Low serum concentration of apolipoprotein A-I is an indicator of poor prognosis in cirrhotic patients with severe sepsis

Computational Design and In Vitro and In Vivo Characterization of an ApoE-Based Synthetic High-Density Lipoprotein for Sepsis Therapy

Introduction: Septic patients have low levels of high-density lipoproteins (HDLs), which is a risk factor. Replenishing HDLs with synthetic HDLs (sHDLs) has shown promise as a therapy for sepsis. This study aimed to develop a computational approach to design and test new types of sHDLs for sepsis treatment. Methods: We used a three-step computational approach to design sHDL nanoparticles based on the structure of HDLs and their binding to endotoxins. We tested the efficacy of these sHDLs in two sepsis mouse models-cecal ligation and puncture (CLP)-induced and P. aeruginosa-induced sepsis models-and assessed their impact on inflammatory signaling in cells. Results: We designed four sHDL nanoparticles: two based on the ApoA-I sequence (YGZL1 and YGZL2) and two based on the ApoE sequence (YGZL3 and YGZL4). We demonstrated that an ApoE-based sHDL nanoparticle, YGZL3, provides effective protection against CLP- and P. aeruginosa-induced sepsis. The sHDLs effectively suppressed inflammatory signaling in HEK-blue or RAW264 cells. Conclusions: Unlike earlier approaches, we developed a new approach that employs computational simulations to design a new type of sHDL based on HDL's structure and function. We found that YGZL3, an ApoE sequence-based sHDL, provides effective protection against sepsis in two mouse models.

A new prognostic model based on serum apolipoprotein AI in patients with HBV-ACLF and acutely decompensated liver cirrhosis

BACKGROUND/AIM

To investigate the prognostic value of circulating apolipoprotein AI (apoAI) levels and develop a new prognostic model in individuals with acute-on-chronic liver failure (ACLF) and acute decompensation (AD) of liver cirrhosis caused by hepatitis B virus (HBV) infection.

METHODS

Baseline levels of serum lipids were measured, and data concerning the presence of complications were collected from 561 HBV-ACLF and AD patients. Survival analysis was conducted by log-rank test. Proportional hazards model was used to perform multivariate analysis. The dynamics of serum apoAI levels were also explored in 37 HBV-ACLF patients.

RESULTS

In the cohort, the negatively correlation was found between the Model for End-Stage Liver Disease (MELD) score and serum apoAI levels (r = -0.7946, P < 0.001). Circulating apoAI concentration was an independent risk factor for 90-day survival according to Cox multivariate analysis. A new prognostic score-integrated serum lipid profile for ACLF patients (Lip-ACLF score = 0.86×International Normalized Ratio (INR) + 0.0034×total bilirubin (TBIL) (µmol/L) + 0.99× hepatorenal syndrome (HRS) (HRS: no/1; with/2) + 0.50×hepatic encephalopathy (HE) (grade/ponint: no/1; 1-2/2; 3-4/3) - 2.97×apoAI (g/L) + 5.2) was subsequently designed for the derivation cohort. Compared to MELD score, Child-Turcotte-Pugh (CTP) score or apoAI, Lip-ACLFs was superior for the prediction of 90-day outcomes (receiver operating characteristic curve (ROC): 0.930 vs. 0.885, 0.833 or 0.856, all P < 0.01), as was the validation cohort (ROC 0.906 vs. 0.839, 0.857 or 0.837, all P < 0.05). In Kaplan‒Meier survival analysis, low apoAI levels (< 0.42 g/L) at baseline indicated poor prognosis in ACLF and AD patients. Among the 37 patients, the deceased individuals were characterised with significantly decreased serum apoAI levels during the follow-up test compared with those at baseline (P < 0.05), whereas in patients with a good prognosis, the serum apoAI levels remained stable during the follow-up.

CONCLUSION

In HBV-ACLF and AD patients, lower serum apoAI levels suggest greater disease severity and 90-day mortality risk. For predicting the short-term prognosis of these patients, the new Lip-ACLF score might serve as a potential model.

Top-Down Proteomics Identifies Plasma Proteoform Signatures of Liver Cirrhosis Progression

Cirrhosis, advanced liver disease, affects 2 to 5 million Americans. While most patients have compensated cirrhosis and may be fairly asymptomatic, many decompensate and experience life-threatening complications such as gastrointestinal bleeding, confusion (hepatic encephalopathy), and ascites, reducing life expectancy from 12 to less than 2 years. Among patients with compensated cirrhosis, identifying patients at high risk of decompensation is critical to optimize care and reduce morbidity and mortality. Therefore, it is important to preferentially direct them towards specialty care which cannot be provided to all patients with cirrhosis. We used discovery top-down proteomics to identify differentially expressed proteoforms (DEPs) in the plasma of patients with progressive stages of liver cirrhosis with the ultimate goal to identify candidate biomarkers of disease progression. In this pilot study, we identified 209 DEPs across three stages of cirrhosis (compensated, compensated with portal hypertension, and decompensated), of which 115 derived from proteins enriched in the liver at a transcriptional level and discriminated the three stages of cirrhosis. Enrichment analyses demonstrated DEPs are involved in several metabolic and immunological processes known to be impacted by cirrhosis progression. We have preliminarily defined the plasma proteoform signatures of cirrhosis patients, setting the stage for ongoing discovery and validation of biomarkers for early diagnosis, risk stratification, and disease monitoring.

Elevated free cholesterol levels due to impaired reverse cholesterol transport are a risk factor for polymicrobial sepsis in mice

Dysregulated lipid metabolism is commonly observed in septic patients, but how it contributes to sepsis remains largely unknown. Reverse cholesterol transport (RCT) is crucial for regulating cholesterol metabolism in circulation. During RCT, high-density lipoprotein collects cholesterol from peripheral tissues and transports it to the liver's scavenger receptor BI (SR-BI), where SR-BI mediates the uptake of cholesteryl esters (CEs) from high-density lipoprotein for excretion via bile. In this study, we utilized AlbCreSR-BIfl/fl mice, a model with impaired RCT, to investigate the impact of RCT on sepsis. We found that AlbCreSR-BIfl/fl mice were significantly more susceptible to cecal ligation and puncture (CLP)-induced polymicrobial sepsis, with a survival rate of 14.3% compared to 80% in SR-BIfl/fl littermates. Mechanistically, sepsis disrupted cholesterol metabolism, causing a 4.8-fold increase in free cholesterol (FC) levels and a 4-fold increase in the FC/CE ratio in AlbCreSR-BIfl/fl mice compared to SR-BIfl/fl littermates. This disruption led to hemolysis and death. Notably, administering the cholesterol-lowering drug probucol normalized FC levels and the FC/CE ratio, and significantly improved survival in CLP-AlbCreSR-BIfl/fl mice. However, probucol treatment reduced survival in CLP-low-density lipoprotein receptor knockout mice, which had elevated CE levels with a low FC/CE ratio. These results highlight that elevated FC levels with high FC/CE ratio are a risk factor for sepsis. Therefore, selectively targeting elevated FC levels and FC/CE ratio could be a promising therapeutic strategy for managing sepsis.

Utilize proteomic analysis to identify potential therapeutic targets for combating sepsis and sepsis-related death

Background

Sepsis is an inflammatory disease that leads to severe mortality, highlighting the urgent need to identify new therapeutic strategies for sepsis. Proteomic research serves as a primary source for drug target identification. We employed proteome-wide Mendelian randomization (MR), genetic correlation analysis, and colocalization analysis to identify potential targets for sepsis and sepsis-related death.

Methods

Genetic data for plasma proteomics were obtained from 35,559 Icelandic individuals and an initial MR analysis was conducted using 13,531 sepsis cases from the FinnGen R10 cohort to identify associations between plasma proteins and sepsis. Subsequently, significant proteins underwent genetic correlation analysis, followed by replication in 54,306 participants from the UK Biobank Pharma Proteomics Project and validation in 11,643 sepsis cases from the UK Biobank. The identified proteins were then subjected to colocalization analysis, enrichment analysis, and protein-protein interaction network analysis. Additionally, we also investigated a MR analysis using plasma proteins on 1,896 sepsis cases with 28-day mortality from the UK Biobank.

Results

After FDR correction, MR analysis results showed a significant causal relationship between 113 plasma proteins and sepsis. Genetic correlation analysis revealed that only 8 proteins had genetic correlations with sepsis. In the UKB-PPP replication analysis, only 4 proteins were found to be closely associated with sepsis, while validation in the UK Biobank sepsis cases found overlaps for 21 proteins. In total, 30 proteins were identified in the aforementioned analyses, and colocalization analysis revealed that only 2 of these proteins were closely associated with sepsis. Additionally, in the 28-day mortality MR analysis of sepsis, we also found that only 2 proteins were significant.

