Serologic Testing Flashcards
Pre-transfusion testing - Autologous Donation
ABO
Rh
Pre-transfusion testing of Allogenic Transfusion
ABO, Rh
Antibody Screen
Crossmatching
Serum within 3 days
Specimen for pre-transfusion testing procedures
7 days
Retain patient specimen and segment after transfusion
Universal Donor RBCs
Type O
Universal Recipient RBCs
Type AB
Universal Plasma Donor
Type AB
Universal Plasma Recipinet
Type O
Current mandated test for Pretransfusion sample - ABO
* Forward
* Reverse
Current mandated test for Pretransfusion sample - ABO
* Forward - Anti-A, Anti-B
* Reverse - A1 and B cell
DAT/Direct Coomb’s Test
Direct Antiglobulin Test
Detect clinical conditions due to IN VIVO sensitization of RBCs
HTR, HDFN, AIHA, DIHA
DAT Specimen
EDTA
avoid in viotro activation of C’
IAT/Indirect Coomb’s Test
Detect IN VITRO sensitization of RBCs used in various serologic tests
Antibody screening, Antibody identification, Weak D testing, Crossmatch
IAT Specimen
Serum
Composition of Polyspecific AHG
Green in color
Anti-IgG
Anti-C3d
Ant-kappa and lambda chains (IgG, IgM)
Anti-C3b, Anti-C4b, Anti-C4d
Composition Monospecific AHG
Colorless
Either Anti-IgG or Anti-C3d
AHG Sources of Error - False Positive
AHG Sources of Error - False Positive
* Improper Specimen - Refrigerated/Clotted/Used Serum (DAT)
* Cold autoantibody
* Bacterial contamination
* Overcentrifugation
AHG Sources of Error - False Negative
common are technical probelms
AHG Sources of Error - False Negative
- Inadequate washing
- Fail to add AHG
- Neutralization of AHG
- Prozone/Prozone phenomenon
Check cells/Coomb’s cells
detect if added and with reactive AHG and adequate washing
Check Cell Interpretation
* (+) Agglutination
* (-) No agglutination
Check Cell Interpretation
* (+) Agglutination - FREE AHG (AHG is added & reactive)
* (-) No agglutination - nonreactive AHG, NSS, fail to add AHG
Final Check for Compatibility
Crossmatching
Major Crossmatch
Test if patients antibodies from antigens of doors red cells
PSDR
Minor Crossmatch
dtects if donor serum has antibody for patients red cells
DSPR
Replaced Minor crossmatch
Antibody screening
Can transfuse even in ABO-incompatible patients
Plateltets
Only needs Crossmatching
RBCs
Phases of Antibody detection
- IS (RT)
- Thermophase (37C)
- AHG Phase
Phases of Antibody detection
- IS - IgM, ABO antibodies, Clerical errors
- Thermophase (37C) - Agglutinating IgG
- AHG Phase - non-agglutinating antiobodies, alloantibodies
Interpretation of Compatibility Tests
Antibody screen: (+)
Compatibility: (-)
Possible Compatible
phenotype donor to confirm compatibility
Interpretation of Compatibility Tests
Antibody screen: (+)
Compatibility: (-)
Possible Compatible
phenotype donor to confirm compatibility