BLOOD BANK a.

It is the only system in which antibodies are

normally produced for the antigens an
1. The reactivity of blood group A is confirmed by individual lacks
detecting the presence of which immunodominant b. ABO antibodies are capable of causing rapid,
sugar molecule? severe intravascular hemolysis
a. N-acetyl-D-neuraminic acid c. Reactions with ABO antibodies are the most
b. L-fucose common cause of transfusion-related death
c. N-acetyl-D-galactosamine d. ABO antibodies are often implicated in
d. N-acetyl-D-glucosamine severe hemolytic disease of the fetus and
e. D-galactose newborn
e. Routine ABO forward and reverse grouping is
2. The mating of parents of which two ABO phenotypes difficult to interpret and fraught with error
can potentially produce offspring with ALL of the
common four blood types? 8. A 26-year-old pregnant female is being tested prior to
a. AB and O a scheduled C-section tomorrow. Her cell grouping
b. AB and A (forward typing) is consistent with blood group O,
c. AB and B while her serum grouping (reverse grouping or "back-
d. AB and AB typing") appears to be group A. The most common
e. A and B reason for this type of ABO discrepancy is:
a. She has the Bombay phenotype
3. Bombay phenotype (Oh) individuals may have b. She is a non-secretor, so her plasma lacks A
antibodies with all the following specificities EXCEPT: c. Clerical errors or a sample mix-up
a. Anti-A d. Use of an uncalibrated centrifuge
b. Anti-B e. She has undiagnosed acute leukemia (AML)
c. Anti-H
d. Anti-O 9. An ABO discrepancy between forward and reverse
e. Anti-A,B grouping owing to weak-reacting or missing
antibodies could be BEST explained by which of the
4. Which cells agglutinate most strongly with Ulex following:
europaeus lectin? a. Patient has a subgroup of blood group A
a. O and A2 b. Patient is very old or very young
b. A1 and A2 c. Patient has acquired B phenotype
c. O and A1B d. Patient has antibodies to low incidence
d. B and A2B antigens
e. A1 and B e. Patient has antibodies against reagent
preservatives
5. Immune A and B alloantibodies differ from non-red
cell stimulated (naturally occurring) A and B 10. A blood donor has the genotype hh, AB. What is his
alloantibodies in that the immune antibodies: apparent red cell phenotype during routine forward
a. Are generally IgG rather than IgM and reverse group typing?
b. Are unable to cross the placenta a. A
c. Can be enhanced in reactivity by incubation b. B
at 4°C c. O
d. Cause direct agglutination at room d. AB
temperature e. Cannot be determined
e. Rarely cause clinical hemolysis
11. Approximately what percentage of group A individuals
6. Which ABH substances would you expect to find in the could be further classified as subgroup A1?
saliva of a group A secretor? a. 20%
a. H only b. 40%
b. H and A c. 60%
c. H and B d. 80%
d. H and O e. 99%
e. A only
12. Which of the following statements is TRUE regarding
7. Which of the following is the best explanation for why the A2 blood group?
the ABO system is the most important blood group a. Dolichos biflorus lectin agglutinates A2 but
system in transfusion safety? not A1 RBCs
 b. Ulex europaeus lectin will give stronger e. Most often results from inheritance of the
reactions with A1 than with A2 RBCs R0r' genotype
c. A2 RBCs have more H antigen than A1 RBCs
d. If anti-A1 is made by an A2 person, it is 18. Which of the following red blood cell abnormalities is
usually clinically significant associated with the Rhnull phenotype?
e. Most A2 individuals have a different form of a. Stomatocytes
anti-B than A1 individuals b. Ovalocytes
c. Acanthocytes
13. Which of the following genes codes for production of d. Spherocytes
the same basic antigen as the gene known as H? e. Schistocytes
a. O
b. Le 19. A patient has the following Rh phenotype:
c. Lu D:+ C:+ c:+ E:+ e:+
d. Se What is her most likely Rh genotype?
e. A a. R1R1
b. R1R2
14. The labels have come off of some of the reagent c. R2r
bottles in your transfusion service, so the ABO testing d. R0ry
reagents are just sitting there, label-less (and they just e. R2r”
look ridiculous!). A new lab scientist is trying to find
the anti-B, and he asks, "What color is anti-B?" You 20. A Caucasian patient has the following Rh phenotype:
reply: D:+ C:+ c:+ E:- e:+
a. “Green” Which of the following is his most likely Rh genotype?
b. “Orange” a. R1R0
c. “Blue” b. R1r
d. “Yellow” c. R0r
e. “Your mother was a hamster and your father d. R1R1
smelt of elderberries!” e. R0r’
f. ryr’
15. Which of the following statements is TRUE regarding
Hemolytic Disease of the Fetus/Newborn (HDFN) 21. An African American patient has the following Rh
caused by ABO antibodies? phenotype:
a. Fetal hemolysis is typically severe D:+ C:+ c:+ E:+ e:+ f:–
b. It rarely occurs during the first pregnancy Which of the following is her most likely Rh genotype?
c. It is most common with O mothers and A a. R1R2
babies b. R0Rz
d. A negative cord blood direct antiglobulin test c. R2r’
excludes it d. Rzr
e. It occurs less commonly than Rh HDFN e. R0ry

