@article{084b31701a4711df8ed1000ea68e967b,
title = "High circulating levels of tumor necrosis factor-alpha in centenarians are not associated with increased production in T lymphocytes",
abstract = "BACKGROUND: Aging is characterized by increased inflammatory activity reflected by increased plasma levels of proinflammatory cytokines, concomitant with an altered cytokine profile of T lymphocytes. High plasma levels of tumor necrosis factor (TNF)-alpha are strongly associated with morbidity and mortality in elderly humans. However, the cellular source and mechanisms for the increased circulating TNF-alpha levels are unknown. OBJECTIVE: The aim of the present study was to investigate if high plasma levels of TNF-alpha are associated with increased production of TNF-alpha by T lymphocytes in elderly humans. METHODS: TNF-alpha production by CD4+ and CD8+ T lymphocytes was measured by flow cytometry following stimulation with phorbol 12-myristate 13-acetate and ionomycin in 28 young controls, 14, 81-year-olds and 25 centenarians. RESULTS: Plasma levels of TNF-alpha increased with increasing age. An increased percentage and number of T lymphocytes from the 81 year olds expressed TNF-alpha, whereas centenarians did not show this altered TNF-alpha secretion profile. CONCLUSION: T cells may contribute to the elevated levels of plasma TNF-alpha in healthy elderly subjects, whereas other mechanisms are responsible in very old individuals.",
author = "Marie Sandmand and Helle Bruunsgaard and K{\aa}re Kemp and Karen Andersen-Ranberg and Marianne Schroll and Bernard Jeune",
note = "Keywords: Adult; Aged; Aged, 80 and over; Female; Humans; Lymphocyte Activation; Male; T-Lymphocytes; Tumor Necrosis Factor-alpha",
year = "2003",
doi = "10.1159/000069174",
language = "English",
volume = "49",
pages = "155--60",
journal = "Gerontology",
issn = "0304-324X",
publisher = "S Karger AG",
number = "3",
}