Deck 19: Hemolytic Anemia: Immune Anemias

Question 1

A patient with systemic lupus erythematosus (SLE) shows evidence of decreased hemoglobin and ongoing hemolysis. The DAT is negative. Which of the following is the most likely explanation for these results?

A) The subclass of IgG is not recognized by the polyspecific AHG.
B) The thermal amplitude of the antibody is <37°C.
C) High-dose IVIG used in treatment is interfering with the binding of AHG.
D) There is insufficient IgG for detection.

Answer 1

There is insufficient IgG for detection.

Question 2

A patient's hemoglobin went from a value of 13.0 gm/dl after transfusion to 10.6 gm/dl 3 days after transfusion. What is the most likely type of transfusion reaction?

A) Allergic
B) TRALI
C) HLA-mediated
D) Delayed

Answer 2

Delayed

Question 3

Cold autoimmune hemolytic anemia is usually caused by the presence of an:

A) IgD antibody
B) IgG antibody
C) IgM antibody
D) IgG1 antibody

Answer 3

IgM antibody

Question 4

Which of the following conditions is not paired with the correct autoantibody?

A) Infectious mononucleosis / autoanti-i
B) WAIHA / autoanti-K
C) CAD / autoanti-I
D) PCH / autoanti-P

Question 5

During transfusion, a patient developed pain in the area of the needle, shortness of breath, and chest tightness. What is the most likely cause?

A) Heart attack
B) Acute hemolytic transfusion reaction
C) TRALI
D) Anaphylactic transfusion reaction

Question 6

A 44-year-old female presents for her routine examination. She complains of tiredness and difficulty in breathing when she exerts herself. Her DAT is positive with polyspecific AHG and anti-IgG. Her hemoglobin is 7.5 gm/dl, and her indices suggest a normocytic, normochromic anemia. Her peripheral blood smear shows the presence of spherocytes. What is the most likely diagnosis?

A) CAD
B) Drug-induced IHA
C) WAIHA
D) Mixed-type AIHA

Question 7

A sample demonstrates a DAT profile that is positive with polyspecific AHG, negative with anti-IgG, and positive with anti-C3. If the Donath-Landsteiner test was also positive, what should the clinical laboratory professional do?

A) Perform an elution and antibody panel
B) Confer with the supervisor regarding the possibility of PCH
C) Request a serum sample for antibody screen
D) Perform a cold agglutinin test

Question 8

2 to 14 days after a transfusion, a patient is cross-matched for another transfusion. Slight hemolysis and a positive DAT are found. What testing should follow?

A) Urine hemoglobin
B) Elution procedure
C) Plasma-free hemoglobin test
D) Bilirubin measurement

Question 9

Which of the following antibody specificities is associated with PCH?

A) Anti-I
B) Anti-Le^a
C) Anti-P
D) Anti-D

Question 10

A patient is admitted with chest pain and extreme shortness of breath. Patient history is unremarkable except for ingestion of oral cefoxitin for the past 4 days. A DAT profile is positive with polyspecific AHG, negative with anti-IgG, and positive with anti-C3. The hemoglobin is 8.0 gm/dl. Based on these results, what mechanism of drug-induced hemolysis is present?

A) Immune complex
B) Autoantibody
C) Drug adsorption
D) Membrane modification

Question 11

The absence of spherocytes on the peripheral blood smear in a case of suspected HDFN usually indicates that which of the following is the most likely cause of the condition?

A) ABO HDFN
B) Splenic hypertrophy
C) Rh HDFN
D) HDFN from other blood group antibodies

Question 12

All of the following are consistent with a diagnosis of CAD except?

A) False increase in MCHC
B) DAT positive with polyspecific AHG and anti-IgG
C) Reticulocytosis
D) Increased total and unconjugated bilirubin

Question 13

Which of the following has the greatest effect on the rate of hemolysis in immune hemolytic anemia?

