Effect of Extracorporeal Liver Support by Molecular Adsorbents Recirculating System and Prometheus on Redox State of Albumin in Acute-on-Chronic Liver Failure

Application of effective albumin concentration in treatment of chronic liver disease

Albumin is a non-glycosylated plasma protein. Besides the role of increasing blood volume and maintaining plasma colloid osmotic pressure, albumin also has multiple biological functions such as transport, antioxidant and anti-inflammatory effects, immune regulation, etc. In-depth studies on the structure and function of albumin have revealed that the post-transcriptional modification of albumin reduces the effective albumin concentration in patients with chronic liver disease, so the clinically effective albumin concentration rather than total albumin concentration can more accurately reflect the disease progression and prognosis, and more effectively guide exogenous albumin treatment in such patients. This article summarizes the clinical correlation between post-transcriptional modification of albumin and the liver and its related diseases, as well as the studies on effective albumin, in order to provide evidence-based information on effective albumin concentration and to better guide the clinical treatment of chronic liver disease.

Severe and long-lasting alteration of albumin redox state by plasmapheresis

Plasmapheresis (PE) is an established form of therapeutic apheresis (TA). Purpose of this longitudinal prospective single center study was to investigate the effect of PE on albumin redox state (ARS), as infusion of commercial albumin during PE may alter albumin oxidation which has an impact on its functional properties and oxidative stress level. 43 subjects with autoimmune-mediated neurological disorders were included. 20 subjects in the experimental group received five treatments of PE. 13 subjects received five treatments of immunoadsorption and 10 subjects received no TA as controls. ARS was determined before and after TA and 12 days after the last TA by fractionating it into human mercaptalbumin (HMA), human non-mercaptalbumin 1 (HNA-1), and human non-mercaptalbumin 2 (HNA-2) by high-performance liquid chromatography. Irreversibly oxidised HNA-2 increased over the course of five PE treatments from 2.8% (IQR 1.3–3.7%) to 13.6% (IQR 10.9–15.9) (P < 0.01) and remained elevated 12 days after the last PE procedure (7.7% IQR 7.1–10.5, P < 0.05). The study showed for the first time that PE exerts a severe and long-lasting alteration on ARS indicating a new adverse effect of PE, that may influence oxidative stress level.

Management of Acute Wilsonian Hepatitis with Severe Hemolysis: A Successful Combination of Chelation and MARS Dialysis

Wilson's disease is a rare hereditary disorder of copper metabolism leading to progressive accumulation of copper in several organs including the brain and the liver. Acute liver failure is a relatively rare hepatic manifestation of WD which may require urgent liver transplantation if medical treatment fails. We report here the case of a young woman who presented with classic acute Wilsonian hepatitis complicated by liver and renal failure and a severe hemolysis related to massive nonceruloplasmin bound copper accumulation requiring repeated blood transfusions. The early initiation of a combined treatment including conventional chelation therapy and repeated MARS dialysis sessions allowed a rapid control of hemolysis, a progressive decrease of free copper overload, and clinical recompensation without liver transplantation.

Serum Albumin Redox States: More Than Oxidative Stress Biomarker

Serum albumin is the most abundant circulating protein in mammals including humans. It has three isoforms according to the redox state of the free cysteine residue at position 34, named as mercaptalbumin (reduced albumin), non-mercaptalbumin-1 and -2 (oxidized albumin), respectively. The serum albumin redox state has long been viewed as a biomarker of systemic oxidative stress, as the redox state shifts to a more oxidized state in response to the severity of the pathological condition in various diseases such as liver diseases and renal failures. However, recent ex vivo studies revealed oxidized albumin per se could aggravate the pathological conditions. Furthermore, the possibility of the serum albumin redox state as a sensitive protein nutrition biomarker has also been demonstrated in a series of animal studies. A paradigm shift is thus ongoing in the research field of the serum albumin. This article provides an updated overview of analytical techniques for serum albumin redox state and its association with human health, focusing on recent findings.

Mean Platelet Volume/Lymphocyte Ratio as a Prognostic Indicator for HBV-Related Decompensated Cirrhosis

Aim

To evaluate the prognostic role of the mean platelet volume/lymphocyte ratio (MPVLR) for mortality in patients with hepatitis B virus-related decompensated cirrhosis (HBV-DeCi).

