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Geisen C, Fleck E, Schäfer SMG, Walter C, Braeuninger S, Jensen JS, Sheridan D, Patki K, Armstrong R, Skogen B, Behrens F, Seifried E, Kjeldsen-Kragh J, Kjær M, Köhm M. A Phase 1b PK/PD Study to Demonstrate Antigen Elimination with RLYB212, a Monoclonal Anti-HPA-1a Antibody for FNAIT Prevention. Thromb Haemost 2024. [PMID: 39168139 DOI: 10.1055/a-2398-9344] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/23/2024]
Abstract
BACKGROUND Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a rare bleeding disorder of the fetus/newborn caused by development of maternal alloantibodies against fetal human platelet antigens (HPAs), predominantly HPA-1a. Currently there are no treatments available to prevent maternal alloimmunization to HPAs or FNAIT. METHODS This proof-of-concept study (EudraCT Number: 2021-005380-49) was designed to assess the ability of subcutaneous (SC) RLYB212, a monoclonal anti-HPA-1a antibody, to eliminate HPA-1a-positive platelets in an antigen challenge model of a 30 mL fetal-maternal hemorrhage. Subjects were randomized to receive a single SC dose of RLYB212 or placebo on day 1 in a single-blinded manner, followed by transfusion of 10 × 109 HPA-1a-positive platelets on day 8. RESULTS Four subjects received 0.09 mg SC RLYB212, five received 0.29 mg SC RLYB212, and two received placebo. RLYB212 achieved rapid elimination of HPA-1a-positive platelets in a concentration-dependent manner, with concentrations as low as 3.57 ng/mL meeting the prespecified proof-of-concept criterion of ≥90% reduction in platelet elimination half-life versus placebo. Following HPA-1a-positive platelet transfusion, a rapid decline was observed in the concentration of RLYB212 over a period of 2 to 24 hours, corresponding to the time needed for RLYB212 to bind to ∼10% of HPA-1a on cell surfaces. RLYB212 was well tolerated with no reports of drug-related adverse events. CONCLUSION The data from this study are consistent with preclinical efficacy data and support the potential use of RLYB212 as a prophylactic treatment for FNAIT that prevents maternal HPA-1a alloimmunization during at-risk pregnancies.
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Affiliation(s)
- Christof Geisen
- Institute of Transfusion Medicine and Immunohaematology, German Red Cross Blood Transfusion Service Baden-Württemberg-Hessen GmbH, Frankfurt am Main, Germany
| | - Erika Fleck
- Institute of Transfusion Medicine and Immunohaematology, German Red Cross Blood Transfusion Service Baden-Württemberg-Hessen GmbH, Frankfurt am Main, Germany
| | - Stephan Martin Gastón Schäfer
- Division Clinical Research, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt am Main, Germany
| | - Carmen Walter
- Division Clinical Research, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt am Main, Germany
| | - Susanne Braeuninger
- Institute of Transfusion Medicine and Immunohaematology, German Red Cross Blood Transfusion Service Baden-Württemberg-Hessen GmbH, Frankfurt am Main, Germany
| | | | | | - Kiran Patki
- Rallybio, New Haven, Connecticut, United States
| | | | - Bjørn Skogen
- Department of Laboratory Medicine, University Hospital of North Norway, Tromsø, Norway
| | - Frank Behrens
- Division Clinical Research, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt am Main, Germany
- Division of Rheumatology, University Hospital Goethe-University Frankfurt am Main, Germany
- Fraunhofer Cluster of Excellence Immune-Mediated Diseases CIMD, Frankfurt am Main, Germany
| | - Erhard Seifried
- Institute of Transfusion Medicine and Immunohaematology, German Red Cross Blood Transfusion Service Baden-Württemberg-Hessen GmbH, Frankfurt am Main, Germany
| | - Jens Kjeldsen-Kragh
- Department of Laboratory Medicine, University Hospital of North Norway, Tromsø, Norway
- Department of Clinical Immunology and Transfusion Medicine, Office for Medical Services, Region Skåne, Lund, Sweden
