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Sokou R, Parastatidou S, Konstantinidi A, Tsantes AG, Iacovidou N, Piovani D, Bonovas S, Tsantes AE. Contemporary tools for evaluation of hemostasis in neonates. Where are we and where are we headed? Blood Rev 2024; 64:101157. [PMID: 38016836 DOI: 10.1016/j.blre.2023.101157] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2023] [Revised: 11/20/2023] [Accepted: 11/21/2023] [Indexed: 11/30/2023]
Abstract
The assessment of hemostatic disorders in neonates is crucial, but remains challenging for clinicians. Although the concept of developmental hemostasis is widely accepted among hemostasis specialists globally, it is probably under-recognized by clinicians and laboratory practitioners. In parallel with age-dependent hemostatic status maturation, comprehension of the differences between normal values is crucial for the accurate diagnosis of potential hemorrhagic and thrombotic disorders of the vulnerable neonatal population. This review outlines the basics of developmental hemostasis and the features of the available coagulation testing methods, with a focus on novel tools for evaluating the neonatal hemostatic profile. Common errors, issues, and pitfalls during the assessment of neonatal hemostasis are discussed, along with their impact on patient management. Current knowledge gaps and research areas are addressed. Further studying to improve our understanding of developmental hemostasis and its reflection on everyday clinical practice is warranted.
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Affiliation(s)
- Rozeta Sokou
- Neonatal Intensive Care Unit, "Agios Panteleimon" General Hospital of Nikea, Piraeus, Greece.
| | | | | | - Andreas G Tsantes
- Laboratory of Haematology and Blood Bank Unit, "Attiko" Hospital, School of Medicine, National and Kapodistrian University of Athens, Greece
| | - Nicoletta Iacovidou
- Neonatal Department, National and Kapodistrian University of Athens, Aretaieio Hospital, Athens, Greece
| | - Daniele Piovani
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; IRCCS Humanitas Research Hospital, Milan, Italy
| | - Stefanos Bonovas
- Department of Biomedical Sciences, Humanitas University, Milan, Italy; IRCCS Humanitas Research Hospital, Milan, Italy
| | - Argirios E Tsantes
- Laboratory of Haematology and Blood Bank Unit, "Attiko" Hospital, School of Medicine, National and Kapodistrian University of Athens, Greece
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Gestational Diabetes Melitus and Cord Blood Platelet Function Studied via the PFA-100 System. Diagnostics (Basel) 2022; 12:diagnostics12071645. [PMID: 35885550 PMCID: PMC9318840 DOI: 10.3390/diagnostics12071645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2022] [Revised: 07/02/2022] [Accepted: 07/04/2022] [Indexed: 11/18/2022] Open
Abstract
Neonatal platelet hemostasis, although it has been well described over the recent years, remains elusive in specific patient populations, including neonates from high-risk pregnancies, such as those complicated with gestational diabetes mellitus (GDM). We aimed at evaluating the platelet function of neonates born to mothers with GDM using the platelet function analyzer (PFA-100). Cord blood samples were drawn from each subject and tested with two different agonists to provide two closure time (CT) values (collagen with epinephrine (COL/EPI) and collagen with adenosine diphosphate (COL/ADP)). A total of 84 and 118 neonates formed the GDM and the control group (neonates from uncomplicated pregnancies), respectively. COL/EPI CTs were prolonged in neonates from the GDM group compared to neonates from the control group, while no statistically significant difference of COL/ADP CTs was noted between the two groups, GDM and the control. Higher COL/ADP CTs were demonstrated in neonates born via cesarean section and in neonates with blood group O. A negative correlation between COL/ADP CT and gestational age, white blood cells (WBCs) and von Willebrand factor (VWF) activity was noted in neonates from the GDM group. In conclusion, neonates from the GDM group demonstrate a more hyporesponsive phenotype of their platelets, in comparison to the control neonates.
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Favaloro EJ, Mohammed S, Vong R, Chapman K, Kershaw G, Just S, Connelly L, Ryan M, Zebeljan D, Brighton T, Pasalic L. Harmonizing platelet function analyzer testing and reporting in a large laboratory network. Int J Lab Hematol 2022; 44:934-944. [PMID: 35754202 PMCID: PMC9545980 DOI: 10.1111/ijlh.13907] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 05/30/2022] [Indexed: 11/29/2022]
Abstract
INTRODUCTION The platelet function analyzer (PFA) is a popular platelet function screening instrument, highly sensitive to von Willebrand disease (VWD) and to aspirin therapy, with moderate sensitivity to defects in platelet function and/or deficiencies in platelet number. There are two models, the original PFA-100 and the contemporary PFA-200. Normal reference ranges (NRRs) provided by the manufacturer are the same for both models, instead being based on the type of test cartridge, for which there are two main ones: collagen/epinephrine (C/Epi) and collagen/adenosine diphosphate (C/ADP). METHODS Comparative evaluations of PFA testing and reporting in six different sites of a large pathology network, aiming to harmonize NRRs and test reporting across all network sites. A separate comparative study of testing a range of samples (n > 150) on a PFA-100 versus that on a PFA-200. Review of contemporary literature. RESULTS Each site was identified to have a different reporting NRR, which after consolidating data permitted establishment of an agreed harmonized NRR for use across the network (C/Epi: 90-160; C/ADP: 70-124; based on n > 180). Similarly, each site reported and interpreted results in different ways, and after discussion and consolidation, a harmonized approach to interpretation and reporting was achieved. The separate comparative study of PFA-100 versus PFA-200 testing confirmed instrument equivalence. CONCLUSION We achieved harmonized NRRs and reporting for PFA testing across a large pathology network. Our approach may be useful for other laboratory networks wishing to harmonize PFA testing.
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Affiliation(s)
- Emmanuel J Favaloro
- Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), NSW Health Pathology, Westmead Hospital, Westmead, New South Wales, Australia.,Sydney Centres for Thrombosis and Haemostasis, Westmead, New South Wales, Australia.,Faculty of Science and Health, Charles Sturt University, Wagga Wagga, New South Wales, Australia
| | - Soma Mohammed
- Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), NSW Health Pathology, Westmead Hospital, Westmead, New South Wales, Australia
| | - Ronny Vong
- Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), NSW Health Pathology, Westmead Hospital, Westmead, New South Wales, Australia
| | - Kent Chapman
- Haematology, NSW Health Pathology, John Hunter Hospital, Newcastle, New South Wales, Australia
| | - Geoffrey Kershaw
- Haematology, NSW Health Pathology, Prince Alfred Hospital, Camperdown, New South Wales, Australia
| | - Sarah Just
- Haematology, NSW Health Pathology, Royal North Shore Hospital, St Leonards, New South Wales, Australia
| | - Lynne Connelly
- Haematology, NSW Health Pathology, Royal North Shore Hospital, St Leonards, New South Wales, Australia
| | - Michael Ryan
- Haematology, NSW Health Pathology, Wollongong Hospital, Wollongong, New South Wales, Australia
| | - Diane Zebeljan
- Haematology, NSW Health Pathology, Liverpool Hospital, Liverpool, New South Wales, Australia
| | - Timothy Brighton
- Haematology, NSW Health Pathology, Prince of Wales Hospital, Randwick, New South Wales, Australia
| | - Leonardo Pasalic
- Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), NSW Health Pathology, Westmead Hospital, Westmead, New South Wales, Australia.,Sydney Centres for Thrombosis and Haemostasis, Westmead, New South Wales, Australia.,Westmead Clinical School, University of Sydney, Westmead, New South Wales, Australia
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Abstract
The neonatal hemostatic system is different from that of adults. The differences in levels of procoagulant and anticoagulant factors and the evolving equilibrium in secondary hemostasis during the transition from fetal/neonatal life to infancy, childhood, and adult life are known as "developmental hemostasis." In regard to primary hemostasis, while the number (150,000-450,000/µl) and structure of platelets in healthy neonates closely resemble those of adults, there are significant functional differences between neonatal and adult platelets. Specifically, platelets derived from both cord blood and neonatal peripheral blood are less reactive than adult platelets to agonists, such as adenosine diphosphate (ADP), epinephrine, collagen, thrombin, and thromboxane (TXA2) analogs. This platelet hyporeactivity is due to differences in expression levels of key surface receptors and/or in signaling pathways, and is more pronounced in preterm neonates. Despite these differences in platelet function, bleeding times and PFA-100 closure times (an in vitro test of whole-blood primary hemostasis) are shorter in healthy full-term infants than in adults, reflecting enhanced primary hemostasis. This paradoxical finding is explained by the presence of factors in neonatal blood that increase the platelet-vessel wall interaction, such as high von Willebrand factor (vWF) levels, predominance of ultralong vWF multimers, high hematocrit, and high red cell mean corpuscular volume. Thus, the hyporeactivity of neonatal platelets should not be viewed as a developmental deficiency, but rather as an integral part of a developmentally unique, but well balanced, primary hemostatic system. In clinical practice, due to the high incidence of bleeding (especially intraventricular hemorrhage, IVH) among preterm infants, neonatologists frequently transfuse platelets to non-bleeding neonates when platelet counts fall below an arbitrary limit, typically higher than that used in older children and adults. However, recent studies have shown that prophylactic platelet transfusions not only fail to decrease bleeding in preterm neonates, but are associated with increased neonatal morbidity and mortality. In this review, we will describe the developmental differences in platelet function and primary hemostasis between neonates and adults, and will analyze the implications of these differences to platelet transfusion decisions.
