Acute cytomegalovirus infection modulates the intestinal microbiota and targets intestinal epithelial cells.

Primary and recurrent cytomegalovirus (CMV) infections frequently cause CMV colitis in immunocompromised as well as inflammatory bowel disease (IBD) patients. Additionally, colitis occasionally occurs upon primary CMV infection in patients who are apparently immunocompetent. In both cases, the underlying pathophysiologic mechanisms are largely elusive - in part due to the lack of adequate access to specimens. We employed the mouse cytomegalovirus (MCMV) model to assess the association between CMV and colitis. During acute primary MCMV infection of immunocompetent mice, the gut microbial composition was affected as manifested by an altered ratio of the Firmicutes to Bacteroidetes phyla. Interestingly, these microbial changes coincided with high-titer MCMV replication in the colon, crypt hyperplasia, increased colonic pro-inflammatory cytokine levels, and a transient increase in the expression of the antimicrobial protein Regenerating islet-derived protein 3 gamma (Reg3γ). Further analyses revealed that murine and human intestinal epithelial cell lines, as well as primary intestinal crypt cells and organoids represent direct targets of CMV infection causing increased cell death. Accordingly, in vivo MCMV infection disrupted the intestinal epithelial barrier and increased apoptosis of intestinal epithelial cells. In summary, our data show that CMV transiently induces colitis in immunocompetent hosts by altering the intestinal homeostasis.

Thyroid hormone receptor alpha modulates fibrogenesis in hepatic stellate cells.

OBJECTIVE: Progressive hepatic fibrosis can be considered the final stage of chronic liver disease. Hepatic stellate cells (HSC) play a central role in liver fibrogenesis. Thyroid hormones (TH, e.g. thyroxine; T4 and triiodothyronine; T3) significantly affect development, growth, cell differentiation and metabolism through activation of TH receptor α and/or ß (TRα/ß). Here, we evaluated the influence of TH in hepatic fibrogenesis. DESIGN: Human liver tissue was obtained from explanted livers following transplantation. TRα-deficient (TRα-KO) and wild-type (WT) mice were fed a control or a profibrogenic methionine-choline deficient (MCD) diet. Liver tissue was assessed by qRT-PCR for fibrogenic gene expression. In vitro, HSC were treated with TGFß in the presence or absence of T3. HSC with stable TRα knockdown and TRα deficient mouse embryonic fibroblasts (MEF) were used to determine receptor-specific function. Activation of HSC and MEF was assessed using the wound healing assay, Western blotting, and qRT-PCR. RESULTS: TRα and TRß expression is downregulated in the liver during hepatic fibrogenesis in humans and mice. TRα represents the dominant isoform in HSC. In vitro, T3 blunted TGFß-induced expression of fibrogenic genes in HSC and abrogated wound healing by modulating TGFß signalling, which depended on TRα presence. In vivo, TRα-KO enhanced MCD diet-induced liver fibrogenesis. CONCLUSION: These observations indicate that TH action in non-parenchymal cells is highly relevant. The interaction of TRα with TH regulates the phenotype of HSC via the TGFß signalling pathway. Thus, the TH-TR axis may be a valuable target for future therapy of liver fibrosis.

Pathological neutrophil migration predicts adverse outcomes in hospitalized patients with liver cirrhosis.