16. Name the three genes responsible for the production 22. An African American male potential blood recipient
of Rh antigens. has the following Rh phenotype:
a. RHAG, RH1, and RH2 D:+ C:+ E:– c:+ e:+
b. RHAG, DCE, and dce Which of the following is his most likely genotype?
c. RHAG, RHD, and RHCE a. R1r
d. RHD, RHCc, and RHEe b. R1R2
e. RHD, RHCE, and RHce c. R0r’
d. Rzry
17. Which of the following is TRUE regarding the weak D e. R1R0
phenotype?
a. Occurs when the D antigen has missing or 23. A 35-year-old O-negative male trauma patient
abnormal parts (epitopes) receives a transfusion of two units of O-positive red
b. Is easily distinguished from partial D by blood cells before his blood type is known. After his
serologic testing typing is completed, he is switched to O-negative, and
c. Was traditionally identified by an indirect he receives 6 additional type-specific RBC units. He
antiglobulin test survives and is transferred to the surgical ICU. Which
d. Are usually at risk for making anti-D if of the following is TRUE regarding his situation?
exposed to D+ blood a. He has an 80% chance of forming anti-D
 b. He is at high risk for an acute hemolytic e. Confirmatory testing of D-negative RBC by a
transfusion reaction transfusion service
c. Blood bank case review is needed to find the
reason for this error 28. Which of the following is TRUE about Anti-D?
d. He should immediately be given 20 vials of Rh a. It is primarily the IgG isotype rather than IgM
Immune Globulin (RhIG) b. It binds complement efficiently, leading to
e. He is unlikely to develop delayed hemolysis efficient hemolysis
c. It causes hemolysis with prominent
24. What percentage of blood specimens derived from schistocyte formation
those of European descent will have a positive d. It does not react with D positive cells treated
agglutination result with the anti-c reagent? with ficin
a. 15% e. It does not react with D positive cells treated
b. 35% with dithiothreitol (DTT)
c. 50%
d. 80% 29. Anti-G will react with red blood cells of each of the
e. 100% following phenotypes except:
a. D+C-
25. Which alloantibody is most likely to be produced if a b. D-C+
patient that has the Rh genotype of R1R1 is transfused c. D-C-
with red blood cells that have an Rh genotype of d. D+C+
R0R0? e. rG
a. Anti-D
b. Anti-C 30. If a patient had a positive direct antiglobulin test (DAT)
c. Anti-c with Anti-IgG, what would happen if you performed a
d. Anti-E Weak D test on the patient cells?
e. Anti-e a. A false-positive result
b. A false-negative result
26. A 63-year-old male presents with a positive antibody c. An indeterminate result
screen and clinical and serologic findings consistent d. A valid test results
with warm autoimmune hemolytic anemia. In e. An invalid Rh control test
addition, the reference lab technologist also identifies
an antibody that reacts stronger when the test RBCs 31. Which of the following phenotypes is seen MORE
are D-positive. The supervisor suggests the frequently in those of European descent than in those
technologist consider anti-LWa in addition to anti-D. of African descent?
Which of the following TWO techniques will MOST a. Fy(a-b-) phenotype
assist in differentiating between these two b. S-s-U phenotype
antibodies? c. R0 haplotype
a. Ficin/Papain treatment: LWa destroyed, D d. K+k+ phenotype
resistant e. Le(a-b-) phenotype
b. D-positive cord cells: anti-LWa negative, anti-
D reactive 32. A person with which one of the following red cell
c. Adsorption/elution with D-negative RBCs: phenotypes is expected to be resistant to Plasmodium
Anti-LWa detected, anti-D not detected vivax malaria?
d. Test RBCs treated with 0.2 M DTT: Anti-Lwa a. Fy(a-b-) phenotype
strongly reactive, anti-D nonreactive b. Rhnull phenotype
e. Test RBCs from pregnant donor: Anti-LWa c. McLeod phenotype
stronger, anti-D weaker d. S-s-U- phenotype
e. Le(a-b-) phenotype
27. In which of the following groups is Weak D testing
required if the initial D typing results appear negative? 33. Which of the following red blood cell antigens shows
a. Routine testing of pregnant female blood increased expression following incubation with
recipients proteolytic enzymes?
b. Rh typing of allogeneic (volunteer) whole a. Duffy antigens
blood donors b. MN antigens
c. Pretransfusion testing for sickle cell anemia c. Kidd antigens
patients d. Kell antigens
d. Pretransfusion testing for cardiac surgery e. Lutheran antigens
patients
34. You are told that a patient has the "McLeod 39. A 5-year-old child had an upper respiratory infection 5
Syndrome." Which of the following is most likely to be days ago. Today, his mother brought him to the
TRUE regarding the patient? emergency room because his urine was bright red this
a. The patient is susceptible to Streptococcus morning. Upon admission, he appears pale, his
infections hemoglobin is 6.4 g/dL, his urine and serum have free
b. The patient has stomatocytes in his hemoglobin, and his direct antiglobulin test (DAT) is
peripheral blood smear weakly positive with anti-C3 only (anti-IgG is negative).
c. The patient has increased levels of Kell blood Which of the following is most likely TRUE?
group antigens a. This child has Paroxysmal Nocturnal
d. The patient presents with seizures or Hemoglobinuria
involuntary movements b. The antibody specificity is most likely anti-P
e. The patient has an increased level of Kx c. The child should be tested for syphilis
antigen in his blood d. Transfusion should wait until antigen-
negative blood is available
35. Which of the following lectins is matched e. The antibody is most likely a high-titer IgM
appropriately with its target antigen? antibody
a. Vicea graminea: N antigen f. The diagnostic test is the "Donath-Wiener"
b. Dolichos biflorus: H antigen test
c. Salvia: A2 antigen
d. Ulex europaeus: A1 antigen
e. Ulex europaeus: Sda antigen