| | - Mette Kjær
- Faculty of Health Sciences, UiT-The Arctic University of Norway, Hammerfest, Norway
- Finnmark Hospital Trust, Hammerfest, Norway
| | - Michaela Köhm
- Division Clinical Research, Fraunhofer Institute for Translational Medicine and Pharmacology ITMP, Frankfurt am Main, Germany
- Division of Rheumatology, University Hospital Goethe-University Frankfurt am Main, Germany
- Fraunhofer Cluster of Excellence Immune-Mediated Diseases CIMD, Frankfurt am Main, Germany
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2
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Karlström C, Gryfelt G, Schmied L, Meinke S, Höglund P. Platelet transfusion improves clot formation and platelet function in severely thrombocytopenic haematology patients. Br J Haematol 2021; 196:224-233. [PMID: 34528253 DOI: 10.1111/bjh.17820] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2021] [Revised: 08/20/2021] [Accepted: 08/23/2021] [Indexed: 12/16/2022]
Abstract
Prophylactic platelet (PLT) transfusion is a common practice in severely thrombocytopenic patients that reduces mortality, but responses to platelet transfusions are variable and difficult to predict in individual patients. In this prospective study, we evaluated the outcome of PLT transfusions in 40 patients with haematological malignancies, linking corrected count increment (CCI) to clot formation and agonist-induced platelet activation after transfusion. The CCI was highly variable between patients and 34% showed no response (1-h CCI < 7,5). Short time since the last PLT transfusion and extended storage time of the PLT product were linked to poor transfusion response, while patient sex, C-reactive protein or the number of chemotherapy cycles prior to transfusion did not influence transfusion outcome. High CCI and good PLT responsiveness to agonist stimulation predicted efficient clot formation in rotational thromboelastometry, but transfusion did not restore poor PLT function in patients to the level of healthy controls. Our study provides new insights into factors affecting PLT transfusion outcome in haematology patients with severe thrombocytopenia, and suggests that the thrombocytopenic environment, or disease-associated factors, may hamper platelet responsiveness.
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Affiliation(s)
- Cecilia Karlström
- Department of Medicine Huddinge, Center for Haematology and Regenerative Medicine (HERM), Karolinska Institutet, Stockholm, Sweden.,Medical Unit Haematology, Karolinska University Hospital, Stockholm, Sweden
| | - Gunilla Gryfelt
- Medical Unit Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Stockholm, Sweden
| | - Laurent Schmied
- Department of Medicine Huddinge, Center for Haematology and Regenerative Medicine (HERM), Karolinska Institutet, Stockholm, Sweden
| | - Stephan Meinke
- Department of Medicine Huddinge, Center for Haematology and Regenerative Medicine (HERM), Karolinska Institutet, Stockholm, Sweden
| | - Petter Höglund
- Department of Medicine Huddinge, Center for Haematology and Regenerative Medicine (HERM), Karolinska Institutet, Stockholm, Sweden.,Medical Unit Clinical Immunology and Transfusion Medicine, Karolinska University Hospital, Stockholm, Sweden
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3
