Monocyte-Derived Hepatocyte-Like Cell Test: A Novel Tool for in vitro Identification of Drug-Induced Liver Injury in Patients with Herbal or Dietary Supplements.

BACKGROUND: Drug-induced liver injury caused by herbal and dietary supplements (HDS) has been an increasingly important phenomenon in recent years. Diagnosis is the major challenge. Definite causality assessment, especially in patients with concomitant prescription medicine or other potential causes of liver injury, can be impossible. OBJECTIVES: We investigated the usefulness of an in vitro test on the basis of peripheral monocytes of the individual patients in patients with acute liver injury consuming HDS. METHOD: Patients with acute liver injury who had been prospectively recruited by the University Hospital Munich (LMU, Munich) and the Chinese University of Hong Kong (CUHK) and who took at least 1 HDS were selected for this analysis. Diagnosis of drug-induced liver injury (DILI) was based on local expert adjudication, Roussel Uclaf Causality Assessment Method (RUCAM) score, and course of the disease and was supported by the monocyte-derived hepatocyte-like (MH) cell test. RESULTS: We identified 47 patients with liver injury and intake of at least 1 HDS: 32 (68%) were diagnosed with DILI. HDS was determined as the causative agent in 28 out of those 32 patients. The MH cell test could correctly identify 29 out of those 32 DILI cases and showed false positive results in only 2 out of the 15 non-DILI patients. The MH cell test therefore reached a sensitivity and specificity of 90.6 and 86.7%, respectively, in patients with acute liver injury and HDS intake. CONCLUSIONS: Our data provide evidence that the MH cell test can be a useful tool to identify the role of HDS in causing DILI and therefore support causality assessment in patients consuming HDS.

Metabolic implication of tigecycline as an efficacious second-line treatment for sorafenib-resistant hepatocellular carcinoma.

Sorafenib represents the current standard of care for patients with advanced-stage hepatocellular carcinoma (HCC). However, acquired drug resistance occurs frequently during therapy and is accompanied by rapid tumor regrowth after sorafenib therapy termination. To identify the mechanism of this therapy-limiting growth resumption, we established robust sorafenib resistance HCC cell models that exhibited mitochondrial dysfunction and chemotherapeutic crossresistance. We found a rapid relapse of tumor cell proliferation after sorafenib withdrawal, which was caused by renewal of mitochondrial structures alongside a metabolic switch toward high electron transport system (ETS) activity. The translation-inhibiting antibiotic tigecycline impaired the biogenesis of mitochondrial DNA-encoded ETS subunits and limited the electron acceptor turnover required for glutamine oxidation. Thereby, tigecycline prevented the tumor relapse in vitro and in murine xenografts in vivo. These results offer a promising second-line therapeutic approach for advanced-stage HCC patients with progressive disease undergoing sorafenib therapy or treatment interruption due to severe adverse events.

Pretreatment with zinc protects Kupffer cells following administration of microbial products.

BACKGROUND: Systemic inflammation and severe fibrosis can reduce serum zinc levels, while zinc supplementation is reported to improve the prognosis of patients with chronic liver disease (CLD). OBJECTIVES: We aimed to investigate the clinical application of serum zinc in patients with CLD and the anti-infective mechanism of zinc supplementation. METHODS: Based on the serum zinc level, 149 CLD patients were divided into 3 groups and their clinical parameters were compared. In in-vitro experiments, microbial isolates derived from patients were used to stimulate human liver non-parenchymal cells, and the zinc sulfate solution was added in certain experiments. The effect of zinc was compared by LDH and thromboxane A2 levels in the cell supernatant. RESULT: Compared with other groups, patients with low serum zinc levels had significantly higher C-reactive protein (CRP), total bilirubin, INR, creatinine, and MELD scores, while albumin and GOT levels were reduced. Only CRP and albumin were significantly correlated with serum zinc in both low and normal-zinc groups. Bacterial isolates significantly increased LDH levels in Kupffer cells (KCs) and stellate cells but had no effect on sinusoidal endothelial cells, whereas zinc pretreatment protected KCs but not stellate cells. Thromboxane A2 secreted by KCs can also be induced by bacterial stimulation, accompanied by increased gene expression of Myd88, MAPK and NF-kB, while zinc pretreatment can attenuate that. CONCLUSION: Serum zinc levels can be used to estimate infection and liver fibrosis in CLD patients. As a new antibacterial weapon, zinc supplementation acts on KCs through Myd88-MAPK related pathways.

Antifibrotic effects of hypocalcemic vitamin D analogs in murine and human hepatic stellate cells and in the CCl4 mouse model.