36. Which of the following red cell antigens is fully and

strongly expressed in red blood cells from a term
neonate?
a. I antigen
b. K antigen
c. A antigen
d. Lea antigen
e. P1 antigen

37. Which of the following is TRUE about the I blood group

system?
a. Auto-anti-i is associated with Mycoplasma
pneumonia
b. Auto-anti-I is associated with infectious
mononucleosis
c. i antigen is stronger on adult RBCs than
neonatal RBCs
d. Patients with auto-anti-I may require a
"prewarmed" crossmatch before transfusion
e. Antibodies in this system are usually clinically
significant

38. Which of the following is TRUE of the P1PK and GLOB

blood group systems?
a. The P antigen is the point of entry of
Plasmodium vivax into the red cell
b. Anti-P1 is a common cause of hemolytic
disease of the fetus/newborn
c. Anti-P1 is an insignificant antibody
neutralized by pigeon egg white fluid
d. The lack of antigens in these systems may
lead to the McLeod syndrome
e. Antibodies against these antigens are not
associated with hemolytic transfusion
reactions
ANSWER KEY and RATIONALE: ▪ both H and A substance in secretions if you
are group A. It is estimated that almost 80%
1. N-acetyl-D-galactosamine of the general population are secretors
▪ The A gene codes for production of N-
acetylgalactosaminyltransferase, an enzyme 7. ABO antibodies are capable of causing rapid, severe
which binds N-acetylgalactosamine (GalNAc) intravascular hemolysis
to the H structure (L-fucose). N- ▪ While ABO is famous for the reciprocal
acetylglucosamine is a sugar substance antibodies, it is not the only blood group with
thought to be useful in the treatment of "naturally occurring" antibodies.
Crohn’s Disease, osteoarthritis, and ▪ Transfusion-related acute lung injury (TRALI)
inflammatory bowel disease. is currently the most common cause of
transfusion-related death (though hemolytic
transfusion reactions are second).
2. A and B
▪ HDFN caused by ABO antibodies is generally
▪ If you assume “AO” as the genotype for one
mild.
parent and “BO” for the other, all four blood
types are possible in the offspring:
8. Clerical errors or a sample mix-up
▪ Bombay phenotypes are extremely rare.
▪ Secretor status will not affect the ability to
detect A and B antigens on red cells.
▪ Uncalibrated centrifuges are likely not
affected by over- or under- centrifugation.
▪ Group A patients with AML would be less
common issue than a sample integrity issue.
3. Anti-O
▪ Bombay phenotype and the Bombay 9. Patient is very old or very young
genotype (hh), mean that an individual is ▪ Elders and youngsters can have either
missing the H structure both on RBCs as well depressed or delayed natural expression of
as in plasma and secretions (the Bombay isoagglutinins.
person is a non-secretor, or sese). Since an ▪ Group A subgroups often lead to missing red
intact H structure is a prerequisite for cell (forward) reactions, and the acquired B
addition of the A and B antigens, you will then phenotype results in extra red cell reactions;
be able to deduce that the following neither typically leads to missing antibody
antibodies can be present in the serum of a reactions.
Bombay individual simply because you know ▪ Antibodies to low incidence antigens or
the corresponding antigen is missing: anti-A, reagents would give extra antibody reactions
anti-B, anti-A,B, and anti-H. O, of course, is rather than missing reactions.
not an antigen, it’s the lack of A and B
antigens, so anti-O is not a legitimate 10. O
antibody. ▪ Individuals who lack at least one H allele (i.e.,
hh genotype) cannot make the "H antigen."
4. O and A2 ▪ As a result, the A and B red cell antigens that
▪ The main blood groups agglutinate with the should have been made due to this donor's
following relative strength with anti-H or Ulex AB genotype are not formed ("no H, no A or
lectin: O > A2 > B > A2B > A1 > A1B. B"). This person’s red cells would appear to
be group O ("Bombay" or "Para-Bombay).
5. Are generally IgG rather than IgM
▪ Naturally occurring antibodies (IgM class) are 11. 80%
not able to cross the placenta, enhanced in ▪ The vast majority of group A patients are
reactivity by incubation at 4C, and can cause either subgroup A1 (about 80%) or A2 (about
direct agglutination at room temperature. 20%).
These antibodies are not usually capable of
causing clinical hemolysis. IgG antibodies can 12. A2 RBCs have more H antigen than A1 RBCs
cross the placenta and are not very reactive ▪ The major difference between the A1 and A2
(if at all) at 4C and room temperature. subgroups is quantitative; A1 RBCs have
about five times more A antigen than A2
6. H and A RBCs (and, as a result, much less H antigen).
13. Se 18. Stomatocytes
▪ The Se (or “secretor”) gene product is an ▪ Stomatocytes ("mouth cells") are associated
enzyme that assists in adding fucose sugar to with Rhnull.
a glycoprotein chain called a "type 1 chain." ▪ Schistocytes seen in intravascular hemolysis.
This results in the formation of the "H ▪ Spherocytes seen in extravascular hemolysis.
antigen" on these chains, which are found ▪ Ovalocytes in iron-deficiency anemia.
primarily in secretions and plasma. ▪ Acanthocytes in the Mcleod Syndrome.

14. “Yellow” 19. R1R2

▪ Blue Angel, Yellow Bird
▪ Anti-A is colored “blue”, while Anti-B is
colored “yellow”.

