Thyroid-infiltrating T lymphocyte subsets in Hashimoto's thyroiditis

Effects of angiotensin II blockade on the development of autoimmune thyroiditis in nonobese diabetic mice

We evaluated the effects of angiotensin II (Ang II) blockers, losartan, an Ang II receptor blocker, and enalapril, an angiotensin converting enzyme inhibitor, on the development of autoimmune thyroiditis in nonobese diabetic (NOD) mice, an animal model of Hashimoto's thyroiditis (HT). Mice were assigned into three groups, untreated, losartan-treated (30 mg/kg/day), and enalapril-treated (10 mg/kg/day) groups. Thyroiditis was induced by iodide ingestion (experiment 1) or mouse thyroglobulin (Tg) immunization (experiment 2). Both procedures effectively induced thyroiditis. While iodide ingestion failed to induce anti-mouse Tg antibody (TgAb) production, Tg immunization resulted in a significant increase in serum TgAb levels. In both experiments, neither losartan nor enalapril interfered with the development of thyroiditis and TgAb production. These results suggest that Ang II may not be associated with the development of autoimmune thyroiditis in NOD mice. Thus, the Ang II blockade may not have therapeutic potential in HT.

Dermatologic aspects of thyroid disease

Thyroid disorders commonly have dermatologic manifestations. The purpose of the present chapter is to review and emphasize potential clinical dermatologic findings that can occur with Graves' disease, hypothyroidism and thyroid cancer. In autoimmune diseases such as Graves' disease and Hashimoto's thyroiditis the skin manifestations may be related to either thyroid hormone levels themselves or to the associated T and/or B cell abnormalities. Thyroid cancer may be associated with various syndromes that could have significant skin manifestations.

Spontaneous lymphocyt ic thyroiditis in interferon regulatory factor-1 deficient non-obese diabetic mice

Interferon regulatory factor-1 (IRF-1) is a transcription factor involved in interferon-mediated immune reaction, CD8+ T cell differentiation and development of T helper 1 immune reaction. We have recently demonstrated that IRF-1 is pivotal in iodine-induced lymphocytic thyroiditis (LT) in non-obese diabetic (NOD) mice. However, it remains unclear whether the mechanism involved in spontaneous LT is identical with iodine-induced LT in NOD mice. To determine the role of IRF-1 in spontaneous LT, we used IRF-1 deficient NOD mice as well as IRF-1 +/+ and +/- mice which were free from treatments for LT induction, and LT was evaluated at 24 weeks of age. IRF-1 +/+, +/- and -/- mice developed LT spontaneously, and there were no differences among the 3 IRF-1 genotypes in the incidence and severity of LT. Whereas both CD4+ and CD8+ T cells were present in the diseased thyroid of IRF-1 +/+ mice, CD8+ T cells were absent in the thyroid of IRF-1 -/- mice. MHC class II antigen expression was induced in the inflamed thyroid of IRF-1 -/- mice comparable to IRF-1 +/+ mice. There was a selective reduction in the number of CD8+ T cells in the spleen of IRF-1 -/- mice. IFNgamma production, but not IL-10, by concanavalin A-stimulated splenocytes was significantly reduced in IRF-1 deficient mice. These results suggest that IRF-1 plays only a minor role in spontaneous LT in NOD mice and, furthermore, the mechanism involved in spontaneous LT is different from that of iodine-induced LT in NOD mice.

Induction of experimental autoimmune thyroiditis by heat-denatured porcine thyroglobulin: a Tc1-mediated disease

Recent studies have shown that denatured exogenous antigens can prime cytotoxic T lymphocytes (CTL). To assess the contribution of CTL to experimental autoimmune thyroiditis (EAT), porcine thyroglobulin (pTg) was heat-denatured (hdpTg) and injected i.v. into CBA/J mice, without the aid of adjuvants. Both lymphocytic infiltrations of the thyroid glands and levels of Tg-specific CTL were similar to those found in conventional EAT induced by Tg and adjuvants. In contrast, proliferative responses could not be detected, and titers of antibodies to pTg were 20 times lower. These EAT-inducer CTL belong to the CD8+ cell subset and exerted their thyroiditogenic potential through release of IFN-gamma. We conclude that hdpTg-induced EAT is mediated by type 1 cytotoxic T cells (Tc1).