BACKGROUND AND AIMS: Given the early response of neutrophil granulocytes to infections, detection of pathological neutrophil migration might help in predicting adverse events in patients with liver cirrhosis. METHODS: Migration of blood neutrophils in hospitalized patients with cirrhosis was characterized by a novel standardized migration assay. Pathological neutrophil migration patterns were associated with a composite endpoint of ACLF, sepsis or death within 7 or 30 days. RESULTS: Overall, 125 patients were included, of whom 11 (8.8%) had compensated cirrhosis, 84 (67.2%) had acute decompensation (AD) and 30 (24%) had acute-on-chronic liver failure (ACLF). The migration response of neutrophils from patients with AD or ACLF to stimulation with the chemotactic formylpeptide f-Met-Leu-Phe (fMLP) was significantly impaired, while the response to chemokine (C-X-C motif)-ligand 8 (CXCL8) was affected less pronouncedly. In contrast, no relevant differences in response to CXCL1 were observed. Of note, neutrophils of a number of patients with AD and ACLF were largely immotile at resting and stimulated conditions. Patients with non-migrating neutrophils at unstimulated conditions were at high risk to develop the composite endpoint of ACLF, sepsis or death. Moreover, expression of chemokine receptors CXCR1 and CXCR2 was significantly decreased in patients with ACLF. Interestingly, the expression of chemokine receptors did not correlate with neutrophil migration patterns, but-based on the increased expression of the cell surface markers CD66b and CD177-neutrophils of patients with AD and ACLF were strongly pre-activated. CONCLUSION: Pathological neutrophil migration in patients with cirrhosis indicates a high risk of developing adverse outcomes.

Limited access to liver transplantation and TIPS despite high mortality, healthcare resource use and costs of cirrhosis in Germany.

BACKGROUND AND AIMS: Data on number of patients with cirrhosis in Germany are limited. We therefore aimed to estimate prevalence, comorbidities, mortality, utilization of healthcare resources and costs of patients with cirrhosis and incidence of decompensation of cirrhosis in Germany. METHODS: This longitudinal observational study was based on an anonymized representative claims database including 4.9 million persons insured by a statutory health insurance (SHI) between 2015-2020. Patients with decompensated and compensated cirrhosis were selected via diagnostic ICD codes and followed for 2 years. RESULTS: Prevalence of cirrhosis in 2015 was 250/100 000, resulting in 201 747 (95% CI: 197 540-206 040) patients extrapolated to the German population. Out of all patients with compensated cirrhosis in 2015 who did not deceased, 16.0% developed a decompensation within 3 years. Overall, 978 patients (Ø-age: 68 years; 60% male) were included in the decompensated, and 5135 patients (Ø-age: 66 years; 59% male) in the compensated cirrhosis cohort. Patients with decompensated cirrhosis had a higher burden of comorbidities (Charlson Comorbidity Index 7.3 vs. 4.4) and 3 times higher costs per quarter (7172 € vs. 2213 €) than patients with compensated cirrhosis. 1-year mortality after decompensation was 51% compared to 8% in compensated cirrhosis. Of note, only few patients with decompensated cirrhosis received a liver transplantation or transjugular intrahepatic portosystemic shunts (TIPS) (1% and 5%). CONCLUSION: Patients with cirrhosis have a high healthcare burden in especially decompensated stage. Accordingly, 1-year mortality of decompensated cirrhosis in Germany is high. Despite high health resource utilization, only few patients have access to liver transplantation or TIPS.

Nuclear translocation of YAP drives BMI-associated hepatocarcinogenesis in hepatitis B virus infection.