Liver cirrhosis is a life-threatening consequence of liver fibrosis. The aim of this study was to investigate the antifibrotic potential of clinically available vitamin D analogs compared to that of calcitriol in vitro and in vivo. Murine hepatic stellate cells, Kupffer cells, and human LX-2 cells were treated with vitamin D analogs, and the profibrotic behavior of these cells was studied. In vivo liver fibrosis was induced using CCl4 until measurable fibrosis was established. Animals were then treated with calcitriol and paricalcitol. Vitamin D and its analogs showed antifibrotic effects in vitro. Treatment with active vitamin D (calcitriol, CAL) and its analogs reduced the protein expression of α-smooth muscle actin (α-SMA) in mHSC. In human LX-2 cells alfacalcidol reduced transforming growth factor-ß (TGF-ß) induced platelet-derived growth factor receptor-ß protein expression and contractility while paricalcitol (PCT), in its equipotent dose to CAL, reduced TGF-ß induced α-SMA protein expression, and ACTA2 and TGF-ß mRNA expression. No effects of a treatment with vitamin D and its analogs were observed in Kupffer cells. In vivo, PCT-treated mice had significantly lower calcium levels than CAL-treated mice. CAL and PCT reduced the hepatic infiltration of CD11b-positive cells and alanine transaminase levels, while PCT but not CAL significantly inhibited fibrosis progression, with a favorable side effect profile in the CCl4 model. We conclude that hypocalcemic vitamin D analogs should be considered in future studies investigating vitamin D for the treatment of liver fibrosis.

Drug-Drug Combinations Can Enhance Toxicity as Shown by Monocyte-Derived Hepatocyte-like Cells From Patients With Idiosyncratic Drug-Induced Liver Injury.

Drug-induced liver injury (DILI) is a major cause for acute liver failure and regulatory actions on novel drugs. Individual patient characteristics are the main determinant of idiosyncratic DILI, making idiosyncratic DILI (iDILI) one of the most challenging diagnoses in hepatology. Individual drug-drug interactions might play a role in iDILI. However, the current approaches to iDILI diagnosis are focused on single drugs as causative agents. For the present analysis, 48 patients with acute liver injury who took 2 drugs and who were diagnosed as iDILI were investigated. A novel in vitro test was employed using monocyte-derived hepatocyte-like cells (MH cells) generated from these patients. iDILI diagnosis and causality were evaluated using clinical causality assessment supported by Roussel-Uclaf Causality Assessment Method. In 13 of these 48 patients (27%), combinations of drugs increased toxicity in the MH test when compared with the single drugs. Interestingly, whereas in 24 cases (50%) drug-drug combinations did not enhance toxicity, in 11 cases (23%) only the combinations caused toxicity. The incidence of severe cases fulfilling Hy's law was higher in patients with positive interactions (57% vs 43%; p = .04), with acute liver failure occurring in 40% versus 8% (p = .01). The most common drug combinations causing increased toxicity were amoxicillin/clavulanate (8 of 9 cases) and diclofenac in combination with steroid hormones (4 of 9 cases). Drug-drug interactions may influence the incidence and/or the severity of idiosyncratic DILI. MH cell testing can identify relevant drug-drug interactions. The data generated by this approach may improve patient safety. STUDY IDENTIFIER: ClinicalTrials.gov NCT02353455.

Evaluating the best empirical antibiotic therapy in patients with acute-on-chronic liver failure and spontaneous bacterial peritonitis.

BACKGROUND/AIMS: Spontaneous bacterial peritonitis (SBP) is a life-threatening complication of advanced cirrhosis. By studying the susceptibility of isolated organisms and analyzing empirical antibiotic therapy combined with clinical outcomes, we aimed to find an improved empirical antibiotic therapy by considering the individual acute-on-chronic liver failure (ACLF) grade for patients with or without sepsis. METHODS: Clinical outcomes of 182 patients were assessed retrospectively with multivariable regression analysis. Each of the 223 isolates was individually evaluated regarding susceptibility results and intrinsic resistances. RESULTS: Piperacillin/tazobactam had the highest antimicrobial susceptibility among monotherapies/fixed combinations, which was significantly lower than combination therapies such as meropenem-linezolid (75.3% vs. 98.5%, P < 0.001). The sensitivity of pathogens to empirical antibiotic therapy correlated with significantly lower inpatient mortality (18.9% vs. 37.0%, P = 0.018), shorter inpatient stay (16.3 ±â€¯10.2 vs. 26.4 ±â€¯21.0 days, P = 0.053) and shorter intensive care treatment (2.1 ±â€¯4.5 vs. 7.9 ±â€¯15.4 days, P = 0.016). The largest difference of mortality was observed in patients with ACLF grade 3 (54.5% vs. 73.1% [sensitive vs. non-sensitive]). CONCLUSION: All SBP patients benefited from efficient empirical antibiotic therapy, regarding the reduced inpatient mortality and complications. For SBP patients with ACLF grade 3 without sepsis, the combination therapy with meropenem-linezolid may be suitable considering the susceptibility results and the concentration in the peritoneal cavity.

