Peter Schlenke

Prof. Dr. Peter Schlenke

Department of Blood Group Serology and Transfusion Medicine, Medical University of Graz, 8036 Graz, Austria
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Research Focus & Metrics

Academic Career Length

28Years (1999-Present)

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

Representative Publications

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1 July 2014 in Transfusion Medicine and Hemotherapy
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Peter SchlenkePeter Schlenke
Peter Schlenke
Nowadays patients receiving blood components are exposed to much less transfusion-transmitted infectious diseases than three decades before when among others HIV was identified as causative agent for the acquired immunodeficiency syndrome and the transmission by blood or coagulation factors became evident. Since that time the implementation of measures for risk prevention and safety precaution was socially and politically accepted. Currently emerging pathogens like arboviruses and the well-known bacterial contamination of platelet concentrates still remain major concerns of blood safety with important clinical consequences, but very rarely with fatal outcome for the blood recipient. In contrast to the well-established pathogen inactivation strategies for fresh frozen plasma using the solvent-detergent procedure or methylene blue and visible light, the bench-to-bedside translation of novel pathogen inactivation technologies for cell-containing blood components such as platelets and red blood cells are still underway. This review summarizes the pharmacological/toxicological assessment and the inactivation efficacy against viruses, bacteria, and protozoa of each of the currently available pathogen inactivation technologies and highlights the impact of the results obtained from several randomized clinical trials and hemovigilance data. Until now in some European countries pathogen inactivation technologies are in in routine use for single-donor plasma and platelets. The invention and adaption of pathogen inactivation technologies for red blood cell units and whole blood donations suggest the universal applicability of these technologies and foster a paradigm shift in the manufacturing of safe blood.

29 August 2022 in Journal of Clinical Medicine
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Journal Article
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KZKatharina Zwittnig
Katharina Zwittnig
BKBarbara Kirnbauer
Barbara Kirnbauer
NJNorbert Jakse
Norbert Jakse
Peter SchlenkePeter Schlenke
Peter Schlenke
IMIrene Mischak
Irene Mischak
TZTomislav Zrnc
Tomislav Zrnc
Aim: The purpose of this study was to obtain data concerning growth factor release within liquid and solid platelet-rich fibrin (PRF) matrices and to estimate the amount of potential interindividual variations as a basis for further preclinical and clinical trials. Therefore, we aimed to determine possible differences in the release of growth factors between liquid and solid PRF. Materials and Methods: Blood samples obtained from four subjects were processed to both liquid and solid PRF matrices using a standard centrifugation protocol. Five growth factors (vascular endothelial growth factor, VEGF; epidermal growth factor, EGF; platelet-derived growth factor-BB, PDGF-BB; transforming growth factor-β1, TGF-β1; and matrix metallopeptidase 9, MMP-9) have been evaluated at six time points by ELISA over a total observation period of 10 days (1 h, 7 h, 1 d, 2 d, 7 d, and 10 d). Results: Growth factor release could be measured in all samples at each time point. Comparing liquid and solid PRF matrices, no significant differences were detected (p > 0.05). The mean release of VEGF, TGFβ-1, PDGF-BB, and MMP-9 raised to a peak at time point five (day 7) in both liquid and solid PRF matrices. VEGF release was lower in liquid PRF than in solid PRF, whereas those of PDGF-BB and MMP-9 were higher in liquid PRF than in solid PRF at all time points. EGF had its peak release already at time point two after 7 h in liquid and solid matrices (hour 7 EGF solid: mean = 180 pg/mL, SD = 81; EGF liquid: mean = 218 pg/mL, SD = 64), declined rapidly until day 2, and had a second slight peak on day 7 in both groups (day 7 EGF solid: mean = 182 pg/mL, SD = 189; EGF liquid: mean = 81 pg/mL, SD = 70). Conclusions: This study detected growth factor release within liquid and solid PRF matrices with little variations. Further preclinical trials are needed to precisely analyze the growth factor release in larger samples and to better understand their effects on wound healing in different clinical indications.

