- EDTA (plasma): more suitable for automated systems, but may miss weak, complement-binding antibodies
- Clotted samples (serum): haemolysis can indicate a positive reaction in the reverse group or IAT.
- Serum samples are recommended wherever possible for investigation of transfusion reactions as they are better at identifying weak antibodies such as Jka, which might be detectable only by the complement bound to red cells.
- Laboratories should have a sample acceptable policy covering the labeling and condition of samples.
- Samples must not be taken more than 3 days from the date of anticipated transfusion, to ensure that it is representative of the recipient’s current immune status. This is especially true when the recipient has been transfused or pregnant within the last 3 months, or that information is unknown.
- For patients not transfused or pregnant within the last three months, there may be deviation from the 3-day rule (see table below).
Patient | Whole blood at room temp | Whole blood at 2 – 8°C | Plasma at -30°C |
Not pregnant and not transfused in the last 3 months | 48 hours | 7 days | N/A |
Pregnant or transfused in last 3 months | 48 hours | 3 days | 3 months |
- Samples should be retained for at least three days post-transfusion, so as to allow for re-testing should haemolytic transfusion reactions occur.
- Plasma samples should be kept for at least 7-14 days post-transfusion to allow for investigation of any possible delayed haemolytic transfusion reaction.
- These samples should be stored in a way that minimises the risk of an out-of-date sample being selected for pre-transfusion testing.
Hi
Many thanks for your great effort. Just wanted to check that there is no typo error in the table. The table above mentions that the sample is valid for 7 days in case of transfusion or pregnant in the last 3 months , OR 3 days validity if there is no transfusion or pregnancy in the last 3 months. Is it not supposed to be the opposite?
Regards
Dr R Al-Khatib
Yes, you are correct. Thank you for your feedback!