MLT GlobeBlood Banking: Transfusion reactions
51 Blood Banking MCQs on Transfusion reactions with answers and explanations.
A transfusion recipient has an alloantibody against an antigen on the donor's red cells. Which reaction is this most likely to cause?
Antibodies to red cell antigens destroy donor red cells, causing hemolysis. Febrile reactions relate to leukocytes/cytokines, post-transfusion purpura to anti-HPA-1a, and TRALI to anti-HLA/HNA antibodies.
Which transfusion complication usually appears weeks to months after transfusion?
Viral hepatitis has an incubation period of weeks to months. Septic reactions, urticaria and TACO appear during or within hours of transfusion.
A patient develops fever, chills and back pain 10 minutes into a red cell transfusion. The FIRST action is to:
Stop the transfusion at once, keep venous access with saline, check the patient and unit identification, and send post-transfusion samples and the bag to the blood bank for a DAT and repeat typing.
What is the most common cause of fatal acute hemolytic transfusion reactions?
Most fatal acute hemolytic reactions are ABO incompatibilities caused by clerical errors, such as a wrong patient or mislabelled sample. Missed weak antibodies usually cause delayed reactions instead.
A patient with thalassemia major receives regular red cell transfusions. Which long-term complication is monitored with serum ferritin?
Each red cell unit contains about 200–250 mg of iron, which the body cannot excrete. Ferritin is used to monitor iron load and guide chelation therapy.
Which measure best reduces the risk of TACO in an elderly patient with poor cardiac function?
Slow infusion and giving single units with reassessment limit volume load; diuretics can also help. Male-donor plasma reduces TRALI, not TACO.
Which mechanism explains the severity of an ABO-incompatible acute hemolytic reaction?
Anti-A and anti-B are mainly IgM and activate complement through C9, lysing cells in the circulation. This can lead to shock, DIC and acute kidney injury.
During rapid infusion of several cold red cell units through a central line, a patient develops a cardiac arrhythmia. The most likely cause is:
Rapid infusion of cold blood can cool the heart and cause arrhythmias. An approved blood warmer should be used for rapid or large-volume transfusion.
Acute transfusion reactions are those that occur within:
Reactions within 24 hours are called acute. Those appearing later (such as delayed hemolysis or TA-GVHD) are called delayed.
Systematic monitoring and reporting of adverse events linked to transfusion is called:
Hemovigilance covers the whole transfusion chain, from donor to recipient, to find and prevent adverse events. Look-back is tracing earlier recipients of a donor later found infected.
After a suspected transfusion reaction, which items should be sent to the blood bank?
The bag and set allow rechecking and culture of the unit, and the post-transfusion sample is used for clerical checks, hemolysis check, DAT and repeat grouping.
Febrile non-hemolytic transfusion reactions are best reduced by using:
Most febrile reactions are caused by donor white cells or the cytokines they release during storage. Leukoreduction before storage greatly reduces them, while irradiation does not.
Transfusion-associated circulatory overload (TACO) is usually managed by:
TACO is fluid overload, so management is to stop the transfusion, sit the patient upright, give oxygen and give diuretics as needed.
Transfusion-associated graft-versus-host disease is caused by:
Viable donor T cells engraft and attack recipient tissues, including the marrow. Irradiating cellular components prevents it.
Which is an infectious complication of transfusion?
Hepatitis C is a transfusion-transmitted infection, which donor screening aims to prevent. The other options are non-infectious reactions.
Which urine finding is a hallmark of an acute intravascular haemolytic transfusion reaction?
Intravascular lysis releases free haemoglobin that saturates haptoglobin and spills into the urine, giving red-brown urine. Unconjugated bilirubin rises in serum but does not appear in urine.
About a week after a transfusion, a patient previously pregnant develops falling haemoglobin, jaundice and a positive DAT. This is best explained by:
Re-exposure to an antigen boosts a previously undetectable IgG alloantibody (e.g., Kidd) 3–14 days later, causing extravascular haemolysis. The other reactions occur within hours.
In the oliguric phase following a severe haemolytic transfusion reaction, which laboratory pattern is expected?
Acute kidney injury from haemoglobin, hypotension and DIC causes retention of urea, creatinine and potassium.
Acute hypoxemia with bilateral lung infiltrates within 6 hours of plasma transfusion, without volume overload, suggests:
TRALI is usually caused by donor anti-HLA or anti-HNA antibodies that activate recipient neutrophils in the lung. Unlike TACO, there are no signs of fluid overload such as raised BNP or response to diuretics.
Anaphylaxis during transfusion in a patient with IgA deficiency and anti-IgA is best prevented in future by giving:
The reaction is caused by the patient's anti-IgA binding donor plasma IgA. Washing removes plasma; plasma products must come from IgA-deficient donors. Irradiation and leukoreduction do not help.