Table 2.
mAb Isotype Binding Affinity to Polymorphic FcγR Subtypes
| Characteristic | CD64, FcγRI | CD32 |
CD16 |
|||
|---|---|---|---|---|---|---|
| FcγRIIa | FcγRIIb | FcγRIIc | FcγRIIIa | FcγRIV | ||
| Affinity | High | Medium | Low | Low | Medium | Medium |
| Specificity | High | Low | Medium | Low | Medium | High |
| Isotype that binds preferably | IgG1, IgG3 | IgG1, IgG3 | IgG1, IgG2 | IgG2a, IgG2b | IgG1 | IgG2a, IgG2b |
| Comments | 131-R/R genotype has lower affinity for IgG1 | Inhibitory receptor | 176-F/F most common genotype, associated with lower affinity for IgG1 | |||
Abbreviations: mAb, monoclonal antibody; FcγR, Fcγ receptor; Ig, immunoglobulin.