Immunohaematology

What is von Willebrand's factor?

• Phospholipid required for lysing clots

• Plasma membrane glycoprotein that attaches platelets to injured sub endothelium

• A coagulation inhibitor

• A coagulation factor also known as factor I

Which of the following would be incompatible in a crossmatch?

• A Rh negative donor and A Rh negative recipient

• O Rh positive donor and A Rh positive recipient

• AB Rh positive donor and A Rh positive recipient

• A Rh positive donor and A Rh negative recipient.

What is the most likely reason for the following discrepancy?

• A patient with an acquired B antigen due to infection with a Gram-negative bacteria

• A newborn

• A patient with multiple myeloma

• An individual with a subgroup A

Fibrinolysis can be defined as which of the following:

• Construction of blood vessels

• The formation of a fibrin clot

• The breakdown of fibrin within the blood clots

• The aggregation of platelets at the site of injury

A 3-year-old boy with sudden severe bleeding problems has the following results:

PT = normal. aPTT = prolonged

Platelet count is normal. aPTT is normal with mixing studies

These clinical manifestations and laboratory results are consistent with:

• Aspirin

• Heparin

• Vasodilation

• A factor deficiency

This anticoagulant works by competing with vitamin K

• Aspirin

• Factor VIII

• EDTA

• Warfarin

Aspirin helps to prevent thrombosis by:

• Preventing carboxylation needed for clotting factors

• Inhibiting serine protease

• Preventing platelet adhesion

• Preventing the function of cyclo-oxygenase

A deficiency of which factor may result in Hemophilia A?

• Factor VIII

• Factor I

• Facto X

• Factor III

What is the specimen of choice for routine coagulation testing?

• Heparin

• Sodium Fluoride

• Sodium Citrate

• EDTA

Platelets first come in contact with exposed sub-endothelium during:

• Aggregation

• Adhesion

• Secretion

• Vasoconstriction