BACKGROUND AND AIMS: Hepatitis B virus (HBV) infection is a major cause of hepatocellular carcinoma (HCC) development and progression. The aim of this study was to mechanistically investigate the involvement of Hippo signalling in HBV surface antigen (HBsAg)-dependent neoplastic transformation. METHODS: Liver tissue and hepatocytes from HBsAg-transgenic mice were examined for the Hippo cascade and proliferative events. Functional experiments in mouse hepatoma cells included knockdown, overexpression, luciferase reporter assays and chromatin immunoprecipitation. Results were validated in HBV-related HCC biopsies. RESULTS: Hepatic expression signatures in HBsAg-transgenic mice correlated with YAP responses, cell cycle control, DNA damage and spindle events. Polyploidy and aneuploidy occurred in HBsAg-transgenic hepatocytes. Suppression and inactivation of MST1/2 led to the loss of YAP phosphorylation and the induction of BMI1 expression in vivo and in vitro. Increased BMI1 directly mediated cell proliferation associated with decreased level of p16INK4a , p19ARF , p53 and Caspase 3 as well as increased Cyclin D1 and γ-H2AX expression. Chromatin immunoprecipitation and the analysis of mutated binding sites in dual-luciferase reporter assays confirmed that the YAP/TEAD4 transcription factor complex bound and activated the Bmi1 promoter. In chronic hepatitis B patients, paired liver biopsies of non-tumour and tumour tissue indicated a correlation between YAP expression and the abundance of BMI1. In a proof-of-concept, treatment of HBsAg-transgenic mice with YAP inhibitor verteporfin directly suppressed the BMI1-related cell cycle. CONCLUSION: HBV-associated proliferative HCC might be related to the HBsAg-YAP-BMI1 axis and offer a potential target for the development of new therapeutic approaches.

Regional transplant rates depend more on physician-dependent variables than on proximity to transplant center.

PURPOSE: The objective of this work was to uncover inequalities in access to liver transplantation in Bavaria, Germany. METHODS: For this purpose, the annual transplantation rate per 1 million inhabitants for the respective districts was determined from the aggregated postal codes of the place of residence of transplanted patients. The variables examined were proximity and travel time to the nearest transplant center, as well as the care category of the regional hospital. In addition, we assessed whether the head of gastroenterology at the regional hospital through which liver transplant candidates are referred was trained at a liver transplant center. RESULTS: We could not demonstrate a direct relationship between proximity or travel time to the nearest transplant center and access to liver transplantation. Multivariate regression analysis shows that liver transplant training (p < 0.0001) of the chief physician (gastroenterologist) of the regional hospital was the most decisive independent factor for access to liver transplantation within a district. CONCLUSION: We show that the transplant training experience of the head of gastroenterology at a regional hospital is an independent factor for the regional transplantation rate. Therefore, it appears important to maintain some liver transplant expertise outside the transplant centers in order to properly identify and assign potential transplant candidates for transplantation.

[Use of Thrombopoetin-Receptor-Agonists (TPO-RA) in patients with liver cirrhosis before invasive procedures]. / Einsatz von Thrombopoetin-Rezeptor-Agonisten (TPO-RA) vor invasiven Eingriffen bei Patienten mit Leberzirrhose.

Advanced chronic liver disease is accompanied with relevant changes in the corpuscular and plasmatic coagulation system. Due to thrombocytopenia that is regularly observed in these patients, platelet transfusions are often performed prior invasive procedures to prevent possible bleeding complications. However, platelet transfusions are associated with clinically significant adverse events and economically relevant health care costs. Thus, avoiding unnecessary platelet transfusions remains pivotal in daily clinical practice. The first step is to carefully check if increasing platelet counts prior to a planned invasive procedure is really necessary. Nowadays, two well-tolerated thrombopoetin-receptor agonists (TPO-RAs), Avatrombopaq and Lusutrombopaq, to treat thrombocytopenia preemptively before an invasive procedure in patients with liver cirrhosis are available. This review provides a guide for clinician when to increase platelet counts prior an invasive procedure in patients with liver cirrhosis and helps to identify situations in which the use of TPO-RA may be reasonable.

Uptake of Functional Ultrasmall Gold Nanoparticles in 3D Gut Cell Models.

Ultrasmall gold nanoparticles (2 nm) easily penetrate the membranes of intestinal murine epithelial cells (MODE-K) and colorectal cancer cells (CT-26). They are also taken up by 3D spheroids (400 µm) of these cell types and primary gut organoids (500 µm). In contrast, dissolved dyes are not taken up by any of these cells or 3D structures. The distribution of fluorescent ultrasmall gold nanoparticles inside cells, spheroids, and gut organoids is examined by confocal laser scanning microscopy. Nanoparticles conjugated with the cytostatic drug doxorubicin and a fluorescent dye exhibit significantly greater cytotoxicity toward CT-26 tumor spheroids than equally concentrated dissolved doxorubicin, probably because they enter the interior of a spheroid much more easily than dissolved doxorubicin. Comprehensive analyses show that the cellular uptake of ultrasmall gold nanoparticles occurs by different endocytosis pathways.