Methods

The medical records of 101 patients with HBV-DeCi were retrospectively reviewed, and their baseline clinical and laboratory characteristics were extracted. The predictive value of the MPVLR for death was estimated using receiver operating characteristic curve analysis and a multivariate logistic regression model.

Results

Patients with HBV-DeCi in the high-MPVLR group exhibited significantly increased 90-day mortality compared with that of the patients within the low-MPVLR group, and MPVLR was an independent predictor of 90-day mortality in patients with HBV-DeCi.

Conclusions

Increased MPVLR is associated with poor outcomes in patients with HBV-DeCi and might be a useful component of future prognostic scores.

Evaluation of the neutrophil-to-lymphocyte ratio, monocyte-to-lymphocyte ratio, and red cell distribution width for the prediction of prognosis of patients with hepatitis B virus-related decompensated cirrhosis

Background

The development and progression of hepatitis B virus‐related decompensated cirrhosis (DeCi) is associated with inflammatory responses. The monocyte‐to‐lymphocyte ratio (MLR), neutrophil‐to‐lymphocyte ratio (NLR), and red cell distribution width (RDW) are well‐known inflammation markers. We aimed to assess the utility of these parameters for predicating the prognosis of patients with HBV‐DeCi.

Methods

We retrospectively recruited 174 patients diagnosed with HBV‐DeCi. Univariate and multivariate regression models were used to determine risk factors for mortality. Areas under the receiver operating characteristic curves were calculated to estimate and compare the predictive values of the three parameters. Hepatic function was evaluated using the Model for End‐Stage Liver Disease (MELD) score.

Results

The NLR, RDW, and MLR were found to be significantly higher in patients who did not survive compared with surviving patients. Moreover, these variables were all able to predict early poor outcomes in patients with HBV‐DeCi, with NLR exhibiting the highest accuracy. Furthermore, a combination of the NLR and MELD score was a more accurate prognostic marker for predicting mortality than either marker alone in such patients.

Conclusions

Hematological parameters can provide prognostic information for patients with HBV‐DeCi. Routine assessment of these parameters at admission may provide valuable data to complement other conventional measures for assessing disease condition in patients with HBV‐DeCi.

Haematologic indices in hepatitis B virus-related liver disease

Several markers and prognostic scores have been identified for predicting the development and progression of liver disease; among them, haematological parameters (the neutrophil to lymphocyte ratio (NLR), monocyte to lymphocyte ratio (MLR), platelet to lymphocyte ratio (PLR), red cell distribution width (RDW), RDW to platelet ratio (RPR), mean platelet volume (MPV), and mean corpuscular volume (MCV)) have recently gained significant interest. Compared with traditional prognostic factors, haematological indices are easy to obtain and relatively inexpensive. There is growing evidence that these haematological indices play a key role in HBV-related liver diseases and has been proposed as a predictive marker of adverse outcomes in these patients. This article focuses on discussing the diagnostic and prognostic value of the haematological indices in patients with HBV-related liver diseases.

Oxidized Albumin Triggers a Cytokine Storm in Leukocytes Through P38 Mitogen-Activated Protein Kinase: Role in Systemic Inflammation in Decompensated Cirrhosis

