HLA Antigens in Insulin-Dependent Diabetes Mellitus

Diabetes mellitus is largely determined by genetic factors but environmental factors are necessary to convert genetic susceptibility into overt disease. Studies of twins show that the genetic impact in non-insulin-dependent diabetes mellitus is stronger than in insulin-dependent diabetes mellitus. The genetic factors involved in non-insulindependent diabetes mellitus are not known and the outcome of molecular genetic research has so far been disappointing. The major genetic susceptibility to insulindependent diabetes mellitus is conferred by genes in the HLA region on chromosome 6. Despite many advances in molecular genetics in insulindependent diabetes mellitus the serologically detectable HLA antigens and haplotypes are still the best available markers. This review describes the important developments in immunogenetics in insulindependent diabetes mellitus and summarises the main findings from earlier studies. Genetically the potential for primary prevention of insulin-dependent diabetes mellitus already exists and will become a reality as soon as the environmental determinants are identified. A wide application of immunogenetic methods will be needed in the prevention of insulin-dependent diabetes mellitus.     

DQA1 and DQB1 Heterodimers in Insulin-dependent Diabetes Mellitus: A Genetic-epidemiological Study in Finland

Susceptibility to insulin-dependent diabetes mellitus (IDDM) correlates with the absence of aspartic acid in position 57 of the DQB1 and/or the presence of arginine in position 52 of the DQA1. It has been postulated that transcomplementation between the DQ alpha and beta chains of the two haplotypes could create new molecules conferring susceptibility to IDDM.

Finland has the highest incidence of IDDM in the world (35/100,000). In a nationwide study of IDDM in childhood (DiMe study) HLA genotyping using conventional serology was carried out according to genetic-epidemiological principles.

We simulated DQA1 and DQB1 alleles in 707 consecutively diagnosed IDDM probands and 98 non-diabetic children based on serology, restriction fragment length polymorphism results and sequence data assuming no recombination between DQ and DR.

In 34% of Finnish children with IDDM all four combinations (two in cis and two in trans) could lead to SS heterodimers. Two-thirds of these combinations were explained by DR3, DR4 heterozygotes. In 50% of IDDM children half and in 11% a quarter of the combinations could lead to heterodimers. In 38 IDDM patients (5%) the formation of hybrid molecules was not possible. In 59% of the controls SS heterodimers were possible and should therefore have an underlying genetic susceptible for IDDM assuming the theory of transcomplementation is correct. These findings, together with the fact that the lowest frequency of DR3, DR4 heterozygosity (21%) was seen in Finland, show that heterozygosity for DQ and DR cannot explain the differences seen in IDDM incidence.     

Role of Epinephrine-mediated β-Adrenergic Mechanisms in Hypoglycemic Glucose Counterregulation and Posthypoglycemic Hyperglycemia in Insulin-dependent Diabetes Mellitus

Initially euglycemic (overnight insulin-infused) patients with insulin-dependent diabetes mellitus (IDDM), compared with nondiabetic controls, exhibit similar, but somewhat delayed plasma glucose nadirs, delayed glucose recovery from hypoglycemia, and posthypoglycemic hyperglycemia after the rapid intravenous injection of 0.075 U/kg of regular insulin. These abnormalities are associated with and potentially attributable to markedly diminished glucagon secretory responses, partially reduced epinephrine secretory responses and delayed clearance of injected insulin in the diabetic patients. Because glucagon normally plays a primary role in hypoglycemic glucose counterregulation and enhanced epinephrine secretion largely compensates for glucagon deficiency, we hypothesized that patients with IDDM, who exhibit diminished glucagon secretory responses to hypoglycemia, would be more dependent upon epinephrine to promote glucose recovery from hypoglycemia than are nondiabetic persons. To test this hypothesis, glucose counterregulation during beta-adrenergic blockade with propranolol was compared with that during saline infusion in both nondiabetic controls and in patients with IDDM. Glucose counterregulation was unaffected by beta-adrenergic blockade in controls. In contrast, glucose recovery from hypoglycemia was significantly impaired during beta-adrenergic blockade in diabetic patients. This finding confirms the hypothesis that such patients are more dependent upon epinephrine-mediated beta-adrenergic mechanisms to promote glucose recovery from hypoglycemia and indicates that the measured deficiency of glucagon secretion is functionally important in patients with IDDM. Further, in the time frame of these studies, posthypoglycemic hyperglycemia was prevented by beta-adrenergic blockade in these patients. There was considerable heterogeneity among the diabetic patients with respect to the degree to which beta-adrenergic blockade limited the posthypoglycemic rise in plasma glucose. This rise was directly related to the degree of residual glucagon secretion and inversely related to plasma-free insulin concentrations.THUS, WE CONCLUDE: (a) that patients with IDDM are, to varying degrees, dependent upon epinephrine-mediated beta-adrenergic mechanisms to promote glucose recovery from hypoglycemia and that the degree of this dependence upon epinephrine is an inverse function of the residual capacity to secrete glucagon in response to hypoglycemia in individual patients; (b) that sympathoadrenal activation, coupled with the inability to secrete insulin, plays an important role in the pathogenesis of posthypoglycemic hyperglycemia in patients with IDDM.     

