title: Effect of blood donation on the establishment of normal ranges of lymphocyte subsets.
abstract: BACKGROUND
  Absolute counts of CD4+ T-lymphocytes are used in the management of patients with human immunodeficiency virus infection. Low absolute counts of CD3+CD4+ cells have also been observed in healthy people--a phenomenon called idiopathic CD4 lymphocytopenia. It is common practice for normal ranges for lymphocyte subsets to be derived from samples taken from blood donors.
  
  
  METHODS
  A sample of EDTA blood was taken through the donation line tubing, after donation from 565 blood donors in Sydney, Australia, who were selected from a range of age groups. An additional 12 donors provided a predonation sample as well as a postdonation sample. Hematologic assays were performed on two analyzers. Samples were stained for CD3, CD4, CD8, CD19, and CD56 and analyzed on a flow cytometer.
  
  
  RESULTS
  Three donors were found to have absolute CD3+CD4+ counts < 300 cells per microL. The percentage of CD3+CD4+ cells was found to increase with age. Both the percentage and the absolute count of CD3+CD8+ cells decreased with age, which resulted in an increased CD4:CD8 ratio with age. Men had consistently higher absolute counts of CD3-CD56+ cells than women. The 12 additional donors all had greater percentages of CD3+CD4+ cells and lower absolute counts for CD3+, CD3+CD4+, CD3+CD8+, CD19+ and CD3-CD56+ cells after donation than they had before donation (p < 0.001).
  
  
  CONCLUSIONS
  It is not satisfactory to base normal ranges for lymphocyte subsets on donor blood, from which the blood sample has been obtained after donation.
authors.affiliation: New South Wales Red Cross Blood Transfusion Service, Sydney, Australia.
authors.forename: J A
authors.initials: JA
authors.lastname: Bryant
authors.forename: B R
authors.initials: BR
authors.lastname: Wylie
authors.forename: F F
authors.initials: FF
authors.lastname: Yuan
authors.forename: A
authors.initials: A
authors.lastname: Ribeiro
authors.forename: A R
authors.initials: AR
authors.lastname: Thomson
authors.forename: M A
authors.initials: MA
authors.lastname: Cooley
authors.forename: A
authors.initials: A
authors.lastname: Fletcher
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018941:Antigens, CD19 / Q000032:analysis; D001782:Blood Donors; D017252:CD3 Complex / Q000032:analysis; D018791:CD4 Lymphocyte Count; D019002:CD56 Antigen / Q000032:analysis; D018414:CD8-Positive T-Lymphocytes; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D018655:Lymphocyte Count; D016131:Lymphocyte Subsets; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D012907:Smoking / Q000097:blood
chemical_list: D018941:Antigens, CD19; D017252:CD3 Complex; D019002:CD56 Antigen