5 May 2020 in Nutrients
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SMSusanne Macher
Susanne Macher
CHCornelia Herster
Cornelia Herster
MHMagdalena Holter
Magdalena Holter
MMMartina Moritz
Martina Moritz
EMEva Maria Matzhold
Eva Maria Matzhold
Karin AmreinKarin Amrein
Karin Amrein
Background: Besides anemia, iron deficiency may cause more subtle symptoms, including the restless legs syndrome (RLS), the chronic fatigue syndrome (CFS) or sleeping disorders. Objective: The aim of this pre-planned secondary analysis of the IronWoMan randomized controlled trial (RCT) was to compare the frequency and severity of symptoms associated with iron deficiency before and after (intravenous or oral) iron supplementation in iron deficient blood donors. Methods/Design: Prospective, randomized, controlled, single-centre trial. (ClinicalTrials.gov: NCT01787526). Setting: Tertiary care center in Graz, Austria. Participants: 176 (138 female and 38 male) whole-blood and platelet apheresis donors aged ≥ 18 and ≤ 65 years with iron deficiency (ferritin ≤ 30ng/mL at the time of blood donation). Interventions: Intravenous iron (1 g ferric carboxymaltose, n = 86) or oral iron supplementation (10 g iron fumarate, 100 capsules, n = 90). Measurements: Clinical symptoms were evaluated by a survey before iron therapy (visit 0, V0) and after 8–12 weeks (visit 1, V1), including questions about symptoms of restless legs syndrome (RLS), chronic fatigue syndrome (CFS), sleeping disorders, quality of life and symptoms like headaches, dyspnoea, dizziness, palpitations, pica and trophic changes in fingernails or hair. Results: We found a significant improvement in the severity of symptoms for RLS, fatigue and sleep quality (p < 0.001). Furthermore, a significant decrease in headaches, dyspnoea, dizziness and palpitations was reported (p < 0.05). There was no difference between the type of iron supplementation (intravenous versus oral) and clinical outcome data. Conclusion: Iron supplementation in iron-deficient blood donors may be an effective strategy to improve symptoms related to iron deficiency and the wellbeing of blood donors.

22 December 2022 in Transfusion Medicine and Hemotherapy
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Journal Article
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KZKatharina Zwittnig
Katharina Zwittnig
KMKhaled Mukaddam
Khaled Mukaddam
Daniel VeghDaniel Vegh
Daniel Vegh
Valentin HerberValentin Herber
Valentin Herber
NJNorbert Jakse
Norbert Jakse
MPMichael Payer
Michael Payer
Background: The application of blood concentrates has gained popularity in dentistry in recent years. Platelet-rich fibrin (PRF) has been discussed frequently due to a high content of growth factors and the option of chair-side manufacturing in a simple centrifugation process. PRF is free from adjuvants and inexpensive to produce. The number of studies reporting beneficial effects of PRF in various clinical applications such as alveolar ridge preservation, sinus floor elevation, management and prevention of medical-related osteonecrosis of the jaw, third molar extractions, and guided bone regeneration in dentistry has increased recently. However, to date, neither clinical recommendations nor guidelines are available. The present narrative review aims to summarize the level of evidence on the clinical application of PRF within the field of oral surgery and implantology. Summary: A literature search in Pubmed and Medline has identified 34 articles as a basis for this narrative review. The effectiveness of the clinical application of PRF has been analyzed for five indications within dentistry: medical-related osteonecrosis of the jaw, wisdom tooth extraction, guided bone regeneration, sinus floor elevation, and alveolar ridge preservation. The amount of data for third molar extractions, socket preservation, and guided bone regeneration is extensive. Less data were available for the use of PRF in combination with sinus floor elevations. There is a lack of studies with scientific evidence on PRF and medical-related osteonecrosis of the jaw; however, studies positively impact patient-related outcome measures. Most studies report on beneficial effects when PRF is additionally applied in intrabony defects. There is no evidence of the positive effects of PRF combined with bone graft materials during sinus floor elevation. However, some benefits are reported with PRF as a sole filling material. Key Messages: Many recently published studies show the positive clinical impact of PRF. Yet, further research is needed to ensure the validity of the evidence.

