Surgical Treatment of Persistent Pseudomonas aeruginosa Bacteraemia After n-Butyl-2-cyanoacrylate for Gastric Bleeding Varices

n-Butyl-2-cyanoacrylate (NCBA) is an effective therapeutic option for bleeding gastric varices but can sometimes be associated with adverse effects. Persistent bacteraemia is an unusual complication with a high mortality rate. We report the case of a 34-year-old man with history of cirrhosis due to Wilson's disease and severe portal hypertension who was hospitalized as a result of upper gastrointestinal bleeding secondary to fundic varices that were treated with NCBA. Eight weeks after the bleeding episode he was readmitted with a 14-day history of fever and chills. Pseudomonas aeruginosa was isolated from blood cultures. He presented with persistent P. aeruginosa bacteraemia despite correct antibiotic treatment. A PET-CT scan was performed to rule out infection source, and inflammatory changes at the NCBA site plug were found. A presumptive diagnosis of NCBA plug infection was considered. The case was evaluated by multidisciplinary board and indicated liver transplantation as treatment. However, the patient's bacteraemia persisted and therefore a vertical gastrectomy to remove the NCBA plug was performed. P. aeruginosa was also isolated from the plug. The patient was discharged with ceftazidime plus ciprofloxacin to complete 6 weeks after surgery and he remained asymptomatic. Any foreign material such as NCBA is susceptible to being infected and should be considered in patients with persistent breakthrough bloodstream infections. The individualized treatment is recommended in this complex scenario.

Recompensation in cirrhosis: unravelling the evolving natural history of nonalcoholic fatty liver disease

Recompensation has gained increasing attention in the field of cirrhosis, particularly in chronic liver disease with a definite aetiology. The current global prevalence of obesity and nonalcoholic fatty liver disease (NAFLD) is increasing, but there is currently a lack of a clear definition for recompensation in NAFLD-related cirrhosis. Here, we provide an up-to-date perspective on the natural history of NAFLD, emphasizing the reversible nature of the disease, summarizing possible mechanisms underlying recompensation in NAFLD, discussing challenges that need to be addressed and outlining future research directions in the field. Recompensation is a promising goal in patients with NAFLD-related cirrhosis, and further studies are needed to explore its underlying mechanisms and uncover its clinical features.

Immune responses and clinical outcomes after COVID-19 vaccination in patients with liver disease and liver transplant recipients

BACKGROUND & AIMS

Comparative assessments of immunogenicity following different COVID-19 vaccines in patients with distinct liver diseases are lacking. SARS-CoV-2-specific T-cell and antibody responses were evaluated longitudinally after one to three vaccine doses, with long-term follow-up for COVID-19-related clinical outcomes.

METHODS

A total of 849 participants (355 with cirrhosis, 74 with autoimmune hepatitis [AIH], 36 with vascular liver disease [VLD], 257 liver transplant recipients [LTRs] and 127 healthy controls [HCs]) were recruited from four countries. Standardised immune assays were performed pre and post three vaccine doses (V1-3).

RESULTS

In the total cohort, there were incremental increases in antibody titres after each vaccine dose (p <0.0001). Factors associated with reduced antibody responses were age and LT, whereas heterologous vaccination, prior COVID-19 and mRNA platforms were associated with greater responses. Although antibody titres decreased between post-V2 and pre-V3 (p = 0.012), patients with AIH, VLD, and cirrhosis had equivalent antibody responses to HCs post-V3. LTRs had lower and more heterogenous antibody titres than other groups, including post-V3 where 9% had no detectable antibodies; this was heavily influenced by intensity of immunosuppression. Vaccination increased T-cell IFNγ responses in all groups except LTRs. Patients with liver disease had lower functional antibody responses against nine Omicron subvariants and reduced T-cell responses to Omicron BA.1-specific peptides compared to wild-type. 122 cases of breakthrough COVID-19 were reported of which 5/122 (4%) were severe. Of the severe cases, 4/5 (80%) occurred in LTRs and 2/5 (40%) had no serological response post-V2.

CONCLUSION

After three COVID-19 vaccines, patients with liver disease generally develop robust antibody and T-cell responses to vaccination and have mild COVID-19. However, LTRs have sustained no/low antibody titres and appear most vulnerable to severe disease.

IMPACT AND IMPLICATIONS

Standardised assessments of the immune response to different COVID-19 vaccines in patients with liver disease are lacking. We performed antibody and T-cell assays at multiple timepoints following up to three vaccine doses in a large cohort of patients with a range of liver conditions. Overall, the three most widely available vaccine platforms were immunogenic and appeared to protect against severe breakthrough COVID-19. This will provide reassurance to patients with chronic liver disease who were deemed at high risk of severe COVID-19 during the pre-vaccination era, however, liver transplant recipients had the lowest antibody titres and remained vulnerable to severe breakthrough infection. We also characterise the immune response to multiple SARS-CoV-2 variants and describe the interaction between disease type, severity, and vaccine platform. These insights may prove useful in the event of future viral infections which also require rapid vaccine development and delivery to patients with liver disease.

The genetics of portal hypertension: Recent developments and the road ahead

Portal hypertension (PH), defined as a pathological increase in the portal vein pressure, has different aetiologies and causes. Intrahepatic PH is mostly secondary to the presence of underlying liver disease leading to cirrhosis, characterized by parenchymal changes with deregulated accumulation of extracellular matrix and vascular abnormalities; liver sinusoidal endothelial cells and hepatic stellate cells are key players in PH progression, able to influence each other. However, PH may also develop independently of parenchymal damage, as occur in portosinusoidal vascular disorder (PSVD), a group of clinical and histological entities characterized by portal vasculature dysfunctions. In this particular group of disorders, the pathophysiology of PH is still poorly understood. In the last years, several genetic studies, based on genome-wide association studies or whole-exome sequencing analysis, have highlighted the importance of genetic heritability in PH pathogenesis, both in cirrhotic and non-cirrhotic cases. The common PNPLA3 p.I148M variant, one of the main determinants of the susceptibility to steatotic liver disease, has also been associated with decompensation in patients with PH. Genetic variations at loci influencing coagulation, mainly the ABO locus, may directly contribute to the pathogenesis of PH. Rare genetic variants have been associated with familiar cases of progressive PSVD. In this review, we summarize the recent knowledges on genetic variants predisposing to PH development, contributing to better understand the role of genetic factors in PH pathogenesis.

TIPS prevents further decompensation and improves survival in patients with cirrhosis and portal hypertension in an individual patient data meta-analysis

BACKGROUND & AIMS

Further decompensation represents a prognostic stage of cirrhosis associated with higher mortality compared with first decompensation. A transjugular intrahepatic portosystemic shunt (TIPS) is indicated to prevent variceal rebleeding and for refractory ascites, but its overall efficacy to prevent further decompensations is unknown. This study assessed the incidence of further decompensation and mortality after TIPS vs. standard of care (SOC).

