Storage of Platelets for Transfusion in Additive Solutions: Effects of Different Factors and Compounds

Abstract

Platelet-additive solution (PAS) can be used as a substitute for plasma for the storage of platelet concentrates (PCs) in order to improve storage conditions, to recover plasma for other purposes, to avoid transfusion of large volumes of plasma to patients, and to make possible photochemical treatment for viral inactivation of PCs. For this reason, PAS should have a great potential for wide use in transfusion medicine. In the studies cited in this review, PCs were prepared from units of whole blood either by the platelet-rich plasma method or the buffy coat method. In some studies, PCs prepared by apheresis were used. The composition of the PASs used varied. The effects on platelet metabolism associated with different factors and compounds in PAS are only partly known. Available studies suggest that: 1) Presence of glucose in the platelet storage medium during the entire storage period is necessary for platelet metabolism. 2) Acetate is used as an additional substrate for platelet metabolism. Acetate also reduces the production of lactate by platelets, and by the formation of bicarbonate it maintains stable pH levels during storage. 3) The fall in pH can be rapid in PAS-containing media due to the very limited buffering capacity of PAS compared with that of plasma. 4) Platelets stored in PAS at a citrate concentration of 8 mmol/l produce only half the quantity of lactate as that of platelets at 14–26 mmol/l of citrate. 5) Free fatty acids from plasma can be used as substrate for platelet metabolism and are supposed to be made available by the hydrolysis of plasma triglycerides. 6) For PCs prepared by apheresis with ACD anticoagulant, presence of phosphate in PAS seems to be a critical factor to avoid low adenine nucleotide levels during storage.

Functional characteristics of buffy‐coat PLTs photochemically treated with amotosalen‐HCl for pathogen inactivation

“…Nevertheless, metabolic studies provide evidence that these substrates alone may not satisfactorily nourish stored PLTs for maintenance of viability 43 . The presence of glucose during the entire storage period is considered to be essential for PLT metabolism 30,39 , 40 and viability 30,43‐46 . Accordingly, our data give evidence that in vitro functionality decreases when the lack of glucose is prolonged over days after complete glucose consumption (see control unit 13 in Table 2 footnote) and is preserved until complete consumption becomes manifest (see the one‐third of test units with complete consumption at the end of storage but still acceptable in vitro functional measures).…”

“…As known from the literature, glucose is not the primary substrate for oxidative metabolism 29 representing the major part (85%) of energy supply in stored PLTs 21,34 . Here, acetate, 34‐38 one of the components of PAS II/III, free fatty acids 34 delivered by the hydrolysis of plasma triglycerides 30,39 , 40 and amino acids 41,42 are mainly entered into the oxidative pathway 43,44 . Nevertheless, metabolic studies provide evidence that these substrates alone may not satisfactorily nourish stored PLTs for maintenance of viability 43 .…”

Storage of platelets in additive solutions: effects of magnesium and/or potassium

“…Future use of PAS in association with photochemical inactivation of virus and bacteria in PCs may accelerate the introduction of PAS on a large scale 4 . Present knowledge of PAS suggests that crucial components in PAS include citrate, acetate, and phosphate 4,7 . Additional components may improve platelet quality after storage.…”

“…Platelet storage media composed of a platelet additive solution (PAS) and a significant proportion (25‐45%) of plasma are in clinical use in Europe for the preparation and storage of platelet concentrates (PCs) obtained from pooled buffy coats (BCs) 1,2 . The characteristics of PAS and the effects on platelet metabolism associated with different components in PAS have been described in several reviews 3‐7 …”