Table 1. Level of HLA Typing Currently Used for Different Hematopoietic Stem Cell Sourcesa,b,c

Class I Antigens Class II Antigens
Stem Cell Source HLA A HLA BHLA CHLA DRB1 HLA DQB1; HLA DPB1; HLA DR3,4,5
Matched siblingd BM/PBSCsAntigen or allele Antigen or alleleOptionalAllele
Mismatched sibling/other related donore BM/PBSCsAllele AlleleAllele Allele Recommended, if mismatches are present
Unrelated donor BM/PBSCsAllele Allele AlleleAllele Recommended, if mismatches are present
Unrelated donor cord blood Antigen (allele recommended ) Antigen (allele recommended ) Allele recommended Allele

BM = bone marrow; PBSC = peripheral blood stem cells.

aHLA antigen: A serologically defined, low-resolution method of defining an HLA protein. Differs from allele-level typing half of the time. Designated by the first two numbers (i.e., HLA B 35:01—antigen is HLA B 35).

bHLA allele: A higher resolution method of defining unique HLA proteins by typing their gene through sequencing or other DNA-based methods that detect unique differences. Designated by at least four numbers (i.e., HLA B 35:01).

cConsensus recommendations for HLA typing, including extended class II typing of mismatched donors, have been published from the National Cancer Institute/National Heart, Lung, and Blood Institute–sponsored Blood and Marrow Transplant Clinical Trials Network.[10]

dSiblings need confirmation that they have fully matched haplotypes with no crossovers in the A to DRB1 region. If parental typing is performed and haplotypes are established, antigen-level typing of class I is adequate. With no parental haplotypes, allele-level typing of eight alleles is recommended.

eParent, cousin, etc., with a phenotypic match or near-complete HLA match.

From: Childhood Hematopoietic Cell Transplantation (PDQ®)

Cover of PDQ Cancer Information Summaries
PDQ Cancer Information Summaries [Internet].
Bethesda (MD): National Cancer Institute (US); 2002-.

NCBI Bookshelf. A service of the National Library of Medicine, National Institutes of Health.