METHODS

Controlled studies assessing covered TIPS compared with SOC for the indication of refractory ascites and prevention of variceal rebleeding published from 2004 to 2020 were considered. We collected individual patient data (IPD) to perform an IPD meta-analysis and to compare the treatment effect in a propensity score (PS)-matched population. Primary outcome was the incidence of further decompensation and the secondary outcome was overall survival.

RESULTS

In total, 3,949 individual patient data sets were extracted from 12 controlled studies and, after PS matching, 2,338 patients with similar characteristics (SOC = 1,749; TIPS = 589) were analysed. The 2-year cumulative incidence function of further decompensation in the PS-matched population was 0.48 (95% CI 0.43-0.52) in the TIPS group vs. 0.63 (95% CI 0.61-0.65) in the SOC group (stratified Gray's test, p <0.0001), considering mortality and liver transplantation as competing events. The lower further decompensation rate with TIPS was confirmed by adjusted IPD meta-analysis (hazard ratio 0.44; 95% CI 0.37-0.54) and was consistent across TIPS indication subgroups. The 2-year cumulative survival probability was higher with TIPS than with SOC (0.71 vs. 0.63; p = 0.0001).

CONCLUSIONS

The use of TIPS for refractory ascites and for prevention of variceal rebleeding reduces the incidence of a further decompensation event compared with SOC and increases survival in highly selected patients.

IMPACT AND IMPLICATIONS

A further decompensation (new or worsening ascites, variceal bleeding or rebleeding, hepatic encephalopathy, jaundice, hepatorenal syndrome-acute kidney injury and spontaneous bacterial peritonitis) in patients with cirrhosis is associated with a poor prognosis. Besides the known role of TIPS in portal hypertension-related complications, this study shows that TIPS is also able to decrease the overall risk of a further decompensation and increase survival compared with standard of care. These results further support the role of TIPS in the management of patients with cirrhosis and portal hypertension-related complications.

Endoscopic diagnosis and management of esophagogastric variceal hemorrhage: European Society of Gastrointestinal Endoscopy (ESGE) Guideline

1: ESGE recommends that patients with compensated advanced chronic liver disease (ACLD; due to viruses, alcohol, and/or nonobese [BMI < 30 kg/m²] nonalcoholic steatohepatitis) and clinically significant portal hypertension (hepatic venous pressure gradient [HVPG] > 10 mmHg and/or liver stiffness by transient elastography > 25 kPa) should receive, if no contraindications, nonselective beta blocker (NSBB) therapy (preferably carvedilol) to prevent the development of variceal bleeding.Strong recommendation, moderate quality evidence. 2: ESGE recommends that in those patients unable to receive NSBB therapy with a screening upper gastrointestinal (GI) endoscopy that demonstrates high risk esophageal varices, endoscopic band ligation (EBL) is the endoscopic prophylactic treatment of choice. EBL should be repeated every 2-4 weeks until variceal eradication is achieved. Thereafter, surveillance EGD should be performed every 3-6 months in the first year following eradication.Strong recommendation, moderate quality evidence. 3: ESGE recommends, in hemodynamically stable patients with acute upper GI hemorrhage (UGIH) and no history of cardiovascular disease, a restrictive red blood cell (RBC) transfusion strategy, with a hemoglobin threshold of ≤ 70 g/L prompting RBC transfusion. A post-transfusion target hemoglobin of 70-90 g/L is desired.Strong recommendation, moderate quality evidence. 4 : ESGE recommends that patients with ACLD presenting with suspected acute variceal bleeding be risk stratified according to the Child-Pugh score and MELD score, and by documentation of active/inactive bleeding at the time of upper GI endoscopy.Strong recommendation, high quality of evidence. 5 : ESGE recommends the vasoactive agents terlipressin, octreotide, or somatostatin be initiated at the time of presentation in patients with suspected acute variceal bleeding and be continued for a duration of up to 5 days.Strong recommendation, high quality evidence. 6 : ESGE recommends antibiotic prophylaxis using ceftriaxone 1 g/day for up to 7 days for all patients with ACLD presenting with acute variceal hemorrhage, or in accordance with local antibiotic resistance and patient allergies.Strong recommendation, high quality evidence. 7 : ESGE recommends, in the absence of contraindications, intravenous erythromycin 250 mg be given 30-120 minutes prior to upper GI endoscopy in patients with suspected acute variceal hemorrhage.Strong recommendation, high quality evidence. 8 : ESGE recommends that, in patients with suspected variceal hemorrhage, endoscopic evaluation should take place within 12 hours from the time of patient presentation provided the patient has been hemodynamically resuscitated.Strong recommendation, moderate quality evidence. 9 : ESGE recommends EBL for the treatment of acute esophageal variceal hemorrhage (EVH).Strong recommendation, high quality evidence. 10 : ESGE recommends that, in patients at high risk for recurrent esophageal variceal bleeding following successful endoscopic hemostasis (Child-Pugh C  ≤ 13 or Child-Pugh B > 7 with active EVH at the time of endoscopy despite vasoactive agents, or HVPG > 20 mmHg), pre-emptive transjugular intrahepatic portosystemic shunt (TIPS) within 72 hours (preferably within 24 hours) must be considered.Strong recommendation, high quality evidence. 11 : ESGE recommends that, for persistent esophageal variceal bleeding despite vasoactive pharmacological and endoscopic hemostasis therapy, urgent rescue TIPS should be considered (where available).Strong recommendation, moderate quality evidence. 12 : ESGE recommends endoscopic cyanoacrylate injection for acute gastric (cardiofundal) variceal (GOV2, IGV1) hemorrhage.Strong recommendation, high quality evidence. 13: ESGE recommends endoscopic cyanoacrylate injection or EBL in patients with GOV1-specific bleeding.Strong recommendations, moderate quality evidence. 14: ESGE suggests urgent rescue TIPS or balloon-occluded retrograde transvenous obliteration (BRTO) for gastric variceal bleeding when there is a failure of endoscopic hemostasis or early recurrent bleeding.Weak recommendation, low quality evidence. 15: ESGE recommends that patients who have undergone EBL for acute EVH should be scheduled for follow-up EBLs at 1- to 4-weekly intervals to eradicate esophageal varices (secondary prophylaxis).Strong recommendation, moderate quality evidence. 16: ESGE recommends the use of NSBBs (propranolol or carvedilol) in combination with endoscopic therapy for secondary prophylaxis in EVH in patients with ACLD.Strong recommendation, high quality evidence.

