TNF-alpha, leptin, and lymphocyte function in human aging.
Aging is associated with increased inflammatory activity and concomitant decreased T cell mediated immune responses. Leptin may provide a link between inflammation and T cell function in aging. The aim of the study was to investigate if plasma levels of tumor necrosis factor (TNF)-alpha were associated with leptin, circulating interleukin-2 receptors (sIL-2R), and phytohaemagglutinin (PHA) induced IL-2 production in whole blood in elderly humans. Circulating levels of TNF-alpha and sIL-2R were higher in elderly humans (N=42) compared to a young control group (N=37) whereas there was no difference with regard to IL-2 production. Furthermore, there were no age-related differences in serum levels of leptin. However, women had higher levels than men. In the elderly people, serum levels of leptin were correlated with TNF-alpha in univariate regression analysis and in a multiple linear regression analysis adjusting for the effect of gender and body mass index. Furthermore, TNF-alpha, but not leptin, was positively correlated to sIL-2R and negatively correlated to IL-2 production. In conclusion, increased plasma levels of TNF-alpha in aging is associated with poor IL-2 production ex vivo and lymphocyte activation in vivo. These associations do not seem to involve leptin.
Bruunsgaard
H
H
Department of Infectious Diseases, Rigshospitalet, University of Copenhagen, Denmark. infdishb@rh.dk
Pedersen
A N
AN
Schroll
M
M
Skinhøj
P
P
Pedersen
B K
BK
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000097:blood* / Q000276:immunology*; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D005260:Female; D006801:Humans; D007376:Interleukin-2 / Q000097:blood; D020738:Leptin / Q000097:blood*; D007958:Leukocyte Count; D008213:Lymphocyte Activation; D018655:Lymphocyte Count; D008297:Male; D015375:Receptors, Interleukin-2 / Q000097:blood; D054411:Receptors, Leptin; D012044:Regression Analysis; D012727:Sex Characteristics; D013601:T-Lymphocytes / Q000276:immunology*; D014409:Tumor Necrosis Factor-alpha / Q000032:analysis*
D007376:Interleukin-2; C515448:LEPR protein, human; D020738:Leptin; D015375:Receptors, Interleukin-2; D054411:Receptors, Leptin; D014409:Tumor Necrosis Factor-alpha