HLA Antibody Detection Flashcards
Majority of HLA Antibodies belongs to the
IgG
Uknown serum is added to a
Panel of antigen with known HLA phenotype
A panel of at least ____ is required for Initial screening
30 cells
A panel of at least ____ is required for Antibody identification
60 cells
Microlyphocytotoxicity Test:
Alloantisera reagent uses
CDC
Standard Complement-dependent microlymphocytotoxicity Test
Microlyphocytotoxicity Test:
Screening for Recipient serum
Amos-modified Techniques
Extended Incubation
AHG Test
Process of washing cell after initial serum incubation for removing anti-complementary activity of serum
Amos-modified
AHG added in the CDC modification will bind to the _____ chain of IgG, promoting ______
Light Chain
Complement Activation
AHG added in the COOMBS TEST will bind to the _____ chain of IgG, promoting ______
Heavy Chain
Agglutination
Can distinguish IgM and IgG isotype
Distinguish non-HLA and HLA antibodies
More sensitive
Cannot be used solely for clinical-decision making
Newer Detection method for HLA Antibody Testing
Why does Final crossmatching for specific donor is still needed even if newer method for HLA antibody is used
Not all HLA antigen are present in pool/panel
Uses Purified HLA antigens instead of Lymphocytes with 2 types of Assay:
- Screening Assay
- Specificity Determination Assay
ELISA
Enzyme Linked Immunoabsorbent Crossmatch Assay
ELISA
uses purified HLA antigen to detect anti-HLA antibodies
Screening Assay
ELISA
uses purified HLA antigen to detect antibody specificity
Specificity Determination Assay
Most sensitive technique in HLA antibody screening
Flow Cytometric Antibody Screen
Flow cytometric Antibody Screen uses
T and B Lymphocytes
Purified HLA antigen
Flow cytometric Antibody Screen is most effective since it does not need to activate Complement, it directly detects antibody binding
T/F
True
HLA antibody screen by which the patient sera is tested against recombinant HLA antigen panel each is bounded with MICROBEADS and labeled with FLUOROPHORE
Multiplex Immunoassay (LUMINEX)
Positive Reaction for Multiplex Immunoassay
Mean Fluorescence Intensity
Percentage of cells in the panel that the serum was capable of binding
Panel Reactive Antibody
PERCENT PRA is represented by
Percentage of Pooled beads (react + with serum)
Proportion of population to which patient will react via PREEXITING ANTIBODIES
Panel Reactive Antibody
People with High PRA do not need to wait longer for Organ transplant
T/F
False
Individual w/ high PRA tends to wait longer for an Organ since they have wide percentage antibodies that can react against large number of population
