Human recombinant lymphokines and cytokines induce pulmonary eosinophilia in the guinea pig which is inhibited by ketotifen and AH 21-132.

Subcutaneous or intraperitoneal injection of recombinant human granulocyte-macrophage colony-stimulating factor, interleukin 3, or mouse tumour necrosis factor alpha, but not recombinant human interferon gamma, platelet-derived growth factor, or transforming growth factor beta caused selective eosinophilia of the pulmonary airways in the guinea pig. Unlike responses to platelet-activating factor, there was no attendant detectable airway hyperreactivity, but in common with responses to platelet-activating factor, eosinophilia of the airways was prevented by pretreatment with ketotifen or AH21-132. Cytokines or lymphokines may contribute to pulmonary eosinophilia in diseases such as asthma.