A differential association of interferon-gamma high-producing allele T and low-producing allele A (+874 A/T) with Hashimoto's thyroiditis and Graves' disease

Cytokines play a crucial role in the pathogenesis of autoimmune thyroid disease. The aim of this study was to investigate the relationship of the single base change polymorphic variants identified in the first intron of interferon-gamma (IFN-gamma) (+874 T/A) with susceptibility to thyroid dysfunctions. A total of 340 subjects were included in the study comprising of 190 patients (104 patients with Hashimoto's thyroiditis, 26 with non-Hashimoto's hypothyroidism and 60 Graves' disease) and 150 controls. Genotyping was done by amplification refractory mutation system-polymerase chain reaction using a set of sequence-specific primers. Statistical analysis revealed a significant association between high IFN-gamma-producing genotype TT and Hashimoto's thyroiditis compared to controls (P value < 0.001). On the other hand, the frequency of genotype TT was decreased in patients with Graves' hyperthyroidism with a significant increase in low IFN-gamma-producing genotype AA among this group (P = 0.03). To conclude the results of the study suggest a differential association of high- and low-producing alleles of IFN-gamma gene with Hashimoto's thyroiditis and Graves' disease. The high IFN-gamma-producing allele T was observed to be associated with Hashimoto's thyroiditis in the present study where as in Graves' hyperthyroidism the association was observed to be stronger with the low producing allele A.     

凋亡相关因子参与自身免疫性甲状腺疾病发病的研究

目的:了解细胞凋亡相关蛋白Fas,FasL和Bcl-2表达在自身免疫性甲状腺疾病发病机制及病理变化中的作用及意义。方法:采用免疫组织化学方法,检测20例桥本甲状腺炎,20例Graves病以及20例甲状腺腺瘤(作为对照组)患者甲状腺标本中Fas、FasL和Bcl-2表达及分布。结果:Fas在所有的标本中表达,主要分布于甲状腺滤泡细胞表面和细胞质上。除3例甲状腺瘤标本外,其余均表达FasL。Bcl-2表达于15例桥本甲状腺炎、19例Graves病以及17例甲状腺瘤滤泡细胞上。在甲状腺瘤滤泡细胞上表达中等强度Fas,很少或是没有表达FasL。在桥本甲状腺炎中Fas和FasL免疫染色强阳性甲状腺滤泡细胞多分布于浸润淋巴滤泡附近,浸润淋巴细胞中Fas、FasL免疫染色相对较弱。在Graves病中,Fas表达强度与桥本甲状腺炎类似,但FasL表达却更弱。在Graves病和甲状腺瘤组织中,Bcl-2表达两者类似。但在桥本甲状腺炎组织中,分布于浸润淋巴细胞附近的甲状腺滤泡细胞以及生发中心的淋巴细胞上,Bcl-2表达很弱。结论:Fas、FasL和Bcl-2表达在桥本甲状腺炎和Graves病中相似。FasL高表达和Bcl-2低表达可能引起桥本甲状腺炎滤泡细胞凋亡。进一步证明3种凋亡相关因子在自身免疫性甲状腺疾病发病机制中的作用。在桥本甲状腺炎中,滤泡细胞凋亡并非由浸润淋巴细胞其FasL发挥作用直接杀伤,但是它们能分泌细胞因子促进滤泡细胞自身Fas、FasL表达,从而导致滤泡细胞凋亡。     

Analysis of the expression of Fas, FasL and Bcl-2 in the pathogenesis of autoimmune thyroid disorders

