TRANSFUSION BIOLOGY Flashcards
What is the primary characteristic of a febrile nonhemolytic transfusion reaction (FNHTR)?
A) Rash and itching
B) Hypotension and shock
C) Chills, rigors, and a ≥1°C rise in body temperature
D) Dyspnea and chest pain
Answer: C) Chills, rigors, and a ≥1°C rise in body temperature
Rationale: FNHTR is characterized by chills, rigors, and a rise in body temperature of ≥1°C, as described in the passage.
What is a major cause of FNHTR during the transfusion of cellular blood components?
A) Hemolysis of red blood cells
B) Proinflammatory cytokines in the blood component
C) Bacterial contamination of the transfused product
D) Allergic reaction to plasma proteins
Answer: B) Proinflammatory cytokines in the blood component
Rationale: FNHTR is caused by proinflammatory cytokines in the blood component or recipient antibodies against donor cell antigens.
Which of the following strategies is most effective in preventing FNHTR?
A) Premedication with antipyretics
B) Use of leukocyte reduction, especially prestorage
C) Warming the blood component before transfusion
D) Administering antihistamines before transfusion
Answer: B) Use of leukocyte reduction, especially prestorage
Rationale: Prestorage leukocyte reduction is an effective strategy to prevent FNHTR, as noted in the text.
What is the primary cause of allergic reactions associated with transfusion?
A) Bacterial contamination
B) Plasma proteins in transfused components
C) Proinflammatory cytokines
D) Hemolysis of red blood cells
Answer: B) Plasma proteins in transfused components
Rationale: The text states that allergic reactions are related to plasma proteins present in transfused components.
What is the recommended treatment for an anaphylactic reaction during transfusion?
A) Administer antihistamines and continue the transfusion.
B) Stop the transfusion, maintain vascular access, and administer adrenaline.
C) Restart the transfusion after symptoms resolve.
D) Provide fluids to manage hypotension.
Answer: B) Stop the transfusion, maintain vascular access, and administer adrenaline.
Rationale: An anaphylactic reaction requires stopping the transfusion, maintaining vascular access, and giving adrenaline, as well as other supportive measures like steroids or bronchodilators.
Which group of patients is at risk of anaphylactic reactions due to plasma transfusion?
A) Patients with severe thrombocytopenia
B) Patients with IgA deficiency
C) Patients with preexisting liver disease
D) Patients undergoing chemotherapy
Answer: B) Patients with IgA deficiency
Rationale: The text explains that individuals with IgA deficiency may be sensitized to IgA and are at risk of anaphylactic reactions when receiving plasma.
What precaution is recommended for patients with severe IgA deficiency requiring transfusion?
A) Use irradiated blood components.
B) Premedicate with steroids and antihistamines.
C) Provide IgA-deficient plasma and washed blood components.
D) Avoid transfusions altogether.
Answer: C) Provide IgA-deficient plasma and washed blood components.
Rationale: For IgA-deficient patients, IgA-deficient plasma and washed blood components are recommended to prevent allergic reactions.
What mediates transfusion-related GVHD in affected patients?
A) Engrafted donor T lymphocytes
B) Donor plasma proteins
C) Proinflammatory cytokines
D) Preformed antibodies
Answer: A) Engrafted donor T lymphocytes
Rationale: Transfusion-related GVHD is mediated by engrafted donor T lymphocytes that interact with host HLA antigens.
Which group of patients is at the highest risk of developing transfusion-related GVHD?
A) Patients with IgA deficiency
B) Severely immunosuppressed patients or those homozygous for an HLA haplotype shared with the donor
C) Patients receiving irradiated blood components
D) Patients undergoing chemotherapy for solid tumors
Answer: B) Severely immunosuppressed patients or those homozygous for an HLA haplotype shared with the donor
Rationale: The text highlights these groups as being at high risk due to their inability to reject donor T lymphocytes.
What are the clinical manifestations of transfusion-related GVHD, typically occurring 5–10 days after transfusion?
A) Fever, cytopenia, skin rash, diarrhea, and liver dysfunction
B) Fever, chills, and respiratory distress
C) Rash, pruritus, and urticaria
D) Hypotension, shock, and hemolysis
Answer: A) Fever, cytopenia, skin rash, diarrhea, and liver dysfunction
Rationale: These are the hallmark clinical features of transfusion-related GVHD described in the text.
What is the prognosis for transfusion-related GVHD?
A) Generally good with immunosuppressive therapies
B) Fatal in >90% of cases despite treatment
C) Self-limiting and resolves within days
D) Requires antibiotics and supportive care
Answer: B) Fatal in >90% of cases despite treatment
Rationale: Transfusion-related GVHD is highly resistant to treatment and is fatal in most cases.
What preventive strategy is used to avoid transfusion-related GVHD in at-risk patients?
