blood

Question 1

ABO group discrepancies

Answer 1

forward and reverse grouping don’t match

Question 2

Anti-reagent antibody

Answer 2

due to dyes in anti-A or B
Preservatives in reagents
Solve by washing patient/reagent cells

Question 3

B(A) phenotype

Answer 3

high conc of B glycosyltransferase
has weak expression of A on RBCs, anti-A antibodies produced
detected when using MHO4 anti-A monoclonal antibody
solve by using different grouing reagent

Question 4

Acquired B

Answer 4

Group A with gut problems. bacterial remove acetyl group
some anti-B reagent binds to the non-acetyl -> weak pos
solve by using diff reagent or decrease pH

Question 5

Cell problem that result in weak reaction in forward group

Answer 5

B(A): group B, weak A
acquired B: group A, weak (not true) B
Chimerism

Question 6

cisAB

Answer 6

1 allele AB, 1 allele O
decrease glycosyltransferase production -> weak reaction
usually produce weak anti-B
solve by doing family studies

Question 7

Chimerism

Answer 7

2 different population of RBCs in circulation

Question 8

Cause of natural chimerism

Answer 8

multiple births: blood flow b/w twins of diff group
dispermy: 2 sperm, zygote fuse to one
fetal-maternal blood

Question 9

natural chimerism

Answer 9

reaction depends on degree of chimera
solved using history
molecular methods to Id chimera

Question 10

acquired chimerism

Answer 10

out of group transfusions
BM/SC transplant
exchange transfusion ( replace fetal cells w/ donor cells)

Question 11

steps in resolving ABO discrepancies

Answer 11

Re-test
wash cells and re-test
Check history (age, disease state, transfusion)
discrepancies in forward or reverse
know what’s in reagents
test for specific cause

Question 12

type of transplant

Answer 12

Autologous: own cells, disease in remission
Allogeneic: other person, cant donate own cell due to chemo ect.
Syngeneic: identical siblings

Question 13

sources of HPCs

Answer 13

BM
PB
Cord blood

Question 14

sample prep for transplant

Answer 14

flow for CD34 (marker for HPCs)
BM filtered to remove fat, debris
Separate buffy coat

Question 15

Transplanting

Answer 15

recipient marrow/immune ablated
donor cell infused
ABO incompatible OK, HPCs dont express ABO antigen

Question 16

ABO Major mismatch transplants

Answer 16

Foreign antigen of DONOR
HOST produce abys against DONOR

Question 17

ABO Minor mismatch transplants

Answer 17

Foreign abys in DONOR
DONOR produce abys against HOST
passenger lymphocyte syndrome: donor lymphocyte infused into recipient > haemolysis

Question 18

ABO Bi-directional mismatch transplants

Answer 18

major and minor mismatch
e.g. A recipient and B donor

Question 19

Engraftment results

Answer 19

Early (9-30 days): inc neutrophil count
platelet @ 15+ days
RBC @ 90+ days
require support

Question 20

Transfusion support in major mismatch

Answer 20

until abys disappear
RBC given same group as HOST
PLT given same group as DONOR

Question 21

Transfusion support in minor mismatch

Answer 21

until abys disappear
RBC given same group as DONOR
PLT given same group as HOST

Question 22

Transfusion support in bi-directional mismatch

Answer 22

if HOST group A, DONOR group B
RBC group O
PLT AB

Question 23

Transfusion support in organ transplant (ABO compatible)

Answer 23

blood products leukoreduced
no need for irradiation

Question 24

Transfusion support in organ transplant (ABO incompatible)

Answer 24

possible major mismatch
host antibodies reduced by plasmapheresis and immunosuppressed
blood product must me compatible with host and graft for life

Question 25

low frequency antigen

Answer 25

in >10% of population
antibodies are rare, not routinely ID
easy to find blood for transfusion

Question 26

high frequency antigen

Answer 26

in >98% population
antibodies are rare, pos for all panel cell

Question 27

Diego blood group

Answer 27

Di(a+b-) <0.01% in most, 0.1% in south american
di(a-b+) >99% in caucasian, africans americans, less in asain and SA

Question 28

Multiple antibodies

Answer 28

varying strength
pos against many panel cells
pattern of reaction doesn’t match just 1
neg auto control

Question 29

most common antibody combination

Answer 29

C&D 31%
c&E 12%
Lea&Leb 12 (seen in pregnancies)
E&K 8%

Question 30

anti G