A 34-year-old woman with three previous pregnancies received two units of red cells after surgery; her pre-transfusion antibody screen was negative. Seven days later she is jaundiced, her Hb has fallen from 10.4 to 7.6 g/dL, the antibody screen is now positive, the DAT is positive with anti-IgG, and the eluate contains anti-Jka. The most likely explanation is:

An anamnestic anti-Jka causing delayed haemolysis

An ABO-incompatible transfusion error

Passive anti-Jka transfused in donor plasma

Warm autoimmune haemolytic anaemia

Which donor screening method shortens the HIV window period the most?

Fourth-generation antigen-antibody ELISA

Third-generation antibody ELISA

Two hours after FFP from a donor with four previous pregnancies, a patient becomes hypoxic with bilateral lung infiltrates, a normal BNP and no response to diuretics. The usual mechanism is:

Donor anti-HLA or anti-HNA antibodies

Rapid infusion causing fluid overload

Bacterial contamination of the unit

Donors, components and transfusion reactions

44 Kerala MSc MLT Entrance practice questions on Donors, components and transfusion reactions, part of Haematology and Blood Banking. The first 25 are below; the first 5 with answers and explanations (tap Show answer after you have chosen), the rest in Learn with a free account.

Question 1 · Easy
Under NBTC donor selection guidelines, how long must a person wait after getting a tattoo before donating blood?
1. A12 months
2. B24 months
3. C3 months
4. D6 months
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Answer: A · 12 months
Tattooing, body piercing and acupuncture can transmit hepatitis B, hepatitis C and HIV, and an infection picked up during the procedure may still be in its window period when the donor is screened. Indian guidelines therefore defer such donors for 12 months. A negative screening test at the time of donation does not remove the deferral. A similar 12-month deferral applies to a person who has received a blood transfusion.
- B: 24 months is longer than required; the deferral is 12 months.
- C: 3 months is the interval between whole blood donations for men, not the tattoo deferral.
- D: 6 months is shorter than the deferral Indian guidelines set after a tattoo.
Question 2 · Medium
A patient is to receive red cells donated by his own father. Which treatment of the unit protects him from the T-cell complication this raises?
1. ALeucocyte filtration
2. BGamma irradiation
3. CWashing with saline
4. DFreezing in glycerol
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Answer: B · Gamma irradiation
TA-GVHD occurs when viable donor T lymphocytes engraft and attack a recipient who cannot reject them, such as a fetus receiving intrauterine transfusion, a stem cell transplant recipient, or a patient given blood from a first-degree relative. Irradiation, at 25 Gy to the centre of the bag, stops the lymphocytes from dividing. Leucofiltration lowers the lymphocyte count but leaves enough to cause GVHD, so it is no substitute. TA-GVHD is almost always fatal, which is why prevention matters.
- A: Leucofiltration reduces T cells but does not remove enough to prevent GVHD.
- C: Washing removes plasma proteins, not the lymphocytes.
- D: Glycerol freezing is for long-term red cell storage and does not reliably inactivate lymphocytes.
Question 3 · Hard
A 34-year-old woman with three previous pregnancies received two units of red cells after surgery; her pre-transfusion antibody screen was negative. Seven days later she is jaundiced, her Hb has fallen from 10.4 to 7.6 g/dL, the antibody screen is now positive, the DAT is positive with anti-IgG, and the eluate contains anti-Jka. The most likely explanation is:
1. AAn anamnestic anti-Jka causing delayed haemolysis
2. BAn ABO-incompatible transfusion error
3. CPassive anti-Jka transfused in donor plasma
4. DWarm autoimmune haemolytic anaemia
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Answer: A · An anamnestic anti-Jka causing delayed haemolysis
Kidd antibodies often fall below detectable levels after the first exposure, here pregnancy, so the screen can be negative. Transfused Jk(a+) cells trigger a secondary response, and within 3-14 days the new IgG anti-Jka coats and destroys the donor cells, giving a falling Hb, jaundice and a positive DAT. The eluate identifies the antibody, and future units must be Jk(a-) and crossmatched by the antiglobulin method. An ABO error causes haemolysis within minutes to hours, and red cell units carry too little plasma for passive antibody to cause this picture.
- B: ABO incompatibility causes haemolysis within minutes to hours of transfusion.
- C: Red cell units contain too little plasma for passive antibody to cause this.
- D: A warm autoantibody reacts with all cells, not with a specific Kidd antigen.
Question 4 · Easy
Which donor screening method shortens the HIV window period the most?
