Currently, platelet concentrates are stored in 50 to 60 ml of plasma. A major drawback to storage in plasma is the considerable loss of platelet function which occurs during storage. A modified Tyrodes medium has been developed for storage of platelets. A comparison between platelet concentrates stored in this medium and in plasma showed that platelet aggregation and release responses to synergistic pairs of stimuli were equivalent for both types of concentrates on the day of preparation and after 72 hours. Platelet aggregation and release responses to single stimuli, the content of membrane glycoproteins, and the pH declined during storage but were similar for both preparations. The data show that plasma is not required to maintain in vitro platelet function during storage of platelet concentrates, but in vivo functions remain to be determined. The use of an artificial medium has the advantages of decreasing patient exposure to plasma contaminants, generating additional plasma for fractionation, and controlling more exactly the storage environment.

Blood Platelets↗

PubMedDate not supplied

Donor variables affecting survival of autologous platelets.

While platelet survival studies have been carried out by numerous laboratories for many years, general agreement has not been reached on a single method or for the value of this test. Available data indicate that in spite of certain difficulties, reliable comparisons can be obtained using relatively small numbers of donors. Indeed, a difference in platelet survival of as little as 10 percent can be detected by using eight donors, whereas only four donors are required if one wishes to detect a 20 percent change. Should studies be done using donors preselected according to strict criteria of age, sex, health, etc.? It might be that less scatter among the data points would be observed and perhaps even fewer donors would be required to obtain significant values. In surveying the available information, it is clear that many investigators do have data on normal controls which could be extracted and analyzed to provide an answer to this question. Such information would be of great value in determining the criteria for selection of donors for autologous platelet survival studies.

Acute Disease↗

PubMedDate not supplied

Storage of human platelet concentrates in an artificial medium without dextrose.

It was shown previously that human blood platelets stored in an artificial medium (PCD) for up to 5 days remain functional in vitro and have normal survival and recovery in vivo. This report demonstrates that the medium can be simplified further by the removal of dextrose, leaving for study a medium consisting simply of balanced salts and citrate anticoagulant (PC). Some dextrose, 3.2 mM, was present in the fresh PC platelet concentrates due to plasma carryover in the production of platelet concentrates, but this dextrose concentration was considerably less than the 22.6 to 25.5 mM present in platelet concentrates in PCD or plasma. Platelet count, pH, PCO2, and PO2, as well as platelet aggregation and release responses to stimulation, in vitro, were as well preserved in the PCD or PC media as in the plasma controls. In the PC medium, platelets consumed 2.5 mM dextrose over 5 days and left 0.7 mM dextrose. The same consumption of dextrose was noted in PCD platelet concentrates, while platelets in plasma metabolized twice as much dextrose and formed twice as much lactate. Thus, the rate of glycolysis in platelet concentrates was independent of the dextrose concentration in the medium, and the platelet functions were well preserved.

Ammonia↗

PubMedDate not supplied

The effects of irradiation on platelet function.

Current medical practice involves the irradiation of blood components, including platelet concentrates, before their administration to patients with severe immunosuppression. The authors studied the effect of irradiation on in vitro platelet function and the leaching of plasticizers from the bag, both immediately and after 5 days of storage. The platelet count, white cell count, pH, glucose, lactate, platelet aggregation and release reaction, and serotonin uptake were not altered by the irradiation of random-donor or apheresis units with 2000 rads carried out at 0 and 24 hours and 5 days after collection. The leaching of di(2-ethylhexyl)phthalate from the plastic bags followed by the conversion to mono(2-ethylhexyl)phthalate was not increased by irradiation. Therefore, it is possible to irradiate platelet concentrates on the day of collection and subsequently store them for at least 5 days while maintaining in vitro function. This procedure could have considerable benefit for blood banks involved in the provision of many platelet products.

Blood Platelets↗