Increased sensitivity of a new assay for anti-thyroglobulin antibody detection in patients with autoimmune thyroid disease

OBJECTIVES: To verify the cut-off values and to determine the clinical sensitivity of antithyroglobulin (TgAb) determinations using our routine RIA and the new electrochemiluminescent Elecsys assay. DESIGN AND METHODS: We used the DYNOtest anti-Tgn manual RIA from BRAHMS and the new automated Elecsys electrochemiluminescent immunoassay from Roche Diagnostics. We analyzed 452 sera from the following subjects: 193 euthyroid controls, 163 with treated and untreated autoimmune thyroid diseases (AITD) (108 Graves' disease and 55 thyroiditis), 50 with differentiated thyroid carcinoma, 13 with nonautoimmune thyroid disease and 33 with type 1 diabetes mellitus. RESULTS: As expected, using the proposed thresholds (BRAHMS 60 kIU/L, Elecsys 115 kIU/L) approximately 6% of the control subjects were positive for TgAb with both methods. In AITD patients, the sensitivity of TgAb determination was significantly higher with the Elecsys assay (51.5%) than with the BRAHMS assay (39.3%). This difference was not observed in the other patient groups. CONCLUSION: The Elecsys assay can be preferred not only because it is automated and rapid, but also because of its better clinical performance in AITD patients.     

Celiac disease occurring in a patient with hypoparathyroidism and autoimmune thyroid disease

Patients with an underlying autoimmune endocrine disorder are at an increased risk of developing other autoimmune diseases. We describe a patient with idiopathic autoimmune hypoparathyroidism who developed hyperthyroidism due to Graves disease and subsequently was diagnosed with celiac disease. Malabsorption of L-thyroxine was the only clue regarding the presence of celiac disease. This particular association of these three autoimmune disorders occurring in the same patient has not, to our knowledge, been previously reported. The presentation, investigations performed, and treatment provided are discussed and the literature pertaining to similar cases is reviewed.     

Assessment of antithyroglobulin and antimicrosomal autoantibodies in patients with autoimmune thyroid disease: comparison of haemagglutination assay, enzyme-linked immunoassay and radioligand assay

Four different assay systems for detection of antithyroglobulin (T-Ab) and thyroid antimicrosomal autoantibodies (M-Ab) were evaluated: two passive haemagglutination assays (PHA), an enzyme-linked immunoassay (ELISA) and a radioligand assay (RLA). Antibody levels measured with these methods correlated well (T-Ab: r = 0.72 to 0.88; M-Ab: r = 0.63 to 0.84; p less than 0.0001). However, when the results of the measured samples were classified as normal, slightly elevated and pathological, only 40-50% of the samples showed congruous results in all tests; 60-70% agreed in PHA and ELISA, whereas 80 to 90% corresponded in the two PHAs. RLA and ELISA gave more frequently positive results for T-Ab and negative results for M-Ab than the PHAs. Despite the lower sensitivity of the quantitative methods for M-Ab detection, they depicted more readily small changes after thyroxine treatment than the PHAs. We suggest that differences in autoantibody levels found with different methods may be due to autoantibody heterogeneity.     

Measurement of anti-thyroglobulin IgG in urine of patients with autoimmune thyroid diseases by sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay)

Anti-thyroglobulin IgG in urine of patients with Graves' disease and chronic thyroiditis and healthy subjects was measured by a sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay). Anti-thyroglobulin IgG in dialyzed urine was reacted simultaneously with 2,4-dinitrophenylated thyroglobulin and thyroglobulin-βT-D -galactosidase conjugate. The immune complex formed consisting of the three components was trapped onto polystyrene balls coated with (anti-2,4, dinitrophenyl group) IgG, eluted with ∈N-2,4-dinitrophenyl-L-lysine, and transferred onto polystyrene balls coated with (antihuman IgG γ-chain) IgG. β-D -Galactosidase activity bound to the last polystyrene balls was assayed by fluorometry. Anti-thyroglobulin IgG was detected in most of the patients, but not in most of the healthy subjects; levels of anti-thyroglobulin IgG in urine of the patients were well correlated to those in serum of the same patients. The measurement of anti-thyroglobulin IgG in urine by the immune complex transfer enzyme immunoassay was suggested to be useful as a diagnostic aid for autoimmune thyroid diseases. The conventional standard ELISA was not sufficiently sensitive for measuring anti-thyroglobulin IgG in urine. © 1993 Wiley-Liss, Inc.     

