Rudolf E. Stauber

Physiological and pathological changes in the redox state of human serum albumin critically influence its binding properties

Binding and transport of a number of endogenous and exogenous compounds is an important function of the main plasma protein, albumin. In vivo and in vitro, albumin may be oxidatively modified in different ways with different agents at different sites. These modifications have various consequences on the physiological functions of albumin. Diabetes mellitus, liver diseases and nephropathy are just a few examples of disorders in which oxidative stress is involved and altered albumin functions have been described. This review is focussed on the consequences of oxidative modification on the binding properties of albumin. These range from no effect to decreased or increased binding affinities depending on the ligand under investigation and the type of modification. Indicators for modification include glycosylation, disulphide formation or the content of carbonyl groups. The redox state of albumin can affect the binding properties in several ways, including altered conformation and consequently altered affinities at binding sites and altered binding when the binding reaction itself is redox sensitive. The physiological or pathophysiological concentrations of different oxidatively modified albumin molecules vary over a wide range and are crucial in assessing the clinical relevance of altered ligand binding properties of a particularly modified albumin species in various disease conditions.

Inflammation-induced cholestasis.

Inflammatory cytokines produced in response to various infectious and non‐infectious stimuli are potent inducers of intrahepatic cholestasis (inflammation‐induced cholestasis). The cholestatic effect of cytokines results mainly from inhibition of expression and function of hepatocellular transport systems which normally mediate hepatic uptake and biliary excretion of bile salts and various non‐bile salt organic anions (e.g. bilirubin). These cytokine effects are reversible and bile secretory function is restored upon disappearance of the inflammatory injury. This review summarizes the clinical, pathophysiological and molecular aspects of inflammation‐induced cholestasis.

Impact of IL28B Genotype on the Early and Sustained Virologic Response in Treatment-Naïve Patients With Chronic Hepatitis C

BACKGROUND & AIMS Single nucleotide polymorphisms (SNPs) in the gene that encodes interleukin (IL)-28B predict response of patients with chronic hepatitis C to antiviral therapy. We investigated the roles of polymorphisms rs12979860 and rs8099917 on the early virologic response of treatment-naïve patients. METHODS SNPs were identified by real-time polymerase chain reaction analysis of samples from 682 patients (genotype [GT]1=372, GT2/3=208, GT4=102) who were treated with 180 μg pegylated interferon-α2a and 400 or 800 mg (GT2/3, depending on the protocol) or 1000-1200 mg (GT1/4) ribavirin/day. The duration of treatment was 24 (GT2/3) or 24-72 weeks (GT1/4). RESULTS Patients with C/C also had higher rates of rapid virologic response (RVR) (GT1, 38.3% vs 11.6%; GT4, 76.5% vs 23.5%; both P<.001) and sustained virologic responses (SVRs) (GT1, 79.1% vs 43.2%; GT4, 85.3% vs 44.1%; both P<.001). In patients with GT2/3, the RVR was more frequent in carriers of C/C (75.3% vs 52.6%, P<.01), but SVR rates were similar between those with C/C and T (80.5% vs 74.4%, P=.31). Results for rs8099917 were comparable. The positive predictive value of rs12979860 C/C for SVR was higher than that of rs8099917 T/T (80.5% vs 71.6%). Overall, RVR was the best predictor of SVR. In patients who did not have GT1, IL28B polymorphisms did not affect the SVR if RVR data were included in the multivariate analysis. CONCLUSIONS An early virologic response to pegylated interferon and ribavirin is more likely among carriers of rs12979860 C/C and rs8099917 T/T, which might underlie their high rates of SVR. Determination of the IL28B genotype and whether patients have an RVR might be used in future studies of patients with hepatitis C virus genotype 1 or 4.

Historical epidemiology of hepatitis C virus (HCV) in selected countries

Chronic infection with hepatitis C virus (HCV) is a leading indicator for liver disease. New treatment options are becoming available, and there is a need to characterize the epidemiology and disease burden of HCV. Data for prevalence, viremia, genotype, diagnosis and treatment were obtained through literature searches and expert consensus for 16 countries. For some countries, data from centralized registries were used to estimate diagnosis and treatment rates. Data for the number of liver transplants and the proportion attributable to HCV were obtained from centralized databases. Viremic prevalence estimates varied widely between countries, ranging from 0.3% in Austria, England and Germany to 8.5% in Egypt. The largest viremic populations were in Egypt, with 6 358 000 cases in 2008 and Brazil with 2 106 000 cases in 2007. The age distribution of cases differed between countries. In most countries, prevalence rates were higher among males, reflecting higher rates of injection drug use. Diagnosis, treatment and transplant levels also differed considerably between countries. Reliable estimates characterizing HCV‐infected populations are critical for addressing HCV‐related morbidity and mortality. There is a need to quantify the burden of chronic HCV infection at the national level.

