Expression of the costimulatory molecule B7/BB1 in autoimmune thyroid disease.

Efficient antigen presentation requires the provision of a costimulatory signal, the best characterized of which is B7/BB1. It is unclear whether thyroid cells expressing class II molecules can present autoantigens to T cells, although this has been suggested as an important mechanism in the initiation of Graves' disease and Hashimoto's thyroiditis. We have found that thyroid cells from patients with thyroid autoimmunity do not express B7/BB1 in vivo or in vitro, even after activation with the cytokines interleukin-1 or gamma-interferon, or with a phorbol ester.

Stimulation of extraocular muscle fibroblasts by cytokines and hypoxia: possible role in thyroid-associated ophthalmopathy.

Objective: Smoking is a risk factor for the development of thyroid-associated ophthalmopathy, an inflammatory process primarily affecting the fibroblasts in extraocular muscles. We wished to determine whether the extraocular muscle fibroblasts are more sensitive than dermal fibroblasts to T-cell derived cytokines, as a reason for this anatomical localization, and whether hypoxia alters fibroblast function, as one explanation for the susceptibility conferred by smoking.

Design: Fibroblasts derived from the skin or extraocular muscles of healthy subjects were cultured with cytokines under normal (5% CO2:95% air) and hypoxic (5% CO2:95% N2) conditions.

Production of bioactive and immunoreactive interleukin-6 (IL-6) and expression of IL-6 messenger ribonucleic acid by human pituitary adenomas.

Preliminary studies have demonstrated that some pituitary adenomas secrete immunoreactive interleukin-6 (irIL-6) when cultured in vitro. We have extended these studies by investigating 100 pituitary adenomas of different types measuring immunoreactive and bioactive IL-6. Tumors were cultured either as explants without fetal calf serum or as dispersed cells with 10% total calf serum.

T cells and thyroid autoimmunity.

Autoimmune thyroid disease is the archetype of organ-specific autoimmune disorders and shares with them T cell dependence. The observation that thyroid cells in autoimmune thyroid disease express the major histocompatibility complex molecule HLA-DR led to the hypothesis that they could present antigen and initiate or maintain the autoimmune process. However, functional experiments, and recent evidence indicating that provision of a co-stimulatory signal is also essential for efficient antigen presentation, argue against such a role.

Major histocompatibility complex class-II alleles in primary biliary cirrhosis.

The major histocompatibility complex (MHC) class-II alleles at the DRB1, DQB1 and DPB1 loci were investigated in 40 patients with primary biliary cirrhosis (PBC) and 43 local healthy controls. Restriction fragment length polymorphism (RFLP) was used for DRB1 typing. DQB1 and DPB1 regions were amplified using the polymerase chain reaction (PCR) and then probed with 32P-labelled allele-specific oligonucleotide probes.

The potential immunological role of the thyroid cell in autoimmune thyroid disease.

Over the last decade it has become evident that thyroid follicular cells express a number of immunologically active molecules in autoimmune thyroid disease that may endow them with the capacity to interact with cells of the classical immune system. Expression of major histocompatibility complex class II molecules is induced by gamma-interferon, but there is no evidence yet that thyroid follicular cells can concurrently express the costimulatory signals necessary for class II expression to result in T cell stimulation: in this situation, class II expression may have a protective role, inducing T cell anergy. Thyroid follicular cells also express a variety of cell surface proteins (in particular CD59) that may protect the cells from complement attack.

The gamma delta T cell repertoire in Graves' disease and multinodular goitre.

gamma delta T cells are a subset of T cells with unknown function, and restriction of the gamma delta T cell receptor (TCR) repertoire has been described in rheumatoid arthritis and multiple sclerosis. Elevated numbers of gamma delta T cells have been reported in the peripheral blood and thyroids of patients with Graves' disease. We have carried out flow cytometric analysis on peripheral blood mononuclear cells (PBMC) and intrathyroidal lymphocytes (ITL) from 12 patients with Graves' disease and nine patients with multinodular goitre (MNG), a thyroid disease of unknown etiology.

Adhesion molecule monoclonal antibodies inhibit experimental autoimmune thyroiditis.

To examine the role played by adhesion molecules in thyroid autoimmunity, we have assessed the effect of administering monoclonal antibodies (mAb) against intercellular adhesion molecule-1 (ICAM-1) and lymphocyte function-associated antigen-1 (LFA-1) in experimental autoimmune thyroiditis, induced by immunizing rats with thyroglobulin in complete Freund's adjuvant. The antibody against LFA-1, but not against ICAM-1, reduced thyroglobulin antibody production (P < 0.01) and both antibodies caused a significant reduction (P < 0.

IL-2 receptor-positive intrathyroidal lymphocytes in Graves' disease. Analysis of V alpha transcript microheterogeneity.

There has been considerable interest recently in the possible restriction of the TCR repertoire in autoimmune disorders, because such restriction would have important therapeutic implications. Reports of restriction of the TCR V alpha but not V beta repertoire in the thyroid in Graves' disease could not be repeated in an earlier study. Using RNA derived from matched peripheral blood, thyroid tissue, intrathyroidal lymphocytes (ITL), and IL-2R+ and IL-2R- subpopulations of ITL from Graves' patients, we conducted reverse transcription polymerase chain reaction/Southern blot analysis of TCR V alpha family usage.

Adrenocorticotropic hormone receptor-blocking immunoglobulins in serum from patients with Addison's disease: a reexamination.

