Platelets

Asset 12a-Apheresis Platelets.jpgPlatelets are prepared from both apheresis and whole blood donations.

For apheresis platelets, an apheresis machine separates anticoagulated blood into components and retains a bag of platelets and a portion of plasma. The remaining elements (red and white blood cells) and the majority of the plasma are either returned to the donor or collected for preparation of other component types. The remaining platelets are resuspended in nutritive platelet additive solution (PAS). 

One, two or three adult doses of platelets may be prepared from a single apheresis platelet donation. If required, one adult apheresis platelet dose can be subdivided into three packs of equal volume to produce paediatric apheresis platelets.  This reduces donor exposure for paediatric recipients and minimises product wastage.

Whole blood derived platelets are produced by harvesting the platelets from a pool of buffy coats from four ABO identical whole blood donations.  The platelets are resuspended in additive solution to produce the pooled platelet component.

Both apheresis and pooled platelets are leucodepleted during or soon after collection and are also irradiated before release from the Blood Service, unless other specific arrangements have been made with the receiving laboratory/institution.

Platelets can be stored for 5 days after collection at 20 - 24º C with gentle agitation. Platelets can be irradiated at any stage during their 5 day storage and thereafter can be stored up to their normal shelf life of 5 days after collection.
 

Typical unit content and specifications

Information is based on the typical unit content (mean ± 1 SD) from Blood Service data (1 January to 31 December 2017 inclusive) and acceptable specification limits (in parentheses)*.

*Initial data for typical contents based on validation studies for the new component.

Volume (mL)
198 ± 11 (100–400)
Platelet count (10/unit)
274 ± 31 (> 200 to < 450)
pH 
7.2 ± 0.1 (6.4–7.6)
Leucocyte count (106 /unit)
0.1 ± 0.1 (< 1.0)
Residual plasma content (%) 
Approximately 40%

*Initial data for typical contents based on validation studies for the new component.

Volume (mL)
54 ± 3 (40-60)
Platelet count (10/unit)
68 ± 6 (> 60)
pH 
7.0 ± 0.1 (6.4-7.6)
Leucocyte count (106/unit) 
0.1 ± 0.1 (< 1.0)
Residual plasma content (%) 
Approximately 40%
Volume (mL)
336 ± 15 (> 160)
Platelet count (10/unit)
263 ± 36 (> 240)
pH 
7.0 ± 0.1 (6.4–7.4)  
Leucocyte count (10/unit)
0.2 ± 0.2 (< 0.8)
Residual plasma content (%) 
Approximately 30%

 

Availability

Platelets are available in all ABO groups and RhD positive and negative groups. Group AB are manufactured on request.
 

Modifications

Apheresis platelets can be modified as phenotyped, CMV-seronegative and HLA-compatible, crossmatch-compatible and/or low anti-A/B.

Pooled platelets can only be CMV-seronegative and/or irradiated.

 

Apheresis platelets suspended in plasma

The Blood Service stopped producing its existing apheresis platelets suspended in plasma on 28 March 2019. For a short period there will be a dual inventory alongside the new product, apheresis platelets suspended in platelet additive solution.

A comparison between the old and new products is available.

 

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