导语：系统性红斑狼疮（SLE）是一种常见的自身免疫性疾病，具有复杂的遗传背景。白细胞介素21（IL-21）属于新发现的I型细胞因子家族，对免疫系统有多种功能效应，包括B细胞活化，浆细胞分化和免疫球蛋白产生。以往的研究已明确IL -21与多种自身免疫性疾病和炎性疾病相关，如类风湿关节炎，多发性硬化和系统性红斑狼疮。DNA序列中IL-21基因的变异可能导致IL-21产生和/或活性变化，进而影响SLE个体的易感性。
标签：IL-21基因 SLE
系统性红斑狼疮（SLE）是一种常见的自身免疫性疾病，具有复杂的遗传背景。白细胞介素21（IL-21）属于新发现的I型细胞因子家族，对免疫系统有多种功能效应，包括B细胞活化，浆细胞分化和免疫球蛋白产生。以往的研究已明确IL -21与多种自身免疫性疾病和炎性疾病相关，如类风湿关节炎，多发性硬化和系统性红斑狼疮。DNA序列中IL-21基因的变异可能导致IL-21产生和/或活性变化，进而影响SLE个体的易感性。
为了检验这一假设，来自右江民族医学院的Yan Lan等人进行了一项研究，研究结果2014年1月在线发表在Gene杂志上。研究主要分析了IL-21基因多态性及其血清水平与中国人群SLE发病风险的关联性研究。
研究纳入了175例SLE患者和190例年龄和性别匹配的对照组的IL-21基因的rs907715 C/T，rs2221903 T/C和rs2055979C/A 位点上的3个单核苷酸多态性，采用快照SNP基因分型检测及DNA测序方法。ELISA方法检测血清可溶性IL- 21（SIL -21）水平。SLE患者和对照组的IL-21基因在rs2055979 C/A位点的基因型和等位基因频率有显着差异（P< 0.05）。与对照组相比相比，SLE患者的sIL- 21水平升高（P <0.01）。此外，与野生型纯合子基因型SLE患者相比，携带IL-21rs2055979变异体基因型患者的IL-21水平明显增加。在中国人群中，IL-21的rs2055979 C/A位点的多态性及sIL-21水平与系统性红斑狼疮相关。
因此，作者认为，IL-21基因可能在SLE的发展起到一定的作用。
原文阅读：The association of interleukin-21 polymorphisms with interleukin-21 serum levels and risk of systemic lupus erythematosus
Abstract
Systemic lupus erythematosus （SLE） is one of the common autoimmune diseases, with complex genetic components. Interleukin-21 （IL-21） is the most recently discovered member of the type-I cytokine family, which has a variety of effects on the immune system, including B cell activation, plasma cell differentiation, and immunoglobulin production. Previous studies have identified that IL-21 was associated with different autoimmune and inflammatory diseases, such as rheumatoid arthritis, multiple sclerosis and SLE. Variations in the DNA sequence in the IL-21 gene may lead to altered IL-21 production and/or activity, and thus this can modulate an individual's susceptibility to SLE. To test this hypothesis, we investigated the association of the IL-21 polymorphisms and its serum levels with the risk of SLE in a Chinese population. We analyzed three single nucleotide polymorphisms of IL-21 gene rs907715 C/T, rs2221903 T/C and rs2055979 C/A in 175 patients with SLE and 190 age- and sex-matched controls, using Snapshot SNP genotyping assays and DNA sequencing method. Soluble IL-21 （sIL-21） levels were measured by ELISA. There were significant differences in the genotype and allele frequencies of IL-21 gene rs2055979 C/A polymorphism between the group of patients with SLE and the control group （P < 0.05）。 sIL-21 levels were increased in patients with SLE compared with controls （P < 0.01）。 Moreover, genotypes carrying the IL-21 rs2055979 A variant allele were associated with increased IL-21 levels compared to the homozygous wild-type genotype in patients with SLE. The rs2055979 C/A polymorphism of IL-21 and its sIL-21 levels were associated with SLE in the Chinese population. Our data suggests that IL-21 gene may play a role in the development of SLE.
编辑：范伟伟
