Depression of T cells in Bell's palsy.

We analyzed T-lymphocytes and their subsets in 20 patients with Bell's palsy. We used the monoclonal antibodies anti-Leu-1, anti-Leu-2a, and anti-Leu-3a directed against T-lymphocytes and T suppressor/cytotoxic (Ts) and T helper/inducer (Th) cell subsets. Blood samples taken in the acute and convalescent phases of the illness were compared. The percentage of T cells (Leu-1+ cells) was decreased during the acute stage, mainly because of a reduction of the Th cell subset (Leu-3+ cells). No significant alteration was found in the Ts cell subset (Leu-2+ cells). The T cell and Th cell subset depressions were restored to normal within 4 to 6 weeks of the onset of the palsy. The T cell changes in the peripheral blood in the acute stage of Bell's palsy indicate the involvement of cellular immune mechanisms.