15. It is most common with O mother and A babies.

▪ HDFN caused by ABO incompatibility
between mother and child is, in fact, the
most common form of HDFN.
▪
▪ ABO HDFN is seen with a group O mother and
a group A or B child. Group O individuals carry 20. R1r
IgG ABO antibodies that, unlike the primarily 21. R1R2
IgM antibodies in non-group O people, are 22. R1R0
transported across the placenta and enter
the fetal circulation. These antibodies (either 23. He is unlikely to develop delayed hemolysis
anti-A, anti-B, or anti-A,B) are "naturally ▪ taas kaayo to summarize, check bbguy.org
occurring," like all ABO antibodies, so the
interaction may occur during the first 24. 80%
pregnancy (unlike the classic form of HDFN ▪ (80%) Caucasians = positive for the c antigen
due to Rh antibodies, which usually occurs in ▪ The c antigen is present in 96% of those of
second pregnancies and beyond). African descent, and 47% of those of Asian
▪ However, the relatively weak ABO antigen descent.
expression on the surface of fetal and
neonatal red cells means that the clinical and 25. Anti-c
laboratory sequelae (including hemolysis) of ▪ A patient has the opportunity to produce an
ABO HDFN are usually not severe. In fact, alloantibody if exposed to a red blood cell
affected babies may have a negative direct antigen they lack on their own RBCs. In this
antiglobulin test (DAT). case, our patient has the Rh genotype R1R1
▪ As a result, the patient lacks the antigens E
16. RHAG, RHD, and RHCE and c, and is exposed to red blood cells with
▪ RHD and RHCE = located on chromosome 1. the Rh genotype of R0R0 (Dce/Dce). The
▪ RHD codes for the presence or absence of the transfused red blood cells carry the c antigen,
D antigen. and the patient lacks c.
▪ RHCE has 4 main alleles to cover the
inheritance of C/c and E/e: RHCe, RHCE, 26. Adsorption/elution with D-negative RBCs: Anti-LWa
RHce, and RHcE detected, anti-D not detected
▪ RHAG (Rh associated glycoprotein) is located ▪ LW antigens are expressed strongly on D-
on chromosome 6. The presence of this gene positive cells but only weakly on D-negative
allows the proteins resulting from RHD and cells, (so weakly, that it may require
RHCE to be incorporated into the RBC adsorption and elution of the antibody to
membrane. prove an LW antigen is present)
▪ Absence of RHAG is known as “Rhnull”.
27. Rh typing of allogeneic (volunteer) whole blood
17. Was traditionally identified by an indirect antiglobulin donors
test ▪ Weak D testing must be performed on all
▪ Weak D (formerly known as "Du") occurs blood donors who test initially D-negative on
when a D-positive person has fewer D routine Rh typing.
antigens on their red blood cells than normal. ▪ If D antigen testing was stopped at the
▪ taas kaayo to summarize, check bbguy.org immediate spin phase on a blood product
that is actually from a donor with the Weak D
 phenotype, that product would falsely be ▪ Duffy, Lutheran, M and N, and Lutheran
labeled as "D-negative" when it is actually D- antigens show decreased expression
positive. Since the falsely labeled product following exposure of red cells to proteolytic
would most likely be transfused to a D- enzymes.
negative patient, the patient could make ▪ On the other hand, the same enzymes lead to
immune anti-D as a result. When performing stronger expression of Rh, and Kidd (Jk), and
pre-transfusion testing on patients, however, all ABO-related antigens.
the weak D test is not required. A patient that
