WFUMB Guidelines/Guidance on Liver Multiparametric Ultrasound. Part 2: Guidance on Liver Fat Quantification.

The World Federation for Ultrasound in Medicine and Biology (WFUMB) has promoted the development of this document on multiparametric ultrasound. Part 2 is a guidance on the use of the available tools for the quantification of liver fat content with ultrasound. These are attenuation coefficient, backscatter coefficient, and speed of sound. All of them use the raw data of the ultrasound beam to estimate liver fat content. This guidance has the aim of helping the reader in understanding how they work and interpret the results. Confounding factors are discussed and a standardized protocol for measurement acquisition is suggested to mitigate them. The recommendations were based on published studies and experts' opinion but were not formally graded because the body of evidence remained low at the time of drafting this document.

Early Versus Standard Initiation of Terlipressin for Acute Kidney Injury in ACLF: A Randomized Controlled Trial (eTerli Study).

BACKGROUND AND AIMS: Terlipressin infusion is effective in hepatorenal syndrome (HRS-AKI). However, its efficacy for HRS-AKI resolution in acute-on-chronic liver failure (ACLF) patients has been suboptimal. Progression of AKI is rapid in ACLF. We investigated whether early initiation of terlipressin(eTerli) can improve response rates. METHODS: Consecutive ACLF patients with stage II/III AKI despite albumin resuscitation (40 g) were randomized to receive terlipressin at 2 mg/24 h plus albumin at 12 h (ET, n = 35) or at 48 h as standard therapy (ST, n = 35). (June 22, 2020 to June 10, 2022). The primary end-point was AKI reversal by day7. RESULTS: Baseline parameters including AKI stage and ACLF-AARC scores in two arms were comparable. Full AKI response at day 7 was higher in ET [24/35 (68.6%)] than ST arm [11/35 (31.4%; P 0.03]. Day3 AKI response was also higher in ET arm [11/35 (31.4%) vs. 4/35 (11.4%), P 0.04]. Using ST compared to ET [HR 4.3; P 0.026] and day 3 serum creatinine > 1.6 mg/dl [HR 9.1; AUROC-0.866; P < 0.001] predicted HRS-AKI non-response at day 7. ET patients showed greater improvement in ACLF grade, mean arterial pressure, and urine output at day 3, and required lower albumin within 7 days than ET arm (149.1 ± 41.8 g vs. 177.5 ± 40.3 g, P 0.006) and had lower 28-day mortality: 40% vs. 65.7%, P 0.031]. Early use of terlipressin than ST [HR 2.079; P 0.038], baseline HE [HR 2.929; P 0.018], and AKI persistence at day 3 [HR 1.369; P 0.011] predicted 28-day mortality. Fifteen (21.4%) patients had treatment related adverse effects, none was life threatening. CONCLUSION: In ACLF patients, early initiation of terlipressin for AKI persisting after 12 h of volume expansion with albumin helps in reduced short-term mortality and early AKI reversal with regression of ACLF stage. These results indicate need for change in current practice for terlipressin usage in HRS-AKI.

Furanocoumarins promote proteasomal degradation of viral HBx protein and down-regulate cccDNA transcription and replication of hepatitis B virus.

Nucleot(s)ide analogues, the current antiviral treatments against chronic hepatitis B (CHB) infection, are non-curative due to their inability to eliminate covalently closed circular DNA (cccDNA) from the infected hepatocytes. Preclinical studies have shown that coumarin derivatives can effectively reduce the HBV DNA replication. We evaluated the antiviral efficacy of thirty new coumarin derivatives in cell culture models for studying HBV. Furanocoumarins Fc-20 and Fc-31 suppressed the levels of pre-genomic RNA as well as cccDNA, and reduced the secretion of virions, HBsAg and HBeAg. The antiviral efficacies of Fc-20 and Fc31 improved further when used in combination with the hepatitis B antiviral drug Entecavir. There was a marked reduction in the intracellular HBx level in the presence of these furanocoumarins due to proteasomal degradation resulting in the down-regulation of HBx-dependent viral genes. Importantly, both Fc-20 and Fc-31 were non-cytotoxic to cells even at high concentrations. Further, our molecular docking studies confirmed a moderate to high affinity interaction between furanocoumarins and viral HBx via residues Ala3, Arg26 and Lys140. These data suggest that furanocoumarins could be developed as a new therapeutic for CHB infection.