Usefulness of surface phenotype study of intrathyroidal lymphocytes obtained by fine needle aspiration cytology in autoimmune thyroid disease and malignant lymphoma of the thyroid

OBJECTIVES

The surface phenotypes of intrathyroidal lymphocytes have been studied in various thyroid diseases. In most of the previous reports, intrathyroidal lymphocytes were obtained by surgical operation. We evaluated the usefulness of surface phenotype study of intrathyroidal lymphocytes obtained by fine needle aspiration in the diagnosis of Graves' disease, chronic thyroiditis, and malignant lymphoma of the thyroid.

PATIENTS AND DESIGN

Eighty-seven untreated patients including 24 with Graves' disease, 59 with chronic thyroiditis, and 4 with malignant lymphoma of the thyroid, and 2 treated patients with malignant lymphoma of the thyroid were studied. Surface phenotypes of the peripheral lymphocytes and the intrathyroidal lymphocytes obtained by fine needle aspiration were analyzed using a FACScan and the monoclonal antibodies: anti-Leu5b/CD2, Leu4/CD3, Leu3a/CD4, Leu2a/CD8, and Leu12/CD19. Percentages of cells positive for each monoclonal antibody were calculated. In one case with malignant lymphoma, monoclonal antibodies to surface-immunoglobulin markers were also studied.

RESULTS

In peripheral lymphocytes, the percentage of positive cells in each phenotype was almost normal in each disease. In intrathyroidal lymphocytes, the percentage of CD19 positive cells was increased, and the percentage of CD2 and CD3 positive cells was reduced compared to those of peripheral lymphocytes in each disease. The percentage of intrathyroidal CD19 positive cells was remarkably high in malignant lymphoma, constituting more than 70% of cells. In Graves' disease, a relative decrease in the percentage of intrathyroidal CD4 positive cells and an increase in CD8 positive cells compared to peripheral lymphocytes were observed. In 2 treated patients with malignant lymphoma of the thyroid, the intrathyroidal CD19 positive cells almost disappeared in a patient shortly after successful treatment, and reappeared to constitute 76% of cells in a patient in relapse. In one case with malignant lymphoma in which monoclonal antibodies to surface-immunoglobulin markers were studied, the clonality of the affected cells could be demonstrated; more than 70% of the cells were positive for kappa light-chain and mu and delta heavy-chain. This finding was proved by subsequent immunohistochemical study based on open biopsy.

CONCLUSIONS

Surface phenotype study of intrathyroid lymphocytes obtained by fine needle aspiration has limited utility in the evaluation or diagnosis of Graves' disease and chronic thyroiditis. However, this simple rapid method is very helpful in the diagnosis and follow up of malignant lymphoma of the thyroid.

Warthin-like tumor of the thyroid: a papillary carcinoma with mitochondrion-rich cells and abundant lymphoid stroma. A case report

Papillary carcinoma is the most common form of thyroid carcinoma and, generally, it has a more favorable prognosis than other carcinoma types, although diverse variants or subtypes have been described, some of which appear to have a less favorable prognosis. Recently, a new variant, the so-called "Warthin-like tumor" or "tall-cell variant with extensive lymphocytic infiltration of papillary thyroid carcinoma" with behavior similar to the usual papillary carcinoma, has been described. We present a case with the cytohistological pattern of "Warthin-like tumor" of the thyroid. Immunohistochemistry revealed reactivity at the epithelium lining papillae for antimitochondrial 113-I antibody and also membranous positivity for CD15 (Leu M1). Lymphoid stroma showed an immunoprofile similar to chronic lymphocytic thyroiditis. These findings point to the consideration of "Warthin-like tumor" as being a hybrid neoplasm between the tall-cell variant and oxyphilic papillary carcinoma associated to a lymphoid-rich stroma.

