上海人群中TAP、LMP和HLA-DM基因多态性研究

调查上海人群中抗原处理相关基因TAP、LMP和HLA-DM的分布情况,并探索这些基因与自身免疫病类风湿关节炎(RA)、IgA肾炎(IgAN)和多发性硬化症(MS)的可能关联。应用PCR-SSO或PCR-RFLP技术对80名无血缘关系的上海地区正常人及156名RA患者、60名IgAN患者和21名MS患者作了TAP1、TAP2、LMP2、HLA-DMA和HLA-DMB基因分型。并作了两位点连锁不平衡分析。在该群体中,(1)共观察到4个TAP1、6个TAP2、2个LMP2、4个HLA-DMA和4个HLA-DMB等位基因;(2)在TAP1B-TAP2A、TAP1B-LMP2H和TAP2D-DMA*0101存在连锁不平衡(Pc<0.05);(3)本人群中IgAN和MS的遗传易感性与抗原处理相关基因无关,而RA患者中DMB*0101基因频率降低(P<0.01),TAP1C和DMB*0104等位基因频率显著升高(P<0.01)。比较分析表明,上海人群中抗原处理相关基因多态性与国外其他人种中的报道相似,本人群中IgAN和MS与抗原处理相关基因不关联,而TAP1C和DMB*0104等位基因可能是RA的遗传易感基因。     

上海人群抗原处理相关基因的分布及其与原发性IgA肾炎关联研究

采用PCR SSO和PCR RFLP技术对 6 0例经临床及肾穿刺证实的IgA肾炎 (IgAN )患者和 80例正常人的TAP、LMP2和DM等位基因频率进行了检测。结果显示在患者和正常人中各等位基因频率均无显著性差异 ,表明IgAN与抗原处理相关基因无关联。同时分析了经典Ⅱ类基因 (DR/DQ/DP )和抗原处理相关基因 (TAP/LMP2 /DM )之间可能存在的连锁不平衡 ,获得了扩展的HLAⅡ类单倍型 ,为HLAⅡ类基因与某些自身免疫病的关联性研究提供了有价值的数据     

抗原处理相关转动蛋白（TAP）的研究进展

抗原处理相关转运蛋白（TAP）负责内源性抗原从胞浆到内质网的转运,在MHCⅠ类分子的抗原呈递过程中发挥重要的作用。TAP属于ABC超家族成员,其两个亚基共同参与组成肽结合部位,由于具有一定的多态性,对底物具有选择性转运现象,TAP同时还参与了MHCⅠ类分子的组装。体内外多种因素可以调节TAP的表达和活性,从而影响病毒感染过程和肿瘤的发生。     

Heymann肾炎致病原受体相关蛋白羧基端多肽表达…

本研究中，用ＰＣＲ方法扩增了受体相关蛋白基因第６３３－９５７碱基ｃＤＮＡ片段。将编码成熟分子量为４４×１０＾３受体相关蛋白和羧基端１０８氨基酸多肽的ｃＤＮＡ克隆到表达载体ｐＧＥＸ－４Ｔ－１内，限制性图谱分析测定了插入子的方向并用ＤＮＡ序列分析加以证实。     

广东汉族人群LMP和TAP基因多态性及与变应性鼻炎的相关性

目的对广东地区汉族变应性鼻炎患者作抗原处理相关肽(TAP)和低分子量多肽(LMP)分型,探讨这些基因与广东人群中变应性鼻炎遗传易感性的可能关系。方法采用PCR扩增阻碍突变系统(PCR-ARMS)法和PCR-RFLP法对62名无亲缘关系的变应性鼻炎病人和95名无血缘关系的广东籍健康汉族人作TAP、LMP分型。结果TAPl-333、637位等位基因基因型在广东汉族变应性鼻炎组及正常对照组中均以I和D为主,TAP2-379、565、665等位基因基因型分别为V-A-T。TAP1和TAP2各等位基因基因型频率在变应性鼻炎组和正常人组间差异无显著性(P>0.05)。变应性鼻炎患者LMP7A/A频率占8.70%,低于正常对照组的21.35%,有显著差异(P<0.05),其余各型与正常对照组无明显差异(P>0.05)。变应性鼻炎病人中LMP7等位基因A的频率占36.23%,B的频率占63.77%,与正常对照组的A为47.09%、B为52.91%有显著差异(P<0.05)。结论提示LMP7等位基因A与AR的发病呈负关联,B与AR的发病呈正关联。变应性鼻炎与TAP基因可能无相关性.     

