Update notice: text HIGHLIGHTED has changed following the issue of Change Notification 04 - 2009
8.8 Red Cells, Thawed and Washed, Leucocyte Depleted
A red cell component, that contains less than 5 x 106 leucocytes, frozen in the presence of a cryoprotectant (preferably within five days of collection), and washed before use. Red Cells, Thawed and Washed, Leucocyte Depleted may then be suspended in an approved additive solution.
Technical information
The concentration and nature of the cryoprotectant must provide appropriate protection of the red cells at the intended storage temperature. The entire process of freezing, thawing and washing must be validated and documented.
The use of validated washing procedures that incorporate chilled saline, at least for the final wash and chilled approved additive solution for suspension, is recommended. This will minimize the risk of bacterial contamination and helps to produce a component that meets the transit temperature requirements.
The target minimum haemoglobin content is 36g.
If the washing process results in the transfer of the final component into a pack that was not part of the original pack assembly, a secure system must be in place to ensure the correct donation identification number is put on the pack in which the component is frozen and the pack in which the final component is presented.
Red Cells, Thawed and Washed, Leucocyte Depleted should be transfused through a 170–200 µm filter.
Labelling (for general guidelines see Section 7.5)
The following shall be included on the label:
(* = in eye-readable and UKBTS approved barcode format.)
red cells, thawed and washed, Leucocyte Depleted* and volume
the blood component producer's name*
the donation number*
the ABO group*
the RhD group stated as positive or negative*
the name, composition and volume of the suspending solution*
the date and time of preparation
the expiry date and time*
the temperature of storage
the blood pack lot number.*
In addition, the following statements should be made:
INSTRUCTION
Always check patient/component compatibility/identity
Inspect pack and contents for signs of deterioration or damage
Risk of adverse reaction/infection
Storage (for general guidelines see Section 7.6)
Maintenance of a constant storage temperature is important, particularly if a low glycerol cryoprotectant system is used. Storage should be controlled to ensure
–60°C to –80°C if stored in an electrical freezer, when a high glycerol method is used
–140°C to –150°C if stored in vapour phase liquid nitrogen, when a low glycerol method is used
The storage may extend to at least 10 years, if the correct storage temperature is guaranteed.
The component should be used as soon as possible. Where the component has been produced from a closed system and storage is required the component should be stored at a core temperature of 4°C±2°C and used within 24 hours of production if suspended in saline or a defined validated period if suspended in an approved additive solution.
Testing
In addition to the mandatory and other tests required for blood donations described in Chapter 10, and leucocyte counting (see Sections 7.2 and 8.1), a minimum of 75% of those components tested for the parameters shown in Table 8.5 shall meet the specified values. Provided the component is prepared from a process that is validated for leucocyte removal, testing of washed red cells for residual leucocytes is not required.
Table 8.5 Red cells, thawed and washed, leucocyte depleted – additional tests
| Parameter | Frequency of test | Specification |
|---|
| Volume |
All |
Within locally defined nominal volume range |
| Supernatant Hb |
10 per month or, if made less frequently, every component |
≤2 g/unit
|
| Red cell Hb |
≥36 g/component |
| Leucocyte count* |
As per Sections 7.2 and 8.1 |
<5 x 106/unit** |
*Methods validated for counting low numbers of leucocytes must be used.
**Prefreeze.
Transportation (for general guidelines see Section 7.10)
The transport requirements for red cells in the frozen state will be influenced by the nature and concentration of cryoprotectant used: e.g. a component containing <20% glycerol requires a refrigerant colder than dry ice, such as the vapour phase of liquid nitrogen.
For red cell components, transit containers, packing materials and procedures should have been validated to ensure the component surface temperature can be maintained between 2°C and 10°C during transportation. Additionally:
the validation exercise should be repeated periodically
if melting ice is used, it should not come into direct contact with the components
dead air space in packaging containers should be minimized
as far as is practicable, transit containers should be equilibrated to their storage temperature prior to filling with components
transport time normally should not exceed 12 hours
in some instances it is necessary to issue red cell components that have not been cooled to their storage temperature prior to placing in the transit container. The transport temperature specified above is not applicable for such consignments.