Decompensated cirrhosis is characterized by exuberant systemic inflammation. Although the inducers of this feature remain unknown, the presence of circulating forms of oxidized albumin, namely human nonmercaptalbumin 1 (HNA1) and HNA2, is a common finding in cirrhosis. The aim of this study was to explore the ability of these oxidized albumin forms to induce systemic inflammation by triggering the activation of peripheral leukocytes. We observed significantly higher plasma levels of HNA1 and HNA2 in patients with cirrhosis (n = 256) compared to healthy volunteers (n = 48), which gradually increased during the course from compensated to decompensated to acute-on-chronic liver failure. Plasma HNA1 and HNA2 levels significantly correlated with inflammatory markers (i.e., interleukin-6 [IL-6], IL-1β, tumor necrosis factor-alpha [TNF-α] and IL-8) in patients with cirrhosis. To directly test the inflammatory effects of HNA1 and HNA2 on leukocytes, these oxidized albumin forms were prepared ex vivo and their posttranslational modifications monitored by liquid chromatography (LC)-quadrupole time-of-flight/mass spectrometry (MS). HNA1, but not HNA2, increased IL-1β, IL-6, and TNF-α mRNA and protein expression in leukocytes from both healthy volunteers and patients with cirrhosis. Moreover, HNA1 up-regulated the expression of eicosanoid-generating enzymes (i.e., cyclooxygenase-2 [COX-2] and microsomal prostaglandin E [PGE] synthase 1) and the production of inflammatory eicosanoids (PGE₂ , PGF_2α , thromboxane B₂ , and leukotriene B₄ ), as determined by LC-electrospray ionization-MS/MS. The inflammatory response to HNA1 was more pronounced in peripheral blood mononuclear cells (PBMCs) and marginal in polymorphonuclear neutrophils. Kinome analysis of PBMCs revealed that HNA1 induced the phosphorylation of p38 mitogen-activated protein kinase, the inhibition of which blocked HNA1-induced cytokine and COX-2 induction. Conclusion: HNA1 triggers an inflammatory response in PBMCs, providing a rationale for its removal and replacement by reduced albumin in the prevention of systemic inflammation in patients with advanced liver disease.

Prometheus therapy for the treatment of acute liver failure in patients after cardiac surgery

Introduction

Acute liver failure usually develops in multiple organ dysfunction syndrome and significantly increases the mortality risk in patients after cardiac surgery.

Aim

To assess the safety and efficacy of extracorporeal liver support in patients with acute liver failure after cardiac surgery.

Material and methods

We studied 39 adult patients with multiple organ dysfunction syndrome and acute liver failure as postoperative complication, treated with Prometheus therapy. Inclusion criteria comprised clinical and laboratory signs of acute liver failure. Criteria to start Prometheus therapies were: serum bilirubin above 180 µmol/l (reference values: 3-17 µmol/l), hepatocyte cytolysis syndrome (at least 2-fold increase in aspartate aminotranspherase and alanine aminotranspherase concentrations; reference values 10-40 U/l) and decrease in plasma cholinesterase (reference values 4490-13 320 U/l).

Results

Extracorporeal therapy provided stabilization of hemodynamics, decrease in serum total bilirubin and unconjugated bilirubin levels, decrease in cytolysis syndrome severity and positive effect on the synthetic function of the liver. The 28-day survival rate in the group treated with Prometheus therapy was 23%.

Conclusions

Prometheus procedures could be recommended as a part of combined intensive care in patients with acute liver failure after cardiac and major vessel surgery. The efficiency of this method could be improved by a multi-factor evaluation of patient condition in order to determine indications for its use.

Evaluation of human nonmercaptalbumin as a marker for oxidative stress and its association with various parameters in blood

Oxidative status of albumin was not a useful biomarker for oxidative stress in practical use due to time-consuming measuring method. We evaluated oxidized, human nonmercaptalbumin measured more quickly than ever by a novel method using anion-exchange HPLC. In 60 subjects taking a general health examination, mean serum human nonmercaptalbumin level was 25.1 ± 3.0% with no gender difference but positive correlation with age. There were no links between human nonmercaptalbumin and C-reactive protein, γ-glutamyltransferase or iron, reportedly associated with oxidative stress. Human nonmercaptalbumin correlated with systolic blood pressure, pulse pressure and body mass index among physical findings. Positive correlations were observed between human nonmercaptalbumin and AST, LDH, BUN, or creatinine, suggesting that oxidative stress may link with liver injury and renal function. Human nonmercaptalbumin correlated with uric acid in female but not in male, suggesting that higher uric acid levels may be associated with increased oxidative stress only in female. As another gender difference, white blood cell counts correlated with human nonmercaptalbumin in female, while the parameters for red blood cells correlated with human nonmercaptalbumin in male. In conclusion, serum human nonmercaptalbumin level in healthy subjects was approximately 25% as previously reported. Oxidative stress may be closely associated with hypertension, obesity, liver injury, renal function, and anemia.