To investigate the expression of apoptosis-related protein (Fas, FasL, and Bcl-2) in the pathogenesis of autoimmune thyroid disorders (ATDs), immunohistochemical staining was performed on 20 Hashimoto‘s thyroiditis (HT), 20 Graves‘ disease (GD), and 20 thyroid follicular adenoma (TFA, as control). All the cases expressed Fas, mainly on the cell surface and cytoplasm. FasL was found in 17 cases of the TFA. Bcl-2 was detected in 15 cases of HT, 19 of GD and 17 of TFA. In T FA, a moderate Fas expression and a minimal or no FasL expression was detected on follicular cells. In HT, the follicles adjacent to infiltrating lymphocytes showed increased levels of Fas and FasL expression. A weaker staining of Fas and FasL was exhibited on infiltrating lymphocytes than on thyrocytes. In a comparison of GD with HT, thyrocytes and lymphocytes showed similar Fas staining, but for FasL the staining was rather weaker in HT. The expression of Bcl-2 was nearly identical in GD and TFA, but much weaker on the follicular cells in vicinity of lymphocytes and on the lymphocytes located in germinal centers of HT tissues. The expression of Fas, FasL, Bcl-2 in Hashimoto‘s thyroiditis and Graves‘ disease were almost same. FasL strong expression and Bcl-2 weak expression on the follicles in HT may induce apoptosis. These results provided evidence for expression of Fas, FasL and Bcl-2 in the pathogenesis of autoimmune thyroid disease. The lymphocytes seem not to be directly engaged in the process v/a their own FasL, but they may provide some cytokines that, in turn, upregulate Fas and/or FasL expression to induce apoptosis.     

Lack of linkage and association between autoimmune thyroid diseases and the CTLA-4 gene in a large Tunisian family.

The autoimmune thyroid diseases (AITDs) including Graves' disease and Hashimoto's thyroiditis are inherited as complex traits. We have performed linkage and association studies to investigate the role of CTLA-4 gene in the AITDs development using the D2S311, D2S143, the intragenic CTLA-4 (AT)(n) microsatellite markers and the CTLA-4 (A/G) dimorphism in exon 1. Four extended pedigrees belonging to a large Tunisian family named Akr and including 154 individuals from which 20 were affected with Hashimoto's thyroiditis and 26 with Graves' disease, were used in this investigation. No evidence for linkage with none of the markers was found under neither dominant nor recessive models [Z=-7.14 and Z=-14.32 at theta=0.0, respectively for the CTLA-4 (AT)(n) marker]. A family-based association study on 51 nuclear families derived from the Akr pedigree was performed by the FBAT approach applied to the CTLA-4 (AT)(n) marker and the CTLA-4 (A/G) dimorphism. We found no association of individual alleles to disease for both markers. These results showed no evidence for the involvement of the CTLA-4 locus in the AITDs pathogenesis.     

Autoantibodies to p53 in sera of patients with autoimmune thyroid disease

Mutations in the tumor suppressor gene, p53, lead to intracellular accumulation of abnormal p53 protein and are associated with p53 autoantibodies. p53 also accumulates in autoimmune diseases and Hashimoto's thyroiditis, but it is unknown if p53 autoantibodies occur in the latter. We measured p53 autoantibodies in the sera of 93 patients with thyroid disease and 19 patients without thyroid disease. Anti-p53 antibodies were detected in the sera from 4.2% (2/48) of patients with autoimmune thyroid disease, including one patient with Hashimoto's thyroiditis (3.7%, 1/27) and one with Graves' disease (4.8%, 1/21). A third patient with pseudohypoparathyroidism, but without thyroid disease, was also positive (1/19; 5.2%). None of 19 patients with differentiated thyroid cancer had anti-p53 antibodies. We conclude that anti-p53 antibodies can be detected in the sera from approximately 4% of patients with autoimmune thyroid disease. This finding suggests that increased DNA damage and apoptosis may be associated with autoimmune thyroid disease.     

Fas-FasL in Hashimoto's Thyroiditis

Hashimoto's thyroiditis is a common chronic autoimmune disease characterized by the loss of thyroid follicular cells (thyrocytes) that are gradually replaced by lymphocytic infiltration and diffuse fibrosis. These morphological findings suggested that autoreactive T-cell clones were responsible for thyrocyte destruction and hypothyroidism through effector–target cytotoxic recognition. Later, autonomous interaction between thyrocyte Fas and FasL has been proposed as a major mechanism of thyrocyte depletion in Hashimoto's thyroiditis. Here, we analyze the possible role of Fas and FasL in the pathogenesis of Hashimoto's thyroiditis. We suggest that the Fas–FasL system dictates the outcome of the autoimmune response by acting on both immune and target cells.     

Clinical value of a bispecific antibody binding to thyroglobulin and thyroperoxidase (TGPO-aAb) in various thyroid diseases.

