Intrathyroidal Lymphocytes Research Articles

Postpartum thyroiditis. A clinical, histologic, and immunopathologic study of 15 cases.

Fifteen specimens from 15 patients with clinically and laboratory-proven postpartum thyroiditis were examined histologically; 8 specimens were obtained during the hypothyroid phase and the other 7 during the recovery euthyroid phase. All specimens showed focal or diffuse chronic thyroiditis. In the eight specimens taken during the hypothyroid phase and four specimens during the early recovery phase, follicular disruption and hyperplastic change of the follicle were common and characteristic histologic features. In the three specimens taken during the late recovery phase, only focal infiltration of lymphocytes was observed. This histologic change resembled that in spontaneous silent thyroiditis, as shown in the authors' previous study. The authors believe that postpartum thyroiditis and spontaneous silent thyroiditis may fit the same category clinically and histologically. In addition to performing the histologic examination, the authors examined the intrathyroidal lymphocyte subsets and HLA-DR antigen expression in the follicular cells immunohistochemically and compared them with those in chronic thyroiditis (usual type). In postpartum thyroiditis, a significant increase of helper-T-cell numbers and increased expression of HLA-DR antigen in the follicular cells were observed, suggesting an enhancement of autoimmune reactivity.

Studies of thyroid xenografts from Graves' disease in severe combined immunodeficient mice.

Thyroid tissues from normal (paranodular) subjects and patients with Graves' disease (GD) and Hashimoto's thyroiditis (HT) were xenografted to severe combined immunodeficiency (SCID) mice, and the same tissues were engrafted into nude mice; in addition, peripheral blood mononuclear cells were engrafted to separate SCID mice (SCID-PB). Thyroglobulin (TG) and microsomal antibodies (Abs) became detectable with high titers by hemagglutination assays in SCID mice xenografted with thyroid tissues (SCID-TH) from GD and HT patients; moreover, TG Ab was detectable even in SCID-TH from TG Ab-negative GD and HT donors. On the other hand, only 2 of 10 SCID-PB had detectable Abs with low titers. TSH receptor (TSH-R) Ab was detectable in all sets of SCID-TH from GD. After peaking (3-7 weeks), their levels decreased despite the fact that immunoglobulin G levels increased. In addition, in 3 of 4 sets of SCID-PB from GD patients, TSH-R Ab was also detectable. SCID-TH from GD and HT patients showed transient hyperthyroxinemia, peaking at 2 weeks; these values were significantly higher [free T4, 6.48 +/- 0.90 and 5.50 +/- 0.77 pmol/L (mean +/- SE), respectively; P < 0.05] than SCID-TH from normal controls (2.5 +/- 0.24). Histologically, intrathyroidal infiltrating lymphocytes (ITL) survived in SCID mice, but not in nude mice after 8 weeks. The follicles of GD tissue in SCID mice were virtually destroyed with ITL, and their appearance was similar to that in HT. In conclusion, TSH-R Ab was clearly produced from ITL, and some peripheral blood mononuclear cells grafts could also produce TSH-R Ab. In spite of the presence of TSH-R Ab, SCID-TH from GD patients did not show persistent hyperthyroxinemia, presumably because destructive thyroiditis may be occurring in the grafted tissue, with decreasing levels of TSH-R Ab.

Reconstitution of severe combined immunodeficient mice with intrathyroidal lymphocytes of thyroid xenografts from patients with Hashimoto's thyroiditis.

Thyroid tissues from patients with Hashimoto's thyroiditis (HT) have been xenografted to both severe combined immunodeficiency (SCID) mice and nude mice to study the intrathyroidal lymphocytes which were expected to migrate from the xenografts in the SCID mice. Peripheral blood mononuclear cells from HT, Graves' disease, and normal donors have also been separately engrafted. SCID mice, but not nude mice with HT thyroid grafts produce human immunoglobulins. More immunoglobulin G (IgG), but less IgM and IgA is produced in SCID mice with HT thyroid grafts (SCID-TH), compared to SCID mice injected with peripheral blood mononuclear cells from patients with HT or normal donors (SCID-PB), suggesting that different B cell subpopulations were active in the SCID-PB vs. SCID-TH. Production of IgG by SCID-PB and SCID-TH was maintained 6 weeks after engraftment, and decreased thereafter. SCID mice but not nude mice grafted with HT thyroid tissue produce antibodies to thyroglobulin and thyroperoxidase. Lymphocytes within intact HT thyroid grafts persist in SCID mice, and migrate to the spleen, whereas human lymphocytes do not survive in the thyroid grafts or other tissues of the nude mouse. In 6 weeks, the xenografts in nude mice became histologically normal. In contrast, xenografts from SCID mice showed more marked inflammatory changes than in the original human lesion, although the ratio of T/B cells is unchanged. This worsening of the lesion may relate to the increase in activation of the T-lymphocytes.

