Management of hepatorenal syndrome and associated outcomes: a systematic reviews

BACKGROUND

Hepatorenal syndrome (HRS), a multiorgan condition of acute kidney injury, is seen in advanced liver disease. This study aims to evaluate the current treatment for HRS.

METHODS

The authors searched PubMed, Scopus and Google Scholar literature. After quality assessment, 31 studies were included in this review. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses methodology and the population, intervention, comparison and outcome scheme were used. We included human-controlled trials that evaluate the current treatment for HRS. Two authors independently screened articles for inclusion, extracted data and assessed the quality of included studies.

RESULTS

This study investigated the studies conducted on the effects of different treatments on follow-up of HRS patients. We gathered 440 articles, so 31 articles remained in our study. Of which 24 articles were conducted on terlipressin versus placebo or other treatments (midodrine/octreotide, norepinephrine, etc) that showed the higher rate of HRS reversal was detected for terlipressin in 17 studies (10 of them were significant), 2 studies achieved an insignificant lower rate of the model for end-stage liver disease score for terlipressin, 15 studies showed a decreased mortality rate in the terlipressin group (4 of them were significant).

CONCLUSION

This review showed that terlipressin has a significantly higher reversal rate of HRS than the other treatments. Even the results showed that terlipressin is more efficient than midodrine/octreotide and norepinephrine as a previous medication, in reverse HRS, increasing patient survival.

FOXA2 prevents hyperbilirubinaemia in acute liver failure by maintaining apical MRP2 expression

OBJECTIVE

Multidrug resistance protein 2 (MRP2) is a bottleneck in bilirubin excretion. Its loss is sufficient to induce hyperbilirubinaemia, a prevailing characteristic of acute liver failure (ALF) that is closely associated with clinical outcome. This study scrutinises the transcriptional regulation of MRP2 under different pathophysiological conditions.

DESIGN

Hepatic MRP2, farnesoid X receptor (FXR) and Forkhead box A2 (FOXA2) expression and clinicopathologic associations were examined by immunohistochemistry in 14 patients with cirrhosis and 22 patients with ALF. MRP2 regulatory mechanisms were investigated in primary hepatocytes, Fxr -/- mice and lipopolysaccharide (LPS)-treated mice.

RESULTS

Physiologically, homeostatic MRP2 transcription is mediated by the nuclear receptor FXR/retinoid X receptor complex. Fxr-/- mice lack apical MRP2 expression and rapidly progress into hyperbilirubinaemia. In patients with ALF, hepatic FXR expression is undetectable, however, patients without infection maintain apical MRP2 expression and do not suffer from hyperbilirubinaemia. These patients express FOXA2 in hepatocytes. FOXA2 upregulates MRP2 transcription through binding to its promoter. Physiologically, nuclear FOXA2 translocation is inhibited by insulin. In ALF, high levels of glucagon and tumour necrosis factor α induce FOXA2 expression and nuclear translocation in hepatocytes. Impressively, ALF patients with sepsis express low levels of FOXA2, lose MRP2 expression and develop severe hyperbilirubinaemia. In this case, LPS inhibits FXR expression, induces FOXA2 nuclear exclusion and thus abrogates the compensatory MRP2 upregulation. In both Fxr -/- and LPS-treated mice, ectopic FOXA2 expression restored apical MRP2 expression and normalised serum bilirubin levels.

CONCLUSION

FOXA2 replaces FXR to maintain MRP2 expression in ALF without sepsis. Ectopic FOXA2 expression to maintain MRP2 represents a potential strategy to prevent hyperbilirubinaemia in septic ALF.

MerTK expressing hepatic macrophages promote the resolution of inflammation in acute liver failure

OBJECTIVE

Acute liver failure (ALF) is characterised by overwhelming hepatocyte death and liver inflammation with massive infiltration of myeloid cells in necrotic areas. The mechanisms underlying resolution of acute hepatic inflammation are largely unknown. Here, we aimed to investigate the impact of Mer tyrosine kinase (MerTK) during ALF and also examine how the microenvironmental mediator, secretory leucocyte protease inhibitor (SLPI), governs this response.

