Ischaemia-modified albumin: a marker of bacterial infection in hospitalized patients with cirrhosis

Durability and on-treatment predictors of recompensation in entecavir-treated patients with hepatitis B and decompensated cirrhosis

Background & Aims

Hepatic recompensation may be achieved in patients with decompensated cirrhosis due to chronic hepatitis B (CHB) upon effective suppression of viral replication by nucleos(t)ide analogues (NAs). However, the optimal timing and predictors of recompensation and the subsequent clinical course of patients with CHB with vs. without recompensation are not well-defined.

Methods

This study was a retrospective extension of a multi-centre prospective cohort, focusing on patients with CHB and decompensated cirrhosis treated with entecavir. We followed patients beyond treatment week 120 until a second decompensation event or June 2023. We identified the optimal timing and predictors of recompensation by week 120, evaluated durability of recompensation in patients fulfilling recompensation criteria by week 120 and examined late recompensation in those who did not fulfil it by week 120.

Results

At treatment week 24, serum albumin ≥34 g/L predicted recompensation by week 120. The Brec-PAS model offered good predictive ability for recompensation by week 120. Of the 283 patients who finished 120 weeks of therapy, 175 were followed beyond week 120 (median follow-up: 240 weeks). Among the 106 patients achieving recompensation by week 120, 92 (86.8%) maintained recompensation for another 120 (72-168) weeks. Among the 69 patients without recompensation by week 120, 40.6% attained late recompensation during the subsequent 120 (72-168) weeks. Additionally, hepatocellular carcinoma incidence was lower in the recompensated group (5.0% vs. 16.13%, p = 0.002).

Conclusions

A serum albumin ≥34 g/L at treatment week 24 predicted recompensation by week 120. Recompensation achieved by week 120 of NA treatment is maintained in >80% of patients in the long term. Some patients may achieve recompensation only after >120 weeks of NA treatment. The incidence of hepatocellular carcinoma was reduced but not completely abolished after recompensation.

Impact and implications

Our research provides a meaningful contribution to understanding the long-term prognosis of recompensation in patients with chronic hepatitis B and decompensated cirrhosis, as well as to evaluating the predictive value of serum albumin levels, offering a comprehensive view of clinical outcomes after recompensation. The significance of early biomarkers in guiding therapeutic decisions is highlighted, shedding light on the continued benefits and possible risks after recompensation. This enhances the capability for more precise prognostic evaluations and informed therapeutic strategies. For healthcare providers, these insights afford a detailed perspective on patient monitoring and intervention planning, underscoring the need for ongoing assessment past the initial recompensation phase.

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.

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.

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.

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.

Current Status and Prospects of Spontaneous Peritonitis in Patients with Cirrhosis

Spontaneous bacterial peritonitis (SBP) is a common cirrhotic ascites complication which exacerbates the patient's condition. SBP is caused by gram-negative bacilli and, to a lesser extent, gram-positive cocci. Hospital-acquired infections show higher levels of drug-resistant bacteria. Geographical location influences pathogenic bacteria distribution; therefore, different hospitals in the same country record different bacteria strains. Intestinal changes and a weak immune system in patients with liver cirrhosis lead to bacterial translocation thus causing SBP. Early diagnosis and timely treatment are important in SBP management. When the treatment effect is not effective, other rare pathogens should be explored.