1. AFourth-generation antigen-antibody ELISA
2. BRapid antibody card test
3. CNucleic acid testing (NAT)
4. DThird-generation antibody ELISA
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Answer: C · Nucleic acid testing (NAT)
NAT detects viral RNA or DNA directly and becomes positive roughly 5-10 days after HIV infection, depending on whether samples are pooled, ahead of p24 antigen and well ahead of antibody. Fourth-generation ELISA detects p24 antigen as well as antibody and shortens the window to about 2-3 weeks. Antibody-only tests leave the longest window. Many Indian blood centres add NAT for HIV, HBV and HCV to the mandatory serological screening.
- A: Fourth-generation ELISA detects p24 antigen but still lags behind NAT.
- B: Rapid card tests detect antibody and are less sensitive than ELISA.
- D: Third-generation ELISA detects antibody only, which appears later.
Question 5 · Medium
Two hours after FFP from a donor with four previous pregnancies, a patient becomes hypoxic with bilateral lung infiltrates, a normal BNP and no response to diuretics. The usual mechanism is:
1. ARecipient anti-IgA antibodies
2. BRapid infusion causing fluid overload
3. CDonor anti-HLA or anti-HNA antibodies
4. DBacterial contamination of the unit
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Answer: C · Donor anti-HLA or anti-HNA antibodies
In TRALI, antibodies in donor plasma, usually against HLA class I or II or human neutrophil antigens, bind the recipient's primed neutrophils, which then damage the lung capillaries. Within 6 hours of transfusion the patient develops hypoxia and bilateral lung infiltrates, often with fever and low blood pressure, but without fluid overload. Donors with several previous pregnancies are the commonest source, so using plasma from male donors has reduced the risk. TACO, in contrast, shows raised blood pressure and BNP and responds to diuretics.
- A: Anti-IgA in an IgA-deficient recipient causes anaphylaxis, not TRALI.
- B: Fluid overload is TACO, which responds to diuretics.
- D: Bacterial contamination causes septic shock with high fever.
Question 6 · Hard
A 1.8 m² adult with aplastic anaemia receives an apheresis platelet unit containing 3 x 10^11 platelets. The count is 10,000/µL before and 20,000/µL one hour after. A 1-hour corrected count increment below 7,500 indicates a poor response. What is the CCI, and what does it show?
1. A3,300: a poor response
2. B12,000: an adequate response
3. C6,000: a poor response
4. D18,000: an adequate response
Answer and explanation in LearnFree account
Question 7 · Medium
Cryoprecipitate, made by thawing FFP at 1-6°C, is a concentrated source of which proteins?
1. AAntithrombin, protein C and protein S
2. BAlbumin and immunoglobulin G
3. CFactors II, VII, IX and X
4. DFibrinogen, factor VIII, VWF and factor XIII
Answer and explanation in LearnFree account
Question 8 · Hard
Twenty minutes into a unit of pooled platelets on its fifth day of storage, a patient's temperature rises from 37.0 to 40.1°C with rigors, and blood pressure falls to 80/50 mm Hg. The plasma is not pink, the DAT is negative, the clerical check is correct, and there is no rash or wheeze. What is the most likely cause?
1. ABacterial contamination of the platelets
2. BFebrile non-haemolytic transfusion reaction
3. CAnaphylaxis from anti-IgA antibodies
4. DAcute haemolytic transfusion reaction
Answer and explanation in LearnFree account
Question 9 · Easy
In CPDA-1, adenine is added to:
1. AHelp red cells keep up their ATP
2. BBuffer the fall in pH
3. CSupply glucose for glycolysis
4. DBind calcium and stop clotting
Answer and explanation in LearnFree account
Question 10 · Medium
Transfusion-transmitted syphilis is rare from red cells that have been in the refrigerator for more than about 3 days, because Treponema pallidum:
1. ADoes not survive storage at 2-6°C for long
2. BIs removed by the additive solution
3. CIs detected early by NAT on every unit
4. DIs destroyed by complement in donor plasma
Answer and explanation in LearnFree account
Question 11 · Hard
During quality control of a random donor platelet concentrate made from 450 mL whole blood, the volume is 55 mL and the platelet count in the bag is 1,200 x 10^3/µL. The centre's standard is at least 5.5 x 10^10 platelets per unit. The platelet yield and verdict are:
1. A6.6 x 10^11, meets the standard
2. B6.6 x 10^9, fails the standard
3. C6.6 x 10^10, fails the standard
4. D6.6 x 10^10, meets the standard
Answer and explanation in LearnFree account
Question 12 · Medium
Red cells frozen with 40% glycerol must be deglycerolised by washing before transfusion, because glycerol left inside the cells would:
1. AInhibit the patient's plasma coagulation factors
2. BProvoke an IgE-mediated allergic reaction
3. CBind the patient's ionised calcium
4. DDraw in water and lyse the cells in the patient
Answer and explanation in LearnFree account
