Factors Influencing Changes in pH during Storage of Platelet Concentrates at 20-24 °C

Abstract

The magnitude of the pH change during platelet concentrate storage at 20-24 °C in polyvinyl chloride containers is not determined solely by platelet count per cubic millimeter of plasma, since a wide variation in pH was observed with similar platelet concentrations. In modified platelet concentrates having lost through centrifugation 3-15% of total platelets and 61-92% of residual leukocytes, the pH was maintained at substantially higher levels than in the paired control platelet concentrates. Leukocyte levels do not appear to determine the magnitude of the pH fall. Continuous oxygen ulilization is needed if the pH is to be maintained near 7.0. However, oxygen tension per se is not the factor which influences the extent of pH change. It has been concluded that a specific platelet subpopulation comprising a small proportion of the total platelets in concentrates and having an enhanced capacity to form lactate may be responsible for a major part of the pH reduction which occurs during storage of many platelet concentrates.

Effect of phospholipase C (Bacillus cereus) on freshly isolated and 4-day-stored human platelets

“…Platelets from 4-day-stored concentrates were attacked by phospholipase C to an extent which correlated with the pH of the concentrate at day 4. The pH after storage is determined by the platelet count of the concentrate (Murphy & Gardner, 1975;Slichter & Harker, 1976;Moroff et al, 1982; also confirmed in the present study). Platelets from stored concentrates of final pH 6.5-6.9 suffered a 10-1 5% degradation ofphospholipid.…”

High‐yield Platelet units revealed immediate pH decline and delayed mitochondrial dysfunction during storage in 100% plasma as compared with storage in SSP+

“…However, sufficient oxygen supply seems to be a key factor in the maintenance of oxidative phosphorylation necessary for adequate ATP production/levels [16–19]. Previous studies have also reported various plasters and plasticizers permeability to gases [19–21], high PLT counts, carbon dioxide/oxygen levels [18, 22] and mitochondrial dysfunction [23, 24] as factors important for the maintenance of PLT quality during storage. These results illustrate the complexity of the underlying mechanisms leading to reduced PLT viability.…”

Alternative methods of platelet storage and pathogen reduction

“…PLT preparation and storage processes induce the shedding of microparticles that promote thrombosis [4]. During storage, increased glycolysis and reduced mitochondrial function result in glucose depletion, lactic acid accumulation and a fall in pH [5]. The greater the lactic acid production and pH decline, the lower the PLT life span and recovery in the human organism [6].…”