Atezolizumab and bevacizumab with transarterial chemoembolization in hepatocellular carcinoma: the DEMAND trial protocol.

The combination of the anti-PD-L1 antibody atezolizumab and the anti-VEGF bevacizumab is the first approved immunotherapeutic regimen for first-line therapy in patients with unresectable hepatocellular carcinoma (HCC), currently approved in more than 80 countries. The efficacy and tolerability of this regimen suggest that the use of atezolizumab + bevacizumab could be extended to the treatment of patients with intermediate-stage HCC in combination with transarterial chemoembolization (TACE). The authors describe the rationale and design of the DEMAND study. This investigator-initiated, multicenter, randomized phase II study is the first trial to evaluate the safety and efficacy of atezolizumab + bevacizumab prior to or in combination with TACE in patients with intermediate-stage HCC. The primary end point is the 24-month survival rate; secondary end points include objective response rate, progression-free survival, safety and quality of life. Clinical Trial Registration: NCT04224636 (ClinicalTrials.gov).

Extended interaction networks with HCV protease NS3-4A substrates explain the lack of adaptive capability against protease inhibitors.

Inhibitors against the NS3-4A protease of hepatitis C virus (HCV) have proven to be useful drugs in the treatment of HCV infection. Although variants have been identified with mutations that confer resistance to these inhibitors, the mutations do not restore replicative fitness and no secondary mutations that rescue fitness have been found. To gain insight into the molecular mechanisms underlying the lack of fitness compensation, we screened known resistance mutations in infectious HCV cell culture with different genomic backgrounds. We observed that the Q41R mutation of NS3-4A efficiently rescues the replicative fitness in cell culture for virus variants containing mutations at NS3-Asp168 To understand how the Q41R mutation rescues activity, we performed protease activity assays complemented by molecular dynamics simulations, which showed that protease-peptide interactions far outside the targeted peptide cleavage sites mediate substrate recognition by NS3-4A and support protease cleavage kinetics. These interactions shed new light on the mechanisms by which NS3-4A cleaves its substrates, viral polyproteins and a prime cellular antiviral adaptor protein, the mitochondrial antiviral signaling protein MAVS. Peptide binding is mediated by an extended hydrogen-bond network in NS3-4A that was effectively optimized for protease-MAVS binding in Asp168 variants with rescued replicative fitness from NS3-Q41R. In the protease harboring NS3-Q41R, the N-terminal cleavage products of MAVS retained high affinity to the active site, rendering the protease susceptible for potential product inhibition. Our findings reveal delicately balanced protease-peptide interactions in viral replication and immune escape that likely restrict the protease adaptive capability and narrow the virus evolutionary space.

Granulocyte-colony stimulating factor (G-CSF) to treat acute-on-chronic liver failure: A multicenter randomized trial (GRAFT study).