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Affiliation(s)
- Francisca Ferrer-Marín
- Hematology and Medical Oncology Department. Hospital UniversitarioMorales-Meseguer. Centro Regional de Hemodonación. IMIB-Arrixaca. Murcia, Spain,CIBERER CB15/00055, Murcia, Spain,Grado de Medicina. Universidad Católica San Antonio (UCAM)
| | - Martha Sola-Visner
- Division of Newborn Medicine, Boston Children’s Hospital, Boston, MA,Harvard Medical School, Boston, MA
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Comparison Between Bleeding Time and PFA-200 to Evaluate Platelet Function Disorder in Children. J Pediatr Hematol Oncol 2021; 43:e748-e749. [PMID: 34157013 DOI: 10.1097/mph.0000000000001925] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Valsami S, Kollia M, Mougiou V, Sokou R, Isaakidou E, Boutsikou M, Pouliakis A, Iliodromiti Z, Carr R, Boutsikou T, Iacovidou N, Politou M. Evaluation of PFA-100 closure times in cord blood samples of healthy term and preterm neonates. Clin Chem Lab Med 2021; 58:e113-e116. [PMID: 31821165 DOI: 10.1515/cclm-2019-0948] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2019] [Accepted: 11/06/2019] [Indexed: 11/15/2022]
Affiliation(s)
- Serena Valsami
- Haematology Laboratory-Blood Bank, Aretaieio Hospital, National and Kapodistrian University of Athens, Athens, Greece
| | - Maria Kollia
- Neonatal Department, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Vasiliki Mougiou
- Neonatal Department, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Rozeta Sokou
- Neonatal Department, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Elina Isaakidou
- 2nd Local Health Unit of Keratsini-Drapetsona, 2nd Health Region of Pireus, Pireus, Greece
| | - Maria Boutsikou
- Neonatal Department, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Abraham Pouliakis
- 2nd Department of Pathology, National and Kapodistrian University of Athens, "Attikon" University Hospital, Athens, Greece
| | - Zoe Iliodromiti
- Neonatal Department, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Robert Carr
- Department of Haematology, Guy's and St Thomas' Hospital, King's College London, London, UK
| | - Theodora Boutsikou
- Neonatal Department, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Nicoletta Iacovidou
- Neonatal Department, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Marianna Politou
- Hematology- Immunohematology, Head of Haematology Laboratory-Blood Bank, Aretaieio Hospital, National and Kapodistrian University of Athens, 76 Vas. Sofias Street, 11526 Athens, Greece
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7
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Melero‐Amor A, Romecín P, Iyú D, García‐Bernal D, García‐Navaro E, Moraleda JM, García‐Estañ J, García‐Candel F, Atucha NM. Platelet function and microvesicle generation in patients with hemophilia A. Clin Case Rep 2021; 9:1408-1415. [PMID: 33768856 PMCID: PMC7981769 DOI: 10.1002/ccr3.3788] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2020] [Accepted: 10/30/2020] [Indexed: 11/13/2022] Open
Abstract
Our results do not support any effect of FVIII on platelet function in patients with severe HA treated under the regime of prophylaxis.
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Affiliation(s)
- Antonia Melero‐Amor
- Servicio de HematologíaHospital Universitario Virgen de la ArrixacaMurciaSpain
| | - Paola Romecín
- Departamento de FisiologíaFacultad de MedicinaUniversidad de MurciaMurciaSpain
- Instituto Murciano de Investigación BiosanitariaUnidad de Trasplante Hematopoyético y Terapia CelularMurciaSpain
| | - David Iyú
- Departamento de FisiologíaFacultad de MedicinaUniversidad de MurciaMurciaSpain
- Instituto Murciano de Investigación BiosanitariaUnidad de Trasplante Hematopoyético y Terapia CelularMurciaSpain
| | - David García‐Bernal
- Instituto Murciano de Investigación BiosanitariaUnidad de Trasplante Hematopoyético y Terapia CelularMurciaSpain
| | - Esther García‐Navaro
- Departamento de FisiologíaFacultad de MedicinaUniversidad de MurciaMurciaSpain
- Instituto Murciano de Investigación BiosanitariaUnidad de Trasplante Hematopoyético y Terapia CelularMurciaSpain
| | - José M. Moraleda
- Servicio de HematologíaHospital Universitario Virgen de la ArrixacaMurciaSpain
- Instituto Murciano de Investigación BiosanitariaUnidad de Trasplante Hematopoyético y Terapia CelularMurciaSpain
- Departamento de Medicina InternaFacultad de MedicinaUniversidad de MurciaMurciaSpain
| | - Joaquín García‐Estañ
- Departamento de FisiologíaFacultad de MedicinaUniversidad de MurciaMurciaSpain
- Instituto Murciano de Investigación BiosanitariaUnidad de Trasplante Hematopoyético y Terapia CelularMurciaSpain
| | - Faustino García‐Candel
- Servicio de HematologíaHospital Universitario Virgen de la ArrixacaMurciaSpain
- Instituto Murciano de Investigación BiosanitariaUnidad de Trasplante Hematopoyético y Terapia CelularMurciaSpain
| | - Noemí M. Atucha
- Departamento de FisiologíaFacultad de MedicinaUniversidad de MurciaMurciaSpain
- Instituto Murciano de Investigación BiosanitariaUnidad de Trasplante Hematopoyético y Terapia CelularMurciaSpain
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Abstract
The neonatal hemostatic system is strikingly different from that of adults. Among other differences, neonates exhibit hyporeactive platelets and decreased levels of coagulation factors, the latter translating into prolonged clotting times (PT and PTT). Since pre-term neonates have a high incidence of bleeding, particularly intraventricular hemorrhages, neonatologists frequently administer blood products (i.e., platelets and FFP) to non-bleeding neonates with low platelet counts or prolonged clotting times in an attempt to overcome these "deficiencies" and reduce bleeding risk. However, it has become increasingly clear that both the platelet hyporeactivity as well as the decreased coagulation factor levels are effectively counteracted by other factors in neonatal blood that promote hemostasis (i.e., high levels of vWF, high hematocrit and MCV, reduced levels of natural anticoagulants), resulting in a well-balanced neonatal hemostatic system, perhaps slightly tilted toward a prothrombotic phenotype. While life-saving in the presence of active major bleeding, the administration of platelets and/or FFP to non-bleeding neonates based on laboratory tests has not only failed to decrease bleeding, but has been associated with increased neonatal morbidity and mortality in the case of platelets. In this review, we will present a clinical overview of bleeding in neonates (incidence, sites, risk factors), followed by a description of the key developmental differences between neonates and adults in primary and secondary hemostasis. Next, we will review the clinical tests available for the evaluation of bleeding neonates and their limitations in the context of the developmentally unique neonatal hemostatic system, and will discuss current and emerging approaches to more accurately predict, evaluate and treat bleeding in neonates.
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Affiliation(s)
- Patricia Davenport
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA, United States
| | - Martha Sola-Visner
- Division of Newborn Medicine, Boston Children's Hospital, Boston, MA, United States
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9
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Mondal S, Hollander KN, Ibekwe SO, Williams B, Tanaka K. Heyde Syndrome-Pathophysiology and Perioperative Implications. J Cardiothorac Vasc Anesth 2020; 35:3331-3339. [PMID: 33132021 DOI: 10.1053/j.jvca.2020.10.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2020] [Revised: 10/02/2020] [Accepted: 10/04/2020] [Indexed: 11/11/2022]
Abstract
Gastrointestinal (GI) bleeding in patients with calcific aortic valve stenosis (AVS), termed Heyde syndrome, was first described by Edward C. Heyde. The strong association between valvular replacement and the eradication of clinically significant GI bleeding confirmed an underlying pathophysiologic relationship. The rheologic stress created by AVS increases proteolysis of von Willebrand factor (VWF), resulting in loss of predominantly high-molecular-weight VWF (Hmw VWF). Angiodysplastic vessels present in patients with AVS, coupled with the lack of functioning Hmw VWF, increase the risk for GI bleeds. Aortic valve replacement, both surgical and transcatheter-based, is often a definitive treatment for GI bleeding, leading to recovery of Hmw VWF multimers. Perioperative management of patients involves monitoring their coagulation profiles with relevant laboratory tests and instituting appropriate management. Management can be directed in the following two ways: by improving internal release of VWF or by administration of external therapeutics containing VWF. It is important for perioperative physicians to obtain an understanding of the pathophysiology of this disease process and closely monitor the bleeding pattern so that targeted therapies can be initiated.
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Affiliation(s)
- Samhati Mondal
- Department of Anesthesiology, Cardiac Anesthesia Division, University of Maryland School of Medicine, Baltimore, MD.
| | - Kimberly N Hollander
- Department of Anesthesiology, Cardiac Anesthesia Division, University of Maryland School of Medicine, Baltimore, MD
| | - Stephanie O Ibekwe
- Department of Anesthesiology, Cardiovascular Division, BTGH, Baylor College of Medicine, Houston, TX
| | - Brittney Williams
- Department of Anesthesiology, Cardiac Anesthesia Division, University of Maryland School of Medicine, Baltimore, MD
| | - Kenichi Tanaka
- Department of Anesthesiology, Cardiac Anesthesia Division, University of Maryland School of Medicine, Baltimore, MD
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10
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Abstract
Although the hemostatic potential of adult platelets has been investigated extensively, regulation of platelet function during fetal life is less clear. Recent studies have provided increasing evidence for a developmental control of platelet function during fetal ontogeny. Fetal platelets feature distinct differences in reactive properties compared with adults. These differences very likely reflect a modified hemostatic and homeostatic environment in which platelet hyporeactivity contributes to prevent pathological clot formation on the one hand but still ensures sufficient hemostasis on the other hand. In this review, recent findings on the ontogeny of platelet function and reactivity are summarized, and implications for clinical practice are critically discussed. This includes current platelet-transfusion practice and its potential risk in premature infants and neonates.
