ATTIRE: Albumin To prevenT Infection in chronic liveR failurE: study protocol for a single-arm feasibility trial

Prognostic Value of Serum Albumin Level in Critically Ill Patients: Observational Data From Large Intensive Care Unit Databases

Background

Decreased serum albumin level (SAL) is associated with adverse clinical outcomes. We designed the present study to further assess the prognostic value of SAL in critically ill patients based on data from large intensive care unit (ICU) databases.

Methods

This retrospective cohort study recruited 18,353 patients from the Medical Information Mart for Intensive Care IV (MIMIC-IV) database. Restricted cubic splines (RCS) were performed to visualize the association of SAL at admission with ICU and hospital mortalities. The prognostic value of SAL was analyzed using logistic regression models and receiver operating characteristic (ROC) curves in overall patients and subgroups.

Results

Restricted cubic splines revealed rapid increasing risks in ICU and hospital mortalities when SAL declined to below 30 g/l. Patients with SAL <30 g/l (n = 6,069) had higher ICU (13.7% vs. 6.4%, p < 0.001) and hospital (23.9% vs. 10.7%, p < 0.001) mortalities than those with SAL ≥30 g/l. Multivariable logistic regression model revealed that SAL <30 g/l independently correlated with higher risks of both ICU (odds ratio [OR]: 1.20, 95% confidence interval [CI]: 1.07–1.36) and hospital (OR: 1.51, 95% CI: 1.37–1.66) mortalities. However, the association diminished in patients with cirrhosis (OR: 1.16, 95% CI: 0.91–1.49 for ICU mortality; OR: 1.21, 95% CI: 1.00–1.48 for hospital mortality). ROC curves revealed a poor performance of SAL in predicting mortalities, both in overall patients and in those with cirrhosis.

Conclusions

Decreased SAL is associated with increased risk of mortality. However, it possesses low sensitivity and specificity for outcome prediction in critically ill patients, especially in those with cirrhosis.

Immune Regulatory Mediators in Plasma from Patients With Acute Decompensation Are Associated With 3-Month Mortality

BACKGROUND & AIMS

Infection is a common cause of death in patients with cirrhosis. We investigated the association between the innate immune response and death within 3 months of hospitalization.

METHODS

Plasma samples were collected on days 1, 5, 10, and 15 from participants recruited into the albumin to prevent infection in chronic liver failure feasibility study. Patients with acute decompensated cirrhosis were given albumin infusions at 10 hospitals in the United Kingdom. Data were obtained from 45 survivors and 27 non-survivors. We incubated monocyte-derived macrophages from healthy individuals with patients' plasma samples and measured activation following lipopolysaccharide administration, determined by secretion of tumor necrosis factor and soluble mediators of inflammation. Each analysis included samples from 4 to 14 patients.

RESULTS

Plasma samples from survivors vs non-survivors had different inflammatory profiles. Levels of prostaglandin E2 were high at times of patient hospitalization and decreased with albumin infusions. Increased levels of interleukin 4 (IL4) in plasma collected at day 5 of treatment were associated with survival at 3 months. Incubation of monocyte-derived macrophages with day 5 plasma from survivors, pre-incubated with a neutralizing antibody against IL4, caused a significant increase in tumor necrosis factor production to the level of non-survivor plasma. Although baseline characteristics were similar, non-survivors had higher white cell counts and levels of C-reactive protein and renal dysfunction.

CONCLUSIONS

We identified profiles of inflammatory markers in plasma that are associated with 3-month mortality in patients with acute decompensated cirrhosis given albumin. Increases in prostaglandin E2 might promote inflammation within the first few days after hospitalization, and increased levels of plasma IL4 at day 5 are associated with increased survival. Clinicaltrialsregister.eu: EudraCT 2014-002300-24.

Con: The Unclear Benefit of Albumin

Many studies have shown that 20% human albumin solution infusions improve circulatory function in patients with advanced liver disease, and this treatment is widely recommended and used by all hepatologists. However, it is more expensive than other crystalloids or colloids, and several countries suffer shortages of supply. This article examines whether other fluids might be considered for these patients.

