Deck 26: Extrinsic Defects Leading to Increased Erythrocyte Destruction Immune Causes

Question 1

Which of the following is true regarding the mechanism of warm-reactive autoimmune hemolytic anemia?

A)Immunoglobulin G (IgG) autoantibodies cause intravascular hemolysis.
B)IgG autoantibodies cause extravascular hemolysis.
C)Immunoglobulin M (IgM) alloantibodies cause complement activation.
D)IgM autoantibodies cause immune complex formation.

Answer 1

IgG autoantibodies cause extravascular hemolysis.

Question 2

All of the following have been linked to excess erythrocyte destruction except

A)drugs.
B)IgM autoimmune antibodies.
C)immunoglobulin E (IgE) alloantibodies.
D)IgG alloantibodies.

Answer 2

immunoglobulin E (IgE) alloantibodies.

Question 3

Red cell agglutination is found on a blood film.Select the best course of action.

A)Report the morphology and all automated results.
B)Warm the blood, and rerun it though the automated cell counter.
C)Warm the blood, and make a new blood film.
D)Perform a cold agglutinin test.

Answer 3

Warm the blood, and rerun it though the automated cell counter.

Question 4

Which of the following is most often the result of human error?

A)erythroblastosis from anti-D
B)ABO erythroblastosis
C)delayed hemolytic transfusion reaction
D)immediate hemolytic transfusion reaction

Question 5

A type-A Rh-negative infant has spherocytes on his blood film and a weakly positive direct antiglobulin test.What antibody will most likely be found on the infant's red cells?

A)IgG anti-A antibody
B)IgM anti-A antibody
C)D antibody
D)Kell antibody

Question 6

A warm-reactive autoimmune hemolytic anemia found in combination with thrombocytopenia in a patient is called

A)Evans syndrome
B)Wiskott-Aldrich syndrome
C)hereditary spherocytosis with thrombocytopenia
D)paroxysmal cold hemoglobinuria

Question 7

Which of the following causes of alloimmune hemolytic anemia accounts for the largest number of deaths?

A)ABO blood type errors from patient misidentification
B)drug reactions to antibiotic agents
C)ABO hemolytic disease of the newborn
D)ABO blood type technical testing errors

Question 8

An Rh-negative woman is pregnant with her third child.She received little or no prenatal care during the first two pregnancies.Her anti-D titer is 1:512 at 30 weeks of gestation.What is the likely outcome for the baby?

A)ABO hemolytic disease of the newborn
B)Rh hemolytic disease of the newborn
C)no or mild hemolysis but spherocytes on the blood film
D)most likely not survive

Question 9

Secondary cold-reactive autoimmune hemolytic anemia is found most often in patients with

A)hemolytic disease of the newborn caused by anti-A or anti-D
B)acute myeloid leukemia and chronic myleogenous leukemia
C)Mycoplasma pneumoniae or infectious mononucleosis
D)hereditary spherocytosis or hereditary elliptocytosis

Question 10

A patient's blood film shows a moderate number of spherocytes and polychromasia.Select the best test to distinguish warm autoimmune hemolytic anemia from hereditary spherocytosis.

A)direct antiglobulin test
B)bilirubin test
C)haptoglobin test
D)reticulocyte count

Question 11

Monospecific anti-C3b/C3d reveals agglutination with patient's red cells.Monospecific IgG antisera gives a negative result.Which red cell morphology would most likely be observed?

A)spherocytes
B)schistocytes
C)acanthocytes
D)agglutination

Question 12

The Donath-Landsteiner antibody

A)binds to the red cell membrane at 37° C.
B)is found in serum and causes lysis of donor RBCs, which have first been incubated at 4° C and then warmed to 37° C.
C)has specificity for Ii blood group antigens.
D)is associated with lymphoma.