上海地区正常人群中TAP多态性调查

报告一组无血缘关系的上海地区正常人中抗原处理相关转运蛋白（ＴＡＰ）的分布。在８８名正常人中共观察到３种ＴＡＰ１和４种ＴＡＰ２等位基因，其中包括罕见的ＴＡＰ２Ｈ等位基因。并将上海人群中ＴＡＰ的分布与日本人和白种人中ＴＡＰ的分布作了比较。     

维吾尔族人群抗原处理相关转运体(TAP)基因多态性及与类风湿关节炎的相关性

目的：探讨新疆维吾尔族人群抗原处理相关转运体（ＴＡＰ）基因多态性及与类风湿关节炎（ＲＡ）的相关性。方法：采用ＰＣＲＡＲＭＳ,ＲＦＬＰ,ＳＳＯＰ检测ＲＡ患者３９例及健康献血者４１例ＴＡＰ１３３３和６３７位,ＴＡＰ２３７９、５６５、６５１、６６５、６８７等位氨基酸等位基因多态性。结果：健康维吾尔族人群ＴＡＰ１３３３位和６３７位等位基因基因型分别以Ｉ和Ｄ为主,表现型主要为Ｉ和ＤＤ,有１Ａ～１Ｄ４个亚型,以１Ａ和１Ｂ为主;ＴＡＰ２３７９、５６５、６５１、６６５、６８７等位基因型分别以ＶＡＲＴＱ为主,表现型以ＶＶＡＴＲＲＴＴＱＱ为主,有２Ａ～２Ｈ共８个亚型,以２Ａ和２Ｂ为主。ＲＡ患者ＴＡＰ２３７９Ｉ,５６５Ｔ和６８７Ｓ频率,５６５ＴＴ,６８７ＳＳ及ＴＡＰ１Ｂ频率显著升高,并且ＴＡＰ１Ｂ可使ＤＲ４阳性者患ＲＡ的相对危险性增加５．３３倍。结论：维吾尔族健康人群及ＲＡ患者ＴＡＰ基因多态性有不同于其他民族人群的基本特点。ＴＡＰ１Ｂ可使ＤＲ４阳性者患ＲＡ的相对危险性增加,并可能是维吾尔患者ＲＡ的易感基因。     

HLA-DQB1基因多态性与新疆维吾尔族人群结核病易感性的相关性研究

目的:探讨人类白细胞抗原(HLA)-DQB1基因多态性与新疆维吾尔族人群结核病易感性的关联.方法:采用病例一对照的研究方法,应用聚合酶链反应一序列特异性引物(PCR-SSP)技术对226例新疆维吾尔族肺结核病患者(肺结核病例组)和231例新疆维吾尔族健康对照者(健康对照组)进行HLA-DQB1基因分型,比较其等位基因频率(GF),并计算其比值比(OR).结果:肺结核病例组中HLA-DQB1*0201基因频率显著高于健康对照组,两组的GF分别为40.13%、19.15%,差异有统计学意义(P<0.05);肺结核病例组中HLA-DQB1*0301/4基因频率显著低于健康对照组,两组的GF分别为6.16%、10.27%,但P值经过校正后无显著性差异(P0.05).结论:HLA-DQB1*0201等位基因与新疆维吾尔族人群结核病强相关,DQB1*0201可能是其易感基因.     

