Function and activation state of platelets in vitro depend on apheresis modality.
OBJECTIVE
In multicomponent collection, various blood components are prepared during one apheresis process. The aim of this prospective crossover study was to compare the function, metabolic parameters and activation state of fresh and stored platelets (PLTs) collected by two different cell separators.


METHODS
Twenty-four donors underwent apheresis on each of two cell separators (Fenwal Amicus(®) and CaridianBCT Trima Accel(®)) with an interval of at least 2 months between donations. Per donation, one double dose of PLT concentrate (PC) and one unit of packed red-blood-cells were collected. In total, 48 single unit PCs were tested for pH, glucose, bicarbonate, lactate, potassium and LDH concentration during 7 days of storage. PLT function was analysed by aggregometry, rotation thrombelastometry and hypotonic shock response. The PLT surface expression of P-selectin (CD62P) and LAMP-3 (CD63) was estimated by flow cytometry.


RESULTS
During storage, metabolic parameters were well maintained in both groups, but levels of glucose and pH were significantly lower, while lactate and LDH were significantly higher in Amicus(®)-PCs. Amicus(®)-derived PLTs were significantly more activated as evidenced by higher CD62P and CD63 expression. In parallel, the in vitro function of Amicus(®)-PLTs was significantly reduced compared to Trima(®)-PLTs.


CONCLUSIONS
In multicomponent apheresis, standardized PLT collection is effective and well tolerated. The higher activation of Amicus(®)-derived PLTs may be because of the divergent centrifugation modalities during collection. Possible consequences for the clinical outcome of thrombocytopenic patients will be evaluated in further trials.
Macher
S
S
Clinic for Blood Group Serology and Transfusion Medicine, Medical University of Graz, Graz, Austria.
Sipurzynski-Budrass
S
S
Rosskopf
K
K
Rohde
E
E
Griesbacher
A
A
Groselj-Strele
A
A
Lanzer
G
G
Schallmoser
K
K
D000328:Adult; D015703:Antigens, CD / Q000096:biosynthesis; D001781:Blood Component Removal; D001782:Blood Donors; D001792:Blood Platelets / Q000166:cytology* / Q000378:metabolism*; D018592:Cross-Over Studies; D005260:Female; D005786:Gene Expression Regulation; D006801:Humans; D008297:Male; D008875:Middle Aged; D009997:Osmotic Pressure; D019007:P-Selectin / Q000096:biosynthesis; D015539:Platelet Activation; D010980:Platelet Membrane Glycoproteins / Q000096:biosynthesis; D011446:Prospective Studies; D012034:Refrigeration; D060149:Tetraspanin 30; D013916:Thrombelastography; D013997:Time Factors
D015703:Antigens, CD; C554586:CD63 protein, human; D019007:P-Selectin; D010980:Platelet Membrane Glycoproteins; D060149:Tetraspanin 30