Pathogenesis of Autoimmune Hypothyroidism Induced by Lymphokine-Activated Killer (LAK) Cell Therapy:In VitroInhibition of Human Thyroid Function by Interleukin-2 in the Presence of Autologous Intrathyroidal Lymphocytes

Lymphokine-activated killer (LAK) cell therapy frequently results in primary hypothyroidism. To elucidate the responsible mechanism, we investigated the effects of interleukin-2 (IL-2) on thyroid function of cultured human thyroid follicles in the presence or absence of autologous thyroid-derived lymphoid cells (TDLC). Human thyroid follicles, obtained by subtotal thyroidectomy from patients with Graves' disease, were cultured in serum-free medium containing bTSH and various concentrations of human IL-2, with or without TDLC. After 5 days of culture, 125I was added, and after an additional 3 days of culture, 125I incorporated into thyroid follicles and organic 125I (125I-T4 + 125I-T3) released into the culture medium were estimated. In the absence of TDLC, IL-2 did not affect bTSH-induced thyroid function. In the presence of TDLC, however, IL-2 inhibited the bTSH-stimulated thyroid function in a concentration-dependent manner. The minimum IL-2 concentration required to inhibit thyroid function was 1 U/ml. At 100 U/ml, IL-2 inhibited thyroid function completely. IL-2 increased the concentration of IFN-gamma in the culture medium conditioned by TDLC but not by thyroid follicles. When both were cocultured, IL-2 more significantly increased the concentration of IFN-gamma to an extent sufficient for inhibiting thyroid function per se. Furthermore, the addition of anti-IFN-gamma antibody to the medium partially restored the IL-2-inhibited thyroid function. In summary, by coculturing human thyroid follicles and autologous intrathyroidal lymphocytes with IL-2, it was possible to reproduce the thyroid dysfunction associated with LAK cell therapy. Our data indicate that IL-2 inhibits thyroid function, at least partly, by stimulating production of IFN-gamma, a potent inhibitory cytokine for thyroid cells.

Reconstitution of severe combined immunodeficient mice with intrathyroidal lymphocytes of thyroid xenografts from patients with Hashimoto's thyroiditis

Reconstitution of severe combined immunodeficient mice with intrathyroidal lymphocytes of thyroid xenografts from patients with Hashimoto's thyroiditis

Immunoreactivity to Yersinia enterocolitica antigens in patients with autoimmune thyroid disease.

Recent reports have suggested that Yersinia enterocolitica proteins encoded by a 72-kilobase virulence plasmid (known as release proteins and now identified as YOP2-5) are antigens recognized specifically by patients with Graves' disease and of potential etiological importance in this disorder. To examine this hypothesis, we evaluated immune responses to YOP in patients with autoimmune thyroid disease and in normal controls. Humoral responses to Yersinia were assessed using Western blots of crude Y. enterocolitica membrane proteins, Yersinia release proteins (YOP2-5), and human thyrocyte membranes. Twenty-four of 25 Graves' and 10 of 18 Hashimoto's patients showed reactivity with the release proteins, primarily the 67-, 46-, 36-, and 25-kilodalton bands. However, 17 of 24 normal subjects also demonstrated serological reactivity to the release proteins, and the pattern of reactivity of these sera was similar to that in the thyroid patients. No correlation was noted between serological reactivity to the release proteins and thyroid hormone levels. Patients and controls with serological reactivity to YOP also showed reactivity with Yersinia membranes. In addition to the serological studies, cellular immune responses were determined by peripheral blood mononuclear cell proliferation assays. Cellular reactivity to the release proteins was present in four of five Graves' and both Hashimoto's patients tested, but also in two of six nonthyroid illness patients with serological immunity to the release proteins. Intrathyroidal lymphocytes obtained from two Graves' patients demonstrated marked proliferation in response to the release proteins. These results indicate that there is no unique pattern of serological reactivity against Yersinia membranes or the release proteins in patients with autoimmune thyroid diseases and suggest that any causal relationship between Yersinia infection and Graves' disease may be related to T-cell immunity.

No major monoclonal lymphocyte population in the thyroid of patients with Graves' disease: study of gene rearrangement by restriction fragment length polymorphism and polymerase chain reaction.

The present study aimed at determining the mono-, oligo-, or polyclonal nature of intrathyroid lymphocytes at the DNA level in patients with Graves' disease. Two techniques were used to seek monoclonal rearrangement in DNA derived from intrathyroidal lymphocytes obtained from six patients. The first was restriction fragment length polymorphism using two specific probes from the B-chain of T-cell receptor and the other from the heavy chain immunoglobulin gene; the second was polymerase chain reaction using a couple of specific primers from the variable and joining regions of heavy chain immunoglobulins. The results for the patients with Graves' disease were compared with those obtained for circulating T-and B-lymphocytes, granulocytes (negative controls), and T- and B-leukemic cells (positive controls). The results with restriction fragment length polymorphism favored a polyclonal origin for the lymphocytes in all cases, since no rearrangement was visualized. The results with polymerase chain reaction were analogous, and the technique was 10 times more sensitive in the detection of rearrangement.