Comparison of quality of human serum albumin preparations in two pharmaceutical products

Aim

Human serum albumin (HSA) is known for its multiple functions, such as maintenance of colloid osmotic pressure, transport of endogenous and exogenous substances, and antioxidation. The aim of this study was to measure the redox state and concentrations of β‐d‐glucan and endotoxin to compare the quality of 5% HSA preparations from two different manufacturers.

Methods

The quality of 5% HSA preparations in two different pharmaceutical products (groups A and B) was compared in terms of the percentage of reduced and oxidized albumin and the contaminant level of β‐d‐glucan and endotoxin.

Results

The percentage of human mercaptoalbumin in group A was significantly higher than that in group B (P < 0.01), whereas that of human non‐mercaptoalbumin‐2 in group A was significantly lower (P < 0.01). The concentration of β‐d‐glucan in group A was significantly lower than in group B (P < 0.01).

Conclusions

The present findings indicate the need for quality control of HSA preparations in applications involving the use of large volumes.

Effect of therapeutic plasma exchange on plasma levels and total removal of adipokines and inflammatory markers

Background

Aside from well-established inflammatory mediators adipokines have recently been found to play an important role in a variety of immunologic diseases. Therapeutic plasma exchange (TPE) is an established treatment modality for the acute removal of pathophysiological relevant disease mediators. The aim of this study was to determine adipokine removal during TPE therapy.

Methods

21 Caucasian patients (10 females, 11 males) with an indication for TPE using albumin as exchange fluid received two consecutive TPE sessions. Blood samples for measurement of resistin, leptin, sICAM-1, sCD40L, MCP-1, and sTNF-R were drawn before and at the end of each TPE session. Samples from the total removed plasma were collected at the end of every treatment.

Results

We found a significant reduction in pre- vs. post-TPE plasma concentrations for sICAM-1 (517 ± 246 vs. 260 ± 159 ng/ml, p < 0.0001), sTNF-R (8.1 ± 6.4 vs. 5.7 ± 3.9 ng/ml, p < 0.05), and resistin plasma levels (14.3 ± 6.9 vs. 9.5 ± 4.7 ng/ml, p < 0.001). Solely sICAM-1 reduction persisted for 25 ± 5 h between the first and second TPE treatment, while the other investigated mediators increased to baseline levels. Substantial amounts of all measured mediators could be recovered from the removed plasma.

Conclusions

TPE provides a persistent reduction in sICAM-1 levels and temporarily affects several adipokine and cytokine plasma levels. Our findings are of importance not only for the interpretation of blood levels of cytokines in patients undergoing TPE but provide solid evidence that TPE markedly decreases sICAM-1.

Albumin in chronic liver disease: structure, functions and therapeutic implications

Human serum albumin is a critical plasma protein produced by the liver with a number of accepted clinical indications in chronic liver disease including management of circulatory and renal dysfunction in patients with ascites. Advanced cirrhosis is characterised by reduced albumin concentration as well as impaired albumin function as a result of specific structural changes and oxidative damage. Traditionally, the biologic and therapeutic role of albumin in liver disease was attributed to its oncotic effects but it is now understood that albumin has a wide range of other important physiologic functions such as immunomodulation, endothelial stabilisation, antioxidant effects and binding multiple drugs, toxins and other molecules. This review discusses the multifunctional properties of albumin and, in particular, the biologic and clinical implications of structural and functional changes of albumin that are associated with cirrhosis. Based on these insights, we explore the current and potential future therapeutic uses of albumin in liver disease.

Extracorporeal liver assist device to exchange albumin and remove endotoxin in acute liver failure: Results of a pivotal pre-clinical study

BACKGROUND & AIMS

In acute liver failure, severity of liver injury and clinical progression of disease are in part consequent upon activation of the innate immune system. Endotoxaemia contributes to innate immune system activation and the detoxifying function of albumin, critical to recovery from liver injury, is irreversibly destroyed in acute liver failure. University College London-Liver Dialysis Device is a novel artificial extracorporeal liver assist device, which is used with albumin infusion, to achieve removal and replacement of dysfunctional albumin and reduction in endotoxaemia. We aimed to test the effect of this device on survival in a pig model of acetaminophen-induced acute liver failure.

