Authors: Mary A. Williamson Mt(ascp) Phd,L. Michael Snyder Md
Intermediate-resolution typing of HLA-A, HLA-B, and HLA-DRB1 loci
If matched with the recipient, high-resolution typing of HLA-A, HLA- B, HLA-C, HLA-DRB1, and HLA-DQB1 loci and intermediate-resolution typing of HLA-DQA1 and HLA-DRB345 loci.
Identity confirmation by intermediate-resolution typing of HLA-A, HLA-B, and HLA-DRB1 loci with a new sample
Unrelated donor search and typing
If a suitable matched related donor cannot be found, an unrelated donor search will be initiated. Transplant physicians, coordinators, and HLA lab staff will be involved in the donor search and selection. NMDP, BMDW, and individual donor registries will be searched using the patient’s high-resolution typing data.
High-resolution typing of HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 loci and intermediate-resolution typing of HLA-DQA1 and HLA-DRB345 loci are performed for selected unrelated donors. Additional DPB1 matching can improve transplant outcome.
A 10/10 allele-matched unrelated donor is preferred. Mismatched donors will be evaluated on a case-by-case basis. If the patient has HLA antibodies, especially the class II antibodies, a final T- and B-cell crossmatch with the unrelated donor may be necessary. The most current patient serum on file is preferred for the final crossmatch.
Cord blood search and typing
If a suitable matched related donor cannot be found, a cord blood unit search will be initiated. NMDP, BMDW, and individual cord blood registries will be searched using the patient’s high-resolution typing data.
High-resolution typing of HLA-A, HLA-B, HLA-C, HLA-DRB1, and HLA-DQB1 loci and intermediate-resolution typing of HLA-DQA1 and -DRB345 loci on the selected cord(s), attached segments preferred if available, cord bag can be used as well for retrospect typing. If resources are limited, whether financial or sample material, only high-resolution typing of HLA-A, B, and DRB1 loci will be performed.
When a suitable family donor is not available, the choice of an unrelated donor or cord blood will depend on the degree of HLA match, cell dose of the cord blood unit, the urgency of the transplant, and other variables (donor age, sex, ABO incompatibility, HLA antibody, etc.) that may affect the transplant outcome.
Patient and donor identity confirmation