ASCP MLS Blood Bank
A 10 mL fetal maternal hemorrhage in an Rh-negative woman who delivered an
Rh-positive baby means that the:
a. mother's antibody screen will be positive for anti-O
b. rosette test will be positive
c. mother is not a candidate for Rh immune globulin
d. mother should receive 2 doses of Rh immune globulin - ------------ANSWER: b.
The rosette screen will be positive if there is a FMH of 10 mL or more. A Kleihauer
Betke or flow cytometry should be performed to quantitate the FMH and determine if
additional doses of Rh immune globulin are needed to prevent immunization from
occurring.
A 10-year-old girl was hospitalized because her urine had a distinct red color. The
patient had recently recovered from an upper respiratory infection and appeared very
pale and lethargic. Tests
were performed with the following results:
hemoglobin: 5 g/dl. (50 g/L)
reticulocyte count: 15%
DAT: weak reactivity with poly-specific and anti-C3d: anti-lgG was negative
antibody screen: negative
Donath-Landsteiner test: positive; P- cells showed no hemolysls
The patient probably has:
a. paroxysmal cold hemoglobinuria (PCH)
b. paroxysmal nocturnal hemoglobinuria (PNH)
c. warm autoimmune hemolytic anemia
d. hereditary erythroblastic multinuclearity with a positive acidified serum test
(HEMPAS) - ------------ANSWER: a . The Donath-Landsteiner test is diagnostic for
PCH. The antibody is lgG and is biphasic: hemolysis occurs when the antibody is
incubated with cells and cold temperatures and then incubated at 37°C. Often the
antibody demonstrates specificity towards the high-incidence antigen P (not to be
confused with P1). The antibody screen is usually negative and the patient's red cells
are coated with complement.
A 10% red cell suspension in saline is used in a compatibility test. Which of the
following would most likely occur?
a. a false-positive result due to antigen excess
b. a false-positive result due to the prozone phenomenon
,c. a false-negative result due to the prozone phenomenon
d. a false-negative result due to antigen excess - ------------ANSWER: d. The
strength of agglutination is dependent upon optimal antigen to antibody ratio.
Excessive amount of antigen does not allow maximal uptake of antibody per red cell
and therefore agglutination is negatively affected leading to weaker or negative
results.
A 29-year-old male is hemorrhaging severely. He is AB, Rh-negative. 6 units of blood
are required STAT. Of the following types available in the blood bank, which would be
most preferable for crossmatch?
a. AB, Rh-positive
b. A, Rh-negative
c. A, Rh-positive
d. O, Rh-negative - ------------ANSWER: b. When group specific units of Red Blood
Cells are not available, group compatible units are selected. Since the patient is AB,
group A would be selected to conserve group O units for group O patients.
Rh·negative patients should receive Rh•negative units of red blood cells.
A 40-year-old man with autoimmune hemolytic anemia due to anti-E has a
hemoglobin level of 10.8 g/dL (108 g/L). This patient will most likely be treated with:
a. Whole Blood
b. Red Blood Cells
c. Fresh Frozen Plasma
d. no transfusion - ------------ANSWER: d. Transfusion should generally be avoided
except in cases of life-threatening anemia. A hemoglobin of 10.8 g/dL (108 g/L) is
not life-threatening, especially if the patient is not actively bleeding.
A 42-year-old male of average body mass has a history of chronic anemia requiring
transfusion support. Two units of Red Blood Cells are transfused. If the
pretransfusion hemoglobin was 7.0 g/dL (70 g/L), the expected posttransfusion
hemoglobin concentration should be:
a. 8.0 g/dL (80 g/L)
b. 9.0 g/dL (90 g/L)
c. 10.0 g/dL (100 g/L)
d. 11.0 g/dL (110 g/L) - ------------ANSWER: b. Each unit of RBCs is expected to
increase the hemoglobin level by l -1.5 g/dL (10-15 g/L).
A 56-year-old female with cold agglutinin disease has a positive direct antiglobulin
test (DAT). When the DAT is repeated using monospecific antiglobulin sera, which of
the following is most likely to be detected?
,a. IgM
b. IgG
c. C3d
d. C4a - ------------ANSWER: c. Cold agglutinin disease is associated with cold
reactive antibodies that typically activate complement. Cells that do not undergo lysis
due to complement activation have C3d attached to the red blood cells.
A 65-year-old woman experienced shaking, chills, and a fever of 102°F (38.9°C)
approximately 40 minutes following the transfusion of a second unit of Red Blood
Cells. The most likely explanation for the patient's symptoms is:
a. transfusion of bacterially contaminated blood
b. congestive heart failure
c. anaphylactic transfusion reaction
d. febrile transfusion reaction - ------------ANSWER: d. Febrile nonhemolytic
transfusion reactions occur in about 1% of transfusions, making it one of the most
common types of reaction. Neither transfusion-associated circulatory overload
(TACO) or anaphylactic
transfusion reactions are characterized by fever. Bacterially contaminated Red Blood
Cells are rare, and rapidly produce severe svmotoms upon transfusion.
