title: Precision and reliability of 5 platelet function tests in healthy volunteers and donors on daily antiplatelet agent therapy.
abstract: BACKGROUND
  Anticoagulation protocols used during mechanical circulatory support call for titration of antiplatelet agents. We compared the precision and reliability of 5 platelet function tests in healthy volunteers and donors on daily antiplatelet therapy to distinguish their efficacy for titrating antiplatelet therapy.
  
  
  METHODS
  We assessed arachidonic acid-induced platelet function by light transmission aggregometry (LTA), Multiplate impedance aggregometry, VerifyNow, and platelet mapping by thromboelastography (TEG PM). We assessed ADP-induced platelet function by the same methods and flow cytometry. Forty healthy volunteers and 10-13 volunteers on daily aspirin and/or clopidogrel therapy were evaluated. We compared tests for intraassay precision, interassay precision (samples from 2 separate blood draws), and reliability coefficient.
  
  
  RESULTS
  For arachidonic acid-induced platelet aggregation in healthy volunteers, intra- and interassay CVs were ≤ 10% for all methods. Intra- and interassay precision among donors on daily aspirin was ≤ 30% for all methods except LTA (38% interassay CV) and TEG PM (95% intraassay and 104% interassay CV). For ADP-induced platelet function, intra- and interassay precision was ≤ 10% and ≤ 30% for all methods. Only Multiplate demonstrated moderate or greater (R > 0.40) reliability coefficients for arachidonic acid-induced platelet function among all subjects. All methods of ADP-induced platelet function, except TEG PM, demonstrated substantial or greater (R > 0.60) reliability among all subjects.
  
  
  CONCLUSIONS
  TEG PM is least suited to monitor effects of antiplatelet agents. Multiplate impedance aggregometry was the only method to demonstrate an acceptable reliability coefficient among healthy volunteers and donors on both aspirin and clopidogrel therapy.
authors.affiliation: Department of Laboratory Medicine and Pathology and karon.bradley@mayo.edu.
authors.forename: Brad S
authors.initials: BS
authors.lastname: Karon
authors.affiliation: Current address: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.
authors.forename: Nicole V
authors.initials: NV
authors.lastname: Tolan
authors.affiliation: Department of Laboratory Medicine and Pathology and.
authors.forename: Christopher D
authors.initials: CD
authors.lastname: Koch
authors.affiliation: Department of Laboratory Medicine and Pathology and.
authors.forename: Amy M
authors.initials: AM
authors.lastname: Wockenfus
authors.affiliation: Department of Laboratory Medicine and Pathology and.
authors.forename: Randall S
authors.initials: RS
authors.lastname: Miller
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, MN;
authors.forename: Ravi K
authors.initials: RK
authors.lastname: Lingineni
authors.affiliation: Department of Laboratory Medicine and Pathology and.
authors.forename: Rajiv K
authors.initials: RK
authors.lastname: Pruthi
authors.affiliation: Department of Laboratory Medicine and Pathology and.
authors.forename: Dong
authors.initials: D
authors.lastname: Chen
authors.affiliation: Department of Laboratory Medicine and Pathology and.
authors.forename: Allan S
authors.initials: AS
authors.lastname: Jaffe
mesh_terms: D016718:Arachidonic Acid / Q000494:pharmacology; D001241:Aspirin / Q000008:administration & dosage / Q000627:therapeutic use*; D000077144:Clopidogrel; D005260:Female; D064368:Healthy Volunteers; D006801:Humans; D008297:Male; D010974:Platelet Aggregation / Q000187:drug effects*; D010975:Platelet Aggregation Inhibitors / Q000008:administration & dosage / Q000627:therapeutic use*; D010979:Platelet Function Tests / Q000592:standards*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013988:Ticlopidine / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000627:therapeutic use
chemical_list: D010975:Platelet Aggregation Inhibitors; D016718:Arachidonic Acid; D000077144:Clopidogrel; D013988:Ticlopidine; D001241:Aspirin