Thromboprophylaxis for venous thromboembolism prevention in hospitalized patients with cirrhosis: Guidance from the SSC of the ISTH

Hospital-associated venous thromboembolism (HA-VTE) is a major cause of morbidity and mortality and is internationally recognized as a significant patient safety issue. While cirrhosis was traditionally considered to predispose to bleeding, these patients are also at an increased risk of VTE, with an associated increase in mortality. Hospitalization rates of patients with cirrhosis are increasing, and decisions regarding thromboprophylaxis are complex due to the uncertain balance between thrombosis and bleeding risk. This is further accentuated by derangements of hemostasis in patients with cirrhosis that are often considered contraindications to pharmacological thromboprophylaxis. Due to the strict inclusion and exclusion criteria of seminal studies of VTE risk assessment and thromboprophylaxis, there is limited data to guide decision making in this patient group. This guidance document reviews the incidence and risk factors for HA-VTE in patients with cirrhosis, outlines evidence to inform the use of thromboprophylaxis, and provides pragmatic recommendations on VTE prevention for hospitalized patients with cirrhosis. In brief, in hospitalized patients with cirrhosis: We suggest inclusion of portal vein thrombosis as a distinct clinically important endpoint for future studies. We recommend against the use of thrombocytopenia and/or prolongation of prothrombin time/international normalized ratio as absolute contraindications to anticoagulant thromboprophylaxis. We suggest anticoagulant thromboprophylaxis in line with local protocols and suggest low molecular weight heparin (LMWH) or fondaparinux over unfractionated heparin (UFH). In renal impairment, we suggest LMWH over UFH. For critically ill patients, we suggest case-by-case consideration of thromboprophylaxis. We recommend research to refine VTE risk stratification, and to establish the optimal dosing and duration of thromboprophylaxis.

Decompensation in Advanced Nonalcoholic Fatty Liver Disease May Occur at Lower Hepatic Venous Pressure Gradient Levels Than in Patients With Viral Disease

BACKGROUND & AIMS

Portal hypertension is the strongest predictor of hepatic decompensation and death in patients with cirrhosis. However, its discriminatory accuracy in patients with nonalcoholic fatty liver disease (NAFLD) has been challenged because hepatic vein catheterization may not reflect the real portal vein pressure as accurately as in patients with other etiologies. We aimed to evaluate the relationship between hepatic venous pressure gradient (HVPG) and presence of portal hypertension-related decompensation in patients with advanced NAFLD (aNAFLD).

METHODS

Multicenter cross-sectional study included 548 patients with aNAFLD and 444 with advanced RNA-positive hepatitis C (aHCV) who had detailed portal hypertension evaluation (HVPG measurement, gastroscopy, and abdominal imaging). We examined the relationship between etiology, HVPG, and decompensation by logistic regression models. We also compared the proportions of compensated/decompensated patients at different HVPG levels.

RESULTS

Both cohorts, aNAFLD and aHVC, had similar baseline age, gender, Child-Pugh score, and Model for End-Stage Liver Disease score. Median HVPG was lower in the aNAFLD cohort (13 vs 15 mmHg) despite similar liver function and higher rates of decompensation in aNAFLD group (32% vs 25%; P = .019) than in the aHCV group. For any of the HVPG cutoff analyzed (<10, 10-12, or 12 mmHg) the prevalence of decompensation was higher in the aNAFLD group than in the aHCV group.

CONCLUSIONS

Patients with aNAFLD have higher prevalence of portal hypertension-related decompensation at any value of HVPG as compared with aHCV patients. Longitudinal studies aiming to identify HVPG thresholds able to predict decompensation and long-term outcomes in aNAFLD population are strongly needed.

Periprocedural management of abnormal coagulation parameters and thrombocytopenia in patients with cirrhosis: Guidance from the SSC of the ISTH

Prolonged prothrombin time and thrombocytopenia are common in patients with cirrhosis. These parameters do not reflect the overall hemostatic rebalance or bleeding risk in the periprocedural setting; however, attempts to correct these parameters remain frequent. We review the literature on periprocedural bleeding risk, bleeding risk factors, and the risk and benefits of hemostatic interventions in patients with cirrhosis. We provide guidance recommendations on evaluating bleeding risk in this patient group and management of hemostatic abnormalities in the periprocedural setting.

Predicting portal thrombosis in cirrhosis: A prospective study of clinical, ultrasonographic and hemostatic factors

BACKGROUND & AIMS

Portal vein thrombosis (PVT) is a relatively frequent event in patients with cirrhosis. While different risk factors for PVT have been reported, such as decreased portal blood flow velocity (PBFV) and parameters related with severity of portal hypertension, these are based on retrospective studies assessing only a discrete number of parameters. The aim of the current study was to evaluate the incidence and risks factors for non-tumoral PVT development in a large prospective cohort of patients with cirrhosis.

METHODS

We performed an exhaustive evaluation of clinical, biochemical, inflammatory and acquired/hereditary hemostatic profiles in 369 patients with cirrhosis without PVT who were prospectively followed-up. Doppler ultrasound was performed at baseline and every 6 months or whenever clinically indicated. PVT development was always confirmed by computed tomography.

RESULTS

Twenty-nine patients developed non-tumoral PVT, with an incidence of 1.6%, 6% and 8.4% at 1, 3 and 5 years, respectively. Low platelet count, PBFV <15 cm/sec and history of variceal bleeding were factors independently associated with a high PVT risk. No relationship between PVT development and any other clinical biochemical, inflammatory and acquired or hereditary hemostatic parameter was found.

CONCLUSIONS

In patients with cirrhosis, the factors predictive of PVT development were mainly those related to the severity of portal hypertension. Our results do not support the role of hemostatic alterations (inherited or acquired) and inflammatory markers in the prediction of PVT in patients with cirrhosis.

LAY SUMMARY

Patients with cirrhosis and more severe portal hypertension are at higher risk of non-tumoral portal vein thrombosis development. Acquired or inherited hemostatic disorders, as well as inflammatory status, do not seem to predict the development of portal vein thrombosis in patients with cirrhosis.

Complement and coagulation cascades activation is the main pathophysiological pathway in early-onset severe preeclampsia revealed by maternal proteomics

Preeclampsia is a pregnancy-specific multisystem disorder and a leading cause of maternal and perinatal morbidity and mortality. The exact pathogenesis of this multifactorial disease remains poorly defined. We applied proteomics analysis on maternal blood samples collected from 14 singleton pregnancies with early-onset severe preeclampsia and 6 uncomplicated pregnancies to investigate the pathophysiological pathways involved in this specific subgroup of preeclampsia. Maternal blood was drawn at diagnosis for cases and at matched gestational age for controls. LC-MS/MS proteomics analysis was conducted, and data were analyzed by multivariate and univariate statistical approaches with the identification of differential pathways by exploring the global human protein-protein interaction network. The unsupervised multivariate analysis (the principal component analysis) showed a clear difference between preeclamptic and uncomplicated pregnancies. The supervised multivariate analysis using orthogonal partial least square discriminant analysis resulted in a model with goodness of fit (R2X = 0.99, p < 0.001) and a strong predictive ability (Q2Y = 0.8, p < 0.001). By univariate analysis, we found 17 proteins statistically different after 5% FDR correction (q-value < 0.05). Pathway enrichment analysis revealed 5 significantly enriched pathways whereby the activation of the complement and coagulation cascades was on top (p = 3.17e-07). To validate these results, we assessed the deposits of C5b-9 complement complex and on endothelial cells that were exposed to activated plasma from an independent set of 4 cases of early-onset severe preeclampsia and 4 uncomplicated pregnancies. C5b-9 and Von Willbrand factor deposits were significantly higher in early-onset severe preeclampsia. Future studies are warranted to investigate potential therapeutic targets for early-onset severe preeclampsia within the complement and coagulation pathway.

