Albumin Homodimers in Patients with Cirrhosis: Clinical and Prognostic Relevance of a Novel Identified Structural Alteration of the Molecule

Oxidized Melanoma Antigens Promote Activation and Proliferation of Cytotoxic T-Cell Subpopulations

Increasing evidence suggests the role of reactive oxygen and nitrogen species (RONS) in regulating antitumor immune effects and immunosuppression. RONS modify biomolecules and induce oxidative post-translational modifications (oxPTM) on proteins that can alarm phagocytes. However, it is unclear if and how protein oxidation by technical means could be a strategy to foster antitumor immunity and therapy. To this end, cold gas plasma technology producing various RONS simultaneously to oxidize the two melanoma-associated antigens MART and PMEL is utilized. Cold plasma-oxidized MART (oxMART) and PMEL (oxPMEL) are heavily decorated with oxPTMs as determined by mass spectrometry. Immunization with oxidized MART or PMEL vaccines prior to challenge with viable melanoma cells correlated with significant changes in cytokine secretion and altered T-cell differentiation of tumor-infiltrated leukocytes (TILs). oxMART promoted the activity of cytotoxic central memory T-cells, while oxPMEL led to increased proliferation of cytotoxic effector T-cells. Similar T-cell results are observed after incubating splenocytes of tumor-bearing mice with B16F10 melanoma cells. This study, for the first time, provides evidence of the importance of oxidative modifications of two melanoma-associated antigens in eliciting anticancer immunity.

Efficacy of albumin use in decompensated cirrhosis and real-world adoption in Australia

The current treatment approach to patients with liver cirrhosis relies on the individual management of complications. Consequently, there is an unmet need for an overall therapeutic strategy for primary and secondary prevention of complications. The clinical potential of long-term albumin infusions supported by recent clinical trials has expanded its indications and holds promise to transform the management and secondary prevention of cirrhosis-related complications. This renewed interest in albumin comes with inherent controversies, compounding challenges and pressing need for rigorous evaluation of its clinical potential to capitalize on its therapeutic breakthroughs. Australia is among a few countries worldwide to adopt outpatient human albumin infusion. Here, we summarize currently available evidence of the potential benefits of human albumin for the management of multiple liver cirrhosis-related complications and discuss key challenges for wide application of long-term albumin administration strategy in Australian clinical practice. Australian Gastroenterological week (AGW), organised by the Gastroenterological Society of Australia (GESA), was held between 9-11 September 2022. A panel of hepatologists, advanced liver nurses and one haematologist, were invited to a roundtable meeting to discuss the use of long-term albumin infusions for liver cirrhosis. management in Australia. In this review, we summarise the proceedings of this meeting in context of the current literature.

Early Graft Failure After Living-Donor Liver Transplant

BACKGROUND

Living-donor liver transplantation (LDLT) has been increasing in the USA. While data exist on longer-term patient and graft outcomes, a contemporary analysis of short-term outcomes is needed.

AIM

Evaluate short-term (30-day) graft failure rates and identify predictors associated with these outcomes.

METHODS

Adult (≥ 18) LDLT recipients from 01/2004 to 12/2021 were analyzed from the United States Scientific Registry of Transplant Recipients. Graft status at 30 days was assessed with graft failure defined as retransplantation or death. Comparison of continuous and categorical variables was performed and a multivariable logistic regression was used to identify risk factors of early graft failure.

RESULTS

During the study period, 4544 LDLTs were performed with a graft failure rate of 3.4% (155) at 30 days. Grafts from male donors (aOR: 0.63, CI 0.44-0.89), right lobe grafts (aOR: 0.40, CI 0.27-0.61), recipients aged > 60 years (aOR: 0.52, CI 0.32-0.86), and higher recipient albumin (aOR: 0.73, CI 0.57-0.93) were associated with superior early graft outcomes, whereas Asian recipient race (vs. White; aOR: 3.75, CI 1.98-7.10) and a history of recipient PVT (aOR: 2.7, CI 1.52-4.78) were associated with inferior outcomes. LDLTs performed during the most recent 2016-2021 period (compared to 2004-2009 and 2010-2015) resulted in significantly superior outcomes (aOR: 0.45, p < 0.001).

CONCLUSION

Our study demonstrates that while short-term adult LDLT graft failure is uncommon, there are opportunities for optimizing outcomes by prioritizing right lobe donation, improving candidate nutritional status, and careful pre-transplant risk assessment of candidates with known PVT. Notably, a period effect exists whereby increased LDLT experience in the most recent era correlated with improved outcomes.