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Böhmert S, Kübel S, Müller MM, Weber CF, Adam EH, Dröse S, Zacharowski K, Fischer D. The effect of the interruption of agitation, temporary cooling, and pneumatic tube transportation on platelet quality during storage for transfusion. Transfusion 2020; 61:1258-1265. [PMID: 33349943 DOI: 10.1111/trf.16223] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2020] [Revised: 10/05/2020] [Accepted: 11/15/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Conditions during blood product storage and transportation should maintain quality. The aim of this in vitro study was to investigate the effect of interruption of agitation, temporary cooling (TC), and pneumatic tube system transportation (PTST) on the aggregation ability (AA) and mitochondrial function (MF) of platelet concentrates (PC). STUDY DESIGN AND METHODS A PC was divided equally into four subunits and then allocated to four test groups. The control group (I) was stored as recommended (continuous agitation, 22 ± 2°C) for 4 days. The test groups were stored without agitation (II), stored as recommended, albeit 4°C for 60 minutes on day (d)2 (III) and PTST (IV). Aggregometry was measured using Multiplate (RocheAG; ADPtest, ASPItest, TRAPtest, COLtest) and MF using Oxygraph-2k (Oroboros Instruments). The basal and maximum mitochondrial respiratory rate (MMRR) were determined. AA and MF were measured daily in I and II and AA in III and IV on d2 after TC/PTST. Statistical analysis was performed using tests for matched observations. RESULTS Eleven PCs were used. TRAP-6 induced AA was significantly lower in II when compared to I on d4 (P = 0.015*). In III the ASPItest was significantly lower (P = 0.032*). IV showed no significant differences. The basal and MMRR were significantly reduced over 4 days in I and II (for both rates in both groups: P = <0.0001*). No significant differences occurred on d4 (P = 0.495). CONCLUSION Our results indicate that ex vivo AA and MF of PCs are unaffected, even in no-ideal storage and transport circumstances with respect to agitation, temperature, and force.
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Affiliation(s)
- Stephanie Böhmert
- Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Sarah Kübel
- Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Markus Matthias Müller
- German Red Cross Blood Transfusion Service of Baden-Wuerttemberg - Hessen, Institute of Transfusion Medicine and Immunohematology; University Hospital of Frankfurt, Frankfurt, Germany
| | - Christian Friedrich Weber
- Department of Anaesthesiology, Intensive Care and Emergency Medicine, Asklepios Clinic Wandsbek, Hamburg, Germany
| | - Elisabeth Hannah Adam
- Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Stefan Dröse
- Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Kai Zacharowski
- Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
| | - Dania Fischer
- Department of Anaesthesiology, Intensive Care Medicine and Pain Therapy, University Hospital Frankfurt, Goethe University, Frankfurt, Germany
- Department of Anaesthesiology, Heidelberg University Hospital, Heidelberg, Germany
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4
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Eltrombopag for Delayed Platelet Recovery and Secondary Thrombocytopenia Following Allogeneic Stem Cell Transplantation in Children. J Pediatr Hematol Oncol 2019; 41:38-41. [PMID: 30080752 DOI: 10.1097/mph.0000000000001263] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The delay in platelet recovery after hematopoietic stem cell transplantation (HSCT) is closely related to the overall survival rate of transplanted children. The use of platelet-producing agents such as eltrombopag and romiplostim has made great progress in treating diseases such as immune thrombocytopenia and aplastic anemia. However, the use of such drugs in patients with thrombocytopenia after transplantation, especially in children, is rare. This study aimed to report eltrombopag treatment for 3 children with primary platelet engraftment failure and secondary thrombocytopenia after allogeneic HSCT. Of these patients, 2 had platelets stabilized at ≥50×10/L after eltrombopag treatment and subsequent withdrawal of eltrombopag. All 3 patients showed no clear adverse reactions. The results indicated a wide application prospect of eltrombopag treatment in children with thrombocytopenia after allogeneic HSCT.