APASL clinical practice guidelines on the management of acute kidney injury in acute-on-chronic liver failure.

Acute-on-chronic liver failure (ACLF) is a syndrome that is characterized by the rapid development of organ failures predisposing these patients to a high risk of short-term early death. The main causes of organ failure in these patients are bacterial infections and systemic inflammation, both of which can be severe. For the majority of these patients, a prompt liver transplant is still the only effective course of treatment. Kidneys are one of the most frequent extrahepatic organs that are affected in patients with ACLF, since acute kidney injury (AKI) is reported in 22.8-34% of patients with ACLF. Approach and management of kidney injury could improve overall outcomes in these patients. Importantly, patients with ACLF more frequently have stage 3 AKI with a low rate of response to the current treatment modalities. The objective of the present position paper is to critically review and analyze the published data on AKI in ACLF, evolve a consensus, and provide recommendations for early diagnosis, pathophysiology, prevention, and management of AKI in patients with ACLF. In the absence of direct evidence, we propose expert opinions for guidance in managing AKI in this very challenging group of patients and focus on areas of future research. This consensus will be of major importance to all hepatologists, liver transplant surgeons, and intensivists across the globe.

Dynamic Assessment of Modified Quick Sequential Organ Failure Assessment in Acutely Deteriorated Patients with Chronic Liver Disease.

Background/Aims: Quick sequential organ failure assessment (qSOFA) has been suggested to identify those who have poor outcomes in patients with suspected infection. We aimed to evaluate the ability of the modified qSOFA (m-qSOFA) to identify high-risk patients in acutely deteriorated patients with chronic liver disease (CLD), especially acute-on-chronic liver failure (ACLF). Methods: We used the data of both Korean Acute-on-Chronic Liver Failure (KACLiF) and Asian Pacific Association for the Study of the Liver ACLF Research Consortium (AARC) cohorts. qSOFA was modified by replacing the Glasgow Coma Scale with hepatic encephalopathy, and m-qSOFA≥2 was considered high. Results: Patients with high m-qSOFA had a significantly lower 1-month transplant-free survival (TFS) in both cohorts and higher organ failure development in KACLiF than patients with low m-qSOFA (Ps<0.05). Subgroup analysis by ACLF showed that patients with high m-qSOFA had lower TFS than patients with low m-qSOFA. m-qSOFA was an independent prognostic factor (hazard ratios (HR)=2.604, 95% confidence interval (CI) 1.353-5.013, P=0.004 in KACLiF and HR=1.904, 95% CI 1.484-2.442, P<0.001 in AARC). The patients with low m-qSOFA at baseline but high m-qSOFA on the 7th day had a significantly lower 1-month TFS than the patients with high m-qSOFA at baseline but low m-qSOFA on the 7th day (52.6% vs. 89.4%, P<0.001 in KACLiF and 26.9% vs. 61.5%, P<0.001 in AARC). Conclusion: Baseline and dynamic changes in m-qSOFA were useful to identify patients with a high risk of organ failure development and short-term mortality among CLD patients with acute deterioration.

Acute-on-chronic liver failure - steps towards harmonization of the definition!

Acute-on-chronic liver failure (ACLF), usually precipitated by alcohol misuse or viral reactivation, is characterised by rapid onset and usually reversible liver failure. Various definitions of ACLF have been proposed and widely used across the globe, including those by APASL, COSSH, EASL-CLIF, Japanese experts, and NACSELD. Although all the definitions have several similarities and connote high short-term mortality, a clear and standardised definition is still lacking, hampering research in this key area. In this review, we discuss the similarities and differences among various definitions and propose steps to harmonise EASL-CLIF, APASL, NACSELD, Japanese, and Chinese definitions of ACLF.

