中文摘要：

目的探讨程序性细胞凋亡基因（ programmed cell death-1, PDCD1 ） 第5外显子单核苷酸多态性（SNP）与中国南方汉族人群系统性红斑狼疮（systemic lupus erythematosus, SLE）易感性的关系。方法采用病例对照研究设计，收集132例病例和160例对照，应用PCR-RFLP技术检测PD1．6G〉A和PD1．5C〉T两个位点的SNPs，运用SAS8．2软件包进行基因型、等位基因和单倍型等的关联性分析。结果对照组PD1．6G〉A位点突变基因型AA频率高于SLE患者（X^2=5．123，P=0．023），患者中的A等位基因频率低于对照组（X^2=8．036，P=0．005）；PD1．5C〉T位点中，CT基因型在对照组中的比例较低（X^2=15．380，P=0．000），病例组的T等位基因频率高于对照组（X^2=11．631，P=0．001）。同时，两位点等位基因间存在连锁不平衡（X^2=10．708，P=0．001），且病例组和对照组单倍型分布不同（X^2=18．821，P=0．000）；其中，病例组A—C单倍型频率低于对照组（X^2=15．812，P=0．000），A—T和GT单倍型频率高于对照组（X^2=4．119，P=0．042和X^2=6．621，P=0．010）。结论在中国南方汉族人群中，PDCD1基因PD1．6G〉A和PD1．5C〉T两个位点多态性与SLE具有相关性，PD1．6G〉A的G—A突变可能是SLE的保护因素（OR=0．57，95％CI：0．39—0．84），PDl．5C〉T的C—T突变可能是SLE的危险因素（0R=2．02，95％CI：1．35—3．02）。A—T和GT单倍型可能是SLE的易感单倍型（OR=1．58，95％CI：1．02—2．46和0R=3．02，95％CI：1．30—7．02），A—C单倍型可能是SLE的保护性单倍型（OR：0．51，95％CI：0．36—0．71）。

英文摘要：

Objective To approach the association of two single nucleotide polymorphisms （SNPs） within the exon-5 of programmed cell death-1 （PDCD1） gene and the development of systemic lupus erythematosus（SLE） in Southern Chinese Han people. Methods 132 cases and 160 normal controls were enrolled with the aim of case-control design, and SNPs of PD1.6G）A and PD1. 5C）T were genotyped by PCR-RFLP. Moreover, we calculated ORs and LD as well as the frequencies of haplotypes for the two loci. Results It was found that mutated AA genotype frequency of PD1.6G）A in controls was significantly higher than the one in cases （X^2 = 5. 123, P = 0. 023）, and the frequency with A alleles in patients was significantly decreased relative to the one in healthy controls （X^2 = 8. 036, P= 0. 005）. In PD1.5C〉T, CT frequency in controls was lower than the one in cases with statistically significance （X^2 = 15. 380, P = 0. 000）, and the carrier frequency of T allele in cases was significantly increased compared with controls （X^2 = 11. 631, P = 0. 001）. Moreover, there were linkage disequilibriums between alleles of PD1.6G〉A and PD1.5 C〉T （X^2 = 10. 708, P = 0. 001）. The haplotype distributions between cases and controls were significantly different in PDCDI（X^2 = 18. 821, P = 0. 000）, with relative higher proportion of A-T and G-T haplotypes （X^2 = 4. 119, P = 0. 042; X^2 = 6. 621, P = 0. 010） and less proportion of A-C haplotype （X^2= 15. 812, P = 0. 000） in SLE group. Conclusions The polymorphisms of PD1.6G〉A and PD1.5C）T were associated with SLE in Southern Chinese Han people. The mutation of G→A in PD1.6G〉A might be protective from SLE （OR= 57, 95% CI.. 0. 39-0. 84） , while the C→T mutation in PD1.5C〉T might be harmful （OR = 2.02, 95% CI： 1.35 - 3.02）. The haplotypes of A-T and G-T might be susceptible to SLE （OR= 1.50, 95% CI： 1.02-2.46 and 0R=3.02, 95% CI：1.30-7.02）, and the A-C haplotype might play a protective role in development of SLE （OR= 0.51, 95% C