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Platelets in the neonate: Not just a small adult

Neonates, particularly those born preterm, have a high incidence of thrombocytopenia and bleeding, most commonly in the brain. Because of this, it has historically been accepted that neonates should be transfused at higher platelet counts than older children or adults, to decrease their bleeding ris...

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Autores principales: Davenport, Patricia, Sola‐Visner, Martha
Formato: Online Artículo Texto
Lenguaje:English
Publicado: John Wiley and Sons Inc. 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9102610/
https://www.ncbi.nlm.nih.gov/pubmed/35592812
http://dx.doi.org/10.1002/rth2.12719
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author Davenport, Patricia
Sola‐Visner, Martha
author_facet Davenport, Patricia
Sola‐Visner, Martha
author_sort Davenport, Patricia
collection PubMed
description Neonates, particularly those born preterm, have a high incidence of thrombocytopenia and bleeding, most commonly in the brain. Because of this, it has historically been accepted that neonates should be transfused at higher platelet counts than older children or adults, to decrease their bleeding risk. However, a number of observational studies and a recent large, randomized trial found a higher incidence of bleeding and mortality in neonates who received more platelet transfusions. The mechanisms underlying the deleterious effects of platelet transfusions in neonates are unknown, but it has been hypothesized that transfusing adult platelets into the very different physiological environment of a neonate may result in a “developmental mismatch” with potential negative consequences. Specifically, neonatal platelets are hyporeactive in response to multiple agonists and upon activation express less surface P‐selectin than adult platelets. However, this hyporeactivity is well balanced by factors in neonatal blood that promote clotting, such as the elevated hematocrit, elevated von Willebrand factor (VWF) levels, and a predominance of ultra‐long VWF polymers, with the net result of normal neonatal primary hemostasis. So far, most studies on the developmental differences between neonatal and adult platelets have focused on their hemostatic functions. However, it is now clear that platelets have important nonhemostatic functions, particularly in angiogenesis, immune responses, and inflammation. Whether equally important developmental differences exist with regard to those nonhemostatic platelet functions and how platelet transfusions perturb those processes in neonates remain unanswered questions.
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spelling pubmed-91026102022-05-18 Platelets in the neonate: Not just a small adult Davenport, Patricia Sola‐Visner, Martha Res Pract Thromb Haemost State of the Art Isth 2021 Neonates, particularly those born preterm, have a high incidence of thrombocytopenia and bleeding, most commonly in the brain. Because of this, it has historically been accepted that neonates should be transfused at higher platelet counts than older children or adults, to decrease their bleeding risk. However, a number of observational studies and a recent large, randomized trial found a higher incidence of bleeding and mortality in neonates who received more platelet transfusions. The mechanisms underlying the deleterious effects of platelet transfusions in neonates are unknown, but it has been hypothesized that transfusing adult platelets into the very different physiological environment of a neonate may result in a “developmental mismatch” with potential negative consequences. Specifically, neonatal platelets are hyporeactive in response to multiple agonists and upon activation express less surface P‐selectin than adult platelets. However, this hyporeactivity is well balanced by factors in neonatal blood that promote clotting, such as the elevated hematocrit, elevated von Willebrand factor (VWF) levels, and a predominance of ultra‐long VWF polymers, with the net result of normal neonatal primary hemostasis. So far, most studies on the developmental differences between neonatal and adult platelets have focused on their hemostatic functions. However, it is now clear that platelets have important nonhemostatic functions, particularly in angiogenesis, immune responses, and inflammation. Whether equally important developmental differences exist with regard to those nonhemostatic platelet functions and how platelet transfusions perturb those processes in neonates remain unanswered questions. John Wiley and Sons Inc. 2022-05-13 /pmc/articles/PMC9102610/ /pubmed/35592812 http://dx.doi.org/10.1002/rth2.12719 Text en © 2022 The Authors. Research and Practice in Thrombosis and Haemostasis published by Wiley Periodicals LLC on behalf of International Society on Thrombosis and Haemostasis (ISTH). https://creativecommons.org/licenses/by-nc-nd/4.0/This is an open access article under the terms of the http://creativecommons.org/licenses/by-nc-nd/4.0/ (https://creativecommons.org/licenses/by-nc-nd/4.0/) License, which permits use and distribution in any medium, provided the original work is properly cited, the use is non‐commercial and no modifications or adaptations are made.
spellingShingle State of the Art Isth 2021
Davenport, Patricia
Sola‐Visner, Martha
Platelets in the neonate: Not just a small adult
title Platelets in the neonate: Not just a small adult
title_full Platelets in the neonate: Not just a small adult
title_fullStr Platelets in the neonate: Not just a small adult
title_full_unstemmed Platelets in the neonate: Not just a small adult
title_short Platelets in the neonate: Not just a small adult
title_sort platelets in the neonate: not just a small adult
topic State of the Art Isth 2021
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9102610/
https://www.ncbi.nlm.nih.gov/pubmed/35592812
http://dx.doi.org/10.1002/rth2.12719
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