METHODS

Pigs were randomised to three groups: Acetaminophen plus University College London-Liver Dialysis Device (n=9); Acetaminophen plus Control Device (n=7); and Control plus Control Device (n=4). Device treatment was initiated two h after onset of irreversible acute liver failure.

RESULTS

The Liver Dialysis Device resulted in 67% reduced risk of death in acetaminophen-induced acute liver failure compared to Control Device (hazard ratio=0.33, p=0.0439). This was associated with 27% decrease in circulating irreversibly oxidised human non-mercaptalbumin-2 throughout treatment (p=0.046); 54% reduction in overall severity of endotoxaemia (p=0.024); delay in development of vasoplegia and acute lung injury; and delay in systemic activation of the TLR4 signalling pathway. Liver Dialysis Device-associated adverse clinical effects were not seen.

CONCLUSIONS

The survival benefit and lack of adverse effects would support clinical trials of University College London-Liver Dialysis Device in acute liver failure patients.

Elevated mean platelet volume is associated with poor short-term outcomes in hepatitis B virus-related acute-on-chronic liver failure patients

BACKGROUND AND AIM

It has been shown that mean platelet volume (MPV) can be used as a prognostic biomarker in some chronic diseases. The aim of the present study is to investigate the possible association between MPV and clinical outcome and prognosis in patients with HBV-related acute-on-chronic liver failure (HBV-ACLF) within 4 weeks.

METHODS

This study included 64 patients with HBV-ACLF, 19 chronic hepatitis B (CHB) patients, 27 patients with hepatitis B-related cirrhosis (CR, Child-Pugh A/B), 51 healthy subjects (healthy controls [HC]). The complete blood counts and biochemical examination of blood were obtained after 12h of fasting. In the ACLF group, the relationships between the prognosis and the MPV were analyzed.

RESULTS

At baseline, a statistically significant increase in MPV was shown in patients with ACLF (median 9.5, range 7.1-14.1) compared with HC (8.0, 7.2-11.9, P<0.001), CR (8.4, 5.9-11.1, P<0.001) and CHB (8.3, 7.3-12.0, P<0.001). The MPV value was positively correlated with model of end-stage liver disease (MELD) score and international normalized ratio (INR). The MPV level was significantly increased in nonsurvivors than survivors. High MPV level showed a significantly lower survival rate (P=0.001). Multivariate logistic regression analysis showed that only MPV level was independent factor predicting poor short-term outcomes.

CONCLUSION

MPV values at presentation were higher among nonsurvivors than survivors, and this parameter was well correlated with liver function parameters and may be used as a predictor for 4-week mortality rate in patients with HBV-ACLF.

Dysregulated iron homeostasis is strongly associated with multiorgan failure and early mortality in acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is an ailment with high incidence of multiorgan failure (MOF) and consequent mortality. Dysregulated iron homeostasis and macrophage dysfunction are linked to increased incidence of MOF. We investigated whether a panel of circulating iron-regulating proteins are associated with development of MOF and can predict 15- or 30-day mortality in ACLF patients. One hundred twenty patients with ACLF, 20 patients with compensated cirrhosis, and 20 healthy controls were studied. Relative protein expression profiling was performed in the derivative cohort and confirmed in the validation cohort. A panel of iron regulators and indices were determined. Multiparametric flow cytometry for quantitation of labile iron pool (LIP) was performed. Validation studies confirmed lower serum transferrin (Tf) and ceruloplasmin levels in ACLF and ACLF-MOF, compared to patients with cirrhosis and controls (P < 0.01). Serum iron and ferritin levels were markedly elevated (P < 0.001; P < 0.05) and hepcidin levels were lower (P < 0.001) in ACLF patients with MOF than those without and other groups (P < 0.001). Percentage Tf saturation (%SAT) was higher in ACLF-MOF (39.2%; P < 0.001) and correlated with poor outcome (hazard ratio: 6.970; P < 0.01). Intracellular LIP indices were significantly elevated in the subsets of circulating macrophages in ACLF-MOF, compared to other groups (P < 0.01). Whereas expression of iron-regulatory genes was markedly down-regulated, genes related to endoplasmic reticulum stress, apoptosis, and inflammation were up-regulated in ACLF patients, compared to patients with cirrhosis. Severe dysregulation of autophagy mechanisms was also observed in the former.

