Studies of human lymphocytes in the newborn and the aged.
Proportions and absolute numbers of T and B lymphocytes were determined among 30 newborn infants and group of 77 elderly patients 60 to 95 years of age. Total lymphocytes in the cord blood of the newborn showed a distinct elevation in total numbers of T and B lymphocytes (p less than 0.005) as compared to that in blood from normal adult controls, reflecting the relative lymphocytosis of infancy. Proportions of cord blood T lymphocytes as reflected by the sheep cell rosette technic were considerable lower than those in lymphocytes from normal adult controls, however, proportions of cord blood T lymphocytes as determined by indirect immunofluorescence were not significantly different from those in controls. Old people showed a significant reduction in total numbers of lymphocytes (p less than 0.005) when compared with those in normal adult controls 18 to 51 years of age. Moreover, there was a significant increase in the relative proportions of peripheral blood B lymphocytes in the elderly although the absolute numbers of B lymphocytes in the elderly although the absolute numbers of B cells did not differ from those in younger controls. A significant decrease in total numbers of T cells as measured both by sheep cell rosettes and indirect immunofluorescence was recorded among older patients (p less than 0.001). In addition, there was a broad increment in the incidence of various autoantibodies (anti-nuclear, andi-IgG, antismooth muscle, antimitochondrial and antiparietal cell) among the old people studies. No direct correlation could be determined between relative B-cell percentage increase or T-cell decrease and the presence of various autoantibodies in individual patients. Diminution in total lymphocyte counts as well as absolute numbers of T cells in the elderly may provide the cellular basis for an increased susceptibility to neoplasia and infection.
D000293:Adolescent; D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000032:analysis; D001402:B-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000648:ultrastructure; D002452:Cell Count; D005260:Female; D005312:Fetal Blood / Q000166:cytology / Q000276:immunology; D005455:Fluorescent Antibody Technique; D006801:Humans; D007104:Immune Adherence Reaction; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D013601:T-Lymphocytes / Q000166:cytology* / Q000276:immunology / Q000648:ultrastructure
D001323:Autoantibodies