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120 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
D. Corticosteroids as solitary therapy.
E. Expectant observation.
________________________________ _______________________________
夝
Question 11: Which of the following is a UNIQUE role of red cell transfusion in
sickle cell patients?
A. Increasing the viscosity of blood to ensure appropriate oxygenation.
B. Slowing transit of oxygen-carrying cells to ensure appropriate oxygenation.
C. Decrease the amount of toxic hemoglobin F.
D. Decrease the percentage of sicklable hemoglobin.
E. Increase expression of alternative hemoglobins.
________________________________ _______________________________
夝
Question 12:
Which of the following statements regarding sickle cell patients is true?
A. Splenomegaly is exceptionally rare in children.
B. Surgical splenectomy should be performed before symptoms of splenic seques-
tration.
C. Acute splenic sequestration invariably follows autosplenectomy.
D. Fibrosis of the spleen is unrelated to autosplenectomy.
E. Acute red cell splenic sequestration is a significant cause of death in early
childhood sickle cell disease patients.
________________________________ _______________________________
夝
Question 13: What is the most common inciting cause of acute chest syndrome in
sickle cell patients?
A. Pulmonary infarction.
B. Fat embolism.
C. Unknown.
D. Trauma.
E. Infection.
________________________________ _______________________________
夝
Question 14: Which of the following sickle-cell-associated symptoms/syndromes is
associated with ASPEN syndrome?
A. Priapism.
B. Acute chest syndrome.
SPECIAL TRANSFUSION SITUATIONS 121
C. Acute splenic sequestration.
D. Salmonella osteomyelitis.
E. Aplastic crisis.
________________________________ ________________________________
夝
Question 15: Which of the following is NOT a common cause for transfusion in
sickle cell disease?
A. Pregnancy.
B. Osteomyelitis.
C. Stroke.
D. Surgery.
E. Acute chest syndrome.
________________________________ ________________________________
夝
Question 16: In the STOP (Stroke Prevention Trial in Sickle Cell Anemia) Trials what
percentage of hemoglobin S was established as a target for prophylaxis of stroke in
sickle cell patients?
A. 10%
B. 30%
C. 50%
D. 70%
E. 92%
________________________________ ________________________________
夝
Question 17: What diagnostic modality is currently believed to be the most sensi-
tive in predicting stroke risk in sickle cell patients?
A. Transcranial Doppler ultrasound.
B. Magnetic resonance imaging.
C. Magnetic resonance angiography.
D. Chest x-ray.
E. Family history.
________________________________ ________________________________
夝
Question 18: Prophylactic transfusion of sickle cell patients is generally agreed to
be effective in which of the following situations?
A. Prevention of early first trimester pre-term labor.
122 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
B. Prevention of intrauterine growth retardation.
C. Prevention of pulmonary infarction in elective surgery patients.
D. Prevention of complications in vitreoretinal surgery.
E. Prevention of complications in pediatric surgery.
________________________________ _______________________________
夝
Question 19: Which of the following statements regarding massive transfusion is
true?
A. Defined as a full blood volume replacement within 48 hours.
B. Extremely rare incidence of coagulopathy.
C. Despite replacement of entire calculated red cell volume up to 1/3 of original
blood volume remains.
D. No role for Cryoprecipitated AHF.
E. Measuring platelet counts 15 minutes after transfusion is not recommended for
monitoring.
________________________________ _______________________________
夝
Question 20: Which of the following scenarios is NOT an appropriate indication for
a platelet transfusion?
A. A patient undergoing a general surgery or invasive procedure with a platelet
count of less than 50,000/L.
B. A patient undergoing ophthalmic or neurosurgery with a platelet count of less
than 100,000/L.
C. A bleeding patient who has a congenital or acquired platelet function defect.
D. A patient who underwent cardiothoracic surgery and continues to have signifi-
cant chest tube drainage despite a relatively normal platelet count on CBC.
E. A patient who demonstrates platelet refractoriness.
________________________________ _______________________________
夝
Question 21: What would be the expected incremental increase in platelet count
after transfusion of a single apheresis platelet unit to an otherwise healthy adult?
A. 1,000 to 5,000.
B. 10,000 to 20,000.
C. 30,000 to 50,000.
D. At least 100,000.
E. 100,000 to 300,000.
SPECIAL TRANSFUSION SITUATIONS 123
________________________________ ________________________________
夝
Question 22: What is the primary cause of immunologic platelet refractoriness?