TGPO-aAb is a bispecific antibody which binds to thyroglobulin as well as thyroid peroxidase. It is supposed to be raised in some patients with autoimmune thyroid disease. We investigated 205 patients suffering from Graves' disease (n = 81), Hashimoto's thyroiditis (n = 36), toxic nodular goitre (n = 50), differentiated carcinoma of the thyroid (n = 10), and autoimmune thyropathy of unknown origin (n = 28). An immunoradiometric assay was used to measure serum TGPO-aAb. Eighty-nine of 205 patients had elevated titres of TGPO-aAb. If TGPO-aAb were raised then autoantibodies against thyroglobulin and thyroid peroxidase were always raised, too. This was, however, not true vice versa. We found TGPO-aAb in 61% of patients with Hashimoto's, 49% of patients with Graves', 64% of patients with autoimmune thyropathy, but only in 12% of patients with toxic nodular goitre. In patients with thyroid carcinoma TGPO-aAb was found only if there was evidence of paraneoplastic autoimmune thyroiditis. We re-examined 16 of 36 patients with Hashimoto's thyroiditis after 1 year: 8 patients had retained their raised TGPO-aAb, 4 patients showed no TGPO-aAb on both occasions, and 4 patients had 'lost' their previously raised TGPO-aAb on follow-up. We conclude that TGPO-aAb may provide additional information in Hashimoto's thyroiditis. Determination of TGPO-aAb does not allow to distinguish between various forms of autoimmune thyroid disease. Nevertheless, the presence of TGPO-aAb and its variation during the natural course of autoimmune thyroid disease remains to be understood which would give a better insight into its clinical significance.     

Terminal complement complexes and C1/C1 inhibitor complexes in autoimmune thyroid disease.

The potential role of complement activation and the membrane attack complex in the pathogenesis of Graves' disease and Hashimoto's thyroiditis has been investigated by measuring serum concentrations of the C1r-C1s-C1 inhibitor complex (C1/C1-inh) and the terminal complement complex (TCC), and by studying the binding to thyroid tissue of monoclonal and polyclonal antibodies against TCC neoantigens. Serum C1/C1-inh and TCC concentrations were significantly increased in 29 patients with untreated Graves' disease compared with 47 healthy subjects (P less than 0.001 for both), and decreased significantly after carbimazole treatment in 18 of these patients for whom post-treatment samples were available (P less than 0.01 and P less than 0.02, respectively). The serum TCC concentration, but not that of C1/C1-inh, was also significantly increased in 15 patients with Hashimoto's thyroiditis compared with the 47 healthy subjects (P less than 0.001). TCCs were identified by immunohistochemical staining around the thyroid follicles in thyroidectomy specimens from patients with Graves' disease (six out of six) and Hashimoto's thyroiditis (two out of two); normal thyroid tissue from two subjects showed no staining. These results suggest a role for complement, in particular the membrane attack complex in the pathogenesis of autoimmune thyroid disease.     

Identification of apoptotic proteins in thyroid gland from patients with Graves' disease and Hashimoto's thyroiditis

Apoptosis, i.e. natural programmed cell death, is a physiological phenomenon indispensable for normal functioning of the organism. The signal to apoptosis can be started practically in any cell. Disturbances in the apoptosis regulation determine the essential link of the pathogenesis of many diseases, including autoimmune thyroid disorders. The aim of the study was to assess the expression of Fas/FasL and caspase eight in the tissues of the thyroid gland in patients with Graves' disease (GD), non-toxic nodular goiter (NTNG) and Hashimoto's thyroiditis (HT). The analysis of Fas/FasL expression was performed by western blot and immunohistochemical investigation with DAB-visualization and Mayer's hematoxylin staining. Caspase-8 expression in thyroid follicular cells was assayed by western blot method. Identification of the proapoptotic proteins FasL and Fas exhibited their pronounced expression in the thyroid tissue in GD patients (++; ++) and HT (+++; +++) as compared to the NTNG group (0/+; 0/+). Among the study groups, the expression of caspase-8 was revealed in band 55 kDa from patients with autoimmune thyroid diseases. In GD patients, the percentage of thyrocytes with FasL expression correlated positively with TRAb (R = 0.58, p < 0.02). However, no such correlations were noted in HT or non-toxic multinodular goiter. There were no significant correlations between thyroid hormones and the percentage of thyrocytes with Fas and FasL expression. In conclusion, our findings suggest that the changes in the expression of apoptotic molecules on the surface of T lymphocytes and thyroid follicular cells in patients with autoimmune thyroid disorders reflect their substantial involvement in the pathogenesis of GD and HT. In addition, analysis of Fas/FasL and caspase-8 expression in thyroid tissue may indicate the disease activity and immunological phenotype.     