Albumin, an interesting and functionally diverse protein, varies from 'native' to 'effective' (Review)

Human serum albumins (HSAs) are synthesized in the liver and are the most abundant proteins in plasma of healthy human. They play an important role in the pathophysiological processes of the liver and even the whole organism. Previous studies have mainly focused on the regulation of HSAs' expression. However, with the progress of research in recent years, it has been found that the content of circulating albumin cannot fully reflect the biological function of albumin itself. Given the aforementioned fact, the concept of serum 'effective albumin concentration' has been proposed. It refers to the content of albumin that is structurally and functionally intact. Alterations in the molecular structure and function of albumin have been reported in a variety of diseases, including liver disease. Moreover, these changes have been verified to affect the progression of oxidative stress‑related diseases. However, the link between albumin structure and function has not been fully elaborated, and the mechanisms by which different forms of albumin affect disease also need to be further investigated. In this context, the present review mainly expounded the biological characteristics and functions of albumin, summarized the different types of post‑translational modification of albumin, and discussed their functional changes and possible mechanisms in non‑alcoholic fatty liver disease, alcoholic hepatitis, viral hepatitis and different stages of cirrhosis. This will help to improve understanding of the role of albumin in disease development and provide a more comprehensive physiological basis for it in disease treatment.

Absolute Quantification of Human Serum Albumin Isoforms by Internal Calibration Based on a Top-Down LC-MS Approach

Well-characterized biomarkers using reliable quantitative methods are essential for the management of various pathologies such as diabetes, kidney, and liver diseases. Human serum albumin (HSA) isoforms are gaining interest as biomarkers of advanced liver pathologies. In view of the structural alterations observed for HSA, insights into its isoforms are required to establish them as reliable biomarkers. Therefore, a robust absolute quantification method seems necessary. In this study, we developed and validated a far more advanced top-down liquid chromatography-mass spectrometry (LC-MS) method for the absolute quantification of HSA isoforms, using myoglobin (Mb) as an internal standard for quantification and for mass recalibration. Two different quantification approaches were investigated based on peak integration from the deconvoluted spectrum and extracted ion chromatogram (XIC). The protein mixture human serum albumin/myoglobin eluted in well-shaped separated peaks. Mb allowed a systematic mass recalibration for every sample, resulting in extremely low mass deviations compared to conventional deconvolution-based methods. In total, eight HSA isoforms of interest were quantified. Specific-isoform calibration curves showing good linearity were obtained by using the deconvoluted peaks. Noticeably, the HSA ionization behavior appeared to be isoform-dependent, suggesting that the use of an enriched isoform solution as a calibration standard for absolute quantification studies of HSA isoforms is necessary. Good repeatability, reproducibility, and accuracy were observed, with better sensitivity for samples with low albumin concentrations compared to routine biochemical assays. With a relatively simple workflow, the application of this method for absolute quantification shows great potential, especially for HSA isoform studies in a clinical context, where a high-throughput method and sensitivity are needed.

Early detection of liver injuries by the Serum enhanced binding test sensitive to albumin post-transcriptional modifications

Early and sensitive biomarkers of liver dysfunction and drug-induced liver injury (DILI) are still needed, both for patient care and drug development. We developed the Serum Enhanced Binding (SEB) test to reveal post-transcriptional modifications (PTMs) of human serum albumin resulting from hepatocyte dysfunctions and further evaluated its performance in an animal model. The SEB test consists in spiking serum ex-vivo with ligands having specific binding sites related to the most relevant albumin PTMs and measuring their unbound fraction. To explore the hypothesis that albumin PTMs occur early during liver injury and can also be detected by the SEB test, we induced hepatotoxicity in male albino Wistar rats by administering high daily doses of ethanol and CCl4 over several days. Blood was collected for characterization and quantification of albumin isoforms by high-resolution mass spectrometry, for classical biochemical analyses as well as to apply the SEB test. In the exposed rats, the appearance of albumin isoforms paralleled the positivity of the SEB test ligands and histological injuries. These were observed as early as D3 in the Ethanol and CCl4 groups, whereas the classical liver tests (ALT, AST, PAL) significantly increased only at D7. The behavior of several ligands was supported by structural and molecular simulation analysis. The SEB test and albumin isoforms revealed hepatocyte damage early, before the current biochemical biomarkers. The SEB test should be easier to implement in the clinics than albumin isoform profiling.

Alcohol spiked with zolpidem and midazolam potentiates inflammation, oxidative stress and organ damage in a mouse model

PURPOSE

Crime-related spiking of alcoholic drinks with prescription drugs is quite common and has been happening for centuries. This study, therefore, evaluated the effects of oral administration of alcohol spiked with the zolpidem and midazolam potent sedatives on inflammation, oxidative stress and various organ damage in male Swiss albino mice.

