Bacterial translocation and its consequences in patients with cirrhosis

Infection et rupture de varice œsophagienne au cours de la cirrhose

Endotoxemia and bacterial infection are frequent in patients with cirrhosis. They alter systemic and splanchnic hemodynamics, worsen coagulation disorders, impair liver function and thus may induce variceal bleeding. In variceal bleeding, bacterial infection favours failure to control bleeding, early rebleeding, and death. In patients with cirrhosis and variceal bleeding, antibiotic-prophylaxis decreases bacterial infection and the incidence of early rebleeding, and, more important, significantly decreases the death rate in these patients.

Clinical significance of Toll-like receptor 4 and 2 expression on the surface of peripheral blood mononuclear cells in patients with liver cirrhosis

AIM: To explore the correlation of Toll-like receptor 4, Toll-like receptors 2 expression on the surface of peripheral blood mononuclear cells with bacterial infection in patients with liver cirrhosis, and observe the effect of antibiotics on PBMC expression of TLR4 and TLR2 in cirrhosis.

METHODS: Blood cells from a total of 42 patients (30 with ascites, 12 without ascites) with liver cirrhosis and 15 normal controls were stained with fluorescent labeling anti-TLR2/anti-TLR4/anti-CD14 monoclonal antibodies. Samples were collected and analyzed for three-color immunofluorescence by flow cytometry.

RESULTS: The expression of TLR4 and TLR2 were significantly higher in patients with ascites than those in the controls (TLR4: 22.28 ± 0.80 vs 14.45 ± 3.23, P < 0.05; TLR2: 47.65 ± 0.75 vs 24.40 ± 2.77, P < 0.05), and marked difference also existed before and after treatment (TLR4: 28.58 ± 0.79 vs 12.37 ± 0.35, P < 0.05; TLR2: 47.79 ± 0.76 vs 17.22 ± 2.48, P < 0.05). TLR4 and TLR2 expression were notably increased in patients with ascites as compared with those in ones without ascites (TLR2: 25.37 ± 1.62; TLR4: 14.81 ± 0.29) (P < 0.05), and they were not significantly different between patients without ascites and normal controls (P > 0.05).

CONCLUSION: PBMC expression of TLR4 and TLR2 are up-regulated in patients with liver cirrhosis, and they can be down-regulated by antibiotics treatment.

Upregulation of TNF-alpha production signaling pathways in monocytes from patients with advanced cirrhosis: possible role of Akt and IRAK-M

BACKGROUND/AIMS

In cirrhosis, tumor necrosis factor (TNF)-alpha overproduction is involved in both the systemic complications and progression of liver injury. Since monocytes from patients with advanced cirrhosis have an increase in lipopolysaccharide (LPS)-induced TNF-alpha production, we hypothesized that an upregulation of TNF-alpha production pathways and/or alteration of constitutive and inducible suppressor of TNF-alpha hyperproduction (protein kinase B (Akt) and interleukin-1 receptor-associated kinase (IRAK)-M, respectively) should be found in monocytes of these patients. Thus, we investigated ex vivo the signaling pathways of TNF-alpha production before and after LPS incubation in monocytes from noninfected Child-Pugh C patients with advanced cirrhosis and healthy subjects.

METHODS

TNF-alpha production, expressions of intracellular TNF-alpha, toll-like receptor-4 (TLR4), IkappaB-alpha, IRAK-1, IRAK-M, mitogen-activated protein (MAP) kinases and Akt activity were measured in monocytes.

RESULTS

Cirrhotic monocytes without LPS have less TLR4 expression, less IkappaB-alpha protein levels, more TNF-alpha expression, higher MAP kinase activities and decreased Akt activity than control monocytes. In cirrhotic monocytes, LPS-induced TNF-alpha hyperproduction and signaling upregulation were associated with a lack of IRAK-M induction.

CONCLUSIONS

Upregulated signaling pathways of the TNF-alpha production, decreased Akt activity and a lack of IRAK-M induction may be involved in the process of cirrhotic monocyte sensitization to produce TNF-alpha.

Association between portal endotoxemia and Child-Pugh classification in complex pathogens-induced hepatic cirrhosis in rats

AIM: To evaluate the association between the Child-Pugh classification and portal endotoxe-mia during the course of rat liver cirrhosis induced by carbon tetrachloride (CCl₄) plus ethanol and cholesterol.

METHODS: Liver cirrhosis model was induced in 20 Wistar rats using CCl₄ plus ethanol and cholesterol, while 6 rats were treated as controls. At 6 and 10 wk, serum samples were collected from portal vein for the detection of prothrombin time, albumin, bilirubin and endotoxin level, and the ascites and brain wave were also tested. The liver function was evaluated by Child-Pugh scoring system and the relationship between Child-Pugh classification and portal endotoxemia was assessed.

RESULTS: Spearman rank correlation analysis showed that Child-Pugh grading was correlated with albumin level and prothrombin time (r = -0.695, P < 0.05; r = 0.649, P < 0.05), but not with bilirubin level (P > 0.05). The level of endotoxin in portal vein was elevated with prolonging of cirrhosis time, and it was significantly higher at 6 or 10 wk than that in the controls (1983.7 ± 586.4, 2600.7 ± 343.8 mEU/L vs 925.1 ± 527.7 mEU/L, both P < 0.01). Endotoxin level was correlated with cirrhosis time (r = 0.624, P < 0.01) and Child-Pugh classification (r = 0.680, P < 0.01).

