HEMA 2 - PLATELETS (function tests) Flashcards
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: In vivo screening test
Advantages: Physiological
Disadvantages: Insensitive, invasive and high inter-operator CV
Bleeding Time
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Responsive to panel of agonsists
Advantages: Diagnostic
Disadvantages: Labour intensive non-physiological
Aggregometry - turbidometric methods
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Responsive to panel of agonists
Advantages: Whole blood test
Disadvantages: Insensitive
Aggregometry - impedance methods
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Combined aggregation and ADP release
Advantages: More information
Disadvantages: Semi-quantitative
Aggregometry and luminescence
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Stored and released ADP
Advantages: Sensitive
Disadvantages: Specialised equipment
Adenine nucleotides
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Ultrastructural evaluation of platelets e.g dense granular defects or giant platelet disorders
Advantages: Diagnostic
Disadvantages: Specialised equipment
Electron Microscope
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Glycoprotein defects
Advantages: Simple
Disadvantages: Limited to major glycoproteins
Electrophoretic analysis
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Measures platelet interaction with fibrinogen/fibrin. Detects abnormalities in number, Gp IIb/IIIa, signalling and Fg.
Advantages: Simple
Disadvantages: Not specific
Clot retraction
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Global haemostasis
Advantages: Predicts bleeding
Disadvantages: Measures clot properties only, insensitive to aspirin
Thromboelastography (TEG)
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: High shear platelet function
Advantages: Simple
Disadvantages: Requires blood counter
Glass filterometer
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: In vivo platelet activation markers
Advantages: SImple, systemic measure of platelet activation
Disadvantages: Prone to artefact
Platelet release markers (e.g BTG PF4)
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Global haemostasis. High shear platelet function.
Advantages: Measures global haemostatic function
Disadvantages: Cost of cartridges
Clot signature analyser (CSA)
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: High shear platelet adhesion/aggregation
Advantages: Small volume of blood, physiological
Disadvantages: Little widespread experience
Cone and plate(let) analyser (CPA) or IMPACT device
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Platelet glycoproteins, activation markers, platelet function
Advantages: Whole blood test, flexible, wide variety of tests
Disadvantages: Specialised operator expensive equipment
Flow Cytometry
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Platelet counting pre and post activation
Advantages: Simple point of care instruments
Disadvantages: indirect test measuring count after aggregation
Ichor - plateletworks
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Platelet contractile force, clot clastic modulus and thrombin generation time
Advantages: Rapid and simple
Disadvantages: Measure mainly clot properties
Hemostasis analysis system
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Platelet procoagulant activity
Advantages: Simple
Disadvantages: Insensitive to aspirin and Gp Ib function
Hemostasus Device
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Platelet micro-aggregates
Advantages: Sensitive, study hyperfunction
Disadvantages: Little wideaspread experience
Laser platelet aggregometer (PA-200)
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: High shear adhesion/aggregation
Advantages: Rapid and simple screening, In vitro bleeding time, potential point of care instrument
Disadvantages: Inflexible
Platelet function analyser (PFA-100)
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Efficacy of anti-platelet therapy e.g Gp IIb/IIIa, aspirin, clopidogret
Advantages: Simple test point of care instrument
Disadvantages: Inflexible, cannot be used to detect platelet defects or VWD
Ultegra (RPFA) -rapid platelet function analyser
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: High shear platelet function
Advantages: Simple
Disadvantages: Little widespread experience
Thrombotic status analyser (TSA)
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: High shear platelet function and global haemostasis
Advantages: Simple
Disadvantages: Little widespread experience
Gorog Thrombosis Test
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Platelet adhesion to a collagen membrane with a cut
Advantages: Simple
Disadvantages: Prototype
Platelet-Stat
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: Potentially measures total protein content
Advantages: Increasing sensitivity
Disadvantages: Normal proteome yet to be fully defines, loss of some membrane proteins during analysis. Requires pure preparations,
Sensitive proteomic analysis
WHAT PLATELET FUNCTION TEST IS..
Aspects of platelet function test: measures total mRNA content by microarray technology
Advantages: Potentially measures message from all MK/platelet synthesized proteins
Disadvantages: Platelet genome yet to be fully defined. Required pure preparation. Instability of mRNA preparations.
Platelet Genome Analysis