CONCLUSIONS

Iron metabolism and transport are severely deranged in ACLF patients and more so in those with MOF. %SAT, circulating hepcidin, and LIP in macrophages correlate with disease severity and %SAT could be used for early prognostication in ACLF patients.

Oxidative albumin damage in chronic liver failure: relation to albumin binding capacity, liver dysfunction and survival

BACKGROUND & AIMS

Impaired binding function of albumin has been demonstrated in end-stage liver disease. This and other functional disturbances of albumin may be related to oxidative stress which is believed to play an important role in the pathogenesis of liver failure as well as sepsis. The aim of the present study was to relate oxidative modification of albumin to loss of albumin binding function in advanced chronic liver failure and in sepsis.

METHODS

Patients with decompensated cirrhosis or sepsis and healthy controls were investigated. Three fractions of albumin were separated by chromatography according to the redox state of cysteine-34: non-oxidized human mercaptalbumin, reversibly oxidized human non-mercaptalbumin-1, and irreversibly oxidized human non-mercaptalbumin-2 (HNA2). Binding properties of albumin site II were measured using dansylsarcosine as a ligand.

RESULTS

Both in cirrhotic and septic patients, fractions of oxidized albumin were increased and binding capacity for dansylsarcosine was decreased. Mass spectroscopy confirmed specific oxidation of cysteine-34. In cirrhotic patients, dansylsarcosine binding correlated strongly with liver function parameters and moderately with HNA2. Baseline levels of HNA2 accurately predicted 30-day and 90-day survival in cirrhotic patients and this was confirmed in an external validation cohort.

CONCLUSIONS

Our results suggest that oxidative damage impairs binding properties of albumin. In advanced liver disease, reduced binding capacity of albumin site II is mainly related to impaired liver function. The plasma level of HNA2 is closely related to survival and may represent a novel biomarker for liver failure.

Selective plasma exchange with dialysis in patients with acute liver failure

Selective plasma exchange with dialysis is a blood purification therapy in which simple plasma exchange is performed using a selective membrane plasma separator while the dialysate flows out of the hollow fibers. To evaluate the effect of plasma exchange with dialysis, biochemical examination of the blood, for example, the oxidative stress regulation system and interleukin 18 levels, was performed in patients with acute liver failure. We studied four patients with acute liver failure in whom the therapy was performed (nine times in total). The degree of hepatic encephalopathy and interleukin 18 levels decreased significantly after treatment. However, total protein levels did not change significantly. The level of reactive oxygen species and total antioxidant capacity did not change significantly. Plasma exchange with dialysis may be a useful blood purification therapy in cases of acute liver failure in terms of the removal of water-soluble and albumin-bound toxins.

Redox albuminomics: oxidized albumin in human diseases

SIGNIFICANCE

Albumin is the major contributor to colloid oncotic pressure and also serves as an important carrier protein of many endogenous and exogenous molecules throughout the body. In blood and extravascular fluids, albumin is susceptible to different oxidative modifications, especially thiol oxidation and carbonylation. Because of its metal-binding properties and the redox properties of its Cys34 thiol, albumin displays an important antioxidant activity. As albumin is the predominant protein in most body fluids, its Cys34 represents the largest fraction of free thiols within body fluids.

RECENT ADVANCES

Evidence that albumin oxidation takes place in vivo has been reported only recently. Different redox proteomic, mass spectrometric, and chromatographic techniques have shown albumin redox modifications in various human pathophysiological conditions. As a whole, most data here presented demonstrate that massive albumin oxidation occurs in vivo in different biological fluids and, to some extent, that this process is correlated to organ dysfunction.

CRITICAL ISSUES

Recent reports suggest that the albumin redox state may serve as a global biomarker for the redox state in the body in various human diseases. However, further study is required to elucidate the exact relationship between albumin oxidation and pathology. In addition, it is unknown if some albumin oxidized forms may also have diagnostic uses.

FUTURE DIRECTIONS

Application of specific redox proteomics techniques for the characterization of oxidized albumin forms in screening studies is required. A further challenge will be to analyze how these oxidative albumin modifications are related to real impact to the body.

