Dynamic expression of B7∶CD28/CTLA4 costimulatory molecules on peripheral blood cells in myasthenia gravis

Objective To study the expression kinetics of B7∶CD28/CTLA4 costimulatory pathway relevant molecules in patients with myasthenia gravis and the relationship between those with the pathogenicity of MG. Methods At 0?h, 6?h, 24?h, 48?h stimulated by PMA+ionomycin, two-color flow cytometry was used to count CD4+ and CD8+ T lymphocytes expressing of B7-1, B7-2, CD28, CTLA4 from 18 patients with MG and 16 healthy controls. Results (1) At 0?h, patients with MG had augmented percentages of B7-1+, B7-2+ cells, but no significant difference was found in the expressions of B7-1 and B7-2 molecules on CD4+ or CD8+ T lymphocytes between two groups after stimulating with PMA+ionomycin, the expressions of B7-1 and B7-2 molecules on CD4+ or CD8+ T lymphocytes were similar with thoses at 0?h; (2) At 0?h,patients with MG had augmented percentages of CD28+, CTLA4+ cells. The increased CD28+ cells were mainly of CD4+ T lymphocyte subset. The increased CTLA4+ cells were mainly composed of CD8+ T lymphocyte subset. After stimulating with PMA+ionomycin, the expression of CD28 increased significantly and maintained at high level through 6?h to 48?h ( P 0.01 comparing with control), while CTLA4 show maximal expression at 6?h and diminished levels observed at 24 and 48?h. Conclusion Patients with MG had a high expression of B7∶CD28/CTLA4 costimulatory pathway relevant molecules, and the duration is prolonged; examining of B7∶CD28/CTLA4 costimulatory molecules on peripheral blood cells may imply the immune state of MG patients. CD28-B7 costimulatory signal pathway is associated with the pathogeny of myasthenia gravis. [