05 Platelet Disorders
Glanzman's
- superficial bleeding
- nl aggregation with ristocetin test
Bernard
- large platelets on smear
- abnormal ristocetin assay
Wiskott- Aldrich
Acquired
- ITP
- TTP
- HUS
- DIC
- Uremia
- thrombocytopenia
- vWF
- Hayde's
ITP
- don't live as long as they should = low number
- macrophages clear antibody bound platelets
- platelet thrombi: platelet low, coagulation factors not consumed
TTP
- much more dangerous
- low platelets, thrombosis
- thrombus form in small vessels, consumes platelets, thrombocytopenia
- TTP: build up of platelets and RBC, obstruction
- small vessel occlusion in CNS
- thrombi primarily made of platelets, do not consume clotting factor
- platelet thrombi: platelet low, coagulation factors not consumed
HUS
- distinguish from TTP: no fever or CNS symptoms (TTP only with kidney)
- platelet thrombi: platelet low, coagulation factors not consumed
DIC
- both platelets and fibrin, increased PT, PTT
- TF activate coagulation cascade
- sepsis: high levels of cytokines and endotoxins
- every blood test abnormal
- platelet thrombi: platelet low, coagulation factors not consumed
Uremia
- caused by toxins, not platelets
Thrombocytopenia
Von Willebrand
- heavy periods common early presentation
- ristocetin test normal in glanzman
- ristocetin test also abnormal in Bernard
Hayde's
- aortic stenosis: increased risks of angiodysplasia
- overactivity of ADAMST13, breaking down multimers, causing VWF to be less efficient
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