Activated T cells and Leu-7+ cells in Bell's palsy.

Patients with Bell's palsy were investigated with regard to the cellular immune response during the acute and convalescent stages with the purpose of acquiring information concerning the etiology of the condition. In order to ascertain whether there was activation of the immune system, the proportion of activated T cells in the peripheral blood of 14 patients with Bell's palsy was analysed using monoclonal antibodies. A transient increase of these cells occurred in the acute stage, with a return to normal in the convalescent stage. The Leu-7+ cells which play a role in the natural cellular defence against viral infections, were also studied by using monoclonal antibodies in 25 patients. A significant change in the percentage of Leu-7+ cells was not found when the samples from the entire group were analysed. However, 10 patients who were investigated between September and October 1984, when the incidence of Bell's palsy was comparatively high, showed significantly lower percentages of Leu-7+ cells in the acute stage compared with the convalescent stage. The increase in the activated T cells in the acute phase of the palsy suggests a cell-mediated, immuno-regulatory abnormality with primary or secondary immune activation. Similar cellular immune alterations are found also in multiple sclerosis. Further, the differences in the proportions of Leu-7+ cells which occurred in these 10 patients may denote a contribution of various etiological factors to the disease.