intrinsic hemolysis Flashcards
(33 cards)
what is PNH ?
paroxysmal nocturnal hemoglobiunuria
the mechanism is increased complement driven destruction of RBCs caused by a deficiency in CD55/59 and deficiency of GPI anchor ( acquired PIGA genetic mutation in the stem cells )
what is the classic presentation associated with PNH ?
patient wakes up with red urine , classically causes hemolysis at night
iron defeciency is common
law extravascular hemolysis what is the coombs test result ?
always positive in extravascular hemolysis
what is the triad associated with PNH ?
Coombs test negative
pancytopenia
venous thrombosis budd chiari syndrome)
also associated with erectile dysfunction , dysphagia and abdominal pain
what are the diseases associated with PNH ?
aplastic anemia
acute leukemias
what is the treatment for PNH ?
eculizumab
what is the leading cause of death in PNH ?
thrombosis
how can we confirm the diagnosis of PNH ?
flow cytometry shows CD 55/59 negative
what is the mechanism of eculizumab ?
targets terminal compliment C5
what is pyruvate kinase deficiency ?
autosomal recessive disease associated with pyruvate kinase enzyme defeciency
there is a decrease in ATP production making the RBC more rigid causing extravascular hemolysis
levels of what intermediate is increased in pyruvate kinase defeciency ?
2,3 BPG
what is seen pn peripheral blood smear in pyruvate kinase deficiency ?
burr cells are also called echincocytes
why is there extravascular hemolysis in association with pyruvate kinase defeciency ?
the RBCs become so rigid and the membrane fails - phagocytosis in the spleen
what is the classic presentation associated with pyruvate kinase deficiency ?
hemolytic anemia in newborns
splenomegaly
what is G6PD ?
autosomal recessive diseases associated with a deficiency in G6PD
RBCs have a higher susceptibilty for oxidative stress
what are the triggers associated with G6PD ?
viral infections
dapsone
fava beans
primaquine
sulfa drugs
what type of hemolysis is associated with G6PD ?
both intravascular and extravascular hemolysis
what cells are seen on peripheral blood smear in G6PD ?
heinz bodies and bite cells
degmacytes are called bite cells
what intermediate is low in level when it comes to G6PD ?
NADPH - absence of it causes hemolysis due to decreased protection from oxidative stress
what can having G6PD protect against ?
malaria
what is the classic presentation associated with G6PD?
patient from africa
present with back pain
jaundice dark urine and anemia
often exposed to a trigger
what is the pathology of bite cells ?
associated with G6PD , where there is a bite taken out by splenic macrophages
how is a diagnosis of G6PD made ?
fluoroscent spot test - failure ,, must test outside of an acute attack
what is the mode of inheritance of hereditary spherocytosis?
autosomal dominant