METHODS

Mice were randomly assigned into six treatment groups; the first group constituted the normal control, the second group received 50 mg/kg body weight of zolpidem only, the third group received 50 mg/kg body weight zolpidem dissolved in 5 g/kg alcohol, the fourth group received 50 mg/kg midazolam only, the fifth group received midazolam (50 mg/kg) dissolved in 5 g/kg alcohol and the sixth group received 5 g/kg alcohol.

RESULTS

Alcohol-induced significant reduction in neurological function and altered blood hematological indicators. Such neurological impairment and negative effects on blood were exacerbated in mice administered with spiked alcohol. Additionally, midazolam and zolpidem enhanced alcohol-driven elevation of liver function markers; the serum aspartate aminotransferase (AST), alanine aminotransferase (ALT) gamma glutamyltransferase (GGT), total bilirubin and alkaline phosphatase. Exposure to alcohol and/or spiked alcohol led to significant augmentation of nitric oxide and malonaldehyde, with concomitant depletion of liver glutathione (GSH) levels. Similarly, serum levels of pro-inflammatory cytokines tumor necrosis factor alpha and interferon-gamma were increased by co-exposure with midazolam or zolpidem. Alcohol-induced hepatotoxicity and nephrotoxicity were amplified by exposure to alcohol spiked with midazolam/zolpidem.

CONCLUSION

Exposure to alcohol spiked with midazolam or zolpidem appears to exacerbate neurological deficits, inflammation, oxidative stress, and organ damage.

Albumin administration in internal medicine: A journey between effectiveness and futility

Albumin is the most abundant circulating protein and provides about 70% of the plasma oncotic power. The molecule also carries many other biological functions (binding, transport and detoxification of endogenous and exogenous compounds, antioxidation, and modulation of inflammatory and immune responses). Hypoalbuminemia is a frequent finding in many diseases, representing usually only a biomarker of poor prognosis rather than a primary pathophysiological event. Despite that, albumin is prescribed in many conditions based on the assumption that correction of hypoalbuminemia would lead to clinical benefits for the patients. Unfortunately, many of these indications are not supported by scientific evidence (or have been even disproved), so that a large part of albumin use is nowadays still inappropriate. Decompensated cirrhosis is the clinical area where albumin administration has been extensively studied and solid recommendations can be made. Besides prevention and treatment of acute complications, long-term albumin administration in patients with ascites has emerged in the last decade has a potential new disease-modifying treatment. In non-hepatological settings, albumin is widely used for fluid resuscitation in sepsis and critical illnesses, with no clear superiority over crystalloids. In many other conditions, scientific evidence supporting albumin prescription is weak or even absent. Thus, given its high cost and limited availability, action is needed to avoid the use of albumin for inappropriate and futile indications to ensure its availability in those conditions for which albumin has been demonstrated to have a real effectiveness and an advantage for the patient.

Review article: Emerging and current management of acute-on-chronic liver failure

BACKGROUND

Acute-on-chronic liver failure (ACLF) is a clinically and pathophysiologically distinct condition from acutely decompensated cirrhosis and is characterised by systemic inflammation, extrahepatic organ failure, and high short-term mortality.

AIMS

To provide a narrative review of the diagnostic criteria, prognosis, epidemiology, and general management principles of ACLF. Four specific interventions that are explored in detail are intravenous albumin, extracorporeal liver assist devices, granulocyte-colony stimulating factor, and liver transplantation.

METHODS

We searched PubMed and Cochrane databases for articles published up to July 2023.

RESULTS

Approximately 35% of hospital inpatients with decompensated cirrhosis have ACLF. There is significant heterogeneity in the criteria used to diagnose ACLF; different definitions identify different phenotypes with varying mortality. Criteria established by the European Association for the Study of the Liver were developed in prospective patient cohorts and are, to-date, the most well validated internationally. Systemic haemodynamic instability, renal dysfunction, coagulopathy, neurological dysfunction, and respiratory failure are key considerations when managing ACLF in the intensive care unit. Apart from liver transplantation, there are no accepted evidence-based treatments for ACLF, but several different approaches are under investigation.

CONCLUSION

The recognition of ACLF as a distinct entity from acutely decompensated cirrhosis has allowed for better patient stratification in clinical settings, facilitating earlier engagement with the intensive care unit and liver transplantation teams. Research priorities over the next decade should focus on exploring novel treatment strategies with a particular focus on which, when, and how patients with ACLF should be treated.

