Adverse Rxn & Molecular Testing Flashcards
1
Q
HLA properties
A
- Present peptide to TCR (self-recognition & immunological defense)
- Polymorphic
- Co-dominant
- Mendelian rules
- Ethnical difference
- Patient create Abs against HLA protein
2
Q
HLA Molecular Typing
A
- Genotyping
- RT- PCR
3
Q
HLA Antibody Testing
A
- Luminex: Result (CPRA) sent to UNET - Higher number (percentage) means less compatible donor.
- Flow Cytometric Crossmatch
4
Q
Application of HLA testing
A
- Organ transplantation
- PLT transfusion
- TRALI investigation
- Disease association/treament
5
Q
Solid organ Tx vs HSC Tx
A
- Solid organ: avoid HLA Abs pre-formed from patient
- HSC: HLA matching to avoid GvHD
6
Q
HLA & PLT Refractoriness
A
- When suspicious, pt is tested for HLA class I Abs
- Pt should receive HLA I -negative for that specific Abs
7
Q
Strategies for “compatible” PLT
A
- HLA matched PLT
- Avoid HLA specificities based on Abs
- PLT XM
- Acceptable HLA mismatches
8
Q
HLA & TRALI
A
- Transfusion Induced Lung Injury
- Donor’s blood has HNA, HLA I, HLA II
- Activate patient’s HLA activate neutrophils and endothelial cells
9
Q
HLA Prevention
A
- Screen for HLA Abs only for female donor donating PLT and AB Plasma
- Donors positive for HLA Abs will be deferred forever
10
Q
RBC Genotyping vs Phenotyping
A
- Genotype: RBC antigen predicted by DNA sequence at a particular location on chromosome
- Phenotype: RBC antigen expressed as determined with serologic method
11
Q
Problems with serological typing
A
- Multiple RBC population
- Interfering Abs
- Discrepant results or undetectable underlying genetic differences in blood group Ag
- No antisera available
- No sample avaialble
12
Q
Indications for RBC genotyping
A
- Post-transfusion
- Discrepant serologic results
- Unable to detect
- No antisera
- Interfering Abs
- No sample (fetus)
- Zygosity matters
- Desire to RBC type large number of people
13
Q
Acute Immunologic TR
A
- During or w/in 24hrs of transfusion
- DAT positive
- Increase bilirubin; LDH;
- Decrease: hemoglobin, haptoglobin;
14
Q
Acute Non-immunologic TR
A
- During or w/in 24hrs of transfusion
- DAT negative - Independent with Abs
- Asymptomatic; hemoglobinuria
- Caused by chemical or physical damage (improper shipping & storage)
15
Q
Delay Immunologic TR
A
- After 24hrs
- AbSC switch from neg to pos
- If DAT positive, perform eluate –> Eluate positive —> Antigen typing units transfused.
- Other markers of hemolysis: LDH, Total bilirubin, direct bilirubin, haptoglobin
