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Dive into the research topics where Harald H. Kessler is active.

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Featured researches published by Harald H. Kessler.


Clinical Gastroenterology and Hepatology | 2011

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

Albert Friedrich Stättermayer; Rudolf E. Stauber; Harald Hofer; Karoline Rutter; Sandra Beinhardt; Thomas Matthias Scherzer; Kerstin Zinober; Christian Datz; A Maieron; Emina Dulic–Lakovic; Harald H. Kessler; Petra Steindl–Munda; Michael Strasser; Christoph Krall; Peter Ferenci

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.


Journal of Clinical Microbiology | 2002

Detection of Methicillin-Resistant Staphylococcus aureus and Simultaneous Confirmation by Automated Nucleic Acid Extraction and Real-Time PCR

Andrea J. Grisold; Eva Leitner; Gerhard Mühlbauer; Egon Marth; Harald H. Kessler

ABSTRACT A molecular assay for the simultaneous detection of a Staphylococcus aureus-specific gene and the mecA gene, responsible for the resistance to methicillin in staphylococci, was evaluated. The assay included an automated DNA extraction protocol conducted with a MagNA Pure instrument and real-time PCR conducted with a LightCycler instrument. The performance and robustness of the assay were evaluated for a suspension of methicillin-resistant S. aureus (MRSA) strain with a turbidity equivalent to a McFarland standard of 0.5, which was found to be the ideal working concentration. The specificity of the new molecular assay was tested with a panel of 30 gram-negative and gram-positive bacterial strains other than MRSA. No cross-reactivity was observed. In a clinical study, 109 isolates of MRSA were investigated. All clinical MRSA isolates gave positive results for the S. aureus-specific genomic target, and all but one were positive for the mecA gene. In conclusion, the new molecular assay was found to be quick, robust, and laborsaving, and it proved to be suitable for a routine molecular diagnostic laboratory.


Journal of Hepatology | 2011

Early virologic response and IL28B polymorphisms in patients with chronic hepatitis C genotype 3 treated with peginterferon alfa-2a and ribavirin

Thomas-Matthias Scherzer; Harald Hofer; A.F. Staettermayer; Karoline Rutter; Sandra Beinhardt; Petra Steindl-Munda; Heidrun Kerschner; Harald H. Kessler; Peter Ferenci

BACKGROUND & AIMS Polymorphisms of the IL28B gene (rs12979860 and rs8099917) are associated with high sustained virological response (SVR) rates in HCV genotype 1 patients. This study analyzes the impact of these IL28B polymorphisms on early treatment response (weeks 2 and 4) and SVR in HCV genotype 3 patients. METHODS rs12979860 and rs8099917 were analyzed by the Step-OnePlus Real-time PCR system in 71 out of 72 Caucasian HCV genotype 3 patients participating, at our center, in a randomized study comparing 400mg with 800 mg ribavirin/day. HCV RNA was determined at weeks 2 and 4 of 180 μg/week peginterferon alfa-2a/ribavirin treatment. Sixty-nine patients completed the treatment and follow-up. RESULTS rs12979860 genotyping revealed that 27 (37.5%) patients had C/C, 39 (54.2%) T/C, and 5 (6.9%) T/T. Thirteen patients (18.1%) became HCV RNA negative at week 2 and an additional 30 (41.7%) at week 4 (rapid virologic response; RVR); thus a total of 43 had a RVR (C/C: 77.8%; T/C or T/T: 50.0%). Irrespective of the ribavirin dose, the viral load decline was larger than in those with the T allele (T/C or T/T) (week 2: 4.46; [0.36-6.02] median; [range] vs. 3.50; [0.14-5.62]; log IU HCV-RNA/ml; p<0.001; week 4: 4.97; [1.21-6.20] vs. 4.49; [1.16-6.23]; p=0.003). Despite the faster initial viral response in C/C carriers, SVR rates were not different compared to T-allele carriers. Results of the SNP in the rs8099917 region were similar. CONCLUSIONS IL28B polymorphisms modulate early virologic response to peginterferon/ribavirin treatment. In contrast to HCV genotype 1 patients, no effect on SVR rates was observed in genotype 3 patients. The clinical relevance of an earlier viral decline in C/C patients needs to be determined.


