Inhibition of Histamine and Prostaglandin D ₂ Release from Human Lung Mast Cells by Ciclosporin A

Cyclosporin A (CsA) is now widely used in the prevention/treatment of graft rejection and in the treatment of some human inflammatory diseases. We studied the effect of CsA on the release of chemical mediators from human lung mast cells in vitro. CsA (0.03-3 micrograms/ml) inhibited the release of histamine and prostaglandin D2 induced by anti-IgE from lung mast cells. CsA-induced inhibition of mediator release was not abolished by washing the cells before stimulation and it was not affected by the degree of purity of mast cell preparations. Our results indicate that CsA, in pharmacological concentrations, is a rapid and irreversible inhibitor of the release of preformed and de novo synthesized mediators from human lung mast cells. These findings might explain, at least in part, some of the therapeutic actions of CsA in vivo.