Rapid Electrochemical Detection of Bacterial Sepsis in Cirrhotic Patients: A Microscaffold-Based Approach for Early Intervention.

Sepsis is a dysregulated inflammatory response leading to multiple organ failure. Current methods of sepsis detection are time-consuming, involving nonspecific clinical signs, biomarkers, and blood cultures. Hence, efficient and rapid sepsis detection platforms are of utmost need for immediate antibiotic treatment. In the current study, a noninvasive rapid monitoring electrochemical sensing (ECS) platform was developed for the detection and classification of plasma samples of patients with liver cirrhosis by measuring the current peak shifts using the cyclic voltammetry (CV) technique. A total of 61 hospitalized cirrhotic patients with confirmed (culture-positive) or suspected (culture-negative) sepsis were enrolled. The presence of bacteria in the plasma was observed by growth kinetics, and for rapidness, the samples were co-encapsulated in microscaffolds with carbon nanodots that were sensitive enough to detect redox changes occurring due to the change in the pH of the surrounding medium, causing shifts in current peaks in the voltammograms within 2 h. The percentage area under the curve for confirmed infections was 94 and that with suspected cases was 87 in comparison to 69 and 71 with PCT, respectively. Furthermore, the charge was measured for class identification. The charge for LPS-absent bacteria ranged from -400 to -600 µC, whereas the charge for LPS-containing bacteria class ranged from -290 to -300 µC. Thus, the developed cost-effective system was sensitive enough to detect and identify bacterial sepsis.

Transjugular Intrahepatic Portosystemic Shunt (TIPS) Extension for Transhepatic Mesocaval Shunt Creation: A Case Series for Treating Refractory Upper Gastrointestinal Bleeding in Patients with Chronic Portal Vein Thrombosis.

Transjugular intrahepatic portosystemic shunt (TIPS) is known to benefit patients with decompensated liver disease by alleviating portal pressure. However, TIPS creation is technically difficult and challenging to perform in patients with chronic portal vein thrombosis (PVT) (4,5). Multiple endovascular techniques for portal vein recanalization with or without creating portosystemic shunt are available to decompress and alleviate portal hypertension in patients with PVT. In this case series, we represent TIPS extension to create an endovascular mesocaval shunt for the treatment of refractory upper gastrointestinal bleeding.

Ammonia is associated with liver-related complications and predicts mortality in acute-on-chronic liver failure patients.

The relationship between ammonia and liver-related complications (LRCs) in acute-on-chronic liver failure (ACLF) patients is not clearly established. This study aimed to evaluate the association between ammonia levels and LRCs in patients with ACLF. The study also evaluated the ability of ammonia in predicting mortality and progression of LRCs. The study prospectively recruited ACLF patients based on the APASL definition from the ACLF Research Consortium (AARC) from 2009 to 2019. LRCs were a composite endpoint of bacterial infection, overt hepatic encephalopathy (HE), and ascites. A total of 3871 cases were screened. Of these, 701 ACLF patients were enrolled. Patients with LRCs had significantly higher ammonia levels than those without. Ammonia was significantly higher in patients with overt HE and ascites, but not in those with bacterial infection. Multivariate analysis found that ammonia was associated with LRCs. Additionally, baseline arterial ammonia was an independent predictor of 30-day mortality, but it was not associated with the development of new LRCs within 30 days. In summary, baseline arterial ammonia levels are associated with 30-day mortality and LRCs, mainly overt HE and ascites in ACLF patients.

Comparative metabolome analysis reveals higher potential of haemoperfusion adsorption in providing favourable outcome in ACLF patients.

