Acute-on-chronic and Decompensated Chronic Liver Failure: Definitions, Epidemiology, and Prognostication

Chimeric Livers: Interspecies Blastocyst Complementation and Xenotransplantation for End-Stage Liver Disease

Orthotopic liver transplantation (OLT) currently serves as the sole definitive treatment for thousands of patients suffering from end-stage liver disease; and the existing supply of donor livers for OLT is drastically outpaced by the increasing demand. To alleviate this significant gap in treatment, several experimental approaches have been devised with the aim of either offering interim support to patients waiting on the transplant list or bioengineering complete livers for OLT by infusing them with fresh hepatic cells. Recently, interspecies blastocyst complementation has emerged as a promising method for generating complete organs in utero over a short timeframe. When coupled with gene editing technology, it has brought about a potentially revolutionary transformation in regenerative medicine. Blastocyst complementation harbors notable potential for generating complete human livers in large animals, which could be used for xenotransplantation in humans, addressing the scarcity of livers for OLT. Nevertheless, substantial experimental and ethical challenges still need to be overcome to produce human livers in larger domestic animals like pigs. This review compiles the current understanding of interspecies blastocyst complementation and outlines future possibilities for liver xenotransplantation in humans.

Model for End Stage Liver Disease (MELD) Score: A Tool for Prognosis and Prediction of Mortality in Patients With Decompensated Liver Cirrhosis

BACKGROUND

Decompensated liver disease has become a common occurrence in medical wards. It has become the third most common cause of death in medical wards. This high mortality rate has become a matter of concern. It is important that a reliable scoring system helps to stratify patients with liver cirrhosis who will require liver transplantation.

OBJECTIVE

To determine the value of the Model for End-Stage Liver Disease (MELD) score in assessing the mortality of patients with decompensated liver cirrhosis over one month period (30 days).

METHODS AND MATERIALS

A longitudinal study was conducted. A total of 110 patients diagnosed with decompensated liver cirrhosis were recruited from the gastroenterology clinic and medical wards of the University of Benin Teaching Hospital (UBTH), Benin City. The patients were recruited consecutively and met the inclusion criteria for the study. Demographic data, history, clinical, biochemical, ultrasonographic, and liver biopsy findings were evaluated in the patients who participated in this study.  Results: The mean age of the patients was 57 ± 11.06 years. Out of the 110 study participants, a 2.9:1 male-to-female ratio was appreciated in the patient population, with a total of 82 males and 28 females. Multiple logistic regression analysis identified MELD scores as an independent predictor of mortality in the studied patients. Predictive values of the MELD score for 1-month mortality which was analyzed using the receiver operating characteristic (ROC) curves showed that the MELD score had a sensitivity of 72.2% and positive predictive value of 93.6% with an area under the curve of 0.926 for all-cause mortality among decompensated liver cirrhosis patients.

CONCLUSION

MELD score is a good predictor of mortality among patients with decompensated liver cirrhosis over a 1-month (30 days) period.

Quantification of chronic diseases presenting in the Emergency Department and their disposition outcomes: A hospital-based cross-sectional study in north India

A knowledge of the extent and distribution of chronic comorbidity plays an essential role in providing appropriate care, and allocating health resources to the patients admitted to the emergency department. We performed a cross-sectional study to quantify the chronic diseases presenting in the Emergency Department of PGIMER, Chandigarh (India). Out of 205 patients, 133 (64.9%) had pre-existing comorbidity. Common were chronic kidney disease (29, 14.1%), chronic liver disease (23, 11.2%), diabetes mellitus (21, 10.2%), malignancy (20, 9.8%), cardiac diseases (17, 8.3%), and chronic obstructive pulmonary disease (9, 4.4%). The median Charlson comorbidity index score was 2 (range, 0-9). In-hospital mortality was 43 (21%) and was predicted by older age (median, 60 v. 50 years; p-value, 0.017). Deaths with previous stroke (66.6%), chronic obstructive pulmonary disease (55.6%), and diabetes (28.6%) were higher than cardiac (2.3%) and renal (6.9%) comorbidity. Increasing comorbidity requires a shift in existing models of emergency care.

