title: Alterations of platelet function and clot formation kinetics after in vitro exposure to anti-A and -B.
abstract: BACKGROUND
  ABO-mismatched platelets (PLTs) are commonly transfused despite reported complications. We hypothesized that because PLTs possess A and B antigens on their surface, ABO-mismatched transfused or recipient PLTs could become activated and/or dysfunctional after exposure to anti-A or -B in the transfused or recipient plasma. We present here in vitro modeling data on the functional effects of exposure of PLTs to ABO antibodies.
  
  
  METHODS
  PLT functions of normal PLTs of all ABO types were assessed before and after incubation with normal saline, ABO-identical plasma samples, or O plasma samples with varying titers of anti-A and anti-B (anti-A/B). Assays used for this assessment include PLT aggregation, clot kinetics, thrombin generation, PLT cytoskeletal function, and mediator release.
  
  
  RESULTS
  Exposure of antigen-bearing PLTs to O plasma with moderate to high titers of anti-A/B significantly inhibits aggregation, prolongs PFA-100 epinephrine closure time, disrupts clot formation kinetics, accelerates thrombin generation, reduces total thrombin production, alters PLT cytoskeletal function, and influences proinflammatory and prothrombotic mediator release.
  
  
  CONCLUSIONS
  Our findings demonstrate a wide range of effects that anti-A/B have on PLT function, clot formation, thrombin generation, PLT cytoskeletal function, and mediator release. These data provide potential explanations for clinical observations of increased red blood cell utilization in trauma and surgical patients receiving ABO-nonidentical blood products. Impaired hemostasis caused by anti-A/B interacting with A and B antigens on PLTs, soluble proteins, and perhaps even endothelial cells is a potential contributing factor to hemorrhage in patients receiving larger volumes of ABO-nonidentical transfusions.
authors.affiliation: Department of Pathology and Laboratory Medicine, the James P. Wilmot Cancer Center, University of Rochester, Rochester, New York 14642, USA. majed_refaai@urmc.rochester.edu
authors.forename: Majed A
authors.initials: MA
authors.lastname: Refaai
authors.forename: Jessie
authors.initials: J
authors.lastname: Carter
authors.forename: Kelly F
authors.initials: KF
authors.lastname: Henrichs
authors.forename: Donna C
authors.initials: DC
authors.lastname: Davidson
authors.forename: Stephen J
authors.initials: SJ
authors.lastname: Pollock
authors.forename: Ann E
authors.initials: AE
authors.lastname: Casey
authors.forename: Sherry L
authors.initials: SL
authors.lastname: Spinelli
authors.forename: Richard P
authors.initials: RP
authors.lastname: Phipps
authors.forename: Charles W
authors.initials: CW
authors.lastname: Francis
authors.forename: Neil
authors.initials: N
authors.lastname: Blumberg
mesh_terms: D000017:ABO Blood-Group System / Q000276:immunology*; D000328:Adult; D000906:Antibodies / Q000494:pharmacology*; D001777:Blood Coagulation / Q000187:drug effects* / Q000502:physiology; D001788:Blood Grouping and Crossmatching; D001792:Blood Platelets / Q000187:drug effects* / Q000276:immunology / Q000502:physiology*; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D008875:Middle Aged; D010974:Platelet Aggregation / Q000187:drug effects / Q000502:physiology; D013997:Time Factors; D017186:Titrimetry
chemical_list: D000017:ABO Blood-Group System; D000906:Antibodies