Abstract: Objective:To analyze the relationship between the mRNA level of SmD1 antigen and the level of anti-SmD1 antibod in patients with systemic lupus erythematosws (SLE).Methods:The blood samples from 30 SLE patients with high level of anti-SmD1 antibody,30 cases with normal level of anti-SmD1 antibody and 30 normal controls were collected.The mRNA level of SmD1 antigen was detected by real-time PCR in all the cases.SPSS11.5 was used for statistical analysis.Results:In the SLE patients with high level of anti-SmD1 antibody,patients with normal level of anti-SmD1 antibody and the normal controls,-△△CT of real-time PCR was-0.60±2.99,-0.04±1.92 and-0.00±2.80,respectively.The difference was not significant (P>0.05).Conclusions:The gene expression level of SmD1 has no significant different among the three groups.The immune abnormity in the cases with SLE is almost involved in the whole immune system.It is impossible to explain the disorder of immune system by the abnormity of mRNA level of SmD1 antigen.