滤泡辅助性T细胞参与结缔组织病的发病机制

滤泡辅助性T(T follicular helper,Tfh)细胞是CD4+T淋巴细胞的一个子集,定位于淋巴滤泡,具有辅助B细胞的功能。它参与生发中心(germinal center,GC)的形成和B细胞的发育并调控其功能。Tf h细胞发育和功能障碍可导致免疫系统紊乱,引起多种结缔组织病发生。明确Tf h细胞参与结缔组织病的发病机制,可更加全面地认识结缔组织病,为该病种提供靶向Tfh细胞治疗的新途径。     

外周血循环microRNA与糖尿病的研究进展

糖尿病日渐成为了当今仅次于心脑血管病和肿瘤的第三类高度威胁人类健康的疾病,研究证明外周血中存在的微小RNA（microRNA,miRNA）与糖尿病的发生与发展密切相关。由于循环 miRNA检测具有无创性、可重复性等自身特性,决定其对各类糖尿病的诊断和预后评估具有广阔的应用前景。该文初步介绍循环 miRNA的来源与特性,特别是国内外研究循环miRNA作为糖尿病诊断标志物的进展,为进一步深入研究奠定基础。     

HLA氨基酸三维构象差异在非血缘造血干细胞移植中的作用分析

本研究探讨HLA氨基酸三维构象软件在评价不同HLA构象对造血干细胞移植预后的作用.回顾分析62例北京市道培医院单中心非血缘造血干细胞移植(30例HLA等位基因10/10全合和32例HLA等位基因9/10相合).应用Histocheck和HLA-Matchmaker 2个HLA抗原三维空间构象分析软件,分析其评分系统与移植后1年总生存率、急性GVHD和复发率的相关性.结果表明:①随着Histocheck软件的评分的增加Ⅲ-Ⅳ度GVHD的发生率增加(0%增加到20%,p=0.25),但是高分组中仍有70%病例没有或只有轻度GVHD.对移植后的复发进行统计,除Histocheck分数偏高组(11-20)9例没有复发,其它组复发率差别不大(20%左右),(p=0.56).②应用HLA-Matchmaker软件分析,随着供受者Eplet差异数目的增加,重度GVHD的发生率明显增加(0%增加到30%),无或轻度GVHD的发生率下降(p=0.019),但高分组中仍有60%没有或只有轻度GVHD,统计学有差异.差异数目偏高组(≥3)共10例均没有复发,偏低组(＜3)复发率偏高(20%左右p=0.54).结论:Histocheck和HLA-Matchmaker两个分析软件虽然对于HLA抗原构象差异的计算方法不同,但结果有很多的相近性.对于同一组供受者,两个给分系统与急性GVHD和复发的相关性类似,高分组中重度GVHD的比例增加,复发率下降,但相关性都不准确.HLA-Matchmaker软件的相关性略好于Histocheck.     

Loss of functional suppression by CD4+CD25+ regulatory T cells in patients with multiple sclerosis

CD4+CD25+ regulatory T cells contribute to the maintenance of peripheral tolerance by active suppression because their deletion causes spontaneous autoimmune diseases in mice. Human CD4+ regulatory T cells expressing high levels of CD25 are suppressive in vitro and mimic the activity of murine CD4+CD25+ regulatory T cells. Multiple sclerosis (MS) is an inflammatory disease thought to be mediated by T cells recognizing myelin protein peptides. We hypothesized that altered functions of CD4+CD25hi regulatory T cells play a role in the breakdown of immunologic self-tolerance in patients with MS. Here, we report a significant decrease in the effector function of CD4+CD25hi regulatory T cells from peripheral blood of patients with MS as compared with healthy donors. Differences were also apparent in single cell cloning experiments in which the cloning frequency of CD4+CD25hi T cells was significantly reduced in patients as compared with normal controls. These data are the first to demonstrate alterations of CD4+CD25hi regulatory T cell function in patients with MS.     

