Organ-specific autoimmune diseases and cytokines]

Changes in serum levels of cytokines in organ-specific autoimmune diseases were reviewed. Serum levels of IL-12, critical for the development of Th1 cells, were increased in thyrotoxic patients with Hashimoto's thyroiditis and Graves' disease. Serum levels of IL-5, secreted from Th2 cells, were increased in thyrotoxic patients with Graves' disease, but not in thyrotoxic patients with Hashimoto's thyroiditis. In patients with IDDM, serum levels of Th1 cytokines (IFN-gamma and IL-2) were increased but serum levels of Th2 cytokines (IL-4 and IL-10) were not increased. These findings suggest that measuring the serum concentration of various cytokines is useful to analyze Th1/Th2 balance in autoimmune diseases.     

Anti-CD38 autoimmunity in patients with chronic autoimmune thyroiditis or Graves' disease.

Autoantibodies directed against human CD38 (an enzyme catalysing the interconversion of NAD(+) and cyclic ADP-ribose) have been demonstrated recently in patients with type 2 diabetes. We tested 220 consecutive Caucasian patients with autoimmune chronic thyroiditis, 104 patients with Graves' disease, 220 subjects from the general population (control I) and 78 healthy control subjects not affected by thyroid autoimmune disorders (control II) for the presence of anti-CD38 autoimmunity. Using Western blot analysis and optical densitometry, a specific band corresponding to human recombinant CD38 was identified in the serum of several subjects. By defining anti-CD38 positivity as a standardized optical reading > 3 s.d. higher than the mean value of control I, 10.4% of patients with thyroiditis and 7.7% of Graves' patients were anti-CD38 positive (P = 0.0009 versus 1.8% of control I). Similarly, 13.1% of patients with thyroiditis and 10.5% of Graves' patients had a standardized optical reading > 3 s.d. higher than the mean value of the subjects not affected by thyroid autoimmune disorders (P = 0.002 versus 1.2% of control II). Anti-CD38 autoimmunity did not differ between euthyroid, hyperthyroid or hypothyroid patients or between patients with or without thyroid hypoechogenicity. Anti-CD38 autoantibodies were associated with higher levels of circulating antithyroid-peroxidase antibodies (P = 0.03) and they were more frequent in Graves' patients with ophthalmopathy (P < 0.05). Anti-CD38 autoantibodies are a new autoimmune marker in chronic autoimmune thyroiditis and Graves' disease. The specific role of CD38 and its autoantibodies in the modulation of thyroid cell function or growth remains to be investigated.     

Expression and function of multiple regulators of complement activation in autoimmune thyroid disease.

Membrane attack complexes of complement occur around thyroid follicles in Graves' disease and Hashimoto's thyroiditis. The lytic potential of such complexes is controlled by membrane-bound and fluid phase regulators and we have investigated the role of these in autoimmune thyroid disease. By immunohistochemical staining, clusterin and S-protein were found in all nine thyroid specimens from patients with Graves' disease and S-protein was found in one of two Hashimoto glands. CD46, CD55 and CD59 were found on thyroid cells in all specimens. CD46 and CD55 expression occurred on thyroid cells cultured in vitro and was increased significantly by culture with interleukin-1 (IL-1) and interferon-gamma (IFN-gamma), which are known to be released by the lymphocytic infiltrate in these conditions. Blocking CD55 had a weak and inconsistent effect on complement-mediated thyroid cell killing in vitro but, in four of five experiments, blocking CD46 enhanced killing. However, the effect of blocking CD59 was greater in all cases than blocking CD46 or CD55. Expression of these fluid phase and membrane-bound proteins may be important in determining the severity of thyroid damage produced by complement fixation in Graves' disease and Hashimoto's thyroiditis.     

