Background and Aims
In nonalcoholic fatty liver disease (NAFLD), fibrosis is the most important factor contributing to NAFLD‐associated morbidity and mortality. Prevention of progression and reduction in fibrosis are the main aims of treatment. Even in early stages of NAFLD, hepatic and systemic hyperammonemia is evident. This is due to reduced urea synthesis; and as ammonia is known to activate hepatic stellate cells, we hypothesized that ammonia may be involved in the progression of fibrosis in NAFLD.
Approach and Results
In a high‐fat, high‐cholesterol diet–induced rodent model of NAFLD, we observed a progressive stepwise reduction in the expression and activity of urea cycle enzymes resulting in hyperammonemia, evidence of hepatic stellate cell activation, and progressive fibrosis. In primary, cultured hepatocytes and precision‐cut liver slices we demonstrated increased gene expression of profibrogenic markers after lipid and/or ammonia exposure. Lowering of ammonia with the ammonia scavenger ornithine phenylacetate prevented hepatocyte cell death and significantly reduced the development of fibrosis both in vitro in the liver slices and in vivo in a rodent model. The prevention of fibrosis in the rodent model was associated with restoration of urea cycle enzyme activity and function, reduced hepatic ammonia, and markers of inflammation.
Conclusions
The results of this study suggest that hepatic steatosis results in hyperammonemia, which is associated with progression of hepatic fibrosis. Reduction of ammonia levels prevented progression of fibrosis, providing a potential treatment for NAFLD.
Background: Heart rate variability (HRV) is reduced in cirrhosis and in conditions of systemic inflammation. Whether HRV is associated with cirrhosis decompensation and development of acute-on-chronic liver failure (ACLF) is unknown.Aims: To (a) validate wireless remote HRV monitoring in cirrhosis decompensation;(b) determine if severely reduced HRV is a surrogate for inflammation and progression of cirrhosis decompensation; (c) assess if measuring HRV determines prognosis in cirrhosis decompensation.
Methods:One hundred and eleven patients at risk of cirrhosis decompensation at two clinical sites were monitored for HRV. Standard deviation of all normal beatbeat intervals (SDNN) reflecting HRV was assessed using remote monitoring (Isansys Lifetouch) and/or Holter ECG recording. Clinical outcomes and major prognostic scores were recorded during 90-day follow-up.Results: Reduced HRV denoted by lower baseline SDNN, correlated with severity of decompensation (median 14 (IQR 11-23) vs 33 (25-42); P < 0.001, decompensated patients vs stable outpatient cirrhosis). Furthermore, SDNN was significantly lower in patients developing ACLF compared to those with only decompensation (median 10 (IQR9-12) vs 16 (11-24); P = 0.02), and correlated inversely with MELD and Child-Pugh scores, and C-reactive protein (all P < 0.0001) and white cell count (P < 0.001).SDNN predicted disease progression on repeat measures and appeared an independent predictor of 90-day mortality (12 patients). An SDNN cut-off of 13.25 ms had a 98% negative predictive value.
| 569JANSEN Et Al.
Background: In cirrhosis, a pathological gut microbiome has been linked with immune dysfunction. A pilot study of probiotic Lactobacillus casei Shirota (LcS) in alcoholic cirrhosis demonstrated significant improvement in neutrophil function. This study aimed to evaluate the efficacy of LcS on neutrophil function and significant infection rates in patients with cirrhosis. Methods: 92 cirrhotic patients (Child–Pugh score ≤10) were randomized to receive LcS or placebo, three times daily for six months. Primary end-points were incidence of significant infection and neutrophil function. Secondary end-points were cytokine profile, endotoxin, bacterial DNA positivity, intestinal permeability and quality of life. Results: Rates of infection, decompensation or neutrophil function did not differ between placebo and probiotic groups. LcS significantly reduced plasma monocyte chemotactic protein-1 and, on subgroup analysis, plasma interleukin-1β (alcoholic cirrhosis), interleukin-17a and macrophage inflammatory protein-1β (non-alcoholic cirrhosis), compared with placebo. No significant differences in intestinal permeability, bacterial translocation or metabolomic profile were observed. Conclusion: LcS supplementation in patients with early cirrhosis is safe. Although no significant infections were observed in either group, LcS improved cytokine profile towards an anti-inflammatory phenotype, an effect which appears to be independent of bacterial translocation.
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