Preferential use of T-cell receptor V genes in human autoimmune thyroid disease.

We review here our analyses of hTcR V gene activity within the thyroid glands of patients with autoimmune thyroid disease. Our data, based on thyroid aspiration specimens, indicate that early in the onset of Graves' disease there is a marked restriction in both hTcR V alpha and V beta gene families utilized by intrathyroidal T-cells. Later, however, and as seen in surgical thyroid specimens from patients with long term disease, there appears to be a loss of V beta restriction for unclear reasons. In contrast, patients with Hashimoto's thyroiditis are usually diagnosed later in the natural history of the disease and appear to show much less hTcR V gene family restriction. The mechanisms driving the use of few and many hTcR V genes within the thyroid gland are likely to be complex and may reveal important insights into disease pathogenesis.     

Long-term pathologic changes of alpha1-acid glycoprotein (orosomucoid) glycoforms in autoimmune thyroid disease

OBJECTIVE: We measured alpha1-acid-glycoprotein (AGP) in patients with autoimmune thyroid disease to study a possible relationship between microheterogeneity of the naturally occurring glycoforms of AGP and autoimmune thyroid disease. DESIGN, PATIENTS, MEASUREMENTS: In a group of 12 fasting thyrotoxic patients (11 females, mean age: 43 years) with newly diagnosed Graves' disease (subgroup 1), we measured serum concentrations of total AGP and its 3 glycoforms (micromol/l, crossed affinity immunoelectrophoresis with con A in the first dimension gel) as well as total thyroxine, total triiodothyronine, thyrotropine, thyroid peroxidase antibodies (anti-TPO), antibodies against the TSH receptor (TRAb, TRAK), at baseline and after 12 months of antithyroid drug therapy (ATD). For comparison, 4 subgroups of thyroid patients (patients with Graves' disease and thyroid associated ophthalmopathy (TAO) (subgroup 2, n = 10), radioiodine treated Graves' patients (subgroup 3, n = 7), Graves' patients without TAO (subgroup 4, n = 13), patients with Hashimoto's thyroiditis (subgroup 5, n = 8)) and 25 normal controls (17 females, mean age: 38 years) were studied. RESULTS: In subgroups of TRAb positive Graves patients' serum levels of glycoform 1, 2 or 3 increased significantly (p < 0.005) after 12 months of ATD as compared to both baseline of that person or normal controls. No significant changes were found in the TRAb negative Hashimoto subgroup. CONCLUSION: Patients with autoimmune Graves' disease changed their relationship to AGP, and thus a role of AGP and its 3 glycoforms is suggested in the pathogenesis of Graves' disease.     

Heterogeneity of thyroid autoantigens identified by immunoblotting

Autoimmune thyroid disease in man is commonly associated with autoantibodies against thyroglobulin, microsomes, and the TSH receptor, and the character and specificity of these antithyroid antibodies have been extensively utilized in investigating these conditions. In the present study we have asked whether other thyroid-related antigens exist, against which autoantibodies may be directed. A crude thyroid extract was separated by polyacrylamide gel electrophoresis followed by immunoblotting with serum obtained from patients with Graves' disease or Hashimoto's thyroiditis. Antibodies in sera from patients with Graves' disease and Hashimoto's thyroiditis reacted with many antigenic determinants in immunoblots of the thyroid membrane preparation (2000g supernatant). These determinants were disease specific in that sera from normals and patients with Addison's disease and rheumatoid arthritis did not react, but there was no difference between the patterns of reactivity with Graves' disease or Hashimoto's thyroiditis sera. Thyroglobulin produced two predominant bands of reactivity at 320 and 200 kDa, whereas purified microsomal antigen produced a triplet of bands around 105 kDa, when these preparations were reacted with appropriate autoimmune sera. Nonetheless, some sera produced additional bands with the microsomal antigen blots, indicating that some of the antigens which were detected using crude thyroid membrane remained in the microsome preparation to produce multiple antibody binding reactivities. We were unable to inhibit any of the antibody binding with TSH. Purification of individual thyroid antigens on the basis of their molecular weights should standardize current antibody assays and permit more detailed evaluation of the cellular immune responses in Graves' disease and Hashimoto's thyroiditis.     

