ELISA – This technique is highly sensitive and
specific for IgG HLA antibodies.
Testing is available for both HLA Class I antibodies and HLA Class
II antibodies. This technique
is not complement dependent and is capable of detecting antibodies that are
not cytotoxic. ELISA antibody
testing is qualitative.
Cytotoxic (Extended Incubation) – This method is
moderately sensitive of HLA Class I IgM and IgG antibodies. It is primarily useful for detecting IgM reactivity since this is not detectable with non-cytotoxic techniques
and is not reliably detected with antihuman globulin (AHG). IgM antibodies are distinguished
from IgG antibodies by treatmentment of the serum with dithiothreitol (DTT).
Cytotoxic (AHG) – This method is very sensitive
for HLA Class I IgG antibodies.
It may detect IgM as well, though it is not as reliable.
Flow Cytometry – This method is extremely
sensitive for IgG antibodies and is used primarily to characterize
reactivity detected in crossmatching which is not explainable by cytotoxic
antibody testing. Flow
Cytometric antibody testing utilizes purifed HLA antigens bound to beads
for either screening or high definition antibody assays. Testing is
available for both HLA Class I antibodies and HLA Class II antibodies.
It is recommended that prospective solid organ
transplant recipients be tested:
as a part of their initial histocompatibility workup, monthly until
transplanted, and weekly for four weeks after any significant immunizing
event. The Immunogentics and
Transplantation Laboratory utilizes a multi-faceted approach of HLA
antibody testing. Tthe testing
can include one or all of the following tests: ELISA, Cytotoxic (Extended Incubation
and\or AHG), and Flow. Each
sample subsequent to the initial workup is reflexed based on the results
from the previous sample tested.