ATTIRE: Albumin To prevenT Infection in chronic liveR failurE: study protocol for an interventional randomised controlled trial

INTRODUCTION

Circulating prostaglandin E₂ levels are elevated in acutely decompensated cirrhosis and have been shown to contribute to immune suppression. Albumin binds to and inactivates this immune-suppressive lipid mediator. Human albumin solution (HAS) could thus be repurposed as an immune-restorative drug in these patients.This is a phase III randomised controlled trial (RCT) to verify whether targeting a serum albumin level of ≥35 g/L in hospitalised patients with decompensated cirrhosis using repeated intravenous infusions of 20% HAS will reduce incidence of infection, renal dysfunction and mortality for the treatment period (maximum 14 days or discharge if <14 days) compared with standard medical care.

METHODS AND ANALYSIS

Albumin To prevenT Infection in chronic liveR failurE stage 2 is a multicentre, open-label, interventional RCT. Patients with decompensated cirrhosis admitted to the hospital with a serum albumin of <30 g/L are eligible, subject to exclusion criteria. Patients randomised to intravenous HAS will have this administered, according to serum albumin levels, for up to 14 days or discharge. The infusion protocol aims to increase serum albumin to near-normal levels.The composite primary endpoint is: new infection, renal dysfunction or mortality within the trial treatment period. Secondary endpoints include mortality at up to 6 months, incidence of other organ failures, cost-effectiveness and quality of life outcomes and time to liver transplant. The trial will recruit 866 patients at more than 30 sites across the UK.

ETHICSANDDISSEMINATION

Research ethics approval was given by the London-Brent research ethics committee (ref: 15/LO/0104). The clinical trials authorisation was issued by the medicines and healthcare products regulatory agency (ref: 20363/0350/001-0001). The trial is registered with the European Medicines Agency (EudraCT 2014-002300-24) and has been adopted by the National Institute for Health Research (ISRCTN 14174793). This manuscript refers to version 6.0 of the protocol. Results will be disseminated through peer-reviewed journals and international conferences. Recruitment of the first participant occurred on 25 January 2016.

Administration of Albumin Solution Increases Serum Levels of Albumin in Patients With Chronic Liver Failure in a Single-Arm Feasibility Trial

BACKGROUND & AIMS

Infections are life-threatening to patients with acute decompensation and acute-on-chronic liver failure (AD/ACLF). Patients with AD/ACLF have prostaglandin E2-mediated immune suppression, which can be reversed by administration of albumin; infusion of 20% human albumin solution (HAS) might improve outcomes of infections. We performed a feasibility study to determine optimal trial design, assess safety, and validate laboratory assessments of immune function to inform design of a phase 3 trial.

METHODS

We performed a prospective multicenter, single-arm, open-label trial of 79 patients with AD/ACLF and levels of albumin lower than 30 g/L, seen at 10 hospitals in the United Kingdom from May through December 2015. Patients were given daily infusions of 20% HAS, based on serum levels, for 14 days or until discharge from the hospital. Rates of infection, organ dysfunction, and in-hospital mortality were recorded. The primary end point was daily serum albumin level during the treatment period. Success would be demonstrated if 60% achieved and maintained serum albumin levels at or above 30 g/L on at least one third of days with recorded levels.

RESULTS

The patients' mean model for end-stage disease score was 20.9 ± 6.6. The primary end point (albumin ≥30 g/L on at least one third of days recorded) was achieved by 68 of the 79 patients; 75% of administrations were in accordance with suggested dosing regimen. Mean treatment duration was 10.3 days (104 ± 678 mL administered). There were 8 deaths and 13 serious adverse events, considered by the independent data-monitoring committee to be consistent with those expected. Twelve of 13 patients that developed either respiratory or cardiovascular dysfunction (based on ward-based clinical definitions) as their only organ dysfunction were alive at 30 days compared with 1 of 3 that developed renal dysfunction. Only 1 case of brain dysfunction was recorded.

CONCLUSIONS

In a feasibility trial, we found that administration of HAS increased serum levels of albumin in patients with AD/ACLF. The dosing regimen was acceptable at multiple sites and deemed safe by an independent data-monitoring committee. We also developed a robust system to record infections. The poor prognosis for patients with renal dysfunction was confirmed. However, patients with cardiovascular or respiratory dysfunction had good outcomes, which is counterintuitive. Severe encephalopathy appeared substantially under-reported, indicating that ward-based assessment of these parameters cannot be recorded with sufficient accuracy for use as a primary outcome in phase 3 trials. Trial registration no: EudraCT 2014-002300-24 and ISRCTN14174793.

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).