Semi-synthetic human albumin isoforms: Production, structure, binding capacities and influence on a routine laboratory test

Human Serum Albumin (HSA) undergoes Post-Translational-Modifications (PTMs) leading to isoforms affecting its oncotic and non-oncotic properties. HSA is comprised of several isoforms whose abundance may vary with pathologies such as diabetes, kidney and liver diseases. Studying their impact separately may help to understand their sources and potential pathogenicity and further their evaluation as biomarkers. The present study examined semi-synthetic HSA isoforms to investigate independently their structure by means of advanced mass spectrometry techniques (LC-TOF-MS and ICP-MS), influence on the HSA binding/antioxidant activities using a binding capacity test, and potential impact on albumin quantification by a routine immunoturbidimetric assay. Applying different chemical reactions to a commercial HSA solution, we obtained different solutions enriched up to 53 % of native HSA, 78 % of acetylated HSA, 71 % of cysteinylated HSA, 94 % of oxidized HSA, 58 % of nitrosylated HSA and 96 % of glycated HSA, respectively. Moreover, the semi-synthetic isoforms showed differently altered binding capacities for a panel of ligands (Cu, Cd, Au, Ds and L-T4). Furthermore, immunoturbidimetry was found to be insensitive to the presence and abundance of the different isoforms. The fully characterized semi synthetic HSA isoforms obtained should be useful to further investigate their pathogenicity and potential roles as biomarkers.

Controversies regarding albumin therapy in cirrhosis

Albumin is the most abundant protein in the human body and is synthetized exclusively by the liver. Therefore, serum albumin levels are reduced in acute and/or chronic liver disease. In cirrhosis, low levels of albumin predict the outcome. In advanced cirrhosis, the quality of albumin is decreased due to high oxidative stress and a proinflammatory state. Therefore, the administration of i.v. albumin would seem to be of pathophysiological relevance and benefit. Yet, the questions that remain are who, when, how much, and how often. While albumin infusion is recommended after large-volume paracentesis, at diagnosis of spontaneous bacterial peritonitis, in acute kidney injury, and in hepatorenal syndrome, the amount and schedule of albumin to be administered require refinement, particularly given complications related to volume overload that have become increasingly apparent. Other indications for albumin such as infections other than spontaneous bacterial peritonitis, hyponatremia, HE, prevention of poor outcomes in hospitalized, and in outpatients with cirrhosis are still debated. The results of studies in these settings are either negative, controversial, or inconclusive. This sheds some doubts regarding the use of albumin as a "one size fits all" strategy. The indication and patient selection are crucial and not always intuitive. The amount and frequency also seem to play a role in the success or failure of albumin. This review will critically discuss the evidence and underline areas where there are indications for albumin use and others where evidence is still insufficient and will have to await the development/results of randomized controlled trials.

Posttranslational-modifications of human-serum-albumin analysis by a top-down approach validated by a comprehensive bottom-up analysis

The posttranslational modifications (PTM) of human serum albumin (HSA) can result in the development of isoforms that have been identified as potential biomarkers for advanced hepatic diseases. However, previous approaches using top-down (TD) analysis to identify isoforms based on molecular weight may have resulted in misidentifications. The nature of the identified isoforms has never been confirmed in previous works. Here, we aimed to critically evaluate TD for the characterization and determination of HSA isoforms in patients and make an inventory of HSA-PTM. Serum samples from control subjects and patients with liver dysfunctions were analyzed using both top-down (TD) and bottom-up (BU) approaches. TD analysis involved using a LC-TOF-MS system to obtain a multicharged spectrum of HSA, which was deconvoluted to identify isoforms. Spectra were then used for relative quantitation analysis of albumin isoform abundances based on trapezoidal integration. For BU analysis, serums were reduced +/- alkylated, digested with trypsin and analyzed in the Q-TOF, data-dependent acquisition (DDA) mode to generate a SWATH-MS high-resolution mass spectral library of all HSA peptides. Tryptic digests of another set of serum samples were then analyzed using data-independent acquisition (DIA) mode to confirm the presence of HSA isoforms and their modification sites. TD detected 15 isoforms corresponding to various modifications, including glycation, cysteinylation, nitrosylation, and oxidation (di- and tri-). In BU, the spectral library containing 127 peptides allowed for the characterization of the important isoforms with their modified sites, including some modifications that were only characterized in BU (carbamylation, deamidation, and amino-acid substitution). The method used for determining isoforms offered acceptable reproducibility (intra-/inter-assay CVs < 15%) for all isoforms present at relative abundances higher than 2%. Overall, the study found that several isoforms could be missed or misidentified by TD. However, all HSA isoforms identified by TD and reported to be relevant in liver dysfunctions were confirmed by BU. This critical evaluation of TD approach helped design an adequate and reliable method for the characterization of HSA isoforms in patients and offers the possibility to estimate isoform abundances within 3 min. These findings have significant implications for the diagnosis and treatment of liver dysfunctions.