急性移植物抗宿主病发生过程中供者T细胞迁移和归巢的机制

供者T细胞向次级淋巴器官的迁移以及活化的供者T细胞向急性移植物抗宿主病（aGVHD）靶器官的迁移归巢是aGVHD发生的关键环节之一,深入认识供者T细胞的归巢机制对aGVHD的防治具有重要意义。本文就供者T细胞向次级淋巴器官的迁移,活化的供者T细胞向aGVHD靶器官的归巢,供者调节性T细胞向aGVHD靶器官的归巢和aGVHD过程中T细胞迁移归巢机制及其研究前景等进行了综述。     

Binding of anti‐HLA class I antibody to endothelial cells produce an inflammatory cytokine secretory pattern

Current methods are inadequate for the diagnosis of early chronic allograft rejection. The goal of this study was to determine whether ligation of anti‐HLA antibodies to endothelial cells is associated with a distinctive cytokine secretory pattern. Human iliac artery endothelial cells (HIAEC) cultured in vitro were incubated with w6/32, an anti‐HLA class I mAb. Culture supernatants collected daily for up to 4 days were tested for secretion of 13 cytokines using a multiplexed fluorescent microsphere immunoassay. Culture of HIAEC with medium containing mAb w6/32 supported the growth of HIAEC during the 4‐day study period. Levels of the pro‐inflammatory cytokines IL‐1β, IL‐6, IL‐8, and TNF‐α became significantly increased in supernatants of HIAEC incubated with the mAb w6/32. We conclude that ligation of anti‐HLA class I antibodies to HLA class I antigens in endothelial cells initiates an acute inflammatory process and detecting an inflammatory cytokine secretory pattern might be useful to diagnose sub‐clinical chronic allograft rejection. J. Clin. Lab. Anal. 23:157–160, 2009. © 2009 Wiley‐Liss, Inc.     

中华骨髓库HLA分型质控工作中分型结果错误原因的分析及探讨

目的对中国造血干细胞捐献者资料库（简称中华骨髓库）中人类白细胞抗原（HIA）分型数据质控抽枪中发现的错误分型情况进行归纳总结，探讨其产生的原因及解决策略，以提高造血干细胞捐献者HLA分型的准确性。方法采用聚合酶链反应（PCR）-序列特异件引物（sequence specific primers, SSP） 、PCR-序列特异性寡核苷酸探针（sequence specific oligonucleotide probes, SSOP）及基因测序（ sequence based typing,SBT）分型方法，对中华骨髓库按比例随机抽取的7313份已完成HLA-A、B、DRB1基因分型的标本进行复检，使用与所抽检标本原始分型试剂小同的试剂盲检，对结果不符者，采用第3种试剂及其原始分型试剂复检；对于难以确定的结果，采用SBT方法确认。采用直接计数法进行HLA差错统计。结果质控抽检6期共7313份标本，发现HLA分型结果错误标本数183份，平均错误率为2．50％。HLA基因分型错误率逐年降低，6期错误率分别为8．18％、3．84％、2．85％、1．70％、1．10％、0．84％。HLA-A位点错误率为0．49％，其中漏检现象占A位点错误的61．11％；HLA-B位点错误率为0．85％，其中以同一宽特异性组之间的业型判断错误者居多，占B位点错误的41．94％；HLA-DRB1位点错误率为0．66％；另外，可能由于标本搞错导致的HLA-A、B、DRB1 3个位点分型全错有41例，错误率为0．56％。结论错误产生的原因有实验人员的技术操作水平及工作责任心上的原因，也有分型方法及试剂本身的原因。采用DNA分型技术，使用特异性、重复性好的合格试剂及加强质控监督，有助于提高HLA分型的准确性，并将有助于提高骨髓库造血干细胞捐献者HLA分型的质量。     

Opportunities and limitations of mouse models humanized for HLA class II antigens

Summary.  MHC class II molecules are essential for shaping the CD4+ T-cell repertoire in the thymus and for selecting antigenic peptides that are presented to CD4+ T cells in the periphery. A range of different mouse models humanized for HLA class II antigens have been developed to study the regulation of MHC-class II restricted immune responses. These mouse models have been used to identify immunodominant peptides that trigger diseases and to characterize the interactions of T-cell receptors with disease-associated peptides and MHC class II molecules. Peptides presented to CD4+ T cells in these mouse models were shown to be similar to peptides presented to CD4+ T cells in patients who carry the same MHC class II haplotype. Opportunities and limitations associated with these mouse models will be discussed and the potential application of these models for understanding the regulation of antibody responses against factor VIII in hemophilia A will be indicated.     