Conclusions

The identified plasma proteins and their associated metabolic pathways have enhanced our understanding of the complex relationship between proteins and sepsis. This provides new avenues for the development of drug targets and paves the way for further research in this field.

Top-Down Proteomics Identifies Plasma Proteoform Signatures of Liver Cirrhosis Progression

Cirrhosis, advanced liver disease, affects 2-5 million Americans. While most patients have compensated cirrhosis and may be fairly asymptomatic, many decompensate and experience life-threatening complications such as gastrointestinal bleeding, confusion (hepatic encephalopathy), and ascites, reducing life expectancy from 12 to less than 2 years. Among patients with compensated cirrhosis, identifying patients at high risk of decompensation is critical to optimize care and reduce morbidity and mortality. Therefore, it is important to preferentially direct them towards specialty care which cannot be provided to all patients with cirrhosis. We used discovery Top-down Proteomics (TDP) to identify differentially expressed proteoforms (DEPs) in the plasma of patients with progressive stages of liver cirrhosis with the ultimate goal to identify candidate biomarkers of disease progression. In this pilot study, we identified 209 DEPs across three stages of cirrhosis (compensated, compensated with portal hypertension, and decompensated), of which 115 derived from proteins enriched in the liver at a transcriptional level and discriminated the three stages of cirrhosis. Enrichment analyses demonstrated DEPs are involved in several metabolic and immunological processes known to be impacted by cirrhosis progression. We have preliminarily defined the plasma proteoform signatures of cirrhosis patients, setting the stage for ongoing discovery and validation of biomarkers for early diagnosis, risk stratification, and disease monitoring.

Phospholipids impact the protective effects of HDL-mimetic nanodiscs against lipopolysaccharide-induced inflammation

Aim: The impacts of synthetic high-density lipoprotein (sHDL) phospholipid components on anti-sepsis effects were investigated. Methods: sHDL composed with ApoA-I mimetic peptide (22A) and different phosphatidylcholines were prepared and characterized. Anti-inflammatory effects were investigated in vitro and in vivo on lipopolysaccharide (LPS)-induced inflammation models. Results: sHDLs composed with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (22A-DMPC) most effectively neutralizes LPS, inhibits toll-like receptor 4 recruitment into lipid rafts, suppresses nuclear factor κB signaling and promotes activating transcription factor 3 activating. The lethal endotoxemia animal model showed the protective effects of 22A-DMPC. Conclusion: Phospholipid components affect the stability and fluidity of nanodiscs, impacting the anti-septic efficacy of sHDLs. 22A-DMPC presents the strongest LPS binding and anti-inflammatory effects in vitro and in vivo, suggesting a potential sepsis treatment.

Apolipoprotein M bound sphingosine 1-phosphate suppresses NETosis through activating S1P1 and S1P4

The pleiotropic effects of high-density lipoprotein (HDL), including its protective properties against sepsis, are attributed to the sphingosine 1-phosphate and apolipoprotein M (ApoM) that are carried on the lipoproteins. In this study, we attempted to elucidate the possible mechanisms underlying the sepsis coagulopathic state by considering the modulation of NETosis. Our results revealed that in a lipopolysaccharide-induced sepsis mouse model, the levels of NETosis markers, such as plasma DNA and histone, were elevated in ApoM-knockout (KO) mice and attenuated in ApoM-overexpressing mice. In ApoM-KO mice, the survival rate decreased and the occurrence rates of coagulopathy and organ injury increased following the administration of histone. Treatment with a conditioned medium of ApoM-overexpressing cells attenuated the observed NETosis in HL-60S cells that differentiated into neutrophils and were inhibited through the suppression of S1P1 or S1P4. The attenuation of PKCδ and PKCα/β by S1P1 and S1P4 activation may also be involved. In ApoM-overexpressing mice, coagulopathy and organ injuries were attenuated following an injection of histone; these effects were partially inhibited by S1P1, 3, S1P4, or S1P1 antagonists. Furthermore, the exogenous administration of ApoM protected ApoM-KO mice that were challenged with histone from developing NETosis. In conclusion, the ApoM/S1P axis protects against NETosis through the attenuation of PKC activation by S1P1 and S1P4. The development of drugs targeting the ApoM/S1P axis may be beneficial for the treatment of pathological conditions involving uncontrolled NETosis, such as sepsis.

Predictive value of serum apolipoprotein A-I in the organ failure of acute pancreatitis: a retrospective cohort study

BACKGROUND

Organ failure (OF) largely governs the outcomes and mortality in patients with acute pancreatitis (AP), but there is a lack of optimal prognostic biomarker for OF. This study is designed to investigate whether the serum apolipoprotein A-I (Apo A-I) level can predict OF in patients with AP.

METHODS

A total of 424 patients with AP were reviewed in the study, and we finally got 228 patients eligible for analysis. Patients were divided into two groups based on serum Apo A-I level. Demographic information and clinical materials were retrospectively collected. The primary outcome was the occurrence of OF. Univariate and multivariate binary logistic regression were conducted to analyze the relationship between Apo A-I and OF. Additionally, we used receiver operating characteristic analysis to clarify the predictive value of serum Apo A-I level for OF and mortality.

RESULTS

Ninety-two patients and 136 patients were included in Apo A-I low and non-low groups, respectively. The occurrence of OF was significantly different in the two groups (35.9 vs. 9.6%, p < 0.001). Moreover, serum Apo A-I level markedly decreased across disease severity based on the 2012 Revised Atlanta Classification of AP. The decrease of serum apolipoprotein A-I was an independent risk factor for organ failure (OR: 6.216, 95% CI: 2.610, 14.806, p < 0.001). The area under the curve of serum Apo A-I was 0.828 and 0.889 for OF and mortality of AP, respectively.

CONCLUSIONS

Serum Apo A-I level in the early stage of the disease has a high predictive value for OF of AP.

Association Between Hypocholesterolemia and Mortality in Critically Ill Patients With Sepsis: A Systematic Review and Meta-Analysis

To ascertain the association between cholesterol and triglyceride levels on ICU admission and mortality in patients with sepsis.

DATA SOURCES

Systematic review and meta-analysis of published studies on PubMed and Embase.

STUDY SELECTION

All observational studies reporting ICU admission cholesterol and triglyceride levels in critically ill patients with sepsis were included. Authors were contacted for further data.

DATA EXTRACTION

Eighteen observational studies were identified, including 1,283 patients with a crude overall mortality of 33.3%. Data were assessed using Revman (Version 5.1, Cochrane Collaboration, Oxford, United Kingdom) and presented as mean difference (MD) with 95% CIs, p values, and I 2 values.

DATA SYNTHESIS

Admission levels of total cholesterol (17 studies, 1,204 patients; MD = 0.52 mmol/L [0.27-0.77 mmol/L]; p < 0.001; I 2 = 91%), high-density lipoprotein (HDL)-cholesterol (14 studies, 991 patients; MD = 0.08 mmol/L [0.01-0.15 mmol/L]; p = 0.02; I 2 = 61%), and low-density lipoprotein (LDL)-cholesterol (15 studies, 1,017 patients; MD = 0.18 mmol/L [0.04-0.32 mmol/L]; p = 0.01; I 2 = 71%) were significantly lower in eventual nonsurvivors compared with survivors. No association was seen between admission triglyceride levels and mortality (15 studies, 1,070 patients; MD = 0.00 mmol/L [-0.16 to 0.15 mmol/L]; p = -0.95; I 2 = 79%).

CONCLUSIONS

Mortality was associated with lower levels of total cholesterol, HDL-cholesterol, and LDL-cholesterol, but not triglyceride levels, in patients admitted to ICU with sepsis. The impact of cholesterol replacement on patient outcomes in sepsis, particularly in at-risk groups, merits investigation.

Biomarkers of hepatocellular synthesis in patients with decompensated cirrhosis

BACKGROUND AND AIM

Since hepatocytes produce majority of serum proteins, patients with cirrhosis display substantial alterations in the serum proteome. The aim of the current study was to characterize these changes and to study the prognostic utility of hepatocellular proteins available in routine clinical testing.

METHODS

Sera from 29 healthy controls and 43 patients with cirrhosis were subjected to untargeted proteomic analysis. Unsupervised hierarchical clustering was performed with Perseus software and R. Ingenuity pathway analysis (IPA) suggested upstream regulators that were validated in liver tissues. The behavior and prognostic usefulness of selected biomarkers was investigated in 61 controls and 285 subjects with decompensated cirrhosis.