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)

The SCID-hu mouse and thyroid autoimmunity: Characterization of human thyroid autoantibody secretion

Severe combined immunodeficient ( SCID) mice were injected with peripheral blood mononuclear cells (PBMC) from normal individuals and 14 out of 18 had detectable serum human (h) IgG (maximum levels providing a mean ± SEM 934 ± 213 μg/ml) and IgM (253 ± 93 μg/ml) at 3–6 weeks after transplantation. Serum human immunoglobulin levels were maximum 6–12 weeks after transplantation and declined to low levels over the subsequent 5 months. Human B cells constituted up to 10% and human T cells up to 40% of cells in the peripheral circulation and spleens of these animals 2–3 weeks after transplantation. PBMC, or intrathyroidal (IT) lymphocytes, from 6 patients with Graves' disease and high serum levels of thyroid autoantibodies were transplanted into 30 SCID mice (Graves' SCID-hu). Although serum human immunoglobulins were observed in only low amounts in the animals receiving IT lymphocytes ( n = 4), increased levels of hIgG or hIgM were more easily detectable in 19 Graves' SCID-hu mice that received PBMC. The Graves' SCID-hu mice had significantly lower mean levels of hIgG and hIgM than those observed following transplantation of normal PBMC (mean maximum 328 ± 113 and 32 ± 21 μg/ml, respectively). Six of these 19 mice had detectable human autoantibody to thyroid peroxidase (TPO, as microsomal antigen) between 3 and 8 weeks after transplantation, with titers ranging from 0.05 to 0.39 (normal SCID-hu serum <0.02 ELISA Index). No abnormal thyroid hormone (T4 and T3) levels or thyroiditis was seen when compared to normal SCID-hu mice. Immunization of reconstituted SCID mice with recombinant immunoactive human TPO antigen failed to initiate anti-TPO in normal PBMC-treated mice nor did it increase the titer of human anti-TPO in the anti-TPO positive animals. In conclusion we successfully established human thyroid autoantibody secretion in the SCID-hu mouse and characterized the transient nature of the model. Further studies will be required to achieve successful antigen presentation in this system.

Predominant intraepithelial localization of primed T cells and immunoglobulin-producing lymphocytes in Graves' disease

It has been proposed that intrathyroid lymphocytes, localized in specific anatomical sites might have distinct, pathophysiologically relevant functions in Graves' disease. However, most studies of intrathyroidal lymphocytes were restricted to two lymphocyte locations and used semiquantitative methods. Therefore we used seven anatomically different lymphoid compartments to classify and evaluate by quantitative representative methods the total intrathyroidal lymphocytic infiltration and the staining indexes for immunoglobulin-producing plasmocytes and primed T cells (CD45RO), which provide maximum help to pokeweed mitogen-stimulated immunoglobulin synthesis in 36 thyroid glands from patients with Graves' disease. We found only 3.4% of all intrathyroidal lymphocytes intraepithelially. However, only intraepithelial lymphocytes showed a significantly higher staining index for primed T cells compared with several other compartments. There was also a high staining index for immunoglobulin-producing lymphocytes in this compartment. Kappa- and lambda-positive plasmocytes were found in a polyclonal distribution (kappa:lambda = 64.1: 35.9) in all compartments. This increased incidence of CD45RO-positive T lymphocytes and of immunoglobulin-producing lymphocytes among the intraepithelial lymphocytes suggests a distinct pathophysiological function of lymphocytes in peripolesis in Graves' disease. Furthermore, there is a polyclonal intrathyroidal immunoglobulin synthesis.

CYTOFLUOROMETRIC ANALYSIS OF LYMPHOCYTE SUBSETS IN THYROID ASPIRATES FROM PATIENTS WITH AUTONOMOUSLY FUNCTIONING NODULE

A microscale method, based on two-colour dye immunolabelling and flow sorting cytofluorometry, was used to characterize lymphocyte subsets in thyroid tissue specimens obtained by fine-needle aspiration (FNA) in 21 patients with autonomously functioning thyroid nodule (AFTN) and five patients with cold thyroid nodule (CTN). Inversion of the ratio between CD4+ and CD8+ lymphocytes, due to a relative increase of CD8+ cells, was found among intrathyroidal lymphocytes in AFTN patients. The abnormal lymphocyte subset distribution was not observed in the peripheral blood of the same group of patients. In patients with CTN the lymphocyte subset distribution was normal, both in the thyroid and in the peripheral blood. In AFTN patients, a significant correlation was observed between the decrease of intrathyroidal CD4+/CD8+ ratio and the increase of plasma thyroid hormone levels. Whether the immunological abnormalities found in AFTN could play a pathogenetic role in the clinical presentation and outcome of the disease remains to be established. The FNA-applied micromethod used in this study could be extended as a routine investigation to characterize the immunogenic substrate of thyroid disorders.