Clinical Course of acute-on-chronic liver failure syndrome and effects on prognosis.

Acute‐on‐chronic liver failure (ACLF) is characterized by acute decompensation (AD) of cirrhosis, organ failure(s), and high 28‐day mortality. We investigated whether assessments of patients at specific time points predicted their need for liver transplantation (LT) or the potential futility of their care. We assessed clinical courses of 388 patients who had ACLF at enrollment, from February through September 2011, or during early (28‐day) follow‐up of the prospective multicenter European Chronic Liver Failure (CLIF) ACLF in Cirrhosis study. We assessed ACLF grades at different time points to define disease resolution, improvement, worsening, or steady or fluctuating course. ACLF resolved or improved in 49.2%, had a steady or fluctuating course in 30.4%, and worsened in 20.4%. The 28‐day transplant‐free mortality was low‐to‐moderate (6%‐18%) in patients with nonsevere early course (final no ACLF or ACLF‐1) and high‐to‐very high (42%‐92%) in those with severe early course (final ACLF‐2 or ‐3) independently of initial grades. Independent predictors of course severity were CLIF Consortium ACLF score (CLIF‐C ACLFs) and presence of liver failure (total bilirubin ≥12 mg/dL) at ACLF diagnosis. Eighty‐one percent had their final ACLF grade at 1 week, resulting in accurate prediction of short‐ (28‐day) and mid‐term (90‐day) mortality by ACLF grade at 3‐7 days. Among patients that underwent early LT, 75% survived for at least 1 year. Among patients with ≥4 organ failures, or CLIF‐C ACLFs >64 at days 3‐7 days, and did not undergo LT, mortality was 100% by 28 days. Conclusions: Assessment of ACLF patients at 3‐7 days of the syndrome provides a tool to define the emergency of LT and a rational basis for intensive care discontinuation owing to futility. (Hepatology 2015;62:243‐252)

Diagnostic Value of Quantitative Hepatic Copper Determination in Patients With Wilson’s Disease

BACKGROUND & AIMS A 5-fold increase of hepatic copper concentration is considered as the best available test for diagnosis of hepatic Wilsons disease (WD). However, the sensitivity and specificity of this test have never been fully investigated. METHODS Copper content was measured by flame atomic absorption spectroscopy in 114 liver biopsies obtained at diagnosis of WD, in 219 patients with noncholestatic liver diseases (including 144 with chronic hepatitis C and 44 with nonalcoholic fatty liver disease), and in 26 without evidence of liver disease. RESULTS Liver copper content was >250 microg/g in 95 WD patients (83.3%), between 50 and 250 microg/g in 15, and below 50 microg/g in 4. It did not correlate with age (r(2) = .003), the grade of fibrosis, or the presence of stainable copper. Liver copper content was >250 or between 50 and 250 microg/g in 3 (1.4%) and 20 (9.1%) of 219 patients with noncholestatic liver diseases, respectively. By lowering the cutoff from 250 to 75 microg/g, the sensitivity of liver copper content to diagnose WD increased from 83.3% (95% confidence interval, 75.2%-89.6%) to 96.5% (91.3%-99.1%), but the specificity decreased from 98.6% (96.0%-99.7%) to 95.4% (91.8%-97.8%). CONCLUSIONS There is no gold standard for the diagnosis of WD. Liver copper content is a useful parameter, but a value below 250 microg/g does not exclude WD. Diagnosis requires the combination of a variety of clinical and biochemical tests.

Strategies to manage hepatitis C virus (HCV) disease burden

The number of hepatitis C virus (HCV) infections is projected to decline while those with advanced liver disease will increase. A modeling approach was used to forecast two treatment scenarios: (i) the impact of increased treatment efficacy while keeping the number of treated patients constant and (ii) increasing efficacy and treatment rate. This analysis suggests that successful diagnosis and treatment of a small proportion of patients can contribute significantly to the reduction of disease burden in the countries studied. The largest reduction in HCV‐related morbidity and mortality occurs when increased treatment is combined with higher efficacy therapies, generally in combination with increased diagnosis. With a treatment rate of approximately 10%, this analysis suggests it is possible to achieve elimination of HCV (defined as a >90% decline in total infections by 2030). However, for most countries presented, this will require a 3–5 fold increase in diagnosis and/or treatment. Thus, building the public health and clinical provider capacity for improved diagnosis and treatment will be critical.

