Matthias G. Vossen

Dr. Matthias G. Vossen

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Research Focus & Metrics

Academic Career Length

20Years (2007-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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5 April 2018 in Clinical Infectious Diseases
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Journal Article
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STSelma Tobudic
Selma Tobudic
Christina BahrsChristina Bahrs
Christina Bahrs
HBHeinz Burgmann
Heinz Burgmann
HLHeimo Lagler
Heimo Lagler
Michael RamharterMichael Ramharter
Michael Ramharter
FTFlorian Thalhammer
Florian Thalhammer
The clinical outcomes and safety of dalbavancin as primary and sequential treatment of gram-positive bacteremia with infective endocarditis were evaluated retrospectively. The clinical success rate was high (92.6%), but in 24 of 27 patients dalbavancin was used only after clearance of bacteria from the bloodstream.

11 July 2018 in The Journal of Infectious Diseases
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RSRobert Strassl
Robert Strassl
MSMartin Schiemann
Martin Schiemann
KDKonstantin Doberer
Konstantin Doberer
IGIrene Görzer
Irene Görzer
EPElisabeth Puchhammer-Stöckl
Elisabeth Puchhammer-Stöckl
GBGregor Bond
Gregor Bond
Drug-induced immunosuppression following kidney transplantation is crucial to prevent allograft rejection, but increases risk for infectious disease. Tailoring of drug dosing to prevent both rejection and infection is greatly desirable. The apathogenic and ubiquitous torque teno virus (TTV) reflects immunocompetence of the host and might be a potential candidate for immunologic monitoring. To assess TTV as an infection biomarker, virus load was prospectively quantified in peripheral blood of 169 consecutive renal allograft recipients at the Medical University Vienna. Patients with infection showed higher TTV levels compared to patients without infection (4.2 × 108 copies/mL [interquartile range, IQR, 2.7 × 107–1.9 × 109] vs 2.9 × 107 [IQR 1.0 × 106–7.2 × 108]; P = .006). Differences in TTV load became evident almost 3 months before infection (median 77 days, IQR 19–98). Each log level of TTV copies/mL increased the odds ratio for infection by 23% (95% confidence interval 1.04–1.45; P = .014). TTV >3.1 × 109 copies/mL corresponded to 90% sensitivity to predict infections. Logistic regression demonstrated independent association between TTV levels and infection. TTV quantification predicts infection after kidney transplantation and might be a potential tool to tailor immunosuppressive drug therapy.

22 March 2023 in Trials
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FHFrederik Haupenthal
Frederik Haupenthal
JRJette Rahn
Jette Rahn
FMFabrizio Maggi
Fabrizio Maggi
FGFanny Gelas
Fanny Gelas
PBPhilippe Bourgeois
Philippe Bourgeois
SOSophie Ohlmann
Sophie Ohlmann
Background: Immunosuppression after kidney transplantation is mainly guided via plasma tacrolimus trough level, which cannot sufficiently predict allograft rejection and infection. The plasma load of the non-pathogenic and highly prevalent torque teno virus (TTV) is associated with the immunosuppression of its host. Non-interventional studies suggest the use of TTV load to predict allograft rejection and infection. The primary objective of the current trial is to demonstrate the safety, tolerability and preliminary efficacy of TTV-guided immunosuppression. Methods: For this purpose, a randomised, controlled, interventional, two-arm, non-inferiority, patient- and assessor-blinded, investigator-driven phase II trial was designed. A total of 260 stable, low-immunological-risk adult recipients of a kidney graft with tacrolimus-based immunosuppression and TTV infection after month 3 post-transplantation will be recruited in 13 academic centres in six European countries. Subjects will be randomised in a 1:1 ratio (allocation concealment) to receive tacrolimus either guided by TTV load or according to the local centre standard for 9 months. The primary composite endpoint includes the occurrence of infections, biopsy-proven allograft rejection, graft loss, or death. The main secondary endpoints include estimated glomerular filtration rate, graft rejection detected by protocol biopsy at month 12 post-transplantation (including molecular microscopy), development of de novo donor-specific antibodies, health-related quality of life, and drug adherence. In parallel, a comprehensive biobank will be established including plasma, serum, urine and whole blood. The date of the first enrolment was August 2022 and the planned end is April 2025. Discussion: The assessment of individual kidney transplant recipient immune function might enable clinicians to personalise immunosuppression, thereby reducing infection and rejection. Moreover, the trial might act as a proof of principle for TTV-guided immunosuppression and thus pave the way for broader clinical applications, including as guidance for immune modulators or disease-modifying agents. Trial registration: EU CT-Number: 2022-500024-30-00