Autoantibody analysis of patients with graft versus host disease

The sera of 26 patients with graft versus host disease (GVHD) were analyzed for the presence of autoantibodies. Because the clinical spectrum of GVHD resembles some of the systemic collagen vascular diseases, particular attention was given to antinuclear antibodies and autoantibodies directed against saline soluble cellular antigens. 39% (10/26) of the patients had a positive ANA at a titer of greater than or equal to 1/80. Antibodies to double-stranded DNA were demonstrated in 4 sera (15%), to smooth muscle in 9 (41%) and to nucleoli in 6 (22%). Three sera had precipitating antibodies to saline extracts of rabbit thymus and/or bovine spleen. None of these precipitins showed lines of identity with known autoantibody systems. High titers of ANA were correlated with a previous diagnosis of acute lymphoblastic leukemia and multiple autoantibodies correlated with the severity of GVHD.     

Improved measurement of anti-thyroglobulin IgG in urine of patients with autoimmune thyroid diseases by sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay)

Previously, antithyroglobulin IgG was assayed in dialyzed urine from patients with autoimmune thyroid diseases by a sensitive enzyme immunoassay (immune complex transfer enzyme immunoassay), and most of the assay results were useful as a diagnostic aid for autoimmune thyroid diseases. However, dialysis of urine was laborious and time-consuming, and some results were less reliable due to low levels of anti-thyroglobulin IgG in urine. This paper describes some improvements of the assay. Useful assay results could be obtained for most of urine samples without dialysis, although some interfering substance(s) was suggested to be present in some urine samples before dialysis. Accurate assay results with no interference could be obtained after gel filtration by only two min centrifugation in place of dialysis. More reliable assay results for urine samples containing low levels of antithyroglobulin IgG were obtained after concentration using a molecular sieve. © 1993 Wiley-Liss, Inc.     

225例肝病患者自身抗体检测结果分析

目的：探讨各种肝病患者中自身抗体检测在自身免疫性肝病（autoimmune liver disease, ALD）包括自身免疫性肝炎（autoimmune hepatitis, AIH）、原发性胆汁性肝硬化（primary biliary cirrhosis, PBC）及原发性硬化性胆管炎（primary sclerosing cholangitis, PSC）中的临床意义。方法选择我院2013年1月-2014年2月消化科、肝胆外科、移植外科等收治的各种肝病患者225例,分为ALD患者组和其他肝病患者组。用间接免疫荧光法检测225份临床血清标本中抗核抗体（antinuclear antibody, ANA）、抗平滑肌抗体（antismooth muscle antibody, SMA）和抗线粒体抗体（anti-mitochondrial antibody, AMA）,用欧蒙印迹法检测抗肝肾微粒体抗体（liver kidney microsomal, LKM）、抗肝细胞溶质抗原Ⅰ型抗体（liver cytosol-1, LC-1）、抗可溶性肝抗原抗体/抗肝胰抗体（anti-soluble liver antigen antibody/liver pancreas antigen, SLA/LP）、AMAⅡ型（AMA-M2）并查阅临床资料,对检测结果作出分析。结果 ALD 患者组ANA阳性率为77．78％,SMA阳性率为7．41％,AMA阳性率为55．56％,LKM 阳性率为7．41％,AMA-M2阳性率为48．15％,SLA/LP 阳性率为7．41％,LC-1阳性率为3．70％。其他肝病患者组 ANA 阳性率为26．26％,SMA 阳性率为4．55％,AMA 阳性率为11．11％,LKM 阳性率为0．51％,AMA-M2阳性率为5．05％,SLA/LP阳性率为2．53％,LC-1阳性率为1．52％。ALD患者组自身抗体阳性率与其他肝病患者组相比较,ANA、AMA、LKM、AMA-M2差异均有统计学意义（P均＜0．05）。结论 ALD患者自身抗体检出率较高,为临床医生鉴别病毒性肝炎、ALD及其他肝病提供可靠依据。     

