Wednesday, February 6, 2019
HLA antibody testing part 9
Solid-phase bead assays may be supplied as pooled antigen panels, single-patient phenotypes, or single antigen beads. Pooled panel beads with many different class I or II HLA antigens on a bead yield a positive/negative result and are used for screening. Phenotype (also called ID) beads are each coated with class I or II HLA antigens of an individual patient derived cell line and estimate panel-reactive antibody by the percentage of positive beads. Single antigen beads are each coated with a single HLA antigen and yields a list of discrete antibody specifities. Specifities are then compared with HLA frequencies in the donor population to determine the calculated panel-reactive antibody, which is presently the best estimate of likeli-hood of a positive crossmatch assays/donor-specific HLA antigen to a randomly selected donor. Single antigen beads results further enable virtual crossmatching to identify donor-specific antigen pretransplant, in turn fascilitating allocation and risk assessment. Virtual crossmatching has also been used without cell-based crossmatch in some transplant circumstances where legislation permits, or under study conditions, with acceptable (equivalent rejection rates and graft survival at a population level) results. Additional enhancements of the single antigen beads assay, such as detecting antibodies capable of binding complement component C1q, have been developed to detect potentially more injurious antibodies.
Subscribe to:
Post Comments (Atom)
No comments:
Post a Comment