Elevated production of GM-CSF by peripheral blood mononuclear cells stimulated with mite antigens in children with bronchial asthma]

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine which can stimulate the proliferation and functions of eosinophils and neutrophils. We have studied whether peripheral blood mononuclear cells (PBMC), obtained from children with stable asthma, can produce GM-CSF through stimulation with crude Dermatophagoides farinae (Df) antigen in vitro. The patients had strongly positive RAST results for house dust mite Df. Levels of GM-CSF in PBMC culture supernatant were assayed by an enzyme immunoassay. When stimulated with Df antigen, patient's PBMC released significantly increased levels of GM-CSF compared with unstimulated ones. PBMC of non-allergic controls, however, did not. The addition of polymyxin B, an inactivator of endotoxin, did not suppress the Df-antigen-induced production of GM-CSF. Levels of GM-CSF produced by PBMC stimulated with Df antigens were significantly higher in the patients than in the controls. These results indicate that PBMC of children with Df-allergic asthma, unlike those of non-allergic children, can produce elevated levels of GM-CSF by stimulation with Df antigens.