Robert Strassl
Medical University of Vienna
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Featured researches published by Robert Strassl.
Gastroenterology | 2012
Sandra Beinhardt; Judith H. Aberle; Michael Strasser; Emina Dulic–Lakovic; A Maieron; Anna Kreil; Karoline Rutter; A.F. Staettermayer; Christian Datz; Thomas Matthias Scherzer; Robert Strassl; Martin Bischof; Rudolf E. Stauber; Gerd Bodlaj; H. Laferl; Heidemarie Holzmann; Petra Steindl–Munda; Peter Ferenci; Harald Hofer
BACKGROUND & AIMS Single nucleotide polymorphisms (SNPs) in IL28B and serum levels of interferon γ inducible protein 10 (IP-10) predict outcomes of antiviral therapy in patients with chronic hepatitis C. We associated IL28B SNPs rs12979860 and rs8099917, along with serum levels of IP-10, with outcomes of patients with acute hepatitis C (AHC). METHODS We studied 120 patients with AHC (64 male; 37 ± 16 years old) and 96 healthy individuals (controls). The IL28B SNPs rs12979860 and rs8099917 were detected using real-time polymerase chain reaction; serum concentrations of IP-10 were measured by enzyme-linked immunosorbent assays of 62 patients with AHC. RESULTS Hepatitis C virus was cleared spontaneously from 59 patients (49.2%). The IL28B rs12979860 C/C genotype was more frequent among patients with AHC than controls (62.5% vs 39.6%; P < .001) and among patients with spontaneous clearance than those without (74.6% vs 51.7%; P = .02) (positive predictive value, 60.3%). Patients with IL28B rs12979860 C/C more frequently developed jaundice (53.2% vs 27.6%; P = .022) than carriers of the T allele. The median level of IP-10 was lower among patients with AHC and spontaneous clearance (764 [113-2470] pg/mL) than those without spontaneous clearance (1481 [141-4412] pg/mL; P = .006). Based on receiver operating characteristic analysis, 540 pg/mL IP-10 was set as the cutoff for patients most likely to have spontaneous clearance (positive predictive value, 71.4%; negative predictive value, 65.9%). Including data on IP-10 levels increased the ability of the IL28B rs12979860 C/C to identify patients most likely to have spontaneous clearance (83% of those who had an IP-10 level <540 pg/mL and 32% who had an IP-10 level >540 pg/mL) (P < .01). CONCLUSIONS The combination of serum level of IP-10 and SNPs in IL28B can identify patients with AHC who are most likely to undergo spontaneous clearance and those in need of early antiviral therapy.
Alimentary Pharmacology & Therapeutics | 2014
Albert Friedrich Stättermayer; Robert Strassl; A. Maieron; Karoline Rutter; Rudolf E. Stauber; M. Strasser; Sandra Beinhardt; Christian Datz; Thomas-Matthias Scherzer; Petra Steindl-Munda; M. Gschwantler; Michael Trauner; Harald Hofer; Peter Ferenci
The IL28B genotype in rs12979860 predicts success of peginterferon/ribavirin (PEG/RBV) therapy in patients with chronic hepatitis C (CHC). Recently, a dinucleotide frame shift variant in ss469415590 (TT or ΔG) was described, which generates the novel interferon lambda 4 protein (IFNL4). IFNL4 ss469415590 (ΔG) allele carriers have an impaired clearance of HCV infection and response to IFN‐α therapy. In this study, we compared the role of IFNL4 polymorphism with the two commonly used IL28B SNPs rs12979860 and rs8099917 on response to PEG/RBV in patients with CHC.
