[Production and inhibition of eosinophil colony stimulating factor by lymphocytes from patients with bronchial...

To clarify the mechanism of the eosinophilia in patients with bronchial asthma (BA), we examined the production and inhibition of eosinophil colony stimulating factor (Eo-CSF) of mononuclear cells (MNC) and lymphocytes from BA. After bone marrow cells from normal volunteers (NA) were incubated with culture media of MNC or lymphocytes cultured in the presence of interleukin-2 (IL-2, 1 U/ml) or Dermatophagoides farinae (10 micrograms/ml, Df), the number of eosinophils was increased and GM-CSF production was increased after 5 days of culture. Interleukin 5 (IL-5) production was increased in some cases of BA, but did not differ between BA and NA delete. When MNC were incubated in the presence of IL-2 and interleukin 4 (IL-4), neither eosinophilia nor GM-CSF production occurred. These results suggest first that MNC and T cells in BA have increased responsiveness to IL-2 and Df, second that increased GM-CSF production partly causes eosinophilia, and third that IL-4 inhibited IL-2-induced eosinophil proliferation by inhibition of GM-CSF production.