mRNA expression of CD28/B7 molecules in the peripheral blood mononuclear cells of the patients with systemic lupus erythematosus and their significance

Objective:To investigate the roles of CD28/B7 molecules expression in the pathogensis of systemic lupus erythematosus and their significance.Methods:Applying reverse transcription polymerase reactin(RT PCR)technique to semiquantitatively analyze CD28?B7 1 and B7 2 mRNA expression in the Peripheral Blood Mononuclear Cells(PBMC)from 35 active SLE patients and 30 cases of healthy subjects.Results:Compared with normal controls,the positive rate of CD28 expression in active SLE patients accounted for 22 86%,which was markedly lower than the normal controls(70 00%),the difference was statistically significant( P 0 001),the SLE patients with positive rate of B7 2 expression accounted for 82 86% of the SLE patients in active stage,the difference was statistically significant( P 0 01);the mean level of CD28 mRNA expession in active SLE group was decreased( P0 05 ),however,the mean level of B7 2 mRNA expression in active SLE group was markedly increased( P0 01 ),there only are two positive expression of B7 1 molecule in 35 active SLE patients.Conclusion:The abnormal expression of CD28 and B7 molecules may be associated with aberrations or alterations of lymphocyte and APC in SLE patients and suggest that the ligation of CD28 and B7 2 may be an important pathway in Th2 mediated response and may play a pathological role in the development of SLE.The higher level of B7 2 expression may be related to disease activity of SLE.The lower expression of CD28 mRNA may contribute to the increased apoptosis of CD28 + T cells or the selective migration of these cells to sites of autoimmune injury in SLE patients.