Alastair O’Brien

Lipid mediators in immune dysfunction after severe inflammation

Highlights • Aberrant LM levels contribute to immune dysfunction in CI.• Aberrance reflects dysregulation of inflammatory resolution pathways or their failure.• Targeted manipulation of LMs restores immune competence and outcomes in animal models.• Stratified resolution-based immunomodulatory strategies hold therapeutic potential.

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).

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.

A Comparison of Human Neutrophils Acquired from Four Experimental Models of Inflammation

Defects in neutrophil function have been implicated in a wide spectrum of clinical conditions. Several models are employed to study activated human neutrophils akin to those found at a site of inflammation. These include whole blood (WB) ex vivo stimulation with lipopolysaccharide (LPS) and in vivo techniques: cantharidin blister, skin windows and intra-dermal injection of UV-killed E.coli (UVKEc). Neutrophils obtained from these have never been compared. We compared the activation status of neutrophils from each technique in order to inform the optimal model for use in human studies. Healthy male volunteers were randomised to undergo one of the four techniques (n = 5/group). LPS: WB stimulated with 1ng/ml of LPS for 4 hours. Cantharidin: 12.5μl of 0.1% cantharidin elicited a single blister, aspirated at 24 hours. Skin windows: four 6mm mechanical-suction blisters created, de-roofed and an exudate-collection chamber placed over the windows for 4 hours before aspiration. UVKEc: 1.5 x 107 UVKEc injected intra-dermally. A single 10mm mechanical-suction blister formed and aspirated at 4 hours. Unstimulated WB used as the control. Flow cytometry was used to determine activation status using CD16, CD11b, CD54, CD62L and CD88. Functional status was assessed with a phagocytosis assay. The pattern of neutrophil activation was similar in all models. Neutrophil CD11b was elevated in all models, most markedly in UVKEc (p<0.0001), and CD54 was also elevated but only significant in the LPS model (p = 0.001). CD62L was significantly reduced in all 4 models (p<0.0001) and CD88 was also suppressed in all. There were no changes in CD16 in any model, neither was there any significant difference in the phagocytic capacity of the neutrophils. In summary, there are no significant differences in activation marker expression or phagocytic capacity in the neutrophils obtained from each technique. Therefore we believe whole blood stimulation is the best model in experimentally challenging inpatient populations.

Prevalence and outcome of cirrhosis patients admitted to UK intensive care: a comparison against dialysis-dependent chronic renal failure patients: response to Berry and Thomson

Dear Editor, I thank Drs. Berry and Thompson for their comments and accept that the tone of the discussion in our article [1] was indeed negative. However, I feel that this was an accurate reflection of the data presented. I do share their concerns that the paper might be regarded as championing ‘‘therapeutic nihilism’’ in cirrhosis patients, in particular those with sepsis. This was not my intention. Rather, I feel that the onset of multi-organ failure (MOF) is such a catastrophic event in these patients that we should focus on the early phase of the illness, as indeed Drs. Berry and Thompson suggest. Whether this is in a highdependency environment or acute medical admissions unit will depend on the resources available. Regrettably, beyond supportive measures such as fluid resuscitation, nutrition, terlipressin and appropriate antibiotics, there is little to offer at present, but these measures have been demonstrated to improve outcome. I believe that hepatologists need to be more proactive and educate the acute admitting teams as these first 24 h are often crucial. The authors also make several other points I’d like to address: As I acknowledge in the paper, the comparison between renal failure and liver failure is most definitely imperfect. However, I feel that to suggest that renal failure often remains isolated from other organs is misleading given the well-established association with cardiovascular disease which remains the most common cause of death in the UK. That nutritional status is a key determinant of survival has been known for several decades, yet nutritional therapy is often overlooked and suboptimal in cirrhosis patients, and the authors are right to highlight this. However, the argument that we should disregard the severe mortality figures of MOF in cirrhosis simply because liver disease is increasing in the UK and affecting younger people is not logical and I cannot agree with this statement. The causes of this epidemic of liver disease are well documented and will require a multidisciplinary strategy involving hospital workers, addiction specialists, and those in public health, government and the food and drinks industry among others to tackle successfully. I wish to conclude on a note of optimism—as stated the survival figures are improving and increased clinical and laboratory research into this area will improve treatment yet further. However, it is difficult at present to envisage this happening in patients with established MOF, and I believe that we should focus our attention on patients at risk of organ failure as I feel the greatest gains will occur here.