BACKGROUND AND AIMS: Acute-on-chronic liver failure (ACLF) is a serious illness associated with altered metabolome, organ failure and high mortality. Need for therapies to improve the metabolic milieu and support liver regeneration are urgently needed. METHODS: We investigated the ability of haemoperfusion adsorption (HA) and therapeutic plasma exchange (TPE) in improving the metabolic profile and survival in ACLF patients. Altogether, 45 ACLF patients were randomized into three groups: standard medical therapy (SMT), HA and TPE groups. Plasma metabolomics was performed at baseline, post-HA and TPE sessions on days 7 and 14 using high-resolution mass spectrometry. RESULTS: The baseline clinical/metabolic profiles of study groups were comparable. We identified 477 metabolites. Of these, 256 metabolites were significantly altered post 7 days of HA therapy (p < .05, FC > 1.5) and significantly reduced metabolites linked to purine (12 metabolites), tryptophan (7 metabolites), primary bile acid (6 metabolites) and arginine-proline metabolism (6 metabolites) and microbial metabolism respectively (p < .05). Metabolites linked to taurine-hypotaurine and histidine metabolism were reduced and temporal increase in metabolites linked to phenylalanine and tryptophan metabolism was observed post-TPE therapy (p < .05). Finally, weighted metabolite correlation network analysis (WMCNA) along with inter/intragroup analysis confirmed significant reduction in inflammatory (tryptophan, arachidonic acid and bile acid metabolism) and secondary energy metabolic pathways post-HA therapy compared to TPE and SMT (p < .05). Higher baseline plasma level of 11-deoxycorticosterone (C03205; AUROC > 0.90, HR > 3.2) correlated with severity (r2 > 0.5, p < .05) and mortality (log-rank-p < .05). Notably, 51 of the 64 metabolite signatures (ACLF non-survivor) were reversed post-HA treatment compared to TPE and SMT(p < .05). CONCLUSION: HA more potentially (~80%) improves plasma milieu compared to TPE and SMT. High baseline plasma 11-deoxycorticosterone level correlates with early mortality in ACLF patients.

Liver volumetry in cirrhotic patients with or without hepatocellular carcinoma: Its correlation with Child-Pugh, model for end-stage liver diseases and indocyanine green dye test.

BACKGROUND AND OBJECTIVES: To evaluate the correlation between non-tumoral liver volume (NTLV) by computed tomography (CT) volumetry and indocyanine green retention at 15 minutes (ICG-r15%), Child-Pugh score (CTP) and model for end-stage liver diseases (MELD) score in cirrhotic patients having hepatocellular carcinoma (HCC) (group A) and in cirrhotics without HCC (group B). METHODS: As many as 111 consecutive patients with liver cirrhosis, who underwent triple-phase CT abdomen, were retrospectively included in our study. They were classified into group A (cirrhosis with HCC, n = 69) and group B (cirrhosis only, n = 42). Segmental liver volume, tumor and NTLV were calculated using Myrian XP-Liver segmentation software. In group B, NTLV was the same as the total liver volume (TLV). The correlation of NTLV with ICG-r15%, CTP and MELD scores was analyzed using appropriate correlation tests for each group. RESULTS: NTLV had a good and significant negative correlation with ICG-r15% (ρ = - 512; p < 0.001) in group A, but not in group B. It also had a significant negative correlation with CTP (ρ = - 251; p = 0.038) and MELD (ρ = - 323; p = 0.007) scores only in group A. Furthermore, ICG-r15% had a good and significant positive correlation with CTP and MELD scores in both groups (p < 0.05). CONCLUSION: NTLV showed a significant negative correlation with ICG-r15% in cirrhotic patients with HCC, but not in cirrhotic patients without HCC. Therefore, CT volumetry can be a valuable tool to predict the functional hepatic volume in patients of cirrhosis with HCC subjected for hepatectomy, where a facility of ICG-r15% is not available. However, further studies are needed to validate our findings in cirrhotic only patients.