A) Leukocyte reduction of blood components
B) Administration of antithymocyte globulin before transfusion
C) Irradiation of cellular blood components with a minimum of 25 Gy
D) Premedication with antihistamines and steroids
Answer: C) Irradiation of cellular blood components with a minimum of 25 Gy
Rationale: Irradiation of blood components is the primary prevention method for transfusion-related GVHD.
What is the primary clinical manifestation of TRALI?
A) Rash and fever
B) Hypoxia and noncardiogenic pulmonary edema
C) Circulatory overload and hypotension
D) Hemolysis and jaundice
Answer: B) Hypoxia and noncardiogenic pulmonary edema
Rationale: TRALI is characterized by hypoxia and noncardiogenic pulmonary edema with bilateral interstitial infiltrates on chest x-ray.
When does TRALI typically occur in relation to transfusion?
A) 12–24 hours after transfusion
B) During or within 6 hours of transfusion, but delayed cases may occur up to 72 hours later
C) 24–48 hours after transfusion
D) Only before the transfusion is completed
Answer: B) During or within 6 hours of transfusion, but delayed cases may occur up to 72 hours later
Rationale: TRALI typically occurs during or shortly after transfusion but can occasionally present up to 72 hours later.
Which antibodies in donor plasma are most commonly implicated in TRALI?
A) Anti-IgA antibodies
B) Anti-HLA class II antibodies
C) Anti-RBC antibodies
D) Anti-HLA class I and anti-HNA antibodies
Answer: B) Anti-HLA class II antibodies
Rationale: TRALI often results from the transfusion of donor plasma containing high-titer anti-HLA class II antibodies that bind recipient antigens.
What is the primary treatment for TRALI?
A) Corticosteroids and immunoglobulins
B) Antibiotics and antivirals
C) Supportive care only
D) Plasma exchange
Answer: C) Supportive care only
Rationale: There is no specific treatment for TRALI; management is supportive.
Which recipient factors are associated with an increased risk of TRALI?
A) Chronic hypertension and anemia
B) Smoking, chronic alcohol use, and mechanical ventilation
C) History of allergic reactions to transfusions
D) Autoimmune diseases such as lupus
Answer: B) Smoking, chronic alcohol use, and mechanical ventilation
Rationale: Smoking, chronic alcohol use, shock, liver surgery, cancer surgery, mechanical ventilation, and positive fluid balance are risk factors for TRALI.
Which of the following is NOT a risk factor for TACO?
A) Renal failure
B) Cardiac dysfunction
C) Fever
D) Older age
Answer: C) Fever
Rationale: Fever may be present in TACO, but it is not a risk factor. Key risk factors include renal failure, cardiac dysfunction, older age, and fluid overload.
What is the most appropriate transfusion rate to prevent TACO in at-risk patients?
A) 1 RBCC over 30–60 minutes
B) 1 RBCC over 1–2 hours
C) 1 RBCC over 3–4 hours
D) 1 RBCC over 6 hours
Answer: C) 1 RBCC over 3–4 hours
Rationale: A slow transfusion rate, such as 1 RBCC over 3–4 hours, is recommended to prevent TACO in at-risk patients.
What clinical features are characteristic of TACO?
A) Fever, hypotension, and hemolysis
B) Dyspnea, hypoxia, and systolic hypertension
C) Noncardiogenic pulmonary edema and hypotension
D) Severe thrombocytopenia and bleeding
Answer: B) Dyspnea, hypoxia, and systolic hypertension
Rationale: TACO commonly presents with dyspnea, hypoxia, systolic hypertension, and bilateral infiltrates on chest x-ray.
Which laboratory or imaging finding supports a diagnosis of TACO?
A) Elevated brain natriuretic peptide (BNP)
B) Positive direct antiglobulin test (DAT)
C) Low platelet count
D) Elevated ferritin levels
Answer: A) Elevated brain natriuretic peptide (BNP)
Rationale: Elevated BNP, reflecting fluid overload and cardiac strain, supports the diagnosis of TACO.
What is the primary treatment for TACO once it occurs?
A) Administer antihistamines and steroids
B) Administer oxygen and diuretics
C) Administer adrenaline and stop the transfusion
D) Perform plasma exchange
Answer: B) Administer oxygen and diuretics
Rationale: Treatment for TACO involves stopping the transfusion, administering oxygen to relieve hypoxia, and using diuretics to reduce fluid overload.
Massive transfusion is defined as:
A) Transfusion of 25% of total blood volume over 3 hours
B) Transfusion of 50% of total blood volume over 3 hours or >5–10 RBCC units
C) Transfusion of 75% of total blood volume in 24 hours
D) Transfusion of 100% of total blood volume over 12 hours
Answer: B) Transfusion of 50% of total blood volume over 3 hours or >5–10 RBCC units
Rationale: Massive transfusion is defined as the transfusion of 50% of the patient’s total blood volume over 3 hours or >5–10 units of RBCCs.
