Abstract: Objective:To investigate the gene expression level of PXK MRNA in peripheral blood leucocytes of patients with systemic lupus erythematosis(SLE),and the relationship between the MRNA expression of PXK and the clinical manifestation of SLE.Methods:Sixty SLE patients and 30 controls were enrolled; reverse transcription-polymerase chain reaction technique was used to determine the PXK MRNA expression in the peripheral white blood cells in them.Results:The PXK MRNA expression in the peripheral blood leucocytes of the SLE patients was statistically higher than that of the normal control(P 0.01).The expression level of PXK MRNA in the SLE patients was positively correlated with the production of the anti-SmithD1 antibody(P 0.05); the expression of PXK MRNA in the SLE patients was positively correlated with C3 and C4,respectively(P 0.05).Conclusions:The results indicate that PXK gene may play a role in the pathogenesis of SLE,and might be the susceptibility genes of SLE.