MMSC 409 practice chat gtp

1. Why is antibody identification performed?

A) To confirm blood type

B) To determine the specificity of unexpected antibodies

C) To monitor iron levels

D) To detect hemophilia

B) To determine the specificity of unexpected antibodies

2. What role does patient history play in evaluating antibodies?

A) It helps choose the best anticoagulant

B) It determines donor eligibility

C) It provides context for antibody development

D) It confirms ABO type

C) It provides context for antibody development

3. What is an antibody panel?

A) A screen for hemoglobin variants

B) A test using RBCs with known antigens to identify antibodies

C) A list of previous transfusions

D) A panel of platelet antibodies

B) A test using RBCs with known antigens to identify antibodies

4. Which test is more interpretive and specific?

A) Antibody screen

B) Antibody identification

C) ABO typing

D) Rh testing

B) Antibody identification

5. Why is an auto control tested in antibody identification?

A) To confirm blood type

B) To detect clotting disorders

C) To distinguish between auto- and alloantibodies

D) To identify leukocyte antibodies

C) To distinguish between auto- and alloantibodies

6. How do you rule out an antibody?

A) Use non-reactive homozygous antigen-positive cells

B) Use positive DAT test

C) Use cold autoabsorption

D) Use only heterozygous cells

A) Use non-reactive homozygous antigen-positive cells

7. Which rule is used to confirm an antibody?

A) Use 1 reactive and 1 non-reactive cell

B) Use ≥3 reactive and ≥3 non-reactive cells

C) Use only positive cells

D) Use hemoglobin electrophoresis

B) Use ≥3 reactive and ≥3 non-reactive cells

8. What does "++" indicate in an antibody panel?

A) Weak antigen expression

B) Homozygous antigen expression

C) Negative reaction

D) Auto control positive

B) Homozygous antigen expression

9. What does "+" typically indicate for antigen status?

A) Heterozygous expression

B) Double negative expression

C) High-titer antibodies

D) Negative antigen profile

A) Heterozygous expression

10. Which is an example of a homozygous phenotype?

A) M+N+

B) M+N-

C) Jka+Jkb+

D) K+k+

B) M+N-

11. Which antibody requires homozygous rule-outs?

A) Anti-Fya

B) Anti-Lea

C) Anti-K

D) Anti-P1

A) Anti-Fya

12. Which antibody can be ruled out using heterozygous cells?

A) Anti-E

B) Anti-K

C) Anti-Fyb

D) Anti-Jka

B) Anti-K

13. Why are homozygous cells used in rule-outs?

A) They are cheaper

B) They express stronger antigens

C) They are easier to read

D) They bind IgM better

B) They express stronger antigens

14. What does variable reaction strength in the same phase indicate?

A) Dosage effect

B) Bacterial contamination

C) IgA interference

D) ABO mismatch

A) Dosage effect

15. What does different strength in different phases indicate?

A) Only dosage

B) Improper centrifugation

C) Different antibody types or class switching

D) Hemoglobinopathy

C) Different antibody types or class switching

16. What helps identify antibodies in a panel?

A) Using a DAT test

B) Mixing with cold reagents

C) Matching reactivity patterns and zygosity

D) Checking platelet count

C) Matching reactivity patterns and zygosity

17. Why is antigen phenotyping performed?

A) To confirm pregnancy

B) To confirm the patient lacks the target antigen

C) To increase antibody binding

D) To predict RH genotype

B) To confirm the patient lacks the target antigen

18. Which is a clinically significant antibody?

A) Anti-Lea

B) Anti-K

C) Anti-I

D) Anti-M (cold-reactive)