Proton Pump Inhibitor Therapy Increases the Risk of Spontaneous Bacterial Peritonitis in Patients with HBV-Related Acute-on-Chronic Liver Failure

INTRODUCTION

Spontaneous bacterial peritonitis (SBP) is a common infection in patients with hepatitis B virus (HBV)-related acute-on-chronic liver failure (ACLF). SBP significantly increases the mortality rate and medical costs. The association between proton pump inhibitor (PPI) use and SBP remains unclear. We conducted a retrospective study to investigate the association between PPI use and SBP in patients with HBV-related ACLF and to explore the risk factors for SBP.

METHODS

We compared the SBP incidence between the PPI and non-PPI groups before and after propensity score matching and explored the association between the duration and type of PPI and SBP occurrence. Risk factors for SBP occurrence were determined by univariate and multivariate logistic regression analysis.

RESULTS

The SBP incidence was higher in the PPI group than in the non-PPI group before and after propensity score matching. The SBP incidence increased for elevated MELD scores in PPI users. There was a similar SBP incidence in both different types and durations of PPI users. MELD score, old age, male sex, and high WBC count were significant independent risk factors for SBP in PPI users with HBV-related ACLF in the hospital.

CONCLUSIONS

PPI therapy increases the risk of SBP development in patients with HBV-related ACLF. MELD score, old age, male sex, and high WBC count could serve as predictors of SBP in PPI users. Caution should be taken regarding PPI use, especially for patients with MELD scores > 30.

Dissolved oxygen concentration regulates human hepatic organoid formation from pluripotent stem cells in a fully controlled bioreactor

Developing technologies for scalable production of human organoids has gained increased attention for "organoid medicine" and drug discovery. We developed a scalable and integrated differentiation process for generation of hepatic organoid from human pluripotent stem cells (hPSCs) in a fully controlled stirred tank bioreactor with 150 ml working volume by application of physiological oxygen concentrations in different liver tissue zones. We found that the 20-40% dissolved oxygen concentration [DO] (corresponded to 30-60 mmHg pO₂ within the liver tissue) significantly influences the process outcome via regulating the differentiation fate of hPSC aggregates by enhancing mesoderm induction. Regulation of the [DO] at 30% DO resulted in efficient generation of human fetal-like hepatic organoids that had a uniform size distribution and were comprised of red blood cells and functional hepatocytes, which exhibited improved liver-specific marker gene expressions, key liver metabolic functions, and, more important, higher inducible cytochrome P450 activity compared to the other trials. These hepatic organoids were successfully engrafted in an acute liver injury mouse model and produced albumin after implantation. These results demonstrated the significant impact of the dissolved oxygen concentration on hPSC hepatic differentiation fate and differentiation efficacy that should be considered ascritical translational aspect of established scalable liver organoid generation protocols for potential clinical and drug discovery applications.

Acute-on-chronic liver failure: management and prognosis

PURPOSE OF REVIEW

Hospitalizations due to complications of cirrhosis continue to rise. Patients with chronic liver disease who suffer acute decompensation [acute-on-chronic liver failure (ACLF)] often require intensive care support and are at high risk for short-term mortality. Given the high mortality rate associated with this condition is incumbent on intensive care providers who care for this patient population to have a working knowledge of ACLF with its associated complications, management strategies and prognosis.

RECENT FINDINGS

Recognizing ACLF as a distinct clinical entity has gained international attention in recent years though a consensus does not exist. There has been progress on better defining this clinical entity and recent studies have begun to address the critical care needs of these patients. Additional studies are required to define the best care practices for patients with ACLF.

SUMMARY

ACLF is a condition occurring in patients with chronic liver disease which is commonly associated with a need for intensive care support and carries a high risk of short-term mortality. Intensive care specialists must be familiar with diagnosis and management of this condition.

