Abstract: Objective To investigate the role of CD40 and CD40 ligand (CD40L)in the pathogenesis of systemic lupus erythematosus (SLE)and its clinical significance. Methods Applying RT-PCR technique to semiquantitatively analyze CD40 and CD40L mRNA expression in PBMC from 34 SLE patients. Results Compared with normal controls,the positive CD40L expression accounted for 88.24% of active SLE patients(P<0.001); the mean level of CD40L mRNA expression in active SLE group was markedly increased as well (P<0.0001). However,there were no statistical differences in positive rate of CD40 and the average level of CD40 mRNA between the two groups(P >0.05,both). Conclusions The abnormal expression of CD40L might play an important role in the pathogenesis of SLE,and the level of CD40L might be used as one the indices for active SLE.

Key words: Lupus erythematosus,systemic, Antigens,CD40, Ligand,CD40