DESIGN

Flow cytometry, immunohistochemistry, confocal imaging and gene expression analyses determined the phenotype, functional/transcriptomic profile and tissue topography of MerTK+ monocytes/macrophages in ALF, healthy and disease controls. The temporal evolution of macrophage MerTK expression and its impact on resolution was examined in APAP-induced acute liver injury using wild-type (WT) and Mer-deficient (Mer^-/-) mice. SLPI effects on hepatic myeloid cells were determined in vitro and in vivo using APAP-treated WT mice.

RESULTS

We demonstrate a significant expansion of resolution-like MerTK+HLA-DR^high cells in circulatory and tissue compartments of patients with ALF. Compared with WT mice which show an increase of MerTK+MHCII^high macrophages during the resolution phase in ALF, APAP-treated Mer^-/- mice exhibit persistent liver injury and inflammation, characterised by a decreased proportion of resident Kupffer cells and increased number of neutrophils. Both in vitro and in APAP-treated mice, SLPI reprogrammes myeloid cells towards resolution responses through induction of a MerTK+HLA-DR^high phenotype which promotes neutrophil apoptosis and their subsequent clearance.

CONCLUSIONS

We identify a hepatoprotective, MerTK+, macrophage phenotype that evolves during the resolution phase following ALF and represents a novel immunotherapeutic target to promote resolution responses following acute liver injury.

MiR-19a Affects Hepatocyte Autophagy via Regulating lncRNA NBR2 and AMPK/PPARα in D-GalN/Lipopolysaccharide-Stimulated Hepatocytes

This study aims to evaluate the potential involvement and regulatory mechanism of miR-19a in hepatocytes autophagy of acute liver failure (ALF). The in vitro hepatocytes injury model of primary hepatocyte and hepatocytes line HL-7702 was established by D-galactosamine (D-GalN) and lipopolysaccharide (LPS) co-treatment. Relative expression level of miR-19a and NBR2 was determined by qRT-PCR. Protein expression of AMPK/PPARα and autophagy-related gene was determined by Western blot. In hepatic tissue of 20 ALF patients and D-GalN/LPS-stimulated hepatocytes, miR-19a was upregulated and NBR2 was downregulated. D-GalN/LPS stimulation caused the inactivation of AMPK/PPARα signaling and the decrease of autophagy-related LC3-II/LC3-I ratio and beclin-1 expression in hepatocytes. The expression of both AMPK/PPARα and NBR2 were negatively controlled by miR-19a overexpression or knockdown. Moreover, both NBR2 and PPARα were targeted regulated by miR-19a according to luciferase reporter assay. In D-GalN/LPS-stimulated hepatocytes, AMPK activation promoted PPARα expression. AMPK inactivation inhibited the pro-autophagy effect of miR-19a and caused the decrease of LC3-II/LC3-I ratio and beclin-1 expression. PPARα activation abrogated the anti-autophagy effect of miR-19a mimic and caused the increase of LC3-II/LC3-I ratio and beclin-1 expression. NBR2 knockdown reversed the anti-autophagy impact of miR-19a inhibitor and caused the decrease of LC3-II/LC3-I ratio and beclin-1 expression. In summary, our data suggested that miR-19a negatively controlled the autophagy of hepatocytes attenuated in D-GalN/LPS-stimulated hepatocytes via regulating NBR2 and AMPK/PPARα signaling. J. Cell. Biochem. 119: 358-365, 2018. © 2017 Wiley Periodicals, Inc.

PGAM5-mediated programmed necrosis of hepatocytes drives acute liver injury

OBJECTIVES

Autoimmune hepatitis (AIH) is a severe necroinflammatory liver disease associated with significant mortality. Although loss of hepatocytes is generally recognised as a key trigger of liver inflammation and liver failure, the regulation of hepatic cell death causing AIH remains poorly understood. The aim of this study was to identify molecular mechanisms that drive hepatocyte cell death in the pathogenesis of acute liver injury.

DESIGN

Acute liver injury was modelled in mice by intravenous administration of concanavalin A (ConA). Liver injury was demonstrated by serum transaminases and histological assessment of liver sections. PGAM5-deficient mice (PGAM5-/-) were used to determine its role in experimental hepatitis. Mdivi-1 was used as an inhibitor of dynamin-related protein 1 (Drp1)-mediated mitochondrial fission. Mitochondrial fission and the expression of PGAM5 were compared between liver biopsies derived from patients with AIH and control patients.