Sinusoidal obstruction syndrome

Sinusoidal obstruction syndrome (SOS), previously known as veno-occlusive disease, is characterized by concentric and non-thrombotic obstruction of the sinusoid and central vein lumen with no identified primitive or thrombotic hepatic vein lesions. The initial lesion is a result of endothelial denudation, corresponding to the migration of damaged sinusoidal cells to the central veins of the hepatic lobules, leading to sinusoidal and veno-occlusive congestive obstruction. SOS may be associated with other lesions such as centrilobular perisinusoidal fibrosis, peliosis, or nodular regenerative hyperplasia. The first cases of SOS were documented in 1920 in South Africa, after ingestion of food sources contaminated by pyrrolizidine alkaloids. SOS is a well-known complication of hematopoietic stem cell transplantation (HSCT). Numerous toxins and drugs have been associated with SOS, mainly chemotherapies and immunosuppressive therapies, as well as total body or liver irradiation and ABO mismatch platelet transfusion. The pathogenesis of this entity remains unknown.

Portal cavernoma or chronic non cirrhotic extrahepatic portal vein obstruction

Chronic non cirrhotic extrahepatic portal vein obstruction (EHPVO) refers to the cavernomatous transformation of the portal vein (the so-called "portal cavernoma") which occurs following acute thrombosis of the portal vein in the absence of recanalization. In adults, EHPVO mainly occurs following thrombosis, while in children it may be related to congenital malformations and/or neonatal umbilical venous catheterization. However, 50% of the cases of EHPVO remain idiopathic [1]. Risk factors and associated diseases should be investigated (chapter 1). Indeed, the presence of a thrombophilic alteration, in particular myeloproliferative neoplasm impacts prognosis and determine a causal treatment.

Porto-sinusoidal vascular disease: proposal and description of a novel entity

Portal hypertension in the absence of portal vein thrombosis and without cirrhosis, but with mild or moderate alterations of liver histology (eg, obliterative venopathy, nodular regenerative hyperplasia, or incomplete septal cirrhosis) is being increasingly recognised. Owing to the heterogeneity of causes and histological findings, a substantial number of terms have been used to describe such idiopathic non-cirrhotic portal hypertension. Patients with the same clinical and histological features exist, but without portal hypertension at the time of diagnosis. Therefore, improved criteria are needed to define this form of liver disease. Here, we propose the term porto-sinusoidal vascular disease, since all lesions found involve the portal venules or sinusoids. The definition of this entity is based on the characteristic absence of cirrhosis with or without signs of portal hypertension or histological lesions. The presence of known causes of liver disease does not rule out porto-sinusoidal vascular disease, but specific causes of vascular liver disease are excluded from its definition. The diagnosis of porto-sinusoidal vascular disease is based on liver biopsy and might include signs specific for portal hypertension with normal or mildly elevated liver stiffness values and no complete portal vein thrombosis. We provide simple diagnostic criteria, because agreement on a uniform nomenclature is an essential requirement for future collaborative studies.

Natural history of polycythemia vera and essential thrombocythemia presenting with splanchnic vein thrombosis

Patients with polycythemia vera (PV) or essential thrombocythemia (ET) presenting with splanchnic vein thrombosis (SVT) might have a specific clinico-biological profile. To investigate this hypothesis, 3705 PV/ET patients from three national registers, 118 of them presenting with SVT, were reviewed. After correction for age and sex, PV/ET patients with SVT showed an increased risk of death (HR 2.47, 95% CI 1.5-4.01, p < 0.001), venous thrombosis (IRR 3.4, 95%CI 2.1-5.5, p < 0.001), major bleeding (IRR 3.6, 95%CI 2.3-5.5, p < 0.001), and second cancer (IRR 2.37, 95%CI 1.4-4.1, p = 0.002). No case of acute leukemia was documented among patients with PV/ET presenting with SVT and seven of them (6%) progressed to myelofibrosis. SVT was not associated with lower risk of MF after correction by age and sex. Patients with SVT more frequently died from complications related to hepatic disease, major bleeding, or second cancer, resulting in a 5-year reduction of age- and sex-adjusted median survival. In conclusion, PV and ET patients presenting with SVT have shorter survival than patients with PV and ET of the same age and sex. This excess mortality is related to liver disease, major bleeding, and second cancer rather than to the natural evolution of the MPN.

Association Between Portosystemic Shunts and Increased Complications and Mortality in Patients With Cirrhosis

BACKGROUND & AIMS

Spontaneous portosystemic shunts (SPSS) have been associated with hepatic encephalopathy (HE). Little is known about their prevalence among patients with cirrhosis or clinical effects. We investigated the prevalence and characteristics of SPSS in patients with cirrhosis and their outcomes.

METHODS

We performed a retrospective study of 1729 patients with cirrhosis who underwent abdominal computed tomography or magnetic resonance imaging analysis from 2010 through 2015 at 14 centers in Canada and Europe. We collected data on demographic features, etiology of liver disease, comorbidities, complications, treatments, laboratory and clinical parameters, Model for End-Stage Liver Disease (MELD) score, and endoscopy findings. Abdominal images were reviewed by a radiologist (or a hepatologist trained by a radiologist) and searched for the presence of SPSS, defined as spontaneous communications between the portal venous system or splanchnic veins and the systemic venous system, excluding gastroesophageal varices. Patients were assigned to groups with large SPSS (L-SPSS, ≥8 mm), small SPSS (S-SPSS, <8 mm), or without SPSS (W-SPSS). The main outcomes were the incidence of complications of cirrhosis and mortality according to the presence of SPSS. Secondary measurements were the prevalence of SPSS in patients with cirrhosis and their radiologic features.

