Hemolytic Anemia Flashcards
PNH is predominantly extravascular or intravascular hemolysis? What about hereditary spherocytosis?
PNH = intravascular HS= extra
high LDH and low haptoglobin can be normal in ______hemolysis
can be normal or abnormal in extravascular hemolysis
what are intrinsic vs extrinsic abnormalities of RBC?
intrinsic: abnormalities in Hb structure or function, RBC membrane, or RBC metabolism (usually inherited problems); examples: G6PD, pyruvate kinase deficiency, hereditary elliptocytosis and dehydrating hereditary stomatocytosis
extrinsic: infection, RBC directed Ab, disordered vasculatrure
freebie info card
defective RBC are destroyed in the circulation or the spleen if they can’t deform and reform.
what causes hereditary spherocytosis
defects in “vertical” interaction (between cytoskeleton and lipid bilayer) which include AD mutations in ankyrin (ANK1), band 3 (SLC4A1) and B spectrin (SBTB) or AR defects in ANK1, alpha spectrin and EPB42
varying degrees of spectrin loss (major protein of cytoskeleton) which lead to spherocytosis and also weak cytoskeleton
presence of hemoglobunuria or hemosiderinuria suggests ____ hemolysis
intravascular
pigmented gallstones early on in life is a clue for
hereditary spherocytosis
clinical course HS
can be mild and asymptomatic, mild refractory anemia, or have crises
can have chronic iron overload even if non-transfusion dependent
splenomegaly
babies can present with neonatal jaundice and need preemptive phototherapy
diagnosis and lab clue for HS
can have normal MCV but higher MCHC due to dehydration
MUST get a DAT to rule out auto-immune and drug induced hemolysis
osmotic fragility test! (if unclear, can do EMA binding assay and then cryohemolysis where the sample is incubated at 27 for 24 hours)
NGS for gene mutations
HS Treatment
folic acid
splenectomy (after five years old) if symptomatic
What is DHSt and what causes it?
dehydrated hereditary stomatocytosis: normally when RBC goes through capillary/shear stress, RBC activates PIEZO1 which allows calcium influx and activated KCNN4 and K+ channels, drawing water out of the cell to make it smaller. Mutations in PIEZ01 leads to constitutive active channels
treatment of DGSt
NO splenectomy bc of increased risk of thrombus. supportive!
What is MAHA
microangiopathic hemolytic anemia is when microvascular or endothelial injury is present; coombs negative intravascular hemolysis (NOT Immune)
what is TMA
TMA is a type of MAHA when thrombosis or microthrombi are present
what are types of TMA
TTP, HUS (shiga toxin-TMA), aHUS(Complement mediated-TMA)
