title: Effects of in vitro adult platelet transfusions on neonatal hemostasis.
abstract: BACKGROUND
  Thrombocytopenia is frequent among neonates, and 20-25% of affected infants are treated with platelet transfusions. These are frequently given for mild thrombocytopenia (platelets: 50-100 × 10(9) L(-1)), largely because of the known hyporeactivity of neonatal platelets. In tests of primary hemostasis, however, neonates have shorter bleeding and closure times (CTs) than adults. This has been attributed to their higher hematocrits, higher von Willebrand factor (VWF) concentrations, and predominance of longer VWF polymers.
  
  
  OBJECTIVE
  To determine whether the 'transfusion' of adult (relatively hyperreactive) platelets into neonatal blood results in a hypercoagulable profile.
  
  
  METHODS
  Cord blood (CB) and adult peripheral blood (PB) were separated (with a modified buffy coat method) to generate miniaturized platelet concentrates (PCs) and thrombocytopenic blood. PB-derived and CB-derived PCs (n = 7 per group) were then 'transfused'in vitro into thrombocytopenic CB and PB. The effects of autologous vs. allogeneic (developmentally mismatched) 'transfusions' were evaluated with whole blood aggregometry, a platelet function analyzer (PFA-100), and thromboelastography (TEG).
  
  
  RESULTS
  Adult platelets aggregated significantly better than neonatal platelets in response to thrombin receptor-activating peptide, ADP, and collagen, regardless of the blood into which they were transfused. The 'transfusion' of adult platelets into thrombocytopenic CB resulted in shorter CTs-EPI (PFA-100) and higher clot strength and firmness (TEG) than 'transfusion' of neonatal autologous platelets.
  
  
  CONCLUSIONS
  In vitro'transfusion' of adult platelets into neonatal blood results in shorter CTs than 'transfusion' with neonatal platelets. Our findings should raise awareness of the differences between the neonatal and adult hemostatic system and the potential 'developmental mismatch' associated with platelet transfusions for neonatal hemostasis.
authors.affiliation: Division of Newborn Medicine, Children's Hospital Boston and Harvard Medical School, Boston, MA 02115, USA.
authors.forename: F
authors.initials: F
authors.lastname: Ferrer-Marin
authors.forename: C
authors.initials: C
authors.lastname: Chavda
authors.forename: M
authors.initials: M
authors.lastname: Lampa
authors.forename: A D
authors.initials: AD
authors.lastname: Michelson
authors.forename: A L
authors.initials: AL
authors.lastname: Frelinger
authors.forename: M
authors.initials: M
authors.lastname: Sola-Visner
mesh_terms: D000328:Adult; D001760:Bleeding Time; D001777:Blood Coagulation; D001792:Blood Platelets / Q000166:cytology; D005312:Fetal Blood / Q000166:cytology; D006400:Hematocrit; D006487:Hemostasis; D006801:Humans; D066298:In Vitro Techniques; D007231:Infant, Newborn; D010974:Platelet Aggregation; D010976:Platelet Count; D010979:Platelet Function Tests; D017713:Platelet Transfusion / Q000379:methods*; D013916:Thrombelastography / Q000379:methods; D013921:Thrombocytopenia / Q000628:therapy*