MBL基因多态性及血清MBL浓度与狼疮性肾炎的关系

Research on correlation of gene polymorphism of mannan-binding lectin and its serum concentration in lupus nephritis patients

目的探讨狼疮性肾炎(LN)与甘露聚糖结合凝集素(MBL)基因第一外显子54位密码子和启动子序列多态性及血清MBL浓度的关系。方法用聚合酶链反应-限制性片段长度多态性(PCR-RFLP)分析技术和序列特异性引物PCR(SSP-PCR)技术分析对照组(n=40)和LN组(n=49)MBL第一外显子54位密码子及启动子区-550的H/L和-221的X/Y多态性。用ELISA法测定血清MBL浓度。结果LN组MBL第54位密码子GAC等位基因频率高于对照组(0.173vs0.112),但无显著性差异;启动子单倍型LX显著高于对照组(P(0.05);对照组GGC/GGC基因型和启动子HY/HY型的血清MBL浓度显著高于LN组(P<0.05～0.01)。LN组和对照组中血清MBL浓度低于1000μg/L者分别为40.8%和17.5%,两组相比有显著性差异(P(0.05)。结论LN患者血清MBL浓度显著降低与MBL基因启动子LX型增加有关。

Objective To investigate the relationship between polymorphisms of both codon 54 of the first exon and promoter in mannan-binding lectin （MBL） gene variants and its serum concentration in patients with lupus nephritis （LN）. Methods The polymorphisms of MBL gene, at codon 54 of the first exon and -550 （H/L variants） and -220 （X/Y variants） of promoter region, were analyzed by polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） and sequence specific primers PCR （SSP-PCR） in LN patients group （ n = 49 ） and control group （ n = 40）. The serum concentrations of MBL were also determined by sandwich enzyme linked immunosorbent assay （ELISA）. Results The frequencies of GAC allele did not show difference between LN group （0. 173 ） and control group （0.112）. The patients with LN had significantly higher frequency of haplotype LX of promoter compared with controls （P 〈 0.05 ）. The serum concentrations of genotypes GGC/GGC and promoter HY/HY in control group were higher than those in LN group （ t = 2.07 - 3.93, P 〈 0.05 - 0.01 ）. The percentages of MBL concentration with lower than 1000 μg/L in serum were significantly different between LN patients （40.82%） and healthy subjects （ 17.5% ） （P 〈0.05）. Conclusion The lower serum levels of MBL in patients with LN may associated with increased promoter LX variant.