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Comparison between in vitro properties of washed platelet concentrates suspended in M-sol and those in BRS-A, both of which were prepared with an automated cell processor��Akira Iwamaa, Junichi Hirayamaa,∗, Masayuki Nogawaa, Masayuki Shibaa,Masahiro Satakea, Shigeru Takamotob, Kenji Tadokoroa�a.Central Blood Institute, Japanese Red Cross Society, Tokyo, Japan�b.Japanese Red Cross Hokkaido Block Blood Center, Sapporo, Japan

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Introduction�

Washed platelet concentrates(WPC) is usefull for preventing transfusion –related adverse reaction caused by plasma component.This method is prepared by removing almost all plasma form centrifuged platelet concentrated and adding addiction solution to the pellet.
In general WPC is prepared manually,recently new software for automated cell processor were develop in japan to minimize variation in the WPC quality and enhance WPC production.In this test,they were using 2 addictive solution which is M-sol and BRS-A.
This two solution were not commercially available,but were made by mixing few commercial component.This are the study to compare in vitro properties between WPC-M(M-sol) and WPC-B(BRS-A) during 7-day storage.

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Table 1
Composition of M-sol and BRS-A(milimol/L)

M-sol BRS-A

sodium chloride 77 95.2

pottasium chloride 3.0 3.8

magnesium chloride 1.6 0.9

sodium bicarbonate 44 26.6

glucose 15 5.8

sodium acetate 21 -

trisodium citrate 9.4 4.2

citric acid 4.8 1.8

calcium chloride 1.0 1.4

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Material and methods

WPC preparation and storage:

Two ABO identical apheresis-derived platelet concentrate from healthy donor were mixed and divided into 2 equal aliquots(for WPC-M and WPC-B).

BRS-A were prepared by mixing BICANATE(ringer solution) and ACD-A(anti-coagulant dextrose solution-A).

M-sol were prepared by mixing chemical as shown in table 1.

The operating o the ACP was performed according to the manufacturer`s protocol

The final composition of M-sol and BRS-A are shown in table 1.

Prepared WPC was stored at 20-24 degree celcius on a flatbed shaker for 7 days.

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Measurement of basic variables

PLT recovery and plasma carryover were calculated as:
PLT recovery(%) = 100x (total PLT count in WPC on day 0)

total PLT count in PC

Plasma removal(%)=
100x (1 - total protein weight in WPC supernatant on day 0)

total protein weight in PC supernatant

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Test that were conducted for WPC:

1.supernatant protein concentration=BCA method with protein assay kit
2.platelet aggregation=Platelet aggregometer
3.hypotonic shock response=spectrofotometer
4.glucose and lactate=commercial kit for glucose and lactate

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Result:

The characteristic of PC and both prepared WPC are describe in table 2 and PH value for both WPC were maintained above 6.8 during the 7 day storage.

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Discussion:
During 7-days storage,in-vitro properties of WPC were studied,the plasma removal rate on WPC preparation with ACP was 99%(Table 2),while manual method was 95-97%.
These result clarified that in-vitro properties of WPC-B are not markedly different from those of WPC-M until day-3.This 3-days period is enough as expiration of WPC prepared from PC.

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WASHED PLATELET IN PDN

Definition:

Washed platelet is platelet prepared by sequential washing in an isotonic solution to remove plasma protein before resuspention into saline.Platelet shall be used immediately or within 6 hours after preparation.

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Procedure:
Recieve request for washed platelet from Inventory division/MO/specialist on call in Pusat Darah Negara.
Select and identify platelet apheresis or random platelet(pooled) unit to be washed.
Recieve bag from inventory and acknowledge report in BBIS.
Change product component in system,reprint barcode.
*Sterile dock platelet bag to an empty transfer bag
*Pack and balance the platelet bag into centrifuge bucket.

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*Spin the platelet bag at 22 degree celcius using hard spin program(rpm=3800,10 minute).
*Remove the centrifuged platelet and place it on a manual plasma expressor
*Express all the plasma into the transfer bag,leaving a pellet in the platelet bag.Seal the tubing,detach the plasma bag and store it as recovered plasma if necessary,otherwise discard it.

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Washing procedure:
First washing cycle:Aseptically spike and transfer normal saline(0.9%)gradually into the platelet bag and gently resuspend the platelet button until all the platelet are dispersed.Seal the tubing after 400ml normal saline(0.9%) has been transfer into the platelet bag
Sterile dock the platelet bag into new transfer bag.

repeat step marked *.

Second washing cycle:Aseptically spike and transfer normal saline(0.9%)gradually into the platelet bag and gently resuspend the platelet button until all the platelet are dispersed.Seal the tubing after 400ml normal saline(0.9%) has been transfer into the platelet bag.Repeat step marked *.

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Final step:Aseptically spike and add 300ml or equivalent to the original prewashed platelet volume of normal saline(0.9%) gradually to resuspend the washed platelet.
Quarantine product into BBIS system.Unquarantine product to generate screened label and paste it onto final product bag.
Issue to inventory.
Product will expired in 6 hours,due to the open system procedure.