Pathologic activation / consumption of platelets due to antibodies against<unk> -platelet complex
Can be caused by unfractionated<unk>  or LMWH (10 times more common in unfranctionated)
Occurs in 0.5-5% of patients treated with<unk> 
Thrombosis occurs in 35-75% of patients ; 20-30% die within 1 month
HYPER-coagulable, despite low platelet count
activated platelets bound in clot, thus low platelet count
bleeding is unusual
activated platelets bound in clot, thus low platelet count
bleeding is unusual
Onset within 48h of initiating<unk> 
Drop in platelet count due to platelet activation by<unk> 
Platelet count usually normalizes in a few days with continued<unk>  treatment
Immune-mediated process
Onset typically 5-10 days after exposure to<unk> 
Complicated by thrombosis
Heparin-Induced Thrombocytopenia 
Marrow infiltration 
Disseminated intravascular coagulation
Viral infections 
Liver disease induced coagulopathy
Marrow suppression 
Vitamin K deficiency
Congenital thrombocytopenia