Structural changes of proteins in liver cirrhosis and consequential changes in their function

The liver is the site of synthesis of the majority of circulating proteins. Besides initial polypeptide synthesis, sophisticated machinery is involved in the further processing of proteins by removing parts of them and/or adding functional groups and small molecules tailoring the final molecule to suit its physiological purpose. Posttranslational modifications (PTMs) design a network of molecules with the common protein ancestor but with slightly or considerably varying activity/localization/purpose. PTMs can change under pathological conditions, giving rise to aberrant or overmodified proteins. Undesired changes in the structure of proteins most often accompany undesired changes in their function, such as reduced activity or the appearance of new effects. Proper protein processing is essential for the reactions in living beings and crucial for the overall quality control. Modifications that occur on proteins synthesized in the liver whose PTMs are cirrhosis-related are oxidation, nitration, glycosylation, acetylation, and ubiquitination. Some of them predominantly affect proteins that remain in liver cells, whereas others predominantly occur on proteins that leave the liver or originate from other tissues and perform their function in the circulation. Altered PTMs of certain proteins are potential candidates as biomarkers of liver-related diseases, including cirrhosis. This review will focus on PTMs on proteins whose structural changes in cirrhosis exert or are suspected to exert the most serious functional consequences.

Determination of Effective Albumin in Patients With Decompensated Cirrhosis: Clinical and Prognostic Implications

BACKGROUND AND AIMS

Circulating albumin in cirrhosis can be dysfunctional because of accumulating structural damages, leading to the concept of effective albumin concentration (eAlb), referring to the albumin portion presenting structural and functional integrity. We aimed to estimate eAlb in patients with decompensated cirrhosis and analyze its relationships with albumin function and clinical outcomes as compared to total albumin concentration (tAlb).

APPROACH AND RESULTS

We evaluated 319 patients with cirrhosis hospitalized for acute decompensation (AD) with and without acute-on-chronic liver failure (ACLF) and 18 age- and sex-comparable outpatients with compensated cirrhosis. tAlb was quantified by standard assay, whereas eAlb was estimated combining liquid chromatography/electrospray ionization/mass spectrometry and standard methods. Albumin binding and detoxification efficiency were evaluated by electron paramagnetic resonance analysis. Circulating albumin in patients with decompensated cirrhosis displayed multiple structural abnormalities, with reversible oxidation and glycation being the most frequent. As a result, eAlb progressively declined with the worsening of cirrhosis and was superior to tAlb in stratifying patients between compensated cirrhosis, AD, and ACLF, as well as patients with and without complications. Moreover, eAlb, but not tAlb, was closely associated with binding capacities in ACLF. Finally, eAlb at admission predicted the occurrence of ACLF within 30 days and mortality at 90 days better than tAlb.

CONCLUSIONS

This large, observational study provides the evidence in patients with decompensated cirrhosis that eAlb can be quantified and differentiated from tAlb routinely measured in clinical practice. As compared to tAlb, eAlb is more closely associated with disease severity and albumin dysfunction and carries a greater prognostic power. These results prompt future research assessing eAlb as a biomarker for predicting prognosis and treatment response.

Association of Low Serum Albumin Level with Higher Hepatocellular Carcinoma Recurrence in Patients with Hepatitis B Virus Pre-S2 Mutant after Curative Surgical Resection

Hepatocellular carcinoma (HCC) is, globally, one of the most prevalent and deadly human cancers; despite curative surgical resection, its high recurrence rate after surgery remains a large threat, resulting in poor patient survival. The hepatitis B virus (HBV) pre-S2 mutant that harbors deletions spanning the pre-S2 gene segment has emerged as an important oncoprotein for HCC development and a valuable prognostic biomarker for HCC recurrence; however, its relationship with clinicopathological factors is largely unexplored. In this study, the correlation of the deletion spanning the pre-S2 gene segment with clinicopathological factors and the association of such correlation with HCC recurrence after curative surgical resection were examined in HBV-related HCC patients. Inverse correlation between serum albumin level and the deletion spanning the pre-S2 gene segment was identified. HCC patients with the presence of the deletion spanning the pre-S2 gene segment and a low serum albumin level were associated with higher HCC recurrence than patients with either factor alone or neither factor were. Moreover, a combination of the serum albumin level and the deletion spanning the pre-S2 gene segment exhibited better performance than that of either factor alone in predicting HCC recurrence. Collectively, this study shows an association of low serum albumin level with pre-S2 mutant-positive HCC patients, and validates the prognostic value of this association in identifying patients with higher HCC recurrence after curative surgical resection.