What complication can occur due to citrate in transfused blood products?
A) Hyperkalemia
B) Hypocalcemia
C) Hypoglycemia
D) Metabolic alkalosis
Answer: B) Hypocalcemia
Rationale: Citrate chelates calcium, leading to hypocalcemia, which can manifest as circumoral paresthesia and changes in cardiac function.
Which of the following is NOT a typical complication associated with massive transfusion?
A) Citrate toxicity
B) Hyperkalemia
C) Hypothermia
D) Leukocyte refractoriness
Answer: D) Leukocyte refractoriness
Rationale: Leukocyte refractoriness is associated with alloimmunization, not massive transfusion. Massive transfusion complications include citrate toxicity, hyperkalemia, hypothermia, and dilutional coagulopathy.
What is the primary prevention method for hypothermia during rapid blood transfusion?
A) Administering calcium gluconate
B) Using an inline blood warmer
C) Transfusing blood stored for <7 days
D) Washing red blood cells before transfusion
Answer: B) Using an inline blood warmer
Rationale: Using an inline blood warmer prevents hypothermia and cardiac dysrhythmias caused by transfusion of cold blood products.
Which group is at the highest risk of developing hyperkalemia due to massive transfusion?
A) Patients with hypercalcemia
B) Patients with chronic anemia
C) Neonates and patients with renal failure
D) Patients with hypoglycemia
Answer: C) Neonates and patients with renal failure
Rationale: Neonates and patients with renal failure are at increased risk of hyperkalemia due to potassium accumulation from stored RBC leakage.
A patient undergoing massive transfusion develops cardiac dysrhythmias due to hypocalcemia. What is the best treatment?
A) Administer potassium chloride
B) Administer calcium gluconate through a separate line
C) Stop the transfusion and start antihistamines
D) Initiate insulin and glucose therapy
Answer: B) Administer calcium gluconate through a separate line
Rationale: Hypocalcemia caused by citrate toxicity should be managed with calcium infusion through a separate line.
How much iron is typically contained in one unit of RBCs?
A) 100–150 mg
B) 200–250 mg
C) 300–350 mg
D) 400–450 mg
Answer: B) 200–250 mg
Rationale: Each unit of RBCs contains 200–250 mg of iron, which can lead to iron overload in frequently transfused recipients.
Which of the following is NOT a method to assess iron overload?
A) Serum ferritin measurements
B) Magnetic resonance imaging (MRI)
C) Liver biopsy
D) Echocardiography
Answer: D) Echocardiography
Rationale: Iron overload is assessed using serum ferritin, MRI, and liver biopsy. Echocardiography is not a diagnostic tool for iron overload but may assess cardiac complications resulting from it.
What is the primary treatment for transfusion-associated iron overload?
A) Bloodletting
B) Iron supplementation
C) Iron chelation therapy
D) Use of irradiated blood products
Answer: C) Iron chelation therapy
Rationale: Iron chelation therapy, along with careful monitoring, is used to manage iron overload in frequently transfused recipients.
Acute hypotensive transfusion reactions are characterized by:
A) Gradual drop in blood pressure that resolves without intervention
B) Abrupt drop in blood pressure of >30 mmHg resolving quickly after stopping transfusion
C) Severe hypertension requiring immediate medical attention
D) Persistent hypotension requiring vasopressor support
Answer: B) Abrupt drop in blood pressure of >30 mmHg resolving quickly after stopping transfusion
Rationale: Acute hypotensive reactions involve a sudden drop in blood pressure early in the transfusion and resolve quickly after stopping the transfusion.
Which group is most at risk for acute hypotensive transfusion reactions?
A) Patients with untreated anemia
B) Patients taking ACE inhibitors
C) Patients with chronic renal failure
D) Neonates receiving RBC transfusions
Answer: B) Patients taking ACE inhibitors
Rationale: ACE inhibitors reduce the metabolism of bradykinin, increasing the risk of acute hypotensive transfusion reactions.
What is the recommended action after a hypotensive transfusion reaction resolves?
A) Restart the same blood product immediately
B) Restart the same blood product after a 30-minute observation
C) Do not restart the same blood product
D) Administer vasopressors and restart the transfusion
Answer: C) Do not restart the same blood product
Rationale: Once a hypotensive transfusion reaction resolves, the same blood product should not be restarted.
Which rare neurologic syndrome has been described within 10 days of RBCC transfusion in patients with severe anemia?
A) Guillain-Barré syndrome
B) Posterior reversible encephalopathy syndrome (PRES)
C) Wernicke’s encephalopathy
D) Acute disseminated encephalomyelitis
Answer: B) Posterior reversible encephalopathy syndrome (PRES)
Rationale: PRES is a rare syndrome characterized by acute reversible neurologic symptoms related to subcortical vasogenic brain edema, described within 10 days of transfusion in patients with severe anemia.
