IgA肾病人腭扁桃体摘除前后外周血BAFF及IgA1低糖基化研究

发布时间：2018-05-03 22:26

  本文选题：IgA肾病 + 腭扁桃体　； 参考：《中南大学》2014年博士论文

【摘要】：研究背景：IgA肾病以IgAl/低糖基化IgAl沉积于肾小球系膜区及毛细血管袢为病理特征,以血尿、蛋白尿、高血压及肾功能损害为主要临床表现,是世界范围内最常见的原发性肾小球疾病。大约20-40%的患者在诊断为IgA肾病的20年内进展至终末期肾功能衰竭,是导致终末期尿毒症的最常见原因。 IgA肾病患者在黏膜组织,特别是上呼吸道和肠道黏膜感染后常出现阵发性肉眼血尿。既往也有研究IgA肾病患者在腭扁桃体摘除后出现一过性的尿检恶化,同时检测到血中IgAl一过性升高。即可以通过手术对腭扁桃体的牵拉、挤压等刺激,进行的腭扁桃体“激惹”试验。 B淋巴细胞刺激因子(B-cell-activation factor,BAFF),是肿瘤坏死因子(tumor necrosis factor,TNF)配体超家族的重要成员。BAFF通过对正常B细胞的成熟、增殖和分化的影响,对维持B淋巴细胞在体内的发展和体内的平衡起着重要的作用。但其临床应用还需要进一步的研究。 IgA具有IgAl和IgA2两种亚型,近年的研究证实低糖基化IgAl是IgA肾病的关键致病因子。IgAl与IgA2的主要区别点在于IgAl存在铰链区。在IgAl铰链区,β1,3半乳糖转移酶(C1GALT1)在其特异性分子伴侣(COSMC)的辅助下,通过UDP-半乳糖载体将半乳糖转移至IgAl的p1,3位乙酰半乳糖胺残基上,完成IgAl的糖基化修饰,而ST6GalNAcⅡ则将唾液酸转至IgAl的α2,6位乙酰半乳糖胺残基上,阻止了IgAl糖基化的修饰。IgA肾病外周血B淋巴细胞C1GALT1及COSMC活性明显下降,并且与IgAl病理损伤严重程度呈正相关,但是其活性下降的具体机制尚未阐明。既往研究发现,外周血B淋巴细胞在无刺激时ST6GalNAcⅡmRNA的表达与正常对照组相比降低,另有研究发现IgAl分泌细胞在IL-4、IL-6的刺激下ST6GalNAcⅡmRNA显著升高。 本课题中我们通过对IgA肾病患者以及对照组腭扁桃体摘除前后的研究,以腭扁桃体摘除术作为腭扁桃体“激惹”试验,观察腭扁桃体摘除前后外周血中的改变,分析其与外周血中B细胞活化、IgAl及其糖基化之间的关系,为IgA肾病的防治提供新的理论依据和治疗靶点。 第一章IgA肾病患者腭扁桃体摘除前后外周血BAFF及IgAl比较 目的：检测腭扁桃体摘除前后,外周血单个核细胞(PBMC)中BAFF以及血浆中IgAl表达,分析腭扁桃体与B细胞活化及IgAl之间的关系。 方法：收集经临床和肾脏病理确诊为IgA肾病患者在腭扁桃体摘除术术前(24-48h)术后(36-60h)的外周血16例做为IgA肾病组(IgAN组),行腭扁桃体摘除术的非IgA肾病患者术前术后外周血作为非IgA肾病组(non-IgAN组),以及正常对照组(healthy control组)16例。采用实时定量PCR(qRT-PCR)检测BAFF在PBMC中mRNA的表达ELISA检测血浆中IgAl含量。 结果： 1.qRT-PCR结果提示IgA肾病患者术前BAFF mRNA表达水平高于正常对照组(P0.01),IgA肾病患者术后BAFF表达较IgA肾病患者术前升高(P0.01),并高于非IgA肾病患者术后(P0.05)； 2.IgA肾病患者术前外周血血浆中IgAl的含量高于正常对照组(P0.05),IgA肾病患者术后血浆中IgAl的含量较术前升高(P0.01),并高于非IgA肾病患者术后(P0.05)； 3.相关性分析提示PBMC中BAFF mRNA表达与外周血IgAl含量呈正相关(r=0.604,P0.01)。 结论：本章实验通过模拟腭扁桃体感染,观察到IgA肾病患者PBMC中BAFF基因表达增加,外周血血浆中IgAl含量升高与BAFF的关系密切,BAFF及其基因表达变化也有望成为一项评估患者IgA肾病病程变化的无创性检测指标。 第二章ST6GaINAcⅡ、C1GALT1及COSMC在外周血单个核细胞表达及与IgAl低糖基化相关性分析 目的：检测腭扁桃体摘除前后,PBMC中ST6GalNAcⅡ, C1GALT1及COSMC表达以及外周血血浆中IgAl的低糖基化水平,分析腭扁桃体对低糖基化IgAl影响及IgAl低糖基化的调控机制。 方法：采用免疫组化方法检测IgA肾病患者与非IgA肾病患者腭扁桃体中ST6GalNAcⅡ的表达；采用qRT-PCR检测正常对照组、非IgA肾病组及IgA肾病组PBMC ST6GalNAcⅡ、C1GALT1及COSMCmRNA的表达；VVL-ELISA检测外周血血浆中IgAl低糖基化水平。 结果： 1.免疫组化结果显示ST6GalNAcⅡ在IgA肾病患者腭扁桃体中表达量高于非IgA肾病患者； 2.qRT-PCR结果提示IgA肾病患者术前ST6GalNAcⅡ mRNA表达水平高于正常对照组(P0.01),IgA肾病患者术后ST6GalNAcⅡ mRNA水平均较IgA肾病患者术前升高(P0.01),并高于非IgA肾病患者术后(P0.05)。IgA肾病患者术后36-48小时间,ST6GalNAcⅡ mRNA表达水平为术前的1.95倍(P0.01)；术后48-60小时间,ST6GalNAcⅡ mRNA表达水平为术前的1.38倍(P0.01)。 3.qRT-PCR结果提示IgA肾病患者术后C1GALT1、COSMCmRNA水平均较IgA肾病患者术前降低(P0.05)； 4.与正常对照组相比,IgA肾病组外周血血浆中的IgAl低糖基化程度明显增高； 5.相关性分析提示PBMC中ST6GalNAcII mRNA表达与IgAl低糖基化水平呈正相关。 结论：IgA肾病患者腭扁桃体摘除术后,PBMC中ST6GalNAcII基因表达增加,C1GALT1、 COSMC基因表达减少,外周血血浆中Gd-IgAl含量升高,结合既往的研究,我们认为PBMC中ST6GalNAcII活性的增高及C1GALT1/COSMC活性的降低,导致了对外周血中低糖基化IgAl分泌的增多。
[Abstract]:Background : IgA nephropathy is characterized by IgA1 / low glycosylated IgA1 deposited in glomerular mesangial area and capillary loop . It is the most common primary glomerular disease in the world . Approximately 20 - 40 % of patients progressed to end - stage renal failure during 20 years of diagnosis of IgA nephropathy , which is the most common cause of end - stage uremia .

