Role of Toll-like receptor impairment in cirrhosis infection risk: are we making progress?

The LIVERAID (LIVER And Infectious Diseases)-ICU score predicts in-hospital mortality in liver cirrhosis patients with infections in the intensive care unit

OBJECTIVES

The admission of patients with liver cirrhosis to the intensive care unit (ICU) due to infections is a frequent occurrence, often leading to complications such as hepatic encephalopathy, renal failure and circulatory collapse, significantly elevating mortality risks. Accurate and timely diagnosis and intervention are critical for improving therapeutic outcomes. In this context, medical scoring systems in ICUs are essential for precise diagnosis, severity assessment and appropriate therapeutic strategies. There are no specific models for the prediction of mortality in ICU patients with liver cirrhosis-associated infections. This study aims to develop an improved prognostic scoring system for predicting in-hospital mortality among liver cirrhosis patients with infections in the ICU. This scoring system is designed to enhance the predictive accuracy of in-hospital mortality complementing existing sepsis and liver-specific prognostic models.

METHODS

A retrospective analysis was conducted in 620 patients with liver cirrhosis, treated for infections in the ICU of a German university hospital during 2017-19. Advanced statistical techniques were employed to develop and validate the LIVERAID (LIVER And Infectious Diseases)-ICU score, a novel scoring system specifically tailored for liver cirrhosis patients in the ICU with infections. The development of the multivariable logistic regression model involved selecting variables with the highest prognostic efficacy, and its predictive performance was assessed using calibration plots and the concordance statistic (c-index) to evaluate both calibration and discrimination.

RESULTS

The LIVERAID-ICU score integrates Child-Pugh class, serum urea levels and respiratory metrics. It is designed for bedside calculation using basic clinical and laboratory data, with no need for additional tools. In the validation cohort, the LIVERAID-ICU score exhibited enhanced sensitivity and specificity (AUC=0.83) in forecasting in-hospital mortality of patients with liver cirrhosis-associated infections when compared with established scores like Sequential Organ Failure Assessment (SOFA) (p=0.045), Model for End-Stage Liver Disease (MELD) (p=0.097), Child (p<0.001) and CLIF consortium acute-on-chronic liver failure (CLIF-C ACLF) (p<0.001).

CONCLUSION

The newly developed LIVERAID-ICU score represents a robust, streamlined and easy tool for predicting in-hospital mortality in liver cirrhosis patients with infections, surpassing the predictive capabilities of established liver or sepsis scores like SOFA, MELD, Child and CLIF-C ACLF. The reliance of the LIVERAID-ICU score on fundamental clinical and laboratory data facilitates its global application in ICUs, enabling immediate application at the bedside for patients with liver cirrhosis during episodes of suspected or confirmed infections.

Reduced Energy Metabolism Impairs T Cell-Dependent B Cell Responses in Patients With Advanced HBV-Related Cirrhosis

Background and Aims

Patients with decompensated HBV-related liver cirrhosis (HBV D-LC) showed compromised immune responses, which manifested as a proneness to develop infections and hyporesponsiveness to vaccines, resulting in accelerated disease progression. The alterations in T cell-dependent B cell responses in this pathophysiological process were not well understood. This study aimed to investigate T cell-dependent B cell responses in this process and discuss the mechanism from the perspective of metabolism.

Methods

Changes in phenotypes and subsets of peripheral B cells between HBV D-LC patients and healthy controls (HCs) were compared by flow cytometry. Isolated B cells were activated by coculture with circulating T follicular (cTfh) cells. After coculture, the frequencies of plasmablasts and plasma cells and immunoglobin levels were analyzed. Oxidative phosphorylation (OXPHOS) and glycolysis were analyzed by a Seahorse analyzer. Mitochondrial function and the AKT/mTOR pathway were analyzed by flow cytometry.

Results

The proliferation and differentiation capacities of B cells after T cell stimulation were impaired in D-LC. Furthermore, we found that B cells from D-LC patients showed reductions in OXPHOS and glycolysis after activation, which may result from reduced glucose uptake, mitochondrial dysfunction and attenuated activation of the AKT/mTOR pathway.

