The appearance of an antibody post-transfusion is a sign of a delayed transfusion reaction. Only when there is evidence of increased red cell destruction is the reaction termed a T hemolytic reaction. The appearance of an antibody without cell destruction is a delayed serologic reaction.
Table 3: Delayed Transfusion Reactions - Testing| Delayed Reaction Type | Testing |
| Alloimmunization | - DAT, eluate if positive
- Antibody screen
|
| Alloimmunization to HLA antigens | - Platelet antibody screen
- Lymphocytotoxicity testing
|
| Delayed hemolytic | - DAT, eluate if positive
- Antibody screen
- Other tests for hemolysis
|
| Transfusion-associated graft-vs-host disease | - HLA typing
- Cytogenetic analysis
|
| Infectious disease transmission | - Specific testing for antigens or antibodies associated with the disease
|
| Iron overload | - Serum ferritin
- Liver enzymes
- Endocrine function tests
|
| Post-transfusion purpura | - Platelet antibody screen/identification
|
