Immunohematology Flashcards
(25 cards)
A type Blood:
1) Red cell antigen
2) ABO Ab in plasma
3) Safe donors
4) Safe recipients
5) Possible Genotypes
6) Most/least common group
1) A sugar + H
2) anti-B
3) A, O
4) A, AB
5) AA, AO
6) White, black, Peru Indians
B type Blood:
1) Red cell antigen
2) ABO Ab in plasma
3) Safe donors
4) Safe recipients
5) Possible Genotypes
6) Most/least common group
1) B sugar + H
2) anti-A
3) B, O
4) B, AB
5) BB, BO
6) Vietnam + central Asia
AB type Blood:
1) Red cell antigen
2) ABO Ab in plasma
3) Safe donors
4) Safe recipients
5) Possible Genotypes
6) Most/least common group
1) A sugar + B sugar + H
2) none
3) A, B, O
4) AB
5) AB
6) 3% white, 4% black
O type Blood
1) Red cell antigen
2) ABO Ab in plasma
3) Safe donors
4) Safe recipients
5) Possible Genotypes
6) Most/least common group
1) H
2) anti-A + anti-B
3) O
4) A, B, AB
5) OO
6) white, black, rare China
Name the antibody class of most ABO isohemagglutinins
IgM (10 heavy, 10 light, 1 light)
Antibodies in Bombay blood type
anti-A
anti-B
anti-H
What happens if you transfuse non-Bombay blood into Bombay patient?
Immune response
Blood group antigens are ____
glycolipids (lipid backbone spans plasma membrane and terminal sugars = antigenic specificy)
What are isohemagglutinins?
Naturally occurring antibodies
during infancy, you come in contact with blood group antigens (glycolipids) and create antibodies
What does Bombay appear as during routine typing?
O blood
but you have anti-A, B, O
What happens in Bombay phenotype?
Pt lacks transferase gene to put final sugar on “core”
Therefore, don’t express H antigen (that O people express)
Define the cross match
plasma from recipient is mixed with RBCs of donor
Why is cross match important?
1) Before transfusion, the recipient typed for ABO and Rh and plasma screened for antibodies
MUST BE IDENTICAL
2) If antibodies in recipient’s plasma that react with donor RBC, RBC die early and patient may die
What happens during mismatch transfusion?
If agglutinate, recipient has IgM + (maybe IgG) activate complement
If no agglutinate, may still be antibody just not enough to agglutinate but can still opsonize/lyse
What is Direct anti globulin test?
is there antibody already on the red cells I am interested in?
1) Take Patient RBCs
2) Rinse them
3) Add anti globulin
4) Detect cells coated with antibody in vivo
–> detects AIHA
What is indirect anti globulin test
is there unexpected antibody to red cell antigens in the PLASMA of recipient
1) Take RBCs from donor
2) add plasma from recipient
3) rinse cells
4) add anti globulin
If agglutinate, MUST BE antibody in plamsa
–> detect transfusion compatability
Define heterophile antibody
Antibodies to 1 antigen which bind to another (cross-reactive).
What is a disease with increased heterophile antibody?
Infectious mono
–> antibody against virus also reacts with sheep RBC
Syphilis
–> antibody cross reacts with phospholipids in beef heart
In hemolytic disease of newborn,
what are consequences?
Fetus born jaundice
High levels of bill (breakdown Hb) cross BBB, damage basal ganglia (cerebral palsy)
In hemolytic disease of newborn, how can mother be sensitized?
Erythroblastosis fetalis
Occurs in Rh(D)+ children of Rh(D)- mothers
If during last trimester and during delivery, some red cells from baby enter mom’s circulation.
If mother is Rh(D)- may make anti-Rh(D) after exposure - not affect first child
In hemolytic disease of newborn, what is class of antibody to Rh(D) mother makes?
Because antibodies can cross placenta, IgG
In hemolytic disease of newborn, consequences of sensitization to subsequent fetuses?
Next pregnancy with Rh(D)+, mom’s antibodies after first prego cross placenta and destroy fetus’ RBC
Each pregnancy with Rh(D)+ boosts mother’s antibody level
In hemolytic disease of newborn, What is role of Rh- immune globulin (RHOGAM)?
1) when mom delivers first Rh(D)+ baby, she is given IgG antibody to Rh(D) (Rh- immune globulin)
2) Antibodies combine with left over fetal RBC, opsonize and destroy before can immunize mom
3) Must receive each time b/c chance of being immunized by Rh(D)+
4) women given RHOGAM shot at 28 weeks and if baby comes out Rh(D)+ another shot given
How can ABO hemolytic disease of newborn can occur?
when women make IgG isohemagglutins (antibodies against B blood that are IgG and can cross placenta)
common in group O
no RHOGAM