自身免疫性甲状腺病患者放免法测定TPOAb及其临床评价

为探讨甲朱过氧化物酶抗体不同测定方法结果的差异性及其意义，以免疫亲和纯化的ＴＰＯ制备ＴＰＯ单克隆抗体兔抗人ＴＰＯ抗血清，建立了测定ＴＰＯＳＡｂ的三种方法：液相双抗法ＲＩＡ、单抗固相ＲＩＡ及液相竞争ＲＩＡ。     

自身免疫性甲状腺疾病伴烟雾综合征七例并文献复习

目的分析和探讨自身免疫性甲状腺疾病合并烟雾综合征(MMS)的临床特点及可能发病机制。方法总结北京天坛医院2007年至2011年于神经外科经数字减影血管造影(DSA)及磁共振血管成像(MRA)检查诊断为MMS的患者7例,所有患者经内分泌科确诊伴随自身免疫性甲状腺疾病,并除外血管狭窄的其他常见原因。结果 7例患者中,男2例,女5例。其中5例伴有Graves病,2例伴有桥本甲状腺炎;甲状腺功能亢进患者6例,甲状腺功能减退患者1例。6例患者TPOAb增高,4例患者TRAb阳性,5例患者TGAb增高。7例患者均为典型的颈内动脉末端(TICA)、大脑中动脉(MCA)、大脑前动脉(ACA)狭窄或闭塞,5例患者颅底可见烟雾状血管网,2例合并双侧大脑后动脉(PCA)狭窄。7例患者中6例甲状腺功能亢进患者经口服他巴唑联合颞浅动脉-大脑中动脉搭桥手术治疗,1例甲状腺功能减退患者经口服优甲乐联合颞浅动脉-大脑中动脉搭桥手术治疗。所有7例患者术中及术后未见手术并发症,恢复良好后出院。结论自身免疫性甲状腺疾病合并MMS可能与甲状腺功能异常及自身免疫反应等因素相关;MMS患者常规行甲状腺功能及抗体筛查十分必要;积极治疗甲状腺疾病是手术治疗MMS的重要基础。     

Autoantibody facilitated cleavage of C1-inhibitor in autoimmune angioedema.

C1-inhibitor (C1-Inh) is an important inhibitor of the inflammatory response and deficiency of this inhibitor, which may be hereditary or acquired, is associated with recurrent episodes of edema. Recently, an autoimmune form of angioedema has been described that is associated with functional deficiency of C1-Inh and an autoantibody that impedes C1-Inh function. In this report we describe the isolation of C1-Inh from the monocytes and plasma of a patient with autoimmune angioedema and demonstrate that the patient's monocytes secrete structurally and functionally normal C1-Inh, but show that this protein circulates in the patient's plasma in an inactive, structurally altered form. Furthermore, using analytic gel electrophoresis techniques it is demonstrated that the patient's autoantibody facilitates cleavage of normal C1-Inh, by its target proteases, to the same species of C1-Inh that is found circulating in the patient's plasma. This autoantibody facilitated cleavage of normal C1-Inh is apparently a consequence of destabilization of protease/inhibitor complexes. These findings contribute to our understanding of protease/C1-Inh interactions and document important observations on pathogenic mechanisms in autoimmune disease.     

