Toll-like receptor 4 polymorphisms and bacterial infections in patients with cirrhosis and ascites

Single Nucleotide Polymorphisms of Toll-like Receptor 4 in Hepatocellular Carcinoma-A Single-Center Study

Hepatocellular carcinoma (HCC) is the most common primary liver tumor leading to significant morbidity and mortality; its exact genetic background is largely unrecognized. Toll-like receptor-4 (TLR4) reacts with lipopolysaccharides, molecules found in the outer membrane of Gram-negative bacteria. In damaged liver, TLR4 expression is upregulated, leading to hepatic inflammation and injury. We tried to investigate the role of the two most common single-nucleotide polymorphisms (SNPs) of TLR4 in HCC-genesis. Aged > 18 years old, cirrhotic patients were included in this study. Exclusion criteria were non-HCC tumors and HIV co-infection. TLR4 SNPs association with HCC occurrence was the primary endpoint, and associations with all-cause and liver-related mortality, as well as time durations between diagnosis of cirrhosis and HCC development or death and diagnosis of HCC and death were secondary endpoints. A total of 52 out of 260 included patients had or developed HCC. TLR4 SNPs showed no correlation with primary or secondary endpoints, except for the shorter duration between HCC development and death in patients with TLR4 mutations. Overall, TLR4 SNPs showed no correlation with carcinogenesis or deaths in patients with liver cirrhosis; patients with TLR4 SNPs that developed HCC had lower survival rates, a finding that should be further evaluated.

Characteristics of pathogenic bacteria in intra-abdominal infection and risk factors for septic shock in patients with liver cirrhosis

OBJECTIVE

To explore the characteristics of pathogenic bacteria in intra-abdominal infection and the risk factors for septic shock in patients with liver cirrhosis.

METHODS

This retrospective study analyzed the clinical data of patients with cirrhosis admitted to the Department of Infectious Diseases of the 910^th Hospital of Chinese People's Liberation Army, who were divided into an intra-abdominal infection group (n=145) and non-infection group (n=100). We analyzed the risk factors for intra-abdominal infection in patients with liver cirrhosis, and further conducted bacterial culture for patients with intra-abdominal infection to investigate the distribution of pathogenic bacteria and analyzed the risk factors for septic shock.

RESULTS

Multivariate regression analysis found that age (P=0.005), length of hospital stay (P=0.024), invasive operation (P=0.002), and hypoproteinemia (P=0.026) were risk factors for intra-abdominal infection in patients with cirrhosis. 65 of the 145 patients with intra-abdominal infection were tested to be pathogen-positive, with a positivity rate of 44.83%. A total of 118 strains were isolated from the samples of 65 patients with positive test results. Among the 118 strains, 74 of them were gram-negative bacteria (62.71%), 41 were gram-positive bacteria (34.75%), and 3 were fungus (2.54%). Multivariate regression analysis found that age (P=0.003), length of stay (P=0.001), invasive operations (P=0.024) and hypoproteinemia (P=0.001) were all risk factors for septic shock in patients with liver cirrhosis combined with intra-abdominal infection.

CONCLUSION

Age, length of hospital stay, invasive operation, and hypoproteinemia are risk factors for intra-abdominal infection and septic shock in patients with cirrhosis, and gram-negative bacteria are the main pathogens in associated intra-abdominal infection.

The fibrogenic process and the unleashing of acute-on-chronic liver failure

Acute-on-chronic liver failure (ACLF) is a life-threatening condition characterized by a rapid deterioration of previously well-compensated chronic liver diseases. One of the main obstacles in ACLF is the lack of knowledge of the pathogenesis and specific broad-spectrum treatments. An excessive systemic inflammatory response has been proposed to explain the pathogenesis of ACLF; this hypothesis involves stellate cells, which are implicated in many liver homeostatic functions that include vitamin A storage, regulation of sinusoidal blood flow, local inflammation, maintenance of the hepatocyte phenotype and extracellular matrix remodeling. However, when there is damage to the liver, these cells are the main target of the inflammatory stimulus, as a result, the secretion of the extracellular matrix is altered. Activated hepatic stellate cells raise the survival of neutrophils by the stimulation of granulocytes colonies and macrophages, which exacerbates liver inflammation and promotes damage to hepatocytes. Elevation of pathogen-associated molecular patterns is related to liver damage by different pathophysiological mechanisms of decompensation, showing ballooning degeneration and cell death with a predominance of cholestatic infection. Moreover, patients with ACLF present a marked elevation of C-reactive protein together with an elevation of the leukocyte count. Chronic liver disease is a complex pathological state with a heterogeneous pathophysiology in which genetic factors of the host and external triggers interact and culminate in hepatic insufficiency. The better understanding of such interactions should lead to a better comprehension of the disease and to the discovery of new treatment targets that will make acute decompensations preventable and even decrease mortality.

Causes and Consequences of Innate Immune Dysfunction in Cirrhosis

Liver cirrhosis is an increasing health burden and public health concern. Regardless of etiology, patients with cirrhosis are at risk of a range of life-threatening complications, including the development of infections, which are associated with high morbidity and mortality and frequent hospital admissions. The term Cirrhosis-Associated Immune Dysfunction (CAID) refers to a dynamic spectrum of immunological perturbations that develop in patients with cirrhosis, which are intimately linked to the underlying liver disease, and negatively correlated with prognosis. At the two extremes of the CAID spectrum are systemic inflammation, which can exacerbate clinical manifestations of cirrhosis such as hemodynamic derangement and kidney injury; and immunodeficiency, which contributes to the high rate of infection in patients with decompensated cirrhosis. Innate immune cells, in particular monocytes/macrophages and neutrophils, are pivotal effector and target cells in CAID. This review focuses on the pathophysiological mechanisms leading to impaired innate immune function in cirrhosis. Knowledge of the phenotypic manifestation and pathophysiological mechanisms of cirrhosis associated immunosuppression may lead to immune targeted therapies to reduce susceptibility to infection in patients with cirrhosis, and better biomarkers for risk stratification, and assessment of efficacy of novel immunotherapies.