Hemolytic Anemia Flashcards
intravascular hemolysis
RBC ruptures in circulation
extravascular hemolysis
RBC rupture happens outside of circulation
most commonly in the spleen
How is heme degraded?
broken down in spleen to biliverdin and unconjugated bilirubin
*unconjugated bilirubin then goes to liver
haptoglobin in intra/extravascular hemolysis
intra: decreased because haptoglobin binds to free heme sites
extra: normal
LDH in intra/extravascular hemolysis
may be elevated in both
indirect bilirubin in intra/extravascular hemolysis
unconjugated bilirubin can be elevated in both
see more elevation in extravascular hemolysis
why does intravascular hemolysis not contributed to indirect bilirubin as much?
only small amounts of heme bound to haptoglobin will be recycled to bilirubin
Hepatosplenomegaly and lymphadenopathy indicate …
extravascular hemolysis
Urine dip for heme in intra/extravascular hemolysis
intra: positive for heme in urine
extra: no
urine dip for RBC in intra/extravascular hemolysis
usually negative in all hemolysis
DAT / direct coombs
indicates if hemolysis is immune-mediated or not
DAT vs. IAT
DAT tests immunoglobin or complement directly on RBC
IAT tests for red cell antibodies in patient’s serum
warm immune hemolytic anemia
+DAT
IgG mediated
most complete treatment is splenectomy
what can acute spherocytes indicate?
acute hemolytic anemia
not hereditary
hereditary spherocytosis vs. autoimmune anemia
look at DAT / coombs test
hereditary spherocytosis
spherocytes cannot traverse through spleen sinusoids in times of inflammation
RBCs are damaged in the spleen
leads to RBC breakdown / anemia
Inheritance pattern of G6PD def.
X-linked
Pathophysiology of G6PD Def.
pentose phosphate shunt cannot regenerate NADPH which is needed for formation of glutathionine
therefore, cannot overcome oxidative challenges
Is hereditary spherocytosis intra or extravascular?
extravascular
is autoimmune hemolysis intravascular or extravascular?
IgG = extravascular
IgM = intravascular
is G6PD def. intra or extravascular?
mostly intravascular
is sickle cell intra or extravascular?
both
is a-thalassemia intra or extravascular?
seems to be more extravascular
definitely intramedullary
what symptom is associated with elevated bilirubin?
jaundice