is D-negative at the immediate spin phase 34. The patient presents with seizures or involuntary
will usually receive D-negative blood movements
products. Transfusing a D-negative blood ▪ The "McLeod Syndrome" is caused by
product to a patient that is really weak D absence of an antigen known as "Kx." This
positive will not cause the patient any syndrome is quite rare and is seen almost
adverse effects of transfusion due to the D exclusively in males.
antigen. Finally, weak D testing is not ▪ People with McLeod have abnormal RBCs, in
required when a transfusion service is particular acanthocytes (not stomatocytes).
confirming the Rh type of RBC units labeled ▪ Affected adults may develop a neurological
as D-negative. disorder resembling Huntington’s Disease
(chorea), seizures, cardiomyopathy, and a
28. It is primarily the IgG isotype rather than IgM poorly defined muscular abnormality with
▪ Anti-D is an IgG antibody that can cause elevated creatine kinase levels.
hemolytic disease of the fetus/newborn
(HDFN) and hemolytic transfusion reactions. 35. Vicea graminea: N antigen
▪ The D antigen is not destroyed by treatment ▪ Dolichos biflorus: Agglutinates RBCs of A1
with either enzymes (like ficin) or sulfhydryl phenotype
reagents (like DTT), so anti-D would still react ▪ Ulex europaeus: Agglutinates RBCs carrying H
with D-positive cells following treatment with antigen (more H, more agglutination)
either reagent. ▪ Vicea graminea: Agglutinates RBCs carrying N
▪ Anti-D is not an efficient complement- antigen
binding antibody, so the hemolysis caused by
incompatibility tends to be extravascular. 36. K antigen
▪ ABO antigens, while present on fetal and
29. D-C- neonatal RBCs, are not fully developed until
▪ taas kaayo to summarize, check bbguy.org between age 2 and 4.
▪ The I antigen is found on adult RBCs, while i
30. A false-positive result antigen is strongly present on fetal and
▪ Weak D test is nothing more than an indirect neonatal RBCs.
antiglobulin test (IAT). Cells that are coated ▪ Lewis antigens are also not found in
with IgG will agglutinate whenever you add a significant quantities on neonatal RBCs; this
reagent that contains Anti-IgG, as is done in is part of the reason that Lewis antibodies
the last step of an IAT. Anti-IgG is added in don’t usually cause hemolytic disease of the
both the direct and indirect antiglobulin newborn.
tests. ▪ P1 antigens, being built on similar chains as
▪ Cells that have a positive DAT will agglutinate ABO antigens, are likewise weakly expressed
in the antiglobulin phase in an IAT. at birth.
▪ The patient cells will give false-positive ▪ Kell antigens, on the other hand, are well-
agglutination during the Weak D test since expressed on newborn RBCs, as well as on
Anti-IgG is added prior to reading the AHG RBC precursors.
phase of testing.
37. Patients with auto-anti-I may require a "prewarmed"
31. K+k+ phenotype crossmatch before transfusion
▪ I and i antigens typically cause issues with the
32. Fy(a-b-) phenotype formation of "cold-reacting" antibodies,
▪ The Fy(a-b-) phenotype is associated with usually cold-reacting autoantibodies.
resistance to P. vivax infections. ▪ Although such antibodies are very common,
most of them do NOT cause hemolysis.
33. Kidd antigens ▪ Once the antibodies are found, however, it
may be difficult to find blood that is
 crossmatch-compatible without warming up
the reaction mixture first ("prewarmed
crossmatch").