Papillary carcinoma of the thyroid. Tall-cell variant with extensive lymphocyte infiltration

Thirteen cases of tall-cell variant of papillary thyroid carcinoma (PTC) showing extensive lymphocyte and plasma cell infiltration within the fibrous stalks of the papillary architecture were compared with age-, sex-, and tumor size-matched cases of ordinary tall-cell variant without extensive lymphocyte infiltration and also with cases of PTC of the conventional type. All cases of the tall-cell variant of PTC with extensive lymphocyte infiltration exhibited the histologic features of chronic thyroiditis. Dissemination of tumor cells with the thyroid was significantly less frequent than in control cases, but there was no difference between the incidences of lymph node metastasis. Immunohistochemically, the lymphocytes infiltrating the carcinoma focus were mainly CD20+, CD45+, and CD45RO+ cells, that is, basically the same as those found in foci of chronic thyroiditis. No tumor recurrence was observed during the mean follow-up period of 3 years 8 months. The results of this study suggest that the tall-cell variant of PTC with extensive lymphocyte infiltration has less aggressive characteristics and a more favorable prognosis.

Cytokines and immune regulation in thyroid autoimmunity

We studied the role of cytokines and immune regulation in thyroid tissue from patients with Graves' disease. Immunohistochemistry showed that the thyroid glands are characterized by an aberrant expression of HLA class II antigens on thyrocytes, generation of new blood vessels and infiltration of mononuclear cells. We demonstrated that CD4+ memory cells were more frequent in thyroid glands from Graves' patients than were CD4+ naive cells. The intrathyroidal T cells demonstrated an enhanced expression of the adhesion molecules LFA-1, CD2, VLA-4 and VLA-5, and vascular endothelial cells of capillaries and thyrocytes in thyroid glands reacted with anti-ICAM-1 monoclonal antibody. The adhesion molecules and HLA antigens on both vascular endothelial cells and thyrocytes were regulated by inflammatory cytokines. These results suggest that circulating lymphocytes migrate into thyroid tissues and that memory T cells are retained in the thyroid tissues by cellular interactions with thyrocytes or with extracellular matrix.

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.

Intrathyroidal activated (Ia+) T-lymphocyte CD+ subsets and B cells in Graves' hyperthyroidism respond rapidly to propylthiouracil therapy: demonstration using fine needle aspirates and two-colour laser flow cytometry

Using a rapid (whole blood lysis) single laser microfluorocytometric technique that permitted the simultaneous analysis of two monoclonal antibody surface markers tagged with different fluorescent dyes, the intrathyroidal (IT) and peripheral blood (PB) activated [Ia+ = DR+] T-lymphocyte CD3+ subsets and [F(ab')2+] B cells were studied in hyperthyroid patients with Graves' disease (GD) before and after 1-4 months of propylthiouracil (PTU) therapy. IT lymphocytes were obtained by serial fine needle aspiration. In untreated patients a marked quantitative (approximately < 10 fold) increase in activated (Ia+ CD3+) T-lymphocytes as well as CD4+ and CD8+ subsets, for IT compared to PB sites, was found. The percentages of Ia+ CD4+ and Ia+ CD8+ within Ia+ CD3+ were not significantly different between the two sources of T cells. F(ab')2+. B cells were significantly increased (approximately 2-3 fold) in IT compared to PB. In hyperthyroid GD patients, PTU therapy induced rapid and specific changes within the Ia+ CD3+ subsets, namely a reduction in the Ia+ CD4+ subset and an increase in the Ia+ CD8+ subset, resulting in a marked decrease in the Ia+ CD4+/Ia+ CD8+ ratio. These changes occurred in association with a reduction in serum T4 and T3 concentration. No significant changes could be detected within the total (predominantly non-activated) CD3+, CD4+ or CD8+ lymphocyte subsets within PB and only a small decrease in the CD4+/CD8+ ratio was demonstrated in IT, following PTU treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Evidence of limited variability of antigen receptors on intrathyroidal T cells in autoimmune thyroid disease

BACKGROUND

Patients with autoimmune thyroid diseases, including Graves' disease and Hashimoto's disease, have marked lymphocytic infiltration in their thyroid glands. We examined the gene for the variable regions of the alpha-chain of the human T-cell receptor (the V alpha gene) in intrathyroidal T cells to determine whether the infiltration is a secondary heterogeneous immune response or a more restricted, and therefore primary and presumably pathogenetic, reaction to thyroid autoantigens.