A) Presence of IgG2 on the erythrocyte
B) Limited number of antigens
C) Antibody that reacts at 37°C
D) Presence of IgM antibody

Question 14

Which of the following set of results is consistent with a diagnosis of WAIHA? Polyspecific AHG Anti-IgG Anti-C3

A) Positive Positive Negative
B) Positive Negative Negative
C) Negative Positive Positive
D) Positive Negative Positive

Question 15

Which of the following pairs of mother and fetus shows the most likely potential for initiating HDFN in the fetus? Mother Fetus

A) Group A, Rh positive Group O, Rh positive
B) Group B, Rh negative Group O, Rh positive
C) Group AB, Rh positive Group A, Rh negative
D) Group A, Rh negative Group AB, Rh negative

Question 16

Paroxysmal cold hemoglobinuria is associated with viral and bacterial infections in children. With what other disease(s) is it associated?

A) Lymphoproliferative diseases in adults
B) Mixed-type AIHA
C) CAD
D) Warm autoimmune hemolytic anemia

Question 17

Which of the following characterizes acute hemolytic transfusion reaction?

A) Extravascular hemolysis
B) Gastrointestinal hemorrhage
C) Intravascular hemolysis
D) Thrombosis

Question 18

Autoantibodies associated with CAD are directed against which antigen system?

A) ABO
B) I
C) Rh
D) P

Question 19

What test can demonstrate the presence of alloantibody?

A) Antibody screen
B) Agglutination in saline
C) Direct antiglobulin test
D) Indirect antiglobulin test

Question 20

Which of the following is an example of an anemia that occurs as a result of antibody development to an antigen that the individual lacks?

A) Autoimmune hemolytic anemia
B) Mixed-type autoimmune hemolytic anemia
C) Drug-induced hemolysis
D) Hemolytic disease of the newborn

Question 21

A patient on α-methyldopa could develop a type of drug-induced immune hemolysis that mimics what condition?

A) WAIHA
B) PCH
C) Immediate transfusion reaction
D) Delayed transfusion reaction

Question 22

Compare cold hemolytic anemias to WAIHA by immunoglobin class, optimal reactivity temperature, and mechanism of hemolysis:

Question 23

Explain why the DAT profile in CAD is reactive only with polyspecific AHG and anti-C3 but not with anti-IgG.

Question 24

A patient presents with anemia and spherocytes on the peripheral smear. How would you differentiate between hereditary spherocytosis (HS) and WAIHA?

Question 25

The most likely cause of immediate hemolytic transfusion reaction is from antibodies of which system?

A) Kidd
B) Rh
C) ABO
D) I

Question 26

Compare the three mechanisms of drug-induced immune hemolysis.

Question 27

ABO incompatibility is associated with which type of transfusion reaction?

A) Acute
B) Delayed
C) TRALI
D) Anaphylactic

Question 28

Paroxysmal cold hemoglobinuria is confirmed by a positive:

A) Antibody class IgM
B) Thermal amplitude of antibody over 20°C
C) Donath-Landsteiner test
D) Cold agglutinin test

Question 29

A newborn is left at a hospital emergency department. The baby appears lethargic and slightly jaundiced. Laboratory work on the baby shows a positive DAT with polyspecific AHG and anti-IgG. The hemoglobin is 7.3 gm/dl, and the peripheral blood smear shows marked polychromasia, macrocytosis, and an increased number of nucleated RBCs. The bilirubin is 4.4 mg/dl. What do you suspect is the underlying cause of these results?

A) ABO HDFN
B) Autoantibody from the mother in baby's circulation
C) Normal postnatal findings for a newborn
D) Rh HDFN

Question 30

Mixed-type AIHA is typically characterized by autoantibodies of which classes?

A) IgA and IgG
B) IgG and IgM
C) IgM and IgA
D) IgA and IgE

Question 31

Compare the differences in the activation of complement that can lead to intravascular hemolysis or extravascular hemolysis.

Question 32

A Group O, Rh-negative woman with no evidence of antibodies delivers her first child who shows a slightly decreased hemoglobin and the presence of spherocytes on the peripheral blood film. The DAT is positive with polyspecific AHG and anti-IgG. The baby is Group A, Rh negative and is slightly jaundiced with a bilirubin of 2.1 mg/dl. What is the most likely cause of the baby's jaundice?

A) Normal physiologic jaundice
B) Rh HDFN
C) ABO HDFN
D) Other type HDFN