PLATELETS: QUANTITATIVE ABNORMALITIES Flashcards
Normal platelet count
150 -400 x10^9/L
Thrombocytopenia
50- 100 x 10^9 /L
Spontaneous hemorrhage
20 x 10^9 /L
Life-threatening hemorrhage
< 10 x 10^9 /L
- Childhood and adult ITP
- Caused by an auto-Ab to the patient’s platelets.
- Most common disorder causing severe isolated thrombocytopenia.
- Treatment: Splenectomy , Corticosteroid (Prednisone) and IVIG.
Idiopathic thrombocytopenic purpura
caused by an alloantibody to HPA-1a
Dx- Complement Fixation, ELISA Tx- Plasmapheresis
Post-transfusion purpura (PTP)
fetal-maternal incompatibility of platelet antigens, and destruction of fetal platelets by a transplacental transfer of maternal antibody.
Fetal/ neonatal alloimmune thrombocytopenia
- The drug appears to be a hapten in which antibody binds to it and will attach to the platelets.
- The binding results to platelet injury and splenic sequestration and removal of platelet which causes the thrombocytopenia.
Drug-Induced Immune thrombocytopenia (DIIT)
recognized as the most common cause of DIIT.
Quinine
develops secondary to antibody produced to Platelet factor 4- Heparin complex.
Heparin- Induced thrombocytopenia and thrombosis (HITT)
Involves with ADAMTS 13 gene
Thrombotic thrombocytopenic purpura (TTP)
An umbrella term for “taking away” a blood component. From Roman aphairesis meaning to take away by force.
Apheresis
A general term used to denote the automated, selective removal of plasma. Plasmapheresis uses centrifugation to
separate the blood components, in contrast to dialysis, which uses filtration to separate small molecules from the blood.
Plasmapheresis
(also called therapeutic plasma exchange [TPE]) Removal of patient plasma and replacement with another fluid (eg,
donor plasma, colloid, crystalloid)
Plasma exchange
Thrombocytopenia may occur in pregnancy owing to coincidental development of the disorders mentioned earlier or due to the pregnancy itself.
Pregnancy-associated thrombocytopenia