METHODS

We used the polymerase chain reaction to detect small numbers of T cells expressing the variable region of the V alpha gene. Different oligonucleotides were used to amplify complementary DNA for the 18 known families of the V alpha gene in intrathyroidal T cells from 9 patients with autoimmune thyroid disease. We compared the findings with the results in patients with nonautoimmune thyroid disease as well as those in normal subjects.

RESULTS

We found marked restriction in the expression of T-cell-receptor V alpha genes by T cells from the thyroid tissue of patients with autoimmune thyroid disease. An average of only 5 of the 18 V alpha genes were expressed in such samples, as compared with 17 V alpha genes expressed in peripheral-blood T cells from the same patients. No such restriction was found in thyroid tissue from patients with nonautoimmune thyroid disease. The predominantly expressed V alpha genes differed from patient to patient, however, with no clear association with the type of disease.

CONCLUSIONS

Intrathyroidal T-cell accumulation in autoimmune thyroid disease is highly restricted and points to the primacy of T cells in causing thyroid disorders. These results present the possibility of using antibodies to the T-cell receptor for the specific inhibition of abnormal T-cell function in autoimmune thyroid disease.

Characterization of pancreatic T lymphocytes associated with beta cell destruction in the non-obese diabetic (NOD) mouse

Pancreatic beta cell destruction in the non-obese diabetic (NOD) mouse is mediated by T lymphocytes and macrophages and accelerated by cyclophosphamide. We purified pancreatic T lymphocytes from the NOD mouse for comparative phenotypic and functional analysis with T lymphocytes from spleen, peripheral blood and regional lymph nodes. Pancreatic T lymphocytes from NOD-Wehi mice, which have an incidence of spontaneous diabetes of less than 5%, had a CD4:CD8 ratio of 1.25 +/- 0.23 compared with 2.44 +/- 0.31 for peripheral blood lymphocytes. After cyclophosphamide, the CD4:CD8 ratio of pancreatic lymphocytes increased to 2.30 +/- 0.24 at day 7. T lymphocytes bearing IL-2 receptors increased two- to three-fold in number and their secretion of GM-CSF/IL-3 and IFN-gamma increased to a maximum on day 7. Pancreatic insulin content and mRNA levels declined sharply between days 10 and 12, at which time the majority of pancreatic T lymphocytes in hyperglycaemic mice were CD8+ (CD4:CD8 ratio 0.63 +/- 0.04 compared to 4.14 +/- 1.05 in peripheral blood). The pancreatic T lymphocyte CD4:CD8 ratio in prediabetic NOD-Lt mice, which have an incidence of spontaneous diabetes of about 60% at 150 days, was similar to that in untreated NOD-Wehi mice, but 25% of their pancreatic CD8 T lymphocytes were IL-2-receptor positive. Thus, significant changes in the phenotype of NOD pancreatic T lymphocytes following cyclophosphamide were not reflected in peripheral blood or spleen T lymphocytes. The earliest change after cyclophosphamide was an increase in activated, predominantly CD4+ T lymphocytes; with the development of beta cell destruction and hyperglycaemia, pancreatic T lymphocytes were, as in human IDDM, predominantly CD8+.

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.

Malignant Lymphoma of the Thyroid

Thyroid lymphoma is a relatively rare disease, but has attracted the attention of many investigators because of its putative relationship with chronic lymphocytic thyroiditis (CLTH). The definite diagnosis of thyroid lymphoma, especially the histologic distinction from small cell carcinoma or CLTH, has been problematical and even regarded as impossible during the past decades. Recent progress in immunological methods including moltxular biology have resolve'd many of the diagnostic problems in this field, thereby providing a scientific basis for approaching these diseases. In this review, we have summarized the results of our recent study on thyroid lymphoma reviewing the pertinent literature. Briefly, we have discussed the important role of CETH in the etiology of thyroid lymphoma; the histologic classification of thyroid lymphoma, with special emphasis on the rellatively high incidence of intermediate lymphocytic lymphoma; the B-cell nature of proliferating cells in thyroid lymphoma; the prognostic significance of the histologic classification Working Formulation and other clinical factors; local immunologic conditions in the thyroid affected by lymphoma compared with those encountered in CLTH alone and the positive role of aspiration cytology in the early detection of thyroid lymphoma.

