title: Are the reference values of B cell subpopulations used in adults for classification of common variable immunodeficiencies appropriate for children?
abstract: Detailed phenotypic characterization of B cell subpopulations is of utmost importance for the diagnosis and management of humoral immunodeficiencies, as they are used for classification of common variable immunodeficiencies. Since age-specific reference values remain scarce in the literature, we analysed by flow cytometry the proportions and absolute values of total, memory, switched memory and CD21(-/low) B cells in blood samples from 168 healthy children (1 day to 18 years) with special attention to the different subpopulations of CD21(low) B cells. The percentages of total memory B cells and their subsets significantly increased up to 5-10 years. In contrast, the percentages of immature CD21(-) B cells and of immature transitional CD21(low)CD38(hi) B cells decreased progressively with age, whereas the percentage of CD21(low) CD38(low) B cells remained stable during childhood. Our data stress the importance of age-specific reference values for the correct interpretation of B cell subsets in children as a diagnostic tool in immunodeficiencies.
authors.affiliation: Laboratory of Vaccinology and Mucosal Immunity and Immunobiology Clinic, Hôpital Erasme, Université Libre de Bruxelles (U.L.B.), Brussels, Belgium.
authors.forename: J
authors.initials: J
authors.lastname: Smet
authors.forename: F
authors.initials: F
authors.lastname: Mascart
authors.forename: L
authors.initials: L
authors.lastname: Schandené
mesh_terms: D051997:ADP-ribosyl Cyclase 1 / Q000276:immunology; D000293:Adolescent; D018941:Antigens, CD19 / Q000276:immunology; D016175:B-Lymphocyte Subsets / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D017074:Common Variable Immunodeficiency / Q000145:classification* / Q000175:diagnosis / Q000276:immunology; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007231:Infant, Newborn; D018655:Lymphocyte Count; D017464:Receptors, Complement 3d / Q000276:immunology; D012016:Reference Values; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7 / Q000276:immunology
chemical_list: D018941:Antigens, CD19; D017464:Receptors, Complement 3d; D018127:Tumor Necrosis Factor Receptor Superfamily, Member 7; D051997:ADP-ribosyl Cyclase 1