B) Anti-K

19. What defines a clinically significant antibody?

A) Reacts at room temperature

B) Reacts at 37°C or AHG and may cause HTR/HDFN

C) Weak IgM reactivity

D) Positive DAT only

B) Reacts at 37°C or AHG and may cause HTR/HDFN

20. Why should donor cells be phenotyped?

A) To match gender

B) To find HLA types

C) To ensure compatibility with patient antibodies

D) To test for leukemia

C) To ensure compatibility with patient antibodies

21. When should donor units be phenotyped?

A) When a clinically significant antibody is identified

B) When DAT is negative

C) When the patient has O blood type

D) When no antibodies are found

A) When a clinically significant antibody is identified

22. What is a key concern with antibodies to high-frequency antigens?

A) Finding compatible donors is difficult

B) They are usually IgM

C) They don't require crossmatch

D) They're easily removed with enzymes

A) Finding compatible donors is difficult

23. Which is true of anti-P1?

A) It is IgG and reacts at AHG

B) It is IgM and reacts at IS phase

C) It reacts only at 37°C

D) It causes HDFN

B) It is IgM and reacts at IS phase

24. What is a likely cause of false antibody ID results?

A) Preanalytical error like mislabeling

B) Perfect wash steps

C) Over-centrifugation

D) Automated pipetting

A) Preanalytical error like mislabeling

25. What is an analytical error example?

A) Wrong patient ID

B) Skipping incubation or washing

C) Hemolysis from phlebotomy

D) Transcription error in EMR

B) Skipping incubation or washing

What are the main Lewis antigens?

A) Le^x and Le^y

B) Le^a and Le^b

C) H and Se

D) A and B

B) Le^a and Le^b

Which Lewis phenotype is most common in secretors?

A) Le(a+b−)

B) Le(a+b+)

C) Le(a−b+)

D) Le(a−b−)

C) Le(a−b+)

Why is the Le(a+b+) phenotype rare?

A) Genetic incompatibility

B) Le^b outcompetes Le^a for adsorption

C) Le^a is destroyed by enzymes

D) Le and Se suppress each other

B) Le^b outcompetes Le^a for adsorption

What gene is required to produce Le^a antigen?

A) Sese

B) Le (FUT3)

C) Hh

D) ABO

B) Le (FUT3)

Where are Lewis antigens synthesized?

A) Bone marrow

B) Spleen

C) Tissue and secreted into body fluids

D) RBC membranes directly

C) Tissue and secreted into body fluids

A person with Lele, Sese genotype will have which on RBCs?

A) No Lewis antigens

B) Le^b only

C) Le^a only

D) Le^a and Le^b

B) Le^b only

What does the Le(a−b−) phenotype indicate?

A) Secretor status

B) Lack of Lewis gene (lele)

C) Presence of anti-Le^a

D) Homozygosity for Le

B) Lack of Lewis gene (lele)

What class are most Lewis antibodies?

A) IgM

B) IgG

C) IgA

D) IgD

A) IgM

Why are Lewis antibodies described as "frequent and troublesome"?

A) They destroy fetal RBCs

B) They interfere with panels despite being clinically insignificant

C) They cause hemolytic disease

D) They bind complement strongly

B) They interfere with panels despite being clinically insignificant

How does neutralization help with Lewis antibodies?

A) Enhances reactivity

B) Removes Lewis activity to uncover other antibodies

C) Destroys RBCs

D) Prevents ABO mismatches

B) Removes Lewis activity to uncover other antibodies

Which is true about anti-Le^bH vs. anti-Le^bL?

A) They are identical

B) They have different specificities based on H antigen

C) Only Le^bL is IgG

D) Le^bH causes HDFN

B) They have different specificities based on H antigen

Why do Lewis antibodies rarely cause HDFN?

A) They destroy fetal RBCs

B) They are IgM and don't cross the placenta

C) They react at AHG only

D) They're enzyme sensitive

B) They are IgM and don't cross the placenta

What is the ISBT number for Le^a?

A) 003001

B) 007001

C) 008001

D) 005001

B) 007001

Who is most likely to form anti-Le^a?

A) Le(a+b+)

B) Le(a−b+)

C) Le(a−b−)

D) Le(a+b−)

C) Le(a−b−)

Why don't Le(a−b+) individuals form anti-Le^a?