Monocyte-derived hepatocyte-like cells for causality assessment of idiosyncratic drug-induced liver injury.

BACKGROUND: Idiosyncratic drug-induced liver injury (iDILI) is a frequent cause of acute liver injury and a serious problem in late stage drug-development. Its diagnosis is one of the most challenging in hepatology, since it is done by exclusion and relies on expert opinion. Until now no reliable in vitro test exists to support the diagnosis of iDILI. In some instances it is impossible to determine the causative drug in polymedicated patients. AIM: To investigate if monocyte-derived hepatocyte-like (MH) cells might be a tool supporting clinical judgment for iDILI diagnosis and causality assessment. METHODS: This prospective study included 54 patients with acute liver injury and intake of at least one drug. Thirty-one patients were diagnosed with iDILI based on causality likelihood. MH cells were generated from every patient and in vitro toxicity of the respective drugs was assessed by lactate-dehydrogenase release. The results from MH cells and RUCAM, the most widely used scoring system as methods to support clinical judgement were compared. RESULTS: MH cells showed enhanced toxicity in 29 of the 31 patients with iDILI, similar to RUCAM score. MH cells exhibited negative results in the 23 non-DILI cases, whereas RUCAM indicated possible iDILI in six cases. Analysis of the comedications also showed superior specificity of MH cells. No MH cell toxicity of the drugs showing toxicity in patients with iDILI was observed in MH cells of healthy donors. CONCLUSIONS: In this pilot study in vitro testing using MH cells derived from patients with acute liver injury was able to identify patients with iDILI with an excellent sensitivity and a higher specificity than RUCAM, the most widely used current causality assessment score. Therefore, MH cells could be useful to identify the causative drugs even in polymedicated patients by adding objective data to causality assessment. TRIAL REGISTRATION NUMBER: NCT02353455.

Human monocyte-derived cells with individual hepatocyte characteristics: a novel tool for personalized in vitro studies.

Gender, ethnicity and individual differences in hepatic metabolism have major impact on individual drug response, adverse events and attrition rate during drug development. Therefore, there is an urgent need for reliable test systems based on human cells. Yet, the use of primary human hepatocytes (PHHs) is restricted by limited availability, invasive preparation and short-term stability in culture. All other cellular approaches proposed so far have major disadvantages. We investigated whether peripheral human monocytes after cultivation according to our novel protocol (monocyte-derived hepatocyte-like cells (MH cells)) can serve as an in vitro model for hepatocyte metabolism. Enzyme activities, synthesis parameters (coagulation factor VII and urea) and cytochrome (CY) P450 activities and induction were investigated. Furthermore, MH cells were compared with PHH from the same donor. Using our protocol, we could generate cells that exhibit hepatocyte-like properties: These cells show 71±9% of specific ALT activity, 41±3% of CYP3A4 activity and 65±13% of factor VII secretion when compared with PHHs. Consequently, CYP-mediated acetaminophen toxicity and drug interactions could be shown. Moreover, the investigated parameters were stable in culture over at least 4 weeks. Furthermore, MH cells retain gender-specific and donor-specific CYP activities and toxicity profiles, respectively. MH cells show quantitative and qualitative approximation to human hepatocytes concerning CYP-metabolism and toxicity. Our data support individual prediction of toxicity and CYP metabolism. MH cells are a novel tool to investigate long-term hepatic toxicity, metabolism and drug interactions.

Amiloride reduces portal hypertension in rat liver cirrhosis.