Heymann肾炎致病原受体相关蛋白羧基端多肽表达的研究

本研究中，用ＰＣＲ方法扩增了受体相关蛋白基因第６３３～９５７碱基ｃＤＮＡ片段。将编码成熟分子量为４４×１０３受体相关蛋白和羧基端１０８氨基酸多肽的ｃＤＮＡ克隆到表达载体ｐＧＥＸ－４Ｔ－１内，限制性图谱分析测定了插入子的方向并用ＤＮＡ序列分析加以证实。带有质粒ｐＧＥＸ－Ｒ９３（包含完全ＲＡＰｃＤＮＡ９５７碱基）的重组菌过度表达了分子量为６５×１０３融合蛋白，其含量占总蛋白的３９．４％。带有质粒ｐＧＥＸ－Ｒ３５（包含ＲＡＰｃＤＮＡ３２４碱基）表达了４０×１０３的融合蛋白，蛋白含量３２．２％。通过谷胱甘肽亲和层析柱，从细菌溶解物中纯化了融合蛋白，每升培养物能纯化到１０～２０ｍｇ的蛋白，Ｗｅｓｔｅｒｎｂｌｏｔ分析证明抗Ｒ９３和抗Ｒ３５两种抗血清特异性结合到大鼠肾皮质微绒毛提取物中的４０×１０３的带。间接免疫荧光显示抗Ｒ９３和抗Ｒ３５两种抗体标记肾近曲小管刷状缘抗原。文中对表达的受体相关蛋白的意义和其抗原性进行了讨论。     

IgA肾病与系膜增生性肾炎临床特征的比较

目的 比较IgA肾病与系膜增生性肾炎的临床特征。方法 选取2018年1月~2019年3月在我院肾内科就诊的32例IgA肾病患者设为观察1组,将32例系膜增生性肾小球肾炎患者设为观察2组,比较两组患者的年龄、临床表现（水肿、血尿、血压升高）和辅助检查指标（胆固醇、尿蛋白、IgG、IgA）。结果 观察1组患者年龄＜25岁的比例高于观察2组（56.25% vs 37.50%）,观察2组患者年龄为45~65岁的比例高于观察1组（34.37% vs 12.50%）,差异均有统计学意义（P＜0.05）。观察1组患者水肿症状的比例低于观察2组（18.75% vs 50.00%）,血尿、血压升高的比例高于观察2组（43.75% vs 21.87%,37.50% vs 28.13%）,差异均有统计学意义（P＜0.05）。观察1组尿蛋白、胆固醇水平低于观察2组,IgG、IgA水平高于观察2组,差异具有统计学意义（P＜0.05）。结论 与系膜增生性肾小球肾炎比较,IgA肾病发病年龄更小,主要表现为血尿和血压升高,系膜增生性肾小球肾炎中年发病较多,主要表现为水肿、高胆固醇,研究结果对临床分辨两种疾病具有一定意义。     

Evidence that the interaction between circulating IgA and fibronectin is a normal process enhanced in primary IgA nephropathy

A solid-phase ELISA was set up to measure the direct binding capacity (BC) of different, commercially available, purified human IgA preparations to plates coated with human fibronectin (FN). It was found that secretory, polymeric, and, to a much lesser extent, monomeric IgA exhibited elevated FN-BC as compared to their BC to plates coated with bovine serum albumin. This binding was specific since not observed with human IgG or IgM antibodies. In addition, we noted that this interaction was dose dependent, Ca²⁺ dependent, saturable, and not covalent, was inhibited by soluble FN, but not by a prior incubation of FN-coated plates with anti-human fibronectin antibodies, and appeared to involve on the dimeric FN other structures than its heparin-binding, collagen-binding, or C1q-binding domains. Similar experiments conducted with normal plasma indicated that plasma IgA, but not plasma IgG or IgM, was also capable of significant binding to FN-coated plates. In contrast, serum IgA did not significantly bind to those plates under otherwise identical experimental conditions. Thus, the coagulation process induces a strong decrease in the FN-BC of circulating IgA, which implies the necessity of using plasma rather than serum to study such interactions. The apparent molecular weight of plasma IgA interacting with FN-coated plates ranged between 450 and 900 kd, and its major binding characteristics were quite similar to those observed with purified polymeric IgA. The FN-BC of plasma IgA was then measured by the same ELISA in 30 patients with primary IgA nephropathy (IgAN) and in 23 healthy controls. The mean FN-BC of plasma IgA was significantly higher in patients than in normal controls. This enhancement was due mainly to the augmentation in the concentration of circulating macromolecular IgA and was significantly correlated with the plasma levels of IgA-FN complexes. However, the pathogenetic role of these findings was probably not determinant since similar observations were made in alcoholic liver cirrhosis without urinary abnormalities and since the FN-BC of plasma IgA or the plasma levels of IgA-FN complexes were not correlated with the various biological parameters of evolutivity of primary IgAN. In conclusion, these studies suggest that the ability of polymeric IgA to directly bind to FN is involved in the formation of circulating IgA-FN complexes and that this normal binding process, although enhanced in IgAN, is probably not responsible for kidney injury, at least in the patients studied.     