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11
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Nair AB, Parker RI. Hemostatic Testing in Critically Ill Infants and Children. Front Pediatr 2020; 8:606643. [PMID: 33490001 PMCID: PMC7820389 DOI: 10.3389/fped.2020.606643] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 12/10/2020] [Indexed: 12/12/2022] Open
Abstract
Children with critical illness frequently manifest imbalances in hemostasis with risk of consequent bleeding or pathologic thrombosis. Traditionally, plasma-based tests measuring clot formation by time to fibrin clot generation have been the "gold standard" in hemostasis testing. However, these tests are not sensitive to abnormalities in fibrinolysis or in conditions of enhanced clot formation that may lead to thrombosis. Additionally, they do not measure the critical roles played by platelets and endothelial cells. An added factor in the evaluation of these plasma-based tests is that in infants and young children plasma levels of many procoagulant and anticoagulant proteins are lower than in older children and adults resulting in prolonged clot generation times in spite of maintaining a normal hemostatic "balance." Consequently, newer assays directly measuring thrombin generation in plasma and others assessing the stages hemostasis including clot initiation, propagation, and fibrinolysis in whole blood by viscoelastic methods are now available and may allow for a global measurement of the hemostatic system. In this manuscript, we will review the processes by which clots are formed and by which hemostasis is regulated, and the rationale and limitations for the more commonly utilized tests. We will also discuss selected newer tests available for the assessment of hemostasis, their "pros" and "cons," and how they compare to the traditional tests of coagulation in the assessment and management of critically ill children.
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Affiliation(s)
- Alison B Nair
- Pediatric Critical Care Medicine, University of California, San Francisco, San Francisco, CA, United States
| | - Robert I Parker
- Pediatric Hematology/Oncology, Renaissance School of Medicine, Stony Brook University, Stony Brook, NY, United States
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12
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Pelland-Marcotte MC, Humpl T, James PD, Rand ML, Bouskill V, Reyes JT, Bowman ML, Carcao MD. Idiopathic pulmonary arterial hypertension - a unrecognized cause of high-shear high-flow haemostatic defects (otherwise referred to as acquired von Willebrand syndrome) in children. Br J Haematol 2018; 183:267-275. [PMID: 30141279 DOI: 10.1111/bjh.15530] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2018] [Accepted: 06/21/2018] [Indexed: 02/06/2023]
Abstract
Acquired von Willebrand syndrome (AVWS) is reported in high-flow high-shear congenital cardiac disorders. We hypothesized that the narrowed pulmonary vasculature in idiopathic pulmonary arterial hypertension (IPAH) may induce AVWS. We conducted a cross-sectional evaluation of children with IPAH. Patients with bleeding symptoms and/or laboratory abnormalities (thrombocytopenia, anomalies in coagulation screening tests) were tested in-depth for haemostatic defects. Fourteen children were followed with IPAH of which 8 were eligible. Four children exhibited abnormal bleeding scores (International Society on Thrombosis and Haemostasis Bleeding Assessment Tool: 3-5). All 8 patients showed very prolonged platelet function analyser (PFA)-100 closure times. Six children demonstrated either mild thrombocytopenia or low-normal von Willebrand factor (VWF) antigen (VWF:Ag) or VWF activity [mean (range), in iu/dl: VWF:Ag: 70 (61-91); VWF activity: 57 (34-70)]. Average VWF collagen binding capacity (VWF:CB) was 64 iu/dl (range: 53-123 iu/dl), with low-normal VWF activity/VWF:Ag or VWF:CB/VWF:Ag ratios occurring in five patients. All children had normal multimers distribution patterns. One patient underwent a lung transplantation, with normalization of haemostatic abnormalities post-surgery. Overall, 8 out of 14 children with IPAH had mild to moderate bleeding symptoms and/or laboratory abnormalities in keeping with AVWS. Normalization of the haemostatic defects following lung transplantation and lack of family history of bleeding attests to the acquired nature of their defects.
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Affiliation(s)
- Marie-Claude Pelland-Marcotte
- Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto, Toronto, ON, Canada
| | - Tilman Humpl
- Division of Cardiology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto, Toronto, ON, Canada
| | - Paula D James
- Department of Medicine, Queen's University, Kingston, ON, Canada
| | - Margaret L Rand
- Division of Haematology/Oncology, Translational Medicine, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada.,Departments of Laboratory Medicine & Pathobiology, Biochemistry and Paediatrics, University of Toronto, Toronto, ON, Canada
| | - Vanessa Bouskill
- Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto, Toronto, ON, Canada.,Department of Nursing, The Hospital for Sick Children, Toronto, ON, Canada
| | - Janette T Reyes
- Division of Cardiology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto, Toronto, ON, Canada.,Department of Nursing, The Hospital for Sick Children, Toronto, ON, Canada
| | - Mackenzie L Bowman
- Department of Medicine, Queen's University, Kingston, ON, Canada.,Department of Pathology and Molecular Medicine, Queen's University, Kingston, ON, Canada
| | - Manuel D Carcao
- Division of Haematology/Oncology, Department of Paediatrics, The Hospital for Sick Children and University of Toronto, Toronto, ON, Canada.,Child Health Evaluative Sciences, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
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13
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Kahvecioglu D, Erdeve O, Akduman H, Ucar T, Alan S, Çakır U, Yıldız D, Atasay B, Arsan S, Atalay S. Influence of platelet count, platelet mass index, and platelet function on the spontaneous closure of ductus arteriosus in the prematurity. Pediatr Neonatol 2018; 59:53-57. [PMID: 28739214 DOI: 10.1016/j.pedneo.2017.01.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 12/27/2016] [Accepted: 01/23/2017] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND This study aims at evaluating the influence of platelet count, platelet mass index, and platelet function on the spontaneous closure of ductus arteriosus in prematurity. METHODS All preterm babies were divided into two groups, including Group 1 with "open PDA" and Group 2 with "closed PDA". The variables of platelet count, mean platelet volume, platelet mass index, and platelet function were analyzed and compared between two groups of patients to identify the factors that significantly influenced spontaneous closure of ductus arteriosus. RESULTS Twenty-four patients were in the "open PDA" group, whereas 36 patients were in the "closed PDA" group. Mean GA and BW were 27.6 ± 1.8 (23.1-30.4) and 28 ± 1.6 (23.4-30.6) weeks and 1009 ± 270 (585-1480) g and 1035 ± 298 (505-1500) g in "open PDA" and "closed PDA" groups, respectively (p > 0.05). The incidence of "Collagen-ADP > 130 s" was significantly higher in the "open PDA" group, and the levels of hemoglobin and hematocrit were significantly lower in the "open PDA" group (p < 0.05). Multivariate logistic regression analysis showed that respiratory distress syndrome (OR: 9, CI: 1.5-51.8) and collagen-ADP > 130 s (OR: 5.7 CI: 1.55-21.3) are two independent factors associated with ductal patency. CONCLUSION This is the first study in the English literature providing evidence of the influence of platelet dysfunction on the spontaneous closure of ductus arteriosus in prematurity. Longer collagen-ADP duration is identified as a risk factor of ductal closure.
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Affiliation(s)
- Dilek Kahvecioglu
- Ankara University, School of Medicine, Department of Pediatrics, Division of Neonatology, Ankara, Turkey.
| | - Omer Erdeve
- Ankara University, School of Medicine, Department of Pediatrics, Division of Neonatology, Ankara, Turkey
| | - Hasan Akduman
- Ankara University, School of Medicine, Department of Pediatrics, Division of Neonatology, Ankara, Turkey
| | - Tayfun Ucar
- Ankara University, School of Medicine, Department of Pediatrics, Division of Pediatric Cardiology, Ankara, Turkey
| | - Serdar Alan
- Ankara University, School of Medicine, Department of Pediatrics, Division of Neonatology, Ankara, Turkey
| | - Ufuk Çakır
- Ankara University, School of Medicine, Department of Pediatrics, Division of Neonatology, Ankara, Turkey
| | - Duran Yıldız
- Ankara University, School of Medicine, Department of Pediatrics, Division of Neonatology, Ankara, Turkey
| | - Begum Atasay
- Ankara University, School of Medicine, Department of Pediatrics, Division of Neonatology, Ankara, Turkey
| | - Saadet Arsan
- Ankara University, School of Medicine, Department of Pediatrics, Division of Neonatology, Ankara, Turkey
| | - Semra Atalay
- Ankara University, School of Medicine, Department of Pediatrics, Division of Pediatric Cardiology, Ankara, Turkey
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14
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Revel-Vilk S. Neonatal haemostasis. Hamostaseologie 2017; 36:261-264. [DOI: 10.5482/hamo-15-11-0032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2015] [Accepted: 01/14/2016] [Indexed: 11/05/2022] Open
Abstract
SummaryThe maturation and postnatal development of the human coagulation system results in significant and important differences in the coagulation and fibrinolysis of neonates and young children compared to older children and adults. Importantly, these differences, which mostly reflect the immaturity of the neonatal haemostasis system, are functionally balanced. Healthy neonates show no signs of easy bruising or other bleeding diathesis and no increased tendency to thrombosis for any given stimulus compared to adults.Systemic diseases may affect haemostasis, thus predisposing ill neonates to increased risk for haemorrhagic or thrombotic complications. In hospitalized children, neonates have increased risk of developing thrombosis compared to infants and children, mostly associated with the presence of central venous catheter. For diagnosis of haemostasis disorders, diagnostic laboratories processing pediatric samples should use age, analyzer and reagent appropriate reference ranges. Age specific guidelines should be followed for the management of neonates with hemostatic disorders.
