Proliferative response of blood cells of patients with myasthenia gravis to purified mammalian acetylcholine receptor.

We employed a purified mammalian (fetal calf) acetylcholine receptor (AChR) preparation to compare proliferation of peripheral blood mononuclear cells (PBMC) of patients with myasthenia gravis (MG) (n = 8) and normal controls (n = 6). PBMC of patients with MG demonstrated an enhanced proliferative response to AChR when compared to controls (mean stimulation index (SI) of 4.2 +/- 1.5 (SD) vs. 1.1 +/- 0.6; p less than 0.01) but no difference in the response to tetanus toxoid (7.1 +/- 3.9 vs. 11.1 +/- 10.8). These results suggest that MG patients exhibit a presumptive T-cell response to purified mammalian AChR that is not found in normal subjects. The nature of the proliferating cell and the interaction with B cells producing anti-AChR antibodies remain to be determined.