CONCLUSION: Portal endotoxemia is significantly correlated with Child-Pugh classification, indicating that intestinal endotoxemia plays an important role during the course of complex pathogens-induced cirrhosis in rats.

Clinical significance of serum procalcitonin levels in patients with acute or chronic liver disease

OBJECTIVE

To evaluate the diagnostic value of serum procalcitonin levels in patients with acute or chronic liver disease, with or without bacterial infections and to correlate the results with the clinical outcome and the laboratory findings for these patients.

METHODS

One hundred and six consecutive hospitalized patients with liver disease were evaluated for procalcitonin levels on admission. Fifteen of them (14.2%) had acute alcoholic hepatitis on cirrhotic background (group A), 20 (18.9%) had alcoholic cirrhosis without hepatitis and/or bacterial infection (group B), 16 (15.1%) had decompensated cirrhosis with proved bacterial infection (group C), 42 (39.6%) had uncomplicated viral hepatitis-related cirrhosis (group D) and 13 (12.3%) had acute icteric viral hepatitis (group E). Serum procalcitonin levels were measured using an immunoluminometric assay. Statistical analysis was based on Student's t-test and the non-parametric Kruskall-Wallis test (P<0.05).

RESULTS

Serum procalcitonin levels were significantly higher in cirrhotic patients with bacterial infection (9.80+/-16.80 ng/ml) than in those without bacterial infection (0.21+/-0.13 ng/ml, P=0.001), whereas they were within normal range (<0.5 ng/ml) in all patients with uncomplicated cirrhosis, irrespective of the cause of cirrhosis. Seven of 15 group A patients (46.2%) and 4/13 group E patients (30.8%), all of them cirrhotics, had procalcitonin levels higher than 0.5 ng/ml on admission, without established bacterial infection.

CONCLUSION

Serum procalcitonin levels remain below the threshold of 0.5 ng/ml in all patients with uncomplicated cirrhosis, irrespective of the cause of the disease, while they are significantly elevated when bacterial infection complicates the course of the disease. A significant proportion of patients with acute alcoholic hepatitis on a cirrhotic background as well as of patients with acute on chronic viral hepatitis, without bacterial infection, exhibit serum procalcitonin levels above 0.5 ng/ml, suggesting that this cut-off value is probably not enough to discriminate between patients with or without bacterial infection within these subgroups of patients with liver disease.

Similarities and differences in outcomes of cirrhosis due to nonalcoholic steatohepatitis and hepatitis C

The objective of this study was to prospectively define outcomes of cirrhosis due to nonalcoholic steatohepatitis (NASH) and compare them with those associated with hepatitis C virus (HCV) infection. We compared 152 patients with cirrhosis due to NASH with 150 matched patients with cirrhosis due to HCV. Over 10 years, 29/152 patients with cirrhosis due to NASH died compared with 44/150 patients with HCV (P < .04). This was mainly due to the lower mortality rate in patients with Child class A cirrhosis due to NASH versus HCV (3/74 vs. 15/75; P < .004). There were no significant across-group differences in mortality in patients with Child class B or C cirrhosis. Sepsis was the most common cause of death in both groups; patients with NASH had a higher cardiac mortality (8/152 vs. 1/150; P < .03). Patients with Child class A cirrhosis due to NASH also had a significantly lower risk of decompensation, defined by a 2-point increase in Child-Turcotte-Pugh score (P < .007). Cirrhosis due to NASH was associated with a lower rate of development of ascites (14/101 vs. 40/97 patients at risk; P < .006). NASH also had a significantly lower risk of development of hepatocellular carcinoma (10/149 vs. 25/147 patients at risk; P < .01). In conclusion, compensated cirrhosis due to NASH is associated with a lower mortality rate compared with that due to HCV. It is also associated with a lower rate of development of ascites, hyperbilirubinemia, and hepatocellular carcinoma. However, cardiovascular mortality is greater in patients with NASH.

Intestinal permeability in cirrhotic patients with and without ascites

OBJECTIVE

It has been suggested that increased intestinal permeability plays a pathogenic role in bacterial infections, such as spontaneous bacterial peritonitis, in patients with liver cirrhosis. The aim of this study was to assess whether intestinal permeability is altered in cirrhotic patients with and without ascites.

MATERIAL AND METHODS

Intestinal permeability was assessed by a (51)Cr-EDTA permeability test in 20 cirrhotic patients (10 with and 10 without ascites) along with 20 age- and gender-matched healthy controls. In six patients with ascites, the test was performed before and after therapeutic paracentesis.

RESULTS

The median (IQR) 24-h urinary excretion of (51)Cr-EDTA was higher in patients with cirrhosis (1.94% (1.21-2.70%)) compared with that in controls (1.40% (1.09-1.99%); p<0.05). Patients with (2.05% (1.50-3.46%); p<0.05) but not those without ascites (1.94% (1.13-2.53%); p>0.1) had significantly higher excretion values compared with those of controls. Only one patient without ascites and a total of four patients with ascites had increased intestinal permeability ((51)Cr-EDTA excretion > 95% confidence than that of controls; p>0.1). Paracentesis did not affect urinary (51)Cr-EDTA excretion significantly (1.69% (1.16-2.86%) versus 1.30% (1.08-1.79%) before and after, respectively; p>0.1). No significant correlation was found between clinical severity scores for liver disease and intestinal permeability.

CONCLUSIONS

Only a small proportion of patients with liver cirrhosis have increased intestinal permeability and it is unlikely that this plays any major role in predisposing these patients to infections.