RESULTS

Proteomics uncovered 65 and 16 hepatocellular serum proteins that are significantly downregulated or upregulated in patients with cirrhosis vs. controls. Hierarchical clustering revealed two main clusters and six sub-clusters. IPA identified HNF4α and IL-6 as the two major upstream regulators that were confirmed by hepatic gene expression analyses. Among pseudocholinesterase, transferrin, transthyretin, albumin, and apolipoprotein AI (Apo-AI), Apo-AI was the best predictor of 90-days transplant-free survival (AUROC 0.678; p = 0.0001) and remained an independent predictor in multivariable Cox independently of the presence of acute-on-chronic liver failure.

CONCLUSION

Our study reveals cirrhosis-associated changes in hepatocellular serum proteins and underlying transcription factors. Serum apolipoprotein AI may constitute a useful prognostic adjunct in patients with decompensated cirrhosis.

Replenishing HDL with synthetic HDL has multiple protective effects against sepsis in mice

Sepsis is a major health issue with mortality exceeding 30% and few treatment options. We found that high-density lipoprotein cholesterol (HDL-C) abundance was reduced by 45% in septic patients compared to that in nonseptic patients. Furthermore, HDL-C abundance in nonsurviving septic patients was substantially lower than in those patients who survived. We therefore hypothesized that replenishing HDL might be a therapeutic approach for treating sepsis and found that supplementing HDL with synthetic HDL (sHDL) provided protection against sepsis in mice. In mice subjected to cecal ligation and puncture (CLP), infusing the sHDL ETC-642 increased plasma HDL-C amounts and improved the 7-day survival rate. Septic mice treated with sHDL showed improved kidney function and reduced inflammation, as indicated by marked decreases in the plasma concentrations of blood urea nitrogen (BUN) and the cytokines interleukin-6 (IL-6) and IL-10, respectively. We found that sHDL inhibited the ability of the endotoxins LPS and LPA to activate inflammatory pathways in RAW264.7 cells and HEK-Blue cells expressing the receptors TLR4 or TLR2 and NF-κB reporters. In addition, sHDL inhibited the activation of HUVECs by LPS, LTA, and TNF-α. Together, these data indicate that sHDL treatment protects mice from sepsis in multiple ways and that it might be an effective therapy for patients with sepsis.

Association between high-density lipoprotein cholesterol and apolipoprotein A-I and severe acute pancreatitis: a case-control study

BACKGROUND

Evidence is limited concerning the association between serum concentrations of high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (APO A-I) and severe acute pancreatitis (SAP). This study was designed to explore whether HDL-C and APO A-I were independently correlated to SAP after adjusting for covariates.

METHODS

There were 1127 patients with acute pancreatitis who were recruited from a tertiary teaching hospital in Wenzhou from 1 January 2018 to 30 April 2020. The independent variables were baseline levels of HDL-C, and APO A-I collected within 24 h after admission. The dependent variable was the occurrence of SAP during hospitalization. Univariate and multivariate binary logistic regression were conducted to analyze the relationship between HDL-C and APO A-I and SAP. The receiver operating characteristic curve was applied to analyze the prediction power of lipid parameters and C-reactive protein for SAP.

RESULTS

The incidence of SAP was 11.5% among the 678 patients included in the final analysis. The serum levels of APO A-I and HDL-C were negatively related to SAP after adjusting for confounders with an odds ratio of 0.24 [95% confidence interval (CI): 0.06-0.95] and 0.16 (95% CI, 0.04-0.56), respectively. APO A-I (area under the curve = 0.69; 95% CI, 0.63-0.76) and HDL-C (area under the curve = 0.72; 95% CI, 0.66-0.79) showed higher predictive value for SAP compared with other lipid parameters.

CONCLUSIONS

Decreased serum concentrations of HDL-C and APO A-I are associated with SAP after adjusting for covariates.

Association of lipid profile with decompensation, liver dysfunction, and mortality in patients with liver cirrhosis

BACKGROUND AND AIMS

Lipid metabolism is often disrupted in liver cirrhosis. The present study aimed to evaluate the impact of lipid profile on decompensation events, severity of liver dysfunction, and death in patients with liver cirrhosis.

METHODS

In a cross-sectional study, 778 patients with lipid profile data were enrolled, and then were divided into 240 and 538 patients with and without liver cirrhosis, respectively. In a cohort study, 314 cirrhotic patients with lipid profile data, who were prospectively followed, were enrolled. Lipid profile included total cholesterol (TC), high-density lipoprotein-cholesterol (HDL-c), low-density lipoprotein-cholesterol (LDL-c), triglycerides (TG), and lipoprotein(a).

RESULTS

In the cross-sectional study, cirrhotic patients with decompensation events had significantly lower levels of TC and lipoprotein(a) than those without; and cirrhotic patients with Child-Pugh class B and C had significantly lower levels of TC, HDL-c, LDL-c, and lipoprotein(a) than those with Child-Pugh class A. In the cohort study, there was an inverse association of survival with TC, HDL-c, and lipoprotein(a) levels; after adjusting for MELD score, TC (Hazard Ratio [HR] = 1.703, P = 0.034) and HDL-c (HR = 2.036, P = 0.005), but not lipoprotein(a) (HR = 1.377, P = 0.191), remained a significant predictor of death; when TC, HDL-c, lipoprotein(a), and MELD score were included in the multivariate Cox regression analysis, HDL-c (HR = 1.844, P = 0.024) was the only independent predictor of death.

CONCLUSIONS

Decreased levels in specific components of lipid profile indicate more decompensation events, worse liver function, and reduced survival in liver cirrhosis. MELD score combined with HDL-c should be promising for the assessment of outcomes of cirrhotic patients.

Multifaced Roles of HDL in Sepsis and SARS-CoV-2 Infection: Renal Implications

High-density lipoproteins (HDLs) are a class of blood particles, principally involved in mediating reverse cholesterol transport from peripheral tissue to liver. Omics approaches have identified crucial mediators in the HDL proteomic and lipidomic profile, which are involved in distinct pleiotropic functions. Besides their role as cholesterol transporter, HDLs display anti-inflammatory, anti-apoptotic, anti-thrombotic, and anti-infection properties. Experimental and clinical studies have unveiled significant changes in both HDL serum amount and composition that lead to dysregulated host immune response and endothelial dysfunction in the course of sepsis. Most SARS-Coronavirus-2-infected patients admitted to the intensive care unit showed common features of sepsis disease, such as the overwhelmed systemic inflammatory response and the alterations in serum lipid profile. Despite relevant advances, episodes of mild to moderate acute kidney injury (AKI), occurring during systemic inflammatory diseases, are associated with long-term complications, and high risk of mortality. The multi-faceted relationship of kidney dysfunction with dyslipidemia and inflammation encourages to deepen the clarification of the mechanisms connecting these elements. This review analyzes the multifaced roles of HDL in inflammatory diseases, the renal involvement in lipid metabolism, and the novel potential HDL-based therapies.

High-Density Lipoproteins and Acute Kidney Injury

High-density lipoprotein (HDL) particles, best known for their anti-atherosclerotic effects, also may play a beneficial role during acute renal stress. HDL from healthy human beings also shows anti-inflammatory and anti-oxidant capacities, promotes endothelial function and repair, and serves as a systemic signaling mechanism facilitating rapid interorgan communication during times of physiologic stress. Higher concentrations of HDL are associated with less acute kidney injury after sepsis, cardiac and vascular surgery, and contrast-exposure during percutaneous coronary interventions. A better understanding of the interplay between HDL and the kidney both under homeostatic conditions and under acute physiologic stress could lead to the identification of novel risk factors and therapeutic targets for acute kidney injury prevention and treatment in the future.

Lipid metabolism changes in patients with severe COVID-19

Background

We investigated the dynamic changes in lipid profiles and their correlations with disease severity and clinical outcome in patients with severe COVID-19.

Methods

We retrospectively reviewed 519 severe COVID-19 patients with confirmed outcomes (discharged or deceased), admitted to the West Court of Union Hospital in Wuhan, China, between 29 January and 8 April 2020.

Results

Altogether, 424 severe COVID-19 patients, including 34 non-survivors and 390 survivors, were included in the final analyses. During hospitalization, low-density lipoprotein cholesterol (LDL-C), total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C) and apolipoprotein A-I (apoA-I) showed an increasing trend in survivors, but showed a downward trend in non-survivors. The serum concentrations of HDL-C and apoA-I were inversely correlated with C-reactive protein (CRP), length of hospital stay of survivors, and disease severity scores. For in-hospital deaths, the areas under the receiver operating characteristic curves (AUCs) of the ratios of CRP/HDL-C and CRP/apoA-I at admission were 0.84 and 0.83, respectively. Moreover, patients with high ratios of CRP/HDL-C (＞77.39) or CRP/apoA-I (＞72.37) had higher mortality rates during hospitalization (log-rank p < 0.001). Logistic regression analysis demonstrated that hypertension, lactate dehydrogenase, SOFA score, and High CRP/HDL-C ratio were independent predictors of in-hospital mortality.