Urinary IgA in IgA nephropathy and Henoch-Schoenlein purpura

To determine the concentrations and molecular forms of urinary IgA in IgA nephropathy and Henoch-Schoenlein purpura, we studied 29 patients with these IgA-associated renal diseases (IgAN). Control groups comprised 10 patients with other diverse renal diseases and 11 healthy volunteers. Urinary IgA and IgG concentrations were higher in IgAN than in either control group and correlated positively with the serum creatinine concentration as well as the urinary protein excretion (P<0.01). However, IgA/IgG ratios did not differ among the three groups. Polymeric IgA (p-IgA) in the urine predominated only in normals; in IgAN and patients with other renal diseases, monomeric IgA (m-IgA) occurred almost exclusively. Serum IgA concentrations were generally normal in IgAN; four patients had concentrations greater than 500 mg/dl. Although the fraction of p-IgA in serum (median, 18%) was increased above normal (5–10%) in 13 of 16 (81%) subjects, neither the concentration of IgA or IgG nor the amount of p-IgA correlated with the serum creatinine concentration. These data suggest that the molecular form and concentration of urinary IgA are not discriminating for IgAN and are independent of these characteristics of serum IgA.     

Clinico-pathological association of Henoch-Schoenlein purpura nephritis and IgA nephropathy in children

Objective: Henoch-Schonlein purpura nephritis (HSPN) and IgA nephropathy (IgAN) are similar syndromes. We aimed to determine whether the crescent formation/immunocomplex in glomeruli is associated with the differences of the biochemical indexes between HSPN and IgAN. Methods: We investigated the medical records of 137 HSPN cases and 41 IgAN cases from January 2009 to April 2014 in Nanjing Children’s Hospital of Nanjing Medical University. The clinical and pathological data were analyzed and compared between HSPN and IgAN. Results: HSPN patients had markedly higher levels of blood white blood cell (WBC), hemoglobulin (Hb) and platelet (PLT), lower levels of hematuria, blood nitrogen (BUN) and C4 compared with IgAN cases. Crescents formation and C3 deposition in the kidney did not affect these differences. Significantly lower levels of hematuria, blood IgG, IgM and C4 in HSPN compared with IgAN cases were observed among patients with IgG deposition. Markedly higher levels of WBC and Hb, lower levels of hematuria, creatinine (Cr), C4 in HSPN compared with IgAN cases were observed among patients with IgM deposition. No marked differences of the biochemical indexes were noted between HSPN and IgAN cases among patients with C1q deposition. Markedly higher levels of WBC and Hb, lower level of blood C4 in HSPN compared with IgAN cases were observed among patients with fibrogen deposition. Conclusions: The different levels of biochemical indexes at presentation between HSPN and IgAN may be associated with the deposition of IgG, IgM, C1q and fibrogen in the kidney.     