The significance of T suppressor cells in the development of autoimmunity

Despite intensive research, autoimmune-disease pathogenesis is still an enigma, but in the past decade Ts-cell defects have assumed a central role in this pathogenesis. Ts-cell dysfunctions have been reported in numerous autoimmune diseases (e.g. SLE, autoimmune thyroid disease, myasthenia gravis) and in animal models of autoimmune diseases. Therefore, it is currently believed that Ts cells are responsible for maintaining self-tolerance and that perturbations in suppressor functions may initiate development of autoimmune diseases. Ts-cell abnormalities can result from LCTA production, intrinsic biochemical alterations, genetic susceptibility, or environmental factors. Since Ts-cells dysfunctions are believed to initiate autoimmunity, it may be possible to treat autoimmune diseases by correcting the suppressor defects, and indeed, preliminary trials in this direction are promising.

In situ kinetic analysis of thyroid lymphocyte infiltrate in mice developing experimental autoimmune thyroiditis

L3T4+ T cells from genetically susceptible mice developing experimental autoimmune thyroiditis (EAT) were shown earlier to proliferate in response to restimulation with mouse thyroglobulin (MTg) in vitro and to mediate the adoptive transfer of EAT, whereas Lyt-2+ cells differentiated in vitro into cells cytotoxic for thyroid monolayers. Leukocyte suspensions from disrupted thyroid glands examined on Days 13-21 after immunization revealed the accumulation of both T cell subsets in the infiltrate at varying ratios. To characterize the in situ kinetics of cellular infiltration in chronic EAT, we extended the observation intervals after immunization to include Days 21 to 42. The leukocytes in thyroid sections were labeled immunohistochemically first with rat monoclonal antibodies to L3T4, Lyt-2, Thy-1, k light chain, or F4/80 macrophage antigen, then with biotinylated anti-rat IgG, utilizing the avidin-biotin-peroxidase technique. Throughout the 21- to 42-day interval, no significant variations were detected in the percentages of L3T4+ subset, but those of Lyt-2+ cells increased and then declined. The shift in the L3T4+:Lyt-2+ ratio, down from 2.4 to 1.6 and then up to 3.0, was directly related to changes in the Lyt-2+ subpopulation. The F4/80+ and B cell populations changed little during this period. These findings illustrate the changing kinetics of T cell subsets in situ in the development and perpetuation of EAT and MTg-immunized mice.

Intrathyroidal HLA-DR-positive lymphocytes in Hashimoto's disease: increases in CD8 and Leu7 cells

The peripheral and intrathyroidal HLA-DR-positive (DR+) lymphocyte subsets that were activated in vivo in patients with Hashimoto's disease (HD) were examined by two-color flow cytometry with monoclonal antibodies against CD3, CD4, CD8, Leu7, CD19, and HLA-DR antigens. The proportions of total DR+ cells in peripheral lymphocytes and the proportions of DR+ cells in the CD3+, CD4+, and Leu7+ lymphocytes were higher in patients with HD than in normal controls. Furthermore, the proportions of total DR+ cells among intrathyroidal lymphocytes isolated from thyroid tissue of individuals with HD were higher than those in their peripheral lymphocytes. Interestingly, the proportions of DR+ cells among the CD3+, CD8+, and Leu7+ lymphocytes in the thyroid were greatly increased. These data indicate that (i) CD3+ T, especially CD4+ T helper/inducer, lymphocytes and Leu7+ NK/K cells are activated in peripheral blood in Hashimoto's disease and that (ii) CD3+ T, especially CD8+ T suppressor/cytotoxic, lymphocytes and Leu7+ NK/K cells are predominantly activated in Hashimoto's goiter, suggesting an increase of cell-mediated cytotoxicity in the thyroid in Hashimoto's disease.

