Martin: Transfusion Medicine Flashcards
RBC membrane contains what?
- Proteins: Rh antigens
- Carbs: ABO system
What are the primary and secondary response to immunization to RBC antigens?
In other words, how do we develop antibodies to antigens that we DON’T have?
1. Primary response: Occurs after 1st immune exposure to a “foreign” protein Ag (days or weeks after exposure)
2. Secondary (anamnestic) response: occurs upon a repeat exposure to a “foreign” protein Ag (noticed much quicker after such exposure); For example, during a transfusion.

For most Blood Group Antigens, but not ABO, what type of AB develop during a primary and secondary response?
- Primary response = a sustained high concentration of IgM + Ab and some IgG after days or weeks
- Secondary response = transient rise in IgM and a sustained IgG

What antigens make up ABO system?
- 1. H
- 2. A
- 3. B
What antigens make up the following blood types:
- O blood
- A blood
- B blood
- AB blood
- 1. O blood = H Ag only
- 2. A blood = H + A
- 3. B blood = H + B
- 4. AB blood = H + (A+B)
What is a secretor, in blood bank terms?
Someone with “Se” allele, which allows them to make ABO antigens in their secretions and plasma.
Roughly 80% of the population carries at least one allele called “Se.”
What is this allele?
“Se” => produces H antigen on “type 1 chains” (long carb-rich chains).
- Once the H antigen is made, then the person can make either A or B antigens (or both) on the type 1 chains
What is the MC type of blood?
Least common?
- Most common: Type O (45%)
- Least common: AB
Antigens & Antibodies in person with Type O blood.
- Antigens = H
- Antibodies =
- Anti-A
- Anti- B
- Anti- AB

Antigens & Antibodies in person with Type A blood.
- Antigens = H + A
- Antibodies = Anti-B

Antigens & Antibodies in person with Type B blood.
- Antigens = H + B
- Antibodies = Anti-A

Antigens & Antibodies in person with Type AB blood.
- Antigens = H/A/B
- Antibodies = None

What are Subtypes of
What are the 2 steps in Blood Typing?
- “Front/forward typing” = determines which antigens are on the patient’s RBC by mixing patients blood with anti-A/B/D antibodies
-
“Back/reverse typing” = test for isohemagglutinins (antibodies against ABO antigens they do NOT have), like Anti-A/anti-B.
- Serum or plasma that was separated from the pts RBC is mixed with two different red cells from the laboratory (A and B cells)
ABO subtypes exist and pose what problem?
Can cause compatability issues when transfusing a patient.
What disease can alter expression of ABO antigens on the RBC?
- 1. Leukemia = ↓ Ag
- 2. “Acquired B” = Intestinal obst → ↑ bowel permeability, bacterial
polysaccharides into circulation abs = orbed by grp A cells
- 2. Gastric or pancreatic cancer = bld grp specific soluble substances (BGSS) in serum neutralizes antisera used in forward grouping.
What is Bombay phenotype?
What is the problem with this phenotype?
- Rare blood type (Oh/ h/h) where patient lacks H antigen. Thus, RBC has NO antigens.
- Antibodies: anti-A, Anti-B, Anti-AB and Anti-H Ab.
- Problem
- Can donate to ANYONE
- Can ONLY receive Bombay blood.
What happens when a patient with Bombay phenotype receives a blood transfusion?
Anti-H IgM Ab (more common than IgG) activates compliment system => intravascular hemolysis of RBC => acute hemolytic transfusion reaction.
What is a complication in mothers with Bombay phenotype?
Hemolytic disease of the newborn can occur (Oh, h/h)
Type O blood can donate blood to who?
All types.

Type A blood can donate blood to who?
- Type A
- Type AB

Type B blood can donate blood to who?
- Type B
- Type AB

Type AB blood can donate blood to who?
- Type AB

What is the Rh (Rhesus) System?
Transmembrane protein antigens on a RBC.
Ab to Rh antigens NOT naturally-occuring antibodies and made d/t exposure of a antigen during pregnancy or transfusion.
5 most important antigens are
- D (Rhesus factor) = Rh+
- “d”= absence of D = Rh-
- C = co-dominant with c
- E = co-dominant with e





