Immunophenotyping of blood lymphocytes at birth, during childhood, and during adulthood in HIV-1-uninfected Ethiopians

• Published in: Clinical immunology (Orlando, Fla.) Vol. 109; no. 3; pp. 338 - 346
• Main Authors: Tsegaye, Aster, Wolday, Dawit, Otto, Sigrid, Petros, Beyene, Assefa, Tsehai, Alebachew, Tsegaye, Hailu, Ermias, Adugna, Fekadu, Measho, Worku, Dorigo, Wendelien, Fontanet, Arnaud L, Baarle, Debbie van, Miedema, Frank
• Format: Journal Article
• Language: English
• Published: San Diego, CA Elsevier Inc 01.12.2003; Elsevier
• Subjects: Adolescent; ADP-ribosyl Cyclase - blood; ADP-ribosyl Cyclase 1; Adult; Africa; Aging - blood; Antigens, CD - blood; B-Lymphocytes - cytology; B-Lymphocytes - immunology; Biological and medical sciences; CD3 Complex - blood; CD4 antigen; CD4 counts; CD4-CD8 Ratio; CD4-Positive T-Lymphocytes - cytology; CD4-Positive T-Lymphocytes - immunology; CD56 Antigen - blood; CD8-Positive T-Lymphocytes - cytology; CD8-Positive T-Lymphocytes - immunology; Child; Child, Preschool; Cohort Studies; Ethiopia; Flow Cytometry; Fundamental and applied biological sciences. Psychology; Fundamental immunology; histocompatibility antigen HLA; HLA-DR Antigens - blood; Human immunodeficiency virus; Humans; Immune activation; Immunobiology; Immunophenotyping; Infant, Newborn; Killer Cells, Natural - cytology; Killer Cells, Natural - immunology; Leukocyte Count; Lymphocyte Activation - immunology; Lymphocyte subsets; Lymphocyte Subsets - immunology; Lymphoid cells: ontogeny, maturation, markers, receptors, circulation and recirculation; Membrane Glycoproteins; Neonates; Receptors, IgG - blood; Tropical medicine; Ethiopia; Africa; Neonates; Immune activation; Lymphocyte subsets; CD4 counts; Ethiopia; Africa; Human; Immunophenotype; Biological marker; Immunology; T-Lymphocyte; Differentiation; Lymphocyte; Age
• ISSN: 1521-6616; 1521-7035
• DOI: 10.1016/j.clim.2003.08.008

To obtain more insight into blood lymphocyte subpopulations of Ethiopians, we studied the immunologic profile of children and neonates and compared these data with those obtained from adults. Peripheral blood mononuclear cells (PBMCs) and cord blood mononuclear cells (CBMCs) were collected from 137 HIV-1-uninfected subjects aged 0 (cord blood) up to 40 years. Lymphocyte subsets (T, B, and NK cells, CD4 + and CD8 + T cells) were determined and T cell activation (CD38 and HLA-DR) and differentiation (CD45RO and CD27) markers were measured on CD4 + and CD8 + T cells. The absolute number and percentage values of most lymphocyte subpopulations differed substantially with age. Neonates and children were found to have significantly higher CD4 + T cell counts compared to adults. The median absolute CD4 count at birth was comparable to those reported for Caucasians. At birth 97% of the CD4 + T cells were naîve and this proportion significantly declined to 14.2% during adulthood. In addition, activation of both CD4 + and CD8 + T cells, as determined by the double expression of HLA-DR and CD38, was observed in children under the age of 16 and adults, but not in neonates. A more differentiated phenotype (CD27 −) was observed in adults compared to children for both CD4 + and CD8 + T cells. The immune alterations including the remarkably low CD4 count with highly depleted naîve phenotype and a persistently activated immune system seen in adult Ethiopians are not apparent at birth, but rather develop over time.