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15
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Riedl J, Ay C, Pabinger I. Platelets and hemophilia: A review of the literature. Thromb Res 2017; 155:131-139. [DOI: 10.1016/j.thromres.2017.05.013] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2016] [Revised: 05/10/2017] [Accepted: 05/11/2017] [Indexed: 10/19/2022]
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16
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Yaoi H, Shida Y, Ogiwara K, Hosokawa K, Shima M, Nogami K. Role of red blood cells in the anemia-associated bleeding under high shear conditions. Haemophilia 2017; 23:750-758. [PMID: 28470853 DOI: 10.1111/hae.13252] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/16/2017] [Indexed: 11/28/2022]
Abstract
BACKGROUND Red blood cells (RBCs) contribute to hemostasis under blood-flow, and anemia might contribute to a hemorrhagic diathesis. The majority of current laboratory techniques to assess hemostasis do not consider the effects of RBCs. An assay to determine the role of RBCs in hemostasis could be beneficial for clinical management. OBJECTIVES To investigate the influence of RBCs in hemostasis. METHODS Hemostasis was investigated using a novel microchip flow-chamber system (T-TAS® ) in an anemic patient with von Willebrand disease. Subsequently, the effects of RBCs in total thrombus analysis system (T-TAS) were examined using reconstituted whole blood at various hematocrit levels. RESULTS In vivo: When the patient was anemic and demonstrated persisted hemorrhagic symptoms despite the maintained adequate von Willebrand factor ristocetin cofactor activity levels, thrombus formation determined by T-TAS was delayed. However, transfusions of RBCs resolved bleeding symptom and, accordingly, the thrombus formation in T-TAS improved. In vitro: Thrombus formation determined by T-TAS at 1000 s-1 was dose-dependent on hematocrit (the time to reach 10 kPa (T10 ): 10.0 ± 0, 9.5 ± 1.4, 6.7 ± 2.4, 2.8 ± 1.6 min at hematocrits of 0%, 12.5%, 25% and 50%, respectively). Markedly defective thrombus formation (T10 >10 min) was confirmed at a hematocrit <25% at 2000 s-1 . CONCLUSION Red blood cells play an essential role in hemostasis under high shear, and RBC transfusions could be effective for refractory bleeding in patients with anemia. T-TAS measurements appear to reflect the hemostatic consequences of diminished red cell numbers under blood-flow, and could provide a valuable means for monitoring patients.
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Affiliation(s)
- H Yaoi
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - Y Shida
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - K Ogiwara
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - K Hosokawa
- Research Institute, Fujimori Kogyo Co., Ltd., Yokohama, Kanagawa, Japan
| | - M Shima
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan
| | - K Nogami
- Department of Pediatrics, Nara Medical University, Kashihara, Nara, Japan
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17
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Al-Battat S, Rand ML, Bouskill V, Lau W, Blanchette VS, Kahr WHA, Rivard GE, Carcao MD. Glanzmann thrombasthenia platelets compete with transfused platelets, reducing the haemostatic impact of platelet transfusions. Br J Haematol 2017; 181:410-413. [PMID: 28466602 DOI: 10.1111/bjh.14623] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Sami Al-Battat
- Division of Haematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.,Department of Paediatrics, University of Toronto, Toronto, ON, Canada
| | - Margaret L Rand
- Division of Haematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.,Department of Paediatrics, University of Toronto, Toronto, ON, Canada.,Departments of Laboratory Medicine & Pathobiology, Biochemistry and Paediatrics, University of Toronto, Toronto, ON, Canada.,Physiology and Experimental Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Vanessa Bouskill
- Department of Nursing, The Hospital for Sick Children, Toronto, ON, Canada
| | - Wendy Lau
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON, Canada
| | - Victor S Blanchette
- Division of Haematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.,Department of Paediatrics, University of Toronto, Toronto, ON, Canada
| | - Walter H A Kahr
- Division of Haematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.,Department of Paediatrics, University of Toronto, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada.,Cell Biology Program, Research Institute, The Hospital for Sick Children, Toronto, ON, Canada
| | - Georges-Etienne Rivard
- Division of Haematology/Oncology, Department of Paediatrics, CHU Sainte-Justine, Montreal, QC, Canada
| | - Manuel D Carcao
- Division of Haematology/Oncology, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada.,Department of Paediatrics, University of Toronto, Toronto, ON, Canada.,Child Health Evaluative Sciences, The Hospital for Sick Children, University of Toronto, Toronto, ON, Canada
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18
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Abstract
INTRODUCTION Platelets play a key role in primary hemostasis and are also intricately linked to secondary hemostasis. Investigation of platelet function in children, especially in neonates, is seriously challenged by the volumes required to perform the majority of platelet function tests and due to the lack of standardization of these tests for use in children. Areas covered: The present review summarizes developmental hemostasis with a focus on the differences in platelet adhesion, activation and aggregation, between preterm neonates, full-term neonates, during childhood and in adults. Some of the most widely used platelet function tests are presented, including novel tests requiring only a small blood volume. Expert commentary: Currently available platelet function tests are limited as regards to investigation of neonates due to difficulties in obtaining adequate blood volume, poor standardization, lack of reference intervals for neonates and children, and an incomplete understanding of the functional phenotype of neonatal platelets, especially preterm neonatal platelets.
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Affiliation(s)
- Anne-Mette Hvas
- a Centre for Haemophilia and Thrombosis, Department of Clinical Biochemistry , Aarhus University Hospital , Aarhus , Denmark
| | - Emmanuel J Favaloro
- b Department of Haematology , Sydney Centres for Thrombosis and Haemostasis, Institute of Clinical Pathology and Medical Research (ICPMR), Westmead Hospital , Westmead , Australia
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19
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Monitoring aspirin therapy in children after interventional cardiac catheterization: laboratory measures, dose response, and clinical outcomes. Eur J Pediatr 2015; 174:933-41. [PMID: 25589198 DOI: 10.1007/s00431-014-2485-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/04/2014] [Revised: 12/14/2014] [Accepted: 12/19/2014] [Indexed: 10/24/2022]
Abstract
UNLABELLED Very few studies have investigated dose response of aspirin and agreement of different platelet function assays in children. One hundred five children were studied at baseline and after interventional cardiac catheterization during aspirin treatment and, in cases of aspirin resistance (AR), after dose increase. Results from arachidonate-induced aggregation (AA) were compared with aggregation induced by ADP, PFA-100 closure times (CTs), urinary 11-dehydro-thromboxane B2 (urinary 11-dhTxB2) levels, and Impact-R % surface coverage. Aspirin at 2-5 mg/kg/day inhibited platelet function in a large majority. While 19 % showed bruising and mild epistaxis, no thrombotic complications were recorded. AR was detected by AA in seven children (6.7 %). After dose increase, the majority showed inhibition by aspirin. Infants had higher urinary 11-dhTxB2 baseline levels; this assay showed some correlation with AA. Both assays manifested high sensitivity and specificity for aspirin while inferior results were found for the other assays. With the PFA-100, 15.2 % of patients were found to have AR, but this corresponded to AR by AA in only one of seven children. CONCLUSION While there was poor agreement among assays, AA and urinary 11-dhTxB2 show good specificity for the monitoring of aspirin therapy in children. Aspirin at 2-5 mg/kg inhibits platelet function; AR in children is rare and can be overcome by dose increase.
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20
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Dovlatova N. Current status and future prospects for platelet function testing in the diagnosis of inherited bleeding disorders. Br J Haematol 2015; 170:150-61. [PMID: 25920378 DOI: 10.1111/bjh.13405] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Platelets play a crucial role in haemostasis by preventing bleeding at the site of vascular injury. Several defects in platelet morphology and function have been identified and described over the years. Although a range of methodologies is available to assess platelet function, a significant proportion of subjects with bleeding symptoms and normal coagulation parameters still appear to have normal results on platelet function testing. This might suggest that the reason for bleeding is multifactorial and is due to a combination of several minor defects in platelet function and/or other parts of the haemostatic system or might indicate that the currently available platelet function tests do not provide optimal diagnostic power. This review will summarize the established platelet function tests used for diagnosing inherited platelet abnormalities in adults and children, and discuss the newly developed methodologies as well as unmet challenges and potential areas for further improvement in this field.
