title: Expression of CD27 and CD23 on peripheral blood B lymphocytes in humans of different ages.
abstract: BACKGROUND
  Due to the fact that the coexpression of CD23 and CD27 has been reported to occur in B lymphocytic leukaemic clones and that there is debate about CD23 expression on memory B cells, we evaluated the behaviour of naive B cells (CD23-/CD27-) and memory B cells (CD27+) in the peripheral blood of a large number of humans of all ages. B cells were also distinguished into B2 (CD5-) and B1-a cells (CD5+).
  
  
  METHODS
  The cell surface expression of CD19, CD5, CD23 and CD27 was assessed on peripheral blood lymphocytes from 1,427 subjects of all ages undergoing peripheral blood immunophenotyping for a variety of reasons.
  
  
  RESULTS
  The absolute number of B lymphocytes and the percentage of naive cells (CD23-/CD27-) decreased with age whereas there was an increase in memory cells (CD27+). A small subset of B cells co-expressing CD23 and CD27 was present in humans of all ages, although the majority of CD27+ cells were CD23-. The percentages and rate of increase with age of B1-a CD23+/CD27+ were slightly higher than those of B2 cell counterparts.
  
  
  CONCLUSIONS
  On the basis of our data, age-associated changes in surface markers of B cells seem to be finely balanced and probably related to functional changes after antigen encounters, while the whole peripheral blood B-cell compartment undergoes a quantitative regression.
authors.affiliation: Dipartimento di Medicina Clinica e Sperimentale, Sezione di Ematologia, Università di Verona, Italia. dino.veneri@univr.it
authors.forename: Dino
authors.initials: D
authors.lastname: Veneri
authors.forename: Riccardo
authors.initials: R
authors.lastname: Ortolani
authors.forename: Massimo
authors.initials: M
authors.lastname: Franchini
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Tridente
authors.forename: Giovanni
authors.initials: G
authors.lastname: Pizzolo
authors.forename: Antonio
authors.initials: A
authors.lastname: Vella
mesh_terms: D000375:Aging; D018941:Antigens, CD19 / Q000235:genetics / Q000276:immunology; D016175:B-Lymphocyte Subsets / Q000166:cytology* / Q000276:immunology*; D018956:CD5 Antigens / Q000235:genetics / Q000276:immunology; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D017455:Receptors, IgE / Q000235:genetics* / Q000276:immunology; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000235:genetics* / Q000276:immunology
chemical_list: D018941:Antigens, CD19; D018956:CD5 Antigens; D017455:Receptors, IgE; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7