Pathophysiology of decompensated cirrhosis: Portal hypertension, circulatory dysfunction, inflammation, metabolism and mitochondrial dysfunction

Patients with acutely decompensated cirrhosis have a dismal prognosis and frequently progress to acute-on-chronic liver failure, which is characterised by hepatic and extrahepatic organ failure(s). The pathomechanisms involved in decompensation and disease progression are still not well understood, and as specific disease-modifying treatments do not exist, research to identify novel therapeutic targets is of the utmost importance. This review amalgamates the latest knowledge on disease mechanisms that lead to tissue injury and extrahepatic organ failure - such as systemic inflammation, mitochondrial dysfunction, oxidative stress and metabolic changes - and marries these with the classical paradigms of acute decompensation to form a single paradigm. With this detailed breakdown of pathomechanisms, we identify areas for future research. Novel disease-modifying strategies that break the vicious cycle are urgently required to improve patient outcomes.

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.

Optimal Management of Cirrhotic Ascites: A Review for Internal Medicine Physicians

Clinical history of liver cirrhosis is characterised by two phases: the asymptomatic phase, also termed 'compensated cirrhosis', and the phase of complications due to the development of portal hypertension and liver dysfunction, also termed 'decompensated cirrhosis', in which patients may develop ascites, the most frequent and clinically relevant complication of liver cirrhosis. Ascites can be classified into uncomplicated and complicated according to the development of refractoriness, spontaneous bacterial peritonitis (SBP) or the association with hepatorenal syndrome (HRS). In this narrative review, we will extensively discuss the optimal pharmacological and non-pharmacological management of cirrhotic ascites with the aim to offer an updated practical guide to Internal Medicine physicians. According to the amount of fluid in the abdominal cavity, uncomplicated ascites is graded from 1 to 3, and the cornerstone of its management consists of restriction of salt intake, diuretics and large-volume paracentesis (LVP); in recent years, long-term administration of human albumin has acquired a new interesting role. Refractory ascites is primarily managed with LVP and transjugular intrahepatic portosystemic shunt (TIPS) placement in selected patients. The occurrence of renal impairment, especially HRS, worsens the prognosis of patients with cirrhotic ascites and deserves a specific treatment. Also, the management of SBP faces the rising and alarming spread of antibiotic resistance. Hepatic hydrothorax may even complicate the course of the disease and its management is a challenge. Last but not least, liver transplantation (LT) is the ultimate and more effective measure to offer to patients with cirrhotic ascites, particularly when complications occur.

Albumin Administration is Efficacious in the Management of Patients with Cirrhosis: A Systematic Review of the Literature

The use of albumin in patients with cirrhosis has been extensively discussed over recent years. Current treatment approaches depend on targeting related complications, aiming to treat and/or prevent circulatory dysfunction, bacterial infections and multi-organ failure. Albumin has been shown to prolong survival and reduce complications in patients with cirrhosis. This review aims to ascertain whether the use of albumin is justified in patients with cirrhosis. A systematic review of randomized controlled trials (RCTs) and meta-analyses evaluating albumin use in patients with cirrhosis published between 1985 and February 2020 was conducted; the quality and risk of bias of the included studies were assessed. In total, 45 RCTs and 10 meta-analyses were included. Based on the included evidence, albumin is superior at preventing and controlling the incidence of cirrhosis complications vs other plasma expanders. Recent studies reported that long-term albumin administration to patients with decompensated cirrhosis improves survival with a 38% reduction in the mortality hazard ratio compared with standard medical treatment alone. Albumin infusions are justified for routine use in patients with cirrhosis, and the use of albumin either alone or in combination with other treatments leads to clinical benefits. Long-term administration of albumin should be considered in some patients.

Hemodynamic and Systemic Effects of Albumin in Patients with Advanced Liver Disease

Purpose of Review

Albumin administration is recommended to prevent or treat specific complications of decompensated cirrhosis based on its capacity to expand plasma volume. However, the molecule also has many other biological properties that are unrelated to the oncotic activity. The purpose of this review is to examine the hemodynamic and systemic effects of albumin administration in patients with decompensated cirrhosis.

Recent Findings

Besides plasma expansion, albumin appears to act against inflammation, facilitate immunocompetence, and improve cardiac and endothelial function, thus antagonizing critical steps in the pathophysiological cascade underlying decompensated cirrhosis.

Summary

Increasing knowledge of the pathophysiological mechanisms of the disease, as well the pleiotropic properties of the molecule, provides the rationale for considering albumin as a multi-target disease-modifying agent in decompensated cirrhosis. Both oncotic and non-oncotic properties likely concur with the clinical benefits of long-term albumin administration recently demonstrated in these patients.