Causes and Consequences of Innate Immune Dysfunction in Cirrhosis

Liver cirrhosis is an increasing health burden and public health concern. Regardless of etiology, patients with cirrhosis are at risk of a range of life-threatening complications, including the development of infections, which are associated with high morbidity and mortality and frequent hospital admissions. The term Cirrhosis-Associated Immune Dysfunction (CAID) refers to a dynamic spectrum of immunological perturbations that develop in patients with cirrhosis, which are intimately linked to the underlying liver disease, and negatively correlated with prognosis. At the two extremes of the CAID spectrum are systemic inflammation, which can exacerbate clinical manifestations of cirrhosis such as hemodynamic derangement and kidney injury; and immunodeficiency, which contributes to the high rate of infection in patients with decompensated cirrhosis. Innate immune cells, in particular monocytes/macrophages and neutrophils, are pivotal effector and target cells in CAID. This review focuses on the pathophysiological mechanisms leading to impaired innate immune function in cirrhosis. Knowledge of the phenotypic manifestation and pathophysiological mechanisms of cirrhosis associated immunosuppression may lead to immune targeted therapies to reduce susceptibility to infection in patients with cirrhosis, and better biomarkers for risk stratification, and assessment of efficacy of novel immunotherapies.

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.

Albumin Counteracts Immune-Suppressive Effects of Lipid Mediators in Patients With Advanced Liver Disease

BACKGROUND & AIMS

Patients with acute decompensation and acute-on-chronic liver failure (AD/ACLF) have immune dysfunction, which increases their risk for infections; however, there are no effective treatments to restore their immune function. We investigated whether the potentially immune-restorative effects of albumin are mediated by its effects on prostaglandin E₂ (PGE₂) and other lipids.

METHODS

We analyzed bloods samples from 45 of 79 patients with AD/ACLF and serum levels of albumin less than 30 g/L for whom infusion of 20% human albumin solution (HAS) increased serum levels of albumin 30 g/L or more in a feasibility study of effects of 20% HAS. Immune function was determined by comparison of macrophage function following addition of plasma samples. We also used samples from 12 healthy individuals. We measured binding of plasma proteins to PGE₂ and serum levels of endotoxin (lipopolysaccharide) and cytokines; using 10 patients' samples, we investigated the effects of PGE₂ inhibitors. We performed a comprehensive lipid metabolomic analysis using samples from 10 different patients, before and after HAS administration.

RESULTS

At baseline, AD/ACLF patient plasma induced significantly lower production of tumor necrosis factor by healthy macrophages than plasma from healthy individuals (P < .0001). Plasma from patients after HAS infusion induced significantly higher levels of tumor necrosis factor production by macrophages (19.5 ± 4.8 ng/mL) compared with plasma collected before treatment (17.7 ± 4.5 ng/mL; P = .0013). There was a significantly lower proportion of plasma protein (albumin) binding to PGE₂ from patients with AD/ACLF plasma (mean, 61.9%) compared with plasma from control subjects (77.1%; P = .0012). AD/ACLF plasma protein binding to PGE₂ increased following HAS treatment compared with baseline (mean increase, 8.7%; P < .0001). Circulating levels of PGE₂, lipopolysaccharide, and inflammatory or anti-inflammatory cytokines were higher in patients with AD/ACLF than healthy volunteers. Unexpectedly, HAS infusion had no effect on mediator levels. Principal component analysis of baseline levels of lipids that induce or resolve inflammation identified 2 distinct groups of patients that differed according to baseline plasma level of lipopolysaccharide. Sample analyses after HAS treatment indicated that albumin regulates circulating levels of lipid mediators, but this effect was distinct in each group.

CONCLUSIONS

Analysis of blood samples from patients with AD/ACLF participating in a feasibility study of 20% HAS infusions has shown that infusions to raise serum albumin above 30 g/L reversed plasma-mediated immune dysfunction by binding and inactivating PGE₂. We also describe a method to classify the inflammatory response in AD/ACLF, based on lipid profile, which could improve identification of patients most likely to respond to HAS treatment. A randomized controlled trial is needed to determine whether these effects of HAS reduce infections in AD/ACLF. Trial registered with European Medicines Agency (EudraCT 2014-002300-24) and adopted by NIHR (ISRCTN14174793).

Is ischemia-modified albumin a reliable tool for the assessment of acute pancreatitis?