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Affiliation(s)
- Natalia Dovlatova
- Division of Clinical Neuroscience, Thrombosis and Haemostasis Research Group, Queens Medical Centre, University of Nottingham, Nottingham, UK
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21
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High flow velocity through congenital cardiac lesions predicts preoperative platelet dysfunction. Ann Thorac Surg 2015; 99:1379-85. [PMID: 25661905 DOI: 10.1016/j.athoracsur.2014.10.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Revised: 10/08/2014] [Accepted: 10/21/2014] [Indexed: 11/21/2022]
Abstract
BACKGROUND Platelet dysfunction resulting from abnormal fluid shear stress has been reported in adults with aortic stenosis. Blood flowing through a congenital heart defect at greater than normal velocity is subjected to increased shear stress. The primary aim was to determine whether peak flow velocity through congenital cardiac lesions predicts preoperative platelet dysfunction. METHODS The charts of 402 patients who underwent cardiopulmonary bypass and had preoperative platelet function analysis were evaluated. Platelet dysfunction was measured as a prolonged closure time (CT) in seconds with a platelet function analyzer. Echocardiography was used to determine peak velocity. The relationship between peak velocity and CT was analyzed using linear regression and Kaplan-Meier estimation. RESULTS The distribution of peak velocity was bimodal. The mean velocity of the lower group was 1.9 m/second and the higher group was 4.2 m/second. Univariate analysis showed age, weight, peak velocity, hematocrit, and Risk Adjustment for Congenital Heart Surgery score to be associated with prolonged CT. Using multivariable analysis, prolonged CT was significantly associated with peak velocity (p < 0.001). For each 1m/second increase in peak velocity the CT increased by over 9 seconds (p < 0.001). In addition, a median CT increase of more than 6 seconds was also associated with a 5 percentage point drop in hematocrit (p = 0.04). CONCLUSIONS Platelet dysfunction is associated with high blood flow velocity through congenital cardiac lesions. Lower preoperative hematocrit was associated with prolonged CT, which may suggest subclinical bleeding secondary to platelet dysfunction.
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22
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Andres O, Schulze H, Speer CP. Platelets in neonates: central mediators in haemostasis, antimicrobial defence and inflammation. Thromb Haemost 2014; 113:3-12. [PMID: 25185520 DOI: 10.1160/th14-05-0476] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2014] [Accepted: 07/07/2014] [Indexed: 12/26/2022]
Abstract
Platelets are not only centrally involved in haemostasis, but also in antimicrobial defence and inflammation. Since evaluation of platelet physiology in the particular patient group of preterm and term neonatal infants is highly restricted for ethical reasons, there are hardly any data available in healthy and much less in extremely immature or ill neonates. By summarising current knowledge and addressing both platelet researchers and neonatologists, we describe neonatal platelet count and morphology, report on previous analyses of neonatal platelet function in primary haemostasis and provide insights into recent advances in platelet immunology that considerably impacts our clinical view on the critically ill neonatal infant. We conclude that neonatal platelets, originating from liver megakaryocytes, substantially differ from adult platelets and may play a pivotal role in the pathophysiology of neonatal sepsis or intraventricular haemorrhage, both complications which seriously augment perinatal morbidity and mortality.
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Affiliation(s)
- Oliver Andres
- Dr. med. Oliver Andres, University Children's Hospital Würzburg, Josef-Schneider-Straße 2, 97080 Würzburg, Germany, Tel.: +49 931 201 27728, Fax: +49 931 201 6027799, E-mail:
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23
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Bailly DK, Boshkov LK, Zubair MM, Rogers VJC, Lantz G, Armsby L, Hohimer AR, Martchenke J, Sochacki P, Langley SM. Congenital cardiac lesions involving systolic flow abnormalities are associated with platelet dysfunction in children. Ann Thorac Surg 2014; 98:1419-24. [PMID: 25130078 DOI: 10.1016/j.athoracsur.2014.05.035] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Revised: 05/02/2014] [Accepted: 05/12/2014] [Indexed: 11/28/2022]
Abstract
BACKGROUND Shear stress-induced platelet dysfunction (PD) is prevalent among adults with aortic stenosis. Our aim was to determine whether abnormal platelet function was associated with specific congenital cardiac lesions in children. METHODS The charts of 407 children who had undergone cardiopulmonary bypass and had preoperative platelet function analysis were evaluated. Patients were assigned to 1 of 11 different lesion categories. Platelet dysfunction (PD) was defined as prolonged closure time (CT) as measured with a platelet function analyzer. Odds ratio (OR) estimates for prolonged CT were calculated for each lesion category. Mean CTs were compared with Tukey-Kramer separated means testing. Analysis of variance modeling was used to determine association between hematocrit value and CT. RESULTS CT in patients with ventricular septal defects (VSD) and right ventricular outflow tract obstruction (RVOTO) lesions was prolonged. OR analysis found that patients with VSDs (OR, 2.46) or RVOTO (OR, 2.88) had at least a 95% probability of an abnormal CT. In contrast, patients with atrial septal defect (ASD), bidirectional Glenn procedure (BDG), and pulmonary insufficiency (PI) had a reduced probability of a prolonged CT (p < 0.05). A similar pattern was seen in parametric analysis comparing mean CTs across lesion categories. A lower preoperative hematocrit value was associated with prolonged CTs across all lesion types (p < 0.05). CONCLUSIONS PD was common in children with congenital cardiac lesions involving systolic flow abnormalities and was uncommon among children with lesions having diastolic abnormalities. Lower preoperative hematocrit values were associated with prolonged CTs, suggesting subclinical bleeding secondary to excessive platelet shearing.
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Affiliation(s)
- David K Bailly
- Department of Pediatrics, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - Lynn K Boshkov
- Department of Pediatrics, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon; Department of Pathology, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - M Mujeeb Zubair
- Department of Surgery, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - Vanessa J C Rogers
- Department of Surgery, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - Gurion Lantz
- Department of Surgery, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - Laurie Armsby
- Department of Pediatrics, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - A Roger Hohimer
- Department of Obstetrics, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - Julie Martchenke
- Department of Pediatrics, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - Paul Sochacki
- Department of Pathology, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon
| | - Stephen M Langley
- Department of Pediatrics, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon; Department of Surgery, Doernbecher Children's Hospital, Oregon Health & Science University, Portland, Oregon.
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24
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Abstract
Platelet function testing has evolved from crude tests, such as the bleeding time, to tests that permit a relatively sophisticated evaluation of platelet activity. Nonetheless, these tests are hampered by lack of specificity and sensitivity, and poor standardization of methods and techniques. The bleeding time, which has long been a staple of hemostasis testing, has been dropped from the test menu at many laboratories. In its place, tests such as the Platelet Function Analyzer-100 are increasingly used to screen patients with possible bleeding disorders. Older tests, such as platelet aggregometry and lumiaggregometry, are still used frequently because they provide insight into receptor, signaling pathway and granule release mechanisms. Flow cytometry is available in some specialized laboratories and allows for quantitative and qualitative assessment of some platelet functions, although the expense of testing is often prohibitive. Finally, the wider availability of platelet function testing has stimulated interest and demand for monitoring the effect of platelet inhibitory drugs, such as aspirin and clopidogrel. As platelet function pathways become better understood, the demand for these type of monitoring tests is likely to increase.
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Affiliation(s)
- Amer M Zeidan
- Division of Hospital Medicine, Department of Medicine, Rochester General Hospital, Rochester, NY 14621, USA.
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25
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Kumar R, Carcao M. Inherited abnormalities of coagulation: hemophilia, von Willebrand disease, and beyond. Pediatr Clin North Am 2013; 60:1419-41. [PMID: 24237980 DOI: 10.1016/j.pcl.2013.09.002] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Bleeding disorders are broadly classified into primary and secondary hemostatic defects. Primary hemostatic disorders (disorders of platelets and von Willebrand factor) mainly result in mucocutaneous bleeding symptoms such as epistaxis, menorrhagia, petechiae, easy bruising, and bleeding after dental and surgical interventions. Secondary hemostatic disorders (congenital or acquired deficiencies of coagulation factors) typically manifest with delayed, deep bleeding into muscles and joints. This article provides a generalized overview of the pathophysiology, clinical manifestations, laboratory abnormalities, and molecular basis of inherited abnormalities of coagulation with a focus on hemophilia, von Willebrand disease, and rare inherited coagulation disorders.
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Affiliation(s)
- Riten Kumar
- Division of Haematology/Oncology, Department of Paediatrics, Hospital for Sick Children, University of Toronto, 555 University Avenue, Toronto, Ontario M5G 1X8, Canada
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26
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Song SH, Lim CS, Shin S. Migration distance-based platelet function analysis in a microfluidic system. BIOMICROFLUIDICS 2013; 7:64101. [PMID: 24396535 PMCID: PMC3838424 DOI: 10.1063/1.4829095] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 10/23/2013] [Indexed: 06/03/2023]
Abstract
Aggregation and adhesion of platelets to the vascular wall are shear-dependent processes that play critical roles in hemostasis and thrombosis at vascular injury sites. In this study, we designed a simple and rapid assay of platelet aggregation and adhesion in a microfluidic system. A shearing mechanism using a rotating stirrer provided adjustable shear rate and shearing time and induced platelet activation. When sheared blood was driven through the microchannel under vacuum pressure, shear-activated platelets adhered to a collagen-coated surface, causing blood flow to significantly slow and eventually stop. To measure platelet adhesion and aggregation, the migration distance (MD) of blood through the microchannel was monitored. As the microstirrer speed increased, MD initially decreased exponentially but then increased beyond a critical rpm. For platelet-excluded blood samples, there were no changes in MD with increasing stirrer speed. These findings imply that the stirrer provided sufficiently high shear to activate platelets and that blood MD is a potentially valuable index for measuring the shear-dependence of platelet activation. Our microfluidic system is quick and simple, while providing a precise assay to measure the effects of shear on platelet aggregation and adhesion.
