Platelet disorders Flashcards
What is ITP?
immune thrombocytopenic purpura
autoimmune, ab against GP2b3a
spleen destroys the platelet-antibody complexes
increase in megakaryocytic in the bone marrow
thrombocytopenia and increased bleeding time
**commonly due to a viral illness
What is the treatment for ITP?
steroids
IVIG
splenectomy b/c 1/3 of platelets are sequestered in the spleen
What is TTP?
ADAMTS13 vWF metalloprotease deficiency. Can’t degrade the vWF multimers
thrombotic thrombocytopenic purpura
excess platelet activation and thrombosis.
consumptive thrombocytopenia
increased bleeding time, get purpura
What types of labs do you see with TTP?
schistocytes: moving pass thrombosis, get sheared. Called microangiopathic hemolytic anemia
increased LDH
What are the symptoms seen in HUS v. TTP?
HUS more mild, kidney-centered triad: hemolysis uremia thrombocytopenia
TTP more severe, neuro involvement HUNT For The Toilet Paper Hemolysis Uremia Neuro symptoms thrombocytopenia fever TTP
What is the treatment for TTP?
plasmaphoresis
steroids
What are some other causes of thrombocytopenia?
heparin-induced thrombocytopenia aplastic anemia (pancytopenia)
What’s the deal with bernard soulier syndrome?
defect of GP1b on platelets. Can’t adhere.
get very little thrombocytopenia, but DO get increased bleeding time
What’s the deal with Glanzmann thrombasthenia?
defect in GP2b3a
can’t have platelet aggregation
normal platelet count, but increased bleeding time
What is the most common inherited bleeding disorder? How is it inherited?
Von Willebrand Disease
Aut dom
What’s the deal with vWF disease?
decreased vWF
causes intrinsic pathway problem b/c not there to stabilize factor 8a, increased PTT
causes platelet adhesion problem b/c not there to bind GP1b, increased bleeding time
no thrombocytopenia, or increase in PT
What is the treatment of vWF disease?
ADH (desmopressin) given to increase release of vWF from endothelial cells
What’s the deal with DIC?
disseminated intravascular coagulation get thrombosis everywhere!! get thrombocytopenia as a result. get increased bleeding time. deficiency of clotting factors by consumption-->increased PT and PTT risk of multi organ failure
What do you see on labs w/ DIC?
decreased fibrinogen
decreased factors 8 & 5
schistocytes
D-dimers
What are some causes of DIC?
STOP Making New Thrombi Sepsis (gram neg) Trauma OB Pancreatitis (acute) Malignancy Nephrotic syndrome Transfusion
