title: Feasibility of routine ferritin testing for donor management: validation of delayed processing and demonstration of within donor reproducibility over time.
abstract: BACKGROUND
  Understanding the effect of delayed processing of whole blood on plasma ferritin will inform the feasibility of both routine ferritin testing in donors and clinical research study design.
  
  
  METHODS
  Whole blood tubes drawn from 16 donors were held at 4°C and centrifuged at 24-hour intervals to assess plasma ferritin concentration up to 5 days after draw. Intraindividual variation over time was measured in 21 healthy donors in blood samples collected weekly for 4 weeks and then at 12 weeks.
  
  
  RESULTS
  No significant variation in plasma ferritin concentration was observed in blood stored at 4°C for up to 5 days after draw (p = 0.32). The estimated loss of 4.75% ferritin over 5 days was within the reported 5% variation of the assay. Moderate intraindividual variation occurs over time in both sexes, with variability increasing with the mean. No difference was detected between men and women in the regression of standard deviation on mean ferritin (p = 0.43).
  
  
  CONCLUSIONS
  Ferritin is stable in whole blood up to 5 days, demonstrating operational feasibility of its use in monitoring donor iron stores. Moderate fluctuations over time occur, but ferritin measurements are sufficiently reliable to determine donor iron status on the day of donation.
authors.affiliation: Viral Reference Laboratory and Repository Core, Blood Systems Research Institute, San Francisco, California; . mstone@bloodsystems.org.
authors.forename: Mars
authors.initials: M
authors.lastname: Stone
authors.affiliation: RTI International, Rockville, Maryland.
authors.forename: Donald
authors.initials: D
authors.lastname: Brambilla
authors.affiliation: Viral Reference Laboratory and Repository Core, Blood Systems Research Institute, San Francisco, California.
authors.forename: Karla
authors.initials: K
authors.lastname: Murcia
authors.affiliation: Viral Reference Laboratory and Repository Core, Blood Systems Research Institute, San Francisco, California.
authors.forename: Melanie
authors.initials: M
authors.lastname: Dimapasoc
authors.affiliation: Creative Testing Solutions, Tempe, Arizona.
authors.forename: Sherri
authors.initials: S
authors.lastname: Cyrus
authors.affiliation: Connecticut Region, American Red Cross Blood Services, Farmington, Connecticut.
authors.forename: Ritchard G
authors.initials: RG
authors.lastname: Cable
authors.affiliation: Institute for Transfusion Medicine, Pittsburgh, Pennsylvania.
authors.forename: Joseph E
authors.initials: JE
authors.lastname: Kiss
authors.affiliation: Viral Reference Laboratory and Repository Core, Blood Systems Research Institute, San Francisco, California.|University of California at San Francisco, San Francisco, California.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Busch
mesh_terms: D000328:Adult; D001782:Blood Donors; D001793:Blood Preservation / Q000379:methods; D005240:Feasibility Studies; D005260:Female; D005293:Ferritins / Q000097:blood*; D006801:Humans; D008297:Male; D008875:Middle Aged; D011786:Quality Control; D015203:Reproducibility of Results; D013696:Temperature; D013997:Time Factors; D055815:Young Adult
chemical_list: D005293:Ferritins