A) Le^a isn't made at all

B) Le^a is secreted even if not on RBCs

C) They lack antibodies

D) They express Le^b only

B) Le^a is secreted even if not on RBCs

Which Duffy phenotype is most common in Black populations?

A) Fy(a+b+)

B) Fy(a−b+)

C) Fy(a−b−)

D) Fy(a+b−)

C) Fy(a−b−)

What protection does the Fy(a−b−) phenotype offer?

A) HIV resistance

B) Resistance to Plasmodium vivax

C) Influenza immunity

D) Resistance to HDFN

B) Resistance to Plasmodium vivax

What effect do enzymes have on Fy^a and Fy^b?

A) Enhance them

B) No effect

C) Destroy them

D) Reverse expression

C) Destroy them

Which Duffy antibody is more common and stronger?

A) Anti-Fy^a

B) Anti-Fy^b

C) Anti-Fy^3

D) Anti-Fy^5

A) Anti-Fy^a

Why don't Fy(a−b−) Black individuals produce anti-Fy^a or Fy^b?

A) They're immune suppressed

B) GATA mutation suppresses RBC expression but not tissue

C) They were transfused

D) They express Fy^3 instead

B) GATA mutation suppresses RBC expression but not tissue

Which Kidd phenotype is rarest?

A) Jk(a+b−)

B) Jk(a−b+)

C) Jk(a−b−)

D) Jk(a+b+)

C) Jk(a−b−)

Are Kidd antigens enzyme sensitive?

A) Yes

B) No, they're enzyme resistant

C) Sometimes

D) Only Jk3 is resistant

B) No, they're enzyme resistant

What is notable about Kidd antibodies?

A) Naturally occurring

B) Can cause delayed HTRs

C) Always IgM

D) Bind ABO antigens

B) Can cause delayed HTRs

Why use polyspecific AHG for Kidd antibodies?

A) It is cheaper

B) Kidd antibodies activate complement

C) IgM detection required

D) Kidd is IgA

B) Kidd antibodies activate complement

Which Kell antigen is more common?

A) K

B) k

C) Kp^a

D) Js^a

B) k

What is true of Kp^a and Js^a?

A) High frequency

B) Low frequency

C) Enzyme-sensitive

D) Only found in infants

B) Low frequency

What is the clinical significance of Kell antibodies?

A) Insignificant

B) Only found in males

C) Severe HDFN and HTR

D) IgM only

C) Severe HDFN and HTR

Which antigens are part of the MNSs blood group system?

A) D, C, E, c, e

B) Fyᵃ, Fyᵇ

C) M, N, S, s, U

D) Leᵃ, Leᵇ

C) M, N, S, s, U

What is the significance of the U antigen in the Black population?

A) It causes frequent transfusion reactions

B) It may be absent in some individuals, leading to anti-U formation

C) It prevents PCH

D) It is enhanced by enzymes

B) It may be absent in some individuals, leading to anti-U formation

What is the typical phenotype associated with anti-U production?

A) M+N+

B) S+s+

C) S-s-U-

D) U+M-N-

C) S-s-U-

Why is the MNSs system useful in paternity testing?

A) Antigens are inherited codominantly

B) It indicates blood type

C) It is only present in males

D) It's enzyme resistant

A) Antigens are inherited codominantly

What effect do enzymes have on M and N antigens?

A) No effect

B) Destroy them

C) Enhance them

D) Only affect N

B) Destroy them

Which antibody is commonly associated with dialysis patients?

A) Anti-U

B) Anti-N

C) Anti-S

D) Anti-Leᵇ

B) Anti-N

What are the typical characteristics of anti-M and anti-N antibodies?

A) Always IgG, warm-reactive

B) Often IgM, cold-reactive

C) Enzyme resistant

D) Cause severe HDFN

B) Often IgM, cold-reactive

Which lectin is used for anti-M detection?

A) Iberis amara

B) Ulex europaeus

C) Dolichos biflorus

D) None

A) Iberis amara

What is the ISBT number for U?