The expression and role in T cell adhesion of LFA-3 and ICAM-2 on human thyroid cells.

Thyroid follicular cells from patients with Graves' disease and Hashimoto's thyroiditis express intercellular adhesion molecule-1 (ICAM-1) and this is in part responsible for T cell adherence in vitro. To assess the potential role of other adhesion molecules in autoimmune thyroiditis, we investigated the expression and function of lymphocyte function-associated antigen-3 (LFA-3) and ICAM-2 on thyroid cells. Under basal culture conditions, a mean of 22.7% of Graves' thyroid cells (n = 8) expressed LFA-3 and this was enhanced by a mixture of T cell-derived cytokines and by IL-1, but not by TSH. LFA-3 was also demonstrated on Graves' (n = 4) and Hashimoto (n = 2) thyroid cells by immunohistochemical staining ex vivo. A small number of thyroid cells (mean 5.5%, n = 5) expressed ICAM-2 by flow cytometry but this was not altered by cytokines, and ICAM-2 could only be demonstrated on endothelial cells by immunohistochemical staining. It seems likely that contamination of primary thyroid cultures by such cells accounted for the small number of ICAM-2+ cells found using flow cytometry. Almost all of the cultured cells expressing LFA-3 or ICAM-2 also expressed ICAM-1, as assessed by dual staining. Blocking LFA-1, LFA-3, and ICAM-1 with monoclonal antibodies inhibited the adherence of T cells to thyroid follicular cells in assays of cell clustering; antibodies against ICAM-2 had no effect. These results show that two important adhesion receptor ligands, ICAM-1 and LFA-3, are expressed by thyroid cells in autoimmune thyroiditis and that these are likely to have functional importance in allowing T cells to bind to thyroid cell targets. This may play an important role in the initiation and maintenance of Graves' disease and Hashimoto's thyroiditis.     

Analysis of immunoglobulin VH and TCR cbeta polymorphisms in a large family with thyroid autoimmune disorder

In order to investigate the association of TCR Cbeta and immunoglobulin (Ig) VH polymorphisms with thyroid autoimmune diseases (TAD), we analyzed restriction-endonuclease-generated polymorphisms using T-cell receptor (TCR) Cbeta and VH gene-family-specific probes. We tested genomic DNAs of patients isolated from a large family affected with Graves' disease and Hashimoto's thyroiditis as well as the genomic DNA of unrelated Tunisian controls. Hybridization of BglII-digested DNA with a TCR Cbeta probe revealed two alleles of 9.2 and 10 kb. These Cbeta polymorphisms have already been found in the Caucasian population. However, there was no abnormal distribution of this polymorphism in patients with TAD, compared to related healthy individuals and to unrelated Tunisian controls. Besides, there was a low VH polymorphism in members of the family affected with TAD. Analysis of the Ig gene families revealed no restriction site polymorphism pattern specific for TAD. Copyright Copyright 1999 S. Karger AG, Basel     

The CD40, CTLA-4, thyroglobulin, TSH receptor, and PTPN22 gene quintet and its contribution to thyroid autoimmunity: back to the future

Autoimmune thyroid diseases (AITD) are common autoimmune diseases, affecting up to 5% of the general population. Thyroid-directed autoimmunity is manifested in two classical autoimmune conditions, Hashimoto's thyroiditis, resulting in hypothyroidism and Graves' disease resulting in hyperthyroidism. Autoimmune thyroid diseases arise due to an interplay between environmental and genetic factors. In the past decade significant progress has been made in our understanding of the genetic contribution to the etiology of AITD. Indeed, several AITD susceptibility genes have been identified. Some of these susceptibility genes are specific to either Graves' disease or Hashimoto's thyroiditis, while others confer susceptibility to both conditions. Both immunoregulatory genes and thyroid specific genes contribute to the pathogenesis of AITD. The time is now ripe to examine the mechanistic basis for the contribution of genetic factors to the etiology of AITD. In this review, we will focus on the contribution of non-MHC II genes.     

