Table 2. Definitions of the Numbers Describing Human Leukocyte Antigen (HLA) Antigens and Alleles Matching
| If These HLA Antigens and Alleles Match | Then the Donor is Considered to be This Type of Match |
| A, B, and DRB1 | 6/6 |
| A, B, C, and DRB1 | 8/8 |
| A, B, C, DRB1, and DQB1 | 10/10 |
| A, B, C, DRB1, DQB1, and DPB1 | 12/12 |