Author Question: A patient's blood film shows a moderate number of spherocytes and polychromasia. Select the best ... (Read 120 times)

james9437 · **on:** Jun 25, 2018

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 2

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.

bbburns21 · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

ANS: A
The only one of these tests that distinguishes warm autoimmune hemolytic anemia from hereditary spherocytosis is the direct antiglobulin test that is positive in warm autoimmune hemolytic anemia and negative in hereditary spherocytosis.

Answer to Question 2

ANS: B
Cold-reactive autoimmune hemolytic anemia caused is sometimes secondary 2 3 weeks after infections such as M. pneumoniae and infectious mononucleosis.