Expression Of Co-stimulatory Molecule OX40 On CD4~+T-cells From Patients With Myasthenia Gravis

Objective:To investigate the expression of co-stimulatory molecule OX40 on CD4~+?T-cells in peripheral blood from patients with myasthenia gravis(MG)and to explore the possible pathogenesis.Methods:42 patients with MG and 37 healthy people were recruited, The serum antibodies of acetylcholine receptor (AchR-Ab), tintin (Titin-Ab)and ryanodine receptor (RyR-Ab) were tested using enzyme-linked immunosorbent assay(ELISA), The percentage of OX40~+CD4~+T cells and Foxp3~+CD4~+CD25~+regulatory T cells (Tregs) in peripheral blood were detected using flow cytometry (FCM). The counts of OX40~+CD4~+T cells were compared among different groups, The effect of OX40~+CD4~+T cells on FoxP3 ~+CD4~+CD25~+Tregs was observed.Results:(1) Expression of OX40~+CD4~+T-cell in peripheral blood was significantly higher in MG than in controls(p<0.01), Expression of OX40~+CD4~+T-cells in generalized MG was higher than ocular MG (p<0.05), acute group was higher than remission group (p<0.05) ,antibody positive groups were higher than negative groups (p<0.05), MG with thymus hyperplasia and thymoma were higer than MG with thymus normal (p<0.05). (2) There was negative correlation between the expression of Foxp3~+CD4~+CD25~+Tregs and OX40~+CD4~+T cells in peripheral blood in MG (r =-0.843, p=0.01).Conclusion:(1) OX40 might contribute to the occurrence and development of MG. (2) There was negative correlation between Foxp3~+CD4~+CD25~+Tregs and OX40~+CD4~+T cells in peripheral blood in MG, suggesting that OX40 might supress expression of FoxP3 ~+ CD4 ~+CD25~+ Treg to participate in MG pathogenesis.