Bleeding Disorders Flashcards
What are the hereditary bleeding disorders we’re studying?
- Von Willebrand Disease
- Hemophilia A and B
- Hereditary platelet disorders
What are the acquired bleeding disorders we’re studying?
- DIC
- ITP
- TTP/HUS
What are the two types of bleeding?
- Platelet bleeding
2. Factor bleeding
What should you know about Platelet bleeding?
- Superficial (skin)
- Petechiae
- Patient doesn’t recall being hurt
- Spontaneous
What should you know about Factor bleeding?
- Deep (joints)
- Big bleeds
- Trauma
- Patient recalls incident when they were hurt
What are Petechiae?
Little red dots on surface of skin
-Symptoms you should think about with platelet bleeding
What symptom should you think about with platelet bleeding?
Petechiae
What is purpura?
Coalescence of petechiae into a large, red area
What MUST you know about Von Willebrand Disease?
- Most common hereditary bleeding disorder (almost 1/100)
- Autosomal dominant
- vW factor decreased (or abnormal)
- Variable severity
What’s Von Willebrand factor?
- Huge multimeric protein
- Made by megs and endothelial cells
- Glues platelets to endothelium
- Carries factor VIII
- Decreased or abnormal in vW disease
What are the 3 types of Von Willebrand Disease (EXAM!!)?
Type I (70%) - Decreased vWF Type II (25%) - Many subtypes, abnormal vWF but right amount Type III (5%) - No vWF
What does Factor VIII (carried by vWF) do?
Factor VIII - acts on IX to accelerate coagulation through intrinsic pathway
What are the symptoms of Von Willebrand Disease?
- Mucosal bleeding in most patients
- Deep joint bleeding in severe cases
- Common symptom for woman is very heavy periods
- Nosebleeds, easy bruising
What are the Lab Test results for vWD?
- Bleeding time: prolonged
- PTT: prolonged (“corrects” with mixing study)
- INR: normal
- vWF level decreased (normal in type 2)
- Platelet aggregation studies abnormal
What platelet membrane protein binds vWF?
GP Ib
What is Ristocetin? How does it interact with vWF?
Ristocetin is a platelet aggregator. It works by stimulating platelets to express glycoprotein Ib factors. It normally makes platelets aggregate. If you don’t have any vWF to bind GP Ib Ristocetin is not going to cause platelet aggregation.
How do you treat Von Willebrand Disease?
- DDAVP (raises VIII and vWF levels)
- Cryoprecipitate (contains vWF and VIII)
- Factor VIII (this is the main problem in most cases - works for Type I but not very good for Type III)
How does Hemophilia A & B relate to royalty?
Queen had spontaneous mutation an passed that gene down to her children. Then her children married into the royal families and there were a lot of problems (usually hemophilia is an X-linked recessive disorder but in this case it was a mutation)
How do mothers pass down the hemophilia genes?
X-linked
- Daughters become carriers
- Sons are affected
How does an affected father pass down hemophilia genes?
He will only make his daughters carriers. It will not affect his sons, but most of these conditions only manifest in males.
What things MUST you know about Hemophilia A?
- Most common factor deficiency
- X-linked recessive in most cases (30% are random mutations)
- Factor VIII level decreased
- Variable amount of “factor” bleeding
What should you know about Hemophilia A and B?
- Overall very uncommon
- Most common factor diseases
What are the symptoms of Hemophilia A?
- Severity depends on amount of VIII
- Typical “factor” bleeding
- –Deep joint bleeding
- –Prolonged bleeding after dental work
- Rarely, mucosal hemorrhage
- Can have hemophilic arthropathy of the knee/joint deformity
What are the Lab Test results in Hemophilia A?
- INR, TT, platelet count, bleeding time: normal
- PTT: prolonged (“corrects” with mixing study)
- Factor VIII assays: abnormal
- DNA studies: abnormal
What is the treatment for Hemophilia A?
- DDAVP (Desmopressin)
- Factor VIII
- Patients will continually need more and more Factor VIII (you save this for when they really need it and don’t give on a routine basis)
What things MUST you know about Hemophilia B?
- Factor IX level decreased (intrinsic pathway)
- Much less common than hemophilia A
- Same inheritance pattern
- Same clinical and laboratory findings
What should you know about Other Factor Deficiencies?
- These are rare
- XI deficiency: bleeding only after trauma
- XIII deficiency: severe neonatal bleeding
What pathway does Hemophilia A affect?
Intrinsic pathway - affects Factor VIII
What are the four hereditary platelet disorders?
- Bernard-Soulier Syndrome
- Glanzmann Thrombasthenia
- Gray Platelet Syndrome
- Alpha Granule Deficiency
What is Bernard-Soulier Syndrome known for?
- Abnormal Ib (binds platelets to subendothelium, binds vWF)
- Abnormal adhesion
- Big platelets - look fuzzy, large, about size of RBC
- Severe bleeding - can’t adhere their platelets into the sub endothelium
What is Glanzmann Thrombasthenia known for?
- No IIb-IIIa
- No aggregation
- Severe bleeding