Lymphocyte subsets in infants: relationships to feeding, atopy, atopic heredity and infections

Numbers of T and B lymphocytes and T cell subsets were measured longitudinally in blood samples of 68 healthy infants from 1 month to 28 months of age. Monoclonal antibodies against cell surface antigens (OKT3, OKT4, OKT8, and OKIal) and antibodies to immunoglobulin heavy chains (gamma, mu, alpha and delta) were used for immunofluorescent staining. The absolute number of T lymphocytes (OKT3) was found to be highest at the age of 6-7 months, reflecting the greater numbers of both helper (OKT4) and suppressor (OKT8) cells. The percentages of OKT4 and OKT8 positive cells and hence the ratios of these cells were very stable throughout the study period. Relatively, breast-fed infants had more suppressor (OKT8) cells than infants on formula, but the difference was not apparent in absolute counts. Change to formula feeding caused an increase in B cells. The heredity for atopy did not influence the total numbers of T cells or cell numbers in the different subgroups. At the age of 4 months an altered helper/suppressor ratio was noted in infants who later developed a severe atopy. At the age of 28 months the relative number of T cells was lower in atopic than nonatopic infants. The rate of respiratory infections did not affect these numbers.