Abstract: Objective Through studing the genotype and quantitatively analysing expression of type Ⅰ complement receptor(CR1) on erythrocytes from the patients with systemic lupus erythematosus(SLE). To investigate the relationship between CR1 and SLE. Methods Polymerase chain reaction(PCR) and Hind Ⅲ restriction enzyme digestion were used to analyse the genotype of CR1, and the quantitative expression of CR1 was demonstrated by FACscan flow cytometry. Results Compared with normal controls, high expression genotype of CR1 was significantly decreased, but low expression genotype was significantly increased in SLE patients. The number of CR1 on erythrocytes in SLE patients was significantly lower than that in normal controls. There was a negative relationship between the expression of CR1 and disease activity index of SLE (SLEDAI). Conclusion The expression of CR1 on erythrocytes might be related to the development of SLE, and it is helpful to detect the CR1 on erythrocytes for the determination of SLE patient's condition.

Key words: Lupus erythematosus, systemic, Receptors, complement, Erythrocytes