OBJECTIVE: This study aimed to investigate the effect of amiloride on portal hypertension. Amiloride is known to inhibit Na(+)/H(+) exchangers on activated hepatic stellate cells. METHODS: Liver cirrhosis in rats was induced by bile duct ligation (BDL) or thioacetamide (TAA) administration. The effects of zymosan for Kupffer cell (KC) activation or a thromboxane (TX) analogue (U46619) were tested in isolated perfused livers of cirrhotic rats and in vivo. Downstream mechanisms were investigated using Rho kinase inhibitor (Y-27632) or amiloride. Acute and chronic effects of amiloride and canrenoate on portal pressure were compared in perfused livers and in vivo. TXB(2) efflux was measured by ELISA. The phosphorylation state of moesin (p-moesin) as an indicator of Rho kinase activity and expression of the thromboxane synthase were assessed by western blot analyses. The activity of hepatic stellate cells was analysed by western blot and staining for alpha-smooth muscle actin (alpha-SMA). RESULTS: In BDL rats, KC activation via zymosan increased portal pressure. This was attenuated by the Rho kinase inhibitor Y-27632. Increased thromboxane efflux following zymosan infusion remained unaltered by Y-27632. The infusion of amiloride attenuated zymosan- and U46619-induced increases in portal perfusion pressure. In vivo, direct administration of amiloride, but not of canrenoate, lowered portal pressure. In TAA and BDL rats, treatment with amiloride for 3 days reduced basal portal pressure and KC-induced increases in portal pressure whereas canrenoate had no effect. In livers of amiloride-treated animals, the phosphorylation state of moesin and the number of alpha-SMA positive cells were reduced. CONCLUSIONS: Amiloride lowers portal pressure in rat liver cirrhosis by inhibition of intrahepatic vasocontraction. Therefore, patients with cirrhosis and portal hypertension may benefit from amiloride therapy.

Ischaemic and pharmacological preconditionings protect liver via adenosine and redox status following hepatic ischaemia/reperfusion in rats.

Although IPC (ischaemic preconditioning) is considered as a protective strategy in HI/R (hepatic ischaemia/reperfusion), the mechanisms for this effect have not been fully elucidated. In the present study we investigate whether PPC (pharmacological preconditioning) by transient activation of A(1)R (adenosine A(1) receptor) protects against long-term HI/R and whether the protective effects of IPC depend on A(1)R activation and whether both preconditionings affect remote organs. Wistar rats underwent IPC and long-term HI/R. Another set of animals were pharmacologically preconditioned with the A(1)R-agonist CCPA [2-chloro-N(6)-cyclopentyladenosine; 0.1 mg/kg of body weight, i.p. (intraperitoneally)] 24 h before HI/R. In other groups, rats received an A(1)R-antagonist, DPCPX (1,3-dipropyl-8-cyclopentylxanthine; 0.1 mg/kg of body weight, i.p.) 24 h before HI/R. Hepatic damage was evaluated by transaminase [AST (aspartate transaminase), ALT (alanine transaminase)] release; inflammation was assessed by hepatic MPO (myeloperoxidase) and serum TNFalpha (tumour necrosis factor alpha) and NO; oxidative stress was estimated by MDA (malondialdehyde) and 4-HDA (4-hydroxyalkenals), SOD (superoxide dismutase) activity, GSH and ADA (adenosine deaminase) as adenosine metabolism. Both preconditionings protected liver and lung against HI/R as indicated by the reduction in transaminases, MPO, MDA+4-HDA, NO, TNFalpha and ADA activity as compared with HI/R (P<0.05). However, pre-treatment with DPCPX abolished the protective effects of IPC and PPC. Preconditionings induced a significant increase in hepatic MnSOD (manganese SOD) activity and NO generation compared with the sham group, and this activity was abolished by DPCPX pre-treatment. A(1)R activation induced hepatic delayed preconditioning and blockade of A(1)R abolished hepatic IPC. IPC, as well as PPC, were able to prevent lung damage. These protective effects are associated with a reduction in oxidative stress, inflammation and endogenous antioxidant preservation.

Treatment of Crigler-Najjar type 1 disease: relevance of early liver transplantation.

BACKGROUND: Crigler-Najjar syndrome type 1 (CNS1) is characterized by severe unconjugated hyperbilirubinemia from birth, caused by total failure of UDP-glucuronyltransferase activity. Only orthotopic liver transplantation (OLT) offers the prospect of cure. However, because the onset of neurologic deficits is unpredictable, timing of OLT remains difficult. METHODS: In our transplant center, 3 patients underwent early OLT for CNS1. Two of them (7 yr, 12 yr) showed mild to moderate neurologic deficits only few weeks before OLT, another patient (4 yr) had no signs of bilirubin encephalopathy. All patients required extensive phototherapy to control bilirubin levels. Thus, OLT was performed shortly after the onset of neurologic symptoms or as a prophylactic procedure, respectively. RESULTS: OLT was uneventful in all recipients. One of the symptomatic patients (7 yr) completely recovered from neurologic deficits at 36 months on OLT, whereas the other patient (12 yr) significantly improved symptoms at 27 months of OLT. These patients, including the 4-year-old boy, attend school at appropriate grades now. CONCLUSIONS: Irreversible brain damage (kernicterus) may occur in the course of CNS1 disease. Because no alternative treatment options are available at this time, OLT should be performed as a preventive procedure to counteract severe CNS-related complications.