A. Recipient D antibodies.
B. Recipient ABO antibodies.
C. Recipient HPA-5b antibodies.
D. Recipient HPA-1a antibodies.
E. Recipient Class I HLA antibodies.
________________________________ ________________________________
夝
Question 23: Which disorder shares many characteristics with posttransfusion pur-
pura?
A. Sickle cell anemia.
B. Neonatal alloimmunine thrombocytopenia.
C. Hermansky-Pudlak syndrome.
D. Heparin-induced thrombocytopenia.
E. Idiopathic thrombocytopenic purpura.
________________________________ ________________________________
夝
ANSWERS
Question 1: Which statement about hemolytic disease of the fetus and newborn
(HDFN) is true?
A. It generally occurs during the first trimester.
B. If severe, it results in extramedullary hematopoiesis.
C. It may result in hypoxia-induced damage to the brain and spinal column.
D. The fetus is at risk for developing kernicterus secondary to hyperbilirubinemia
and low levels of glucuronyl transferases.
E. The neonate is at risk for developing hydrops fetalis secondary to anemia.
B. This is the only correct answer. Transplacental transport of antibodies is slow
before the third trimester, so HDFN is rare before the third trimester. Hypoxia-
induced damage affects the heart and liver. Neonates (not fetuses) are at risk for
hyperbilirubinemia and kernicterus. Because bilirubin crosses the placenta and is
filtered by the mother, hyperbilirubinemia and kernicterus are potential problems
after birth. Conversely, it is the fetus not the neonate that is at risk for developing
hydrops fetalis.
124 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
________________________________ _______________________________
夝
Question 2:
Which statement is true about the antigens/antibodies that cause HDFN?
A. The two most significant antigens associated with HDFN are the D antigen and
the ABO antigens.
B. An Rh-negative mother will rarely have an Rh-positive fetus.
C. A K-negative mother will likely have a K-positive fetus.
D. RhIG is a monoclonal anti-D IgM antibody preparation given subcutaneously.
E. RhIG dose should be doubled for a woman who has already been sensitized to
D antigen.
A. This is the correct answer. The chance of a D-negative mother having a D-posi-
tive child is relatively high due to the high frequency of the D antigen (85%). Con-
versely, the antigen frequency of Kell is low, making it less likely that a Kell-negative
mother would have a Kell-positive child. RhIG used to prevent the development of a
maternal D alloantibody is IgG. There is no good evidence that doubling the dose of
RhIG is helpful in the prevention of anti-D development in a woman who has
already been sensitized to D antigen.
________________________________ _______________________________
夝
Question 3: Which statement is NOT true about the administration of RhIG to Rh-
negative females?
A. It should be given at 28 weeks’ gestation to Rh-negative, antibody-negative,
pregnant females who may be carrying Rh-positive fetuses.
B. It may or may not be given again within 72 hours of delivery depending on the
Rh type of the neonate’s cord blood.
C. A 300-g dose (one vial) is enough to prevent immunization of 15 mL of fetal
red cells.
D. RhIG can be given beyond the 72-hour period after delivery, but the efficacy is
uncertain.
E. If the fetus is Rh-positive, fetal rosette testing should be performed immediately
to accurately quantify the amount of fetomaternal hemorrhage.
E. A fetal cell screen (rosette test) is the first test that should be performed. It is a
much simpler test to determine if fetomaternal hemorrhage in excess of 15 mL of
fetal red cells (the amount covered by 1 vial of RhIG) has occurred. Kleihauer-Betke
or flow cytometry testing are both more costly and time-consuming to conduct, and
do not need to be performed if the fetal cell screen is negative. The Kleihauer-Betke
test, however, is a quantitative test unlike the rosette test, which is a qualitative test
only.
SPECIAL TRANSFUSION SITUATIONS 125
________________________________ ________________________________
夝
Question 4:
Which statement about antigen/antibodies that can cause HDFN is true?
A. Pregnant females with group AB blood are most at risk for HDFN.
B. HDFN due to ABO antibodies is usually severe because the A and B antigens
are strongly expressed at birth.
C. Approximately 95% of cases of HDFN are due to antibodies to antigens other
than Rh antigens.
D. When given to the mother within 72 hours after delivery, RhIG can protect
against sensitization to Kell antigens on fetal red cells.