RESULTS

L-SPSS were identified in 488 (28%) patients, S-SPSS in 548 (32%) patients, and no shunt (W-SPSS) in 693 (40%) patients. The most common L-SPSS was splenorenal (46% of L-SPSS). The presence and size of SPSS increased with liver dysfunction: among patients with MELD scores of 6-9, 14% had L-SPSS and 28% had S-SPSS; among patients with MELD scores of 10-13, 30% had L-SPSS and 34% had S-SPSS; among patients with MELD scores of 14 or higher, 40% had L-SPSS and 32% had S-SPSS (P < .001 for multiple comparison among MELD groups). HE was reported in 48% of patients with L-SPSS, 34% of patients with S-SPSS, and 20% of patients W-SPSS (P < .001 for multiple comparison among SPSS groups). Recurrent or persistent HE was reported in 52% of patients with L-SPSS, 44% of patients with S-SPSS, and 37% of patients W-SPSS (P = .007 for multiple comparison among SPSS groups). Patients with SPSS also had a larger number of portal hypertension-related complications (bleeding or ascites) than those W-SPSS. Quality of life and transplantation-free survival were lower in patients with SPSS vs without. SPSS were an independent factor associated with death or liver transplantation (hazard ratio, 1.26; 95% confidence interval, 1.06-1.49) (P = .008) in multivariate analysis. When patients were stratified by MELD score, SPSS were associated with HE independently of liver function: among patients with MELD scores of 6-9, HE was reported in 23% with L-SPSS, 12% with S-SPSS, and 5% with W-SPSS (P < .001 for multiple comparison among SPSS groups); among those with MELD scores of 10-13, HE was reported in 48% with L-SPSS, 33% with S-SPSS, and 23% with W-SPSS (P < .001 for multiple comparison among SPSS groups); among patients with MELD scores of 14 or more, HE was reported in 59% with L-SPSS, 57% with S-SPSS, and 48% with W-SPSS (P = .043 for multiple comparison among SPSS groups). Patients with SPSS and MELD scores of 6-9 were at higher risk for ascites (40.5% vs 23%; P < .001) and bleeding (15% vs 9%; P = .038) than patients W-SPSS and had lower odds of transplant-free survival (hazard ratio 1.71; 95% confidence interval, 1.16-2.51) (P = .006).

CONCLUSIONS

In a retrospective analysis of almost 2000 patients, we found 60% to have SPSS; prevalence increases with deterioration of liver function. SPSS increase risk for HE and with a chronic course. In patients with preserved liver function, SPSS increase risk for complications and death. ClinicalTrials.gov ID NCT02692430.

Timing Affects Measurement of Portal Pressure Gradient After Placement of Transjugular Intrahepatic Portosystemic Shunts in Patients With Portal Hypertension

BACKGROUND & AIMS

A reduction in portal pressure gradient (PPG) to <12 mm Hg after placement of a transjugular intrahepatic portosystemic shunt (TIPS) correlates with the absence of further bleeding or ascites at follow-up examinations of patients with cirrhosis. The PPG is usually measured immediately after placement of the TIPS, when different circumstances can affect PPG values, which could affect determination of risk for decompensation. We investigated variations in PPG measurements collected at different time points after TIPS, aiming to identify a time point after which PPG values were best maintained.

METHODS

We performed a retrospective study of 155 consecutive patients with severe complications of portal hypertension who received placement of TIPS from January 2008 through October 2015; patients were followed until March 2016. We compared PPG values measured at different time points and under different conditions: immediately after placement of TIPS (immediate PPG); at least 24 hours after placement to TIPS into hemodynamically stable patients, without sedation (early PPG); and again 1 month after TIPS placement (late PPG).

RESULTS

The immediate PPG differed significantly from the early PPG, regardless of whether the TIPS was placed using general anesthesia (8.5 ± 3.5 mm Hg vs 10 ± 3.5 mm Hg; P = .015) or deep sedation (12 ± 4 mm Hg vs 10.5 ± 4 mm Hg; P <.001). In considering the 12 mm Hg threshold, concordance between immediate PPG and early PPG values was poor. However, there was no significant difference between mean early PPG and late PPG values (8.5 ± 2.5 mm Hg vs 8 ± 3 mm Hg), or between proportions of patients with early PPG vs late PPG values <12 mm Hg threshold. Maintenance of a PPG value <12 mm Hg during the follow-up period was associated with a lower risk of recurrent or de novo variceal bleeding or ascites (hazard ratio, 0.11; 95% confidence interval, 0.04 0.27; P < .001).

CONCLUSIONS

In a retrospective study of patients with PPG values measured at different time points after TIPS placement, we found measurements of PPG in awake, hemodynamically stable patients at least 24 hours after TIPS to be the best maintained values. Our findings support the concept that PPG value <12 mm Hg after TIPS placement is associated with reduced risk of bleeding and ascites.

A randomized trial to assess whether portal pressure guided therapy to prevent variceal rebleeding improves survival in cirrhosis

Monitoring the hemodynamic response of portal pressure (PP) to drug therapy accurately stratifies the risk of variceal rebleeding (VRB). We assessed whether guiding therapy with hepatic venous pressure gradient (HVPG) monitoring may improve survival by preventing VRB. Patients with cirrhosis with controlled variceal bleeding were randomized to an HVPG-guided therapy group (N = 84) or to a control group (N = 86). In both groups, HVPG and acute β-blocker response were evaluated at baseline and HVPG measurements were repeated at 2-4 weeks to determine chronic response. In the HVPG-guided group, acute responders were treated with nadolol and acute nonresponders with nadolol+nitrates. Chronic nonresponders received nadolol+prazosin and had a third HVPG study. Ligation sessions were repeated until response was achieved. The control group was treated with nadolol+nitrates+ligation. Between-group baseline characteristics were similar. During long-term follow-up (median of 24 months), mortality was lower in the HVPG-guided therapy group than in the control group (29% vs. 43%; hazard ratio [HR] = 0.59; 95% confidence interval [CI] = 0.35-0.99). Rebleeding occurred in 19% versus 31% of patients, respectively (HR = 0.53; 95% CI = 0.29-0.98), and further decompensation of cirrhosis occurred in 52% versus 72% (HR = 0.68; 95% CI = 0.46-0.99). The survival probability was higher with HVPG-guided therapy than in controls, both in acute (HR = 0.59; 95% CI = 0.32-1.08) and chronic nonresponders (HR = 0.48; 95% CI = 0.23-0.99). HVPG-guided patients had a greater reduction of HVPG and a lower final value than controls (P < 0.05).

CONCLUSION

HVPG monitoring, by stratifying risk and targeting therapy, improves the survival achieved with currently recommended treatment to prevent VRB using β-blockers and ligation. HVPG-guided therapy achieved a greater reduction in PP, which may have contributed to reduce the risk of rebleeding and of further decompensation of cirrhosis, thus contributing to a better survival. (Hepatology 2017;65:1693-1707).