Biological variability of thyroid autoantibodies (anti-TPO and anti-Tg) in clinically and biochemically stable patients with autoimmune thyroid disease

The biological variation of anti-TPO and anti-Tg autoantibodies was studied in 17 clinically and biochemically stable female patients with autoimmune thyroid disease (AITD), at regular monthly intervals over a period of 6 consecutive months. The mean and standard deviation (SD), within-subject coefficient of variation (CV), between-subject CV, index of individuality, reliability coefficient, and critical differences were as follows: for anti-TPO 238 (197) U/ml, 9.2%, 81.4%, 0.11, 0.96, and 27.6%; and for anti-Tg 1,785 (3,170) U/ml, 6.9%, 174%, 0.04, 0.99, and 22.3%. The data indicate a low within-subject CV, and a high between-subject CV that is particularly pronounced for anti-Tg. The high individuality of both autoantibodies indicates that an isolated result compared to conventional population-based reference intervals is of very little value for diagnosis. Furthermore, the near to 1 reliability coefficient for both autoantibodies correctly classifies the patient with respect to his or her homeostatic mean antibody concentration in a 6-month period of clinical and biochemical stability of thyroid disease. Imprecision goals for anti-TPO and anti-Tg antibodies are attainable with current methodology.     

1型糖尿病合并自身免疫性甲状腺疾病患者临床特征和外周血相关血细胞因子表达水平的研究

目的：检测1型糖尿病合并自身免疫性甲状腺疾病（AITD）胰岛相关抗体及甲状腺相关抗体阳性率及其外周血Th1、Th2、Th17、Treg相关细胞因子表达水平,分析1型糖尿病合并AITD临床特点,探讨各细胞因子在1型糖尿病发生发展中的作用。方法收集1型糖尿病患者63例,对照组为来我院健康体检者57例,采集静脉血,检测胰岛相关抗体、甲状腺相关抗体及IFN-γ、IL-4、IL-10、IL-17细胞因子表达水平。结果1型糖尿病组 IFN-γ及 IL-17表达水明显高于正常对照组[（400.95±51.44）pg/ml vs.（340.99±39.47）pg/ml,P＜0.01;（26.87±±2.47）pg/ml vs.（19.41±2.80）pg/ml,P＜0.01],IL-4及IL-10表达水平均低于正常组[（21.63±4.22）pg/ml vs.（31.49±2.42）pg/ml,P＜0.01;（15.69±3.22）pg/ml vs.（24.13±2.17）pg/ml,P＜0.01],差异均有统计学意义。1型糖尿病任一胰岛相关抗体阳性组,TPO-Ab、TG-Ab、TR-Ab阳性率均高于胰岛相关抗体阴性组,差异有统计学意义（P＜0.05）,但各细胞因子表达无明显差异。1型糖尿病患者血清IL-17水平与HbA1c水平正相关（r＝0.59,P＜0.05）。结论1型糖尿病患者CD4＋T细胞各亚群间平衡失调,Th1/Th2及Th17/Treg平衡失调,向Th1及Th17方向漂移,细胞免疫及IL-17介导的前炎症反应在1型糖尿病起病中发挥主要作用,1型糖尿病胰岛相关抗体阳性患者,具有更高的甲状腺相关抗体阳性率,可能具有更高的自身免疫性甲状腺疾病风险。     

系统性红斑狼疮伴自身免疫性甲状腺病的临床分析

目的探讨系统性红斑狼疮(systemic lupus erythematosus,SLE)伴发自身免疫性甲状腺病(autoimmune thyroid-ism disease,AITD)和甲状腺抗体的情况。方法采用放射免疫分析法测定100例SLE患者中甲状腺激素水平及血清甲状腺微粒体抗体(TMAb)和甲状腺球蛋白抗体(TGAb)水平。结果 100例SLE患者有9例(9%)伴发AITD,其中甲状腺功能减退6例,甲状腺功能亢进2例,亚急性甲状腺炎1例;伴发AITD的SLE患者出现甲状腺抗体的阳性率高于未伴发AITD的患者(P=0.000),合并甲状腺功能减退患者TMAb阳性率高于TGAb阳性率。结论 SLE患者甲状腺功能减退的发生率为6%,AITD发生率远高于普通人群0.4%,SLE伴发AITD并不少见,应重视甲状腺功能和甲状腺抗体的检测。     