The effects of HLA class II genes on the susceptibility to autoimmune thyroid diseases

Immunogenetic factors such as HLA, C4, T cell receptor and immunoglobulin allotypes were investigated in 115 Japanese patients with Graves' disease. The patients showed strong positive association with HLA-A2 (R.R. = 3.45, chi 2 = 14.93, Pc less than 0.002), Bw46 (R.R. = 6.47, chi 2 = 16.25, Pc less than 0.002), Cw11 (R.R. = 4.47, chi 2 = 9.19, Pc less than 0.04) and DRw8 (R.R. = 2.22, chi 2 = 5.62, P less than 0.03, Pc: n.s.) which form one of the typical HLA haplotypes in Japanese population due to the strong linkage disequilibria. On the other hand, the patients showed negative association with HLA-B7 (R.R. = 0.15, chi 2 = 7.15), Bw52 (R.R. = 0.24, chi 2 = 7.86), DR1 (R.R. = 0.07, chi 2 = 9.71) and DQw1 (R.R. = 0.45, chi 2 = 5.62), which form HLA-B7-DR1-DQw1 and Bw52-DR2-DQw1 haplotypes. Because HLA-A2 -Bw46-Cw11-DR9 haplotype was reported to be associated with Chinese Graves' patients, and because Bw46 showed the strongest association with the Japanese patients, it was suggested that HLA class 1 antigen, Bw46, might be the primary immunogenetic factor involved in the pathogenesis of Graves' disease. Since HLA-DQw6 was reported to be associated negatively with Hashimoto's thyroiditis as same as the current observation in Graves' disease, it was suggested that HLA-DQw6 may determine the resistance to autoimmune thyroiditis. The effect of HLA-DQw6 gene, therefore, on the experimental autoimmune murine thyroiditis (EAMT) was examined, using DQw6-transgenic mouse. F1 with C3H mouse, and backcross progeny between the F1 and C3H mouse which is a susceptible strain to EAMT. The measurement of anti-thyroglobulin antibody indicated that C3H mouse, (C3H x DQ-B6) F1 and backcross progeny between the F1 and C3H were high responders to the thyroglobulin, but that B6 mouse and DQ-B6 mouse were low responders. The histological examination of the thyroid gland of these mice failed to demonstrate the significant difference in susceptibility to EAMT among these mice. These results suggested that the immune response to the thyroglobulin was controlled by H-2k haplotype and that the effect of HLA-DQw6 gene on the immune response to thyroglobulin and on the autoimmune thyroiditis was marginal.     

Expression of intercellular adhesion molecule-1 (ICAM-1) on thyroid epithelial cells in Hashimoto's thyroiditis but not in Graves' disease or papillary thyroid cancer.

In order to study the possible role of antigen-independent adhesion systems in thyroid autoimmunity, we evaluated by indirect immunofluorescence the expression of lymphocyte functional antigen-1 (LFA-1) and its ligand ICAM-1 on mononuclear cell infiltrates (when present) and thyroid follicular cells of four patients with Hashimoto's thyroiditis, 30 with Graves' disease, five with papillary cancer, two with follicular adenoma, and two normal thyroid specimens. The expression of MHC class I and class II antigens was also evaluated. Most mononuclear infiltrates were LFA-1 positive, as expected. A positivity for ICAM-1 on follicular cells was observed in three out of four Hashimoto's thyroiditis specimens; such a phenomenon was totally absent in Graves' disease or any other pathological condition, or in normal tissue. MHC class II expression on thyrocytes was observed in all the patients with Hashimoto's thyroiditis, in 27 out of 30 with Graves' disease and in three out of five papillary cancer specimens.     