The effects of CD40- and interleukin (IL-4)-activated CD23+ cells on the production of IL-10 by mononuclear cells in Graves' disease: the role of CD8+ cells

The possible roles of CD8+ cells in the abnormal T cell-dependent B-cell activation in Graves' disease were investigated by analysing lymphocyte subsets in peripheral blood mononuclear cells (PBMC) and their production of soluble factors and cytokines such as IL-10 in patients with Graves' disease, Hashimoto's thyroiditis and normal controls. The PBMC were separated into CD8+ and CD8-depleted cells by magnetic separation columns, and cultured for 7 days with or without anti-CD40 monoclonal antibodies and IL-4. The culture supernatant was assayed for sCD23 and IL-10 using EIA, and the remaining cells were analysed by flow cytometry. Stimulation with anti-CD40 antibody together with IL-4 increased sCD23 levels and the number of CD23+ cells. The latter was further augmented by depletion of CD8+ cells. This combination of B cell stimulants increased production of IL-10 by PBMC from patients with Graves' disease. The CD40- and IL-4-activated production of IL-10 was decreased by CD8+ cell depletion. In contrast, constitutive production of IL-10 was increased after CD8+ cell depletion in a group of patients with low basal secretion levels (<35 ng/ml). It was, however, decreased in a group with higher basal production levels, but such a relationship was not found in the normal control group. Thus, T cell-dependent B-cell activation via a CD40 pathway activates CD23+ cells, leading to over-production of IL-10 and a shift of the Th1/Th2 balance to Th2 dominance, while CD8+ cells may suppress this activation to counteract the Th2 deviation in Graves' disease.     

Increase in peripheral natural killer cell activity in patients with autoimmune thyroid disease.

Changes in the activity and number of natural killer (NK) cells in peripheral blood in patients with autoimmune thyroid disease were examined. NK activity was measured in a 4-hr 51Cr-release assay and the number of NK cells was analyzed with FITC-conjugated monoclonal antibodies by use of an automated flow cytometer. NK activity in patients with untreated Graves' disease (n = 25, 39.7 +/- 13.5%, P less than 0.05) and Hashimoto's thyroiditis (n = 18, 41.0 +/- 14.2%, P less than 0.05) was high compared to the activity in non-pregnant controls (n = 61, 32.6 +/- 15.0%). NK activity in patients with postpartum Graves' thyrotoxicosis (n = 11, 48.6 +/- 18.9%) was markedly increased compared to the activity in non-pregnant controls (P less than 0.01) and in postpartum controls (n = 29, 33.8 +/- 15.2%, P less than 0.05), although the mean ages of each group did not differ significantly. Moreover, NK activities in the thyrotoxic state were significantly higher than those in the euthyroid state in the same patients with postpartum Graves' thyrotoxicosis or with postpartum destructive thyrotoxicosis. The number of CD16 positive cells increased in patients with postpartum Graves' thyrotoxicosis. However the number of CD16 and CD57 positive cells were normal in all other groups of patients. These results indicate that an increase of NK activity is associated with exacerbation of autoimmune thyroid disease both in Hashimoto's thyroiditis and in Graves' disease and suggest that NK cells might have an important role for the control of disease activity in autoimmune thyroid disease.     

Soluble intercellular adhesion molecule-1 (sICAM-1) in sera of patients with Graves' ophthalmopathy and thyroid diseases.

Intercellular adhesion molecule, a ligand for the leucocyte integrins CD11a/CD18 (LFA-1) and CD11b/CD18 (Mac-1), that plays an important role in a variety of inflammatory and immune-mediated mechanisms, is strongly expressed in retroocular connective tissue from patients with Graves' ophthalmopathy (GO) and involved in lymphocyte attachment to cultured retroocular fibroblasts via the ICAM-1/LFA-1-mediated pathway. Here, we report the detection and functional activity of a soluble form of the ICAM-1 molecule (sICAM-1) in sera from patients with GO and other thyroid diseases. Serum concentrations for sICAM-1 were determined using a highly sensitive ELISA. Compared with normal controls, patients with hyperthyroid or euthyroid GO and patients with Riedel's invasive fibrous thyroiditis revealed markedly elevated sICAM-1 serum concentrations (all P < 0.0001). In patients with Graves' disease (GD) without clinical GO and in patients with Hashimoto's thyroiditis (HT), sICAM-1 levels were elevated to a lesser degree (both P < 0.001). sICAM-1 serum levels in patients with non-autoimmune hyperthyroidism due to a toxic adenoma were not significantly different from normal controls. In a separate group of 12 patients with severe inflammatory GO, sICAM-1 serum levels markedly declined (P < 0.0001) within 3 months of glucocorticoid therapy in nine patients who responded to this form of treatment with a decrease in periorbital inflammation. In contrast, sICAM-1 serum levels remained unchanged in three patients with poor response to steroids and persistent inflammatory periorbital disease. When tested in a cell adhesion assay, GO sera containing elevated concentrations of sICAM-1 were found to enhance the attachment of peripheral blood mononuclear cells (PBMC) to interferon-gamma (IFN-gamma)-treated retroocular fibroblasts in a dose-dependent manner, up to a maximal stimulation of approximately 5.5-fold (P < 0.001). This effect was abolished by preabsorption of sera with a MoAb against ICAM-1 and inhibited, in a dose-dependent manner, by coincubation with increasing concentrations of purified sICAM-1. In conclusion, sICAM-1 concentrations are markedly elevated in sera from patients with GO, and changes in sICAM-1 serum levels during glucocorticoid therapy closely parallel changes in the degree of inflammation. Given the capacity of sICAM-1 to modulate the adhesion of lymphocytes to retroocular fibroblasts in vitro, sICAM-1 may play a role in the ongoing immune process within the connective tissue in GO.     

