Hemolysis Information Flashcards
is a patient always anemic with a hemolytic disorder?
no…marrow compensation can make up for the loss of RBCs
list 5 clinical features of hemolytic anemias
jaundice, dark urine, pigmented gallstones, chronic ankle ulcers, splenomegaly
parvovirus B19 affect on RBC production?
for about a week the virus will shut down RBC production in bone marrow….for normal individual this is okay but for sickle cell patient this is not
scleral icterus
yellowing of sclera in eyes
what 3 organisms do you vaccinate against prior to splenectomy?
haemophilus B, meningitis, pneumococcus
blood smear findings after splenectomy?
howelljolly bodies…small DNA remnants
if these are gone…then spleen may be coming back
aplastic crisis
reticulocyte and hemoglobin concentrations can plummit due to marrow being turned off for 7 days from the non encapsulated parvovirus B19
does parvovirus have a capsid or envelope?
NOOOOOOO..will not respond to solvents against membrane of viruses
extravascular hemolysis
macrophages in spleen and liver and marrow remove damaged or antibody coated RBCs
intravascular hemolysis
RBCs rupture within the vasculature
three modes of evidence for RBC production
elevated reticulocyte count
erythroid hyperplasia
deformation of long bones and skull
erythroid hyperplasia definition
more RBC precursors and way less myeloid precursors
usually more myeloid precursors but now more erythroid
two main pieces of evidence showing hemolysis
elevated LDH levels from increase in lysis
elevated bilirubin levels
why is LDH elevated in hemolytic issues?
LDH is a biproduct of lysis of cells
what type of bilirubin is elevated in hemolysis?
unconjugated…normally the liver is able to conjugate bilirubin but in case of hemolysis the liver is overwhelmed and we see more unconjugated bilirubin
When does reduced serum haptoglobin occur?
when hemolysis is occurring intravascularly
Why is haptoglobin lowered in intravascular hemolysis?
haptoglobin is made in liver and has longer half life…but when hemoglobin is available to bind the half life is shortened to minutes and leads to huge decrease
What is the problem with measuring hemoglobin A1C in a patient with high blood sugar and hemolytic anemia?
hemoglobin molecules dont hang around long enough to become glycosylated…so A1C will be falsely low!
hereditary spherocytosis mode of inheritance
autosomal dominant
hereditary spherocytosis problem
defect in a membrane protein and the lipid bilayer doesnt get tacked down outside of the RBC…the lipid microvesicles are then pinched off in the spleen
can have issue with parvovirus B19
what is common molecule leading to hereditary spherocytosis?
ankyrinin
CBC sign for hereditary spherocytosis
MCHC is elevated…only disease this changes
main mode of diagnosis of hereditary spherocytosis
eosin-5maleimide flow cytometry staining…when staining drops it is indicative of the disorder
osmotic fragility
a test for hereditary spherocytosis that is not done anymore…lysis occurs at higher tonicities
treatment for hereditary spherocytosis
folate supplement and splenectomy
importance of glucose 6 phosphate and G6PD enzyme for RBCs?
these molecules are part of the pentose pathway shunt in aerobic metabolism and help detoxify metabolites of oxidative stress….they protect RBCs from oxidative damage
what happens if you have low G6PD?
the oxidizing agents can act on hemoglobin and will lead to methemoglobin..denaturing the Hb
What is seen on smear with low G6PD?
heinz bodies lead to bite cells form macros biting off part off the heinz body from the RBCs
mode of inheritance of G6PD deficiency?
X linked, common in african americans, mediterranean variant is more severe with baseline levels
things to avoid if have G6PD deficiency?
fava beans, sulfa drugs like bactrim and septra, anti malarials, vitamin K, dapsone, mothballs
what to expect following a hemolytic episode from deficient G6PD?
G6PD levels in african americans may be normal since mature cells were lysed and young cells with regular G6PD will be left
in mediterranean since have baseline levels of deficiency you will see immediately following hemolytci episode
warm antibody autoimmune hemolytic anemia…antibody type and agglutination or not?
mediated by IgG antibodies…do not lead to agglutination
cold antibody autoimmune hemolytic anemia…antibody type and agglutination or not?
mediated by IgM and does lead to agglutination
what test to do for warm autoimmune hemolytic anemias?
direct coombs test
How does a direct coombs test work?
a patients RBCs will either be coated with antibodies or C3 from complement…coombs test has IgG antibodies for both of these that will bind them and then lead to clumping seen in test tube…must follow with specific test to see if it is IgG antibody or complement bound to the RBCz
process of disease in warm autoimmune hemolytic anemia?
the IgGs coat the RBCs, with or without C3…they then signal macrophages to eat because of macros binding the Fc receptor of the IgG…leads to spherocytes in blood
how to acquire warm antibody hemolytic anemia?
drugs…other autoimmune diseases like lupus…malignancy
clinical features of warm antibody hemolytic anemia?
splenomegaly, can have severe anemia, jaundice, positive coombs test and spherocytes
warm antibody hemolytic anemia treatments
corticosteroids first then splenectomy or rituximab if steroids dont work
process of disease in cold antibody hemolytic anemia
IgM will bind RBCs in extremities and then fix complement…as RBCs move to internal organs the IgMs fall off but complement still fixed…complement can then signal for direct lysis in blood or go to liver for macrophage to destroy
so have both intravascular and extrvascular hemolysis
IgM agglutination in cold antibody hemolytic anemia can lead to what?
cyanosis and ischemia in extremities because blockage by agglutination
two common causes of IgM mediated cold antibody hemolytic anemia?
infection with mycoplasma or mononuclesosis
lymphoproliferative disease called Waldenstroms macroglobulinemia
treatment for cold antibody hemolytic anemia
steroids and splenectomy do not work
keep patient warm and may need rituximab
microangiopathic hemolytic anemia mechanism and marker in smear
shear damage to RBCs as a result of endothelial cell activation
schistocytes in smear
microangiopathic hemolytic anemia cause
TTP/HUS and DIC