Investigation of the clonality of lymphocytes in Hashimoto's thyroiditis using immunoglobulin and T-cell receptor gene probes

Southern blotting and DNA hybridization were used for the detection of immunoglobulin and T-cell receptor gene rearrangements in thyroid tissue from six patients with Hashimoto's thyroiditis, three patients with B-cell lymphoma complicating Hashimoto's thyroiditis, and two patients with nonspecific lymphocytic thyroiditis. Immunoglobulin gene rearrangements were detected only in patients with histologic evidence of lymphoma. A single T-cell receptor beta-chain gene rearrangement was detected in one of the patients with uncomplicated Hashimoto's thyroiditis. Based on our knowledge of primary thyroid lymphomas, it is highly unlikely that this case represents an early, histologically occult T-cell lymphoma. The uniform lack of immunoglobulin gene rearrangements in Hashimoto's thyroiditis supports the use of genotypic analysis in differentiating between uncomplicated Hashimoto's thyroiditis and non-Hodgkin's lymphoma. The finding of a T-cell receptor gene rearrangement in a case of Hashimoto's thyroiditis suggests that the immune response in this disease occasionally may be clonally restricted.

Autoimmune thyroid disease: immunological, pathological, and clinical aspects

Autoimmune thyroiditis, most notably Hashimoto's thyroiditis, appears to be increasing in prevalence and is now more easily detected by sensitive laboratory tests and more invasive procedures such as fine needle aspiration. During the last decade, marked progress has been made in the understanding of these diseases. There is a greater awareness of the interaction between the humoral and cell-mediated arms of the immune system in autoimmune thyroiditis. Recent studies implicate a subpopulation of suppressor T lymphocytes which have an antigen-specific defect, resulting in their suboptimal interaction with the helper T lymphocytes and subsequent autoimmune manifestations. There is some evidence that thyroid epithelial cells which inappropriately express HLA-DR may enhance presentation of thyroid antigens to the immune system, possibly significant in the initiation or enhancement of the autoimmune response. The presence of various antithyroid autoantibodies allows the use of laboratory assays to confirm the clinical diagnosis and predict the results of treatment. There appears to be predisposing genetic factors in the development of autoimmune thyroiditis, with some geographical and racial differences. Environmental factors, most notably dietary intake of iodine, have also been implicated in the pathogenesis of Hashimoto's thyroiditis. Several animal models have been developed addressing such issues. Ongoing studies in the areas of postpartum thyroiditis and childhood thyroiditis are helpful in clarifying their relationship with Hashimoto's thyroiditis. Graves' disease and postpartum thyroiditis are being investigated as possible causes of postpartum depression. The association of Hashimoto's thyroiditis and carcinoma of the thyroid gland is still controversial, but its relationship with malignant lymphoma is now well accepted. Thus, although the pathogenesis of autoimmune thyroiditis remains elusive, there has been significant refinement of the clinical diagnosis, and immunological abnormalities of specific intrathyroidal lymphocytes have been identified. Hopefully, these new areas of knowledge will assist in the treatment of these diseases and in the prevention of the development of malignant lymphomas of the thyroid gland.

Separation and analysis of mononuclear cells infiltrating the thyroid of patients with Graves' disease

A simple method was established for separating lymphocytes infiltrating the thyroid from thyroid epithelial cells. Namely, suspensions of minced thyroid from patients with Graves' disease were layered on a Percoll two-step density gradient (p = 1.050 and 1.077 g/ml) and centrifuged (400g, 30 min, 4 degrees C). In this way 0.1-18 X 10(5) lymphocytes/g of thyroid tissue with a purity of 65-95% were obtained. Thyroid lymphocytes were analyzed quantitatively with monoclonal antibodies by laser flow cytometry and compared with peripheral lymphocytes. The proportion of OKT3+ cells was decreased with increase in OKIa+ cells. The percentage of OKIa+ cells was significantly correlated with that of Leu12+ cells. The percentages of OKT4+ cells and OKIa+ cells were higher when analyzed with an extended gate window, which was arranged for detection of activated, large-sized lymphocytes. The percentages of OKT8+ and Leu7+ cells were not significantly different from those in peripheral blood. From these results it was concluded that the proportion of B lymphocytes is increased and that of T lymphocytes is decreased, the proportion of activated B lymphocytes is increased, some helper/inducer T cells are activated in the thyroid gland in Graves' disease, and these activated lymphocytes may be important in local production of antithyroid autoantibodies.

