26 Transfusion Science Flashcards
characteristics of blood group antibodies (ABO, Rh, & others)
ABO Blood group:
Genes?
Inheritance?
Dominance?
Genes:
- A, B, O alleles
- Inherit one from each parent
- A and B are codominant
characteristics of blood group antibodies (ABO, Rh, & others)
Rh Blood group:
Antigens?
- Proteins on ?
- ? most immunogenic
- Presence of ? on ? = Rh Pos
- Absence of ? on ? = Rh Neg
- ?, and ? also important
- Around ? antigens in system
Rh Blood group:
Antigens?
- Proteins on RBC membrane
- D antigen most immunogenic
- Presence of D on rbc = Rh Pos
- Absence of D on rbc = Rh Neg
- C, c, E, e also important
- Around 50 antigens in system
characteristics of blood group antibodies (ABO, Rh, & others)
ABO Blood group:
Antigens?
Antigens:
- Carbohydrates (oligosaccharides)
- Abundant on red blood cells, epithelial and endothelial cells
- Produce antibodies to antigen they lack unique
Genes:
- A, B, O alleles
- Inherit one from each parent
- A and B are codominant
ABO antibodies:
- Occur ?
- Stimulated by ?
Appear at ?age? // do they change?
Predominantly ?
? significant
Good binders of complement to ?
Cause ?
ABO antibodies:
- Occur naturally
- Stimulated by environment (bacteria, food, or pollen)
Appear at 3-6 months // Remain constant throughout life
Predominantly IgM
Clinically significant
Good binders of complement to C9
Cause Intravascular hemolysis
Complete the table
see image
Discuss acute and delayed hemolytic transfusion reactions to include cause, blood groups involved, symptoms, type of hemolysis, and laboratory indicators
Acute Hemolytic Transfusion Reaction:
- Immediate destruction of donor red cells due to ABO incompatibility // Complement activation causes IVH
- Indicators of IVH: ↑plasma hemoglobin // ↑Lactate dehydrogenase (LD) // ↓haptoglobin (binds free Hb) // Hemoglobinuria
Delayed Hemolytic Transfusion Reaction:
- Donor Red cell destruction caused by IgG antibody formation over time (2-14 days) resulting in EVH
- Blood groups involved in EVH: Rh, Kell, Kidd, Duffy
- Mild (usually not fatal)
- Indicators of EVH: ↓Hb (donor cells destroyed) // ↑Bilirubin (b/d prod of Hb) // ↑LD // Pos Antibody screen // Pos DAT
IVH = Intravascular Hemolysis = Destruction of RBC causing release of free hemoglobin
EVH: Removal of red cells by macrophages in tissues (liver, spleen)
DAT = Detects antibody coating red cells
Discuss hemolytic disease of the fetus and newborn (HDFN) in terms of pathogenesis, treatment, and prevention
Hemolytic Disease of the Fetus and Newborn (HDFN)
- Maternal red cell antibodies (IgG) cross the placenta and attach to fetal cells = hemolysis
- Anemia
- Erythropoiesis “Erythroblastosis fetalis”
- Mild to severe depending on antibody identity and concentration
Discuss hemolytic disease of the fetus and newborn (HDFN) in terms of pathogenesis, treatment, and prevention
In Utero:
- IUT:
In utero tx:
Intrauterine Transfusion (IUT)
- Blood infused through umbilical vein
- >20 weeks gestation
- RBC must be antigen negative to corresponding maternal antibody
- May require multiple transfusions throughout gestation
Discuss hemolytic disease of the fetus and newborn (HDFN) in terms of pathogenesis, treatment, and prevention
Postpartum
Postpartum tx:
Exchange transfusion
- Remove antibody
- Remove sensitized cells
- Remove Bilirubin
- Increase Hemoglobin
Discuss hemolytic disease of the fetus and newborn (HDFN) in terms of pathogenesis, treatment, and prevention
- Screen for ?
- ? at greatest risk
- Provide ? at 28 weeks gestation
- Provide ? postpartum if baby is ?
Hemolytic disease of fetus and newborn prevention
- Screen Pregnant women for RBC antibodies
- Rh Neg women at greatest risk
- Provide Rhlg at 28 weeks gestation
- Provide Rhlg postpartum if baby is Rh Pos
Rhlg : The anti-D immunoglobulin neutralises any RhD positive antigens that may have entered the mother’s blood during pregnancy.
- Human source anti-D
- Attaches to fetal cells (Rh Pos)
- Splenic macrophages remove fetal cells from maternal circulation
- Cleared before immune system recognizes foreign antigen
Hemolytic disease of fetus and newborn (HDFN)
- Foreign antigen stimulus ?
- previous transfusion
- Pregnancy:
1st pregnancy usually unaffected - Rh Neg mothers delivering Rh Pos infants
- Rh D most immunogenic
characteristics of blood group antibodies (ABO, Rh, & others)
Rh Blood group:
Rh Antibodies:
? antibodies
- Form in response to?
Requires what kind of response(s)
? significant
Do not bind ?
Cause ?
