Platelets
An apheresis machine separates anticoagulated blood into components with retention of the platelets and a portion of plasma to create a standard adult dose of Platelet Apheresis. The remaining elements may be returned to the donor.
The platelet apheresis unit is then divided into four packs of equal volume to produce a Paediatric Platelet Apheresis component. This is to reduce donor exposure for small paediatric transfusions and to minimise product wastage.
An adult dose of platelets derived from whole blood is obtained from a pool of buffy coats from ABO identical donors and resuspended in a nutrient additive solution to produce a Platelet Pooled Leucocyte Depleted component.
Leucocyte depletion is performed during or soon after collection to remove most leucocytes.
Both apheresis and pooled platelets are irradiated before release from the Blood Service, unless other specific arrangements have been made with the receiving laboratory/institution.
| Specifications of Platelets | |||
| Platelet Apheresis Leucocyte Depleted | Platelet Paediatric Apheresis Leucocyte Depleted | Platelet Pooled Leucocyte Depleted | |
| Volume | 100–400 mL | 40–60 mL | > 160 mL |
| Platelet count | > 200 x 109 per unit | > 60 x 109 per pack | > 240 x 109 per pool |
| pH (at expiry) | 6.4–7.4 | 6.4–7.4 | 6.4–7.4 |
| Leucocyte count | < 1.0 x 106 per unit | In the starting component, ie, prior to splitting < 1.0 x 106 | < 0.8 x 106 per pool |
Availability
Adult doses of platelets are available in groups O, A and B; and, Rh(D) positive and negative groups; however, group AB must be requested in advance.
You must contact the Blood Service to check the availability of paediatric apheresis components.
Modifications
Platelets collected via apheresis can be modified as phenotyped, CMV-seronegative, irradiated, HLA-compatible, crossmatch-compatible and/or low anti-A/B.
Pooled platelets can only be CMV-seronegative and/or irradiated.