Cell-mediated immunity in autoimmune thyroid disease

The initiation of an autoimmune response requires the establishment of an appropriate microenvironment. This, in turn, involves several requirements, including antigen expression on the membrane surface of the target cells, class II antigen expression on the antigen-presenting cell or target cell, a relative systemic or local increase in the helper/inducer subset of T cells, and/or a relative decrease in the suppressor subset of T cells. All of these conditions have been described in the thyroid gland. Appropriate cellular interactions result in the appearance of activated T cells and the generation of cytotoxic T cells. The pathologic alterations may be produced by the local production of antibody and subsequent formation of immune complexes, by direct lymphocyte damage, or by lymphokine production. Autoimmune thyroid disease remains, to our minds, the most instructive paradigm of the organ-specific autoimmune endocrinopathies.

The familial occurrence of lymphocytic thyroiditis in borzoi dogs

A group of related borzoi dogs were studied over a 6-year period to ascertain the cause of primary hypothyroidism. Four generations of dogs were analyzed. Two littermates with lymphocytic thyroiditis were mated and the 10 offspring were all diagnosed, on the basis of thyroid biopsy evaluation, as having lymphocytic thyroiditis by age 2.5 years. A wide range of thyroid gland lesions was demonstrated in this litter of dogs. This report documents the occurrence of lymphocytic thyroiditis in three successive generations of an inbred group of borzoi dogs. An autosomal recessive mode of inheritance for the trait in this group of dogs is proposed.

[Diagnostic procedure in suspected functional disorders of the thyroid gland]

In an attempt to derive diagnostic concepts for thyroid diseases we present pathophysiological models for the prevalent thyroid disorders. 'Euthyroid goiter' is a disease mainly caused by iodine deficiency but an additional immunopathogenesis was recently proposed. The 'immunthyropathy' is the thyroid disease with orbitopathy and other extraglandular immunological manifestations. A complete model of the immunological phenomena which begin with a tolerance defect is given, and both the T-cell, and B-cell-mediated pathways are detailed. The complex interaction of immunoglobulins at the thyroid-stimulating hormone receptor and their dependency on human leukocyte antigen loci are presented. The peripheral metabolism depends ultimately upon a prevalence of thyroid gland stimulation (thyrotoxicosis) or glandular destruction (hypothyroidism) and this is true for overt thyroid disease under antithyroid drug therapy or any other therapy. Euthyroidism during 'immunethyropathy' is presented as an equilibrium between thyroid stimulation and destruction. This concept allows an exact description of the thyroid disease and the resulting clinical situation provided that established laboratory tests are used as suggested by the model. 'Disseminated thyroid autonomy and autononous thyroid adenoma' develops during goitrous thyroid disease as a consequence of uncoupling of thyroid cellular growth stimulation, iodine utilization, and thyroid hormone synthesis. The polyclonal origin seems more frequent than monoclonal foci. The size of autononous tissue and individual iodine supply determines the endocrine function in this disease. The TRH test monitors with great sensitivity subtle increases in T4 or T3 production and indicates critical clinical situations earlier than the scintiscan.(ABSTRACT TRUNCATED AT 250 WORDS)

Autoimmune thyroid disease: purification and phenotypic analysis of intrathyroid T cells

