BL - Immunohemotology ABO/Rh Flashcards
Red cells do not carry _____ in humans, and the antigens they do carry are much less polymorphic in the population (that is, many fewer alleles).
MHC antigens
When people repeatedly need ____, which do bear HLA (Class I), they may develop an alloimmunization problem, in which case HLA typing as well becomes necessary.
platelets
_____ are glycolipids found on the surface of all body cells.
Blood group antigens
The ____ spans the plasma membrane, and the terminal sugars confer the antigenic specificity (A, B, or O).
lipid backbone
A set of _____ assemble the basic “core” sugar chain which almost everybody has, called the “H” antigen.
glycosyl transferases
A final glycosyl transferase adds one of three alleles: ____.
A, B, or AB
Type O blood only has the _____ and no working transferase.
basic core H antigen
Red cells do not carry MHC antigens in humans, and the antigens they do carry are much less ____ in the population (that is, many fewer alleles).
polymorphic
Blood group antigens are _____ found on the surface of all body cells.
glycolipids
When people repeatedly need platelets, which do bear HLA (Class I), they may develop an ______ problem, in which case HLA typing as well becomes necessary.
alloimmunization
The lipid backbone spans the plasma membrane, and the ____ confer the antigenic specificity (A, B, or O).
terminal sugars
A set of glycosyl transferases assemble the basic “core” sugar chain which almost everybody has, called the _____.
H antigen
____ only has the basic core H antigen and no working transferase.
Type O blood
_____ blood have a glycosyl transferase allele which puts an additional different sugar on the H antigen.
Group A and B
What is the Bombay phenotype?
blood type without the H antigen, so all other blood including O is foreign
What Abs does type A blood carry?
anti B
What Abs does type O blood carry?
anti A and anti B
What are antibodies to blood antigens called?
isohemagglutinins
What class of antibody are isohemagglutinins?
IgM
What Abs does type AB blood carry?
none
What is the Rh system?
proteins coding for the D/d loci; positive = D positive. Make Ab to it if you are Rh(-) and receive (+) cells
What is a major crossmatch?
Abs in the recipient’s plasma that can cross-react to the donor’s RBCs
What happens in a major crossmatch reaction?
complement-mediated hemolysis, free hemoglobin deposition in the kidneys, and renal failure
What is the crossmatch test?
plasma from recipient is mixed with RBCs from donor- look for hemolysis or agglutination. Positive test = not a match; negative test = compatible
What is the antiglobulin (Coombs) test?
Ab against human Ig to detect human Ig on the surface of RBCs (direct) or plasma (indirect)
What is hemolytic disease of the newborn?
when Rh(+) babies are born to Rh(-) mothers; mom exposed and makes Abs during first pregnancy, so during 2nd pregnancy mom’s Abs cross the placenta and destroy the fetus’ RBCs
What are the s/s of hemolytic disease of the newborn?
jaundice, cerebral palsy, death
How is hemolytic disease of the newborn prevented?
RhoGAM shots to mom after first baby
What is another name for hemolytic disease of the newborn?
erythroblastosis fetalis
Why don’t mom’s isohemagglutinins attack the fetus’ RBCs, no matter the blood type?
they’re IgM and cannot cross the placenta
What are heterophile Abs?
Abs to one antigen that bind to another; cross-reactive Abs
Give an example of a heterophile Ab.
Ab in pts with mono also reacts to horse RBCs; Ab in pts with Syphillis react to the bacterium Treponema pallidum and beef heart