糖基化异常IgA1自身聚合或与IgG形成的大分子可能与IgA肾病病理表型相关

目的 IgA肾病是最常见的原发性肾小球疾病之一,其临床病理表型多种多样.血清中糖基化异常的IgA1及其与其他免疫球蛋白所形成的大分子复合物可能是本病重要的发病原因.本文探讨IgA1大分子复合物的组成和结构特征,及其与IgA肾病不同病理表型之间的关系.方法 制备偶联有去唾液酸IgA1（DesIgA1）和去唾液酸去半乳糖IgA1（DesDeGalIgA1）的琼脂糖亲和层析柱（DesIgA1/Sepharose,DesDeGalIgA1/Sepharose）.取10名轻度系膜增生性IgA肾病患者、10名局灶增生硬化性IgA肾病患者及10名正常人血清,分别经DesIgA1/Sepharose和DesDeGalIgA1/Sepharose分离,测定IgA1结合蛋白（IgA1-BP）含量及其中IgA1和IgG浓度,并检测IgA1-BP中IgA1糖基化程度,比较其在IgA肾病不同病理表型间的差别.结果 从两种亲和层析柱上所洗脱的IgA1-BP含量,在不同病理类型IgA肾病患者及正常人间无明显差别.在DesDeGalIgA1/Sepharose上洗脱的IgA1-BP中,两种病理类型IgA肾病患者IgA1唾液酸均严重缺失;在局灶增生硬化性IgA肾病患者中,IgA1分子半乳糖缺失比正常人严重.同时,局灶增生硬化性IgA肾病患者血清中与DesDeGalIgA1/Sepharose结合的IgG的含量显著多于正常人.结论 糖基化缺陷的IgA1自身聚合及与IgG聚合形成的大分子复合物可能与IgA肾病的病理表型相关.     

Low antibody affinity restricted to the IgA isotype in IgA nephropathy.

Antibody affinity affects the handling and behaviour of immune complexes, and experimental studies have shown that animals which produce predominantly low-affinity antibody are prone to immune complex deposition resulting in glomerulonephritis. In order to investigate the potential role of antibody affinity in the pathogenesis of IgA nephropathy, affinity of both IgA and IgG antibody isotypes during secondary response to systemic immunization with tetanus toxoid was studied in 20 patients with IgA nephropathy. Patients with IgA nephropathy produced IgA antibodies of significantly lower affinity than controls (P < 0.001), whereas IgG antibody affinities were similar. Contrasting with controls, patients' IgA antibody affinity was inversely related to antibody concentration, with higher responders producing large amounts of low-affinity antibody. IgG antibody affinity increased with time, and maturation of IgG antibody affinity was similar in both controls and patients. IgA affinity in controls decreased with time, and this lack of IgA affinity maturation may explain the relative unimportance of IgA in normal systemic immunity. This temporal decrease in IgA affinity was not observed in patients with IgA nephropathy. The production of low-affinity IgA in IgA nephropathy may provide an explanation for the predominant deposition of IgA in this disease.     

IgA nephropathy with subendothelial deposits

Summary IgA nephropathy with subendothelial deposits in the capillary walls of the glomeruli (IgA type 2) was compared histometrically and clinically with IgA nephropathy without subendothelial deposits (IgA type 1) and membranoproliferative glomerulonephritis with subendothelial deposits (MPGN). Study cases consisted of 32 biopsies from 26 patients of IgA type 1, 25 biopsies from 20 patients of IgA type 2 and 31 biopsies from 27 patients of MPGN. Histological changes of the glomeruli consisted of an increase in the mesangial matrix and hypercellularity in the mesangium in both types of IgA nephropathy, and the degree of the changes was a little higher in IgA type 2 than in IgA type 1 (0.02<P<0.05). Mesangial changes of MPGN were marked as compared with IgA type 1 and IgA type 2 (P< 0.001). Histometry of the mesangium on the cases followed up showed that the degree of mesangial thickening increased with lapse of time in IgA type 2 and MPGN, whereas it remained unchanged up to 13 years in IgA type 1. Proteinuria tended to be mild in IgA type 1, moderate in IgA type 2, and marked in MPGN. The impairment of renal function was observed in 21.9% of IgA type 1, in 36.0% of IgA type 2 and in 58.1% of MPGN. IgA type 2 has been shown to be pathologically and clinically intermediate between IgA type 1 and MPGN. These results suggest that there is a clinicopathological overlap between IgA nephropathy and MPGN with IgA deposition.     

