Blood Bank and Transfusion Flashcards

Which test detects weak subgroups of A (A3, Ax) that are missed by routine ABO typing?

Answer: Adsorption-elution technique

Adsorption-elution concentrates anti-A onto cells with very few A antigens, allowing confirmation of weak A subgroups not detected by direct agglutination.

Cold agglutinin disease is most commonly caused by antibodies of which specificity?

Answer: Anti-I

Anti-I is the specificity of the monoclonal IgM cold agglutinin produced in cold agglutinin disease, reacting optimally at 0–4°C.

Which preservative solution allows red blood cells to be stored for up to 42 days?

Answer: AS-1 (Adsol)

Additive solutions such as AS-1 (Adsol) extend RBC shelf life to 42 days by providing extra nutrients for RBC metabolism.

A unit of FFP is thawed at 37°C and must be transfused within:

Answer: 24 hours if kept at 1–6°C

Thawed FFP relabeled as 'thawed plasma' can be stored at 1–6°C for up to 5 days; if used as FFP it should be infused within 24 hours.

The Kidd blood group system is clinically significant primarily because Kidd antibodies:

Answer: Cause dosage and are often transient, leading to delayed hemolytic reactions

Kidd antibodies show dosage, fall below detectable levels quickly, and can cause severe delayed hemolytic transfusion reactions when the antigen is re-encountered.

Which blood component is the treatment of choice for isolated factor VIII deficiency (Hemophilia A)?

Answer: Factor VIII concentrate

Recombinant or plasma-derived Factor VIII concentrate is the preferred treatment for Hemophilia A due to its purity, safety, and precise dosing.

In the indirect antiglobulin test (IAT), what step follows incubation of patient serum with reagent red cells?

Answer: Three washes with saline followed by addition of AHG

Washing three times with saline removes unbound immunoglobulin; residual unbound IgG would neutralize AHG and cause a false-negative result.