High prevalence of MAFLD in general population: A large cross-sectional study calls for concerted public health action.

BACKGROUND: Metabolic associated fatty liver disease (MAFLD) is a relatively new term with limited studies done in South Asian population. AIM: To determine prevalence and clinico-epidemiological characteristics of MAFLD in general population. METHODS: A cross-sectional study was conducted in randomly selected regions across Delhi, India. Data were collected on socio-demographic particulars, health status and lifestyle factors. Anthropometric measurements, transient elastography, and laboratory investigations were carried out. RESULTS: Altogether 6146 participants (mean age: 43.1 ± 13.9 years, 48.1% males) were included. The prevalence of MAFLD was 56.4% (n = 3468), of which lean MAFLD constituted 11.3%. Higher age (OR: 2.47; 95% CI: 2.21-2.76), low education level (OR: 1.23; 95% CI: 1.09-1.39), upper socio-economic class (OR: 1.32; 95% CI: 1.17-1.49), and low physical activity (OR: 1.15; 95% CI: 1.03-1.28) were more common in MAFLD. The association of female sex with MAFLD differed in age groups <40 years (OR: 0.64 and 95% CI: 0.55-0.75) and >40 years (OR: 1.40 and 95% CI: 1.22-1.62) in both magnitude and direction (p < 0.001). Liver fibrosis was present in 23% of the study population (32.2% among MAFLD group). Advanced liver fibrosis was three times more common in MAFLD group (6.2% vs 1.8%, p < 0.001). Obesity and fibrosis had a statistically significant relationship and 75.8% of the individuals with advanced stages of fibrosis had obesity. CONCLUSION: Nearly half of study population was found to have MAFLD. Advanced hepatic fibrosis was three times more common in these subjects. Aggressive public health measures are urgently required to raise awareness and introduce interventional strategies.

Asian Pacific Association for the Study of the Liver clinical practice guidelines on liver transplantation.

Liver transplantation is a highly complex and challenging field of clinical practice. Although it was originally developed in western countries, it has been further advanced in Asian countries through the use of living donor liver transplantation. This method of transplantation is the only available option in many countries in the Asia-Pacific region due to the lack of deceased organ donation. As a result of this clinical situation, there is a growing need for guidelines that are specific to the Asia-Pacific region. These guidelines provide comprehensive recommendations for evidence-based management throughout the entire process of liver transplantation, covering both deceased and living donor liver transplantation. In addition, the development of these guidelines has been a collaborative effort between medical professionals from various countries in the region. This has allowed for the inclusion of diverse perspectives and experiences, leading to a more comprehensive and effective set of guidelines.

Dissociation in hepatic vein pressure gradient, liver stiffness measurement and complications in histological subtypes of porto-sinusoidal vascular disease.

BACKGROUND AND AIMS: Portosinusoidal vascular disease (PSVD) is a broad term encompassing varied histological patterns with changes in portal tracts and sinusoids without cirrhosis. We aimed to assess whether there is any clinical and pathological difference among the various histological categories of PSVD. PATIENTS AND METHODS: This study included liver biopsy cases classified as PSVD (2020-2022). Clinical and laboratory parameters were obtained from the electronic records. PSVD cases were histologically categorised as obliterative portal venopathy (OPV), OPV with fibrosis (OPV-F), incomplete septal cirrhosis (ISC), nodular regenerative hyperplasia (NRH), mega sinusoids with fibrosis (MSF) and unclassified. Follow-up complications were recorded. RESULTS: PSVD categories were OPV (45 (26%)), OPV-F (37 (21.4%)), ISC (20 (11.6%)), NRH (19 (11%)), MSF (19 (11%)) and unclassified (33 (19%)). Elevated hepatic venous pressure gradient (HVPG) was noted in OPV-F (10 (IQR: 12-14.7)) and ISC (12 (IQR: 9-14)) mm Hg with higher fibrosis quantity in liver tissue and elevated procollagen III aminoterminal propeptide, which correlated with HVPG. On immunohistochemistry, OPV-F and ISC showed lesser expression of ADAMT13 in liver biopsies (p<0.001). On follow-up, ascites development was more in OPV-F and ISC than in other categories (p=0.001). Higher liver stiffness measurement (LSM) values were recorded in MSF and NRH, compared with other categories, but it did not correlate with fibrosis in liver biopsy. CONCLUSIONS: OPV-F and ISC had higher HVPG, fibrosis, and more ascites development on follow-up than the other categories of PSVD, and all are not the same. In contrast, MSF and NRH have spuriously high LSM.

