RBC part 4 Flashcards
what is acute chest syndrome
dangerous microvascular occlusive crisis in lung
fever, cough, chest pain, and pulmonary infiltrates
acute chest syndrome is a complication of what
sickle cell anemia
gallstone formation is seen in what
sickle cell anemia
hereditary spherocytosis
sickle cell anemia is diagnoses how?
sickle cells on peripheral blood smear
sickling test
hemoglobin electrophoresis or HPLC
what is the sickling test
reducing agents like metabisulfate added to blood to induce sickling
what is HbC
a variant hemoglobin which lysine is substitutes for glutamic acid on beta goblin chain
what is HbSC
sickling disorder but less severe than people homozygous for the sickle gene
dehydration does what do sickling
increases MCHC promoting sickling
low pH and increase of temperature have what effect on sickling
promote it
what does hydroxyurea do in sickle cell patients
increases HbF
used as part of therapy
hereditary spherocytosis has what phylogenetic pattern
Autosomal dominant (common in northern europeans)
what is the issue in hereditary spherocytosis
mutation in ankyrin (RBC membrane skeleton protein)
weakened anchor for lipid bylayer
a weakened anchor for lipid bilayer is seen in what
hereditary spherocytosis
hereditary spherocytosis presents clinically with what
jaundice, splenomegally hemolytic anemia gallstones anemic crisis fever
diagnosis for hereditary spherocytosis is done through what
osmotic fragility test
negative DAT test
reticulocytosis
what is the only notable disease with microcyosis and increased MCHC
hereditary spherocytosis
what is the result of osmotic fragility test in hereditary spherocytosis
increased osmotic fragility (right shift)
decreased osmotic fragility test is seen in what
thalassemia, iron deficiency anemia
how is hereditary spherocytosis treated
folic acid supplements
splenectomy (treatment of choice)- eliminates site of hemolysis
bite cells can be seen in what conditions
HbH
G6PD deficiency
G6pD deficiency is protective against what
falciparum malaria
what does G6PD normally do
gives red blood cells antioxidant protection- makes NADPH
without G6PD what happens to hemoglobin
it gets denatured
heinz bodies are seen in what conditions
G6PD
alpha thalassemia
G6PD produces what from what
NADPH from NAD (eventually reduces glutathione)
the mediterranean variant of G6PD deficiency results in what
severe decrease in G6PD
what clinical findings can be seen in G6PD deficiency
extravascular in spleen
hemolysis of stressed RBCs
intravascular by heinz bodies
what are some precipitating factors of G6PD deficiency
infections (hepatitis, typhoid, pneumonia)
oxidant drugs (antimalarials)
fava beans
what is the defect in self-limited acute attacks of G6PD deficiency
stability of enzyme (only older RBCs affected)
immune hemolytic anemias are based on what
antigen that stimulates antibody or complement-mediated RBC destruction
Autoimmune Hemolytic Anemias have what
autoantibodies to RBCs
Autoimmune Hemolytic Anemias are detected how
direct coombs test (DAT)
agglutination is a positive what test
coombs
increased osmotic fragility is seen in what conditions
hereditary spherocytosis
autoimmune hemolytic anemia
Warm Antibody Hemolytic Anemia is what and due to what
antibodies reactive to body temperatures
IgG autoantibodies
Warm Antibody Hemolytic Anemia what is going on
macrophage Fc receptors bind to protruding Fc ends of IgG antibodies
Warm Antibody Hemolytic Anemia drug-induces models that have been well studied are
methyldopa (L-dopa)- Rh blood group antibody
penicillin-hapten: antibody against drug
tetracylcines, cephalosproins, tolbutamide
what disorders are associated with Warm Antibody Hemolytic Anemia
lymphatic malignancies (CLL) autoimmune disorders (SLE, RA)
Cold Antibody Hemolytic Anemia is due to what
monoclonal IgMs induced at colder temperatures (room temperature can happen)
acute Cold Antibody Hemolytic Anemia is due to what
atypical pneumonia (agglutinins against I) infectious mononucleosis (agglutinins against i)
chronic Cold Antibody Hemolytic Anemia is due to whaat
lymphoid malignanct or idopathic
paroxysmal cold hemoglobinuria is due to what
IgG autoantibody (Donath-landsteiner antibody) that works via biphasic hemolysis
what is biphasic hemolysis and where is it seen
at low temperatures binds to cell without causing hemolysis then warming binds complement to it and intravascular hemolysis occurs
seen in paroxysmal cold hemoglobinuria
Donath-landsteiner antibody is seen in what and what kind of antibody
paroxysmal cold hemoglobinuria
IgG
how is paroxysmal cold hemoglobinuria diagnosed
test for Donath-landsteiner antibody by mixing patients serum with test RBCs, first chill then warm and see if lysis occurs
