Leukocytes from wheezing infants release lower amounts of IL-12 and IFN-γ compared to non-wheezing infants.
OBJECTIVE
This study investigated environmental endotoxin exposure during early life, sensitization to aeroallergens, the production of cytokines by LPS-stimulated leukocytes, and the development of a wheezing phenotype in a prospective cohort of infants with high risk of developing allergic diseases.


METHODS
Eighty-four infants were followed from birth until 30 months of age. We assessed endotoxin concentration in house dust of their homes during the first 6 months of life. At age 30 months they were clinically evaluated to determine the development of wheezing and other clinical events, were skin prick tested, and had blood samples collected for the evaluation of cytokine release by LPS-stimulated peripheral blood mononuclear cells (PBMC).


RESULTS
The level of endotoxin exposure during early life was not associated with development of a wheezing phenotype. On the other hand a higher incidence of respiratory infections occurred among recurrent wheezing (RW) infants. PBMC from RW children exposed to higher levels of environmental endotoxin (above 50 EU/mg) released less Interleukin (IL)-12p70 and IFN-γ compared to the non-RW group. TNF-α, IL-10, IL-4, IL-5, and IL17 production by LPS-stimulated PBMC from RW and non-RW children was equivalent in both groups of environmental endotoxin exposure.


CONCLUSIONS
In this prospective cohort of infants with high risk of developing allergic diseases we observed that RW and non-RW children were exposed to similar levels of endotoxin early in life. LPS-stimulated PBMC from RW infants exposed to higher levels of endotoxin released significantly less IL-12 and IFN-γ compared to non-RW infants.
Department of Immunology, Institute of Biomedical Sciences, University of São Paulo, São Paulo-SP, Brazil.
Angela
A
Falcai
Paulo Vítor Soeiro
PV
Pereira
Christina Arslanian
CA
Kubo
Vera
V
Rullo
Paolo Rugero
PR
Errante
Dirceu
D
Solé
Antonio
A
Condino-Neto
D002478:Cells, Cultured; D002675:Child, Preschool; D016207:Cytokines / Q000276:immunology; D004391:Dust / Q000276:immunology; D004731:Endotoxins / Q000276:immunology; D005260:Female; D006801:Humans; D015994:Incidence; D007223:Infant; D007371:Interferon-gamma / Q000378:metabolism*; D018664:Interleukin-12 / Q000378:metabolism*; D007963:Leukocytes, Mononuclear / Q000276:immunology*; D008070:Lipopolysaccharides / Q000494:pharmacology; D008297:Male; D011446:Prospective Studies; D012135:Respiratory Sounds / Q000175:diagnosis / Q000276:immunology*; D012141:Respiratory Tract Infections / Q000276:immunology; D012882:Skin Tests
D016207:Cytokines; D004391:Dust; D004731:Endotoxins; D008070:Lipopolysaccharides; D018664:Interleukin-12; D007371:Interferon-gamma