Rh Blood group:
Rh Antibodies:
Immune antibodies
- Form in individuals lacking antigen once exposed during transfusion or pregnancy
Requires what kind of response(s)
- Primary and Secondary response needed
Clinically significant
Do not bind complement
Cause extravascular hemolysis
characteristics of blood group antibodies (ABO, Rh, & others)
Other blood groups
-Clinically significant:
- ? antibodies
- ?most common antibody
- React at ?
- Some bind ?
- Cause ?
Examples 4
1. ?: K, k, Kpa, Kpb, Jsa, Jsb
2. ?: Jka, Jkb
3. ?: Fya, Fyb
4. ?: S, s
Other blood groups
-Clinically significant:
- immune antibodies
- IgG
- React at 37°C (warm)
- Some bind complement
- Cause extravascular hemolysis
Examples 4
1. Kell: K, k, Kpa, Kpb, Jsa, Jsb
2. Kidd: Jka, Jkb
3. Duffy: Fya, Fyb
4. MNS: S, s
-Clinically insignificant:
- Naturally occurring antibodies
- IgM
- React below 37°C
- Some bind complement
- Do Not cause hemolysis
Examples 3
1. Lewis: Lea, Leb
2. P: P1
3. MNS: M, N
characteristics of blood group antibodies (ABO, Rh, & others)
Other blood groups
-Clinically insignificant:
- ? antibodies
- ?most common antibody
- React at ?
- Some bind ?
- Cause hemolysis?
Examples 3
1. ?: Lea, Leb
2. ?: P1
3. ?: M, N
Other blood groups
-Clinically insignificant:
- Naturally occurring antibodies
- IgM
- React below 37°C
- Some bind complement
- Do Not cause hemolysis
Examples 3
1. Lewis: Lea, Leb
2. P: P1
3. MNS: M, N
-Clinically significant:
- immune antibodies
- IgG
- React at 37°C (warm)
- Some bind complement
- Cause extravascular hemolysis
Examples 4
1. Kell: K, k, Kpa, Kpb, Jsa, Jsb
2. Kidd: Jka, Jkb
3. Duffy: Fya, Fyb
4. MNS: S, s
A T&S is always performed before blood is given. What is a T&S?
? detects antibodies in patients plasma formed to ? (exmples)
Type and Screen
- ABO Rh
- Antibody screen
Antibody screen detects antibodies in patients plasma formed to blood groups other than ABO (Rh, Kell, Kidd, Duffy etc)
Case study
MF: 24F MVA requires blood transfusion
T&S results for MF:
- ABO Rh: A-
- Ab Screen: neg
What type of blood can she recieve?
What would happen if ABO incompatible blood was given?
? or ? antibodies present in patient plasma bind ? cells and fix ? = ? (IVH)
- Usually caused by ? when collecting sample or infusing blood
Symptoms:
- ?
- ?
- ?
- low ?
- ? tightness
- ? failure
- ?
Can be ? if no intervention
A negative antibody screen result means no RBC antibodies were found
Intravascular hemolysis (IVH):
Anti-A or anti-B antibodies present in patient plasma bind donor cells and fix complement = IVH
What is Acute hemolytic transfusion reaction?
Anti-A or Anti-B antibodies present in patient plasma bind donor cells and fix complement = Intravascular hemolysis (IVH)
- Usually caused by patient misidentification when collecting sample or infusing blood
Symptoms:
- fever
- chills
- hemoglobinuria
- low BP
- Chest tightness
- renal failure
- DIC
Can be fatal if no intervention
What are four indicators of IVH?
- Increased plasma hemoglobin
- decreased haptoglobin (binds free hemoglobin)
- Increased Lactate dehydrogenase (LD)
- Hemoglobinuria
Intravascular hemolysis (IVH):
Anti-A or anti-B antibodies present in patient plasma bind donor cells and fix complement = IVH
If the level of hemoglobin in the blood rises too high, then hemoglobin begins to appear in the urine (hemoglobinuria)
Case study
One week after accident MF moved to ICU; Hemoglobin level is low; developing fever, chills and jaundice
New T&S ordered:
ABO Rh: A neg
Ab Screen: Pos
Why is antibody screen positive?
What could be the identity of the antibody?
One week after accident MF moved to ICU; Hemoglobin level is low; developing fever, chills and jaundice
New T&S ordered:
ABO Rh: A neg
Ab Screen: Pos
Why is antibody screen positive?
- Exposure to foreign antigens on donor red cells can cause immune antibody formation (rbc stimulated)
What could be the identity of the antibody?
- Antibodies to other blood groups (Kell, Kidd, Duffy, Rh antigens other than D
Case study
Anti-K (Kell) was identified in MF’s plasma, and she was crossmatched with two units of A neg K neg blood.
What is causing the fever chills and jaundice?
Delayed hemolytic transfusion reaction
- Antibodies formed to donor antigen upon secondary exposure bind donor cells and are removed in the spleen = extravascular hemolysis
RH, Kell, Kidd, Duffy blood groups involved
Symptoms:
- fever +/- chills
- jaundice
- sometimes asymptomatic
What are five indicators of Delayed hemolytic transfusion reaction (EVH)?
- increased Bilirubin (b/d product of Hb)
- decreased Hb (donor cells are destroyed)
- Increased lactate dehydrogenase (LD)
- Positive antibody screen
- Positive direct antiglobulin test (DAT)
- DAT detects antibody coating red cells
Hb = hemoglobin