Conclusions

During severe COVID-19, HDL-C and apoA-I concentrations are dramatically decreased in non-survivors. Moreover, High CRP/HDL-C ratio is significantly associated with an increase in mortality and a poor prognosis.

Gene expression profiling of sepsis-associated acute kidney injury

Sepsis accounts for more than 50% of all acute kidney injury (AKI) cases, and the combination of sepsis and AKI increases the risk of mortality from sepsis alone. However, to the best of our knowledge, the specific mechanism by which sepsis causes AKI has not yet been fully elucidated, and there is no targeted therapy for sepsis-associated AKI (SA-AKI). The present study investigated gene expression profiles using RNA sequencing (RNA-Seq) and bioinformatics analyses to assess the function of differentially expressed genes (DEGs) and the molecular mechanisms relevant to the prognosis of SA-AKI. From the bioinformatics analysis, 2,256 downregulated and 3,146 upregulated genes were identified (false discovery rate <0.1 and fold-change >2). Gene Ontology analysis revealed that the genes were enriched in cellular metabolic processes, cell death and apoptosis. The enriched transcription factors were v-rel reticuloendotheliosis viral oncogene homolog A and signaling transducer and activator of transcription 3. The enriched microRNAs (miRNAs or miRs) among the DEGs were miR-30e, miR-181a, miR-340, miR-466d and miR-466l. Furthermore, the enriched pathways included toll-like receptor signaling, nod-like receptor signaling and the Janus kinase/STAT signaling pathway. In conclusion, the present study identified certain prognosis-related genes, transcription factors, miRNAs and pathways by analyzing gene expression profiles of SA-AKI using RNA-Seq, which provides some basis for future experimental studies.

High-Density Lipoproteins Are Bug Scavengers

Lipoproteins were initially defined according to their composition (lipids and proteins) and classified according to their density (from very low- to high-density lipoproteins—HDLs). Whereas their capacity to transport hydrophobic lipids in a hydrophilic environment (plasma) is not questionable, their primitive function of cholesterol transporter could be challenged. All lipoproteins are reported to bind and potentially neutralize bacterial lipopolysaccharides (LPS); this is particularly true for HDL particles. In addition, HDL levels are drastically decreased under infectious conditions such as sepsis, suggesting a potential role in the clearance of bacterial material and, particularly, LPS. Moreover, "omics" technologies have unveiled significant changes in HDL composition in different inflammatory states, ranging from acute inflammation occurring during septic shock to low-grade inflammation associated with moderate endotoxemia such as periodontal disease or obesity. In this review, we will discuss HDL modifications associated with exposure to pathogens including bacteria, viruses and parasites, with a special focus on sepsis and the potential of HDL therapy in this context. Low-grade inflammation associated with atherosclerosis, periodontitis or metabolic syndrome may also highlight the protective role of HDLs in theses pathologies by other mechanisms than the reverse transport of cholesterol.

Presentation and outcomes of end stage liver disease patients presenting with septic shock to the emergency department

BACKGROUND

Patients with end stage liver disease (ESLD) are particularly vulnerable to sepsis. ESLD patients are often excluded from controlled sepsis trials and more data are needed to guide the management of this population.

OBJECTIVE

To describe the clinical factors and outcomes of patients with ESLD presenting to the emergency department (ED) with septic shock.

METHODS

We performed a retrospective review of patients registered in our dedicated ED adult septic shock pathway. All patients registered between January 2014 and May 2016 were included. Clinical and treatment variables for ESLD patients were compared with non-ESLD patients. A second analysis assessed ESLD survivors compared to non-survivors.

RESULTS

2,584 septic shock patients were enrolled. ESLD was present in 6.2% (n = 161) of patients. Patients with ESLD had higher mortality compared to patients without ESLD 36.6% vs 21.2% (p < 0.001). ESLD patients were more likely to be younger, female, obese, and have other comorbidities. ESLD patients exhibited lower temperature, higher lactate, and higher incidence of acute kidney injury. There was no difference in antibiotics or fluid resuscitation between groups. ESLD patients received more ED vasopressor support. Among ESLD septic shock patients, maximum lactate and presence of pneumonia were independently associated with death.

CONCLUSIONS

Patients with ESLD comprise a small but important subgroup of patients with ED septic shock that experience high mortality compared to patients without ESLD. Maximum ED lactate and pneumonia as the source of sepsis are independently associated with adverse outcome and may be used for early recognition of high-risk ESLD sepsis patients.

CREBH Regulates Systemic Glucose and Lipid Metabolism

The cyclic adenosine monophosphate (cAMP)-responsive element-binding protein H (CREBH, encoded by CREB3L3) is a membrane-bound transcriptional factor that primarily localizes in the liver and small intestine. CREBH governs triglyceride metabolism in the liver, which mediates the changes in gene expression governing fatty acid oxidation, ketogenesis, and apolipoproteins related to lipoprotein lipase (LPL) activation. CREBH in the small intestine reduces cholesterol transporter gene Npc1l1 and suppresses cholesterol absorption from diet. A deficiency of CREBH in mice leads to severe hypertriglyceridemia, fatty liver, and atherosclerosis. CREBH, in synergy with peroxisome proliferator-activated receptor α (PPARα), has a crucial role in upregulating Fgf21 expression, which is implicated in metabolic homeostasis including glucose and lipid metabolism. CREBH binds to and functions as a co-activator for both PPARα and liver X receptor alpha (LXRα) in regulating gene expression of lipid metabolism. Therefore, CREBH has a crucial role in glucose and lipid metabolism in the liver and small intestine.

Abnormalities of Lipoprotein Levels in Liver Cirrhosis: Clinical Relevance

Progressive lipoprotein impairment occurs in liver cirrhosis and is associated with increased morbidity and mortality. The present review aims to summarize the current evidence regarding the prognostic value of lipoprotein abnormalities in liver cirrhosis and to address the need of a better prognostic stratification of patients, including lipoprotein profile assessment. Low levels of lipoproteins are usual in cirrhosis. Much evidence supports the prognostic role of hypolipidemia in cirrhotic patients. In particular, hypocholesterolemia represents an independent predictor of survival in cirrhosis. In cirrhotic patients, lipoprotein impairment is associated with several complications: infections, malnutrition, adrenal function, and spur cell anemia. Alterations of liver function are associated with modifications of circulating lipids. Decreased levels of lipoproteins significantly impact the survival of cirrhotic patients and play an important role in the pathogenesis of some cirrhosis-related complications.

Apolipoprotein A-I: A favorable prognostic marker in infective endocarditis

BACKGROUND

Decreased apolipoprotein A-I (apoA-I) and high-density lipoprotein cholesterol (HDL-C) are common in inflammation and sepsis. No study with a large sample size has been performed to investigate the prognostic value of apoA-I or HDL-C in infective endocarditis (IE).

OBJECTIVE

The present study aimed to explore the prognostic value of apoA-I and HDL-C for adverse outcomes in IE patients.

METHODS

Patients with a definite diagnosis of IE between January 2009 and July 2015 were enrolled and divided into 3 groups according to their apoA-I tertiles at admission. Univariate and multivariate analyses were performed to evaluate the relationship of apoA-I and HDL-C with clinical outcomes.

RESULTS

Of the 593 included patients, 40 (6.7%) died in hospital. Patients with lower apoA-I experienced markedly higher rates of in-hospital mortality (10.7%, 7.0%, and 2.5% in tertiles 1-3, respectively; P = .006) and major adverse clinical events (32.5%, 24.1%, and 8.6% in tertiles 1-3, respectively; P < .001). ApoA-I (area under the curve, 0.671; P < .001) and HDL-C (area under the curve, 0.672; P < .001) had predictive values for in-hospital death. Multivariate logistic regression showed that apoA-I <0.90 g/L and HDL-C <0.78 mmol/L were independent risk predictors for in-hospital death. A multivariate Cox proportional hazard analysis revealed that apoA-I (increments of 1 g/L; hazard ratio, 0.36; 95% confidence interval, 0.15-0.87; P = .023) and HDL-C (increments of 1 mmol/L; hazard ratio, 0.38; 95% confidence interval, 0.18-0.83; P = .015) were independently associated with long-term mortality.

CONCLUSIONS

ApoA-I and HDL-C were inversely associated with adverse IE prognosis.