Journal of Viral Hepatitis | 2012
Lana Kosi; Thomas Reiberger; Ba Payer; Katharina Grabmeier-Pfistershammer; Robert Strassl; Armin Rieger; Markus Peck-Radosavljevic
Summary. Data on the efficacy of lamivudine (LAM)‐, tenofovir (TDF)‐ and emtricitabine (FTC)‐based antiretroviral therapy (HAART) in HBV–HIV coinfection are limited. We completed a retrospective analysis of HBV–HIV‐coinfected patients treated at the Medical University of Vienna. One‐hundred and ten coinfected patients were included, with 57% being initially HBV e‐Antigen (HBeAg) positive. Baseline HBV load was significantly higher in HBeAg+ than in HBeAg− patients (5962 ± 3663 vs 20 ± 19 × 106 IU/mL; P < 0.0001). Over a median observation period of 83 month (range: 26–183), 87% received HAART and 91% showed a suppression of HBV replication. After 5 years of continuous treatment, HBeAg seroconversion was achieved in 21% of LAM‐, 50% of TDF‐ (P = 0.042 vs LAM) and in 57% of TDF + FTC (P = 0.008 vs LAM)‐treated patients, respectively. HBsAg loss after 5 years was found in 8% (LAM), 25% (TDF; P = 0.085 vs LAM) and 29% (TDF + FTC; P = 0.037 vs LAM) of HBeAg+ patients. In HBeAg− patients, HBsAg loss was achieved in 11% (LAM), 27% (TDF; P = 0.263 vs LAM) and 36% (TDF + FTC; P = 0.05 vs LAM), respectively. Pretreatment CD4+ counts did not influence rates of HBeAg seroconversion and of HBsAg loss. Patients with HBsAg loss had lower baseline HBV‐DNA levels and higher AST/ALT levels than patients without HBsAg loss. Transient HAART‐related hepatotoxicity was found in 32% (Grade I: 21%; II:7%; III:2%; IV:0%). Most HBV–HIV‐coinfected patients achieve complete suppression of HBV replication despite high baseline viremia. TDF‐based HAART leads to high rates of HBeAg seroconversion and HBsAg loss after 5 years of continuous exposure. One‐third of HBV–HIV‐coinfected patients may experience transient HAART‐related hepatotoxicity.
Alimentary Pharmacology & Therapeutics | 2013
Karoline Rutter; Harald Hofer; Sandra Beinhardt; M. Dulic; M. Gschwantler; A. Maieron; H. Laferl; Albert Friedrich Stättermayer; Thomas-Matthias Scherzer; Robert Strassl; Heidemarie Holzmann; Petra Steindl-Munda; Peter Ferenci
The introduction of direct‐acting anti‐virals has increased sustained virological response (SVR) rates in chronic hepatitis C genotype 1 infection. At present, data on long‐term durability of viral eradication after successful triple therapy are lacking.
Pediatric Infectious Disease Journal | 2012
Manuel Steiner; Robert Strassl; Julia Straub; Judith Böhm; Theresia Popow-Kraupp; Angelika Berger
During 11 months, all preterm infants admitted to our neonatal care facility with suspected respiratory tract infection were screened for respiratory viruses by polymerase chain reaction. Rhinovirus infection was identified in 16 infants, leading to severe respiratory compromise in most cases. Distribution of rhinovirus infections during the year showed a strong clustering trend, suggesting a major role for nosocomial transmission.