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5
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Asmis L, Moldenhauer A, Hitzler W, Hellstern P. Comparison of platelet function tests for the in vitro quality assessment of platelet concentrates produced under real-life conditions. Platelets 2018; 30:720-727. [PMID: 30204045 DOI: 10.1080/09537104.2018.1513471] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Platelet quality in different platelet concentrates (PCs) has been the subject of several studies. Nonetheless, there is a lack of robust data on the correlation and agreement among platelet function tests as a prerequisite for the association of PC functionality in vitro with platelet function in vivo post PC transfusion. The purpose of our study was to correlate a larger panel of platelet function assays in PCs and to assess whether the methods agree sufficiently and can be used interchangeably. Twelve apheresis platelet concentrates in plasma (APC), 16 pooled platelet concentrates in plasma (PPC), and 12 PPC in T-sol (PPCA) were examined on days 1 and 4 after production. PCs were tested for platelet count, light transmission aggregation (LTA) induced by ADP, collagen, or TRAP; platelet ATP release induced by collagen; and spontaneous and ADP and TRAP-induced increase in CD62P and PAC1 expression measured by flow cytometry. All tests were performed in undiluted platelet-rich plasma, recalcified and mixed with an inhibitor of factor Xa and thrombin. Most platelet function parameters correlated significantly with each other, but agreement among methods was insufficient. A proper inverse correlation was observed between ADP-induced LTA and spontaneous platelet activation assessed by CD62P expression (r = -0.61, p < 0.0001). Spontaneous CD62P correlated also significantly with spontaneous PAC1 (r = 0.69, p < 0.0001) and inversely with TRAP-induced CD62P expression (r = -0.86, p < 0.0001). We found significant correlations among all flow cytometric assays measuring platelet CD62P and PAC1 expression induced by ADP or TRAP. Subsequent Bland Altman analysis revealed insufficient agreement between methods. With one exception (collagen-induced LTA compared with TRAP-induced LTA, percentage error = 16%) the limits of agreement expressed as percentage error exceeded the chosen acceptable difference of 30%. In APC, platelet count was 41% and 44% higher, respectively, than in PPC and PPCA (p < 0.0001). Spontaneous CD62P and PAC1 expression were significantly greater, and ADP-induced aggregation and agonist-induced increase in CD62P and PAC1 were significantly lower in PPCA compared to APC and PPC on day 4 of storage. ADP and TRAP-induced CD62P and PAC1 activatability fell significantly during storage between day 1 and day 4 in APC and PPCA, but not in PPC. In conclusion, different platelet function tests capture different aspects of platelet function and do not correlate and agree sufficiently to be used interchangeably.
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Affiliation(s)
- Lars Asmis
- a Center of Perioperative Thrombosis and Hemostasis , Zurich , Switzerland
| | - Anja Moldenhauer
- b Institute of Laboratory Diagnostics, Hygiene and Transfusion Medicine , Academic City Hospital , Ludwigshafen , Germany
| | - Walter Hitzler
- c Transfusion Center , University Medical Center of the Johannes Gutenberg University , Mainz , Germany
| | - Peter Hellstern
- d Center of Hemostasis and Thrombosis Zurich , Zurich , Switzerland
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Doescher A, Casper J, Kraemer D, Kapels HH, Petershofen EK, Müller TH. Platelet engraftment after allogenic stem cell transplantation is monitored by digital polymerase chain reaction without interference by platelet support. Exp Hematol 2018; 68:21-29. [PMID: 30195456 DOI: 10.1016/j.exphem.2018.08.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2018] [Revised: 08/20/2018] [Accepted: 08/29/2018] [Indexed: 11/16/2022]
Abstract
Platelet engraftment after allogeneic hematopoietic stem cell transplantation is conventionally monitored by daily platelet counts. Platelet transfusions are frequently required and obscure the detection of platelet engraftment. Digital polymerase chain reaction (ddPCR) of mitochondrial DNA isolated from platelets reliably quantifies circulating platelets derived from the stem cell graft and allows us to distinguish them from transfused single-donor apheresis platelets. In a feasibility study, consecutive daily peripheral blood samples from day 7 to day 20 after transplantation were analyzed by ddPCR in 22 patients after allogeneic transplantation. Platelet engraftment according to ddPCR was defined as the third of at least 3 consecutive days of increasing levels exceeding 1000/µL endogenous platelets. Platelet counts were also assessed according to the engraftment cri`teria of the Center for International Blood & Marrow Transplant Research (CIBMTR) and the European Society for Blood and Marrow Transplantation (EBMT). Out of the 22 patients, five did not achieve platelet engraftment within 20 days by any of the predefined criteria. A subgroup of nine patients did show platelet engraftment by all three definitions. In five patients, engraftment was detectable according to ddPCR and EBMT, whereas in three patients, platelet engraftment within 20 days was only confirmed by ddPCR. The detailed findings suggest that the day of platelet engraftment according to the EBMT criteria closely reflected the ddPCR detection of transplantation-derived platelets. The results from this feasibility study demonstrate that ddPCR offers a sensitive approach to detect platelet engraftment reliably and without interference from the individual noise of platelet counts due to platelet transfusions.