Pediatrics | 2000

Interferon-alpha and ribavirin in treating children and young adults with chronic hepatitis C after malignancy.

Herwig Lackner; Andrea Moser; Johann Deutsch; Harald H. Kessler; Martin Benesch; Reinhold Kerbl; Wolfgang Schwinger; Hans-Jürgen Dornbusch; Karl-Heinz Preisegger; Christian Urban

Objective. Chronic hepatitis C is a major long-term problem for children who survive cancer. Interferon (IFN)-α has been shown to be effective in treating patients with chronic hepatitis C; however, the rate of sustained response is low. Combining IFN-α and ribavirin (RBV) has been shown to significantly improve the response in adult patients with chronic hepatitis C. The aim of this pilot study was to evaluate the efficacy and safety of a combined virostatic treatment with IFN-α and RBV in a small cohort of children and adolescents with chronic hepatitis C and previous malignancy. Methods. Twelve patients with a history of a hematooncologic disease (median follow-up: 13.5 years; range: 7–14.7 years) and chronic hepatitis C were treated with recombinant IFN-α-2a (6 megaunits/m2 body surface area, 3 times a week, subcutaneously) combined with RBV (15 mg/kg body weight/day, orally) for 12 months. They were tested monthly for blood counts and liver function, and for serum virus concentrations (hepatitis C virus RNA by polymerase chain reaction) every 3 months. Results. At the end of the treatment, hepatitis C virus RNA could not be detected in the serum of 8 of the 12 patients; 2 of these patients relapsed soon after therapy withdrawal, whereas 6 patients maintained in sustained virologic and biochemical remission (follow-up: 12 months). Treatment-induced toxicity was moderate and reversible with influenza-like symptoms and a decrease in blood counts in all 12 patients, alopecia in 5 of the 12, hemolysis in 4 of the 12, and weight loss of >10% in 2 of the 12. Conclusions. As demonstrated in adults with chronic hepatitis C, treatment with IFN-α and RBV also seems to be an effective and safe therapeutic option for children and adolescents with chronic hepatitis C after malignancy.


Journal of Clinical Virology | 2003

Parallel detection of five human herpes virus DNAs by a set of real-time polymerase chain reactions in a single run

Markus Stöcher; Victoria Leb; Michael Bozic; Harald H. Kessler; Gabriele Halwachs-Baumann; Olfert Landt; Herbert Stekel; Jörg Berg

BACKGROUND Human herpes viruses cause a spectrum of diseases that are usually self-limiting but can be reactive during immuno-suppression and may then lead to severe or even life-threatening diseases. The LightCycler technology allows rapid polymerase chain reaction (PCR) including product analysis within a closed system. This approach has been demonstrated to be suitable for routine diagnostic virus detection. Several LightCycler PCR assays have been established to the detection of human herpes viruses. The assays vary in their detection formats and PCR cycling protocols. So, they cannot be performed within a single LightCycler run. OBJECTIVES Development of four LightCycler PCR assays for parallel detection of DNA derived from human cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus type 1 (HSV-1), herpes simplex virus type 2 (HSV-2), and varicella-zoster virus (VZV) in a single run. STUDY DESIGN Primers and hybridization probes were tailored to suit one LightCycler PCR program. LightCycler PCRs were established, detection limits were determined, and clinical samples were evaluated. RESULTS With quantified herpes virus type specific DNA spiked into cerebrospinal fluid, serum or EDTA plasma the detection limits were found either at 500 or 250 viral DNA copies per ml depending on the virus DNA specific PCR and on the specimen type used. The applicability of the new LightCycler assays for routine molecular testing was evaluated by testing 96 clinical samples. CONCLUSION The developed set of LightCycler PCRs permits parallel detection of CMV, EBV, HSV-1, HSV-2, and VZV in a single LightCycler run. The new molecular assays can easily be used to the rapid, simple, and convenient detection of herpes virus DNA in cerebrospinal fluid, serum and EDTA plasma in the routine diagnostic laboratory.


