Hema 4 Part 2 - THROMBOCYTOPENIA Flashcards
(52 cards)
What is the definition of Thrombocytopenia?
Decreased platelet count below 100 x 10^9/L
Thrombocytopenia can lead to increased bleeding risk.
What is the definition of Thrombocytosis?
Increased platelet count of more than 450 x 10^9/L
Thrombocytosis can be reactive or due to myeloproliferative disorders.
Define Thrombocythemia.
Fixed increase in circulating platelets associated with myeloproliferative disease
Thrombocythemia is often seen in conditions like essential thrombocythemia.
What characterizes Thrombasthenia?
Functionally abnormal platelets (no fibrinogen receptors); normal count
Thrombasthenia can lead to bleeding disorders despite normal platelet numbers.
What is Thrombocytopathia?
Functionally abnormal platelets due to defective platelet factor 3
Thrombocytopathia can result in impaired platelet function despite a normal platelet count.
What is a common cause of Thrombocytopenia?
Impaired or decreased production
Causes can include bone marrow disorders or congenital conditions.
What is the normal platelet count range?
100 x 10^9/L to 440 x 10^9/L
Counts outside this range indicate thrombocytopenia or thrombocytosis.
Changes in platelet count may be observed in the following:
- lower in west indians & africans
- 20% higher in women
- 1st year of birth
- vigorous exercise
- epinephrine infusion
- smokers
- obese
- after childbirth
- alcohol intake
Q: At what platelet count do symptoms of thrombocytopenia typically appear?
A: Usually when the platelet count falls below 50 × 10⁹/L.
At what platelet count does the risk of severe and spontaneous bleeding significantly increase?
A: When the platelet count drops below 10 × 10⁹/L.
Q: What is the primary cause of thrombocytopenia due to decreased production?
A: Failure of the bone marrow to produce adequate amounts of platelets.
Q: What are the three main categories of inherited thrombocytopenia?
- Inherited thrombocytopenia with small platelets
- Inherited thrombocytopenia with normal
- Inherited thrombocytopenia with large/giant platelets
Name an inherited thrombocytopenia disorder with small platelets.
A: Wiskott-Aldrich syndrome.
WAX
What is Wiskott-Aldrich syndrome associated with?
A: Decreased platelet aggregation to ADP, epinephrine, and collagen, along with reduced T-cell number and function.
Name an inherited thrombocytopenia disorder with normal-sized platelets.
A: Fanconi anemia syndrome.
FATFQD
What is Thrombocytopenia with Absent Radius (TAR) syndrome?
A: A disorder characterized by absent radius bones in the forearm and thrombocytopenia.
Name an inherited thrombocytopenia disorder with large/giant platelets.
A: Bernard-Soulier syndrome.
What is the genetic mutation associated with inherited thrombocytopenia with large/giant platelets?
A: Mutation in the MYH9 gene.
Name three inherited thrombocytopenia disorders with large/giant platelets.
FEM
What is May-Hegglin anomaly?
A: A condition involving thrombocytopenia, giant platelets, and Döhle-like inclusions in neutrophils
Other than congenital in decreased production what are also listed?
Infection, radiation, drugs, ineffective thrombopoiesis, myelopthisis
What is the laboratory findings in terms of bleeding time and clot retraction
increased when platelet count is less than 100x109/L
Clot retraction is abnormal if plt is less than 60x109/L
Increased loss/ destruction includes
Nonimmune destruction
Immune Platelet Destruction