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Affiliation(s)
- Suk-Heung Song
- School of Mechanical Engineering, Korea University, 136-713 Seoul, South Korea
| | - Chae-Seung Lim
- Department of Laboratory Medicine, Guro Hospital, College of Medicine, Korea University, Seoul, South Korea
| | - Sehyun Shin
- School of Mechanical Engineering, Korea University, 136-713 Seoul, South Korea
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27
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Abstract
The platelet-function analyzer, PFA-100, is a relatively novel method for rapid in vitro global evaluation of primary hemostasis. The aim of this review is to summarize the published studies reporting on the utility of the PFA-100 device as a screening tool for primary hemostasis. Data were identified by searches of the published literature, including PubMed, references from reviews and abstracts from the most important meetings on this topic. The literature data support the use of the PFA-100 as a useful screening tool for the investigation of von Willebrand's disease and other acquired and congenital intrinsic platelet function disorders. Moreover, it is useful for evaluating primary hemostasis before surgical procedures and for monitoring desmopressin therapy in both von Willebrand's disease and platelet function disorders. Given its high sensitivity, speed and simplicity of use, we conclude that the PFA-100 could replace the in vivo bleeding time as a screening test for primary hemostasis in routine clinical practice.
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Affiliation(s)
- Massimo Franchini
- Servizio di Immunoematologia e Trasfusione, Centro Emofilia, Azienda Ospedaliera di Verona, Verona, Italy.
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28
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Flores A, Buchanan GR. Bleeding severity as an important outcome in childhood immune thrombocytopenia. Pediatr Blood Cancer 2013; 60 Suppl 1:S8-11. [PMID: 23109508 DOI: 10.1002/pbc.24344] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 08/30/2012] [Indexed: 01/19/2023]
Abstract
Over the years pediatric hematologists have continued to debate whether pharmacotherapy or clinical observation should be employed as initial management in childhood immune thrombocytopenia (ITP). Delineating the fundamental elements of heterogeneity in bleeding manifestations in childhood ITP has proven to be a complicated task. Efforts to classify the impact of hemorrhage in ITP based on platelet count have been problematic. Factors beyond relying on a laboratory measurement as a surrogate marker of disease severity need to be considered. What is needed to better guide therapeutic decision-making is a clinically relevant and evidence-based measure of bleeding severity. In this special supplement, the history of therapeutic management in ITP and prior attempts to grade or quantify hemorrhage will be reviewed.
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Affiliation(s)
- Adolfo Flores
- Division of Hematology-Oncology, Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Center for Cancer and Blood Disorders, Children's Medical Center, Dallas, Texas, USA
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29
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Abstract
Abstract
The maturation and postnatal development of the human coagulation system was first studied and described more than 20 years ago. These older studies, supported by more recent data, confirm the significant and important differences in the physiology of coagulation and fibrinolysis in neonates and young children compared with older children and adults. Subsequently, significant differences were also described in the physiology of primary hemostasis and in global in vitro tests for hemostasis. These differences, which mostly reflect the immaturity of the neonatal hemostasis system, are functionally balanced. Healthy neonates show no signs of easy bruising or other bleeding diathesis and no increased tendency to thrombosis for any given stimulus compared with adults. Systemic diseases may affect hemostasis, predisposing ill neonates to increased hemorrhagic or thrombotic complications. The immaturity of the hemostasis system in preterm and very-low-birth-weight neonates may contribute to a higher risk for intraventricular hemorrhage. Therapies targeting the hemostasis system can be effective for preventing and treating these events. The concept of “neonatal coagulopathy” has an important impact on both the diagnosis and management of hemorrhagic or thrombotic events in neonates. For diagnosis of hemostasis disorders, diagnostic laboratories processing pediatric samples should use age-, analyzer-, and reagent-appropriate reference ranges. Age-specific guidelines should be followed for the management of neonates with hemostatic disorders.
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30
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Monagle P, Chan AKC, Goldenberg NA, Ichord RN, Journeycake JM, Nowak-Göttl U, Vesely SK. Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. Chest 2012; 141:e737S-e801S. [PMID: 22315277 DOI: 10.1378/chest.11-2308] [Citation(s) in RCA: 950] [Impact Index Per Article: 79.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
BACKGROUND Neonates and children differ from adults in physiology, pharmacologic responses to drugs, epidemiology, and long-term consequences of thrombosis. This guideline addresses optimal strategies for the management of thrombosis in neonates and children. METHODS The methods of this guideline follow those described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines. RESULTS We suggest that where possible, pediatric hematologists with experience in thromboembolism manage pediatric patients with thromboembolism (Grade 2C). When this is not possible, we suggest a combination of a neonatologist/pediatrician and adult hematologist supported by consultation with an experienced pediatric hematologist (Grade 2C). We suggest that therapeutic unfractionated heparin in children is titrated to achieve a target anti-Xa range of 0.35 to 0.7 units/mL or an activated partial thromboplastin time range that correlates to this anti-Xa range or to a protamine titration range of 0.2 to 0.4 units/mL (Grade 2C). For neonates and children receiving either daily or bid therapeutic low-molecular-weight heparin, we suggest that the drug be monitored to a target range of 0.5 to 1.0 units/mL in a sample taken 4 to 6 h after subcutaneous injection or, alternatively, 0.5 to 0.8 units/mL in a sample taken 2 to 6 h after subcutaneous injection (Grade 2C). CONCLUSIONS The evidence supporting most recommendations for antithrombotic therapy in neonates and children remains weak. Studies addressing appropriate drug target ranges and monitoring requirements are urgently required in addition to site- and clinical situation-specific thrombosis management strategies.
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Affiliation(s)
- Paul Monagle
- Haematology Department, The Royal Children's Hospital, Department of Paediatrics, The University of Melbourne, Murdoch Children's Research Institute, Melbourne, VIC, Australia
| | - Anthony K C Chan
- Department of Pediatrics, McMaster University, Hamilton, ON, Canada
| | - Neil A Goldenberg
- Department of Pediatrics, Section of Hematology/Oncology/Bone Marrow Transplantation and Mountain States Regional Hemophilia and Thrombosis Center, University of Colorado, Aurora, CO
| | - Rebecca N Ichord
- Department of Neurology, Children's Hospital of Philadelphia, Philadelphia, PA
| | - Janna M Journeycake
- Department of Pediatrics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX
| | - Ulrike Nowak-Göttl
- Thrombosis and Hemostasis Unit, Institute of Clinical Chemistry, University Hospital Kiel, Kiel, Germany
| | - Sara K Vesely
- Department of Biostatistics and Epidemiology, University of Oklahoma Health Sciences Center, Oklahoma City, OK.
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Sedky HA, El-Sewefy DA, Saad AA, Ahmed MI, El-Maraghy HMA. Clinical Significance of Baseline Platelet Reactivity in Patients With Acute Coronary Syndrome. Clin Appl Thromb Hemost 2012; 19:256-60. [DOI: 10.1177/1076029612439341] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to assess the baseline platelet hyperactivity in patients with acute coronary syndrome (ACS) and correlate it with the disease severity and clinical outcome. Participants and Methods: This study was conducted on 60 patients with the first attack of non-ST-segment elevation ACS and 30 healthy controls. Patients were subdivided into 2 groups: group I: 40 patients with non-ST-segment elevation myocardial infarction (NSTEMI) and group II: 20 patients with unstable angina. All the studied patients were subjected to baseline platelet function analysis using platelet function analyzer 100 (PFA-100). Results: Group I patients showed significantly lower PFA-100 closure time (CT) than group II ( P = .04) and control group ( P = .03). The occurrence of complications in NSTEMI patients was associated with older age, hypertension, and shorter baseline collagen adenosine diphosphate PFA-100 CT ( P < .05). Conclusion: NSTEMI patients proved to have enhanced platelet function that can be used as a predictor of the outcome.
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Affiliation(s)
| | | | - Abeer A. Saad
- Department of Clinical Pathology, Ain Shams University, Cairo, Egypt
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Ignjatovic V, Kenet G, Monagle P. Developmental hemostasis: recommendations for laboratories reporting pediatric samples. J Thromb Haemost 2012; 10:298-300. [PMID: 22403808 DOI: 10.1111/j.1538-7836.2011.04584.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- V Ignjatovic
- Murdoch Childrens Research Institute, Royal Childrens Hospital, Parkville, Victoria, Australia.