E. After D and ABO antibodies, the next most important causes of HDFN are anti-
K and anti-c.
E. This is the only correct answer. Women who are group O are more likely to have
anti-A and anti-B and are therefore at the highest risk for anti-ABO HDFN (although
it is usually mild). RhIG doesn’t provide any significant protection against Kell, Kidd,
Duffy, or Diego antigens, which are also associated with HDFN.
________________________________ ________________________________
夝
Question 5: A G1P0 mother at 10 weeks is at her first obstetric visit with a brand
new family practitioner. The mother’s type and screen results reveal that she is O
negative. In the appropriate management of this patient, what should be the practi-
tioner’s next step?
A. Administer RhIG at 28 weeks.
B. Perform another antibody screen at 28 weeks.
C. Ensure she was tested for the presence of weak D.
D. Measure amniotic fluid bilirubin levels.
E. Consult a pathologist for clinical advice.
C. It is important to make sure the woman really is Rh negative and not Rh positive
with weak D expression. Otherwise, she’s going to be receiving two or more unnec-
essary intramuscular injections.
________________________________ ________________________________
夝
Question 6: If a clinically significant antibody is detected at any stage during the
testing of an obstetric patient, what should be the very next step?
A. Titer the antibody.
B. Perform amniocentesis to determine bilirubin level.
C. Perform PUBS to determine bilirubin level.
126 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
D. Perform intrauterine transfusion.
E. Perform molecular studies on amniocytes.
A. The next step is to titer the antibody. If the anti-D titer is 1:16 or higher at 20
weeks, or if there is a twofold increase in titer over time, more aggressive manage-
ment is indicated, which may include one or more of the other choices listed above.
________________________________ _______________________________
夝
Question 7: An obstetric patient has a high or rising antibody titer. The decision is
made to perform fetal middle cerebral artery (MCA) Doppler flow studies to detect
fetal anemia. Which of the following statements about this procedure is true?
A. Decreased flow rates indicate the presence of anemia.
B. The value obtained for the MCA is plotted on a Liley curve.
C. The MCA is a noninvasive technique.
D. The sensitivity is less than 85%.
E. MCA Doppler flow studies should be preceded by percutaneous umbilical
blood sampling.
C. MCA Doppler flow studies are supplanting amniotic fluid bilirubin in the assess-
ment of fetal anemia because they are noninvasive and have 100% sensitivity. Fetal
anemia is suggested on Doppler by increased flow rates. Liley curves are used for
plotting bilirubin measurements to assist with management decisions.
________________________________ _______________________________
夝
Question 8: Which statement about intrauterine transfusion is NOT true?
A. O-negative blood is always given.
B. The transfused RBCs should not contain any antibodies directed against fetal
red cell antigens.
C. The transfused RBCs should be irradiated.
D. The transfused RBCs must be compatible with any maternal antibodies.
E. The transfused RBCs should be concentrated to a hematocrit of 85-90% by
removal of plasma.
A. The unit selected should always be group O but the remaining typing depends on
compatibility with the maternal antibody(ies). Due to the relatively weak immune
system of the fetus, it is recommended that the blood transfused be CMV-negative
and irradiated.
SPECIAL TRANSFUSION SITUATIONS 127
________________________________ ________________________________
夝
Question 9: Which of the following antigens is the most common specificity for
neonatal/fetal alloimmune thrombocytopenia (NAIT/FAIT)?
A. HPA-1a.
B. HPA-1b.
C. HPA-1c.
D. HPA-2.
E. HPA-47.
A. HPA-1a, formerly known as Pl
A1
, is present in 98% of platelets. Given the high
incidence, a mother who does not bear the HPA-1a antigen is likely to have a child
that does. Sensitization of the mother by exposure to the antigen present on fetal
platelets is responsible for the formation of the anti-HPA-1a. A small portion of cases
have been attributed to anti-HPA-5b.
________________________________ ________________________________
夝
Question 10: What is the most appropriate manner to manage a pregnant woman
with a history of a previous conception affected by NAIT/FAIT?
A. RhIG 300 μg, one dose.
B. IVIG alone, but only in emergent situations.
C. IVIG, with or without corticosteroids.
D. Corticosteroids as solitary therapy.
E. Expectant observation.
C. There is no great therapy in this situation. A significant percentage (up to 38%) of
fetuses do not respond to IVIG and there is a lag of several days before a suitable
response. Corticosteroids help to bridge that gap. An alternative therapy is intrauter-
ine transfusion of antigen-negative platelets. It must be kept in mind that due to the
98% incidence of the HPA-1a antigen, finding antigen-negative platelets may be dif-
ficult. The best source is often the mother.