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Affiliation(s)
- Andrea Doescher
- DRK-Blutspendedienst NSTOB, Institut Bremen-Oldenburg, Oldenburg, Germany;.
| | - Jochen Casper
- Universitätsklinik für Innere Medizin II, Onkologie und Hämatologie, Oldenburg, Germany
| | - Doris Kraemer
- Universitätsklinik für Innere Medizin II, Onkologie und Hämatologie, Oldenburg, Germany
| | | | | | - Thomas H Müller
- DRK-Blutspendedienst NSTOB, Institut Springe, Springe, Germany
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7
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Digital PCR to assess platelet recovery after stem cell transplantation. Bone Marrow Transplant 2018; 53:1586-1588. [PMID: 29884855 DOI: 10.1038/s41409-018-0238-x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2018] [Revised: 04/17/2018] [Accepted: 05/03/2018] [Indexed: 11/09/2022]
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8
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Benediktsson S, Lazarevic V, Nilsson L, Kjeldsen-Kragh J, Schött U, Kander T. Linear decline of corrected platelet count increment within 24 hours after platelet transfusion in haematological patients: A prospective observational study. Eur J Haematol 2017; 99:559-568. [DOI: 10.1111/ejh.12974] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/23/2017] [Indexed: 11/27/2022]
Affiliation(s)
- Sigurdur Benediktsson
- Department of Clinical Sciences; Lund University; Lund Sweden
- Department of Intensive and Perioperative Care; Skåne University Hospital in Lund; Lund Sweden
| | - Vladimir Lazarevic
- Department of Clinical Sciences; Lund University; Lund Sweden
- Department of Haematology, Oncology and Radiation Physics; Skåne University Hospital; Lund Sweden
| | - Lars Nilsson
- Department of Clinical Sciences; Lund University; Lund Sweden
- Department of Haematology, Oncology and Radiation Physics; Skåne University Hospital; Lund Sweden
| | - Jens Kjeldsen-Kragh
- Department of Clinical Sciences; Lund University; Lund Sweden
- Department of Clinical Immunology and Transfusion Medicine; Skåne University Hospital in Lund; Lund Sweden
| | - Ulf Schött
- Department of Clinical Sciences; Lund University; Lund Sweden
- Department of Intensive and Perioperative Care; Skåne University Hospital in Lund; Lund Sweden
| | - Thomas Kander
- Department of Clinical Sciences; Lund University; Lund Sweden
- Department of Intensive and Perioperative Care; Skåne University Hospital in Lund; Lund Sweden
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Doescher A, Petershofen EK, Hertenstein B, Kraemer D, Casper J, Schmidt JP, Müller TH. Platelet recovery and survival measured in patients by quantitative polymerase chain reaction of mitochondrial DNA. Transfusion 2014; 55:55-63. [PMID: 25056505 DOI: 10.1111/trf.12778] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2014] [Revised: 05/27/2014] [Accepted: 05/31/2014] [Indexed: 12/15/2022]
Abstract
BACKGROUND Mitochondrial (mt) DNA markers have been identified as potential targets for the quantification of endogenous and allogeneic platelets (PLTs) in the blood of individuals who received transfusions. Our goal was to develop a routine polymerase chain reaction (PCR) assay for ex vivo monitoring of PLT survival in patients after transfusion. STUDY DESIGN AND METHODS Targets were selected for real-time (RT)-PCR of mt DNA based on the frequency distribution of nucleotide polymorphisms and assay sensitivity in vitro. The assays were then evaluated with ex vivo samples to measure PLT survival and recovery of therapeutic doses of apheresis PLTs in hematooncologic patients with thrombocytopenia. RESULTS Nucleotides in two positions (73/310 hypervariable region [HVR] 2) and three positions (295 HVR 2, 16069/16311 HVR 1) had allele frequencies of approximately 0.5 and 