Phenotyping can be performed for red cells and platelet components.
Phenotyped components are used to:
- prevent alloimmunisation, and
- provide compatible red cells for transfusion in patients with clinically significant antibodies.
Patients who have a clinically significant antibody or have a history of a clinically significant antibody, should be provided with red cells negative for the relevant antigen.
The table provides the frequency of negative phenotypes for antibodies generally considered to be clinically significant.
Clinically significant antigen frequency
| Antigen | Frequency of negative phenotype |
|---|---|
| D | 17.9% |
| C | 47.3% |
| c | 17.5% |
| E | 71.6% |
| e | 2.4% |
| K | 90.9% |
| k | 0.4% (rare) |
| Jka | 23.6% |
| Jkb | 26.3% |
| S | 48.0% |
| s | 9.4% |
| U | 0.01% (rare) |
| Fya | 32.7% |
| Fyb | 19.7% |
A full list of major blood group phenotypes can be found here.
For patients who have non-clinically significant antibodies, the red cells don’t need to be antigen negative for the corresponding antibody.
The following table provides the frequency of negative phenotypes for those antibodies generally considered not to be clinically significant.
Clinically non-significant antigen frequency
| Antigen | Frequency of negative phenotype |
|---|---|
| A1 | 20% (of group A) |
| HI (in A1 and A1B) | N/A |
| CW | 98% |
| Kpa | 97.8% |
| M | 21.5% |
| N | 29.5% |
| P1 | 25.2% |
| Lea | 77.6% |
| Leb | 27.7% |
| Lea+b | 5.3% |
| Lua | 92.3% |
| Wra | 99.9% |
For patients with rare red cell phenotypes or have multiple antibodies, Lifeblood will need to locate suitable red cell units. If there isn’t a compatible unit readily available, Lifeblood may need to:
- contact particular phenotyped donors to arrange donation
- access phenotyped red cells from frozen inventory, or
- request assistance from international blood services.