Decreases in alpha beta T cell receptor negative T cells and CD8 cells, and an increase in CD4+ CD8+ cells in active Hashimoto''s disease and subacute thyroiditis.

We examined peripheral lymphocyte subsets in patients with autoimmune thyroid disease, or subacute thyroiditis, in the active stage when possible. During destructive thyrotoxicosis arising from alpha beta T cell receptor (TCR) negative T (WT31-CD3+) cells and CD8 (CD4-CD8+) cells decreased and those of CD4+CD8+ cells increased slightly, resulting in proportional increases in CD4 (CD4+CD8-) cells, non-T, non-B (CD5-CD19-) cells, and the CD4/CD8 cell ratio. Changes were similar in active subacute thyroiditis. During stimulative thyrotoxicosis in active Graves' disease, the numbers of such T lymphocyte subsets were not changed, but only the number of CD5+ B (CD5+CD19+) cells increased markedly, resulting in proportional decreases in total T (CD3+) cells, alpha beta+ TCR T (WT31+CD3+) cells, CD8 cells, and non-T, non-B cells. A serial study of some of the patients showed opposite changes in alpha beta TCR- T cells, the CD4/CD8 cell ratio, and CD5+ B cells between the active stages of Graves' and Hashimoto's diseases. alpha beta TCR- T cells were mostly gamma delta TCR+ T (IIF2+ CD3+) cells in these patients. These data suggest that alpha beta TCR-T (gamma delta TCR+ T), CD8, and CD4+ CD8+ cells are important in thyroid destruction in Hashimoto's disease and subacute thyroiditis, and that CD5+ B cells are important in thyroid stimulation in Graves' disease.     

Marked increase of CD5 + B cells in hyperthyroid Graves' disease

We examined the proportions of B lymphocytes bearing CD5 cell surface antigen (CD5+ B cells), which are capable of making autoantibodies, in peripheral blood from patients with various thyroid diseases. The level of CD5+ B cells was markedly increased (>9.0%) above the normal range (0.5-7.7%) in untreated, hyperthyroid patients with Graves' disease, although about 10% of the patients had no detectable serum thyroid-stimulating hormone (TSH) receptor antibody (TRAb). However, the levels of CD5+ B cells were normal in untreated patients with destructive thyrotoxicosis due to aggravation of Hashimoto's thyroiditis or subacute thyroiditis. In patients with stimulated hyperthyroid Graves' disease the levels of CD5+ B cells were correlated with those of thyroid hormones and TRAb, all significantly increased. However, once hyperthyroidism was controlled by anti-thyroid drugs, CD5+ B cells were decreased, followed in turn by reduction of TRAb. We conclude that the proportion of CD5+ B cells is useful as a therapeutic index and for diagnosis of Graves' disease and its differentiation from destruction-induced thyrotoxicosis.     