IgA nephropathy patients often suffer from paroxysmal gross hematuria after mucosal tissue , especially in upper respiratory tract and intestinal mucosa .

B - cell - activation factor ( BAFF ) is an important member of tumor necrosis factor ( TNF ) ligand superfamily . BAFF plays an important role in the development of B - lymphocytes in vivo and in vivo .

IgA has two subtypes of IgA1 and IgA2 . In recent years , it has been proved that low glycosylated IgA1 is the key pathogenic factor of IgA nephropathy . The main difference between IgA1 and IgA2 is that IgA1 has a hinge region .

In this study , we studied the relationship between the activation of B - cell , IgA1 and its glycosylation in peripheral blood of patients with IgA nephropathy and the control group , and analyzed the relationship between the activation of B - cell , IgA1 and its glycosylation in peripheral blood , and provided a new theoretical basis and therapeutic target for the prevention and treatment of IgA nephropathy .

The comparison of BAFF and IgA1 in peripheral blood of patients with IgA nephropathy

Objective : To detect the expression of IgA1 in peripheral blood mononuclear cells ( PBMC ) before and after the removal of palatine tonsilla , and to analyze the relationship between the activation of the palate and the activation of B cells and IgA1 .

Methods : 16 cases of IgA nephropathy patients ( 36 - 60h ) were collected from peripheral blood of IgA nephropathy group ( 36 - 60h ) before operation ( 36 - 60h ) . 16 cases of non - IgA nephropathy group ( non - IgAN group ) and 16 normal control group ( healthy control group ) were detected by real - time quantitative PCR ( qRT - PCR ) .

Results :

1.qRT - PCR results suggest that the expression level of BAFF mRNA in IgA nephropathy patients is higher than that in normal control group ( P0.01 ) , and the expression of BAFF in IgA nephropathy patients is higher than that in normal control group ( P0.01 ) , which is higher than that in non - IgA nephropathy patients ( P0.05 ) .


2 . The content of IgA1 in plasma of IgA nephropathy patients was higher than that in normal control group ( P0.05 ) , and the content of IgA1 in plasma of IgA nephropathy patients was higher than that in normal control group ( P0.01 ) , and higher than that in non - IgA nephropathy patients ( P0.05 ) .


3 . Correlation analysis suggested that the expression of BAFF mRNA in PBMC was positively correlated with the content of IgA1 in peripheral blood ( r = 0.6604 , P0.01 ) .

Conclusion : In this chapter , the expression of BAFF gene in PBMC of patients with IgA nephropathy is increased and the expression of BAFF and its gene expression in peripheral blood plasma is closely related to BAFF . BAFF and its gene expression are expected to be a non - invasive detection index for assessing the course of IgA nephropathy in patients with IgA nephropathy .

The correlation between the expression of ST6GaINAc 鈪，

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