Sepsis in alcohol-related liver disease

Alcohol-related liver disease (ALD) remains the most important cause of death due to alcohol. Infections, particularly bacterial infections, are one of the most frequent and severe complications of advanced ALDs, such as alcoholic cirrhosis and severe alcoholic hepatitis (sAH). The specific mechanisms responsible for this altered host defence are yet to be deciphered. The aim of the present study is to review the current knowledge of infectious complications in ALD and its pathophysiological mechanisms, distinguishing the role of alcohol consumption and the contribution of different forms of ALD. To date, corticosteroids are the only treatment with proven efficacy in sAH, but their impact on the occurrence of infections remains controversial. The combination of an altered host defence and corticosteroid treatment in sAH has been suggested as a cause of opportunistic fungal and viral infections. A high level of suspicion with systematic screening and prompt, adequate treatment are warranted to improve outcomes in these patients. Prophylactic or preemptive strategies in this high-risk population might be a preferable option, because of the high short-term mortality rate despite adequate therapies. However, these strategies should be assessed in well-designed trials before clinical implementation.

Dehydroepiandrosterone sulfate and dehydroepiandrosterone sulfate/cortisol ratio in cirrhotic patients with septic shock: another sign of hepatoadrenal syndrome?

BACKGROUND

Cirrhotic patients are susceptible to sepsis and critical illness-related corticosteroid insufficiency (CIRCI). Dehydroepiandrosterone sulfate (DHEAS) is a corticotropin-dependent adrenal androgen, which has immunostimulating and antiglucocorticoid effects. Considering the synchronized synthesis of cortisol and DHEAS and their opposing effects to each other, investigators have proposed measuring these two hormones as a ratio. Severe sepsis has been associated with low DHEAS, especially relative to high cortisol. Despite growing interest in the role of adrenal androgen replacement in critical illness, there have been no data about DHEAS and the DHEAS/cortisol ratio in patients with liver cirrhosis. We studied whether low concentrations of DHEAS and decreased DHEAS/cortisol ratio are associated with poor outcome in patients with liver cirrhosis and septic shock.

METHODS

We recruited 46 cirrhotic patients with septic shock, and 46 noncirrhotic counterparts matched by age and sex. We evaluated adrenal function using the short corticotropin stimulation test and analyzed the relation between DHEAS and cortisol.

RESULTS

While the nonsurvivors in the cirrhotic group had significantly lower baseline DHEAS, lower baseline DHEAS/cortisol ratio, and reduced increments of both DHEAS and cortisol upon corticotropin stimulation, the survivors had lower baseline cortisol. Cirrhotic patients with lower DHEAS/cortisol ratio (<1.50) had higher levels of interleukin-6 and tumor necrosis factor alpha, higher Sequential Organ Failure Assessment scores, and higher rates of CIRCI and hospital mortality. Using the area under the receiver operating characteristic (AUROC) curve, both DHEAS and the DHEAS/cortisol ratio demonstrated a good discriminative power for predicting hospital survival (AUROC 0.807 and 0.925 respectively). The cirrhotic group had lower DHEAS and DHEAS/cortisol ratio but higher rates of CIRCI and hospital mortality, compared to the noncirrhotic group.

CONCLUSIONS

There is dissociation between cortisol (increased) and DHEAS (decreased) in those cirrhotic patients who succumb to septic shock. Low DHEAS/cortisol ratios are associated with more severe diseases, inflammation, and CIRCI and can serve as a prognostic marker. More investigations are needed to evaluate the role of adrenal androgen in this clinical setting.

慢加急性肝衰竭: 东西方诊断和预后的差异

慢加急性肝衰竭(acute-on-chronic liver failure, ACLF)是以慢性肝病基础上发生的急性肝功能失代偿和短期高死亡率为主要临床特征的一种可逆的、复杂的临床综合征. 由于不同区域ACLF的病因不同, 且病理机制复杂, 导致东西方对ACLF的定义及诊断标准仍存在争议, 且缺乏公认的预后评估体系. 近年来, ACLF引起了国内外学者的广泛关注, 取得了一些重要的研究进展, 本文将围绕国际上ACLF的最新进展, 对ACLF的定义及预后评估等进行分析总结.

Plasma Apolipoprotein A-V Predicts Long-term Survival in Chronic Hepatitis B Patients with Acute-on-Chronic Liver Failure

Hepatitis B virus-related acute-on-chronic liver failure (HBV-ACLF) is a life-threatening condition, and the lipid metabolism disorder is common in the development of this disease. This prospective observational study aimed to define the characteristics of plasma apolipoprotein A-V (apoA-V) in long-term outcome prediction of HBV-ACLF, and a total of 330 HBV-ACLF patients were included and followed for more than 12 months. In this cohort, the 4-week, 12-week, 24-week and 48-week cumulative mortality of HBV-ACLF was 18.2%(60/330), 50.9%(168/330), 59.7%(197/330) and 63.3%(209/330), respectively. As compared to survivors, the non-survivors had significantly lower concentrations of plasma apoA-V on admission. Plasma apoA-V concentrations were positively correlated with prothrombin time activity (PTA), and negatively correlated with interleukin-10, tumor necrosis factor-α, and iMELD scores. Though plasma apoA-V, PTA, total bilirubin(TBil) and blood urea nitrogen(BUN) were all independent factors to predict one-year outcomes of HBV-ACLF, plasma apoA-V had the highest prediction accuracy. And its optimal cutoff value for one-year survival prediction was 480.00 ng/mL, which had a positive predictive value of 84.68% and a negative predictive value of 92.23%. In summary, plasma apoA-V decreases significantly in non-survivors of HBV-ACLF, and it may be regarded as a new predictive marker for the prognosis of patients with HBV-ACLF.

Lycopene pretreatment improves hepatotoxicity induced by acetaminophen in C57BL/6 mice

Acetaminophen (APAP) is an antipyretic and analgesic drug that, in high doses, leads to severe liver injury and potentially death. Oxidative stress is an important event in APAP overdose. Researchers are looking for natural antioxidants with the potential to mitigate the harmful effects of reactive oxygen species in different models. Lycopene has been widely studied for its antioxidant properties. The aim of this study was to evaluate the antioxidant potential of lycopene pretreatment in APAP-induced liver injury in C57BL/6 mice. C57BL/6 male mice were divided into the following groups: control (C); sunflower oil (CO); acetaminophen 500mg/kg (APAP); acetaminophen 500mg/kg+lycopene 10mg/kg (APAP+L10), and acetaminophen 500mg/kg+lycopene 100mg/kg (APAP+L100). Mice were pretreated with lycopene for 14 consecutive days prior to APAP overdose. Analyses of blood serum and livers were performed. Lycopene was able to improve redox imbalance, decrease thiobarbituric acid reactive species level, and increase CAT and GSH levels. In addition, it decreased the IL-1β expression and the activity of MMP-2. This study revealed that preventive lycopene consumption in C57BL/6 mice can attenuate the effects of APAP-induced liver injury. Furthermore, by improving the redox state, and thus indicating its potential antioxidant effect, lycopene was also shown to have an influence on inflammatory events.

Toll-like Receptor (TLR) Signaling Interacts with CREBH to Modulate High-density Lipoprotein (HDL) in Response to Bacterial Endotoxin

Bacterial endotoxin can induce inflammatory and metabolic changes in the host. In this study, we revealed a molecular mechanism by which a stress-inducible, liver-enriched transcription factor, cAMP-responsive element-binding protein hepatic-specific (CREBH), modulates lipid profiles to protect the liver from injuries upon the bacterial endotoxin lipopolysaccharide (LPS). LPS challenge can activate CREBH in mouse liver tissues in a toll-like receptor (TLR)/MyD88-dependent manner. Upon LPS challenge, CREBH interacts with TNF receptor-associated factor 6 (TRAF6), an E3 ubiquitin ligase that functions as a key mediator of TLR signaling, and this interaction relies on MyD88. Further analysis demonstrated that TRAF6 mediates K63-linked ubiquitination of CREBH to facilitate CREBH cleavage and activation. CREBH directly activates expression of the gene encoding Apolipoprotein A4 (ApoA4) under LPS challenge, leading to modulation of high-density lipoprotein (HDL) in animals. CREBH deficiency led to reduced production of circulating HDL and increased liver damage upon high-dose LPS challenge. Therefore, TLR/MyD88-dependent, TRAF6-facilitated CREBH activation represents a mammalian hepatic defense response to bacterial endotoxin by modulating HDL.

CETP Lowers TLR4 Expression Which Attenuates the Inflammatory Response Induced by LPS and Polymicrobial Sepsis

Sepsis is a systemic inflammatory response to infection eliciting high mortality rate which is a serious health problem. Despite numerous studies seeking for therapeutic alternatives, the mechanisms involved in this disease remain elusive. In this study we evaluated the influence of cholesteryl ester transfer protein (CETP), a glycoprotein that promotes the transfer of lipids between lipoproteins, on the inflammatory response in mice. Human CETP transgenic mice were compared to control mice (wild type, WT) after polymicrobial sepsis induced by cecal ligation and puncture (CLP), aiming at investigating their survival rate and inflammatory profiles. Macrophages from the peritoneal cavity were stimulated with LPS in the presence or absence of recombinant CETP for phenotypic and functional studies. In comparison to WT mice, CETP mice showed higher survival rate, lower IL-6 plasma concentration, and decreased liver toll-like receptor 4 (TLR4) and acyloxyacyl hydrolase (AOAH) protein. Moreover, macrophages from WT mice to which recombinant human CETP was added decreased LPS uptake, TLR4 expression, NF-κB activation and IL-6 secretion. This raises the possibility for new therapeutic tools in sepsis while suggesting that lowering CETP by pharmacological inhibitors should be inconvenient in the context of sepsis and infectious diseases.

