Expression and significance of CD28/CTLA-4:B7 in peripheral blood lymphocytes of patients with idiopathic thrombocytopenic purpura

Objective:To investigate the expression and significance of co-stimulatory molecules CD28,cytotoxic T-lymphocyte-associated antigen-4 (CTLA-4,CD152),B7-1 (CD80) and B7-2 (CD86) in lymphocytes from patients with idiopathic thrombocytopenic purpura (ITP).Method:Blood samples were collected from 41 ITP patients and 40 healthy controls. The percentages of CD3+CD28+,CD3+CD152+,CD80+CD19+ and CD86+CD19+ cells on lymphocytes were determined with flow cytometry and monoclonal antibodies technology. Platelet-associated immunoglobulins (PAIg) in ITP were assayed with flow cytomerty.Result:The percentages of CD3+CD28+ and CD3+CD152+ cells were not different among three groups. We observed higher proportions of CD80+CD19+ cells in acute ITP patients than in controls and chronic ITP patients. The percentage of CD86+CD19+ cells in chronic ITP patients was higher than in controls and acute ITP patients. The levels of PAIg's,PAIgG and PAIgM in acute ITP patients were higher than in controls and chronic ITP patients. The level of PAIgG in chronic ITP patients were higher than in controls. The expression of CD80 and CD86 had positive correlation with the level of PAIgG.Conclusion:The excessive expression of CD86 and CD80 in B cells may be related to the pathogenesis of ITP.