Advanced-Stage Hepatocellular Carcinoma: Transarterial Chemoembolization versus Sorafenib

PURPOSE To compare the efficacies of transarterial chemoembolization (TACE) and sorafenib in patients with advanced-stage hepatocellular carcinoma (HCC). MATERIALS AND METHODS The retrospective analysis of the data was approved by the institutional review board; the requirement to obtain informed consent was waived. Three hundred seventy-two patients with HCC were treated between January 1999 and December 2009. Patients with advanced HCC according to the Barcelona Clinic Liver Cancer (BCLC) staging classification (Child-Pugh class A or B, Eastern Cooperative Oncology Group performance status of 1-2, and/or macrovascular invasion or extrahepatic metastasis) were included in the study (n = 97). Thirty-four patients underwent conventional TACE with doxorubicin plus lipiodol or TACE with drug-eluting beads; 63 patients were treated with sorafenib. RESULTS The median duration of sorafenib treatment was 4.6 months (95% confidence interval [CI]: 3.2, 6.0 months). The median number of TACE sessions per patient was 3 ± 2. Side effects of TACE and sorafenib were comparable to those reported in the literature. The median time to progression was similar between the two treatment groups (P = .737). The median overall survival was 9.2 months (95% CI: 6.1, 12.3 months) for patients treated with TACE and 7.4 months (95% CI: 5.6, 9.2 months) for those treated with sorafenib (P = .377). Only Child-Pugh class was associated with a better overall survival at uni- and multivariate analysis. CONCLUSION TACE achieved a promising outcome in select patients with advanced HCC (BCLC stage C).

Oxidative damage of albumin in advanced liver disease

Albumin has a number of biological functions and the serum albumin level is related to prognosis in advanced liver disease. Oxidative stress is believed to play an important role in the pathogenesis of liver failure. The aim of the present study was to characterize oxidative modification of albumin in patients with various degrees of liver failure and to investigate implications for its binding function. Patients with liver cirrhosis (n=10), acute-on-chronic liver failure (n=8) and healthy controls (n=15) were included in the study. Three fractions of albumin were separated by HPLC according to the redox state of cysteine-34 and detected by fluorescence as well as UV absorption. Carbonyl groups were measured as a marker of oxidative modification in plasma proteins and, by western blotting, on albumin. Progressive oxidative modification of albumin was found with increasing severity of liver failure indicated by an increased content of carbonyl groups and oxidation of cysteine-34. Fluorescence properties of albumin were altered by oxidation and, in patients with acute-on-chronic liver failure, by high plasma levels of bilirubin. This alteration of albumin fluorescence by bilirubin provides evidence for a preferred binding of bilirubin to the fully reduced form of albumin.

Effect of extracorporeal liver support by MARS and Prometheus on serum cytokines in acute-on-chronic liver failure

IntroductionCytokines are believed to play an important role in acute-on-chronic liver failure (ACLF). Extracorporeal liver support systems may exert beneficial effects in ACLF via removal of cytokines. At present, two systems are commercially available, the Molecular Adsorbent Recirculating System (MARS™) and Fractionated Plasma Separation, Adsorption and Dialysis (Prometheus™). The aim of this study was to compare the effects of MARS and Prometheus treatments on serum cytokine levels and their clearances.MethodsEight patients with ACLF underwent alternating treatments with either MARS or Prometheus in a randomized cross-over design. Thirty-four treatments (17 MARS, 17 Prometheus) were available for analysis. Serum cytokines were measured before and after each treatment, and cytokine clearance was calculated from paired arterial and venous samples and effective plasma flow one hour after the start of treatment.ResultsBaseline serum levels of interleukin (IL)-6, IL-8, IL-10, tumor necrosis factor-alpha (TNF-α), and soluble TNF-α receptor 1 were significantly elevated in patients with ACLF. Measurable plasma clearances were detected for all cytokines tested, but no significant changes in serum levels of any cytokine were found after treatments with MARS or Prometheus. In MARS treatments, IL-10 was cleared from plasma more efficiently than IL-6. Clearance of IL-10 was higher in Prometheus than in MARS treatments.ConclusionCytokines are cleared from plasma by both MARS and Prometheus, but neither system is able to change serum cytokine levels. This discrepancy is probably due to a high rate of cytokine production in patients with ACLF.