Department of Clinical Immunology, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry 605006, India.
Department of Pediatrics, Jawaharlal Institute of Postgraduate Medical Education and Research (JIPMER), Puducherry 605006, India.
Immunobiology. 2014 Jun;219(6):465-8. doi: 10.1016/j.imbio.2014.02.004. Epub 2014 Feb 25.
Complement system is an important effector component of the innate immune system. More than 30 plasma proteins undergo a cascade of enzymatic reactions to produce effector molecules to clear infectious microbes, immune complexes, post apoptotic cellular debris and thus participate in prevention of autoimmunity. Absolute deficiency of individual complement components and selective deficiency of classical pathway complement components are reported to be associated with severe infections and a high risk for lupus like syndromes. Genetic defects in gene encoding for complement components were reported to be associated with complement deficiency. This study was carried out to investigate whether C1q and C2 polymorphisms are risk factors for SLE in south Indian Tamils.
Three hundred SLE patients fulfilling ACR criteria for SLE and 460 age and sex similar ethnicity matched individuals were included as patients and healthy controls respectively. The genomic DNA obtained from both the groups was screened for two polymorphisms including a C/T transition in exon 2 of C1qA (rs121909581) by PCR-RFLP and a 28bp deletion in sixth exon of C2 gene by PCR.
C1q exon 2 C/T polymorphism analysis revealed that homozygous CC was the most common genotype in patients and controls. A single SLE patient was found to have heterozygous variant (CT). None of the patients or healthy controls were found to have 28bp deletion variant of C2 gene.
The C/T polymorphism in exon 2 of C1qA and a 28bp deletion in sixth exon of C2 gene were found to be rare in south Indian Tamil SLE patients. They do not appear to be susceptibility factors for SLE in Indian Tamils.
补体系统是先天免疫系统的重要效应成分。超过 30 种血浆蛋白通过级联酶促反应产生效应分子，以清除感染性微生物、免疫复合物、凋亡后细胞碎片，从而参与预防自身免疫。个体补体成分的绝对缺乏和经典途径补体成分的选择性缺乏与严重感染和狼疮样综合征的高风险相关。编码补体成分的基因缺陷被报道与补体缺乏有关。本研究旨在探讨 C1q 和 C2 多态性是否是南印度泰米尔人患 SLE 的危险因素。
300 名符合 ACR 诊断 SLE 标准的 SLE 患者和 460 名年龄和性别相匹配的同种族个体分别作为患者和健康对照组纳入研究。从两组中提取基因组 DNA，通过 PCR-RFLP 检测 C1qA 外显子 2 中的 C/T 转换（rs121909581）和 PCR 检测 C2 基因第六外显子中的 28bp 缺失两种多态性。
C1q 外显子 2 C/T 多态性分析显示，纯合 CC 是患者和对照组中最常见的基因型。一名单例 SLE 患者存在杂合变异（CT）。未发现患者或健康对照者存在 C2 基因 28bp 缺失变异。
南印度泰米尔 SLE 患者中 C1qA 外显子 2 的 C/T 多态性和 C2 基因第六外显子的 28bp 缺失较为罕见。它们似乎不是印度泰米尔人患 SLE 的易感因素。
