Abstract: Objective To study the relationship between CD80/CD86 expression in B cells and immune disorders in patients with immune thrombocytopenia（ITP）. Methods 90 patients with ITP were enrolled in the study,the flow cytometry was used to detect the expression CD80⁺/CD86⁺in CD19⁺B cells,the IgG/IgM level in peripheral blood. All patients were treated with recombinant human thrombopoietin （rhTPO） and prednisone,the complete remission rate was recorded by followed up,Logistic analysis was used to test the risk factors of the prognosis of ITP the partial correlation analysis was used to test relationship between CD19⁺CD80⁺,CD19⁺CD86⁺ and IgG,IgM expression. Results The patients were followed up for 3-11 months with an average follow-up time of （7.95±2.74） months,the complete remission rate of ITP was 46.67%. The multivariate analysis showed that CD19⁺CD80⁺,CD19⁺CD86⁺,IgG and IgM level were the high risk factors of prognosis （P<0.05）.The CD19⁺CD80⁺ and IgG,IgM had linear distribution,the partial correlation analysis showed significant positive correlation（r=0.229,0.592;P=0.031,P<0.001）.The CD19⁺CD86⁺and IgG,IgM had linear distribution,the partial correlation analysis showed significant positive correlation（r=0.415,0.292,P<0.001,0.005）. Conclusion The CD80 and CD86 are closely related to immune disturbances,and they are the high risk factors for the prognosis of patients with ITP,the over expression of CD80 and CD86 in B cells may be the important mechanism for over activation of CD19⁺B cells and mediated immune dysfunction.

Key words: ITP, CD80, CD86, Immune disorder