Albumin in decompensated cirrhosis: new concepts and perspectives

The pathophysiological background of decompensated cirrhosis is characterised by a systemic proinflammatory and pro-oxidant milieu that plays a major role in the development of multiorgan dysfunction. Such abnormality is mainly due to the systemic spread of bacteria and/or bacterial products from the gut and danger-associated molecular patterns from the diseased liver triggering the release of proinflammatory mediators by activating immune cells. The exacerbation of these processes underlies the development of acute-on-chronic liver failure. A further mechanism promoting multiorgan dysfunction and failure likely consists with a mitochondrial oxidative phosphorylation dysfunction responsible for systemic cellular energy crisis. The systemic proinflammatory and pro-oxidant state of patients with decompensated cirrhosis is also responsible for structural and functional changes in the albumin molecule, which spoil its pleiotropic non-oncotic properties such as antioxidant, scavenging, immune-modulating and endothelium protective functions. The knowledge of these abnormalities provides novel targets for mechanistic treatments. In this respect, the oncotic and non-oncotic properties of albumin make it a potential multitarget agent. This would expand the well-established indications to the use of albumin in decompensated cirrhosis, which mainly aim at improving effective volaemia or preventing its deterioration. Evidence has been recently provided that long-term albumin administration to patients with cirrhosis and ascites improves survival, prevents complications, eases the management of ascites and reduces hospitalisations. However, variant results indicate that further investigations are needed, aiming at confirming the beneficial effects of albumin, clarifying its optimal dosage and administration schedule and identify patients who would benefit most from long-term albumin administration.

Fluid Biomarkers for Predicting the Prognosis of Liver Cirrhosis

Liver cirrhosis is the terminal stage of most chronic liver conditions, with a high risk of mortality. Careful evaluation of the prognosis of cirrhotic patients and providing precise management are crucial to reduce the risk of mortality. Although the liver biopsy and hepatic venous pressure gradient (HVPG) can efficiently evaluate the prognosis of cirrhotic patients, their application is limited due to the invasion procedures. Child-Pugh score and the model for end-stage liver disease (MELD) score had been widely used in the assessment of cirrhotic prognosis, but the defects of subjective variable application in Child-Pugh score and unsuitability to all phases of liver cirrhosis in MELD score limit their prognostic values. In recent years, continuous efforts have been made to investigate the prognostic value of body fluid biomarkers for cirrhotic patients, and promising results have been reported. Since the collection of fluid specimens is easy, noninvasive, and repeatable, fluid biomarkers can be ideal indicators to predict the prognosis of cirrhosis. Here, we reviewed noninvasive fluid biomarkers in different prognostic functions, including the prediction of survival and complication development.

Effect of Cu2+ and Zn2+ ions on human serum albumin interaction with plasma unsaturated fatty acids

Human serum albumin (HSA) serves as a depot and carrier of multiple unrelated ligands including several participants of the pathogenesis of Alzheimer's disease (AD), such as amyloid β peptide (Aβ), Zn²⁺/Cu²⁺ ions, docosahexaenoic (DHA), linoleic (LA), and oleic (OA) acids. To explore the interplay between HSA interaction with Zn²⁺/Cu²⁺ and the plasma unsaturated fatty acids (DHA, LA, OA, and arachidonic acid (ArA)), we have studied the metal dependence of the fatty acid (FA) binding capacity of HSA (n_max) and structural consequences of the HSA-FA interactions. HSA loading with Zn²⁺ decreases n_max value by 0.3-1.5, while its saturation with Cu²⁺ causes the FA-dependent n_max changes by up to 0.9. The Cu²⁺-induced decline in n_max value for DHA is due to conformational rearrangements in HSA molecule. In other cases, the changes in n_max are attributed to steric hindarance/facilitation of the HSA-FA interaction because of the protein multimerization/monomerization, as confirmed by chemical crosslinking. The surface hydrophobicity of HSA is Cu²⁺-, Zn²⁺-, and FA-dependent and decreases upon the FA binding, according to bis-ANS fluorescence data. Overall, Zn²⁺ or Cu²⁺ binding selectively affect HSA interaction with the FAs studied, in part due to changes in quaternary structure of the protein.

Pro: The Role of Albumin in Pre-Liver Transplant Management

The wait-list mortality of patients with decompensated cirrhosis awaiting liver transplantation remains elevated due to the occurrence of complications. Etiologic treatments improve patient survival and lower the incidence of complications when applied in compensated cirrhosis, but a decompensated disease does not improve or even progress despite a response to therapy in a substantial number of patients. Thus, disease-modifying treatments that reduce the incidence of complications and improve survival are most needed. Such treatments should be able to counteract one or possibly more pathophysiological mechanisms and thus lead to the proinflammatory and pro-oxidant milieu that characterizes decompensated cirrhosis. In this respect, albumin represents a potentially ideal agent. In fact, besides its ability to expand plasma volume, albumin possesses nononcotic properties, exerting potent antioxidant and immune-modulating effects. Recent studies have assessed the effect of longterm albumin administration in decompensated cirrhosis. Although the results of these studies may appear conflicting, their analyses suggest that albumin, if given in a sufficient amount and for a sufficient duration, can significantly reduce the incidence of life-threatening complications of cirrhosis and patient mortality. For these reasons, we favor albumin administration to patients with decompensated cirrhosis wait-listed for liver transplantation.

