The PFA-100 system successfully detected platelet dysfunction caused by impairment of von Willebrand factor or inhibition of glycoprotein Ib or IIb/IIIa receptors via abnormal closure times.
The PFA-100 system provides a rapid, accurate in vitro measure of platelet function by assessing closure time under high shear conditions.
A new in vitro system for the detection of platelet dysfunction, PFA-100, has been developed. It provides a quantitative measure of platelet function in anticoagulated whole blood. The system comprises a microprocessor-controlled instrument and a disposable test cartridge containing a biologically active membrane. The instrument aspirates a blood sample under constant vacuum from the sample reservoir through a capillary and a microscopic aperture cut into the membrane. The membrane is coated with collagen and epinephrine or adenosine 5'-diphosphate. The presence of these biochemical stimuli, and the high shear rates generated under the standardized flow conditions, result in platelet attachment, activation, and aggregation, slowly building a stable platelet plug at the aperture. The time required to obtain full occlusion of the aperture is reported as the "closure time." We have found that impairment of von Willebrand factor, or inhibition of platelet receptors glycoprotein Ib or IIb/IIIa with monoclonal antibodies or peptides, resulted in abnormal closure times. An antifibrinogen antibody, in contrast, failed to show any effect. The test appears to be sensitive to platelet adherence and aggregation abnormalities. The PFA-100 system has potential applications in routine evaluation of platelet function in the clinical setting because of its accuracy, ease of operation, and rapid turnaround of results.
Kundu et al. (Wed,) conducted a other in Platelet dysfunction. PFA-100 system was evaluated on Closure time. The PFA-100 system successfully detected platelet dysfunction caused by impairment of von Willebrand factor or inhibition of glycoprotein Ib or IIb/IIIa receptors via abnormal closure times.