A global action agenda for turning the tide on fatty liver disease.

BACKGROUND AND AIMS: Fatty liver disease is a major public health threat due to its very high prevalence and related morbidity and mortality. Focused and dedicated interventions are urgently needed to target disease prevention, treatment, and care. APPROACH AND RESULTS: We developed an aligned, prioritized action agenda for the global fatty liver disease community of practice. Following a Delphi methodology over 2 rounds, a large panel (R1 n = 344, R2 n = 288) reviewed the action priorities using Qualtrics XM, indicating agreement using a 4-point Likert-scale and providing written feedback. Priorities were revised between rounds, and in R2, panelists also ranked the priorities within 6 domains: epidemiology, treatment and care, models of care, education and awareness, patient and community perspectives, and leadership and public health policy. The consensus fatty liver disease action agenda encompasses 29 priorities. In R2, the mean percentage of "agree" responses was 82.4%, with all individual priorities having at least a super-majority of agreement (> 66.7% "agree"). The highest-ranked action priorities included collaboration between liver specialists and primary care doctors on early diagnosis, action to address the needs of people living with multiple morbidities, and the incorporation of fatty liver disease into relevant non-communicable disease strategies and guidance. CONCLUSIONS: This consensus-driven multidisciplinary fatty liver disease action agenda developed by care providers, clinical researchers, and public health and policy experts provides a path to reduce the prevalence of fatty liver disease and improve health outcomes. To implement this agenda, concerted efforts will be needed at the global, regional, and national levels.

Determinants of clinical response to empirical antibiotic treatment in patients with cirrhosis and bacterial and fungal infections-Results from the ICA "Global Study" (EABCIR-Global Study).

BACKGROUND: The administration of an appropriate empirical antibiotic treatment is essential in cirrhosis and severe bacterial infections. We aimed to investigate the predictors of clinical response of empirical antibiotic treatment in a prospective cohort of patients with cirrhosis and bacterial and fungal infections included in the International Club of Ascites "Global Study." METHODS: Patients hospitalized with cirrhosis and bacterial/fungal infection were prospectively enrolled at 46 centers. Clinical response to antibiotic treatment was defined according to changes in markers of infection/inflammation, vital signs, improvement of organ failure, and results of cultures. RESULTS: From October 2015 to September 2016, 1302 patients were included at 46 centers. A clinical response was achieved in only 61% of cases. Independent predictors of lack of clinical response to empirical treatment were C-reactive protein (OR = 1.16; 95% CI = 1.02-1.31), blood leukocyte count (OR = 1.39;95% CI = 1.09-1.77), serum albumin (OR = 0.70; 95% CI = 0.55-0.88), nosocomial infections (OR = 1.96; 95% CI = 1.20-2.38), pneumonia (OR = 1.75; 95% CI = 1.22-2.53), and ineffective treatment according to antibiotic susceptibility test (OR = 5.32; 95% CI = 3.47-8.57). Patients with a lack of clinical response to first-line antibiotic treatment had a significantly lower resolution rate of infections (55% vs. 96%; p < 0.001), a higher incidence of second infections (29% vs. 15%; p < 0.001), shock (35% vs. 7%; p < 0.001) and new organ failures (52% vs. 19 %; p < 0.001) than responders. Clinical response to empirical treatment was an independent predictor of 28-day survival ( subdistribution = 0.20; 95% CI = 0.14-0.27). CONCLUSIONS: Four out of 10 patients with cirrhosis do not respond to the first-line antibiotic therapy, leading to lower resolution of infections and higher mortality. Broader-spectrum antibiotics and strategies targeting systemic inflammation may improve prognosis in patients with a high degree of inflammation, low serum albumin levels, and severe liver impairment.

