2. Basic techniques and prinicples Flashcards
1667
first recorded animal to human blood transfusion by Jean-Baptiste Denis
1818
first human to human blood transfusion by James Blundell
1900
ABO system was identified by Karl Landsteiner
1908
Reuben Ottenburg first described the use of the crossmatch
1910
William Moss wrote first procedures for BB testing
1941
Charles Drew helped establish National Blood Donor Service (WWII)
AABB publishes…
Standards for Blood Banks and Transfusion Services
rules for reading tubes (6)
Standardized light and mirror (optical aid)
Remove no more than 3 tubes at a time
Observe for hemolysis before shaking (clear red background)
Shake tubes to create “swirling” action
Grade when cell button is completely resuspended/breaks off
Reaction grades ≠ interpretations
M+
microscopic agglutination
2+mf
mixed field agglutination
principle of DAT
Detection of in vivo sensitization of RBCs with IgG and/or complement
Part of HTR, HDFN and AIHA investigation
DAT
DAT procedure
Patient cells are washed, treated with polyspecific AHG, and spun
if DAT is +…
perform a monospecific DAT to determine if cells are sensitized with IgG or complement
requires QC with checkcells
any procedure involving AHG
(DAT)
principle of IAT
Detection of in vitro sensitization of RBCs with IgG
Part of ABS (antibody screen), XSM (crossmatch), Ag typing, and titering
IAT
with PEG in IAT, you must use…
anti-IgG AHG
IAT procedure
Patient plasma is added to screen cells I, II and III and incubated at 37° for 15 minutes
then washed, treated with AHG
AGT false positives (8)
Improper specimen
Autoagglutinable cells
Polyagglutinable cells
Bacterial contamination
Overcentrifugation
Overreading
Preservative-dependant Ab
DAT + cells used for IAT (will always be +)
AGT false negatives (7)
Inadequate washing
AHG reagent or serum not added
AHG reagent deteriorated
Inadequate incubation
Weak or heavy cell suspension
Under or overcentrifugation
Poor reading technique
method of choice for ID of Ab after DAT+
acid elution
acid elution procedure
Ab-sensitized RBC in vivo + eluting solution (mix/spin) →
free Ab in acidic supernatant + buffering solution (mix/spin) →
free Ab in neutral supernatant
ensures that Ab in acid elution is from RBC and not free Ab
test with 4th washing
used for forward ABO typing
Anti-A
Anti-B
used for Rh typing
Anti-D
Checks for auto/polyagglutinable cells after A+/B+ result
monoclonal control
used for reverse ABO typing
A1 and B cells
used for detecting unexpected Ab
screen cells (I, II, III)
used to detect IgG-sensitized RBCs
AHG
pretransfusion tests (6)
Type & screen
Crossmatch
DAT
Elution
Ab panel
Ag typing
informational tests (5)
ABO/Rh type
Prenatal screen & type
Cord blood testing
DAT only
Ab titer
clinically significant BG systems (7)
ABO
Rh
Duffy
Kell
Kidd
Ss
Lub
clinically insignificant BG systems (4)
MN
Lewis
Lua
P1
antithetical alleles
antigens represent different forms of a gene produced from the same locus
6-digit number assigned to each BG antigen
ISBT notation
carbohydrate based BG (5)
ABO, Lewis, P, Ii, MNS
protein based BG (4)
Rh, Kidd, Duffy, Lutheran
both carbohydrate and protein BG
Kell
BG enhanced by proteolytic enzymes (6)
Rh, Kidd, Lewis, P, Fy:3, Ii
BG destroyed by proteolytic enzymes (2)
Duffy, MN
BG unaffected by proteolytic enzymes (3)
Kell, SsU, Lutheran
IgM BGs (5)
ABO, Lewis, P1, Mn, Lua
IgG BGs (6)
Rh, Kell, Duffy, Kidd, SsU, Lub
BG usually able to bind complement (3)
ABO, Kidd, Lewis
BG that rarely bind complement (5)
Duffy, P1, Ss, Lutheran, Kell
BG that usually don’t bind complement (1)
Rh