Question 13 · Medium
Halfway through a unit of FFP, a patient develops a few itchy wheals on the arms. Temperature, pulse and blood pressure are unchanged and the chest is clear. The appropriate action is to:
1. AStop and start a full haemolytic reaction workup
2. BStop and send the bag and patient for blood cultures
3. CPause, give an antihistamine and resume if it settles
4. DContinue at a faster rate to finish the unit sooner
Answer and explanation in LearnFree account
Question 14 · Easy
Once a red cell unit has been taken out of controlled storage and spiked for use, the transfusion should be completed within:
1. A4 hours
2. B24 hours
3. C30 minutes
4. D12 hours
Answer and explanation in LearnFree account
Question 15 · Medium
A Rh D-negative 25-year-old woman needs platelets, and only D-positive apheresis units are available. To prevent her forming anti-D, she should be given:
1. AOnly irradiated platelet units
2. BRh immunoglobulin (anti-D)
3. CWashed platelets resuspended in saline
4. DIntravenous immunoglobulin before each dose
Answer and explanation in LearnFree account
Question 16 · Medium
A febrile non-haemolytic transfusion reaction is caused mainly by:
1. ADonor leukocyte cytokines or anti-leukocyte antibodies
2. BRecipient anti-A or anti-B binding donor red cells
3. CEndotoxin from bacteria growing in the unit
4. DRecipient anti-IgA reacting with donor plasma
Answer and explanation in LearnFree account
Question 17 · Hard
Ten minutes into a red cell transfusion, a post-operative patient complains of chills and low back pain. Temperature rises from 37.0 to 38.8°C, blood pressure falls to 90/60 mm Hg, and the urine bag shows red urine. What should the nurse do first?
1. AFinish the unit, then send a sample to the blood bank
2. BStop the transfusion and keep the line open with saline
3. CGive an antihistamine and continue cautiously
4. DSlow the transfusion and give paracetamol
Answer and explanation in LearnFree account
Question 18 · Easy
The citrate in CPDA-1 prevents stored blood from clotting by:
1. ABlocking platelet cyclooxygenase
2. BActivating antithrombin
3. CChelating ionised calcium
4. DRemoving fibrinogen
Answer and explanation in LearnFree account
Question 19 · Easy
Before a whole blood donation, the venepuncture site is usually disinfected with:
1. ASterile normal saline wipes
2. B1% sodium hypochlorite wash
3. CChlorhexidine in isopropyl alcohol
4. D3% hydrogen peroxide swabs
Answer and explanation in LearnFree account
Question 20 · Hard
A 70 kg man with DIC has a fibrinogen of 80 mg/dL and a haematocrit of 30%. The target fibrinogen is 150 mg/dL. Take blood volume as 70 mL/kg and assume each cryoprecipitate bag contains 250 mg of fibrinogen. About how many bags are needed?
1. A21 bags
2. B16 bags
3. C10 bags
4. D14 bags
Answer and explanation in LearnFree account
Question 21 · Medium
A regular plateletpheresis donor mentions that he took aspirin for a headache yesterday. Why must the procedure be deferred?
1. AAspirin irreversibly blocks platelet cyclooxygenase
2. BAspirin lowers the donor's platelet count sharply
3. CAspirin raises the donor's risk of citrate toxicity
4. DAspirin is passed on and harms the recipient
Answer and explanation in LearnFree account
Question 22 · Medium
Granulocyte concentrates collected by apheresis must be:
1. AStored at 2-6°C for up to 5 days
2. BFrozen with glycerol until needed
3. CIrradiated and transfused within 24 hours
4. DLeukoreduced through a bedside filter
Answer and explanation in LearnFree account
Question 23 · Medium
Which organism is classically linked with severe septic reactions from red cell units stored for several weeks at 2-6°C?
1. AStaphylococcus epidermidis
2. BYersinia enterocolitica
3. CBacillus cereus
4. DTreponema pallidum
Answer and explanation in LearnFree account
Question 24 · Medium
In the platelet-rich plasma (PRP) method of preparing random donor platelets, the whole blood unit is centrifuged:
1. AFirst by a light spin, then the PRP by a heavy spin
2. BOnce by a heavy spin to separate all three layers
3. CFirst by a heavy spin, then the buffy coat lightly
4. DFirst by a heavy spin, then the plasma by a heavy spin
Answer and explanation in LearnFree account
Question 25 · Hard
A patient has a reaction during a red cell unit. Results: pre-transfusion sample group O Rh D-positive; post-transfusion sample group O with a mixed-field reaction with anti-A; post-transfusion plasma pink; DAT on the post-transfusion sample positive (mixed-field); the bag is labelled group A Rh D-positive and the crossmatch record shows a different patient's name. The most likely cause is:
1. ANon-immune haemolysis from overheating
2. BBacterial contamination of the red cell unit
3. CWrong unit given due to an identification error
4. DA Kidd antibody missed in the pre-transfusion screen
Answer and explanation in LearnFree account

