Table 1.
Comparison of the dominant characteristics of classes 1 and 2 donor-specific antibodies (6–10,25–30)
| Class 1 Donor-Specific Antibodies | Class 2 Donor-Specific Antibodies | |
|---|---|---|
| HLA | ||
| Antigens | A, B, and C | DR, DQ, and DP |
| Epitopes location | α-chain | α- and β-chains |
| Expression | All nucleated cells | Antigen-presenting cells |
| Preformed donor-specific antibodies | ||
| Important | Very | Less |
| Positive crossmatch | T cells | B cells |
| Transplant decision | No transplant | Permissible |
| De novo donor-specific antibodies | ||
| Detection | Sooner | Later |
| IgG subclasses | IgG1, IgG3 | IgG2, IgG4 |
| Complement binding | Strong | Weak/no |
| Frequency | Fewer | Common, especially DQ |
| Antibody-mediated rejection | ||
| Phenotypes | Acute | Chronic, subclinical |
| Presentation | Early | Later |
| Graft dysfunction | Rapidly | Slowly |
| C4d deposit | Positive | Negative |
| Treatment | More responsive | Less responsive |
| Graft loss | Early | Later |