PLOS ONE | 2015
Robert Strassl; Karoline Rutter; Albert Friedrich Stättermayer; Sandra Beinhardt; Michael Kammer; Harald Hofer; Peter Ferenci; Theresia Popow-Kraupp
Background and Aims Monitoring of chronic Hepatitis C (CHC) treatment relies on HCV RNA quantification by means of real-time PCR methods. Assay specific analytical sensitivities may impact therapy management. Methods Comparative analysis between three commercial assays (Roche COBAS AmpliPrep/COBAS TaqMan Version 1 (CAP/CTM Ver. 1), Version 2 (CAP/CTM Ver. 2) and the Abbott RealTime HCV (ART) assay) was performed on 247 available samples taken at key decision time points during antiviral therapy of 105 genotype 1 patients (triple therapy: n = 70; dual therapy: n = 35). Results Overall concordance of HCV RNA measurements was high between the two Roche systems (89%; n = 220/247) but lower between the Roche assays and the ART (CAP/CTM Ver. 1 vs ART: 77.3%; n = 191/247 and CAP/CTM v.2 vs ART: 80.1%; n = 198/247). Most discrepancies were noted in week 4/8 samples with residual viremia (<LLOQ) detected by ART (<LLOQ: n = 45, 44.1%) but undetectable HCV RNA by CAP/CTM Ver. 1 (<LLOQ: n = 18, 17.6%) or CAP/CTM Ver. 2 (<LLOQ: n = 26, 25.5%). Based on results by CAP/CTM Ver. 1, 13 eligible patients underwent an abbreviated course of therapy (24 weeks). Only 1 patient experienced virologic breakthrough. If tested by ART, only 6/13 patients (46.2%) would have been eligible for shortened treatment. Consequently, RGT guidelines were adapted and shortening of therapy was allowed if residual viremia was detected by ART at week 4/8. Conclusion An abbreviated course of treatment can safely be applied in patients with residual viremia (<LLOQ) detected by ART in samples collected at week 4/8 of treatment.
PLOS ONE | 2013
Katrina Vanura; Franz J.J. Rieder; Marie-Theres Kastner; Julia Biebl; Michael Sandhofer; Trang Le; Robert Strassl; Elisabeth Puchhammer-Stöckl; Thomas Perkmann; Christoph Steininger; Kostas Stamatopoulos; Wolfgang Graninger; Ulrich Jäger
Chronic lymphocytic leukemia (CLL) is characterized by progressive hypogammaglobulinemia predisposing affected patients to a variety of infectious diseases but paradoxically not to cytomegalovirus (CMV) disease. Moreover, we found reactivity of a panel of CLL recombinant antibodies (CLL-rAbs) encoded by a germ-line allele with a single CMV protein, pUL32, despite differing antibody binding motifs. To put these findings into perspective, we studied prospectively relative frequency of viremia, kinetics of total and virus-specific IgG over time, and UL32 genetic variation in a cohort of therapy-naive patients (n=200). CMV-DNA was detected in 3% (6/200) of patients. The decay of total IgG was uniform (mean, 0.03; SD, 0.03) and correlated with that of IgG subclasses 1-4 in the paired samples available (n=64; p<0.001). Total CMV-specific IgG kinetics were more variable (mean, 0,02; SD, 0,06) and mean decay values differed significantly from those of total IgG (p=0.034). Boosts of CMV-specific antibody levels were observed in 49% (22/45) of CMV-seropositive patients. In contrast, VZV- and EBV-specific IgG levels decayed in parallel with total IgG levels (p=0.003 and p=0.001, respectively). VZV-specific IgG even became undetectable in 18% (9/50) of patients whereas CMV-specific ones remained detectable in all seropositive patients. The observed CMV-specific IgG kinetics were predicated upon the highly divergent kinetics of IgG specific for individual antigens - glycoprotein B-specific IgG were boosted in 51% and pUL32-specific IgG in 32% of patients. In conclusion, CLL patients have a preserved CMV-specific antibody response despite progressive decay of total IgG and IgG subclasses. CMV-specific IgG levels are frequently boosted in contrast to that of other herpesviruses indicative of a higher rate of CMV reactivation and antigen-presentation. In contrast to the reactivity of multiple different CLL-rAbs with pUL32, boosts of humoral immunity are triggered apparently by other CMV antigens than pUL32, like glycoprotein B.