BACKGROUND & AIMS: Based on positive results from small single center studies, granulocyte-colony stimulating factor (G-CSF) is being widely used for the treatment of patients with acute-on-chronic liver failure (ACLF). Herein, we aimed to evaluate the safety and efficacy of G-CSF in patients with ACLF. METHODS: In this multicenter, prospective, controlled, open-label phase II study, 176 patients with ACLF (EASL-CLIF criteria) were randomized to receive G-CSF (5 µg/kg daily for the first 5 days and every third day thereafter until day 26) plus standard medical therapy (SMT) (n = 88) or SMT alone. The primary efficacy endpoint was 90-day transplant-free survival analyzed by Cox regression modeling. The key secondary endpoints were overall and transplant-free survival after 360 days, the development of ACLF-related complications, and the course of liver function scores during the entire observation period. RESULTS: Patients treated with G-CSF had a 90-day transplant-free survival rate of 34.1% compared to 37.5% in the SMT group (hazard ratio [HR] 1.05; 95% CI 0.711-1.551; p = 0.805). Transplant-free and overall survival at 360 days did not differ between the 2 arms (HR 0.998; 95% CI 0.697-1.430; p = 0.992 and HR 1.058; 95% CI 0.727-1.548; p = 0.768, respectively). G-CSF did not improve liver function scores, the occurrence of infections, or survival in subgroups of patients without infections, with alcohol-related ACLF, or with ACLF defined by the APASL criteria. Sixty-one serious adverse events were reported in the G-CSF+SMT group and 57 were reported in the SMT group. In total, 7 drug-related serious adverse reactions occurred in the G-CSF group. The study was prematurely terminated due to futility after conditional power calculation. CONCLUSIONS: In contrast to previous findings, G-CSF had no significant beneficial effect on patients with ACLF in this multicenter controlled trial, which suggests that it should not be used as a standard treatment for ACLF. CLINICALTRIALS. GOV NUMBER: NCT02669680 LAY SUMMARY: Granulocyte-colony stimulating factor was considered as a novel treatment for acute-on-chronic liver failure (ACLF). We performed the first randomized, multicenter, controlled phase II trial, which showed that G-CSF did not improve survival or other clinical endpoints in patients with ACLF. Therefore, G-CSF should not be used to treat liver disease outside clinical studies.

Mild versus Severe Liver Injury in SARS-CoV-2 Infection.

BACKGROUND: Abnormal liver function has been reported in patients with COVID-19 infection. The aim of our study was to report on the prevalence of liver injury in our cohort, to evaluate the association of mild versus severe liver injury with mortality in COVID-19 patients and to scrutinize the temporal pattern of viral detection and liver injury. METHODS: We present data from a German cohort of 147 SARS-CoV-2 infected patients. The patients were divided into 3 groups according to their liver status during treatment. The first group included patients without elevated alanine aminotransferase or bilirubin, the third group patients meeting the biochemical criteria of acute liver failure (ALF), and the second group all other patients. RESULTS: Liver injury was detected in 75 (50.7%) and 93 (63%) patients by admission and during treatment, respectively. ALF was associated with the male sex, younger age, and higher BMI. Mortality was associated with the presence of ALF (OR = 9.423, 95% CI: 2.410-36.858) in contrast to milder liver injury (OR 1.101, 95% CI: 0.435-2.791). In 30% of patients with mild liver injury and in 50% of ALF patients, peak liver injury was observed at a time point when the virus was no longer detectable in the respiratory tract. CONCLUSION: Mild liver injury was not associated with worse outcome in our cohort, and the pattern of liver injury did not fit well to the theory of SARS-CoV-2 directly causing liver impairment. Instead, severe liver injury in our cohort was associated multiple-organ failure and acute vascular events.

Quinolone and Multidrug Resistance Predicts Failure of Antibiotic Prophylaxis of Spontaneous Bacterial Peritonitis.