Relative adrenal insufficiency in severe acute variceal and non-variceal bleeding: influence on outcomes

BACKGROUND & AIMS

Relative adrenal insufficiency (RAI) is common in critical illness and in cirrhosis, and is related with worse outcomes. The prevalence of RAI may be different in variceal and non-variceal bleeding and whether it may influence outcomes in these settings is unclear. This study assesses RAI and its prognostic implications in cirrhosis with variceal bleeding and in peptic ulcer bleeding.

METHODS

Patients with severe bleeding (systolic pressure <100 mmHg and/or haemoglobin <8 g/L) from oesophageal varices or from a peptic ulcer were included. Adrenal function was evaluated within the first 24 h and RAI was diagnosed as delta cortisol <250 nmol/L after 250 μg of i.v. corticotropin.

RESULTS

Sixty-two patients were included, 36 had cirrhosis and variceal bleeding and 26 without cirrhosis had ulcer bleeding. Overall, 15 patients (24%) had RAI, 8 (22%) with variceal and 7 (24%) with ulcer bleeding. Patients with RAI had higher rate of bacterial infections. Baseline serum and salivary cortisol were higher in patients with RAI (P < 0.001) while delta cortisol was lower (P < 0.001). There was a good correlation between plasma and salivary cortisol (P < 0.001). The probability of 45-days survival without further bleeding was lower in cirrhotic patients with variceal bleeding and RAI than in those without RAI (25% vs 68%, P = 0.02), but not in non-cirrhotic patients with peptic ulcer bleeding with or without RAI (P = 0.75).

CONCLUSION

The prevalence of RAI is similar in ulcer bleeding and in cirrhosis with variceal bleeding. Cirrhotic patients with RAI, but not those with bleeding ulcers, have worse prognosis.

DNA methylation-based prognosis and epidrivers in hepatocellular carcinoma

Epigenetic deregulation has emerged as a driver in human malignancies. There is no clear understanding of the epigenetic alterations in hepatocellular carcinoma (HCC) and of the potential role of DNA methylation markers as prognostic biomarkers. Analysis of tumor tissue from 304 patients with HCC treated with surgical resection allowed us to generate a methylation-based prognostic signature using a training-validation scheme. Methylome profiling was done with the Illumina HumanMethylation450 array (Illumina, Inc., San Diego, CA), which covers 96% of known cytosine-phosphate-guanine (CpG) islands and 485,000 CpG, and transcriptome profiling was performed with Affymetrix Human Genome U219 Plate (Affymetrix, Inc., Santa Clara, CA) and miRNA Chip 2.0. Random survival forests enabled us to generate a methylation signature based on 36 methylation probes. We computed a risk score of mortality for each individual that accurately discriminated patient survival both in the training (221 patients; 47% hepatitis C-related HCC) and validation sets (n = 83; 47% alcohol-related HCC). This signature correlated with known predictors of poor outcome and retained independent prognostic capacity of survival along with multinodularity and platelet count. The subset of patients identified by this signature was enriched in the molecular subclass of proliferation with progenitor cell features. The study confirmed a high prevalence of genes known to be deregulated by aberrant methylation in HCC (e.g., Ras association [RalGDS/AF-6] domain family member 1, insulin-like growth factor 2, and adenomatous polyposis coli) and other solid tumors (e.g., NOTCH3) and describes potential candidate epidrivers (e.g., septin 9 and ephrin B2).

CONCLUSIONS

A validated signature of 36 DNA methylation markers accurately predicts poor survival in patients with HCC. Patients with this methylation profile harbor messenger RNA-based signatures indicating tumors with progenitor cell features.

Real-time shear-wave elastography: applicability, reliability and accuracy for clinically significant portal hypertension

BACKGROUND & AIMS

Real-time shear wave elastography (RT-SWE) might be useful to assess the severity of portal hypertension; reliability criteria for measurement are needed.

METHODS

We prospectively included 88 consecutive patients undergoing hepatic venous pressure gradient measurement (HVPG, reference standard) for portal hypertension. Liver stiffness (LS) was measured by RT-SWE and by transient elastography (TE). Spleen stiffness (SS) was measured by RT-SWE. Reliability criteria for RT-SWE were searched, and the accuracy of these techniques to identify HVPG ⩾10mmHg (clinically significant portal hypertension, CSPH) was tested and internally validated by bootstrapping analysis.

RESULTS

LS and SS by RT-SWE were feasible respectively in 87 (99%) and 58 (66%) patients. Both correlated with HVPG (LS: R=0.611, p<0.0001 and SS: R=0.514, p<0.0001). LS performed well for diagnosing CSPH (optimism corrected AUROC=0.858). Reliability of measurements was influenced by standard deviation (SD)/median ratio and depth. SD/median ⩽0.10 and depth of measurement <5.6cm were associated to 96.3% well classified for CSPH, while when one or none of the criteria were fulfilled the rates were 76.4% and 44.4%, respectively. Measurements fulfilling at least one criterion were considered acceptable; in these patients, RT-SWE performance to detect CSPH was excellent (AUROC=0.939; 95% CI: 0.865-1.000; p<0.0001; best cut-off: 15.4kPa). LS by RT-SWE and by TE were strongly correlated (R=0.795, p<0.0001) and performed similarly both in "per protocol" and in "intention-to-diagnose" analysis after applying reliability criteria.

CONCLUSIONS

LS by RT-SWE is an accurate method to diagnose CSPH if reliability criteria (SD/median ⩽0.10 and/or depth <5.6cm) are fulfilled.

Transjugular liver biopsy

Liver biopsy is still the gold standard for evaluation of acute and chronic liver diseases, despite achievements regarding noninvasive diagnosis and staging in liver diseases. Transjugular liver biopsy (TJLB) has proved a good option when ascites and/or significant coagulopathy precludes a percutaneous approach. Because diagnostic hemodynamic procedures can be performed during the same session, it is useful in many clinical settings, regardless of the absence of percuteaneous contraindications. TJLB is a safe technique able to provide good-quality specimens with a low rate of complications. This article presents an overview of TJLB that discusses the technique, applicability, indications, contraindications, complications, and diagnostic accuracy.

Unexpected disappearance of portal cavernoma on long-term anticoagulation

Idiopathic non-cirrhotic portal hypertension is a rare disease of unknown etiology. Patients with idiopathic non-cirrhotic portal hypertension have an increased risk of developing portal vein thrombosis and this is especially prevalent when HIV is also present. We describe a unique case of a patient with idiopathic non-cirrhotic portal hypertension associated to HIV, who developed acute portal vein thrombosis that despite anticoagulation transformed in portal cavernoma and disappeared completely after five years of follow-up on continuous anticoagulation.