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SLADKY JL, KLIMA J, GROOMS L, KERLIN BA, O’BRIEN SH. The PFA-100® does not predict delta-granule platelet storage pool deficiencies. Haemophilia 2012; 18:626-9. [DOI: 10.1111/j.1365-2516.2011.02733.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Strauss T, Sidlik-Muskatel R, Kenet G. Developmental hemostasis: primary hemostasis and evaluation of platelet function in neonates. Semin Fetal Neonatal Med 2011; 16:301-4. [PMID: 21810548 DOI: 10.1016/j.siny.2011.07.001] [Citation(s) in RCA: 59] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Hemostasis is a dynamic process and physiologic concentrations of coagulation proteins gradually increase with gestational age. Nevertheless, the risk for bleeding in term neonates is counterbalanced by the protective effects of physiologic deficiencies of the inhibitors of coagulation. Although laboratory diagnosis of coagulation disorders in infants may be difficult to establish, due to the need to adapt all assays for small amounts of blood and the age-related interpretation required for test results - evaluation of infants with secondary hemostatic defects is quite feasible, whereas laboratory assessment of primary hemostasis in neonates remains a challenge. While platelet number and volume are similar in neonates as compared to adult values, neonatal platelets certainly exhibit hyporesponsiveness. Analysis of platelet function may include aggregation studies or flow cytometry assays, using fluorescence-stained monoclonal antibodies against platelet membranes and cellular antigens. Data on platelet function in correlation with gestational age are scarce and the duration of platelet hyporeactivity and its clinical significance have not yet been completely elucidated. Whole-blood-based platelet function assays have shown in neonates as well as in premature infants progressive improvement of clot formation with gestational age. This article reviews platelet function, assessed by various techniques, and its development in the premature as well as healthy term neonate.
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Affiliation(s)
- T Strauss
- Neonatology and Pediatric Departments of the Safra Children's Hospital, Tel Hashomer, Israel
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Abstract
The haemostatic system is a complex interaction between the vasculature, cellular components and plasma proteins that interact to maintain haemostasis in the healthy body. The haemostatic system can be further defined as primary, secondary and tertiary haemostasis to better define the interdependent mechanisms that combine to maintain haemostasis. The term 'developmental haemostasis' was first introduced by Maureen Andrews in the 1980s to describe the age-related physiological changes of the coagulation system as it develops progressively over time from fetal, neonatal, paediatric to adult and geriatric systems. This paper will focus on developmental changes in secondary haemostasis, that is, the plasma protein changes that occur with age, particularly during the fetal and neonatal period, when the changes are most marked compared to the adult system.
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Affiliation(s)
- Paul Monagle
- Department of Clinical Haematology, Royal Children's Hospital, Melbourne, Australia.
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36
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Microparticles in newborn cord blood: Slight elevation after normal delivery. Thromb Res 2011; 128:62-7. [DOI: 10.1016/j.thromres.2011.01.013] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2010] [Revised: 12/28/2010] [Accepted: 01/31/2011] [Indexed: 11/18/2022]
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37
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Platelet function in dogs with congenital portosystemic shunt. Vet J 2011; 188:189-92. [DOI: 10.1016/j.tvjl.2010.04.002] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2009] [Revised: 04/07/2010] [Accepted: 04/08/2010] [Indexed: 11/22/2022]
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Feuring M, Wehling M, Burkhardt H, Schultz A. Coagulation status in coronary artery disease patients with type II diabetes mellitus compared with non-diabetic coronary artery disease patients using the PFA-100® and ROTEM®. Platelets 2010; 21:616-22. [PMID: 20807172 DOI: 10.3109/09537104.2010.504868] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Previous investigations in patients with coronary artery disease (CAD) revealed differences in thromboelastographic parameters indicating different states of coagulability. The aim of the present study was to investigate the coagulation status of patients with documented CAD and type II diabetes mellitus (DM) and non-diabetic patients with coronary artery disease with the PFA-100® and the ROTEM®. No differences were found in platelet function as measured with collagen/epinephrine (263.6 ± 70.6 s vs. 254.6 ± 65.3 s) and collagen/ADP cartridges (105.3 ± 63.2 s vs. 90.6 ± 47.3 s) in CAD patients with DM and CAD patients without DM. Measured with the EXTEM reagent of the ROTEM®, mean maximum clot elasticity (MCE) in patients with CAD and DM (233.6 ± 86.9) was significantly longer than in CAD patients without DM (186.7 ± 54.5), (p = 0.03). A similar result was seen using the INTEM reagent; patients with CAD and DM (234.4 ± 83.9) showed a higher value for MCE than CAD patients without DM (190.8 ± 57.8) which was of borderline significance (p = 0.053). Moreover, a weak trend for higher maximum clot firmness (MCF) was seen in CAD patients with DM compared with CAD patients without DM with the EXTEM reagent (68.1 ± 7.5 vs. 63.6 ± 8.6, p = 0.08) and the INTEM reagent (68.4 ± 7.2 vs. 64.1 ± 8.2, p = 0.09). The ROTEM® analysis indicates increased coagulability in patients with coronary artery disease and diabetes mellitus compared to non-diabetic CAD patients. Moreover, the ROTEM® device seems to be an appropriate and easy-to-use tool to describe the coagulation status in these patients groups.
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Affiliation(s)
- M Feuring
- Institute of Experimental and Clinical Pharmacology and Toxicology, Medical Faculty Mannheim, University of Heidelberg, Germany
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39
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Antiplatelet therapy in pediatric cardiovascular patients. Pediatr Cardiol 2010; 31:454-61. [PMID: 20213092 DOI: 10.1007/s00246-010-9672-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2010] [Accepted: 02/08/2010] [Indexed: 02/04/2023]
Abstract
Platelets play a critical role in normal physiologic processes such as hemostasis, wound healing, inflammation, and innate immunity. However, they also play a role in the pathologic process of thrombosis. Although antiplatelet therapy is most commonly used to prevent thrombotic events for adults with atherosclerotic vascular disease, children with certain types of congenital heart disease, stroke, and Kawasaki disease also are at risk for thrombosis and may benefit from antiplatelet therapy. Unfortunately, very little data on the efficacy and safety of antiplatelet therapy for pediatric patients are available. As a consequence, consistent clinical practice among pediatric practitioners is lacking. Furthermore, much of what is practiced results from extrapolation from adult studies, which may be problematic because many aspects of platelet biology differ between children and adults. This review discusses aspects of antiplatelet therapy for pediatric patients.
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Revel-Vilk S, Varon D, Shai E, Agmon Y, Hyam E, Daas N, Miskin H, Weintraub M. Evaluation of children with a suspected bleeding disorder applying the Impact-R [Cone and Plate(let) Analyzer]. J Thromb Haemost 2009; 7:1990-6. [PMID: 19799714 DOI: 10.1111/j.1538-7836.2009.03628.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/31/2023]
Abstract
BACKGROUND A convenient screening test for children with bleeding symptoms before more labor-intensive diagnostic steps are taken would be of value. The Impact-R was designed in an attempt to analyse platelet function under near physiological conditions. Results are presented as surface coverage (SC, %) and average size (AS, microm(2)). OBJECTIVE In this cross-sectional retrospective study, we assessed the use of the Impact-R in the evaluation of children with a suspected bleeding disorder (BD). METHODS The hospital charts of 110 children referred to the coagulation laboratory were reviewed for personal and family bleeding history (BH) as well as results of the laboratory evaluation. RESULTS A laboratory 'diagnosable' BD (LBD) was found in 23 children (21%, 95% CI 14-30%). A diagnosis of LBD was associated with the severity of bleeding but not with family BH. By receiver-operating characteristic (ROC) curve analysis, the SC was superior to the AS for diagnosis of a LBD. The Impact-R was abnormal in 43/97 children (44.3%, 95% CI 34-55%). The predictive values of a normal and abnormal Impact-R were 96% (95% CI 92-97%) and 42% (95% CI 28-56%), respectively. When considering the personal and family BH, the post-test probability for LBD after a normal Impact-R was reduced from 20% to 3.5% (95% CI 2.5-7%). CONCLUSIONS A normal Impact-R test is highly effective in excluding LBDs. Yet, in case of an abnormal Impact-R test, further testing is needed. An algorithm that includes the personal and family BH and the results of a screening test may improve the diagnostic process. Prospective studies are now needed to confirm these findings.
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Affiliation(s)
- S Revel-Vilk
- Pediatric Hematology/Oncology Department, Hadassah Hebrew-University Hospital, Jerusalem, Israel.
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41
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Karger R, Donner-Banzhoff N, Müller HH, Kretschmer V, Hunink M. Diagnostic performance of the platelet function analyzer (PFA-100®) for the detection of disorders of primary haemostasis in patients with a bleeding history–a systematic review and meta-analysis. Platelets 2009; 18:249-60. [PMID: 17538845 DOI: 10.1080/09537100601100366] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
The Platelet Function Analyzer (PFA-100) is increasingly being used in the workup of patients with a bleeding diathesis. A profound knowledge of the possible diagnostic performance of this test is essential in order to make sound clinical decisions based on its results. It was the aim of this study to systematically review the published literature and provide valid estimates of the diagnostic performance of the PFA-100 for detecting disorders of primary haemostasis in newly presenting patients with a bleeding diathesis. A comprehensive literature search was performed for studies published between January 1994 and February 2006. Studies were eligible for the systematic review if they provided data supposed to be applicable to the determination of the diagnostic performance of the PFA-100. Furthermore, they were included in a meta-analysis if study reporting allowed calculation of sensitivity and specificity and if study quality ensured minimized biases of these estimates for the described clinical setting. Pooled weighted sensitivity, specificity and diagnostic odds ratio were calculated applying random effects modelling and constructing summary operator characteristic curves. This was done separately for the available test modifications using either collagen/epinephrine (PFA-EPI) or collagen/adenosine-diphosphate (PFA-ADP) for platelet activation. Thirty-six articles were included in the systematic review. Six studies met our eligibility criteria for a meta-analysis. The major reason for exclusion from the meta-analysis was a case-control design. A total of 1486 and 1259 patients were included in the meta-analysis of the diagnostic performance of the PFA-EPI and PFA-ADP, respectively. Pooled weighted sensitivity and specificity of the PFA-EPI/PFA-ADP in detecting a disorder of primary haemostasis were: 82.5/66.9% (95%-confidence interval (95%-CI): 76.0-88.9%/57.9-75.9%), and 88.7/85.5% (95%-CI: 84.3-93.1%/82.0-89.1%). 83/75% of patients with a positive PFA-EPI/PFA-ADP result do have a disorder of primary haemostasis whereas 88/79% with a negative PFA-EPI/PFA-ADP result do not. The PFA-EPI appeared to have a higher sensitivity and better predictive values than the PFA-ADP in detecting disorders of primary haemostasis, although a rigorous gold standard definition for a disorder of primary haemostasis, particularly for platelet disorders, was not applied in most studies. The majority of the studies lacked important requirements for quality and reporting, precluding a more precise and definitive characterization of the clinical utility of the PFA-100. This emphasizes the need for an evidence-based critical appraisal of diagnostic studies in haemostasis research in order to promote the conducting of studies that produce clinically relevant results.
