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52 Cards in this Set
- Front
- Back
Do RBCs contain more AST or ALT?
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AST (2-3:1)
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How high does bilirubin have to be to see sceral icterus
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2-3mg/dl
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Clinical picture of congenital spherocytosis
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hemolytic anemia, (early) gallstones, splenomegaly, jaundice
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Inheritance pattern of congenital spherocytosis
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2/3 autosomal dominant
1/3 spontaneous mutation |
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how do you calculate MCHC
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MCH/MCV
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What scenerios make interpretation of osmotic fragility test difficult?
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s/p transfusion (not patient's own cells)
high reticulocyte count young age - less than 6-12 months |
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What is the difference between the African and the Asian variants of hereditary elliptocytosis?
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African has mild hemolysis, Asian is more severe hemolysis.
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Name two X-linked inheritence RBC enzyme disorders
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G6PD Deficiency
Phosphoglycerate kinase (PGK) deficiency |
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What morphological finding is associated with pyruvate kinase deficiency?
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Ecchinocyte
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Pathophysiology of pyruvate kinase deficiency?
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decreased synthesis of ATP -> high 2,3DPG levels -> greater O2 release at low hemoglobin concentrations
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How does the type of hemolysis differ between pyruvate kinase deficiency and G6PD deficiency?
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Pyruvate kinase: extravasular
G6PD: intravascular |
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What can initiate a hemolytic reaction in a patient with G6PD?
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infections
sulfa drugs naphthalene antimalarial drugs |
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When should you test for G6PD?
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After the resolution of a acute event.
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What morphologic finding is associated with pyrimidine 5'-nucleotidase deficiency?
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basophilic stippling
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What is basophilic stippling?
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precipitated (condensed) ribosomal protein (RNA)
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When is basophilic stippling seen?
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lead poisoning
severe bacterial infection drug exposure alcoholism anemias with impaired hemoglobin synthesis megaloblastic anemia refractory anemia. |
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What is a Heinz body?
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a cellular inclusion in a RBC that consists of damaged (unstable/denatured) aggregated hemoglobin,
associated with some forms of hemolytic anemia |
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What infection are patients with congenital hemolytic anemia at greater risk for?
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Parvo B19 infection
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Interventions for patients with congenital hemolytic anemia
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Folate supplementation
RBC transfusions splenectomy |
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What are the two types of inherited hemolytic disorders
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RBC membrane disorder
RBC enzyme disorder |
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What is the mode of inheritance for RBC membrane disorders? for enzyme disorders?
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membrane: AD
enzyme: AR |
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What are the results of osmotic fragility tests in RBC membrane disorders? in RBC enzyme disorders?
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membrane: abnormal
enzyme: normal |
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what are the results of autohemolysis test with RBC membrane disorder? with RBC enzyme disorder?
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membrane: corrects with glucose
enzyme: no correction |
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What is the response to splenectomy in RBC membrane disease? in RBC enzyme disease?
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membrane: complete response
enzyme: parital response |
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What are the three types of hemolytic anemia caused by erythrocyte autoantibodies?
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Warm Reactive IgG antibodies
Cold Reactive IgG antibodies (Paroxysmal Cold Hemoglobinuria) Cold agglutinin disease |
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What type of antibody mediates:
- Warm AIHA - PCH - Cold agglutinin disease |
Warm: IgG +/- complement
PCH: IgG + complement Cold: IgM + complement |
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What are warm and cold antibodies?
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Warm antibodies are immunoglobulins that bind to erythrocyte membrane antigens at 37 degrees, they rarely fix complement. They are ususally IgG.
Cold antibodies optimally bind to erythrocyte membrane antigens at 4 degrees, they usually fix complement and they are usually IgM. |
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What is the Donath-Landsteiner antibody?
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An IgG autoantibody that is responsible for hemolysis seen in paroxysmal cold hemoglobinuria. Unlike most IgG it binds antigen at 4 degrees and it can fix complement.
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What does DAT stand for?
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Direct Antiglobulin test
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What can DAT detect?
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IgG or C3 bound to the RBC surface (using monoclonal antibodies against IgG or C3)
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Why test for C3 and not IgM?
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IgM isotypes typically efficiently bind complement
IgM antibodies tend to spontaneously dissociate from the RBC membrane and therefore might not be reliable |
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Is the hemolysis associated with AIHA intravascular or extravascular?
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Warm: ususally extravascular (IgG does not fix complement, instead it coats the RBC which is then destroyed in the spleen)
Cold: usually intravascular (b/c the IgM fixes complement) |
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What is the antigen specificity for:
warm AIHA PCH Cold AIHA |
warm: Rh and others (anti-U, anti-Kell, anti-Jka, Anti Fya)
PCH: P antigen Cold: I,i |
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What is the treatment for warm AIHA?
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steroids
splenectomy |
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What is the treatment for Paroxysmal Cold Hemoglobinuria (PCH)?
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avoid cold
steroids |
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What is the treatment for cold AIHA?
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avoid cold
plasmapheresis. |
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What are the lab findings in AIHA?
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anemia
elevated LDH elevated indirect bilirubin low haptoglobin |
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Do you see dark urine in warm or cold autoimmune hemolytic anemia?
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Cold b/c it is an intravascular hemolysis
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What are the most common CNSHA (Congenital non-spherocytic hemolytic anemias)
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G6PD deficiency
Pyruvate kinase deficiency |
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What varient of G6PD deficiency is found in the mediteranean population? african?
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mediterranean: B- (more severe)
African: A- |
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pathophysiology of PNH (paroxysmal Nocturnal hemoglobinuria)
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defect in the formation of RBC surface protein anchor: GP1. Therefore surface proteins: CD 55, CD 59 are not able to be sufficiently anchored. B/c of this there is increased complement mediated cell death. -> anemia
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How do you test for PNH?
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Flow cytometry: absent or reduced CD 55 and CD 59 (b/c they cannot anchor to the RBC surface)
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When do you see Heinz bodies? What else would be abnormal on electropheresis?
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In the presense of unstable denatured hemoglobins. You would see other hemoglobins beside Hgb A.
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what causes the oxygen dissociation curve to shift to the left (decreased tissue delivery)
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fetal hemoglobin (binds less 2,3DPG)
methemoglobin alkalosis (increased pH) low temp |
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what is triose phosphate isomerase characterized by
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AD inheritance
hemolytic anemia neonatal hyperbilirubinemia progressive neurologic dysfunction increased susceptibility to infection cardiomyopathy |
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Match the disorders with the associated pathways
triose phosphate isomerase deficiency pyruvate kinase deficicency G6PD deficiency glycolytic pathway hexose monophosphate shunt Embden Myerhof pathway |
triose phosphate isomerase deficiency - Embden Myerhof pathway
pyruvate kinase deficiency - glycolytic pathwasy G6PD deficiency - hexose monophosphate shunt |
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in what conditions are Heinz bodies seen
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unstable hemoglobin (including HgB Koln, Zurich, Gamma)
G6PD deficiency Hemoglobin H |
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what are pappenheimer bodies
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degenerating cellular remnants which contian iron and are most likely related to accelerated red cell division or impaired hemoglobin synthesis
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when are pappenheimer bodies seen
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severe anemia
thalassemia s/p splenectomy |
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what MCHC would be very suggestive of spherocytosis
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MCHC > 36%
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what is the most common ABO set-up for hemolytic disease of the newborn
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O mom
A baby |
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why is plasmapheresis helpful in the treatment of TTP
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TTP is due to absence of vWF cleaving protease - either congenital or acquired (inhibitor)
plasmapheresis removes the inhibitor and replaces the missing protease (in FFP) |