Expression And Transcription Of FcγRⅡa Gene In SLE Patients

Background: FcγRIIa is a low affinity receptor that has two co-dominantly expressed alleles, R131 and H131, which differ in their ability to bind immunoglobulin G (IgG) subclasses. Cells expressing H131 bind more efficiently complexed IgG2 and IgG3 than those expressing the R131 variant. The FcγRIIa polymorphism hasn't been shown to be associated with systemic lupus erythematosus and FcγRIIa-R/R131 over-expression maybe lead to the hige positive rate of ANCA and CIC in SLE patients .Objective:here we evaluated the relevance of FcγRIIa gene polymorphism in the development of systemic lupus erythematosus at transcriptional level by comparing the genotype and allelic distribution of this receptor and measure ANCA and CIC in systemic lupus erythematosus to ethnically matched healthy controls in Yunnan.Methods: 69 systemic lupus erythematosus (SLE) patients and 48 healthy volunteers were recruited. FcγRIIa genotyping was performed by nest PCR with allele-specific primers to distinguish between the two allelic forms (H131 and R131) .The transcription information of FcγRIIa gene was accomplished by RT-PCR.ANCA and CIC were implemented by ELISA .Results : Comparison of FcTRIIa genotypes distribution in SLE patients and in controls showed a significant increase in FcγRIIa-R131 homozygosity (P< 0．02) The genotype distribution in sle (45% with Fc7RIIa-R/R131, 30% with H/R131 and 25% with H/H131) was distinct from that observed in controls (21% with FcγRIIa-R/R131, 52% with H/R131 and 27% with H/H131) . In addition mRNA of FcγRIIa-R/R131 express in SLE patients and in controls showed a significant increase in FcγRIIa-R131 homozygosity (P<0．05) Moreover,the positive rate of ANCA(67．9%) and CIC (86．1%) with FcγRIIa-R/R131 was distinct from that observed in FcγRIIa-H/R131 and FcγRIIa-H/H131 (ANCA:21．4% with H/R131,10．7% with H/H131 ;CIC:86．1%; 11with H/R131; 2 % with H/H131)Conclusions:The skewed distribution of FcγRIIa genotypes with the predominance of homozygous R/R131 genotype observed in SLE patients and in controls emphasizes its importance as a heritable risk factor for Yunnan SLE patients. FcγRIIa-R/R131 over-expression maybe lead to the hige positive rate of ANCA and CIC in SLE patients .