Effects of fractionated plasma separation and adsorption on survival in patients with acute-on-chronic liver failure

BACKGROUND & AIMS

Fractionated plasma separation and adsorption (FPSA) is an extracorporeal procedure that supports liver function by removing endogenous toxins that cause complications from acute-on-chronic liver failure (AOCLF). We performed a randomized trial to investigate survival of patients with AOCLF treated with FPSA.

METHODS

Patients with AOCLF were randomly assigned to groups given a combination of FPSA and standard medical therapy (SMT) (FPSA group, n = 77) or only SMT (SMT group, n = 68). The Prometheus liver support system was used to provide 8 to 11 rounds of FPSA (minimum of 4 hours each) for 3 weeks. Primary end points were survival probabilities at days 28 and 90, irrespective of liver transplantation.

RESULTS

Baseline clinical parameters and number of transplant patients were similar between study arms. Serum bilirubin level decreased significantly in the FPSA group but not in the SMT group. In an intention-to-treat analysis, the probabilities of survival on day 28 were 66% in the FPSA group and 63% in the SMT group (P = .70); on day 90, they were 47% and 38%, respectively (P = .35). Baseline factors independently associated with poor prognosis were high SOFA score, bleeding, female sex, spontaneous bacterial peritonitis, intermediate increases in serum creatinine concentration, and combination of alcoholic and viral etiology of liver disease. There were no differences between the 2 groups in the incidence of side effects.

CONCLUSIONS

Among all patients with AOCLF, extracorporeal liver support with FPSA does not increase the probability of survival. Further studies are needed to assess whether therapy might be beneficial in specific subsets of patients.

Monitoring oxidative stress in acute-on-chronic liver failure by advanced oxidation protein products

AIM

  Increased oxidative stress is important in the pathogenesis of acute-on-chronic liver failure (ACLF). This study aimed to investigate whether advanced oxidation protein products (AOPP) levels can monitor oxidative stress of ACLF patients. Furthermore, we aimed to study plasma exchange (PE) treatment and determine whether it can eliminate AOPP.

METHODS

  We measured AOPP levels in 50 ACLF patients, 30 patients with compensated liver cirrhosis (CR), 30 patients with chronic hepatitis B (CHB) and 50 healthy controls by spectrophotometric assay. AOPP concentrations were also measured before and after PE treatment in ACLF patients. As an apoptosis marker, serum cytokeratin 18 (CK18 M 30) levels were detected to investigate the relationship between AOPP and apoptosis in ACLF patients.

RESULTS

  Significantly higher AOPP levels at admission were found in patients with ACLF compared with CR, CHB and healthy controls (69.45 ± 29.04 µmol/L vs. 19.67 ± 7.02 µmol/L, 26.75 ± 5.21 µmol/L and 21.35 ± 6.15 µmol/L, respectively; P < 0.001). There was a positive relationship with total bilirubin, Child-Pugh, model for end-stage liver disease scores and CK18 M 30. In ACLF patients, AOPP levels were higher in non-survivors than survivors. An AOPP cut-off of 74.21 µmol/L was used for predicting poor prognosis. Multivariate Cox regression analysis demonstrated that AOPP were independent risk factors for prognosis. Dynamic change of AOPP levels associated with prognosis appeared earlier than total bilirubin. Following PE treatment, AOPP levels reduced to 34.65 ± 18.14 µmol/L (P < 0.001).

CONCLUSIONS

  Advanced oxidation protein products were suitable for monitoring the levels of oxidative stress in ACLF patients. Increased AOPP may serve as an important biological marker of worse outcome. In addition, PE therapy was effective in reducing AOPP.