Conclusions

B cells from HBV D-LC patients showed dysfunctional energy metabolism after T cell-dependent activation. Understanding the regulations of B cell metabolic pathway and their changes may provide a new direction to rescue B cell hyporesponsiveness in patients with HBV D-LC, preventing these patients be infected and improving sensitivity to vaccines.

Immunotherapy in hepatocellular carcinoma: the complex interface between inflammation, fibrosis, and the immune response

Hepatocellular carcinoma (HCC) is the third leading cause of cancer deaths worldwide and confers a poor prognosis. Beyond standard systemic therapy with multikinase inhibitors, recent studies demonstrate the potential for robust and durable responses from immune checkpoint inhibition in subsets of HCC patients across disease etiologies. The majority of HCC arises in the context of chronic inflammation and from within a fibrotic liver, with many cases associated with hepatitis virus infections, toxins, and fatty liver disease. Many patients also have concomitant cirrhosis which is associated with both local and systemic immune deficiency. Furthermore, the liver is an immunologic organ in itself, which may enhance or suppress the immune response to cancer arising within it. Here, we explore the immunobiology of the liver from its native state to chronic inflammation, fibrosis, cirrhosis and then to cancer, and summarize how this unique microenvironment may affect the response to immunotherapy.

Immune Dysfunction in Cirrhosis

Cirrhosis due to any etiology disrupts the homeostatic role of liver in the body. Cirrhosis-associated immune dysfunction leads to alterations in both innate and acquired immunity, due to defects in the local immunity of liver as well as in systemic immunity. Cirrhosis-associated immune dysfunction is a dynamic phenomenon, comprised of both increased systemic inflammation and immunodeficiency, and is responsible for 30% mortality. It also plays an important role in acute as well as chronic decompensation. Immune paralysis can accompany it, which is characterized by increase in anti-inflammatory cytokines and suppression of proinflammatory cytokines. There is also presence of increased gut permeability, reduced gut motility and altered gut flora, all of which leads to increased bacterial translocation. This increased bacterial translocation and consequent endotoxemia leads to increased blood stream bacterial infections that cause systemic inflammatory response syndrome, sepsis, multiorgan failure and death. The gut microbiota of cirrhotic patients has more pathogenic microbes than that of non-cirrhotic individuals, and this disturbs the homeostasis and favors gut translocation. Prompt diagnosis and treatment of such infections are necessary for better survival. We have reviewed the various mechanisms of immune dysfunction and its consequences in cirrhosis. Recognizing the exact pathophysiology of immune dysfunction will help treating clinicians in avoiding its complications in their patients and can lead to newer therapeutic interventions and reducing the morbidity and mortality rates.

Immune dysfunction in cirrhosis

Innate and adaptive immune dysfunction, also referred to as cirrhosis-associated immune dysfunction syndrome, is a major component of cirrhosis, and plays a pivotal role in the pathogenesis of both the acute and chronic worsening of liver function. During the evolution of the disease, acute decompensation events associated with organ failure(s), so-called acute-on chronic liver failure, and chronic decompensation with progression of liver fibrosis and also development of disease specific complications, comprise distinct clinical entities with different immunopathology mechanisms. Enhanced bacterial translocation associated with systemic endotoxemia and increased occurrence of systemic bacterial infections have substantial impacts on both clinical situations. Acute and chronic exposure to bacteria and/or their products, however, can result in variable clinical consequences. The immune status of patients is not constant during the illness; consequently, alterations of the balance between pro- and anti-inflammatory processes result in very different dynamic courses. In this review we give a detailed overview of acquired immune dysfunction and its consequences for cirrhosis. We demonstrate the substantial influence of inherited innate immune dysfunction on acute and chronic inflammatory processes in cirrhosis caused by the pre-existing acquired immune dysfunction with limited compensatory mechanisms. Moreover, we highlight the current facts and future perspectives of how the assessment of immune dysfunction can assist clinicians in everyday practical decision-making when establishing treatment and care strategies for the patients with end-stage liver disease. Early and efficient recognition of inappropriate performance of the immune system is essential for overcoming complications, delaying progression and reducing mortality.