The presence of antibodies inhibitory to ACTH-stimulated cortisol secretion was investigated in patients with Addison's disease. In preliminary experiments, immunoglobulin G (IgG) samples from patients with Addison's disease and control subjects were prepared using diethylaminoethyl-cellulose ion exchange chromatography. Twelve of 29 Addison's IgGs and 1 of 3 control IgGs inhibited ACTH-stimulated cortisol secretion in an in vitro guinea pig adrenal cell bioassay.

Extrathyroidal complications of Graves' disease.

Ophthalmopathy, pretibial myxoedema and acropachy are progressively less common features of Graves' disease with unknown but probably related aetiologies (Table 1). Treatment for affected eyes and skin is unsatisfactory and will only improve when we understand the pathogenesis of these complications and their arcane relationship with thyroid autoimmunity. This brief review will highlight recent research which suggests that fibroblast activation is critical to the appearance of ophthalmopathy and dermopathy; more general overviews can be found elsewhere.

T cell receptor beta chain gene polymorphisms in Graves' disease.

Graves' disease, or subgroups of such patients with thyroglobulin antibodies or HLA-DR3, have been associated with a restriction fragment length polymorphism of the T cell receptor beta chain constant region gene but not all studies are in agreement. We have examined 58 patients with Graves' disease and found no abnormal distribution of this polymorphism compared to 33 controls. There was also no significant association with the presence of thyroglobulin antibodies or HLA-DR3, even when the results were pooled with previously collected data (N = 90 patients with TG antibody results and N = 128 patients with HLA-DR types).

No restriction of intrathyroidal T cell receptor V alpha families in the thyroid of Graves' disease.

Recently it has been reported that the intrathyroidal T cells in Graves' disease display restriction in V alpha T cell receptor (TcR) gene family usage, although this is not found with TcR V beta gene families in the same individuals. We have performed a qualitative analysis of TcR V alpha family usage in 12 patients with Graves' disease by reverse transcription and polymerase chain reaction (PCR) amplification of RNA extracted from isolated, unstimulated intrathyroidal lymphocytes and from snap-frozen whole thyroid specimens. No restriction was observed, with 10-15 V alpha gene families being amplified in all cases.

Analysis of fibroblast-stimulating activity in IgG from patients with Graves' dermopathy.

Conflicting results have been reported on the effect of IgGs from patients with Graves' dermopathy on dermal fibroblast function. We have analyzed 14 dermopathy IgGs prepared by protein G affinity chromatography. These caused FRTL-5 thyroid cells to synthesize significantly greater amounts of glycosaminoglycans (GAG) and protein than IgGs from normal controls (p < 0.

Immunoglobulin class and IgG subclass distribution of anticardiolipin antibodies in patients with systemic lupus erythematosus and associated disorders.

The class and subclass distribution of an antibody response may give insight into the stimulating mechanism and likely effector functions. IgA, IgG and IgM anticardiolipin antibodies (aCL) were quantified in a consecutive series of 200 samples sent to an autoimmune serology laboratory to determine the relationships between aCL responses of each of these antibody classes and, in particular, whether there was any utility in the measurement of IgA aCL. Positive results for one of the three aCL isotypes were found in 105 samples (53%), and in 41 samples IgA aCL was detected (21%).

Failure to find an association of blood group P1 with thyroid-associated ophthalmopathy.

Objective: Genetic factors have been proposed to account for the development of ophthalmopathy in a proportion of patients with Graves' disease. The aim of this study was to confirm the previously reported association between blood group P1 and thyroid-associated ophthalmopathy.

Design: A prospective study of sequential Caucasian patients.

Analysis of anti-idiotypic antibodies against anti-microsomal antibodies in patients with thyroid autoimmunity.

Anti-microsomal antibody (AMA) activity was inhibited in 14 of 16 sera and in all 12 IgG preparations from patients with postpartum thyroiditis following incubation with F(ab')2 fragments from normal polyspecific immunoglobulin for therapeutic use (ivIg). Similar results were observed with sera from seven of seven patients with Graves' disease and five of six patients with autoimmune hypothyroidism. Results of these competitive binding assays and affinity chromatography of AMA IgG on Sepharose-bound F(ab'), fragments from ivIg indicated that AMA antibodies reacted with ivIg through idiotypic-anti-idiotypic interactions.

Antithyroid drugs and release of inflammatory mediators by complement-attacked thyroid cells.

Thyroid cells are exposed to complement attack in Graves' disease and Hashimoto's thyroiditis, but are resistant to killing by homologous complement. We have examined the effects of sublethal complement attack on thyroid cells in vitro. Extracellular reactive oxygen metabolites were produced and prostaglandin E2, interleukin-1 alpha, and interleukin-6 were released after complement attack.

T cell responses to synthetic TSH receptor peptides in Graves' disease.

Twenty-eight peptides, representing the entire extracellular domain of the TSH receptor, were synthesised to investigate which parts of this autoantigen may be targets for the T cell response in Graves' disease (GD). T cells from 11 of 21 controls and 26 of 36 newly diagnosed GD patients proliferated in response to one or more peptides with a stimulation index (SI) of greater than 2.0 (chi 2 = 2.

Thyroid cells in Graves' disease and Hashimoto's thyroiditis stimulate allogeneic T cells when pretreated with phorbol ester.

Objective: To assess the capacity of thyroid follicular cells to function as antigen presenting cells, we have examined their ability to stimulate allogeneic T cells.

Design: Thyroid follicular cells were pretreated with interferon-gamma or phorbol myristate acetate, washed thoroughly, and their capacity to induce allogeneic T cell proliferation was determined.

Patients: Thyroid cells were prepared using thyroidectomy specimens from eight patients with Graves' disease, one with Hashimoto's thyroiditis and two with non-toxic multinodular goitre.