A blood component prepared by thawing Fresh Frozen Plasma at refrigerator
temperature and removing the fluid portion is:
a. Plasma Protein Fraction
b. Cryoprecipitated AH F
c. Factor IX Complex
d. FP24 - ------------ANSWER: b. Cryoprecipitate is the fraction of plasma proteins
that precipitate when FFP is slowly thawed at 1°-6-C.
A blood component used in the treatment of hemophilia A is:
a. Factor VIII Concentrate
b. Fresh Frozen Plasma
c. Platelets
d. Whole Blood - ------------ANSWER: a. Patients with severe hemophilia A may
have spontaneous hemorrhages that are treated with Factor VIII concentrate.
A blood donor has the genotype: hh, AB. What is his red blood cell phenotype?
a. A
b. B
c. O
, d. AB - ------------ANSWER: c. The A and B structures can not be developed since
there is no H precursor substance due to the lack of the H gene in the blood donor.
A blood specimen from a pregnant woman is found to be group B, Rh-negative and
the serum contains anti-D with a titer of 512. What would be the most appropriate
type of blood to have available for
a possible exchange transfusion for her infant?
a. O, Rh-negative
b. O, Rh-positive
c. B, Rh-negative
d. B, Rh-positive - ------------ANSWER: a. Blood selected for exchange transfusion
should be ABO-compatible with the mother and baby, and antigen-negatitive.
Prenatal antihody titers above 16 or 32 are considered significant and the condition
of the fetus should be monitored.
A blood specimen types as A, Rh-positive with a negative antibody screen. 6 units of
group A, Rh-positive Red Blood Cells were crossmatched and 1 unit was
incompatible in the antiglobulin phase. The same result was obtained when the test
was repeated. Which should be done first?
a. repeat the ABO grouping on the incompatible unit using a more sensitive
technique
b. test a panel of red cells that possesses low-incidence antigens
c. perform a direct antiglobulin test on the donor unit
d. obtain a new specimen and repeat the crossmatch - ------------ANSWER: c. If a
patient is negative for clinically significant antibodies, and a single crossmatch is
incompatible, the incompatibility is either due to donor cells with a positive DAT or
the patient has an antibody to a low-incidence antigen that the donor's cells possess.
A cause for permanent deferral of blood donation is:
a. diabetes
b. residence in an endemic malaria region
c. history of jaundice of uncertain cause
d. history of therapeutic rabies vaccine - ------------ANSWER: c. Jaundice is a sign of
liver impairment, which might be due to HBV or HCV. Infection with HBV and HCV is
a cause for indefinite deferral.
A commonly used screening method for anti-HIV-1 detection is:
A 10 mL fetal maternal hemorrhage in an Rh-negative woman who delivered an
Rh-positive baby means that the:
a. mother's antibody screen will be positive for anti-O
b. rosette test will be positive
c. mother is not a candidate for Rh immune globulin
d. mother should receive 2 doses of Rh immune globulin - ------------ANSWER: b.
The rosette screen will be positive if there is a FMH of 10 mL or more. A Kleihauer
Betke or flow cytometry should be performed to quantitate the FMH and determine if
additional doses of Rh immune globulin are needed to prevent immunization from
occurring.
A 10-year-old girl was hospitalized because her urine had a distinct red color. The
patient had recently recovered from an upper respiratory infection and appeared very
pale and lethargic. Tests
were performed with the following results:
hemoglobin: 5 g/dl. (50 g/L)
reticulocyte count: 15%
DAT: weak reactivity with poly-specific and anti-C3d: anti-lgG was negative
antibody screen: negative
Donath-Landsteiner test: positive; P- cells showed no hemolysls
The patient probably has:
a. paroxysmal cold hemoglobinuria (PCH)
b. paroxysmal nocturnal hemoglobinuria (PNH)
c. warm autoimmune hemolytic anemia
d. hereditary erythroblastic multinuclearity with a positive acidified serum test
(HEMPAS) - ------------ANSWER: a . The Donath-Landsteiner test is diagnostic for
PCH. The antibody is lgG and is biphasic: hemolysis occurs when the antibody is
incubated with cells and cold temperatures and then incubated at 37°C. Often the
antibody demonstrates specificity towards the high-incidence antigen P (not to be
confused with P1). The antibody screen is usually negative and the patient's red cells
are coated with complement.
A 10% red cell suspension in saline is used in a compatibility test. Which of the
following would most likely occur?
a. a false-positive result due to antigen excess
b. a false-positive result due to the prozone phenomenon
,c. a false-negative result due to the prozone phenomenon
d. a false-negative result due to antigen excess - ------------ANSWER: d. The
strength of agglutination is dependent upon optimal antigen to antibody ratio.
Excessive amount of antigen does not allow maximal uptake of antibody per red cell
and therefore agglutination is negatively affected leading to weaker or negative
results.
A 29-year-old male is hemorrhaging severely. He is AB, Rh-negative. 6 units of blood
are required STAT. Of the following types available in the blood bank, which would be
most preferable for crossmatch?
a. AB, Rh-positive
b. A, Rh-negative
c. A, Rh-positive
d. O, Rh-negative - ------------ANSWER: b. When group specific units of Red Blood
Cells are not available, group compatible units are selected. Since the patient is AB,
group A would be selected to conserve group O units for group O patients.