Analysis of MHC genes in a Tunisian isolate with autoimmune thyroid diseases: implication of TNF -308 gene polymorphism

Autoimmune thyroid diseases (AITDs), which include Hashimoto thyroiditis (HT), Graves' disease (GD) and primary idiopathic myxoedema (PIM), are recognized as multifactorial diseases. In this study, we have examined single and haplotypic genetic variation across the major histocompatibility complex (MHC) in a Tunisian isolate with a high prevalence of AITDs (62 patients: 32 with GD, 9 with HT and 21 with PIM). Genotyping was performed for HLA class I and II alleles as well as polymorphisms within tumor necrosis factor (TNF), lymphotoxin alpha (TLalpha) and heat shock protein (HSP70-02 and HSP70-hom) genes. Our results showed association of HLA-A2-B50-TNF 2 haplotype with AITDs (p = 0.045). Linkage analysis using Simwalk2 program has shown significant result with TNF -308 gene polymorphism (p = 0.03). The FBAT has given evidence for genetic association with TNF -308 and HLA-DR gene polymorphisms. TNF 2 allele was associated with GD (p = 0.0011), whereas TNF 1, HLA-DR11 and DR12 (p = 0.0039, p = 0.00089 and p = 0.0056, respectively) were rather implicated in HT pathogenesis. Results found by TDT-STDT have confirmed the involvement of the TNF -308 gene polymorphism in AITD pathogenesis (p < 10(-9)).     

Autoantibodies highly increased in patients with thyroid dysfunction

To evaluate the significance of antithyroid antibodie levels, five hundred and twenty-six patients with thyroid diseases and 292 health subjects from Yuci district, Shanxi province, China, were studied. Serum levels were determined for thyroid hormone receptor antibody （TRAb）, microsomal antibody （TMAb） and thyroglobulin antibody （TGAb）. Among patients, the percentages for nodular goiter and thyroid adenoma, Graves＇ disease, and Hashimoto＇s thyroiditis are 44.1%, 19.6% and 17.7%, respectively. The ratios of female to male were 2.0 to 15.6. Antibody-positive patients for TMAb, TGAb and TRAb were detectable as 94.6%, 76.3% and 20.4% for Hashimoto＇s thyroiditis, and 40.0%, 30.0% and 90.3% for Graves＇s disease. In conclusion, the high levels of the TRAb in Graves＇ disease, and those of the TGAbFFMAb in Hashimoto＇s thyroiditis and idiopathic hypothyroidism are meaningful for characterizing the epidemiological basis of the diseases and for using as prognostic indicators for the relapse in individual patients. Cellular ＆ Molecular Immunology.     

Detection of interleukin-6 and interleukin-1 production in human thyroid epithelial cells by non-radioactive in situ hybridization and immunohistochemical methods.

Human endocrine thyroid epithelial cells have been described to produce cytokines in vitro. In order to determine whether they do so in vivo during thyroiditis, parallel studies on mRNA expression with a non-radioactive in situ hybridization technique and immunohistochemical detection for the protein were performed on frozen sections of thyroid samples from autoimmune thyroiditis (Graves' disease and Hashimoto's thyroiditis), non-toxic goitre and normal thyroid tissue. cDNA probes were sulphonated and their hybridization with mRNA was detected with a sulphonyl-specific monoclonal antibody. This signal was amplified and visualized with the alkaline phosphatase-anti-alkaline phosphatase (APAAP) system. The protein products were detected with immuno-purified rabbit F(ab')2 antibody fragments recognizing recombinant human cytokines, visualized by the immunoperoxidase technique. Each sample was studied at the two levels. Both interleukin-6 mRNA and protein were found in the endocrine cells. There was no obvious difference between autoimmune thyroiditis and non-toxic goitre. However, normal thyroid epithelial cells produced less interleukin-6. Interleukin-1 alpha mRNA and its protein were found in epithelial cells from Hashimoto's thyroiditis samples, but not in the others, except one Graves' disease sample, in which only mRNA was detected. Interleukin-1 beta was not detected in these cells, its mRNA was only found in one of the Graves' disease samples. These cytokines were also detected in some infiltrating cells.