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Affiliation(s)
- Ralf Karger
- Institute for Transfusion Medicine and Haemostaseology, Philipps University, Marburg, Germany.
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42
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Towards a Rationale of Platelet Aggregation Monitoring in Stroke Prophylaxis? J Stroke Cerebrovasc Dis 2009; 18:111-5. [DOI: 10.1016/j.jstrokecerebrovasdis.2008.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2008] [Revised: 09/02/2008] [Accepted: 09/11/2008] [Indexed: 11/22/2022] Open
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Bernhard H, Rosenkranz A, Petritsch M, Köfeler H, Rehak T, Novak M, Muntean W. Phospholipid content, expression and support of thrombin generation of neonatal platelets. Acta Paediatr 2009; 98:251-5. [PMID: 18976372 DOI: 10.1111/j.1651-2227.2008.01075.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
AIM Newborns have, despite low clotting factors and poor in vitro platelet function, a well functioning haemostasis. We investigated whether phospholipids (PL) in neonatal platelets differ from those in adult platelets in their exposure on the platelet surface, and their effect on thrombin generation. METHODS The effect of newborn and adult platelets on thrombin generation (TG) was measured by means of calibrated automated thrombography (CAT), and in a purified system. In addition, clotting times were measured. Phosphatidylserine (PS)-exposure was measured by flow cytometry. The amount of PL was determined by means of mass-spectrometry (Materials and Methods section in Supporting Information online). RESULTS In comparison with adults the clotting times in platelet-rich plasma of newborns were less shortened by adding calciumionophore. No differences in the support of TG between neonatal and adult platelets were found by means of CAT. In the purified system, TG was increased by ionophor-stimulated platelets but no difference was evident between newborn and adult platelets. Flow cytometric analysis showed no difference between adult and newborn platelets. Results of mass-spectrometry showed a very similar pattern of phospholipid-content of adult and newborn platelets. CONCLUSION Our results do not provide any evidence that a different phospholipid-expression of neonatal platelets may alter TG in neonates.
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Affiliation(s)
- Heike Bernhard
- Department of Pediatrics, Medical University of Graz, Austria
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Monagle P, Chalmers E, Chan A, deVeber G, Kirkham F, Massicotte P, Michelson AD. Antithrombotic therapy in neonates and children: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Chest 2008; 133:887S-968S. [PMID: 18574281 DOI: 10.1378/chest.08-0762] [Citation(s) in RCA: 415] [Impact Index Per Article: 25.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This chapter about antithrombotic therapy in neonates and children is part of the Antithrombotic and Thrombolytic Therapy: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition). Grade 1 recommendations are strong and indicate that the benefits do, or do not, outweigh risks, burden, and costs, and Grade 2 suggests that individual patient values may lead to different choices (for a full understanding of the grading, see Guyatt et al in this supplement, pages 123S-131S). In this chapter, many recommendations are based on extrapolation of adult data, and the reader is referred to the appropriate chapters relating to guidelines for adult populations. Within this chapter, the majority of recommendations are separate for neonates and children, reflecting the significant differences in epidemiology of thrombosis and safety and efficacy of therapy in these two populations. Among the key recommendations in this chapter are the following: In children with first episode of venous thromboembolism (VTE), we recommend anticoagulant therapy with either unfractionated heparin (UFH) or low-molecular-weight heparin (LMWH) [Grade 1B]. Dosing of IV UFH should prolong the activated partial thromboplastin time (aPTT) to a range that corresponds to an anti-factor Xa assay (anti-FXa) level of 0.35 to 0.7 U/mL, whereas LMWH should achieve an anti-FXa level of 0.5 to 1.0 U/mL 4 h after an injection for twice-daily dosing. In neonates with first VTE, we suggest either anticoagulation or supportive care with radiologic monitoring and subsequent anticoagulation if extension of the thrombosis occurs during supportive care (Grade 2C). We recommend against the use of routine systemic thromboprophylaxis for children with central venous lines (Grade 1B). For children with cerebral sinovenous thrombosis (CSVT) without significant intracranial hemorrhage (ICH), we recommend anticoagulation initially with UFH, or LMWH and subsequently with LMWH or vitamin K antagonists (VKAs) for a minimum of 3 months (Grade 1B). For children with non-sickle-cell disease-related acute arterial ischemic stroke (AIS), we recommend UFH or LMWH or aspirin (1 to 5 mg/kg/d) as initial therapy until dissection and embolic causes have been excluded (Grade 1B). For neonates with a first AIS, in the absence of a documented ongoing cardioembolic source, we recommend against anticoagulation or aspirin therapy (Grade 1B).
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Affiliation(s)
- Paul Monagle
- From the Haematology Department, The Royal Children's Hospital and Department of Pathology, The University of Melbourne, Melbourne, VIC, Australia.
| | - Elizabeth Chalmers
- Consultant Pediatric Hematologist, Royal Hospital for Sick Children, Glasgow, UK
| | | | - Gabrielle deVeber
- Division of Neurology, Hospital for Sick Children, Toronto, ON, Canada
| | | | - Patricia Massicotte
- Department of Pediatrics, Stollery Children's Hospital, Edmonton, AB, Canada
| | - Alan D Michelson
- Center for Platelet Function Studies, University of Massachusetts Medical School, Worcester, MA
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García Cubero M, Rodríguez Morales D, Burgoa Alcalaya B. Resistencia al ácido acetilsalicílico y sus repercusiones clínicas. Semergen 2008. [DOI: 10.1016/s1138-3593(08)71890-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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Perel J, Just S, Rowell J, Williams B, Kennedy G. Utility of the PFA-100®analyser in the evaluation of primary haemostasis in a paediatric population. Int J Lab Hematol 2007; 29:480-1. [DOI: 10.1111/j.1751-553x.2007.00882.x] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Homoncik M, Gessl A, Ferlitsch A, Jilma B, Vierhapper H. Altered platelet plug formation in hyperthyroidism and hypothyroidism. J Clin Endocrinol Metab 2007; 92:3006-12. [PMID: 17488803 DOI: 10.1210/jc.2006-2644] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
OBJECTIVE Patients with thyroid diseases have abnormalities of blood coagulation including an alteration of von Willebrand factor (vWF) levels. Because vWF plays an important role in primary hemostasis, we hypothesized that heightened and decreased vWF levels in hyper- and hypothyroidism enhance and decrease platelet plug formation, respectively. METHODS We followed a cohort of 120 patients with overt hyperthyroidism, patients with subclinical and overt hypothyroidism, and euthyroid controls. vWF and in vitro platelet plug formation as collagen-epinephrine-induced closure time (CEPI-CT) were measured at baseline and during therapy with thiamazole or T(4). RESULTS Baseline vWF levels were higher in patients with hyperthyroidism and lower in patients with overt hypothyroidism than in controls (P < 0.01). High vWF antigen levels were associated with increased baseline platelet plug formation in patients with hyperthyroidism as compared with controls [114 sec (95% confidence interval, 105-122 sec) vs. 130 sec (120-140 sec), P = 0.01]. After 8 wk of therapy with thiamazole, serum concentrations of T(4) and vWF levels decreased to normal values (P < 0.01 vs. baseline), and CEPI-CT was prolonged as compared with baseline (P < 0.01). During therapy with T(4), vWF levels increased (P < 0.05 vs. baseline) and CEPI-CT was shortened as compared with baseline (P < 0.01). CONCLUSION Hyperthyroidism-induced vWF elevation is associated with enhanced platelet function and therefore shortened CEPI-CT values. These changes may contribute to the higher risk for cardiovascular disease in patients with hyperthyroidism. Platelet plug formation decreases during therapy with thiamazole. Furthermore, CEPI-CT appears to be sensitive to detect acquired von Willebrand disease associated with overt hypothyroidism.
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Affiliation(s)
- Monika Homoncik
- Department of Internal Medicine IV, Medical University of Vienna, Austria
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49
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The Platelet Function Analyzer (PFA)-100. Platelets 2007. [DOI: 10.1016/b978-012369367-9/50790-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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50
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Israels SJ. Platelet Function in the Newborn. Platelets 2007. [DOI: 10.1016/b978-012369367-9/50784-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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