Comparison of Balloon-Occluded Thrombolysis with Catheter-Directed Thrombolysis in Patients of Budd-Chiari Syndrome with Occluded Direct Intrahepatic Portosystemic Shunt.

Objectives Direct intrahepatic portosystemic shunt (DIPS) stent placement is an effective treatment for patients with Budd-Chiari syndrome (BCS); however, thrombotic occlusion of DIPS stent remains a cause of concern. The purpose of this study is to describe a novel technique of balloon-occluded-thrombolysis (BOT) for occluded DIPS stent, and compare it with the conventional catheter-directed-thrombolysis (CDT). Methods In this retrospective study, the hospital database was searched for BCS patients who underwent DIPS revision for thrombotic stent occlusion between January 2015 and February 2021. Patients were divided into CDT group and BOT group. The groups were compared for technical success, total dose of thrombolytic agent administered, duration of hospital stay, and primary assisted stent patency rates at 1- and 6-month follow-up. Results CDT was performed in 12 patients, whereas 21 patients underwent BOT. Complete recanalization was achieved in 66.7% (8 of 12) patients of CDT group as compared to 81% (17 of 21) patients of BOT group (nonsignificant difference, p = 0.420). BOT group had a short hospital stay (1.8 ± 0.7 vs. 3.5 ± 1.0 days) and required less dose of thrombolytic agent ([2.2 ± 0.4]x10 5 IU versus [8.3 ± 2.9]x10 5 IU of urokinase) as compared to the CDT group and both differences were statistically significant ( p < 0.001). Further, 6-month patency rate was higher in BOT group as compared to CDT group ( p = 0.024). Conclusion The novel BOT technique of DIPS revision allows longer contact time of thrombolytic agent with the thrombi within the occluded stent. This helps in achieving fast recanalization of thrombosed DIPS stent with a significantly less dose of thrombolytic agent required, thus reducing the risk of systemic complications associated with thrombolytic administration.

Targeted HBx gene editing by CRISPR/Cas9 system effectively reduces epithelial to mesenchymal transition and HBV replication in hepatoma cells.

BACKGROUND AND AIMS: Hepatitis B virus X protein (HBx) play a key role in pathogenesis of HBV-induced hepatocellular carcinoma (HCC) by promoting epithelial to mesenchymal transition (EMT). In this study, we hypothesized that inhibition of HBx is an effective strategy to combat HCC. METHODOLOGY AND RESULTS: We designed and synthesized novel HBx gene specific single guide RNA (sgRNA) with CRISPR/Cas9 system and studied its in vitro effects on tumour properties of HepG2-2.15. Full length HBx gene was excised using HBx-CRISPR that resulted in significant knockdown of HBx expression in hepatoma cells. HBx-CRISPR also decreased levels of HBsAg and HBV cccDNA expression. A decreased expression of mesenchymal markers, proliferation and tumorigenic properties was observed in HBx-CRISPR treated cells as compared to controls in both two- and three- dimensional (2D and 3D) tumour models. Transcriptomics data showed that out of 1159 differentially expressed genes in HBx-CRISPR transfected cells as compared to controls, 70 genes were upregulated while 1089 genes associated with cell proliferation and EMT pathways were downregulated. CONCLUSION: Thus, targeting of HBx by CRISPR/Cas9 gene editing system reduces covalently closed circular DNA (cccDNA) levels, HBsAg production and mesenchymal characteristics of HBV-HCC cells. We envision inhibition of HBx by CRISPR as a novel therapeutic approach for HBV-induced HCC.