38. Anti-P1 is an insignificant antibody neutralized by

pigeon egg white fluid.
▪ The P antigen is the point of entry for
Parvovirus B19 (not P. vivax) into the red cell
▪ The P1 antigen is found in hydatid cyst fluid
and pigeon egg whites (either fluid can be
used to neutralize anti-P1)
▪ Most examples of anti-P or anti-P1 are
benign, naturally occurring, IgM class
antibodies that are boring as heck (no
hemolytic transfusion reactions and no
hemolytic disease of the fetus/newborn)
▪ One example of anti-P associated with
paroxysmal cold hemoglobinuria is not so
boring (see next question)
▪ Very rare persons lack all three P-related
antigens (P, P1, and Pk), and as a result, make
an antibody against all three (anti-PP1Pk)
that CAN cause hemolytic transfusion
reactions and spontaneous abortions when
present in pregnant ladies

39. The antibody specificity is most likely anti-P

▪ This case is a classic presentation of
Paroxysmal Cold Hemoglobinuria (PCH), a
transient autoimmune hemolysis that most
frequently occurs in children in association
with a viral infection.
▪ PCH is caused by an unusual IgG (not IgM)
antibody that reacts in a very strange way.
▪ Most IgG antibodies react with their target
antigens at body temperature (37C), but not
this antibody! This IgG, known famously as
the "Donath-Landsteiner biphasic hemolysin"
binds to the P antigen on the patient's own
RBCs in cold temperatures (4C in the
laboratory, and in the cooler extremities in
the body), and fixes complement to the
surface of the RBC. The antibody then
dissociates and hemolyzes the red cell when
the temperatures get warmer!