ASCP Transfusion Medicine 2

Question 1

The most clinically significant Rh antigen after D is:

Accepted Answer

c antigen (little c)

Answer

The c (little c) antigen is the most clinically significant Rh antigen after D. Anti-c can cause severe hemolytic transfusion reactions and HDFN, and is particularly important in sickle cell disease patients with chronic transfusion needs.

Question 2

Cryoprecipitate is prepared from fresh frozen plasma (FFP) and is enriched for which components?

Accepted Answer

Fibrinogen, Factor VIII, vWF, Factor XIII, and fibronectin

Answer

Cryoprecipitate is the cold-insoluble precipitate formed when FFP is thawed at 1–6 degrees C. It is enriched in fibrinogen (at least 150 mg per unit), Factor VIII (at least 80 IU per unit), vWF, Factor XIII, and fibronectin.

Question 3

Irradiation of blood products prevents:

Accepted Answer

Transfusion-associated graft-versus-host disease (TA-GvHD)

Answer

Blood product irradiation (25 Gy to the center of the unit) inactivates donor T lymphocytes, preventing TA-GvHD in susceptible immunocompromised recipients. TA-GvHD occurs when viable donor T cells engraft and attack the immunocompromised host.

Question 4

Kidd antibodies (anti-Jka, anti-Jkb) are clinically notorious because they:

Accepted Answer

Can become undetectable between transfusions, causing unexpected delayed hemolytic transfusion reactions

Answer

Kidd antibodies are notorious for declining to undetectable levels between transfusions. When antigen-positive blood is transfused, a rapid anamnestic response occurs, causing a delayed hemolytic transfusion reaction (DHTR) 3–14 days later.

Question 5

Which coagulation factor is present in fresh frozen plasma (FFP) but NOT in stored packed red blood cells?

Accepted Answer

Factor VIII

Answer

Factor VIII is labile and rapidly degrades during storage at refrigerated temperatures. FFP stored at minus 18 degrees C or colder preserves Factor VIII. Stored RBC units contain essentially no Factor VIII. FFP contains all coagulation factors including the labile Factors V and VIII.

ASCP Practice Test

ASCP Practice Test

ASCP Transfusion Medicine 2