BACKGROUND: The efficacy of antibiotic prophylaxis to prevent spontaneous bacterial peritonitis (SBP) in patients colonized with multidrug-resistant organisms (MDROs) is unknown. We evaluated the effectiveness of fluoroquinolone-based SBP prophylaxis in an era and area of frequent antibiotic resistance. METHODS: This is a prospective observational study in patients with liver cirrhosis and an indication for fluoroquinolone-based prophylaxis of SBP. Patients were recruited and followed in a large German tertiary reference center with comprehensive microbiological and clinical monitoring performed at baseline and after 30, 60, 90, and 180 days of prophylaxis. RESULTS: Overall, 77 patients received antibiotic prophylaxis for an average of 93 days. Baseline prevalence of colonization with MDROs was high (N = 39, 50.6%). At least one de novo MDRO was detected in 27 patients (35.1%) during antibiotic prophylaxis; 33 patients (42.9%) developed secondary infections, including 14 cases (17.9%) of infections with MDROs, and 13 cases (16.9%) of de novo/recurrent SBP. Thirty patients (39.0%) died during follow-up. Significantly higher risks of SBP development during antibiotic prophylaxis were observed for patients with versus without any apparent MDROs (P = .009), vancomycin-resistant enterococci (P = .008), multidrug-resistant gram-negative bacteria (P = .016), or quinolone-resistant gram-negative bacteria (QR-GNB) (P = .015). In competing risk analysis, QR-GNB were independently associated with prophylaxis failure (hazard ratio, 3.39; P = .045) and infections with QR-GNB were independently associated with death before SBP (subdistribution hazard risk, 6.47; P = .034). CONCLUSIONS: Antibiotic prophylaxis of SBP appears to be less efficient in patients with known MDROs. Regular MDRO screening seems to be useful to tailor treatment of secondary infections and re-evaluate antibiotic prophylaxis in case of selection of quinolone resistance.

Managing hepatitis C in patients with the complications of cirrhosis.

Direct acting antivirals (DAA) have revolutionized the treatment of hepatitis C virus (HCV). Sustained virological response rates of nearly 100% have become common in the general population. However, physicians face the growing problem of managing HCV in patients with the complications of cirrhosis, eg hepatic decompensation or hepatocellular carcinoma (HCC). Safety and efficacy remain a clinical challenge in these difficult-to-treat patients. This review focuses on the current state of knowledge and treatment regimens in patients with decompensated cirrhosis as well as the potential risk of the development of HCC following DAA therapy.

Bacterial infection-triggered acute-on-chronic liver failure is associated with increased mortality.

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF) is characterized by an acute deterioration of liver function in patients with cirrhosis in combination with recently defined organ failures. Our aim was to independently validate the prognostic value of the recently established EASL-CLIF-Consortium definition of ACLF and to identify new predictors of short-term mortality. METHODS: Patients with cirrhosis and the International Classification of Diseases, Tenth Revision diagnosis of (sub)acute liver failure were retrospectively categorized according to the EASL-CLIF-Consortium definition. Logistic regression analyses were performed to identify clinical and epidemiological predictors of 30- and 90-day mortality. RESULTS: From 2008 to 2015, 257 patients were included. Overall, 173 (67%) patients met the EASL criteria for ACLF (grade 1: n = 43 [25%], grade 2: n = 52 [30%], grade 3: n = 79 [45%]). Mortality within 30 days in patients without ACLF was 3.6%, and 18.6%, 37.3% and 62.0% in patients with ACLF grades 1, 2 and 3 respectively. Outcome of patients with bacterial infection-triggered ACLF was distinct from non-infection-triggered ACLF (71.6% vs 33.8% 30-day survival, P < .001), and infection-triggered ACLF was independently associated with increased mortality (odds ratio [OR] = 4.28, P < .001). Pneumonia was a particularly frequent infection and burdened with high mortality. In addition, infections with multidrug-resistant organisms were frequent and independently associated with mortality (P = .030, OR = 4.41), as was glycopeptide antibiotic therapy as initial empirical antibiotic therapy (P = .005). CONCLUSIONS: This study confirmed the EASL-CLIF-Consortium definition of ACLF as strong predictor of mortality in patients with acute decompensation of cirrhosis. However, we have observed a remarkably higher mortality in infection-triggered ACLF compared to other precipitating events.

Special populations: treating hepatitis C in patients with decompensated cirrhosis and/or advanced renal impairment.