A phenotypic analysis of T cells infiltrating the thyroid of patients with autoimmune thyroid disease (both Graves' disease and Hashimoto's thyroiditis) was performed. T lymphocytes were purified from mononuclear cells extracted from surgically removed tissue. The following markers were evaluated: la antigens, MLR4 antigen (expressed on activated T cells) 5/9 antigen (expressed on a subset of lymphocytes containing the whole "helper-inducer" activity in vitro), Fc gamma-receptors, B9 antigen (expressed by cytotoxic, or precursor of cytotoxic, T cells). We observed increased percentages of 5/9-, MLR4- and la-positive T cells with respect to peripheral blood in both HT and GD: on the contrary, in specimens from nonautoimmune thyroid diseases mononuclear infiltrate was minimal, and even T cell evaluation was not possible. In addition, B9- and Fc gamma-positive T cells were increased in Hashimoto's, but not in Graves' thyroid tissue, thus suggesting a different role of cytotoxic effector mechanisms in the two diseases.

B- and T-lymphocytes in ocular disease

Ocular inflammatory diseases and ocular adnexal lymphoid tumors have become less obscure and intimidating by virtue of our ability to study the infiltrates in these various diseases for their B-lymphocyte and T-lymphocyte composition. Comparisons are also possible between lymphocytic profiles in the peripheral blood and the precise composition of the in situ infiltrates within the ocular tissue themselves. The availability of monoclonal antibodies, which can determine T-lymphocytic subsets such as T-helper cells and T-suppressor/cytotoxic cells, natural killer cells, and monocytes-histiocytes, has provided a powerful technology for the delineation of the distinctive immune composition of the inflammatory infiltrates, as well as any possible disturbances in T-cell immunoregulation. B-lymphocytes produce immunoglobulins, which may be misdirected as autoantibodies in local or systemic autoimmune diseases. Immunoglobulin-mediated and therefore B-cell derived conditions include vasculitis, progressive cicatricial ocular pemphigoid, Mooren's corneal ulcer, scleritis, and hay fever and vernal conjunctivitis. Other diseases in which B-lymphocytes, their immunoglobulin products or immune complexes formed with presently unknown antigens are potentially at fault are chronic non-specific uveitis; iridocyclitis in Behcet's syndrome; Fuch's heterochromic syndrome, ankylosing spondylitis, and Reiter's syndrome; Graves' disease; and idiopathic inflammatory orbital pseudotumor and myositis. T-cells do not produce immunoglobins, but rather secrete lymphokines or interact directly with receptors or determinants on viruses or target tissues (eg. immunosurveillance against neoplasia); it is possible that some autoimmune diseases are the result of neo-antigens on the surfaces of host tissues that have been coded for by a cryptic inciting virus. T-cell diseases include phlyctenulosis graft rejections, graft versus host disease, and possibly sympathetic ophthalmia and temporal arteritis. Natural killer cells are involved in many of the same diseases as cytotoxic T-cells, except that the former require no period of sensitization (natural immunity), whereas cytotoxic T-cells must undergo an antigen-specific blast transformation (acquired immunity of the delayed hypersensitivity type). In many diseases in which B-cell derived auto-antibodies are at fault, there may be local tissue or systemic T-cell imbalances, with a reduction in T-suppressor cells and a relative augmentation in T-helper cells, thereby facilitating production of misdirected auto-antibodies.(ABSTRACT TRUNCATED AT 400 WORDS)

Primary biliary cirrhosis--phenotypic characterization of immunocompetent cells in peripheral blood and liver tissue

Circulating T-cell subsets have been characterized in 18 patients with primary biliary cirrhosis (PBC) using a simple immunoenzymatic staining method on stored and prefixed cell samples. Furthermore, a double immunoenzymatic method was used to study T-cell subsets and their relationship to HLA-DR+ cells in frozen sections of liver biopsies from 12 patients with PBC. In 10 cases blood and liver samples were taken simultaneously from the same patient. Patients with PBC of early histological stage showed an elevated absolute number of helper/inducer T-cells (Leu 3a+) and reduced relative percentages of suppressor/cytotoxic T-cells (Leu 2a+) compared with healthy subjects resulting in an elevated helper/suppressor ratio. Liver biopsies in PBC were dominated by helper inducer phenotype T-cells in all cases irrespective of histological stage, penicillamine treatment or the relative levels of circulating T-cell subsets. A relatively high amount of HLA-DR+ cells were seen, several of these in close approximation to T-cells.