Fractionated plasma separation and adsorption: current practice and future options

Fractionated plasma separation and adsorption (FPSA) is a method of albumin dialysis that is integrated into an extracorporeal liver support device (Prometheus(®)). This concept allows the effective removal of both protein-bound and water-soluble substances without the need for external albumin. Several studies comparing the in vivo extraction capacities of FPSA and molecular adsorbent recirculating system (MARS) concluded that detoxification by FPSA seems to be more effective than by MARS. Overall, FPSA therapy has been shown to be safe. Over the last few years, the anticoagulation protocol for FPSA therapy was optimised by using regional anticoagulation with citrate to avoid clotting of system components. Recently, the results of a large randomised-controlled multicentre trial (HELIOS) have been presented. Survival after 1 and 3 months was evaluated in 145 patients with acute-on-chronic liver failure comparing FPSA therapy with standard medical treatment versus standard medical treatment alone. There was no statistically significant survival benefit for patients undergoing FPSA therapy. However, patients with hepatorenal syndrome type I or MELD score >30 showed a significant survival benefit under FPSA in a predefined subgroup analysis. Furthermore, there have been promising results with FPSA in the treatment of refractory cholestatic pruritus. Regarding acute liver failure, only few data are currently available.

Acute-on-chronic liver failure: extracorporeal liver assist devices

PURPOSE OF REVIEW

Acute-on-chronic liver failure (ACLF), a syndrome precipitated by acute liver injury in patients with advanced cirrhosis, is associated with multiorgan dysfunction and high rates of mortality. Liver support systems have been developed in an attempt to improve survival of patients with ACLF by providing a bridge until recovery of the native liver function.

RECENT FINDINGS

Nonbiological devices such as molecular adsorbent recirculating system (MARS) and fractionated plasma separation and adsorption (Prometheus) are effective in improving severe hepatic encephalopathy and cholestasis, have good safety and tolerability profiles and are frequently employed in patients with ACLD; however, randomized controlled trials (RCTs) failed to show improvement in survival. Biologic devices that incorporate hepatic cells in bioreactors are also under development. Recent data from pilot studies suggested improvement in survival rates in some groups of patients with ACLF; however, their effect on patient survival in RCT is still unknown.

SUMMARY

Liver support systems are safe and well tolerated when used in management of patients with ACLF. Their use should continue in controlled clinical trials to explore their role in bridging patients to liver transplantation or recovery in well defined patient groups.

Device for continuous extracorporeal blood purification using target-specific metal nanomagnets

BACKGROUND

The present work illustrates how magnetic separation-based blood purification using ultra-strong iron nanomagnets can be implemented into an extracorporeal blood purification circuit. By this promising technique, today's blood purification may be extended to specifically filter high-molecular compounds without being limited by filter cut-offs or column surface saturation.

METHODS

Blood spiked with digoxin (small molecule drug) and interleukin-1β (inflammatory protein) was circulated ex vivo through a device composed of approved blood transfusion lines. Target-specific nanomagnets were continuously injected and subsequently recovered with the aid of a magnetic separator before recirculating the blood.

RESULTS

Magnetic blood purification was successfully carried out under flow conditions: already in single-pass experiments, removal efficiencies reached values of 75 and 40% for digoxin and interleukin-1β, respectively. Circulating 0.5 L of digoxin-intoxicated blood in a closed loop, digoxin concentration was decreased from initially toxic to therapeutic concentrations within 30 min and purification extents of 90% were achieved after 1.5 h.

CONCLUSIONS

Magnetic separation can be successfully implemented into an extracorporeal blood purification device. Simultaneous and specific filtering of high-molecular compounds may offer promising new therapeutic tools for the future treatment of complex diseases, such as sepsis and autoimmune disorders.

Redox state of human serum albumin in terms of cysteine-34 in health and disease

Albumin, the main protein in plasma, is prone to different mechanisms of oxidative modification since extracellular fluids contain only small amounts of antioxidant enzymes. The redox state of cysteine-34 of human albumin defines three fractions which allow to monitor albumin oxidation: mercaptalbumin with a free thiol group, nonmercaptalbumin1 containing a disulfide, and nonmercaptalbumin2 with a sulfinic or sulfonic acid group. These fractions can be separated by HPLC and detected with UV or fluorescence detection. The method is very rugged and only simple sample preparation is needed. It has been used to demonstrate albumin oxidation during exercise, aging, and pathologies like diabetes, liver disease, or renal disease. Problems may arise when high endogenous concentrations of bilirubin or certain drugs are present. The redox state of albumin shows high variability and is hence a valuable tool for the investigation of reversible and irreversible modification of plasma protein.