LIPID PROFILE OF CIRRHOTIC PATIENTS AND ITS ASSOCIATION WITH PROGNOSTIC SCORES: a cross-sectional study

BACKGROUND

In cirrhosis the production of cholesterol and lipoproteins is altered.

OBJECTIVE

Evaluate the lipid profile by measuring total cholesterol, very low-density lipoprotein, low-density lipoprotein, high-density lipoprotein and triglyceride levels in patients with cirrhosis caused by alcoholism and/or hepatitis C virus infection and determine its association with Child-Pugh and MELD scores.

METHODS

Cross-sectional retrospective study of patients treated at the outpatient clinic in Porto Alegre, Brazil, from 2006 to 2010.

RESULTS

In total, 314 records were reviewed, and 153 (48.7%) met the inclusion criteria, of which 82 (53.6%) had cirrhosis that was due to hepatitis C virus infection, 50 (32.7%) were due to alcoholism, and 21 (13.7%) were due to alcoholism and hepatitis C virus infection. The total cholesterol levels diminished with a Child-Pugh progression (P<0.001). Child-Pugh C was significantly associated with lover levels of low-density lipoprotein (<70 mg/dL; P<0.001), high-density lipoprotein (<40 mg/dL; P<0.001) and triglyceride (<70 mg/dL; P=0.003). MELD>20 was associated with lower total cholesterol levels (<100mg/dL; P<0.001), very low-density lipoprotein (<16 mg/dL; P=0.006), and low-density lipoprotein (<70 mg/dL; P=0.003). Inverse and statistically significant correlations were observed between Child-Pugh and all the lipid fractions analyzed (P<0.001). The increase in MELD was inversely correlated with reduced levels in total cholesterol (P<0.001), high-density lipoprotein (P<0.001), low-density lipoprotein (P<0.001), very low-density lipoprotein (P=0.030) and triglyceride (P=0.003).

CONCLUSION

A reduction in the lipid profile in patients with cirrhosis due to hepatitis C virus infection and/or alcoholism was significantly associated with the Child-Pugh and MELD prognostic markers. These results suggest that the lipid profile may be used as a tool to assist in evaluating liver disease.

Sphingosine 1-phosphate and its carrier apolipoprotein M in human sepsis and in Escherichia coli sepsis in baboons

Sphingosine 1‐phosphate (S1P) is an important regulator of vascular integrity and immune cell migration, carried in plasma by high‐density lipoprotein (HDL)‐associated apolipoprotein M (apoM) and by albumin. In sepsis, the protein and lipid composition of HDL changes dramatically. The aim of this study was to evaluate changes in S1P and its carrier protein apoM during sepsis. For this purpose, plasma samples from both human sepsis patients and from an experimental Escherichia coli sepsis model in baboons were used. In the human sepsis cohort, previously studied for apoM, plasma demonstrated disease‐severity correlated decreased S1P levels, the profile mimicking that of plasma apoM. In the baboons, a similar disease‐severity dependent decrease in plasma levels of S1P and apoM was observed. In the lethal E. coli baboon sepsis, S1P decreased already within 6–8 hrs, whereas the apoM decrease was seen later at 12–24 hrs. Gel filtration chromatography of plasma from severe human or baboon sepsis on Superose 6 demonstrated an almost complete loss of S1P and apoM in the HDL fractions. S1P plasma concentrations correlated with the platelet count but not with erythrocytes or white blood cells. The liver mRNA levels of apoM and apoA1 decreased strongly upon sepsis induction and after 12 hr both were almost completely lost. In conclusion, during septic challenge, the plasma levels of S1P drop to very low levels. Moreover, the liver synthesis of apoM decreases severely and the plasma levels of apoM are reduced. Possibly, the decrease in S1P contributes to the decreased endothelial barrier function observed in sepsis.

Early warning and clinical outcome prediction of acute-on-chronic hepatitis B liver failure

Hepatitis B virus (HBV) associated acute-on-chronic liver failure (ACLF) is an increasingly recognized fatal liver disease encompassing a severe acute exacerbation of liver function in patients with chronic hepatitis B (CHB). Despite the introduction of an artificial liver support system and antiviral therapy, the short-term prognosis of HBV-ACLF is still extremely poor unless emergency liver transplantation is performed. In such a situation, stopping or slowing the progression of CHB to ACLF at an early stage is the most effective way of reducing the morbidity and mortality of HBV-ACLF. It is well-known that the occurrence and progression of HBV-ACLF is associated with many factors, and the outcomes of HBV-ACLF patients can be significantly improved if timely and appropriate interventions are provided. In this review, we highlight recent developments in early warning and clinical outcome prediction in patients with HBV-ACLF and provide an outlook for future research in this field.

HDL in sepsis - risk factor and therapeutic approach

High-density lipoprotein (HDL) is a key component of circulating blood and plays essential roles in regulation of vascular endothelial function and immunity. Clinical data demonstrate that HDL levels drop by 40-70% in septic patients, which is associated with a poor prognosis. Experimental studies using Apolipoprotein A-I (ApoAI) null mice showed that HDL deficient mice are susceptible to septic death, and overexpressing ApoAI in mice to increase HDL levels protects against septic death. These clinical and animal studies support our hypothesis that a decrease in HDL level is a risk factor for sepsis, and raising circulating HDL levels may provide an efficient therapy for sepsis. In this review, we discuss the roles of HDL in sepsis and summarize the efforts of using synthetic HDL as a potential therapy for sepsis.

Adrenal insufficiency in patients with decompensated cirrhosis

Adrenal reserve depletion and overstimulation of the hypothalamus-pituitary-adrenal (HPA) axis are causes for adrenal insufficiency (AI) in critically ill individuals. Cirrhosis is a predisposing condition for AI in cirrhotics as well. Both stable cirrhotics and liver transplant patients (early and later after transplantation) have been reported to present AI. The mechanisms leading to reduced cortisol production in cirrhotics are the combination of low cholesterol levels (the primary source of cortisol), the increased cytokines production that overstimulate and exhaust HPA axis and the destruction of adrenal glands due to coagulopathy. AI has been recorded in 10%-82% cirrhotics depending on the test used to evaluate adrenal function and in 9%-83% stable cirrhotics. The similarity of those proportions support the assumption that AI is an endogenous characteristic of liver disease. However, the lack of a gold standard method for AI assessment and the limitation of precise thresholds in cirrhotics make difficult the recording of the real prevalence of AI. This review aims to summarize the present data over AI in stable, critically ill cirrhotics and liver transplant recipients. Moreover, it provides information about the current knowledge in the used diagnostic tools and the possible effectiveness of corticosteroids administration in critically ill cirrhotics with AI.

Serum levels of apolipoprotein A-I and high-density lipoprotein can predict organ failure in acute pancreatitis

Introduction

Predicting severity of pancreatitis is an important goal. Clinicians are still searching for novel and simple biomarkers that can better predict persistent organ failure (OF). Lipoproteins, especially high-density lipoprotein (HDL), and apolipoprotein A-I (APO A-I), have been shown to have anti-inflammation effects in various clinical settings. Severe acute pancreatitis (SAP) is associated with hypo-lipoproteinemia. We studied whether the concentrations of HDL and APO A-I can predict persistent OF in patients with predicted SAP admitted to the ICU.

Methods

In 66 patients with predicted SAP, we prospectively evaluated the relationship between lipid levels, inflammatory cytokines and clinical outcomes, including persistent OF and hospital mortality. Blood samples were obtained within 24 hours of admission to the ICU.

Results

HDL and APO A-I levels were inversely correlated with various disease severity scores. Patients with persistent OF had lower levels of HDL and APO A-I, while those with transient OF had lower levels of interleukin-6, tumor necrosis factor-α and lower rates of hospital mortality. Meanwhile, hospital non-survivors had lower concentrations of HDL, and APO A-I compared to the survivors. By using the area under the receiver operating characteristic (AUROC) curve, both HDL and APO A-I demonstrated an excellent discriminative power for predicting persistent OF among all patients (AUROC 0.912 and 0.898 respectively) and among those with OF (AUROC 0.904 and 0.895 respectively). Pair-wise comparison of AUROC showed that both HDL and APO A-I had better discriminative power than C-reactive protein to predict persistent OF.