19 more Donors, components and transfusion reactions questions

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Donors, components and transfusion reactions

Under NBTC donor selection guidelines, how long must a person wait after getting a tattoo before donating blood?

A patient is to receive red cells donated by his own father. Which treatment of the unit protects him from the T-cell complication this raises?

Which donor screening method shortens the HIV window period the most?

Two hours after FFP from a donor with four previous pregnancies, a patient becomes hypoxic with bilateral lung infiltrates, a normal BNP and no response to diuretics. The usual mechanism is:

A 1.8 m² adult with aplastic anaemia receives an apheresis platelet unit containing 3 x 10^11 platelets. The count is 10,000/µL before and 20,000/µL one hour after. A 1-hour corrected count increment below 7,500 indicates a poor response. What is the CCI, and what does it show?

Cryoprecipitate, made by thawing FFP at 1-6°C, is a concentrated source of which proteins?

In CPDA-1, adenine is added to:

Transfusion-transmitted syphilis is rare from red cells that have been in the refrigerator for more than about 3 days, because Treponema pallidum:

During quality control of a random donor platelet concentrate made from 450 mL whole blood, the volume is 55 mL and the platelet count in the bag is 1,200 x 10^3/µL. The centre's standard is at least 5.5 x 10^10 platelets per unit. The platelet yield and verdict are:

Red cells frozen with 40% glycerol must be deglycerolised by washing before transfusion, because glycerol left inside the cells would:

Halfway through a unit of FFP, a patient develops a few itchy wheals on the arms. Temperature, pulse and blood pressure are unchanged and the chest is clear. The appropriate action is to:

Once a red cell unit has been taken out of controlled storage and spiked for use, the transfusion should be completed within:

A Rh D-negative 25-year-old woman needs platelets, and only D-positive apheresis units are available. To prevent her forming anti-D, she should be given:

A febrile non-haemolytic transfusion reaction is caused mainly by:

Ten minutes into a red cell transfusion, a post-operative patient complains of chills and low back pain. Temperature rises from 37.0 to 38.8°C, blood pressure falls to 90/60 mm Hg, and the urine bag shows red urine. What should the nurse do first?

The citrate in CPDA-1 prevents stored blood from clotting by:

Before a whole blood donation, the venepuncture site is usually disinfected with:

A 70 kg man with DIC has a fibrinogen of 80 mg/dL and a haematocrit of 30%. The target fibrinogen is 150 mg/dL. Take blood volume as 70 mL/kg and assume each cryoprecipitate bag contains 250 mg of fibrinogen. About how many bags are needed?

A regular plateletpheresis donor mentions that he took aspirin for a headache yesterday. Why must the procedure be deferred?

Granulocyte concentrates collected by apheresis must be:

Which organism is classically linked with severe septic reactions from red cell units stored for several weeks at 2-6°C?

In the platelet-rich plasma (PRP) method of preparing random donor platelets, the whole blood unit is centrifuged: