title: Age-related changes in blood lymphocyte subsets of Saudi Arabian healthy children.
abstract: The age-related changes in absolute and percentage values of lymphocyte subsets in the peripheral blood of healthy children of different ages (1 month to 13 years) were studied by flow cytometry. The absolute and percentage values for most lymphocyte subpopulations differed substantially with age. Comparisons among age groups from infants through adults revealed progressive declines in the absolute numbers of leukocytes, total lymphocytes, and T, B, and natural killer (NK) cells. The percentages of T cells increased with age. Within the T-lymphocyte population, the CD8(+) subset increased but the CD4(+) subset decreased, resulting in a declining CD4(+)/CD8(+) ratio. The percentage of B cells declined, but that of NK cells remained unchanged. The percentage of HLA-DR+ T cells increased over time, but their number changed inconsistently. Our findings confirm and extend earlier reports on age-related changes in lymphocyte subpopulations. These data should be useful in the interpretation of disease-related changes, as well as therapy-dependent alterations, in lymphocyte subsets in children of different age groups.
authors.affiliation: Division of Immunology, Department of Pathology, College of Medicine and King Khalid University Hospital, King Saud University, Riyadh 11461, Kingdom of Saudi Arabia. shahab@welchlink.welch.jhu.edu
authors.forename: S
authors.initials: S
authors.lastname: Shahabuddin
authors.forename: I
authors.initials: I
authors.lastname: Al-Ayed
authors.forename: M O
authors.initials: MO
authors.lastname: Gad El-Rab
authors.forename: M I
authors.initials: MI
authors.lastname: Qureshi
mesh_terms: D000293:Adolescent; D000328:Adult; D000375:Aging / Q000502:physiology*; D000911:Antibodies, Monoclonal; D001402:B-Lymphocytes / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D005260:Female; D005434:Flow Cytometry; D006801:Humans; D016130:Immunophenotyping; D007223:Infant; D007694:Killer Cells, Natural / Q000502:physiology; D007962:Leukocytes / Q000502:physiology; D016131:Lymphocyte Subsets / Q000145:classification / Q000502:physiology*; D008297:Male; D012016:Reference Values; D012529:Saudi Arabia; D013601:T-Lymphocytes / Q000502:physiology
chemical_list: D000911:Antibodies, Monoclonal