Function of platelets in apheresis platelet concentrates and in patient blood after transfusion as assessed by Impact-R.
BACKGROUND
Platelet (PLT) transfusion is a mainstream therapy for preventing or treating bleeding episodes in patients with thrombocytopenia. The efficacy is usually estimated from the corrected count increment of PLTs after transfusion, which does not assess PLT function. We therefore evaluated PLT function in blood samples of patients with thrombocytopenia before and after transfusion.


METHODS
PLT function was assessed in 24 chemotherapy-treated patients and in the PLT concentrates (PCs) by the Impact-R (DiaMed). This device evaluates PLT adhesion and aggregation recorded as surface coverage (%) and size of aggregates (AS microm(2)). P-selectin expression was determined by flow cytometry.


RESULTS
The PCs were stored for a median of 70 hours before transfusion. An analysis stratified by the median storage of PCs (<70 hr or >70 hr) showed no differences in the SC, the AS, and P-selectin expression between these concentrates' groups. Transfusion resulted in an increase of adhering PLTs in the patients after transfusion. There were no differences in the AS and in P-selectin expression before and after transfusion, but the AS increased after transfusion upon ex vivo exposure to adenosine 5'-diphosphate. P-selectin expression was significantly lower in the patient group receiving PCs stored for more than 70 hours.


CONCLUSIONS
The current trial shows the feasibility of using the Impact-R to assess the function of transfused PLTs in the patient's blood stream.
Horvath
Michaela
M
Clinical Department of Blood Group Serology and Transfusion Medicine, Medical University Vienna, Vienna, Austria.
Eichelberger
Beate
B
Koren
Daniela
D
Böhm
Alexandra
A
Ay
Cihan
C
Jilma
Bernd
B
Panzer
Simon
S
Jilma-Stohlawetz
Petra
P
D000328:Adult; D000368:Aged; D001792:Blood Platelets / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D019007:P-Selectin / Q000097:blood; D010979:Platelet Function Tests / Q000295:instrumentation*; D017713:Platelet Transfusion; D010983:Plateletpheresis
D019007:P-Selectin