HLA配型、PRA检测在心脏移植中的应用研究

目的：探讨人类白细胞抗原（human leukocyte antigen，HLA）配型、群体反应性抗体（panel reactive antibody，PRA）与心脏移植术后急性排斥反应及近期生存的关系。方法：将心脏移植受者根据不同的HLA配型标准，按错配数分组；根据PRA检测阳性或阴性分组。统计各组术后3、6、12个月内急性排斥反应发生率并行生存分析。结果：HLA配型不同错配数组间急性排斥反应发生率及生存曲线无显著差异；PRA阳性和阴性组间急性排斥反应发生率及生存曲线也无显著差异。结论：就我国目前国情而言，心脏移植术前不进行常规HLA配型也是可行的，PRA阳性者通过适当的干预治疗也可获得安全的移植。     

人类白细胞抗原（HLA）基因分型在造血干细胞移植中的应用

目的提高造血干细胞移植供、受者HLA配型的精确度，有效防止移植物抗宿主病Graft—vs host disease（GVHD）的发生。方法采用准确、简便的DNA提取方法和PCR—SSP基因分型方法。建立HLA—A，B，DR基因分型方法。结果对167例临床标本进行基因水平的研究发现。DNA提取方法可以满足此项研究对样本的要求。HLAPCR—SSP基因分型方法具有良好的稳定性、可靠性和特异性。结论HLA基因分型方法准确、特异、重复性好．可作为临床造血干细胞移植配型和正常人群无关供者筛选的常规方法。对（GVHD）的发生必将起到重要的预防作用。     

International Variations in Cardiovascular Mortality Associated with Diabetes Mellitus: The WHO Multinational Study of Vascular Disease in Diabetes

The WHO Multinational Study of Vascular Disease in Diabetes was launched in 1975–77 to investigate international variations in the occurrence of different manifestations of vascular disease in subjects with insulin-dependent and non-insulin-dependent diabetes. A morbidity and mortality follow-up extending until January 1, 1988 was carried out in 10 centres, including five European centres (London, Switzerland, Berlin, Warsaw and Zagreb), two East Asian centres (Hong Kong and Tokyo), two Native American centres (Arizona and Oklahoma) and one Caribbean centre (Havana). Of a total of 4714 diabetic subjects (2310 men and 2404 women) aged between 35 and 55 years at baseline who were successfully followed up, 1266 were classified as having insulin-dependent diabetes and 3448 as having non-insulin-dependent diabetes. There was a large variation between the centres in ischaemic heart disease and cerebrovascular disease mortality rates for both insulin-dependent and non-insulin-dependent diabetic subjects, presumably reflecting in part differences between the background populations in mortality rates from these cardiovascular causes. The lowest ischaemic heart disease mortality rates for diabetic subjects were observed in Hong Kong and Tokyo centres, representing industrialized countries which have continued to have low Ischaemic heart disease mortality rates. The importance of raised blood pressure and proteinuria as potentially modifiable cardiovascular risk factors in diabetic subjects was confirmed in this study.     

1400例糖尿病患者血清胰岛相关抗体检测的临床意义

目的观察胰岛细胞抗体(ICA)、胰岛素自身抗体(IAA)、谷氨酸脱羧酶抗体(GAD-A b)在1型、2型糖尿病(DM)和正常人群中阳性检出率,并探讨其临床意义。方法用EL ISA法检测血清ICA、IAA、GAD-A b。结果1、2型DM患者和正常人群血清中,ICA阳性率分别为39.0%,12.6%,3.8%;IAA阳性率分别为31.9%,16.3%,2.9%;GAD-A b阳性率分别为55.5%,16.8%,0.4%。结论结果提示ICA、IAA、GAD-A b与1型DM的发病高度相关;这些抗体的出现预示β细胞功能受损,有助于从2型DM中及早发现成人隐匿性自身免疫性糖尿病(LADA),以利临床早期应用胰岛素治疗,从而延缓胰岛β细胞功能的衰竭。     

通心络对糖尿病患者血管内皮损伤的影响

目的研究通心络胶囊对糖尿病患者血管内皮细胞功能的影响。方法随机将60例糖尿病（DM）患者分为常规治疗组（30例）和通心络治疗组（30例）,后者在糖尿病常规降糖治疗的基础上加用通心络治疗,治疗8周,观察两组用药前后vonWille-brand因子（vWF）、超氧化物歧化酶（SOD）、血糖、血脂等指标的变化。结果治疗后,通心络治疗组vWF明显低于常规治疗组（P〈0.01）,SOD明显高于常规治疗组（P〈0.01）,血脂明显低于常规治疗组（P〈0.01）。结论通心络能够减轻DM患者的血管内皮细胞的损伤,可以预防和延缓糖尿病并发症的发生和发展。