Human antigen R: A potential therapeutic target for liver diseases

Human antigen R (HuR), also known as HuA and embryonic lethal abnormal vision-like 1 (ELAVL1), is a ubiquitously expressed RNA binding protein and functions as an RNA regulator and mediates the expression of various proteins by diverse post-transcriptional mechanisms. HuR has been well characterized in the inflammatory responses and in the development of various cancers. The importance of HuR-mediated roles in cell signaling, inflammation, fibrogenesis and cancer development in the liver has attracted a great deal of attention. However, there is still a substantial gap between the current understanding of the potential roles of HuR in the progression of liver disease and whether HuR can be targeted for the treatment of liver diseases. In this review, we introduce the function and mechanistic characterization of HuR, and then focus on the physiopathological roles of HuR in the development of different liver diseases, including hepatic inflammation, alcoholic liver diseases, non-alcoholic fatty liver diseases, viral hepatitis, liver fibrosis and liver cancers. We also summarize existing approaches targeting HuR function. In conclusion, although characterizing the liver-specific HuR function and demonstrating the multi-level regulative networks of HuR in the liver are still required, emerging evidence supports the notion that HuR represents a potential therapeutic target for the treatment of chronic liver diseases.

Pre- and Peri-Operative Factors Associated with Chronic Critical Illness in Liver Transplant Recipients

Background: Chronic critical illness (CCI) is a new and increasing entity that accounts for substantial cost despite its low incidence. We hypothesized that patients with end-stage liver failure undergoing liver transplant would be at high risk for developing CCI. With limited liver donors it is essential to understand pre- and peritransplant predictors of CCI. Methods: To accomplish this we performed a retrospective cohort study at a large academic transplant center of all adult liver transplant patients from 2011 to 2017. We defined CCI as the need for mechanical ventilation for seven days or more post-transplant. Recipients who had re-transplantation during their index admission, acute rejection, or who died during transplant surgery were excluded. Logistic regression was performed using the Akaike information criterion (AIC) and the likelihood ratio test. Results: We identified 382 transplant recipients. Forty-five (11.8%) developed CCI. Univariable analysis identified 16 pre-transplant factors associated with post-transplant CCI. Subsequent multivariable logistic regression identified eight independent factors associated with CCI in liver transplant recipients including previous liver transplant, acute renal failure, frailty, lower albumin level, higher international normalized ratio, need for mechanical ventilation, and higher systolic pulmonary artery pressure. Pre-transplant factors associated with protection against CCI included higher Model for End-Stage Liver Disease (MELD) score. Conclusion: The incidence of CCI post-liver transplant is similar to the general population admitted to the intensive care unit. Pre-transplant factors associated with CCI can help identify at-risk patients, and furthermore, promote further research and interventions with the goal to decrease the incidence of CCI in the liver transplant recipients.

Acute-on-chronic liver failure: Objective admission and support criteria in the intensive care unit

Cirrhosis is a leading cause of morbidity and mortality throughout the world. Significant complications include variceal bleeding, hepatic encephalopathy, hepatorenal syndrome, and infection. When these complications are severe, admission to the intensive care unit (ICU) is often required for organ support and management. Intensive care therapy can also serve as a bridge to liver transplantation. Along with decompensation of cirrhosis, the concept of acute-on-chronic liver failure (ACLF) has emerged. This involves an acute precipitating event, such as the development of infection in a patient with cirrhosis, which leads to acute deterioration of hepatic function and extrahepatic organ failure. Extrahepatic complications often include renal, cardiovascular, and respiratory failures. Patients with significant extrahepatic and hepatic failures need ICU admission for organ support. Again, in patients who are deemed suitable liver transplant candidates, intensive care management may allow bridging to liver transplantation. However, patients with a Chronic Liver Failure Consortium ACLF score greater than 70 at 48 to 72 hours post-ICU admission do not seem to benefit from ongoing intensive support and a palliative approach may be more appropriate.

Nonacetaminophen Drug-Induced Acute Liver Failure

Acute liver failure of all causes is diagnosed in between 2000 and 2500 patients annually in the United States. Drug-induced acute liver failure is the leading cause of acute liver failure, accounting for more than 50% of cases. Nonacetaminophen drug injury represents 11% of all cases in the latest registry from the US Acute Liver Failure Study Group. Although rare, acute liver failure is clinically dramatic when it occurs, and requires a multidisciplinary approach to management. In contrast with acetaminophen-induced acute liver failure, non-acetaminophen-induced acute liver failure has a more ominous prognosis with a lower liver transplant-free survival.