________________________________ ________________________________
夝
Question 11: Which of the following is a UNIQUE role of red cell transfusion in
sickle cell patients?
A. Increasing the viscosity of blood to ensure appropriate oxygenation.
B. Slowing transit of oxygen-carrying cells to ensure appropriate oxygenation.
C. Decrease the amount of toxic hemoglobin F.
128 PRACTICAL SELF-ASSESSMENT FOR TRANSFUSION MEDICINE PROFESSIONALS
D. Decrease the percentage of sicklable hemoglobin.
E. Increase expression of alternative hemoglobins.
D. The percentage of sicklable hemoglobin (HbS or HbC, most commonly) can be
reduced through transfusion with red cells that lack any sickling hemoglobin. This
decreases the likelihood of sickling under oxygen tension, which can lead to irre-
versible sickling and further increases in viscosity. Hemoglobin F does not usually
get incorporated into hemoglobin complexes along with sickling hemoglobin.
________________________________ _______________________________
夝
Question 12:
Which of the following statements regarding sickle cell patients is true?
A. Splenomegaly is exceptionally rare in children.
B. Surgical splenectomy should be performed before symptoms of splenic seques-
tration.
C. Acute splenic sequestration invariably follows autosplenectomy.
D. Fibrosis of the spleen is unrelated to autosplenectomy.
E. Acute red cell splenic sequestration is a significant cause of death in early
childhood sickle cell disease patients.
E. Acute splenic sequestration and subsequent hypovolemic shock are a significant
cause of death in early childhood patients with sickle cell disease. Although surgical
splenectomy can be considered for patients who have had splenic sequestration cri-
ses, it is not usually recommended as a universal prophylactic measure. Acute
splenic sequestration usually occurs in patients less than 2 years old before the fibro-
sis and autosplenectomy typically occur. Before the development of fibrosis, most
patients display splenomegaly.
________________________________ _______________________________
夝
Question 13: What is the most common inciting cause of acute chest syndrome in
sickle cell patients?
A. Pulmonary infarction.
B. Fat embolism.
C. Unknown.
D. Trauma.
E. Infection.
C. Unfortunately in almost half of the cases of acute chest syndrome the cause is
unknown. The most commonly attributed precipitating cause of ACS is infection.
The syndrome presents with cough, chest pain, and symptomatic hypoxemia. There
is usually a diffuse pulmonary infiltrate present on chest x-ray. It can progress rap-
idly and cause a subsequent neurologic event, such as stroke. Although transfusion
SPECIAL TRANSFUSION SITUATIONS 129
with non-sickling red cells is effective, exchange transfusion may be indicated in
rapidly progressive cases.
________________________________ ________________________________
夝
Question 14: Which of the following sickle-cell-associated symptoms/syndromes is
associated with ASPEN syndrome?
A. Priapism.
B. Acute chest syndrome.
C. Acute splenic sequestration.
D. Salmonella osteomyelitis.
E. Aplastic crisis.
A. ASPEN syndrome stands for A
ssociation of Sickle cell disease, Priapism,
E
xchange transfusion, and Neurologic events. The risk of ASPEN syndrome is high-
est following exchange transfusion for priapism in sickle cell patients. The symptoms
involve headache, seizure, hemiparesis, and a requirement for ventilator support.
________________________________ ________________________________
夝
Question 15: Which of the following is NOT a common cause for transfusion in
sickle cell disease?
A. Pregnancy.
B. Osteomyelitis.
C. Stroke.
D. Surgery.
E. Acute chest syndrome.
B. Given the high risk of complications associated with stroke, pregnancy, and sur-
gery in patients with sickle cell disease, these are the most common situations in
which prophylactic transfusion occurs. Therapeutic indications for red cell transfu-
sion include acute chest syndrome. Transfusion is not a common therapy for osteo-
myelitis in patients with sickle cell disease.
________________________________ ________________________________
夝
Question 16: In the STOP (Stroke Prevention Trial in Sickle Cell Anemia) Trials what
percentage of hemoglobin S was established as a target for prophylaxis of stroke in
sickle cell patients?
A. 10%
B. 30%