慢性扁桃体炎患者甲状腺自身免疫状态的临床分析

目的:检测反复发作的慢性扁桃体炎患者的甲状腺自身抗体,分析甲状腺自身免疫性疾病患病率,探讨慢性扁桃体炎与甲状腺自身免疫的关系。方法:以慢性扁桃体炎患者女122例(炎症女组)、男105例(炎症男组)为研究对象,以同龄、无慢性扁桃体炎体检者女172例(非炎症女组)、男146例(非炎症男组)为对照组,进行回顾性分析。检测并对比分析炎症男、女组与相应非炎症组之间甲状腺球蛋白抗体(thyroglobulin antibody,TgAb)、甲状腺过氧化物酶抗体(thyroid peroxidase antibody,TPOAb)、促甲状腺激素受体抗体(thyroid-stimulating hormone receptor antibody,TRAb)等甲状腺自身抗体阳性率的不同;进一步对比分析炎症男、女组与相应非炎症组之间慢性淋巴细胞性甲状腺炎(chronic lymphocytic thyroiditis,CLT)、毒性弥漫性甲状腺肿(Graves disease,GD)等甲状腺自身免疫性疾病患病率的不同;对比分析炎症男、女组与相应非炎症组之间甲状腺功能异常率的不同。结果:炎症男、女组TgAb、TPOAb的阳性率(男:14.3%,30.5%;女:30.3%,40.2%)明显高于相应非炎症组(P0.05);炎症男、女组TRAb的阳性率(2.9%、4.1%)与相应非炎症组比较差异无统计学意义。炎症男、女组CLT患病率(16.2%、25.4%)明显高于相应非炎症组的患病率(P0.01);炎症男、女组GD患病率(2.9%、4.1%)与相应非炎症组比较差异无统计学意义。炎症男、女组亚临床甲状腺功能减退(亚甲减)的患病率(21.9%、27.9%)均明显高于相应非炎症组(P0.01);炎症女组临床甲状腺功能减退(甲减)的患病率(6.6%)明显高于非炎症女组(P0.05)。炎症男、女组亚临床甲状腺功能亢进(亚甲亢)、临床甲状腺功能亢进(甲亢)的患病率及炎症男组甲减的患病率与相应非炎症组比较差异均无统计学意义。结论:慢性扁桃体炎患者甲状腺部分自身抗体阳性率、CLT患病率、甲状腺功能异常率均明显增高,提示慢性扁桃体炎反复发作与甲状腺自身免疫损伤有相关性。     

Autoantibody against diiodinated tyrosine-gastrin in a patient with Graves' disease

We describe autoantibodies against iodinated gastrin in a patient with Graves' disease. Values for serum gastrin differed in this case, depending on which of two different radioimmunoassay (RIA) kits was used. RIA with the dextran-coated charcoal method for separation of free tracer gastrin gave a value less than 9.5 pmol/L, whereas the value by a RIA kit by the double-antibody method was 318 pmol/L. The patient's serum contained a binding protein for 125I-labeled gastrin, as detected by Sephadex G-200 column chromatography. The IgG fraction was responsible for the ability of serum to bind 125I-labeled gastrin. Interestingly, of the two possible forms of iodinated gastrins, monoiodinated (MIT) and diiodinated (DIT) tyrosine-125I-labeled gastrin, only the latter bound to patient's IgG. Furthermore, DIT-gastrin, but not gastrin or MIT-gastrin, inhibited the binding of DIT-125I-labeled gastrin. The patient's serum evidently contains autoantibodies against DIT-gastrin that interfere with RIA of gastrin.