Novel perspectives in the management of decompensated cirrhosis

The current approaches to the management of patients with decompensated cirrhosis are based on targeted strategies aimed at preventing or treating specific complications of the disease. The improved knowledge of the pathophysiological background of advanced cirrhosis, represented by a sustained systemic inflammation strictly linked to a circulatory dysfunction, provides a novel paradigm for the management of these patients, with the ambitious target of modifying the course of the disease by preventing the onset of complications and multiorgan failure; these interventions will eventually improve patients' quality of life, prolong survival and reduce health-care costs. Besides aetiological treatments, these goals could be achieved by persistently antagonizing key pathophysiological events, such as portal hypertension, abnormal bacterial translocation from the gut, liver damage, systemic inflammation, circulatory dysfunction and altered immunological responses. Interestingly, in addition to strategies based on new therapeutic agents, these targets can be tackled by employing drugs that are already used in patients with cirrhosis for different indications or in other clinical settings, including non-absorbable oral antibiotics, non-selective β-blockers, human albumin and statins. The scope of the present Review includes reporting updated information on the treatments that promise to influence the course of advanced cirrhosis and thus act as disease-modifying agents.

New Insights About Albumin and Liver Disease

Decompensated liver cirrhosis has a dismal prognosis, with an overall survival of 2-4 years, which is worse than for many oncological diseases. Albumin is an important tool in the management of patients with cirrhosis, since it decreases for less than half the risk for post-paracentesis cardiocirculatory dysfunction and mortality associated with spontaneous bacterial infection, as well as, it triplicates the response to terlipressin in patients with hepatorenal syndrome. Recently, research on albumin has been a hot topic, with important new insights such as the characterization of the pleiotropic effects of albumin (which surpass its oncotic properties) and the concept of effective albumin concentration. In fact, patients with liver cirrhosis present posttranslational modifications on albumin that compromises its function. Those modified albumin forms were proved to have prognostic value and its knowledge may change the paradigm of albumin treatment. In this review, we critically summarize the latest evidence on the potential benefits of albumin in patients with end-stage liver disease.

Non-oncotic properties of albumin. A multidisciplinary vision about the implications for critically ill patients

INTRODUCTION

Effective resuscitation with human albumin solutions is achieved with less fluid than with crystalloid solutions. However, the role of albumin in today's critical care unit is also linked to its multiple pharmacological effects. Areas covered: The potential clinical benefits of albumin in select populations of critically ill patients like sepsis seem related to immunomodulatory and anti-inflammatory effects, antibiotic transportation and endothelial stabilization. Albumin transports many drugs used in critically ill patients. Such binding to albumin is frequently lessened in critically ill patients with hypoalbuminemia. These changes could result in sub-optimal treatment. Albumin has immunomodulatory capacity by binding several bacterial products. Albumin also influences vascular integrity, contributing to the maintenance of the normal capillary permeability. Moreover, the albumin molecule encompasses several antioxidant properties, thereby significantly reducing re-oxygenation injury, which is especially important in sepsis. In fact, most studies of albumin administration are a combination of a degree of resuscitation with a degree of maintenance or supplementation of albumin. Expert commentary: The potential clinical benefits of the use of albumin in selected critically ill patients such as sepsis seem related to its immunomodulatory and anti-inflammatory effects, antioxidant properties, antibiotic transportation and endothelial stabilization. Additional studies are warranted to further elucidate the underlying physiologic and molecular rationale.

Structural and functional integrity of human serum albumin: Analytical approaches and clinical relevance in patients with liver cirrhosis

Human serum albumin (HSA) is the most abundant circulating plasma protein. Besides a significant contribution to the osmotic pressure, it is also involved in the fine regulation of many other physiological processes, including the balance of the redox state, the inflammatory and/or immunological responses, and the pharmacokinetic and pharmacodynamics of many drugs. Growing evidence suggests that HSA undergoes structural and functional damage in diseases characterized by an enhanced systemic inflammatory response and oxidative stress, as it occurs in chronic liver disease. Based on their clinical relevance, this review provides a summary of the most common post-translational modifications affecting HSA structural integrity and functions and their clinical relevance in the field of liver disease. The review also provides a critical description of the analytical approaches employed for the investigation of conformational alterations and the identification/quantitation of specific post-translational modifications affecting HSA. Finally, the analytical methods available for the assessment of two of the most clinically relevant non-oncotic properties of HSA, namely the binding capacity and the antioxidant activity, are critically reviewed. Among the available techniques particular attention is given to those proposed for the in vitro and in vivo investigation of structurally modified albumin.