Conclusions

Serum levels of HDL and APO A-I at admission to the ICU are inversely correlated with disease severity in patients with predicted SAP and can predict persistent OF in this clinical setting.

Electronic supplementary material

The online version of this article (doi:10.1186/s13054-015-0832-x) contains supplementary material, which is available to authorized users.

Apolipoprotein AI and HDL are reduced in stable cirrhotic patients with adrenal insufficiency: a possible role in glucocorticoid deficiency

BACKGROUNDS AND AIMS

Adrenal insufficiency (AI) has been reported in patients with stable cirrhosis. A lack of substrates has been suggested as a possible contributing pathogenic mechanism leading to glucocorticoid deficiency in these subjects. To better explore this hypothesis, we studied lipoproteins in cirrhotics with and without AI.

METHODS

A total of 81 cirrhotic patients and 30 normal volunteers were enrolled. The severity of liver disease was graded by Child-Pugh score. Total cholesterol (TC), high-density lipoprotein (HDL), low-density lipoprotein (LDL), triglyceride (TG), and apolipoprotein AI (Apo-AI) levels were evaluated. HDL subfractions were measured by gradient gel electrophoresis. Adrenal function was assessed by the Low-Dose Short Synacthen Test.

RESULTS

Cirrhotic patients showed a significant reduction of TC, HDL, LDL, TG, and Apo-AI levels compared with controls. HDL3 was significantly lower, while HDL2 was higher, in cirrhotics compared with the controls. AI was observed in 26 patients. TC, TG, HDL, and Apo-AI were significantly reduced in cirrhotics with AI compared with those with normal adrenal function. HDL2 and HDL3 did not differ between these two groups. Delta cortisol was related to TC (r = 0.30, p < 0.01), TG (r = 0.22, p = 0.05), and Apo-AI (r = 0.37, p < 0.001). Multivariate analysis revealed that Apo-AI and HDL were independently associated with AI.

CONCLUSION

Our study shows that TC, TG, HDL, and Apo-AI are reduced in cirrhotics with AI. In particular, because both HDL and Apo-AI play a primary role in providing substrates for steroidogenesis to adrenal cells, this deficiency may contribute to the pathogenesis of AI in these patients.

Critical illness-related corticosteroid insufficiency in cirrhotic patients with acute gastroesophageal variceal bleeding: risk factors and association with outcome*

OBJECTIVES

Critical illness-related corticosteroid insufficiency can adversely influence the prognosis of critically ill patients. However, its impact on the outcomes of patients with cirrhosis and acute gastroesophageal variceal bleeding remains unknown. We evaluated adrenal function using short corticotropin stimulation test in patients with cirrhosis and gastroesophageal variceal bleeding. The main outcomes analyzed were 5-day treatment failure and 6-week mortality.

DESIGN

Prospective observational study.

SETTING

Ten-bed gastroenterology-specific medical ICU at a 3,613-bed university teaching hospital in Taiwan.

PATIENTS

Patients with liver cirrhosis and acute gastroesophageal variceal bleeding.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

We evaluated adrenal function using short corticotropin stimulation test in 157 episodes of gastroesophageal variceal bleeding in 143 patients with cirrhosis. Critical illness-related corticosteroid insufficiency occurred in 29.9% of patients. The patients with critical illness-related corticosteroid insufficiency had higher rates of treatment failure and 6-week mortality (63.8% vs 10.9%, 42.6% vs 6.4%, respectively; p < 0.001). The cumulative rates of survival at 6 weeks were 57.4% and 93.6% for the critical illness-related corticosteroid insufficiency group and normal adrenal function group, respectively (p < 0.001). The cortisol response to corticotropin was inversely correlated with Model for End-Stage Liver Disease and Child-Pugh scores and positively correlated with the levels of high-density lipoprotein and total cholesterol. Hypovolemic shock, high-density lipoprotein, platelet count, and bacterial infection at inclusion are independent factors predicting critical illness-related corticosteroid insufficiency, whereas critical illness-related corticosteroid insufficiency, Model for End-Stage Liver Disease score, hypovolemic shock, hepatocellular carcinoma, and active bleeding at endoscopy are independent factors to predict treatment failure. Multivariate analysis also identified Model for End-Stage Liver Disease score, hypovolemic shock, and bacterial infection at inclusion as independent factors associated with 6-week mortality.

CONCLUSIONS

Critical illness-related corticosteroid insufficiency is common in cirrhotic patients with acute gastroesophageal variceal bleeding and is an independent factor to predict 5-day treatment failure.

Intensive care unit management of patients with liver failure

Acute liver failure (ALF) and acute-on-chronic liver failure (ACLF) usually mandate management within an intensive care unit (ICU). Even though the conditions bear some similarities, precipitating causes, and systemic complications management practices differ. Although early identification of ALF and ACLF, improvements in ICU management, and the widespread availability of liver transplantation have improved mortality, optimal management practices have not been defined. This article summarizes current ICU management practices and identifies areas of management that require further study.

Low levels of blood lipids are associated with etiology and lethal outcome in acute liver failure

BACKGROUND/AIMS

Emerging data links different aspects of lipid metabolism to liver regeneration. In patients with acute liver failure (ALF), low levels of lipids may correlate with disease severity. Thus, we determined whether there is an etiology-specific link between lipid levels in patients suffering from ALF and aimed to investigate an effect of lipid levels on the prognosis of ALF.

METHODS

In this retrospective single center study, we reviewed 89 consecutive ALF patients, who met the criteria of the "Acute Liver Failure Study Group". Patient characteristics, clinical data and laboratory parameters were individually analyzed at admission and correlated with the patients' outcome after a four week follow up. Possible endpoints were either discharge, or death or liver transplantation.

RESULTS

High-density lipoprotein (HDL), cholesterol and triglyceride levels were significantly lower in patients who died or required a liver transplant. HDL levels were significantly higher in patients with ALF caused by acetaminophen intoxication, compared to fulminant HBV infection or drug induced liver injury. HDL levels correlated with hepatic injury by ALT levels, and Albumin, and inversely correlated with the MELD score, INR, and bilirubin.

CONCLUSION

In our cohort of patients with ALF, we could show that HDL and cholesterol are suppressed. In addition novel etiology specific patterns between acteminophen and non-acteminophen induced liver failure were detected for serum lipid components. Further studies are needed to address the role of cholesterol and lipid metabolism and the according pathways in different etiologies of ALF.

High density lipoprotein protects against polymicrobe-induced sepsis in mice

HDL has been considered to be a protective factor in sepsis; however, most contributing studies were conducted using the endotoxic animal model, and evidence from clinically relevant septic animal models remains limited and controversial. Furthermore, little is known about the roles of HDL in sepsis other than LPS neutralization. In this study, we employed cecal ligation and puncture (CLP), a clinically relevant septic animal model, and utilized apoA-I knock-out (KO) and transgenic mice to elucidate the roles of HDL in sepsis. ApoA-I-KO mice were more susceptible to CLP-induced septic death as shown by the 47.1% survival of apoA-I-KO mice versus the 76.7% survival of C57BL/6J (B6) mice (p = 0.038). ApoA-I-KO mice had exacerbated inflammatory cytokine production during sepsis compared with B6 mice. Further study indicated that serum from apoA-I-KO mice displayed less capacity for LPS neutralization compared with serum from B6 mice. In addition, apoA-I-KO mice had less LPS clearance, reduced corticosterone generation, and impaired leukocyte recruitment in sepsis. In contrast to apoA-I-KO mice, apoA-I transgenic mice were moderately resistant to CLP-induced septic death compared with B6 mice. In conclusion, our findings reveal multiple protective roles of HDL in CLP-induced sepsis. In addition to its well established role in neutralization of LPS, HDL exerts its protection against sepsis through promoting LPS clearance and modulating corticosterone production and leukocyte recruitment. Our study supports efforts to raise HDL levels as a therapeutic approach for sepsis.

Acute renal failure in cirrhotic patients with severe sepsis: value of urinary interleukin-18

BACKGROUND AND AIM

Acute renal failure (ARF) is a common complication of liver cirrhosis and severe sepsis. Differentiating functional renal failure from acute tubular necrosis (ATN) has been difficult in this clinical setting. It has been shown that urinary interleukin 18 (IL-18) can serve as a sensitive marker for ARF and ATN. This study was aimed to investigate the diagnostic and prognostic values of urinary IL-18 in ARF associated with liver cirrhosis and severe sepsis.

METHODS

We prospectively evaluated the relationship between urinary IL-18 and clinical outcomes in 168 consecutive cirrhotic patients with severe sepsis.

