Article
Increased production of tumor necrosis factor-alpha in whole blood cultures from children with primary malnutrition
Registro en:
AZEVEDO, Z. M. A. et al. Increased production of tumor necrosis factor-alpha in whole blood cultures from children with primary malnutrition. Braz. j. med. biol. res, Ribeirão Preto, SP, v. 38, n. 2, p. 171-183, fev. 2005.
0100-879X
10.1590/S0100-879X2005000200005
Autor
Azevedo, Z. M. A.
Luz, R. A.
Victal, S. H.
Kurdian, B.
Fonseca, V. M.
Fitting, C.
Câmara, F. P.
Haeffner-Cavaillon, N.
Cavaillon, J. -M.
Elsas, Maria Ignez Capella Gaspar
Xavier-Elsas, Pedro Paulo
Resumen
Because low tumor necrosis factor-α (TNF-α) production has been
reported in malnourished children, in contrast with high production of
TNF-α in experimental protein-energy malnutrition, we reevaluated
the production of TNF-α in whole blood cultures from children with
primary malnutrition free from infection, and in healthy sex- and age-
matched controls. Mononuclear cells in blood diluted 1:5 in endo-
toxin-free medium released TNF-α for 24 h. Spontaneously released
TNF-α levels (mean ± SEM), as measured by enzyme immunoassay in
the supernatants of unstimulated 24-h cultures, were 10,941 ± 2,591
pg/ml in children with malnutrition (N = 11) and 533 ± 267 pg/ml in
controls (N = 18) (P < 0.0001). TNF-α production was increased by
stimulation with lipopolysaccharide (LPS), with maximal production
of 67,341 ± 16,580 pg/ml TNF-α in malnourished children and 25,198
± 2,493 pg/ml in controls (P = 0.002). In control subjects, LPS dose-
dependently induced TNF-α production, with maximal responses
obtained at 2000 ng/ml. In contrast, malnourished patients produced
significantly more TNF-α with 0.02-200 ng/ml LPS, responded maxi-
mally at a 10-fold lower LPS concentration (200 ng/ml), and presented
high-dose inhibition at 2000 ng/ml. TNF-α production a) was signifi-
cantly influenced by LPS concentration in control subjects, but not in
malnourished children, who responded strongly to very low LPS
concentrations, and b) presented a significant, negative correlation (r
= -0.703, P = 0.023) between spontaneous release and the LPS
concentration that elicited maximal responses in malnourished pa-
tients. These findings indicate that malnourished children are not
deficient in TNF-α production, and suggest that their cells are primed
for increased TNF-α production.