title: The value of pH as a quality control indicator for apheresis platelets.
abstract: BACKGROUND
  Standards and regulations require measurement of pH as an apheresis platelet (PLT) component quality monitor. The usefulness of this quality control (QC) measure was investigated.
  
  
  METHODS
  QC data were retrospectively reviewed for apheresis PLTs collected over 4.5 years. Three collection devices were used, the Amicus (Baxter), the CS-3000 Plus (Baxter), and the MCS+ LN9000 (Haemonetics). Each month, four components from each instrument were sampled. PLT counts and component volume were measured immediately after collection, and pH, after 5 days of storage.
  
  
  RESULTS
  A total of 668 products were studied. pH decreased as PLT concentration increased (r(2) = 0.129, p < 0.001) and as component volume decreased (r(2) = 0.086, p = 0.02). PLT concentration and volume, however, were poor predictors of a low pH. Apheresis instrument type affected pH. The 216 components collected with use of the CS-3000 device had a lower pH than components from the other two instruments. Only 13 components had a pH value less than the acceptable level of 6.2, 12 of which were collected with the CS-3000.
  
  
  CONCLUSIONS
  For newer-model blood cell separators, pH measurements do not provide information that might identify a manufacturing problem. Because factors that influence pH are controlled or monitored for each component, evaluation of pH on a sample group provides an indication of the quality of specific component only, rather than an effective monitor of the quality of the manufacturing process.
authors.affiliation: From the Department of Transfusion Medicine, Warren G. Magnuson Clinical Center, National Institutes of Health, Bethesda, Maryland.
authors.forename: Cynthia
authors.initials: C
authors.lastname: Tudisco
authors.forename: Betsy W
authors.initials: BW
authors.lastname: Jett
authors.forename: Karen
authors.initials: K
authors.lastname: Byrne
authors.forename: Jaime
authors.initials: J
authors.lastname: Oblitas
authors.forename: Susan F
authors.initials: SF
authors.lastname: Leitman
authors.forename: David F
authors.initials: DF
authors.lastname: Stroncek
mesh_terms: D001771:Blood Banks / Q000592:standards; D001781:Blood Component Removal / Q000379:methods / Q000592:standards*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010976:Platelet Count; D010983:Plateletpheresis / Q000379:methods / Q000592:standards*; D011786:Quality Control; D012189:Retrospective Studies