PURPOSE

Oxidative stress has been implicated in several disorders, including acute pancreatitis (AP). Ischemia-modified albumin (IMA), which reflects the ability to bind cobalt, has been found to be elevated in conditions of oxidative stress and tissue hypoxia. This study examined IMA and adjusted IMA levels in patients with AP, and examined the associations of IMA and adjusted IMA levels to the severity of AP.

PATIENTS AND METHODS

A total of 42 consecutive patients with AP and 43 age- and sex-matched control subjects were enrolled. Serum samples were obtained from patients with AP on admission as well as 48-72 hours after hospitalization, and from the controls, at the time of enrollment. Adjusted IMA was calculated by multiplying the IMA value of each patient with the ratio of the patient's albumin value and the median albumin value of the study population. The severity of AP was assessed according to the modified Atlanta classification, and the patients were divided into 2 groups: mild AP and severe AP.

RESULTS

The serum IMA and adjusted IMA values of patients with AP on admission and those of the controls did not differ (p=0.86 and p=0.99, respectively). The second measurements of IMA and adjusted IMA in the AP group were higher than the first measurements of both the AP group and controls (for all, p<0.01). Among the IMA measurements, only adjusted IMA on admission had the ability to predict the severity of AP. Severe AP was correlated with albumin, and the area under the curve of adjusted IMA values on admission was 0.746 for differentiating patients with severe AP from mild AP with statistical significance (p=0.005).

CONCLUSION

It was shown that IMA and adjusted IMA levels rise with the progression of AP. Lower levels of adjusted IMA predict the severity of AP. Further studies with serial measurements of IMA are warranted to explore the indicative role of IMA in the course of AP.

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.

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

Decompensated cirrhosis is associated to extensive post-transcriptional changes of human albumin (HA). This study aims to characterize the occurrence of HA homodimerization in a large cohort of patients with decompensated cirrhosis and to evaluate its association with clinical features and prognosis. HA monomeric and dimeric isoforms were identified in peripheral blood by using a HPLC-ESI-MS technique in 123 cirrhotic patients hospitalized for acute decompensation and 50 age- and sex-comparable healthy controls. Clinical and biochemical parameters were recorded and patients followed up to one year. Among the monomeric isoforms identified, the N- and C-terminal truncated and the native HA underwent homodimerization. All three homodimers were significantly more abundant in patients with cirrhosis, acute-on-chronic liver failure and correlate with the prognostic scores. The homodimeric N-terminal truncated isoform was independently associated to disease complications and was able to stratify 1-year survival. As a result of all these changes, the monomeric native HA was significantly decreased in patients with cirrhosis, being also associated with a poorer prognosis. In conclusion homodimerization is a novel described structural alteration of the HA molecule in decompensated cirrhosis and contributes to the progressive reduction of the monomeric native HA, the only isoform provided of structural and functional integrity.

Mass spectrometry characterization of circulating human serum albumin microheterogeneity in patients with alcoholic hepatitis

Human serum albumin (HSA) is the most abundant plasma protein, endowed with several biological properties unrelated to its oncotic power, such as antioxidant and free-radicals scavenging activities, binding and transport of many endogenous and exogenous substances, and regulation of endothelial function and inflammatory response. These non-oncotic activities are closely connected to the peculiarly dynamic structure of the albumin molecule. HSA undergoes spontaneous structural modifications, mainly by reaction with oxidants and saccharides; however, patients with cirrhosis show extensive post-transcriptional changes at several molecular sites of HSA, the degree of which parallels the severity of the disease. The present work reports the development and application of an innovative LC-MS analytical method for a rapid and reproducible determination of the relative abundance of HSA isoforms in plasma samples from alcoholic hepatitis (AH) patients. A condition of severe oxidative stress, similar to that observed in AH patients, is associated with profound changes in circulating HSA microheterogeneity. More interestingly, the high resolution provided by the analytical platform allowed the monitoring of novel oxidative products of HSA never reported before.

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.