Objective To explore the association of CD40 gene single nucleotide polymorphisms (SNPs) and haplotypes with the susceptibility to systemic lupus erythematosus (SLE),as well as the association of serum levels and genotypes of CD40 with the occurrence of SLE.Methods A multiplex PCR single-base extension assay (PCR-SBE) and DNA sequencing were performed to analyze 4 SNPs of the CD40 gene,including rs1883832 C/T,rs13040307 C/T,rs752118 C/T and rs3765459 G/A,in 205 patients with SLE (SLE group) and 220 healthy human controls (control group).Enzyme-linked immunosorbent assay (ELISA) was conducted to measure serum levels of CD40 in these subjects.Results Compared with the control group,the SLE group showed significantly increased serum levels of CD40 (P ＜ 0.05).There were significant differences in genotype and allele frequencies of the SNP rs1883832 C/T in the CD40 gene between the SLE group and control group (all P＜ 0.01).Relative risk analysis showed that the risk of developing SLE in rs1883832 T allele carriers was 1.517 times that in rs1883832 C allele carriers (OR =1.517,95％ CI:1.157-1.990,P=0.003).Moreover,serum levels of CD40 were significantly higher in rs1883832 T allele carriers than in rs1883832 C allele carriers (P ＜ 0.01).The risk of developing SLE was significantly increased in TCCA haplotype carriers compared with the healthy controls (OR =2.322,95％ CI:1.181-4.564,P=0.012).Conclusion The CD40 gene rs1883832 C/T polymorphism and its TCCA haplotype were both associated with the occurrence of SLE,and the rs1883832 T allele may be a gene predisposing to SLE.

OBJECTIVETo investigate the association of SNP of CD40 gene and its serum levels with ischemic stroke (IS).

METHODSA total of 202 IS patients from a hospital of Baise city were enrolled in case group from May 2013 to November 2014. At the same time, 109 healthy people who had physical check-ups in the outpatient department at the same hospital were enrolled in the control group. All participants were from Guangxi Zhuang Autonomous Region and unrelated to each other. 3 ml venous blood were collected on the premise of informed consent. The single nucleotide polymorphisms of CD40 gene rs1883832 C/T, rs13040307 C/T, rs752118 C/T and rs3765459 G/A were analyzed using a Snapshot SNP genotyping assays, and the serum levels of CD40 were tested by ELISA. t-test was used to compare the serum levels of CD40 between the case and control group, and the genotypes at different locuses in case group; χ(2) test was used to compare the distribution differences of the CD40 gene locuses in different genotypes and allele between the case group and the control group; alleles was established as independent variables, the occurrence of the IS as dependent variable, and expressed relative risk with OR (95%CI) value.

RESULTSIn the case group, the frequency of CC, CT and TT genotypes in CD40 gene rs1883832 C/T were 21.78% (44/202), 49.51% (100/202) and 28.71% (58/202), respectively, and 33.17% (66/199), 48.74% (97/199), 18.09% (36/199) in the control group, respectively, the differences between the two groups was significant (χ(2)=9.57, P=0.008). The CD40 serum levels were (62.7 ± 24.5) pg/ml in the case group, which was higher than that in the control group (45.3 ± 17.2) pg/ml (t=8.97, P<0.001). The serum levels of TT and CT genotypes in CD40 gene were (65.9 ± 26.3) and (64.3 ± 25.9) pg/ml, respectively, and the differences were significant when comparing with CC genotype (t equaled 5.34 and 5.03, respectively, P<0.001). The risk of developing IS was 1.56 times higher in 1883832 T allele carriers than that in rs1883832 C allele carriers (OR=1.56, 95% CI: 1.18-2.06); Combined genotype analysis displayed that CD40 gene rs1883832 C/T, rs13040307 C/T, rs752118 C/T and rs3765459 G/A polymorphisms showed strong linkage disequilibrium, the case group TCCA haplotype was tested to be associated with a significantly increased risk of IS as compared with that in the control group(OR=2.49; 95%CI: 1.13-5.48).

CONCLUSIONCD40 gene rs1883832 C/T polymorphism and its TCCA haplotype were possibly associated with ischemic stroke, and the susceptibility gene for ischemic stroke may be rs1883832 T allele.

Alleles ; CD40 Antigens ; blood ; genetics ; Case-Control Studies ; Cell Differentiation ; China ; Gene Frequency ; Genetic Predisposition to Disease ; Genotype ; Haplotypes ; Humans ; Polymorphism, Single Nucleotide ; Stroke ; blood ; genetics