The production and characterization of thyroid-derived T-cell lines in Graves' disease and Hashimoto's thyroiditis

Although the thyroid gland itself is a major site of the autoimmune response, the study of T-cell function in autoimmune thyroid disease has usually relied on peripheral blood as a source of cells. In this study, we have established thyroid-derived T-cell lines from six patients with Graves' disease and one patient with Hashimoto's thyroiditis by culturing the thyroid lymphocytes on an autologous thyroid follicular cell monolayer in the presence of exogenous interleukin 2 (IL-2). These T-cell lines have allowed in vitro investigation of thyroid-derived T-cell function, an approach which was previously limited by the number of lymphocytes obtained from the gland. The lines were predominantly OKT3, OKT4, and HLA-DR positive but showed heterogeneous proliferative responses. Some lines gave autologous or allogeneic mixed lymphocyte reactions but other did not. Only one of the seven lines responded well to the thyroid antigens thyroglobulin and microsomes presented by autologous monocytes. However, six of the lines proliferated in the presence of live but not dead autologous thyroid follicular cells, particularly when interferon-gamma (IFN-gamma) was added. This treatment has been shown to enhance HLA-DR and -DQ antigen expression by thyroid follicular cells in vitro. Furthermore, the proliferation induced by IFN-gamma-treated thyroid follicular cells was increased when thyroglobulin was also added. Together these results support the hypothesis that the expression of Ia antigens such as HLA-DR by thyroid follicular cells in autoimmune thyroid disease may be important in enhancing the autoimmune response, conferring on these cells the ability to present thyroid autoantigens to T cells. The use of thyroid-derived T-cell lines should permit a more detailed evaluation of the disordered immuno-regulation in Graves' disease and Hashimoto's thyroiditis than has been possible previously.     

Production of interleukin (IL)-5 and IL-10 accompanies T helper cell type 1 (Th1) cytokine responses to a major thyroid self-antigen, thyroglobulin, in health and autoimmune thyroid disease

Tumour necrosis factor (TNF)-alpha and interferon (IFN)-gamma exert detrimental effects in organ-specific autoimmune disease, while both destructive and protective roles have been demonstrated for interleukin (IL)-10, IL-4 and IL-5. We examined the production of these cytokines by peripheral blood mononuclear cells (PBMC) from patients with Hashimoto's thyroiditis (HT), Graves' disease (GD) and healthy controls, upon exposure to a thyroid self-antigen, human thyroglobulin (Tg), in the presence of autologous serum. Initially, TNF-alpha and IL-2 were produced in all three groups, accompanied by IL-10. Release of IFN-gamma, IL-4 and, notably, IL-5 ensued. Both patient groups exhibited increased TNF-alpha, IL-2, IFN-gamma and IL-10 responses, and PBMC from HT patients secreted lower amounts of IL-5 than male, but not female, controls. Enhanced TNF-alpha production by HT cells also occurred in the presence of pooled normal sera, indicating a dependency on intrinsic cellular factors. Conversely, higher production of TNF-alpha and IL-5 occurred in the presence of autologous sera than in the presence of pooled normal sera in both patient groups, indicating a dependency on serum constituents. Complement appeared to promote the production of IL-2 and particularly IL-5, the levels of which were reduced by neutralization of complement by heat- or zymosan treatment. The production of IFN-gamma and IL-2 of the three groups together correlated directly with the serum anti-Tg activity. Moreover, TNF-alpha, IFN-gamma, IL-5 and IL-10 responses were markedly inhibited by partial denaturation of Tg by boiling. We hypothesize that autoantibodies and complement may promote mixed Th1/Th2 cell cytokine responses by enhancing the uptake of autoantigens by antigen-presenting cells.     

Peripheral blood and intrathyroidal T cell clones from patients with thyroid autoimmune diseases

For a better understanding of the pathogenesis of thyroid autoimmune diseases, we have studied morphological and functional properties of T clones from peripheral blood lymphocytes (PBL) and from intrathyroidal lymphocytes (ITL) obtained from 3 patients with Graves' disease or 1 Hashimoto's thyroiditis. Investigations were carried out on clones cultured alone or cocultured with autologous thyrocytes. Clonage efficiency ranged from 30% to 33% for PBL and 10% to 36% for ITL. A predominance of CD4-positive clones was observed whatever the origin of the lymphocytes or the autoimmune pathology. Gamma interferon (IFN-gamma) was detected in the majority (17/19) of the clones tested. Intracytoplasmic interleukin (IL-4) was secreted in 7/19 clones and both cytokines were produced in 5/19 clones. In coculture a proliferative response and tumour necrosis factor (TNF-alpha) production were observed with 6 clones (4 from Graves thyrocytes and 2 from thyroiditis). No cytotoxic clone was derived from Graves or thyroiditis tissues. These data demonstrate that the large majority of T clones are principally CD4-T cells; all the clones secreted TNF-alpha and a large majority produced IFN-gamma. Only a few clones produced IL-4 alone or associated with IFN-gamma. Six T clones induced proliferative response and of TNF-alpha secretion in coculture. Further investigations must be performed on these antigen-reactive T clones to analyse their role in the pathogenesis of the human thyroid autoimmune diseases.     

