الفهرس 
Introduction And Aim Of The WorkOnly 14 pages are availabe for public view
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Abstract
The requirements for platelet transfusion have been greater than before. The platelet concentrates can be stored up to 5 days and this limitation results in the outdating of units and complicates the process of platelet inventories in blood banking. Therefore, there is a considerable interest in developing methods to lengthen the shelf life of PCs.
Several cryoprotectants were found to be helpful for platelet freeze/ thawing and dimethylsulphoxide (DMSO) at higher concentrations (5–6%) is currently considered of paramount in platelets cryoprotection.
Our study aimed to evaluate the quality of cryopreserved platelet product and determine the effect of storage on platelet activation.
Twenty subjects obeyed to platelet donor criteria were included in the study conducted at Department of Clinical Pathology, Minia University Hospital in conjunction with Minia Regional Blood Transfusion Centre in the period between January 2014 and May 2014.
Separated platelets were stored at 22oC with agitation. On Day 1 of storage, filtered 6% DMSO was added and the platelet product frozen directly into a -80oC freezer for 5 months and post thawing samples were taken. So, we had three types of samples: 1) Pre freezing samples or day (0) samples. 2) Day (5) samples. 3) Post thawing samples. Platelet recovery and function assay was determined by measuring platelet count, mean platelet volume (MPV), pH, bicarbonate, PO2 and PCO2 levels, Regulated on activation normal T cell expressed and secreted (RANTES), Annexin V, and platelet response to adenosine diphosphate (ADP) and collagen by aggregation.
The Platelet function was affected during the storage for five days and freeze–thaw process. There were an overall decrease in ADP and collagen induced platelet aggregation in day 5, and post thawing as compared with day 0, with P=0.001. On comparing values of ADP and collagen induced platelet aggregation of post thawing with that of day 5, there was significant decreased levels in day 5 (P= 0.001).
RANTES was significantly increased in day 5, and post thawing as compared with day 0, with P= 0.001. But there was no significant difference when comparing post thawing with day 5, P=0.31. Regarding Annexin level in the study, there was significant increase in day 5, and post thawing as compared with day 0, P= 0.001. Also, there was significant increase in post thawing in comparison with day 5, p= 0.001.We found a significant positive correlations of MPV with time (r= 0.6, p= 0.001), while there was significant negative correlation of platelet count with time (r= -0.458 p=0.001) in different studied groups.
There was significant positive correlation of pH, PO2 and MPV with time, while there was significant negative correlation of PCO2 with MPV (r= -0.745, p=0.001). There was a strong significant negative correlation of both ADP and collagen induced aggregation with 0 to5 days {(r=-0.876, p= 0.001) (r=-0.870, p= 0.001)} and 0 to150 days of storage {(r=0.961, p= 0.001) (r=-0.971, p= 0.001)}.