Thrombocytes, leukocytes removed, pooled

Characteristics
The product is prepared by adding three or five buffy coats from identical ABO and Rh-D compatible blood groups to plasma or with a mixture of plasma and thrombocyte storage fluid. The cells are then centrifuged so that there is sedimentation and that the uppermost suspension with thrombocytes can be divided off and filtered.

The desired dose can be achieved by adding more units of thrombocytes or buffy coats together. The desired number of thrombocytes should be obtained from as few donor units as possible. The dose for an adult consists of 5 donor units or is prepared from 5 buffy coats.

The volume of the product prepared from 5 donor units (5 buffy coats) for adults is 150 – 400 mL, the number of thrombocytes is a minimum of 250 x 109, and the residual number of leukocytes is less than 1 x 106 . Further characterisation as described above.

If the product is prepared for larger (30 Kg) children from 3 donor units (3 buffy coats) or a mixture of plasma and storage fluid, then the volume is 150 – 250 mL plasma, with a minimum therein of 150 x 109 thrombocytes and less than 1 x 106 leukocytes.

The volume of storage medium is adjusted in order to maintain a pH between 6.8 and 7.4 and to guarantee the presence of the ‘swirling effect’ (as an indicator of the morphology). To the degree that there is more plasma present in the storage medium, it will contain more plasma proteins (although unstable coagulation factors are practically absent), the potassium is physiologic, the sodium is lightly elevated, and the glucose is (dependant upon the storage medium) lightly elevated to physiologic. There are practically no free calcium ions present and the citrate amount alternates between 15 and 25 mmol/L. The pH and glucose amount go down, and the lactate content increases, during the storage. The possibly present plasma contains no irregular antibodies against erythrocytes.

Indication
Standard thrombocyte product.

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