ABO/Rh Flashcards
most important antigen group for transfusion and transplant
ABO Blood group
exception when there won’t be rejection
incompatible bone marrow with high immunosuppressive drugs
forward grouping
detect ABO antigen on patient RBCs
reverse grouping
detect ABO antibodies in patient serum
if back typing weak
add additional patient serum and incubate longer at RT
abo antibodies are
naturally occuring
anti-A and anti-B class
IgM
ABO antibodies detectable
3-6 months are birth
Anti-A,B occur naturally in
group O
anti-A, B
predominantly IgG
abo locus
chromsome 9
fucosyltransferase
produces H antigen to type 2 precursor chains
FUT2 produces
soluble H antigen will end up in secretions and body fluids and fixes fucose to type 1 precursor
type 1
B 1-3
type 2
b 1-4
A
N-acetylgalactosaminyl transferase
B
galactosaminyl transferase
AB
N-acetylgalactosaminyl transferase and galactoasminyl transferase
most amount of H
A2
ABH expression complete at
2-4 age
ABH antigens in
body fluids and secretions (secretor trait)
FUT2 modifies type 1 precursor chains to form
soluble H antigen
non secretor
Le a
secretor
Le b
agglutinate with A1
dolichos biflorus
agglutinates cells with H antigen
ulex europaeus
bandeiraea simplicifolia
agglutinated cells with B antigen
produce less antigen
A2
subgroups of A
very weak front typing with anti-A or unexpected A cells in back typing
if suspect an A2 use
A1 lectin and will show no reactivity
B3 is most common subgroup of B
shows mixed field agglutination
hh genotype caused by
lack of H, lack fucosyltransferase = no ABO genes
bombay can only receive
bombay
parabombay
-H expression is near 0
dysfunctional FUT1 with functional FUT2
dysfunctional FUT1 with functional FUT2
very small A, B, H; makes anti-H unless AHG phase
dysfunctional FUT but no FUT2
very small amounts of ABH on RBCs, none in secretions
silenced FUT1 active FUT2
make soluble ABH antigens ; make anti- IH
2nd most important blood group following ABO
Rh system
Rh reside of
proteins
Rh antigens are
not naturally occuring; require foreign RBC’s
Rh null
no Rh antigens (-1,-2,-3,-4,-5)
f antigen
present on cells for homozygous for ce
G antigen
present on all C positive and many D positive cells
Cw antithetical to
near universal antigen MAR
partial D/ mosaic D
-missing or incomplete epitopes for D antigen
-these people can make anti-D against missing portions of antigen so = Rh -
weak d
express d weakling but it still there so Rh +
positional effect C: D
D antigen is complete just reduced, so receive D + units
Rh antibodies class
IgG
Rh donors
weak d testing done on every unit, but be done all the way through
Rh patients
if typed initially as weak d, DO NOT have to follow all the way through
delayed hemolytic transfusion reactions
caused by giving a patient a unit of blood that is positive for an antigen and they have an anamnestic response to that antigen (extravascular lyse)
HDFN
severve from Rh antibody
Rh antigens well developed on fetal cells and cross placenta
rhogam given to what type mother
negative
Rh deficiency syndrome
lack all Rh proteins on RBCs
regulator type
RhAG required to traffic RhD and RhCE to cell surface
RhAG mutated- none produced
amorphic type
mutation in RhCE and deletion of RhD in lack of Rh proteins
symptoms of Rh def
hemolytic anemia, decrease serum haptoglobin, slight elevation in bili
Rh null patients can develop
anti-Rh29 “total Rh” reacts will all Rh antigens
Rh Mod
partial suppression of Rh genes caused by mutations in RhAG protein