1 March 2020 in Clinical Nutrition
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Journal Article
Open access
CDCamilla Drexler
Camilla Drexler
SMSusanne Macher
Susanne Macher
ILInes Lindenau
Ines Lindenau
MHMagdalena Holter
Magdalena Holter
MMMartina Moritz
Martina Moritz
Karin AmreinKarin Amrein
Karin Amrein
Frequent blood donation often leads to iron deficiency and even anemia but appropriate strategies for detection and prevention are currently not mandatory. At the Medical University of Graz, we conducted a single-center prospective clinical trial to compare oral and IV iron supplementation in iron deficient blood donors including Austrian regular whole blood and platelet apheresis donors. We aimed to determine the difference of transferrin saturation between the treatment groups 8-12 weeks iron administration besides other parameters of iron status and blood count. 176 healthy male and female blood donors with iron deficiency (ferritin ≤30 ng/mL) were randomized to either a single dose of IV ferric carboxymaltose (1000 mg, n = 86) or oral iron (II)fumarate (100 tablets of 100 mg [10 per week], n = 90). Between 2014 and 2016, 172 donors (137 women) completed the study; 4 in the oral group were lost to follow-up. At follow-up, median (IQR) transferrin saturation and ferritin were significantly higher in the intravenous group (27 [23-35]%, vs 21.0 [16-32]%; p < 0.001 and 105 [75-145] ng/mL vs 25 [17-34] ng/mL; p < 0.001, respectively) while median (IQR) hemoglobin levels were comparable (IV, 13.6 [13.0-14.4] g/dL vs oral, 13.6 [13.0-14.2] g/dL). The frequency of adverse effects was comparable (38% in both groups) and no serious adverse events occurred. A single dose of 1000 mg of intravenous iron is highly effective to counteract iatrogenic iron deficiency in blood donors. Oral iron appears to be an acceptable alternative. The assessment of body iron stores should play a key role in maintaining blood donors' health. This trial was registered at www.clinicaltrials.gov as NCT01787526 on February 8, 2013 and at www.clinicaltrialsregister.eu (EudraCT identifier: 2013-000327-14) on September 24, 2013.

4 March 2021 in Cells
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Journal Article
Open access
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CBClaudia Bernecker
Claudia Bernecker
MLMARIA AUGUSTA do Rego Barros Fernandes Lima
MARIA AUGUSTA do Rego Barros Fernandes Lima
CCCatalin D. Ciubotaru
Catalin D. Ciubotaru
Peter SchlenkePeter Schlenke
Peter Schlenke
IDIsabel Dorn
Isabel Dorn
Ddan CojocDdan Cojoc
Ddan Cojoc
Ex vivo-generated red blood cells are a promising resource for future safe blood products, manufactured independently of voluntary blood donations. The physiological process of terminal maturation from spheroid reticulocytes to biconcave erythrocytes has not been accomplished yet. A better biomechanical characterization of cultured red blood cells (cRBCs) will be of utmost interest for manufacturer approval and therapeutic application. Here, we introduce a novel optical tweezer (OT) approach to measure the deformation and elasticity of single cells trapped away from the coverslip. To investigate membrane properties dependent on membrane lipid content, two culture conditions of cRBCs were investigated, cRBCPlasma with plasma and cRBCHPL supplemented with human platelet lysate. Biomechanical characterization of cells under optical forces proves the similar features of native RBCs and cRBCHPL, and different characteristics for cRBCPlasma. To confirm these results, we also applied a second technique, digital holographic microscopy (DHM), for cells laid on the surface. OT and DHM provided related results in terms of cell deformation and membrane fluctuations, allowing a reliable discrimination between cultured and native red blood cells. The two techniques are compared and discussed in terms of application and complementarity.