RESULTS

One hundred and eight patients (64.3%) developed ARF at admission to the intensive care unit. ARF was associated with higher urinary IL-18 and impaired effective arterial volume. Renal failure was functional in 64 (59.2%), due to acute tubular necrosis (ATN) in 30 (27.7%), and mixed type in 14 (12.9%). Patients with ATN had significantly higher levels of urinary IL-18, rates of vasopressor dependency, and hospital mortality than those with functional renal failure. By using the areas under receiver operating characteristic (AUROC) curve, urinary IL-18 demonstrated an excellent discriminative power (AUROC 0.882) for diagnosing tubular injury in those with ARF. Meanwhile, hospital survivors had significantly lower urinary and serum IL-18 levels, compared to non-survivors. In multivariate analysis, urinary IL-18, international normalized ratio, and mean arterial pressure were independent factors to predict hospital mortality.

CONCLUSIONS

Urinary IL-18 can serve as a diagnostic and prognostic marker in cirrhotic patients with severe sepsis.

The lipid-bound apolipoprotein A-I cysteine mutant (N74C) inhibits the activation of NF-κB, JNK and p38 in endotoxemic mice and RAW264.7 cells

Our previous studies showed that recombinant high-density lipoprotein (rHDL) rHDL74 exhibited higher anti-inflammatory capabilities compared to wild-type rHDL (rHDLwt), while rHDL228 showed hyper-proinflammation. In this paper, we further investigated the potential mechanisms involved in their different inflammatory functions using two models: endotoxemic mice and the RAW264.7 inflammation model. Our results showed that 24 h after the injection of lipopolysaccharide (LPS), mice treated with rHDL74 had a significant decrease in plasma CRP (P<0.01 vs. rHDLwt; P<0.01 vs. LPS), MCP-1 (P<0.05 vs. rHDLwt; P<0.01 vs. LPS) and CD14 (P<0.01 vs. LPS) compared with the mice treated with rHDLwt or the controls that received LPS only. Similar to our previous study, rHDL228 increased the plasma level of CRP (P<0.05 vs. LPS) and MCP-1 (P<0.01 vs. LPS). Our immunohistochemistry and western blot analysis showed that rHDL74 inhibited the activation of NF-κB in endotoxemic mice and JNK and p38 in the RAW264.7 inflammation model, while rHDL228 exacerbated the activation of NF-κB and ERK. In summary, our data suggest that rHDL74 exhibits higher anti-inflammatory activity by decreasing inflammatory factors and inhibiting the activation of NF-κB, JNK and p38, while rHDL228 appears to be hyper-proinflammation by increasing these inflammatory factors and aggravating the activation of NF-κB and ERK.

Body fat distribution and risk factors for fibrosis in patients with alcoholic liver disease

BACKGROUND

Only a small proportion of alcoholic patients develop advanced liver disease, suggesting that factors other than alcohol intake may influence alcoholic liver disease (ALD) progression. We have shown that body mass index (BMI) is an independent risk factor for fibrosis in alcohol-induced liver disease and that adipose tissue inflammation is correlated with liver lesions in alcoholic patients. The aim of this study was to determine whether visceral adipose tissue, as assessed by abdominal height measurement, affected individual susceptibility to fibrosis in alcoholic patients.

METHODS

We included 127 consecutive alcoholic patients with abnormal liver test findings for whom liver histology data were available. Abdominal height was measured with a Holtain-Kahn abdominal caliper. We carried out univariate comparisons followed by multivariate regression analysis, to investigate the relationship between abdominal height and fibrosis score.

RESULTS

Abdominal height (p < 0.005), waist circumference (p < 0.05), fasting blood glucose concentration (p < 0.05), serum triglyceride concentration (p < 0.05), serum bilirubin (p < 0.005), and BMI (p = 0.05) were higher, whereas high-density lipoprotein (HDL) cholesterol level (p < 0.01) was lower in the 72 patients with significant (F2-F4) fibrosis than in the 55 patients with F0-F1 fibrosis. In multivariate regression analysis, only abdominal height (β = 7.2, p < 0.002) was independently and positively correlated with fibrosis score, which was also negatively correlated with HDL cholesterol level (β = -1.04, p < 0.05).

CONCLUSIONS

We provide the first demonstration that abdominal height may be a predictor of significant fibrosis in patients with ALD. Our findings support a role for visceral fat accumulation, independent of BMI and of metabolic syndrome criteria, in the onset of alcoholic liver damage.

Management of critically-ill cirrhotic patients

Cirrhotic patients are prone to develop life-threatening complications that require emergency care and ICU admission. They can present specific decompensations related to cirrhosis such as variceal bleeding and hepatorenal syndrome (HRS) or other critical events also observed in the general population such as severe sepsis or septic shock. Clinical management of all these entities requires a specific approach in cirrhosis. Cirrhotic patients have a hyperdynamic circulation with high cardiac output and low systemic vascular resistance in the absence of infection. Circulatory dysfunction increases the susceptibility of critically-ill cirrhotic patients to develop multiple organ failure and attenuates vascular reactivity to vasopressor drugs. HRS, a severe functional renal failure occurring in patients with advanced cirrhosis and ascites, is also secondary to this circulatory dysfunction that leads to an extreme renal vasoconstriction. Moreover, hypotensive cirrhotic patients require a carefully balanced replacement of volemia, since overtransfusion increases portal hypertension and the risk of variceal bleeding and undertransfusion causes tissue hypoperfusion which increases the risk of multiple organ failure. Cirrhotic patients are also at a high risk for development of other bleeding complications and are more susceptible to nosocomial infections. This extreme complexity of critically-ill cirrhotic patients requires a specific medical approach that should be known by general intensivists since it has a negative impact on patient prognosis. This review will focus on the diagnostic approach and treatment strategies currently recommended in the critical care management of patients with cirrhosis.

Diagnostic accuracy of biomarkers measured in the hepatic vein and peripheral vein in the prediction of advanced fibrosis in patients with chronic viral hepatitis

OBJECTIVES

The accuracies of biomarkers checked in the hepatic vein (HV) and peripheral vein (PV) were compared in the prediction of advanced fibrosis (AF) of liver.

METHODS

Patients with chronic viral hepatitis (n=101) who underwent hepatic venous pressure gradient, liver biopsy, and paired HV-PV samples (6 biomarkers: hyaluronic acid [HA], haptoglobin, matrix metalloproteinase-2 [MMP2], tissue inhibitor of metalloproteinases-1 [TIMP1], procollagen III N-terminal peptide [PIIINP], and apolipoprotein-A1 [Apo-A1]) were enrolled.

RESULTS

Differences were displayed between the HV and PV in the predictive logit-models for predicting AF (-3.13+0.017×MMP2-0.019×haptoglobin and -0.270+0.007×HA-0.018×haptoglobin, respectively). In the area under the receiver operating characteristic curves, PIIINP (0.74/0.68, p=0.03), MMP2 (0.72/0.63, p=0.04), HA (0.79/0.76, p=0.94), Apo-A1 (0.56/0.48, p=0.73), and predictive logit-model (0.81/0.78, p=0.68) showed higher diagnostic value in the HV sample.

CONCLUSIONS

While most biomarkers were correlated better with hepatic fibrosis in HV than in PV, individually and in predictive logit-models, they were inadequate to determine the degree of advanced fibrosis.

High density lipoprotein in patients with liver failure; relation to sepsis, adrenal function and outcome of illness

BACKGROUND AND AIMS

High density lipoprotein (HDL) plays an important role in the transport of cholesterol to the adrenal gland for steroidogenesis and may have actions that modulate response to infection and critical illness. The clinical relevance of HDL level in patients with liver failure remains poorly characterised.

METHODS

In 164 critically-ill patients with acute (ALF) and acute on chronic liver failure (AOCLF) we evaluated the relationship between HDL levels measured on admission to intensive care unit (ICU) and survival, predisposition to sepsis and adrenocortical function assessed through the cortisol response to short synacthen testing (SST).

RESULTS

In acute liver failure and acute on chronic liver failure, high density lipoprotein levels were significantly lower in non-survivors (P < 0.01). Levels correlated closely with biochemical markers of liver function and the duration of liver failure. However, predictive accuracy was not superior to conventional markers and on multi-variate analysis did not show independent association with survival. Low HDL concentration was not associated with an increased incidence of sepsis either precipitating or complicating ICU admission. Evidence of adrenocortical insufficiency was present in more than half of patients undergoing SST and HDL level but not other lipid parameters correlated closely with cortisol increment after SST (r = 0.364, P < 0.0001).

CONCLUSIONS

High density lipoprotein levels are low in patients with liver failure and reflect its severity. Levels are lower in non-survivors but do not offer an advantage as early indicators of prognosis over conventional markers. No evidence of a major predisposing role for infection was found, but findings suggest a close link to adrenal function.