Direct-acting antivirals have revolutionized the treatment of hepatitis C. Sustained virological response rates of at least 95% have become common in the general population. However, along with the ageing of the HCV population, physicians face a growing group of HCV-infected patients with advanced liver and/or renal impairment. The safety and efficacy of treatment remains a clinical challenge in these patients. This review focuses on the current state of knowledge and treatment regimens in patients with decompensated cirrhosis and severe renal impairment. It shows that distinct interferon-free treatments can achieve favourable sustained virological response rates in these difficult-to-treat patients. Moreover, pitfalls and special considerations as well as new emerging challenges in an era of interferon-free regimens will be presented in this article.

The role of Enterococcus spp. and multidrug-resistant bacteria causing pyogenic liver abscesses.

BACKGROUND: Pyogenic liver abscesses (PLA) remain a significant clinical problem. Unfortunately, little is known about current bacterial susceptibility profiles and the incidence of multidrug resistant organisms (MDROs) causing PLA in Western countries. Yet, this crucial information is pivotal to guide empirical antibiotic therapy. Aim of this study was to provide detailed characteristics of PLA with a special focus on underlying bacterial pathogens and their susceptibility to antibiotics. METHODS: A retrospective study of patients diagnosed with PLA from 2009 to 2015 in a large tertiary reference center in Germany was performed in order to characterize PLA and antimicrobial susceptibility profiles of causative bacterial species. RESULTS: Overall, 86 patients were included. The most common causes of PLA were bile duct stenosis/obstruction (31.4%) and leakage of biliary anastomosis (15.1%). Frequent predisposing diseases were malignancies (34.9%), diabetes (24.4%) and the presence of liver cirrhosis (16.3%). Of note, Enterococcus spp. were the most frequently cultured bacterial isolates (28.9%), and in 1/3 of cases vancomycin resistance was observed. In addition, a relevant frequency of gram-negative MDROs was identified. In particular, an alarming 10% and 20% of gram-negative bacteria were resistant to carbapenems and tigecycline, respectively. Of note, MDRO status did not predict ICU stay or survival in multivariate regression analysis. The mortality rate in our series was 16.3%. CONCLUSION: Our study demonstrates an as yet underreported role of Enterococcus spp., often associated with vancomycin resistance, as well as of gram-negative MDROs causing PLA.

Lactic acidosis in patients with hepatitis C virus cirrhosis and combined ribavirin/sofosbuvir treatment.

BACKGROUND & AIMS: Sofosbuvir (SOF) based interferon-alfa free antiviral therapy has become the treatment of choice for patients with chronic hepatitis C virus (HCV) infection. Little is known about safety of drug combinations using two nucleos(t)ide polymerase inhibitors in patients with HCV associated advanced cirrhosis. Here, we report frequent occurrence of lactic acidosis associated with acute-on-chronic hepatic decompensation during ribavirin (RBV) plus SOF based antiviral therapy. METHODS: Thirty-five patients with chronic hepatitis C and advanced fibrosis, compensated cirrhosis, and decompensated cirrhosis without and after liver transplantation were treated with SOF based antiviral therapy with and without RBV. Adverse events including lactic acidosis (pH <7.35, lactate >20 mg/dl) were recorded 24 weeks before and during (mean ±SD, 18±11 weeks) antiviral therapy. Efficacy was determined by assessment of serum HCV RNA. RESULTS: We observed severe adverse events in 15/35 (43%) patients before (24 weeks) and in 12/35 (34%) patients during antiviral therapy, the majority in association with acute-on-chronic hepatic decompensation. Lactic acidosis occurred in 5/35 (14%) patients during therapy, while no event of lactic acidosis was observed prior to therapy. Lactic acidosis was associated with hepatic decompensation including renal failure and infection, and was severe (pH <7.3) in two patients. CONCLUSIONS: RBV in combination with SOF based antiviral therapy in patients with HCV associated advanced cirrhosis may be associated with the development of lactic acidosis. Impaired renal function, and higher MELD/Child-Pugh scores were identified as potential risk factors.