Effectiveness of pneumococcal and influenza vaccines to prevent serious health complications in adults with chronic liver disease: a protocol for a systematic review

Introduction In advanced chronic liver disease, diseases caused by common bacteria Streptococcus pneumoniae or influenza virus put people at an increased risk of serious health complications and death. The effectiveness of the available vaccines in reducing the risk of poor health outcomes, however, is less clear. Methods and analysis We will search Medline (Ovid), Embase (Ovid), PubMed and Cochrane Central Register of Controlled Trials for published reports on randomised controlled trials and observational studies on the effectiveness of pneumococcal and influenza vaccines in people with chronic liver disease. Two independent reviewers will screen the studies for eligibility, extract data and assess study quality and risk of bias. Random effects meta-analyses will be performed as appropriate. Ethics and dissemination Formal ethical approval is not required, as no primary data will be collected for this study. We will publish results of this study in relevant peer-reviewed medical journal or journals. Where possible, the study results will also be presented as posters or talks at relevant medical conferences and meetings. PROSPERO registration number CRD42017067277.

P1327 : Attire: albumin to prevent infection in chronic liver failure

Background and Aims: Patients with cirrhosis are at a greatly increased risk of severe bacterial infection with survival directly related to extra-hepatic organ dysfunction. A defective innate immune response is considered to underlie this risk. There is however no medical strategy to restore immune competence in these patients. Elevated circulating Prostaglandin E2 (PGE2) levels contribute to immune suppression in acutely decompensated (AD) cirrhosis. PGE2 is more bioavailable because of decreased serum albumin levels in AD patients as albumin binds PGE2. The binding capacity of endogenous albumin is also known to be defective in cirrhosis. Human Albumin Solution (HAS), a safe and common intervention, could thus be repurposed as an immune restorative drug in AD patients. The primary aim of ATTIRE is to determine if raising serum albumin to >30 g/L in patients with decompensated cirrhosis will decrease rates of infection, extra hepatic organ dysfunction and death.

Prevalence and outcome of cirrhosis patients admitted to UK intensive care: a comparison against dialysis-dependent chronic renal failure patients: Reply to comments by Mason and Yeoman

Dear Editor, We thank Drs Mason and Yeoman for their comments on our paper [1] as these raise a number of very interesting points. However, we would challenge the statement that these points mitigate against our conclusions. As mentioned in the previous reply to Drs Berry and Thompson [2], we do not wish to be seen as champions of nihilism for patients with cirrhosis; rather, our pessimistic conclusions simply reflect the data presented. Indeed, despite improvements in many aspects of critical care over the last 20 years, ICU mortality rates associated with cirrhosis remain very high. We felt that it was time for a change in the message from ‘‘we must try harder’’ to something bolder. It is very hard to advocate continuing ICU care when mortality rates exceed 85–90 %, especially as the vast majority of patients will not be eligible for transplantation. We perhaps should have added a section about optimising pre-ICU care and feel the authors’ critical care bundle suggestion has considerable merit, although whether this would have a benefit on mortality rates remains of course uncertain. However, the suggestion that cirrhosis patients be admitted earlier to the ICU is simplistic and naive given that using Hospital Episode Statistic data we identified [100,000 patients admitted to UK hospitals 2010–2011 with complications of cirrhosis (http://www. hesonline.nhs.uk). As an alternative, we would suggest borrowing another approach from sepsis studies—that of early ‘‘goal-directed therapy’’ [3], either in the emergency room or on the acute admissions ward. Indeed, a recent study has demonstrated that delayed appropriate initial empiric antimicrobial therapy is associated with increased mortality in cirrhosis [4]. As we acknowledge in our paper, the comparison with renal replacement therapy is imperfect, and we again refer to this in our reply to Drs Berry and Thompson [2], However, this hardly mitigates against our conclusion that cirrhosis patients with organ failure have an extremely poor prognosis. Rather than labour this point, we would refer these authors to the very similar overall mortality (59.2 %) seen in patients with haematological malignancies admitted to ICU [5], as mentioned in our discussion; this is a group we hope that all will agree can be regarded as having a poor prognosis. We cannot agree that using the Intensive Care National Audit & Research Centre (ICNARC) database to examine the largest cohort of ICU admissions with liver cirrhosis reported to date can be regarded as a study weakness. We acknowledge in our discussion that neither the Acute Physiology and Chronic Health Evaluation II (APACHE II) nor ICNARC score contains information directly relating to liver failure and conclude that neither score can guide decision-making; however, the area under the receiver operating characteristic curve (AUROC) of 0.8 that is seen with the ICNARC score is comparable to that obtained using Sequential Organ Failure Assessment (SOFA) and Organ System Failure (OSF) models in other studies. Equally, the fact that these scores under-predicted mortality had not been reported before, and we thought it worthy of mention. Again, we do acknowledge in the paper that mortality associated with variceal bleeding has improved over time; as such, a breakdown of mortality associated with differing reasons for admission may have proved interesting. However, the key determinants of ICU mortality in patients with cirrhosis are sepsis and organ failure [6] and, therefore, the aim of the study was to examine these in detail.