Idiopathic portal hypertension: natural history and long-term outcome

Idiopathic portal hypertension (IPH) is a rare cause of intrahepatic portal hypertension. Data on natural history and prognosis of IPH are limited. We sought to describe the complications and long-tem outcome of IPH by retrospectively studying 69 biopsy-proven cases of IPH. Mean duration of follow-up was 6.7 ± 4.6 years. All patients had evidence of portal hypertension (PH) at diagnosis, and 42% were symptomatic. Variceal bleeding (VB) was the most common manifestation. In those without bleeding at diagnosis, 74% had varices at first endoscopy. In those with large varices, the 1-year probability of first bleeding despite primary prophylaxis was 9%. The 1-year probability of rebleeding was 22%. Ascites and hepatic encephalopathy was documented in 26% and 7% of patients, respectively, at least once during the clinical course. The 1-year probability of developing portal vein thrombosis (PVT) was 9%, and 53% of patients receiving anticoagulation achieved recanalization. Human immunodeficiency virus (HIV) infection and VB at diagnosis were the independent predictors of PVT. Seven patients died (6 as a result of an IPH-related cause) and 2 were transplanted. Probability of liver transplantation-free survival was 82% at 10 years. Presence of a severe associated disorder and ascites as a presenting symptom were associated with poor survival.

CONCLUSION

Variceal bleeding is a major complication of IPH. Using, in IPH patients, the same management approach for PH as in cirrhosis is safe and maintains a low incidence of first bleeding and rebleeding in IPH patients. PVT is a frequent complication, particularly in those with HIV infection. Despite several complications, overall survival of patients with IPH is considerably good.

Hepatocellular carcinoma: reasons for phase III failure and novel perspectives on trial design

Hepatocellular carcinoma (HCC) is a major health problem. Most patients with HCC experience a recurrence after resection/ablation or are diagnosed at advanced stages. Sorafenib remains the only approved systemic drug for these patients. Molecular therapies targeting signaling cascades involved in hepatocarcinogenesis have been explored in phase III clinical trials. However, none of the drugs tested have shown positive results in the first-line (brivanib, sunitinib, erlotinib, and linifanib) or second-line (brivanib, everolimus) setting after sorafenib progression. Reasons for failure are heterogeneous and include lack of understanding of critical drivers of tumor progression/dissemination, liver toxicity, flaws in trial design, or marginal antitumoral potency. These trials are also challenging time to progression as a surrogate endpoint of survival. Trials ongoing testing drugs head-to-head versus sorafenib in "all comers" might have difficulties in achieving superior results in the first line. Novel trials are also designed testing drugs in biomarker-based subpopulations of patients with HCC. Most common mutations, however, are undruggable, such as p53 and CTNNB1. Two types of studies are proposed: (i) phase II pivotal proof-of-concept studies testing drugs blocking potential oncogenic addiction loops, such as the one testing MEK inhibitors in RAS(+) patients or amplification of FGF19 as a target; and (ii) phase II to III studies using biomarker-based trial enrichment for defining HCC subpopulations, such as the case of enriching for MET-positive tumors. These strategies have been deemed successful in breast, melanoma, and lung cancers, and are expected to change the landscape of trial design of HCC.

Role of the microenvironment in the pathogenesis and treatment of hepatocellular carcinoma

Hepatocellular carcinoma (HCC) is the most common primary liver tumor and the third greatest cause of cancer-related death worldwide, and its incidence is increasing. Despite the significant improvement in management of HCC over the past 30 years, there are no effective chemoprevention strategies, and only one systemic therapy has been approved for patients with advanced tumors. This drug, sorafenib, acts on tumor cells and the stroma. HCC develops from chronically damaged tissue that contains large amounts of inflammation and fibrosis, which also promote tumor progression and resistance to therapy. Increasing our understanding of how stromal components interact with cancer cells and the signaling pathways involved could help identify new therapeutic and chemopreventive targets.

Management of small hepatocellular carcinoma in cirrhosis: Focus on portal hypertension

The incidence of hepatocellular carcinoma (HCC) is rising worldwide being currently the fifth most common cancer and third cause of cancer-related mortality. Early detection of HCC through surveillance programs have enabled the identification of small nodules with higher frequency, and nowadays account for 10%-15% of patients diagnosed in the West and almost 30% in Japan. Patients with small HCC can be candidates for potential curative treatments: liver transplantation, surgical resection and percutaneous ablation, depending on the presence of portal hypertension and co-morbidities. This review will analyze recent advancements in the clinical management of these individuals, focusing on issues related to the role of portal hypertension, the debate between resection and ablative therapies and the future impact of molecular technologies.

Reduced hepatic stellate cell expression of Kruppel-like factor 6 tumor suppressor isoforms amplifies fibrosis during acute and chronic rodent liver injury

Kruppel-like factor 6 (KLF6), a zinc finger transcription factor and tumor suppressor, is induced as an immediate-early gene during hepatic stellate cell (HSC) activation. The paradoxical induction of a tumor suppressor in HSCs during proliferation led us to explore the biology of wildtype KLF6 (KLF6(WT) ) and its antagonistic, alternatively spliced isoform KLF6(SV1) in cultured HSCs and animal models. The animal models generated include a global heterozygous KLF6 mouse (Klf6+/-), and transgenic mice expressing either hKLF6(WT) or hKLF6(SV1) under the control of the Collagen α2 (I) promoter to drive HSC-specific gene expression following injury. The rat Klf6 transcript has multiple splice forms that are homologous to those of the human KLF6 gene. Following a transient increase, all rat Klf6 isoforms decreased in response to acute carbon tetrachloride (CCl(4)) liver injury and culture-induced activation. After acute CCl(4), Klf6+/- mice developed significantly increased fibrosis and enhanced fibrogenic messenger RNA (mRNA) and protein expression. In contrast, HSC-specific transgenic mice overexpressing KLF6(WT) or KLF6(SV1) developed significantly diminished fibrosis with reduced expression of fibrogenic genes. Chromatin IP and quantitative reverse-transcription polymerase chain reaction in mouse HSCs overexpressing KLF6(WT) demonstrated KLF6(WT) binding to GC boxes in promoters of Colα1 (I), Colα2 (I), and beta-platelet-derived growth factor receptor (β-Pdgfr) with reduced gene expression, consistent with transcriptional repression by KLF6. Stellate cells overexpressing either KLF6(WT) or KLF6(SV1) were more susceptible to apoptotic stress based on poly (ADP-ribose) polymerase (PARP) cleavage.

CONCLUSION

KLF6 reduces fibrogenic activity of HSCs by way of two distinct mechanisms, direct transcriptional repression of target fibrogenic genes and increased apoptosis of activated HSCs. These results suggest that following its initial induction, sustained down-regulation of KLF6 in liver injury may allow de-repression of fibrogenic genes and decreased stellate cell clearance by inhibiting apoptosis.

Transfusion strategies for acute upper gastrointestinal bleeding

BACKGROUND

The hemoglobin threshold for transfusion of red cells in patients with acute gastrointestinal bleeding is controversial. We compared the efficacy and safety of a restrictive transfusion strategy with those of a liberal transfusion strategy.

