Inhibitory effect of lidocaine on T cells from patients with allergic asthma.

Abstract

Nebulized lidocaine enables dosages of oral corticosteroids to be tapered in the treatment of severe asthma. We sought to investigate the effect of lidocaine on T cells from patients with allergic asthma. PBMCs and CD4(+) T cells were isolated from 6 patients with asthma and house dust mite allergy. PBMCs were cultured with lidocaine for up to 7 days and then stained with propidium iodide to evaluate the involvement of apoptosis. In addition, the viability of CD4(+) T cells when cultured with lidocaine was investigated. Effects of lidocaine on proliferative response, mRNA expression, and protein production of IL-5 and IFN-gamma by PBMCs were investigated after stimulation with Dermatophagoides farinae, purified protein derivative, and phorbol 12-myristate 13-acetate plus calcium ionophore. The effects of lidocaine on the proliferative response of steroid-insensitive PBMCs from 6 nonallergic donors induced by preculture with IL-2 and IL-4 were also investigated. No significant increase in the staining of PBMCs with propidium iodide was observed in the presence of 100 micromol/L lidocaine. The viability of CD4(+) T cells was not significantly affected by culture with lidocaine at this concentration. However, lidocaine inhibited, in a dose-dependent manner, the proliferative response and mRNA expression and protein production of IL-5 and IFN-gamma of PBMCs stimulated with D farinae, purified protein derivatives, or phorbol 12-myristate 13-acetate plus calcium ionophore. Preincubation of PBMCs with IL-2 and IL-4 significantly decreased the inhibitory effects of both corticosteroids and lidocaine compared with that after preincubation with medium alone. Lidocaine has immunoregulatory effects on T cells. Therefore, lidocaine might be studied as an anti-inflammatory agent in the treatment of severe steroid-dependent asthma.