Clinical and Diagnostic Virology | 1998

Evaluation of a new assay for HBV DNA quantitation in patients with chronic hepatitis B

Harald H. Kessler; Karen Pierer; Elizabeth A. Dragon; Herwig Lackner; Brigitte I. Santner; Doris Stünzner; Evelyn Stelzl; Brigitte Waitzl; Egon Marth

BACKGROUND The Amplicor HBV Monitor Test for quantitative determination of serum hepatitis B virus (HBV) DNA has recently been introduced. This assay is based on PCR and a non-radioactive hybridization and detection system on microwell plates. OBJECTIVE The performance of the Amplicor HBV Monitor Test was evaluated in a routine diagnostic laboratory. The Amplicor HBV Monoitor assay was compared to the Digene Hybrid Capture System HBV DNA assay for the quantitation of HBV in patient sera. STUDY DESIGN Sensitivity and reproducibility were determined with 10-fold dilution series of two Eurohep HBV reference plasma specimens. Furthermore, 196 sera from 14 children with chronic HBV infection and interferon therapy were tested with both assays. RESULTS The detection limit was found to be 10(3) copies/ml with the Amplicor PCR assay compared to 10(6) to 10(7) copies/ml with the Digene hybridization assay. Both assays were quasi-linear over the measurable ranges. The new PCR assay proved to be very reliable. With the Amplicor PCR assay, 26.2% of the HBV DNA-positive clinical samples were found between 10(3) and 10(7) copies/ml and all of them tested below the detection limit with the hybridization assay. CONCLUSION The Amplicor HBV Monitor Test shows excellent sensitivity and provides a valuable tool for the detection of HBV DNA in serum. It can be used for recognizing those patients who might benefit from antiviral therapy, for evaluation of the efficacy of anti-HBV therapy, and for validation of blood products.


Antimicrobial Agents and Chemotherapy | 2006

Emergence of Enterobacteriaceae isolates producing CTX-M extended-spectrum beta-lactamase in Austria

Alexandra Eisner; Elizabeth J. Fagan; Gebhard Feierl; Harald H. Kessler; Egon Marth; David M. Livermore; Neil Woodford

ABSTRACT Among 149 extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae isolates collected from patients in southeast Austria from 1998 to 2004, 38 Escherichia coli isolates and 11 Klebsiella spp. were CTX-M producers. The proportion of CTX-M-producers among all ESBL producers rose from 0% in 1998 to 58% in 2004. In general, CTX-M-producers had heterogeneous pulsed-field gel electrophoresis patterns, but one E. coli isolate was identical to a United Kingdom epidemic CTX-M-15-producing strain, although no epidemiological link with the United Kingdom was apparent.


Journal of Clinical Virology | 2002

Human cytomegalovirus load in various body fluids of congenitally infected newborns

Gabriele Halwachs-Baumann; Bernd Genser; Sabine Pailer; Heidi Engele; Hellfried Rosegger; Andreas Schalk; Harald H. Kessler; Martie Truschnig-Wilders

BACKGROUND Congenital human cytomegalovirus (hCMV) infection is the most common intrauterine viral disease in western countries. Little is known about hCMV virus load in various body fluids of congenitally infected children. OBJECTIVES To determine virus load in various body fluids. To assess the impact of hCMV virus load to predict the outcome of congenitally infected newborns and efficacy of antiviral therapy. STUDY DESIGN Cord vein blood, urine, and cerebrospinal fluid (CSF) of congenitally hCMV-infected children were investigated and hCMV load was determined by quantitative polymerase chain reaction (PCR). Fourteen of 30 children had clinical symptoms and/or pathological laboratory results and 16 had none of them at birth. Ganciclovir was given to 21 children (10 of them with symptoms, 11 of them without symptoms). Viral load before and after therapy was measured. RESULTS There was a significant difference between median virus load in cord vein blood (2.3 x 10(3) copies per ml) and in urine (4.2 x 10(5) copies per ml; P<0.001) at diagnosis of congenital hCMV infection. At that time, no significant difference of virus load was found between the various groups (symptomatic vs. asymptomatic; with therapy vs. without therapy), neither in serum nor in urine. Comparing median virus load in urine before (3.0 x 10(5) copies per ml) and after therapy (2.0 x 10(3) copies per ml), a significant decrease was observed (P<0.001). Virus load in CSF was always found to be less than 400 copies per ml, and only those children with symptoms showed a positive result. CONCLUSION At birth, virus load in urine seems to be superior to that in cord vein blood to reflect the situation in the organs precisely. As predicting factor for the risk of developing symptoms, only hCMV detection in the CSF appears to be promising. The significant decrease of virus load in children with therapy may reflect the efficacy of therapy. Studies including a greater number of children are needed.


