Master Blood Transfusion: A Medical Quiz on OmpathStudy

MOUNT KENYA UNIVERSITY — SCHOOL OF MEDICINE Programme: Bachelor of Medicine and Bachelor of Surgery, Year 3 Assessment: Mid Semester 3 — Continuous Assessment Test One Date: May 2026 Unit Code: MBHA 3514B / MBML 3223 Unit Title: Blood Transfusion Medicine Reg No: BMS/2023/.. --- Q1. 35-year-old, 30 min into pRBC transfusion: fever 38.8°C, rigors, flank pain, haemoglobinuria. a. Febrile non-haemolytic reaction b. Acute haemolytic transfusion reaction c. TRALI d. Anaphylactic reaction e. Bacterial contamination Answer: b — Acute haemolytic transfusion reaction Haemoglobinuria + flank pain = intravascular haemolysis, classic for AHTR (usually ABO mismatch). FNHTR lacks haemoglobinuria; TRALI causes respiratory distress, not haemolysis; anaphylaxis lacks fever/haemoglobinuria; bacterial contamination usually shows more severe sepsis picture. Q2. Underlying immune mechanism of acute haemolytic transfusion reaction? a. IgE-mediated mast cell degranulation b. IgG/IgM-mediated complement activation c. Cytotoxic T-cell destruction d. Immune complex deposition in glomeruli e. NK cell activation Answer: b — IgG/IgM-mediated complement activation ABO antibodies (IgM mainly) activate complement → intravascular lysis. IgE (a) is Type I hypersensitivity, not relevant here; T-cells (c) and immune complexes (d) are not the primary mechanism in AHTR. Q3. Which test detects IgG antibodies coating patient red cells? a. Forward grouping b. Reverse grouping c. Direct antiglobulin test (DAT) d. Indirect antiglobulin test (IAT) e. Crossmatch by saline technique Answer: c — Direct antiglobulin test (DAT) DAT detects antibody already bound to the patient's own cells; IAT (d) detects antibody in patient serum reacting with reagent cells; forward/reverse grouping (a,b) determine ABO type, not antibody coating. Q4. Neonate with jaundice/anaemia; mother O Rh-negative, baby O Rh-positive. a. Neonatal alloimmune thrombocytopenia b. Haemolytic disease of the foetus and newborn c. ABO incompatibility causing intravascular haemolysis d. G6PD deficiency e. Hereditary spherocytosis Answer: b — Haemolytic disease of the foetus and newborn Rh-negative mother sensitised against Rh-positive baby's cells → anti-D crosses placenta → haemolysis. Same ABO group (both O) rules out ABO incompatibility (c); a, d, e are unrelated to this Rh mismatch scenario. Q5. Group O Rh-negative patient, haemorrhagic shock, urgent transfusion before crossmatch available — safest choice? a. Group A Rh-positive pRBC b. Group O Rh-positive pRBC c. Group O Rh-negative pRBC d. Group AB Rh-positive whole blood e. Group O Rh-negative whole blood only if crossmatched Answer: c — Group O Rh-negative pRBC Universal donor red cells, safe without crossmatch in emergencies. Others carry ABO/Rh antigens (a,b,d) that could cause reaction; e wrongly requires crossmatch, defeating the emergency purpose. Q6. 50-year-old, dyspnoea + bilateral infiltrates within 6h of transfusion, no fluid overload, SpO2 85%. a. TACO b. TRALI c. Acute haemolytic reaction d. FNHTR e. Allergic/anaphylactic reaction Answer: b — TRALI Acute lung injury within 6h, no volume overload, is the defining feature of TRALI. TACO (a) would show fluid overload signs; c, d, e don't fit this pulmonary/hypoxic presentation. Q7. Unexpected alloantibody found in pre-transfusion testing — which technique confirms specificity? a. Forward ABO grouping b. Antibody panel (antibody identification) c. DAT only d. Platelet crossmatch e. Clot retraction test Answer: b — Antibody panel (antibody identification) A panel of known-antigen reagent cells identifies the specific antibody. Forward grouping (a) only determines ABO type; DAT (c) detects antibody on the patient's own cells, not identify specificity of a free antibody. Q8. Sickle cell patient, long-term transfusion, anaemia despite transfusions, positive DAT. a. Iron deficiency anaemia b. Delayed haemolytic transfusion reaction (DHTR) c. Transfusion-associated GVHD d. Post-transfusion purpura e. Hyperviscosity syndrome Answer: b — Delayed haemolytic transfusion reaction (DHTR) Common in chronically transfused sickle cell patients due to alloimmunisation; positive DAT reflects antibody-coated transfused cells being destroyed. Others don't fit this typical chronic-transfusion complication. Q9. 4-year-old with aplastic anaemia — mandatory processing step to prevent TA-GvHD? a. Leukodepletion b. Irradiation c. Washing d. Cryoprecipitate reduction e. CMV-seronegative selection only Answer: b — Irradiation Irradiation inactivates donor T-lymphocytes, preventing them from engrafting and causing GvHD in immunocompromised recipients. Leukodepletion (a) reduces WBC count but doesn't reliably prevent GvHD; washing (c) and CMV-negative selection (e) address different risks. Q10. Which screening test uses nucleic acid amplification technology (NAT) to close the window period? a. ELISA for HIV antibody b. RPR for syphilis c. NAT for HIV RNA and HCV RNA d. HBsAg ELISA e. Malaria RDT Answer: