Pre-4: Qualitative Disorders of Platelets Flashcards
Optical Platelet Aggregometry
Sample:
PRP
Optical Platelet Aggregometry
Principle
Light Transmittance
Whole Blood Aggregometry:
Sample
Whole blood
Whole Blood Aggregometry:
Principle
Electrical impedance
Platelet Lumi Aggregometry:
Sample
Both WB & PRP
Platelet Lumi Aggregometry:
Principle
Chemiluminescence
As platelets aggregates form, more light passes through the PRP and the tracing begins to move toward 100% light transmittance.
Optical Platelet Aggregometry
As Platelet aggregate, platelets collect on the electrodes impeding the current. The change is amplified and recorded.
Whole Blood Aggregometry
Reagent added in Platelet Lumi Aggregometry
Luciferin-luciferase enzyme
Biphasic Curve agonists:
Thrombin
ADP
Epinephrine
Monophasic Curve agonists:
Collagen
Arachidonic acid
Ristocetin
RECEPTORS of Thrombin
PAR-1, PAR4;
GPIba & GPVI
Receptors of ADP
P2Y1 & P2Y12
Receptors of Epinephrine
A2- Adrenergic receptor
Receptors of Collagen
GPIa/GPIIa & GPVI
Receptors of Arachidonic acid
TPa and TPb
Receptors of Ristocetin
GPIb/IX/V with vWF
GP Ib/IX/V complex is missing ‘
Bernard-Soulier Syndrome (Giant Platelet Syndrome)
Inability to bind to vWF accounts for the inability of platelet to adhere to exposed sub endothelium and results to the bleeding characteristics
Bernard-Soulier Syndrome (Giant Platelet Syndrome)
Laboratory feature: Giant Platelets
Bernard-Soulier Syndrome (Giant Platelet Syndrome)
Aggregometry: No aggregation to Ristocetin
Bernard-Soulier Syndrome (Giant Platelet Syndrome)
Deficiency/abnormality of GPIIb/IIIa
Glanzmann Thrombasthenia
Dense Granule Deficiency
- Hermansky-Pudlak Syndrome
- Chediak-Higashi Syndrome
- Wiskot-Aldrich Syndrome
- Thrombocytopenia Absent Radius (TAR) Syndrome
Alpha Granule Deficiency
Gray Platelet Syndrome