Platelet Function Disorders

Question 1

platelet function disorders can occur because of defects in the:

Answer 1

platelet membrane, receptors, or granules

Question 2

patients with function disorders exhibit the same symptoms as those with:

Answer 2

disorders of primary hemostasis (easy bruising, mucous membrane bleeding, and an increased risk of bleeding with trauma or invasive procedures)

Question 3

3 clinical settings of acquired platelet dysfunction

Answer 3

hematologic disease, systemic illness, or as a result of therapy.
-pts with myeloproliferative disorders and plasma cell disorders may exhibit abrormal platelet function.
- liver disease and significant renal disease can also be associated with platelet dysfunction since uncleared metabolic products may inhibit platelet function.
- asprin, NSADs, etc also cause platelet dysfunction.
NSAID also inhibits COX similarly, but the affect is revesible and only lasts for as long as the NSAID is in circulation.

Both contribute to artierial disrease and thrombosis.
• these drugs are used to prevent MIs and strokes

Question 4

examples of congenital disorders, and what is needed to diagnose them

Answer 4

Glanzmann’s Thrombasthenia (autosomal recessive disorder). Therefore, in the presence of normal plasma
levels of fibrinogen:
–  Aggregation of platelets to each other (prolonged
bleeding time/closure time)

• Bernard-Soulier syndrome is also autosomal recessive. Platelets lack membrane receptors (GP1b)
  for von Willebrand factor
• Gray Platelet Syndrome is caused by a lack of secretory proteins within the alpha granules. Platelets and megakaryocytes unable to synthesize contents of α-granules
  • Platelets are large and gray, lacking α-granule

need electron microscopy or flow cytometry to assess platelet surface markers and granule contents.