chapter 38 - quantitative disorders of platelets: thrombocytopenia & thrombocytosis

develop thrombi due to accumulation of high-molecular-weight vWF multimers

px with thrombotic thrombocytopenic purpura (TTP)

megakaryocyte hypoplasia

NOT a hallmark of acute immune thrombocytopenic purpura

• petechiae

• thrombocytopenia

• large overactive platelets

• megakaryocyte hypoplasia

HPA-1a

specific antigen most commonly responsible for development of neonatal alloimmune thrombocytopenia (NAIT) in white patients is

acute ITP

a 2 year old child

• unexpected platelet count — 15,000/uL

• recent history of a viral infection

px most likely has?

anagrelide

drug that causes reduction in platelet count by inhibiting megakaryocyte maturation

mucosal bleeding

platelet abnormalities often result in

the combination of the drug and the platelet membrane protein to which it is bound

when drug acts as a hapten to induce thrombocytopenia, an antibody forms against which of the following?

• typically unexposed new platelet antigens

• combination of drug & platelet membrane protein to which it is bound

• the drug alone in the plasma, but the immune complex then binds to platelet membrane

• the drug alone, but only when it is bound to the platelet membrane

rarely emits spontaneously

in contrast to acute ITP, the chronic form of the disease:

the mother has an immune antibody to her own platelets, which crosses the placenta & reacts with the infant’s platelet

neonatal immune thrombocytopenia occurs when

diarrhea caused by Shigella species

hemolytic uremic syndrome (HUS) in children is associated with

atypical HUS

treatment with an anticomplement agent such as eculizumab is first-line therapy for

primary thrombocytosis resulting from essential thrombocytemia is self-correcting

statement regarding thrombocytosis is NOT true

• thrombocytosis can be associated with hemorrhage and thrombosis

• affected px have platelet counts in excess of 450,000/uL

• primary thrombocytosis resulting from essential thrombocytemia is self-correcting

• thrombocytosis can be congenital or acquired