METHODS

We enrolled 921 patients with severe acute upper gastrointestinal bleeding and randomly assigned 461 of them to a restrictive strategy (transfusion when the hemoglobin level fell below 7 g per deciliter) and 460 to a liberal strategy (transfusion when the hemoglobin fell below 9 g per deciliter). Randomization was stratified according to the presence or absence of liver cirrhosis.

RESULTS

A total of 225 patients assigned to the restrictive strategy (51%), as compared with 61 assigned to the liberal strategy (14%), did not receive transfusions (P<0.001) [corrected].The probability of survival at 6 weeks was higher in the restrictive-strategy group than in the liberal-strategy group (95% vs. 91%; hazard ratio for death with restrictive strategy, 0.55; 95% confidence interval [CI], 0.33 to 0.92; P=0.02). Further bleeding occurred in 10% of the patients in the restrictive-strategy group as compared with 16% of the patients in the liberal-strategy group (P=0.01), and adverse events occurred in 40% as compared with 48% (P=0.02). The probability of survival was slightly higher with the restrictive strategy than with the liberal strategy in the subgroup of patients who had bleeding associated with a peptic ulcer (hazard ratio, 0.70; 95% CI, 0.26 to 1.25) and was significantly higher in the subgroup of patients with cirrhosis and Child-Pugh class A or B disease (hazard ratio, 0.30; 95% CI, 0.11 to 0.85), but not in those with cirrhosis and Child-Pugh class C disease (hazard ratio, 1.04; 95% CI, 0.45 to 2.37). Within the first 5 days, the portal-pressure gradient increased significantly in patients assigned to the liberal strategy (P=0.03) but not in those assigned to the restrictive strategy.

CONCLUSIONS

As compared with a liberal transfusion strategy, a restrictive strategy significantly improved outcomes in patients with acute upper gastrointestinal bleeding. (Funded by Fundació Investigació Sant Pau; ClinicalTrials.gov number, NCT00414713.).

Medical therapies for hepatocellular carcinoma: a critical view of the evidence

The management of hepatocellular carcinoma (HCC) has substantially changed in the past few decades. Improvements in patient stratification (for example, using the Barcelona Clinic Liver Cancer staging system) and the introduction of novel therapies (such as sorafenib) have improved patient survival. Nevertheless, HCC remains the third most common cause of cancer-related deaths worldwide. Decision-making largely relies on evidence-based criteria, as depicted in the US and European clinical practice guidelines, which endorse five therapeutic recommendations: resection; transplantation; radiofrequency ablation; chemoembolization; and sorafenib. However, areas still exist in which uncertainty precludes a strong recommendation, such as the role of adjuvant therapies after resection, radioembolization with yttrium-90 or second-line therapies for advanced HCC. Many clinical trials that are currently ongoing aim to answer these questions. The first reported studies, however, failed to identify novel therapeutic alternatives (that is, sunitinib, erlotinib or brivanib). Moreover, genomic profiling has enabled patient classification on the basis of molecular parameters, and has facilitated the development of new effective drugs. However, no oncogene addiction loops have been identified so far, as has been the case with other cancers such as melanoma, lung or breast cancer. Efforts that focus on the implementation of personalized medicine approaches in HCC will probably dominate research in the next decade.

Autophagy and mesenchymal cell fibrogenesis

Autophagy is a catabolic pathway essential for cellular energy homeostasis that involves the self-degradation of intracellular components in lysosomes. This process has been implicated in the pathophysiology of many human disorders, including infection, cancer, and fibrosis. Autophagy is also recognized as a mediator of survival and proliferation, and multiple pathways induce autophagy under conditions of cellular stress, including nutrient and energy depletion. High autophagic activity has been detected in fibrogenic cells from several tissues; however the role of autophagy in fibrogenesis and mesenchymal cells varies greatly in different tissues and settings, with contributions uncovered to energy metabolism and collagen turnover by fibrogenic cells. Because several chemical modulators of autophagy have already been identified, autophagy regulation constitutes a potential target for antifibrotic therapy. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.

Genomics and proteomics in liver fibrosis and cirrhosis

Genomics and proteomics have become increasingly important in biomedical science in the past decade, as they provide an opportunity for hypothesis-free experiments that can yield major insights not previously foreseen when scientific and clinical questions are based only on hypothesis-driven approaches. Use of these tools, therefore, opens new avenues for uncovering physiological and pathological pathways. Liver fibrosis is a complex disease provoked by a range of chronic injuries to the liver, among which are viral hepatitis, (non-) alcoholic steatohepatitis and autoimmune disorders. Some chronic liver patients will never develop fibrosis or cirrhosis, whereas others rapidly progress towards cirrhosis in a few years. This variety can be caused by disease-related factors (for example, viral genotype) or host-factors (genetic/epigenetic). It is vital to establish accurate tools to identify those patients at highest risk for disease severity or progression in order to determine who are in need of immediate therapies. Moreover, there is an urgent imperative to identify non-invasive markers that can accurately distinguish mild and intermediate stages of fibrosis. Ideally, biomarkers can be used to predict disease progression and treatment response, but these studies will take many years due to the requirement for lengthy follow-up periods to assess outcomes. Current genomic and proteomic research provides many candidate biomarkers, but independent validation of these biomarkers is lacking, and reproducibility is still a key concern. Thus, great opportunities and challenges lie ahead in the field of genomics and proteomics, which, if successful, could transform the diagnosis and treatment of chronic fibrosing liver diseases.

Pathogenesis of liver fibrosis

Liver fibrosis is a major cause of morbidity and mortality worldwide due to chronic viral hepatitis and, more recently, from fatty liver disease associated with obesity. Hepatic stellate cell activation represents a critical event in fibrosis because these cells become the primary source of extracellular matrix in liver upon injury. Use of cell-culture and animal models has expanded our understanding of the mechanisms underlying stellate cell activation and has shed new light on genetic regulation, the contribution of immune signaling, and the potential reversibility of the disease. As pathways of fibrogenesis are increasingly clarified, the key challenge will be translating new advances into the development of antifibrotic therapies for patients with chronic liver disease.

Pathogenesis of liver fibrosis

Liver fibrosis is a major cause of morbidity and mortality worldwide due to chronic viral hepatitis and, more recently, from fatty liver disease associated with obesity. Hepatic stellate cell activation represents a critical event in fibrosis because these cells become the primary source of extracellular matrix in liver upon injury. Use of cell-culture and animal models has expanded our understanding of the mechanisms underlying stellate cell activation and has shed new light on genetic regulation, the contribution of immune signaling, and the potential reversibility of the disease. As pathways of fibrogenesis are increasingly clarified, the key challenge will be translating new advances into the development of antifibrotic therapies for patients with chronic liver disease.