Antiviral Treatment and Liver- Related Complications in Hepatitis Delta
HEPATOLOGY
Authors: Wranke, Anika; Serrano, Beatriz Calle; Heidrich, Benjamin; Kirschner, Janina; Bremer, Birgit; Lehmann, Patrick; Hardtke, Svenja; Deterding, Katja; Port, Kerstin; Westphal, Max; Manns, Michael P.; Cornberg, Markus; Wedemeyer, Heiner
Abstract
Hepatitis delta virus (HDV) is the most severe form of viral hepatitis. Pegylated interferon alfa (PEG-IFNa) is effective in only 25%-30% of patients and is associated with frequent side effects. The aim of this study was to analyze the clinical long-term outcome of hepatitis delta in relation to different antiviral treatment strategies. We studied 136 anti-HDVpositive patients who were followed for at least 6 months in a retrospective single-center cohort (mean time of follow-up, 5.2 years; range, 0.6-18.8). Liver cirrhosis was already present in 62 patients at first presentation. Twenty-nine percent of patients did not receive any antiviral treatment, 38% were treated with interferon alfa (IFNa)-based therapies, and 33% received nucleos(t) ide analogues (NAs) only. Clinical endpoints defined as hepatic decompensation (ascites, encephalopathy, and variceal bleeding), hepatocellular carcinoma, liver transplantation, and liver-related death developed in 55 patients (40%). Patients who received IFNa-based therapies developed clinical endpoints less frequently than those treated with NA (P = 0.02; HR, 4.0) or untreated patients (P = 0.05; HR, 2.2; 17%, 64%, and 44%), respectively, which was significant in both chi-square and Kaplan-Meier analysis. In addition, considering various clinical and virological parameters, IFNa therapy was independently associated with a more benign clinical long-term outcome in multivariate logistic regression analysis (P = 0.04; odds ratio, 0.25; 95% confidence interval, 0.07-0.9). Loss of HDV RNA during follow-up was more frequent in IFNa-treated patients and strongly linked with a lower likelihood to experience liver-related complications. Conclusion: IFNa-based antiviral therapy of hepatitis delta was independently associated with a lower likelihood for clinical disease progression. Durable undetectability of HDV RNA is a valid surrogate endpoint in the treatment of hepatitis delta.
Increasing fatigue performance in AHSS thick sheet by surface treatments
12TH INTERNATIONAL FATIGUE CONGRESS (FATIGUE 2018)
Authors: Parareda, Sergi; Lara, Antoni; Sieurin, Henrik; D'Armas, Heber; Casellas, Daniel
Abstract
Advanced High Strength Steels (AHSS) have been widely applied in the automotive industry as an affordable solution for car lightweighting, mainly in parts subjected to crash requirements. Heavy duty vehicle (HDV) can also benefit from the expertise learned in cars, but parts must be designed considering fatigue resistance, especially on trimmed areas, and stiffness. Mechanical surface treatments, as blasting or shot peening, help increasing fatigue life of AHSS in trimmed areas and will allow weight reduction in HDV through gauge downsizing. The expected decrease in stiffness through thickness reduction can be improved by design changes. However, scarce information about the effect of mechanical surface treatments on AHSS are available. Thus, the aim of this work is to evaluate the increment in fatigue life of two different steel grades (350 MPa, and 500MPa of yield strength) in thick sheet by means of mechanical surface treatment - sandblasting. High Cycle Fatigue [HCF] tests were conducted at alternating load [R=-1]. Residual stresses were measured by an X-ray tensometry prior fatigue tests. Also the surface roughness [Rz] and form is measured using an optical non-contact 3D microscope. On the other hand, the fracture surfaces of the test specimens were observed via scanning electron microscope (SEM) in order to determine the crack initiation points. The evaluation of fatigue life in terms of SN curves is also discussed, analysing how the sandblasting process modifies the surface roughness and introduce compressive residual stresses on the external layer of the material. Both phenomena enhance the fatigue strength of the evaluated steel grades.