自身免疫甲状腺病患者血清中IL-12和IL-18水平的分析

目的:提供自身免疫甲状腺病(AITD)患者体内Th1/Th2平衡紊乱的依据。方法:应用酶联免疫吸附法(ELISA)测定27例Graves病(GD)、24例甲状腺功能正常的桥本甲状腺炎(HT)、25例甲状腺功能低下的HT患者及20例正常对照者血清中IL12和IL18的浓度,并检测GD患者的甲状腺刺激性抗体。结果:GD患者与甲状腺功能正常的HT患者血中IL12、IL18水平无明显差异,但均高于正常对照者的相应水平。甲状腺功能低下的HT患者血中IL12和IL18的水平与正常对照者无差异。在GD和甲功正常的HT,IL18与IL12呈明显正相关。在GD,IL12和IL18均与其甲状腺刺激性抗体(TSAb)活性呈正相关。在甲状腺功能正常的HT还存在IL12和IL18二者与甲状腺球蛋白抗体(TgAb)的显著性正相关。结论:提示Th1型细胞在GD和HT两种AITD的发病中均起重要作用。通过抑制Th2型免疫反应,促进向Th1型的转变来治疗GD时,有可能导致病情恶化。     

Intrathyroidal accumulation of T cell phenotypes in autoimmune thyroid disease.

In this study we have correlated peripheral T cell subset phenotypes with intrathyroidal lymphocyte accumulation in patients with autoimmune thyroid disease (Graves' and Hashimoto's disease). Our study utilized euthyroid family members for one of our control groups (n = 48) thus significantly limiting familial, but not disease-specific, influences on these T cell phenotypes. Our principal new observations were found only in patients with Graves' disease. As previously reported, there was a decrease in CD8+ (suppressor/cytotoxic) T cells in the peripheral blood of patients with untreated hyperthyroid Graves' disease (n = 27) (mean +/- SEM, 19 +/- 1.1% in patients compared with 25 +/- 1.2% in controls, p = 0.03), a finding not observed in treated, euthyroid Graves' disease patients or their relatives. However, the relative number of CD8+ T cells, assessed by CD4:CD8 ratios, was increased in the intrathyroidal T cell populations (n = 10), when compared to normal and patient peripheral blood. There were no consistent changes in total CD4+ (helper) T cells in the peripheral blood of patients with treated and untreated Graves' disease but a reduction in CD4+2H4+ (suppressor-inducer) T cells was seen in patients undergoing surgery for Graves' disease (13 +/- 6.9% compared with 39 +/- 3.4%). Again, however, this T cell subset was increased within the target organ of the same patients (41 +/- 5.9%). These data point to either a selective accumulation, or a specific "homing", of certain T cell subsets within the thyroid gland of patients with Graves' disease where T cell differentiation may be strongly influenced by antithyroid drug treatment and the local immune environment.     

CD4+ T-cell clones from autoimmune thyroid tissue cannot be classified according to their lymphokine production

In order to define whether CD4+ T cells from autoimmune and non-autoimmune thyroid tissue could be classified according to their mediator production, lymphokine production was studied in 63 thyroid-derived CD4+ T-cell clones from four patients with Graves' disease, one with Hashimoto's thyroiditis, and one with non-toxic goitre (9-12 clones per patient). The production of interleukin 2 (IL-2), gamma interferon (IFN-gamma), tumour necrosis factor alpha (TNF-alpha), lymphotoxin (LT), interleukin 6 (IL-6) and transforming growth factor beta (TGF-beta) was assessed at the mRNA level by slot-blot analysis in unstimulated clones as well as after activation with monoclonal anti-CD3 (OKT3) and IL-2. No lymphokine production was found in unstimulated clones, whereas 56% of the clones produced all six lymphokines simultaneously after stimulation. In the remaining 44% usually not more than one lymphokine was missing from the complete panel. Lymphokine mRNA concentrations varied between different clones and different patients, but, in this small sample, not between the diseases from which the clones were originated. There was a significant correlation between IL-6, LT, and IL-2 mRNA levels and T-cell helper function, which was estimated by the stimulation of thyroid microsomal autoantibody production using autologous peripheral B cells. TGF-beta and IFN-gamma mRNA expression was unrelated to T-cell help. The results demonstrate that intrathyroid T cells from autoimmune and non-autoimmune thyroid disorders cannot be classified according to their lymphokine production, unlike some results with in vitro-induced mouse T-cell clones, where two populations, Th1 and Th2, have been described. Single T cells are capable of producing a whole panel of lymphokines and thus are capable of triggering a multitude of different processes.     

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.     

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.     

A general autoimmunity gene (PTPN22) is not associated with inflammatory bowel disease in a British population

A single-nucleotide polymorphism (C1858T) causing an amino acid substitution (R620W) in the lymphoid protein tyrosine phosphatase gene PTPN22 has been implicated in type 1 diabetes, rheumatoid arthritis, systemic lupus erythematosus, Graves' disease, juvenile idiopathic arthritis and Hashimoto's thyroiditis, thus revealing a general role for this gene in autoimmune disease. We investigated the association of the C1858T variant in an additional autoimmune disease population by performing a case-control study of 514 British individuals with inflammatory bowel disease (IBD) [294 with Crohn's disease (CD) and 220 with ulcerative colitis (UC)] and 374 normal controls. No significant differences in genotype or allele frequencies were observed between IBD, CD or UC and controls, indicating that PTPN22 does not influence risk of IBD.     

Detection of in vivo production of tumour necrosis factor-alpha by human thyroid epithelial cells.

We have established previously that human thyroid epithelial cells (TEC) from patients with autoimmune thyroiditis are able to synthesize cytokines, such as interleukin-1 (IL-1) and interleukin-6 (IL-6). This paper examines TEC in sections from autoimmune thyroiditis for the in vivo production of tumour necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma) using the combined techniques of in situ hybridization and immunohistochemistry. Thyroid tissue from patients with Graves' disease, Hashimoto's disease and non-toxic goitre was examined and both mRNA and the protein of TNF-alpha were detected in TEC on frozen sections. Representative figures of only Graves' samples are illustrated in this paper. In contrast, using the same methods, IFN-gamma was detected only in the infiltrating cells and not in TEC of thyroid tissue from the patients.     

Antibodies that promote thyroid growth. A distinct population of thyroid-stimulating autoantibodies

We used a strain of differentiated rat-thyroid cells in continuous culture (the FRTL-5 strain) to detect the presence of growth-promoting antibodies in serum samples from patients with autoimmune thyroid disease. We found that IgG preparations from 17 of 20 patients (85 per cent) with active Graves' disease and two of five patients (40 per cent) with Hashimoto's thyroiditis could augment thyroid-cell growth. In parallel with IgG-induced elevations in intracellular cyclic AMP levels in the same cell line, all 20 of the patients with active Graves' disease had thyroid-stimulatory antibodies. Patients' IgG preparations fell into three subclasses: those with both potent cyclic AMP stimulation and potent growth-promoting activity; those with potent cyclic AMP stimulation but low-level growth promotion; and those with potent growth promotion and low-level cyclic AMP action. Growth-promoting antibodies were not detected in patients with Graves' disease in remission (seven patients), nodular goiter (seven), subacute thyroiditis (five), or atrophic thyroiditis (one). Simultaneous assays of growth promotion and cyclic AMP stimulation may be useful in the care of patients with autoimmune thyroid disease.     

Characterization of the natural killer cell activity in Hashimoto's and Graves' diseases

Natural killer (NK) cell activity and blood mononuclear cell subpopulations were characterized in patients with Hashimoto's thyroiditis ( n = 11), Graves' disease ( n = 20), non-toxic goitre ( n = 10) and in normal controls ( n = 22). NK cell activity against K 562 target cells and the capability of IFN-α, Il-2, and indomethacin to enhance NK cell activity in vitro did not differ significantly between the groups. The percentages of large granular lymphocytes, CD5 +, CD4 +, CD8 + and CD16 + cells were normal in patients with non-toxic goitre, Hashimoto's and Graves' diseases. There was no correlation between NK cell activities and TgAb, MAb and TSAb. Although NK cell activity is suppressed in several autoimmune diseases, NK cell function is normal in patients with autoimmune thyroid disorders.