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Analytical Control
Systems, Inc Analytical Control Systems, Inc. |
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317-841-0458
317-841-3186
Analytical Control Systems, Inc.
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Stored Platelets and Platelet Microparticles: Spectra™ APCT to Test PF3 Activity and Flow Cytometry using Propyl Gallate to Activated Annexin V Qualitative and Quantitative Assessments of Stored Platelets and Platelet Microparticles (PMP): An Activated Plasma Clotting Time (APCT) to Test Platelet Factor 3 (PF3) Activity and a Flow Cytometry Study Using Propyl Gallate to Activate Annexin V By H. Xiao, Methodist Hospital, Indianapolis, IN.
Platelets were activated during storage and one response of the activated platelets was the shedding of PMPs (platelet microparticles) or vesiculation. Platelets and PMPs were the main source of precoagulant phospholipids referred to as PF3. APCT (Activated Plasma Clotting Time [propyl gallate based]) was introduced to detect PF3 and dosage dependent changes were noted for both platelets and PMPs. The decline of single platelets during storage was accompanied with the changes in APCTs of platelet filtrate samples (91.07 ± 1.54 sec. at day 5 to 83.15 ± 2.19 sec. at day 20) and suggests that PF3 and PMPs play roles in the support of coagulation. Platelet storage lesion was also studied by flow cytometry. The percentage of Annexin V-positive platelets at 4º C increased gradually from 1.55 ± 0.84 at day 2 to 78.23 ± 6.16 at day 25 and PMPs with Annexin-V-positive expression (0.33 ± 0.06 at day 1 to 55.86 ± 13.66 at day 25) were seen in a four gated FACScan. PG (propyl gallate) could activate two day old platelets at 93.69 ±3.7 and by removing the spontaneous expression (1.55 ± 0.84), a potential activation (90.02 ± 4.05) was obtained. The responses of storage platelets to PG stimulation varied with the extension of time.
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