IgA polyspecific autoantibodies in IgA nephropathy.

The specificity of circulating and kidney-bound IgA during IgA nephropathy is still a matter of discussion. In the present study, high levels of IgA antibodies directed against a panel of self and non-self antigens were found in the serum from patients with IgA nephropathy and were eluted from four out of the seven kidney biopsies studied. After immunoadsorption of pooled selected serum samples on TNP and actin-coated columns, polyspecific IgA antibodies were eluted. This supports the hypothesis that IgA-bearing B cells clones most probably producing polyspecific antibodies are a major feature of human IgA nephropathy. These findings also suggest that it may be hazardous to draw conclusions from the finding of apparently monospecific IgA antibodies in this condition.     

A case of sarcoidosis revealed in the course of IgA nephropathy

A 36 year old man, who had been proteinuric for 14 years due to immunoglobulin A (IgA) nephropathy, was admitted because of an acute exacerbation in renal dysfunction with hypercalcemia. He had presented with aortic regurgitation and increased pulmonary marking by chest X-ray, but laboratory examinations had failed to make an exact diagnosis, On admission, noncaseating epithelioid granulomas were disclosed by muscle and skin biopsies. Ophthalmological evaluation revealed old uveitis and retinal changes conslstent with sarcoidosis. In this case, IgA nephropathy was thought to be the initial manifestation of sarcoidosis that developed latently. Sarcoidosis should be considered in a differential diagnosis of IgA nephropathy.     

Binding capacity and pathophysiological effects of IgA1 from patients with IgA nephropathy on human glomerular mesangial cells

IgA deposition in glomerular mesangium and the interaction with mesangial cells may well be the final common pathway to IgA nephropathy (IgAN). Altered hinge-region O-glycosylation of IgA1 from patients with IgAN may predispose to mesangial deposition and activation of the mesangial cell (MC) by IgA1, via a novel IgA1 receptor, and may be a key event in the pathogensis of IgAN. The aim of this study was to investigate the binding capacity and biological effects of IgA1, from both patients with IgAN and healthy controls, on human mesangial cells (HMC). Serum IgA1 was isolated with jacalin affinity chromatography, heated to aggregated form (aIgA1) and labelled with (125)I. Binding capacity of aIgA1 in vitro to cultured primary HMC was evaluated by a radioligand binding assay and the specificity of binding was determined by a competitive inhibition assay. Intracellular calcium release was studied by confocal analysis and phosphorylation of extracellular signal-regulated kinase (ERK) was determined by Western blot analysis. Change of cell cycles was demonstrated by flow cytometry and HMC proliferation was evaluated by direct cell count. Expression of TGF-beta mRNA and production of supernatant fibronectin were tested by RT-PCR and indirect competitive ELISA, respectively. aIgA1 from both the patients with IgAN and normal controls bound to HMC in a dose-dependent, saturable manner, and was saturated at approximately 500 pmoles per 0.5 ml of aIgA1. aIgA1 from patients with IgAN, however, bound to HMC at a higher speed and Scatchard analysis revealed a Kd of (8.89 +/- 2.1) x 10(-8)m versus (4.3 +/- 1.2) x 10(-7)m for aIgA1 from healthy controls (P = 0.026).The binding was specific because it was only inhibited by unlabelled Mono-IgA1 (mIgA1) and not by serum albumin or IgG. aIgA1 from patients with IgAN could induce release of intracellular calcium, phosphorylation of ERK, DNA synthesis, proliferation of HMC, expression of TGF-betamRNA and secretion of fibronectin in HMC in a similar time-dependent manner as aIgA1 from healthy controls, but the effects were much stronger and the durations were much longer (P < 0.05, respectively). We conclude that aIgA1 from patients with IgAN has a higher binding capacity to HMC and stronger biological effects than aIgA1 from healthy controls. This suggests that direct interaction between IgA1 and HMC and subsequential pathophysiological responses may play an important role in the pathogenesis for IgAN.