Pooled Platelet Concentrates Prepared by the Platelet‐Rich‐Plasma Method and Filtered with Three Different Filters and Stored for 8 Days

Abstract

Pooled platelet concentrates (PC) prepared by the platelet-rich plasma (PRP) method were filtered with three different filters and stored for 8 days at room temperature. The effect of filtration on leukocyte contamination, platelet concentration, and the in vitro function, morphology, metabolism and activation of platelets were studied. Eight pools of 20 PRP-PC were used, each pool was split into 4 equal volumes; 3 were filtered over a PL50HF, a PL-10A and a Bio P10 filter, the 4 served as a control. After filtration, leukocyte counts exceeded 3 x 10(5) in none of the pooled PC. Platelet loss induced by filtration was about 17%. During storage, no differences in pH, PCO2, and lactate and glucose concentration were found between the filtered and the unfiltered units, nor were any differences observed between filtered and unfiltered pooled PC in aggregation upon stimulation with collagen and/or ADP, adhesion capacity to collagen in flowing blood, nucleotide content of the platelets and nucleobase concentration in the plasma, expression of activation-dependent antigens, or platelet morphology as observed by light microscopy and by the swirling effect. Selective removal of beta-thromboglobulin (22%) by the PL50HF filter was observed. Pooled PC prepared by the PRP-method can be filtered and stored for 8 days without detrimental effect on platelet function, metabolism or activation.

Prevention of Cytokine Accumulation in Platelets Obtained with the COBE Spectra Apheresis System

“…By comparison, from day 0 to day 7 we found an increase of P-selectin expression from 32.9 to 54.6% in PCs recovered from WB and from 7.2 to 45.9% in LR PCs (table 3). In another study, LR PCs prepared from platelet-rich plasma (PRP) were also found to express increasing levels of P-selectin from 1 to 8 days of storage (17–45%) [49]. Sweeney et al [50]also showed similar levels of P-selectin expression after 5 days storage of apheresis platelets whether unfiltered (39%) or filtered (43%) before storage.…”

The quality of platelets after storage for 7 days

“…GPIb (CD42b) is a platelet receptor for von Willebrand factor (vWF), which under conditions of high shear rate facilitates adhesion of platelets to the subendothelium through the interaction of vWF and collagen. Some studies report little change in the percentage of platelets expressing GPIb during storage of PCs for 7–9 days (Sarraj‐Reguieg et al ., 1993; Boomgaard et al ., 1995; Ferrer et al ., 2000a), whilst others show a decrease of 5–30% over this time period (George et al ., 1988; Garcia et al ., 1992; Metcalfe et al ., 1997; Ferrer et al ., 2000b). Loss of GPIb expression during storage of PCs is likely to be due to proteolytic cleavage, because levels of glycocalicin in the supernatant also increase (Michelson et al ., 1988).…”

“…When platelets become activated, there is a conformational change in GPIIb/IIIa (CD41/CD61), enabling binding of fibrinogen and vWF, a key mechanism in promoting platelet–platelet aggregation. Most studies have shown that expression of GPIIb/IIIa does not alter throughout storage of PCs to days 7–9 (Sarraj‐Reguieg et al ., 1993; Metcalfe et al ., 1997; Ferrer et al ., 2000a,b), is similar in PRP, BC or apheresis PC (Metcalfe et al ., 1997) and is not influenced by leucodepletion (Boomgaard et al ., 1994c, 1995). However, this provides little information on whether there are any changes in the function of this receptor, i.e.…”

“…Only small changes in the ability of platelets to bind to fibrinogen or collagen are observed under conditions of flow in vitro in BC PC over 8 days of storage (Boomgaard et al ., 1994c). Other studies have shown for both BC and PRP PC that adhesion to collagen is reduced to around 80–85% of day 1 values at day 7/8 (Boomgaard et al ., 1994a, 1995) and platelet adhesion to subendothelial matrix is 65% at day 3 and 45% at day 7 compared to day 1 values (Boomgaard et al ., 1994a). The latter study also showed a decline in the aggregatory response to collagen during PC storage.…”

Characterization of blood components prepared from whole‐blood donations after a 24‐hour hold with the platelet‐rich plasma method

“…A few studies have addressed the effect of an extended WB storage time at room temperature before component preparation with the PRP method 14‐22 . The aim of this work was to evaluate the impacts of an overnight hold of WB donations on blood components processed with the PRP method.…”