the progression of CKD, or both. We will discuss, consecutively, inhibitors of the renin–angiotensin–aldosterone axis, beta-blockers, calcium-channel antagonists, anti-inflammatory drugs, intestinal sorbents, calcimimetics, and glitazones. Some of these approaches could lead to a therapeutic breakthrough in the future. In addition, comprehensive tables will be provided for more traditional therapeutic approaches, such as lifestyle changes and other pharmaceutical treatments.