Characteristic | Warm-reactive AIHA | Paroxysmal cold hemoglobinuria | Cold agglutinin disease |
Autoantibody isotype | IgG | IgG | IgM |
Thermal reactivity | Warm | Cold | Cold |
Ability to fix complement | Variable | Yes | Yes |
DAT (Coombs test) result | 4°C: Not typically performed 37°C: Positive for IgG, ± C3 | 4°C: Positive for IgG and C3 37°C: Negative for IgG; positive for C3 | 4°C: Negative for IgG; positive for C3 37°C: Negative for IgG; positive for C3 |
Antigenic reactivity | Rh, others | P | I or i |
Site of hemolysis | Spleen | Intravascular | Liver, intravascular |
First-line therapy | Glucocorticoids | Avoidance of cold | Avoidance of cold |
Secondary therapy | Splenectomy, Rituximab* | Glucocorticoids | Rituximab* |