0.85, respectively, in a population of 960 Caucasian PLT donors. They provided targets for sensitive assays detecting at least 1 × 10(3) PLTs per whole blood sample with adequate reproducibility (interassay coefficient of variation <4.0%). Transfusions of single-donor PLT concentrates in patients with thrombocytopenia (n = 30) were monitored with these markers. The mean 24-hour corrected count increment was 8.3 and the mean calculated survival time was 3.3 days. Results for a second marker were available for 13 transfusions. The survival time values derived from both markers for the same transfusion were almost identical (linear regression: r(2) = 0.957, slope = 0.87). CONCLUSION This RT-PCR method detects mt DNA polymorphisms in Caucasians for a highly sensitive and reproducible quantification of endogenous and allogeneic PLT numbers in blood samples from transfused patients with thrombocytopenia.
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Affiliation(s)
- Andrea Doescher
- DRK-Blutspendedienst NSTOB, Institut Bremen-Oldenburg, Oldenburg, Germany
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Perales Villarroel JP, Figueredo R, Guan Y, Tomaiuolo M, Karamercan MA, Welsh J, Selak MA, Becker LB, Sims C. Increased platelet storage time is associated with mitochondrial dysfunction and impaired platelet function. J Surg Res 2013; 184:422-9. [PMID: 23830370 DOI: 10.1016/j.jss.2013.05.097] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2013] [Revised: 05/13/2013] [Accepted: 05/16/2013] [Indexed: 01/24/2023]
Abstract
BACKGROUND Hemorrhagic shock is a leading cause of death following severe trauma, and platelet transfusions are frequently necessary to achieve hemostasis. Platelets, however, require special storage conditions, and storage time has been associated with loss of platelet quality. We hypothesized that standard storage conditions have a deleterious effect on platelet mitochondrial function and platelet activation. MATERIALS AND METHODS Platelet donations were collected from healthy donors (n = 5) and stored in gas-permeable collection bags according to American Association of Blood Bank recommendations. Platelet units were sampled from day of collection (day 0) until day 7. High-resolution respirometry was used to assess baseline mitochondrial respiration, maximal oxygen utilization, and individual mitochondrial complex-dependent respiration. Fluorescence-activated cell sorting was performed to analyze mitochondrial content, mitochondrial reactive oxygen species, the expression of P-selectin (both before and after challenge with thrombin receptor-activating peptide), and apoptosis. Data were analyzed using analysis of variance and Pearson correlation (P < 0.05 significant). RESULTS Mitochondrial respiration decreased significantly in platelets stored longer than 2 d (P < 0.05). Platelets also demonstrated a persistent decrease in response to stimulation with thrombin receptor-activating peptide by the third day of storage (P < 0.05) as well as an increase in mitochondrial reactive oxygen species and apoptosis (P < 0.05). Mitochondrial respiration significantly correlated with platelet capacity to activate (r = 0.8, P < 0.05). CONCLUSIONS Platelet mitochondrial respiratory function and activation response decrease significantly in platelets stored for 3 d or more. Because platelet transfusions almost universally occur between the third and fifth day of storage, our findings may have significant clinical importance and warrant further in vivo analysis.
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Affiliation(s)
- José Paul Perales Villarroel
- Division of Traumatology, Department of Surgery, Critical Care and Acute Care Surgery, University of Pennsylvania, Philadelphia, Pennsylvania 19104, USA
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