4 July 2024 in Blood
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RBRaffaele Badolato
Raffaele Badolato
LALaia Alsina
Laia Alsina
AAAntoine Azar
Antoine Azar
YBYves Bertrand
Yves Bertrand
ABAudrey A. Bolyard
Audrey A. Bolyard
JDJean Donadieu
Jean Donadieu
We investigated efficacy and safety of mavorixafor, an oral CXCR4 antagonist, in participants with warts, hypogammaglobulinemia, infections, and myelokathexis (WHIM) syndrome, a rare immunodeficiency caused by CXCR4 gain-of-function variants. This randomized (1:1), double-blind, placebo-controlled, phase 3 trial enrolled participants aged ≥12 years with WHIM syndrome and absolute neutrophil count (ANC) ≤0.4 × 103/μL. Participants received once-daily mavorixafor or placebo for 52 weeks. The primary end point was time (hours) above ANC threshold ≥0.5 × 103/μL (TATANC; over 24 hours). Secondary end points included TAT absolute lymphocyte count ≥1.0 × 103/μL (TATALC; over 24 hours); absolute changes in white blood cell (WBC), ANC, and absolute lymphocyte count (ALC) from baseline; annualized infection rate; infection duration; and total infection score (combined infection number/severity). In 31 participants (mavorixafor, n = 14; placebo, n = 17), mavorixafor least squares (LS) mean TATANC was 15.0 hours and 2.8 hours for placebo (P < .001). Mavorixafor LS mean TATALC was 15.8 hours and 4.6 hours for placebo (P < .001). Annualized infection rates were 60% lower with mavorixafor vs placebo (LS mean 1.7 vs 4.2; nominal P = .007), and total infection scores were 40% lower (7.4 [95% confidence interval [CI], 1.6-13.2] vs 12.3 [95% CI, 7.2-17.3]). Treatment with mavorixafor reduced infection frequency, severity, duration, and antibiotic use. No discontinuations occurred due to treatment-emergent adverse events (TEAEs); no related serious TEAEs were observed. Overall, mavorixafor treatment demonstrated significant increases in LS mean TATANC and TATALC, reduced infection frequency, severity/duration, and was well tolerated. The trial was registered at www.clinicaltrials.gov as #NCT03995108.

1 March 2010 in The American Journal of Tropical Medicine and Hygiene
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Journal Article
Closed access
MVMatthias G. Vossen
Matthias G. Vossen
SPSandra Pferschy
Sandra Pferschy
PCPeter Chiba
Peter Chiba
HNHarald Noedl
Harald Noedl
Validation of the sensitivity of the SYBR Green I in vitro test against an enzyme-linked immunosorbent assay (ELISA)-based drug sensitivity assay. Our results suggest that the SYBR Green I assay is a fast and inexpensive malaria drug screening assay for laboratory use. However, because of its lack of sensitivity in whole blood samples its usefulness for testing clinical samples may be limited.

10 April 2022 in Journal of Fungi
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CHClaudia Honsig
Claudia Honsig
BSBrigitte Selitsch
Brigitte Selitsch
MHMarlene Hollenstein
Marlene Hollenstein
MVMatthias G. Vossen
Matthias G. Vossen
KSKathrin Spettel
Kathrin Spettel
Birgit WillingerBirgit Willinger
Birgit Willinger
Invasive infections caused by filamentous fungi constitute a leading cause of morbidity and mortality in immunocompromised patients. Rapid and reliable identification of filamentous fungi is essential for the early initiation of appropriate treatment. In the present study, 230 filamentous fungi isolates identified by conventional methods were investigated using MALDI-TOF MS (Bruker Daltonics, Bremen, Germany) in combination with the Filamentous Fungi Library 3.0 provided by the manufacturer. Three different sample preparation methods were applied as recommended by the manufacturer and identification rates were compared using the criteria provided by the manufacturer. Application of the more time-consuming sample preparation methods clearly improved identification at the species level. Thus, the identification rate increased from 48.9% using the simplest method to 76.1% with the most laborious procedure. Misidentifications did not occur. Furthermore, the reliability of an in-house threshold for species identification was investigated. The reduced threshold increased the rate of isolates correctly identified at the species level by up to 86.4%. As no misidentification was made at the genus level and only one misidentification of minor significance occurred at the species level, this threshold could be validated for routine use in our laboratory. In conclusion, regarding the high identification rates achieved, this commercial platform proved suitable for implementation in routine diagnosis.