Rh·negative patients should receive Rh•negative units of red blood cells.
A 40-year-old man with autoimmune hemolytic anemia due to anti-E has a
hemoglobin level of 10.8 g/dL (108 g/L). This patient will most likely be treated with:
a. Whole Blood
b. Red Blood Cells
c. Fresh Frozen Plasma
d. no transfusion - ------------ANSWER: d. Transfusion should generally be avoided
except in cases of life-threatening anemia. A hemoglobin of 10.8 g/dL (108 g/L) is
not life-threatening, especially if the patient is not actively bleeding.
A 42-year-old male of average body mass has a history of chronic anemia requiring
transfusion support. Two units of Red Blood Cells are transfused. If the
pretransfusion hemoglobin was 7.0 g/dL (70 g/L), the expected posttransfusion
hemoglobin concentration should be:
a. 8.0 g/dL (80 g/L)
b. 9.0 g/dL (90 g/L)
c. 10.0 g/dL (100 g/L)
d. 11.0 g/dL (110 g/L) - ------------ANSWER: b. Each unit of RBCs is expected to
increase the hemoglobin level by l -1.5 g/dL (10-15 g/L).
A 56-year-old female with cold agglutinin disease has a positive direct antiglobulin
test (DAT). When the DAT is repeated using monospecific antiglobulin sera, which of
the following is most likely to be detected?
,a. IgM
b. IgG
c. C3d
d. C4a - ------------ANSWER: c. Cold agglutinin disease is associated with cold
reactive antibodies that typically activate complement. Cells that do not undergo lysis
due to complement activation have C3d attached to the red blood cells.
A 65-year-old woman experienced shaking, chills, and a fever of 102°F (38.9°C)
approximately 40 minutes following the transfusion of a second unit of Red Blood
Cells. The most likely explanation for the patient's symptoms is:
a. transfusion of bacterially contaminated blood
b. congestive heart failure
c. anaphylactic transfusion reaction
d. febrile transfusion reaction - ------------ANSWER: d. Febrile nonhemolytic
transfusion reactions occur in about 1% of transfusions, making it one of the most
common types of reaction. Neither transfusion-associated circulatory overload
(TACO) or anaphylactic
transfusion reactions are characterized by fever. Bacterially contaminated Red Blood
Cells are rare, and rapidly produce severe svmotoms upon transfusion.
A blood component prepared by thawing Fresh Frozen Plasma at refrigerator
temperature and removing the fluid portion is:
a. Plasma Protein Fraction
b. Cryoprecipitated AH F
c. Factor IX Complex
d. FP24 - ------------ANSWER: b. Cryoprecipitate is the fraction of plasma proteins
that precipitate when FFP is slowly thawed at 1°-6-C.
A blood component used in the treatment of hemophilia A is:
a. Factor VIII Concentrate
b. Fresh Frozen Plasma
c. Platelets
d. Whole Blood - ------------ANSWER: a. Patients with severe hemophilia A may
have spontaneous hemorrhages that are treated with Factor VIII concentrate.
A blood donor has the genotype: hh, AB. What is his red blood cell phenotype?
a. A
b. B
c. O
, d. AB - ------------ANSWER: c. The A and B structures can not be developed since
there is no H precursor substance due to the lack of the H gene in the blood donor.
A blood specimen from a pregnant woman is found to be group B, Rh-negative and
the serum contains anti-D with a titer of 512. What would be the most appropriate
type of blood to have available for
a possible exchange transfusion for her infant?
a. O, Rh-negative
b. O, Rh-positive
c. B, Rh-negative
d. B, Rh-positive - ------------ANSWER: a. Blood selected for exchange transfusion
should be ABO-compatible with the mother and baby, and antigen-negatitive.
Prenatal antihody titers above 16 or 32 are considered significant and the condition
of the fetus should be monitored.
A blood specimen types as A, Rh-positive with a negative antibody screen. 6 units of
group A, Rh-positive Red Blood Cells were crossmatched and 1 unit was
incompatible in the antiglobulin phase. The same result was obtained when the test
was repeated. Which should be done first?
a. repeat the ABO grouping on the incompatible unit using a more sensitive
technique
b. test a panel of red cells that possesses low-incidence antigens
c. perform a direct antiglobulin test on the donor unit
d. obtain a new specimen and repeat the crossmatch - ------------ANSWER: c. If a
patient is negative for clinically significant antibodies, and a single crossmatch is
incompatible, the incompatibility is either due to donor cells with a positive DAT or
the patient has an antibody to a low-incidence antigen that the donor's cells possess.
A cause for permanent deferral of blood donation is:
a. diabetes
b. residence in an endemic malaria region
c. history of jaundice of uncertain cause
d. history of therapeutic rabies vaccine - ------------ANSWER: c. Jaundice is a sign of
liver impairment, which might be due to HBV or HCV. Infection with HBV and HCV is
a cause for indefinite deferral.
A commonly used screening method for anti-HIV-1 detection is:
