PFA-100


The PFA-100 is a platelet function analyser that aspirates blood in vitro from a blood specimen into disposable test cartridges through a microscopic aperture cut into a biologically active membrane at the end of a capillary. The membrane of the cartridges are coated with collagen and adenosine diphosphate or collagen and epinephrine inducing a platelet plug to form which closes the aperture.
The PFA test result is dependent on platelet function, plasma Von [Willebrand factor|von Willebrand Factor] level, platelet
number, and the hematocrit.
The PFA test is initially performed with the Collagen/Epinepherine membrane. A normal Col/Epi closure time
excludes the presence of a significant platelet function defect.
If the Col/Epi closure time is prolonged, the Col/ADP test is automatically
performed. If the Col/ADP result is normal, aspirin-induced platelet dysfunction is
most likely.
Prolongation of both test results may indicate
the following;
  • Anemia
  • Thrombocytopenia
  • A significant platelet function defect other than aspirin
Once anemia and thrombocytopenia have been excluded, further evaluation to exclude von
Willebrand disease and inherited/acquired platelet dysfunction can be made.