Journal of Viral Hepatitis | 2014
Robert Strassl; Thomas Reiberger; C. Honsig; Ba Payer; Mattias Mandorfer; Katharina Grabmeier-Pfistershammer; Armin Rieger; Michael Kundi; P. Grundtner; Markus Peck-Radosavljevic; T. Popow-Kraupp
The aim of this retrospective study was the identification of clinically useful viral determinants for the prediction of hepatitis B surface antigen (HBsAg) seroclearance and sustained virological response in hepatitis B virus/human immunodeficiency virus (HBV‐/HIV)‐coinfected patients receiving HBV‐active combined antiretroviral therapy (cART). Quantification of HBsAg, HBeAg and HBV DNA before and after initiation of HBV‐active cART in a cohort of 59 HIV‐/HBV‐coinfected patients was performed. Calculations of receiver operating characteristics (ROC) and Kaplan–Meier analysis were used for the identification of predictors of HBsAg seroclearance for HBeAg‐positive [HBeAg(+); n = 36] and HBeAg‐negative [HBeAg(−);n = 23] patients. HBeAg(+) patients with an HBsAg on‐treatment decline ≥1 log IU/mL per year achieved higher HBsAg loss rates (P = 0.0294), whereas the quantification of HBeAg had no predictive value for HBsAg seroclearance. Among HBeAg(−) patients, a pretreatment baseline cut‐off level of HBsAg ≤100 IU/mL was highly predictive for HBsAg seroclearance. No significant influence of the HBV genotype on HBsAg seroclearance was observed among the entire cohort. Quantitative determination of HBsAg provides a clinically useful viral parameter for the prediction of HBsAg seroclearance both in HBeAg(+) and HBeAg(−) HIV‐/HBV‐coinfected patients receiving HBV‐active cART.
Journal of Clinical Virology | 2016
Martina Schneider; Teresa Matiqi; Michael Kundi; Franz J.J. Rieder; Martin Andreas; Robert Strassl; Andreas Zuckermann; Christof Jungbauer; Christoph Steininger
BACKGROUND The toll-like receptor 2 (TLR2) is a significant component of innate immunity against cytomegalovirus (CMV) infection but information on the clinical significance of the single nucleotide polymorphism (SNP) (R753Q) is conflicting. OBJECTIVES The inconsistent observations of the immunological and clinical significance of the TLR2 R753Q polymorphism for CMV infection indicates the influence of confounders. STUDY DESIGN The presence of the TLR2 polymorphism was determined by a genotyping assay of 175 HTX patients and 281 healthy blood donors and evaluated in relation to selected virological and clinical parameters. RESULTS Relative frequency of TLR2 polymorphism was similar in HTX patients and blood donors (homozygous wild-type, 94.3% vs. 94.0%; heterozygous, 5.1% vs. 5.7%; homozygous mutated, <1%). CMV viremia was detectable in 108 (61.7%) of HTX patients. The TLR2 polymorphism was neither associated with occurrence or level of CMV infection nor with survival, graft failure or rejection, or CMV serostatus of patient before transplantation. Nevertheless, CMV viremia occurred in 83.1% of R+/D+, 77.1% of R+/D-, and 64.3% of R-/D+ patients. Time of first CMV viremia was in R-/D+ patients later than in CMV-seropositive patients (median, 182days versus 23 days; P<0.001) corresponding to the duration of antiviral prophylaxis in R-/D+ patients. CONCLUSIONS The TLR2 R753Q polymorphism is extremely rare in the general population and HTX patients. Screening for this risk factor of CMV disease may not be cost-effective in contrast to testing for CMV viremia.
Journal of Hepatology | 2013
Karoline Rutter; Albert Friedrich Stättermayer; Peter Ferenci; Sandra Beinhardt; Thomas-Matthias Scherzer; Robert Strassl; Petra Steindl-Munda; Michael Trauner; Harald Hofer
100% of patients with RV in week 48 maintained undetectable HCVRNA levels at follow-up at 2 and 3 years. 5 of the 6 patients, who relapsed after a week, had received short courses of oral antiviral. Conclusions: The highest percentage of relapses in patients who have received treatment with direct antivirals occurs between week 12 and week 24 of follow-up (50%). The sustained viral response at week 48 (one year post-treatment) remained in 100% of patients during follow-up. The presence of late recurrences may require redefining of the SVR.