RESULTS

PGAM5 was highly expressed in hepatocytes of patients with AIH and in mice with ConA-induced experimental hepatitis. Deficiency of PGAM5 protected mice from ConA-induced hepatocellular death and liver injury. PGAM5 regulated ConA-induced mitochondrial fission in hepatocytes. Administration of the Drp1-inhibitor Mdivi-1 blocked mitochondrial fission, diminished hepatocyte cell death and attenuated liver tissue damage induced by ConA.

CONCLUSIONS

Our data demonstrate for the first time that PGAM5 plays an indispensable role in the pathogenesis of ConA-induced liver injury. Downstream of PGAM5, Drp1-mediated mitochondrial fission is an obligatory step that drives the execution of hepatic necrosis and tissue damage. Our data highlight the PGAM5-Drp1 axis as a potential therapeutic target for acute immune-mediated liver injury.

Acute kidney injury and acute-on-chronic liver failure classifications in prognosis assessment of patients with acute decompensation of cirrhosis

OBJECTIVE

Prognostic stratification of patients with cirrhosis is common clinical practice. This study compares the prognostic accuracy (28-day and 90-day transplant-free mortality) of the acute-on-chronic liver failure (ACLF) classification (no ACLF, ACLF grades 1, 2 and 3) with that of acute kidney injury (AKI) classification (no AKI, AKI stages 1, 2 and 3).

DESIGN

The study was performed in 510 patients with an acute decompensation of cirrhosis previously included in the European Association for the Study of the Liver-Chronic Liver Failure consortium CANONIC study. ACLF was evaluated at enrollment and 48 h after enrollment, and AKI was evaluated at 48 h according to Acute Kidney Injury Network criteria.

RESULTS

240 patients (47.1%) met the criteria of ACLF at enrollment, while 98 patients (19.2%) developed AKI. The presence of ACLF and AKI was strongly associated with mortality. 28-day transplant-free mortality and 90-day transplant-free mortality of patients with ACLF (32% and 49.8%, respectively) were significantly higher with respect to those of patients without ACLF (6.2% and 16.4%, respectively; both p<0.001). Corresponding values in patients with and without AKI were 46% and 59%, and 12% and 25.6%, respectively (p<0.0001 for both). ACLF classification was more accurate than AKI classification in predicting 90-day mortality (area under the receiving operating characteristic curve=0.72 vs 0.62; p<0.0001) in the whole series of patients. Moreover, assessment of ACLF classification at 48 h had significantly better prognostic accuracy compared with that of both AKI classification and ACLF classification at enrollment.

CONCLUSIONS

ACLF stratification is more accurate than AKI stratification in the prediction of short-term mortality in patients with acute decompensation of cirrhosis.

Hepatic decompensation in the absence of obvious precipitants: the potential role of cytomegalovirus infection/reactivation

Details of two patients with alcohol-related and mixed aetiology cirrhosis who developed acute-on-chronic liver failure/hepatic decompensation with no obvious precipitants are reported. Cytomegalovirus (CMV) infection or reactivation was diagnosed in both, and required treatment with ganciclovir in one. Both returned to baseline hepatic function and remain well. Physicians should be alert to the possibility that CMV might cause or contribute to hepatic decompensation in patients with cirrhosis, even if they are not severely immunocompromised, and especially if they are alcohol misusers.

Circulating histones exacerbate inflammation in mice with acute liver failure

Circulating histones are a newly recognized mediator implicated in various inflammatory diseases. It is likely that the release of histones, from dying hepatocytes or inflammatory leukocytes, into the circulation initiates and amplifies inflammation during the course of acute liver failure (ALF). In this study, we investigated a putative pathogenic role of circulating histones in a murine model of ALF induced by D-galactosamine (GalN) plus lipopolysaccharide (LPS). Hepatic function and histological indexes, myeloperoxidase (MPO) activity, hepatocyte apoptosis and the levels of circulating histone were measured in GalN/LPS-treated mice. GalN/LPS caused severe liver damage and a notable increase in plasma concentration of circulating histones. To further assess the role of circulating histones in our model, we administered exogenous histones and anti-histone H4 antibody. Notably, exogenous histones aggravated GalN/LPS-induced hepatotoxicity, whereas anti-histone antibody significantly protected mice. Circulating histones may serve as both a functional marker of ALF activity and as an inflammatory mediator contributing to the progression of ALF. Blockade of circulating histones shows potent protective effects, suggesting a potential therapeutic strategy for ALF.