A) 003001

B) 005002

C) 007002

D) 002005

D) 002005

What are the main antigens of the P system?

A) P1, Pk, NOR

B) Leᵃ, Leᵇ

C) Fyᵃ, Fyᵇ

D) I, i

A) P1, Pk, NOR

P1 phenotype means:

A) Anti-P is present

B) No P1 antigen is expressed

C) P1 antigen is expressed

D) Only Pk is made

C) P1 antigen is expressed

What enhances P1 antigen detection?

A) DTT

B) Cold incubation

C) Enzymes

D) Acidification

C) Enzymes

What is the clinical significance of anti-P1?

A) Always causes HDFN

B) Usually IgM and clinically insignificant unless reactive at 37°C

C) Always causes HTR

D) Causes anti-D reactions

B) Usually IgM and clinically insignificant unless reactive at 37°C

Which antibody is associated with PCH (paroxysmal cold hemoglobinuria)?

A) Anti-P1

B) Anti-P (biphasic hemolysin)

C) Anti-PP1Pk

D) Anti-i

B) Anti-P (biphasic hemolysin)

What neutralizes anti-P1?

A) Ulex extract

B) Hydatid cyst fluid, pigeon egg white, P1 substance

C) Cold incubation

D) DTT

B) Hydatid cyst fluid, pigeon egg white, P1 substance

Which phenotype is associated with anti-PP1Pk production?

A) p phenotype

B) P2

C) P1

D) Fy(a−b−)

A) p phenotype

Which antigens are part of the I system?

A) I and i

B) P1 and P

C) Fyᵃ and Fyᵇ

D) M and N

A) I and i

Cord blood cells typically express:

A) High I

B) High i, low/no I

C) Only P1

D) Anti-i

B) High i, low/no I

What enhances detection of anti-I?

A) Neutralization

B) Enzyme treatment

C) Cold autoabsorption

D) IgG incubation

B) Enzyme treatment

What condition is associated with pathologic anti-I?

A) Mycoplasma pneumoniae

B) Epstein-Barr virus

C) Streptococcus

D) Hepatitis B

A) Mycoplasma pneumoniae

What condition is associated with anti-i?

A) Malaria

B) Parvovirus B19

C) Infectious mononucleosis

D) Cytomegalovirus

C) Infectious mononucleosis

49. Given serological reactions with reverse grouping cells, O cells, cord cells and auto control, what pattern suggests anti-I?

A) Strong reactions with cord cells only

B) Panagglutination, strong with adult O cells, weak with cord cells

C) No reaction with adult cells

D) Strong DAT with only IgA

B) Panagglutination, strong with adult O cells, weak with cord cells

Which Lutheran antigen is high frequency?

A) Luᵃ

B) Luᵇ

C) Lua-b-

D) Jkᵃ

B) Luᵇ

What pattern do Lutheran antibodies often show?

A) No agglutination

B) Mixed field agglutination

C) Strong, uniform agglutination

D) Cold-reactive hemolysis

B) Mixed field agglutination

What is the significance of anti-Luᵃ?

A) Always IgG

B) Severe HDFN

C) Usually IgM and clinically insignificant

D) Causes strong hemolysis

C) Usually IgM and clinically insignificant

Why aren't donor units routinely phenotyped for Luᵃ?

A) Phenotyping is inaccurate

B) Luᵃ is low frequency and anti-Luᵃ is rarely significant

C) All blood is Luᵃ positive

D) It's always IgG

B) Luᵃ is low frequency and anti-Luᵃ is rarely significant

1. Which Kell antigen is considered high frequency?

A) K

B) k

C) Kpᵃ

D) Jsᵃ

B) k

2. Which Lutheran antigen is low frequency?

A) Luᵃ

B) Luᵇ

C) K

D) S

A) Luᵃ

3. The Fy(a-b-) Duffy phenotype is associated with resistance to which disease?

A) Epstein-Barr virus

B) Plasmodium vivax malaria

C) COVID-19

D) Parvovirus B19

B) Plasmodium vivax malaria

4. Which antibody is associated with paroxysmal cold hemoglobinuria (PCH)?

A) Anti-P1

B) Anti-P (biphasic hemolysin)