Clinical and Vaccine Immunology | 2000

Identification of Different States of Hepatitis B Virus Infection with a Quantitative PCR Assay

Harald H. Kessler; Sabine Preininger; Evelyn Stelzl; Elisabeth Daghofer; Brigitte I. Santner; Egon Marth; Herwig Lackner; Rudolf E. Stauber

ABSTRACT The level of hepatitis B virus (HBV) DNA in serum reflects the replicative activity of HBV. To compare serum HBV DNA levels in different states of hepatitis B, 47 sera of patients with HBeAg-positive chronic hepatitis B, 4 sera of patients with HBeAg-negative chronic hepatitis B, 40 samples of patients after HBeAg seroconversion during alpha interferon treatment, 57 sera of inactive HBsAg carriers, and 42 sera of patients who had recovered from chronic hepatitis B more than 12 months prior to blood collection were checked for the presence of HBV DNA with the Amplicor HBV Monitor Test. In patients with HBeAg-positive chronic hepatitis B, the median of serum HBV DNA levels (8.3 × 108 copies/ml) was significantly higher than that for patients after HBeAg seroconversion (6.2 × 103 copies/ml) and than that for inactive HBsAg carriers (5.6 × 103 copies/ml). None of the patients who had recovered from hepatitis B had detectable HBV DNA in serum. Quantitative PCR proved to be a valuable tool for identification of different states of HBV infection. This technique was found to be a good method for determination of serum HBV DNA levels both for patients with HBeAg seroconversion and for inactive carriers who showed low viremia not detectable by conventional hybridization assays.


Journal of Clinical Microbiology | 2004

Rapid Quantification of Hepatitis B Virus DNA by Automated Sample Preparation and Real-Time PCR

Evelyn Stelzl; Zsófia Müller; Egon Marth; Harald H. Kessler

ABSTRACT Monitoring of hepatitis B virus (HBV) DNA in serum by molecular methods has become the standard for assessment of the replicative activity of HBV. Several molecular assays for the detection and quantification of HBV DNA have been described. However, they usually lack automated sample preparation. Moreover, those assays, which are based on PCR, are limited by a short dynamic range (2 to 3 log units). In the present study, the use of RealArt HBV LC PCR Reagents in conjunction with automated extraction on the COBAS AMPLIPREP analyzer was evaluated. Members of an HBV proficiency program panel were tested; linearity, interassay, and intra-assay variations were determined. The performance of the assay in a routine clinical laboratory was evaluated with a total of 117 clinical specimens. When members of the HBV proficiency program panel were tested by the new molecular assay, the results were found to be within ±0.5 log unit of the results obtained by reference laboratories. Determination of linearity resulted in a quasilinear curve over more than 6 log units. The interassay variation of the RealArt HBV LC PCR Reagents by use of the automated sample preparation protocol ranged from 16 to 73%, and the intra-assay variation ranged from 9 to 40%. When clinical samples were tested by the new assay with the automated sample preparation protocol and the results were compared with those obtained by the COBAS AMPLICOR HBV MONITOR Test with manual sample preparation, the results for 76% of all samples with positive results by both tests were found to be within ±0.5 log unit and the results for another 18% were found to be within between 0.5 and 1.0 log unit. In conclusion, the real-time PCR assay with automated sample preparation proved to be suitable for the routine molecular laboratory and required less hands-on time.

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Egon Marth

Medical University of Graz

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Evelyn Stelzl

Medical University of Graz

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Rudolf E. Stauber

Medical University of Graz

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Peter Ferenci

Medical University of Vienna

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Eva Leitner

Medical University of Graz

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Herwig Lackner

Medical University of Graz

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