C) Anti-i

D) Anti-Fy^a

B) Anti-P (biphasic hemolysin)

5. Anti-Fy^a and anti-Fy^b are what class of antibody?

A) IgM

B) IgG

C) IgA

D) IgD

B) IgG

6. Which antibody reacts more strongly with homozygous cells than heterozygous ones (shows dosage)?

A) Anti-Leᵇ

B) Anti-Fy^a

C) Anti-I

D) Anti-K

B) Anti-Fy^a

7. Which blood group antibody is usually IgM and reacts at cold temperatures?

A) Anti-P1

B) Anti-K

C) Anti-Fy^b

D) Anti-Jk^b

A) Anti-P1

8. Which antibody class is usually involved in severe HDFN?

A) IgM

B) IgG

C) IgA

D) IgE

B) IgG

9. What happens to M and N antigens when treated with enzymes?

A) Enhanced

B) Destroyed

C) Unaffected

D) Converted to P1

B) Destroyed

10. What effect do enzymes have on Kell antigens?

A) No effect (resistant)

B) Destroyed

C) Converted to Luᵃ

D) Reduced reactivity

A) No effect (resistant)

11. Why are Kidd antibodies dangerous in transfusion medicine?

A) They are IgM

B) They don't bind complement

C) They cause delayed HTRs and fall below detection

D) They don't crossmatch

C) They cause delayed HTRs and fall below detection

12. Which blood group system contains antigens destroyed by enzymes and is important for paternity testing?

A) Kell

B) Kidd

C) MNSs

D) Lutheran

C) MNSs

What type of reactions do anti-Leᵃ antibodies typically cause?

A) Severe HDFN

B) Interference in panels but rarely clinically significant

C) High-titer hemolysis

D) Anti-D mimicking

B) Interference in panels but rarely clinically significant

Which blood group antigen system is not produced on RBCs, but instead adsorbed from plasma?

A) Kell

B) Lewis

C) Lutheran

D) Duffy

B) Lewis

What enzyme treatment effect helps identify anti-Fy^a?

A) Enhancement of reactivity

B) Destruction of Duffy antigens

C) No effect

D) Mixed-field agglutination

B) Destruction of Duffy antigens

16. What is a characteristic of anti-Jk^a and anti-Jk^b?

A) IgG that binds complement and shows dosage

B) IgM that is enzyme sensitive

C) Naturally occurring antibodies

D) Detected with lectins

A) IgG that binds complement and shows dosage

17. Which antibody is often found in dialysis patients due to formaldehyde exposure?

A) Anti-U

B) Anti-Leᵃ

C) Anti-N

D) Anti-Jsᵇ

C) Anti-N

18. Which antibody causes mixed-field agglutination on panels?

A) Anti-Luᵃ

B) Anti-Fy^a

C) Anti-P1

D) Anti-I

A) Anti-Luᵃ

19. What is true of anti-K?

A) Only reacts in the cold

B) IgG, clinically significant, does not bind complement

C) Naturally occurring

D) Requires Le gene to form

B) IgG, clinically significant, does not bind complement

20. Which antigen is missing in some Black individuals, leading to possible anti-U formation?

A) P1

B) Fy^a

C) Leᵇ

D) U

D) U

What is the primary purpose of a major crossmatch?

A) Detect donor antibodies against patient RBCs

B) Detect patient antibodies against donor RBCs

C) Determine ABO type

D) Perform phenotype testing

B) Detect patient antibodies against donor RBCs

In which phase is a crossmatch only performed if the patient has a positive antibody screen?

A) Immediate spin

B) Antiglobulin (AHG) phase

C) Room temperature

D) Auto control

B) Antiglobulin (AHG) phase