Intrathyroidal Lymphocytes from Non Toxic Multinodular Goiter: No Evidence for Production of Thyroid Stimulating Antibodies

Although an autoimmune pathogenesis for non toxic goiter has been suggested, reports concerning circulating antibodies to TSH receptor structures have been conflicting. Intra thyroid lymphocytes, capable of secreting IgG, have been shown to be involved in the pathogenesis of Graves' and Hashimoto's diseases; therefore, the ability of conditioned media obtained from intra thyroid lymphocyte culture, and of IgG purified from these media, to stimulate cAMP accumulation and [3H]-Thymidine (TdR) uptake in FRTL-5 cells was investigated. The activity of IgG produced "in vitro" was compared with that of circulating IgG. Thyroid tissue samples were obtained at surgery from 21 patients with non toxic multinodular goiter (MNG), 5 patients with active Graves' disease (GD), and from 10 normal subjects, undergoing neck surgery for non-thyroidal pathology. IgG purified from media of GD lymphocyte cultures stimulated both cAMP accumulation and [3H]-TdR in 5 out of 5 cases: all of the IgG purified from control or MNG lymphocyte culture media was not active in either assay. Circulating IgG did not affect cAMP accumulation or [3H]-TdR in any of the non toxic MNG cases: controls showed no changed at all. However, both activities represented were increased by GD IgG. Conditioned media from intra thyroid lymphocyte cultures significantly inhibited basal cAMP accumulation in 7 out of the 21 non toxic MNG samples and totally abolished the response in all GD patients. [3H]-TdR was not affected by IgG of any of the controls, but it had an inhibitory effect on 8 out of 21 non toxic MNG patients, and significantly stimulated [3H]-TdR in all GD patients. In conclusion, present data demonstrate that intra thyroid lymphocytes from non toxic MNG do not produce antibodies capable of mimicking TSH actions through the adenylate cyclase cascade. Conversely, soluble factors interacting in TSH-mediated functions of FRTL-5 cells are present in conditioned media of intra thyroid lymphocytes of GD and MNG thyroid lymphocytes of GD and MNG thyroid cultures.

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.

Successful Production of Intrathyroidal Human T Cell Hybridomas: Evidence for Intact Helper T Cell Function in Graves’ Disease*

We have developed a series of human intrathyroidal T-T cell hybridomas and evaluated their phenotypic characteristics and lymphokine secretions in order to further understand the role of the T cell in Graves' disease. Mitogen-stimulated T cell blasts were generated from intrathyroidal lymphocyte preparations and fused with a hypoxanthine-, aminopterin-, and thymidine-sensitive variant of the Molt 4 human leukemia T cell line. The resulting intrathyroidal T-T cell hybridomas and T-T cell hybridomas obtained from normal peripheral blood mitogen-stimulated T cell blasts were expanded and tested for their biological function. None of the generated T cell hybridomas exhibited antigen-specific IL-2 secretion when stimulated with autologous thyrocytes, although 60% of the hybridomas expressed CD3 antigen and the T cell receptor alpha/beta heterodimer. However, 9 intrathyroidal and 11 peripheral blood T cell hybridomas secreted a factor(s) that significantly enhanced immunoglobulin G secretion in vitro (P less than 0.005, by Student-Newman-Keuls test; mean +/- SEM, 338 +/- 60% increase). In summary, we have successfully used a technique that allows the construction of T-T cell hybridomas derived from intrathyroidal T cell cultures. The data demonstrated that a predominance of helper factor-secreting T cells were available for fusion within the Graves' thyroid gland. Such observations are further evidence for intact T cell help within the thyroid gland of patients with Graves' disease.

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.

Increment in the Ta1+ cells in the peripheral blood and thyroid tissue of patients with Graves' disease.

The present study utilized the anti-Ta1 mAb to characterize the cell surface phenotypes of peripheral blood and intrathyroidal lymphocytes in patients with Graves' disease. We found an increase in PBL bearing the Ta1 Ag in untreated patients. The euthyroid patients in remission, induced by antithyroidal drugs, radioisotope therapy, and subtotal thyroidectomy, had lower percentages of Ta1+ cells than did untreated patients. An increased percentage of Ta1+ cells in untreated patients was found in both CD4+ cells and CD8+ cells. The ratio of CD4+Ta1+ cells to CD8+Ta1+ cells in untreated patients was significantly higher than that of normal subjects. There was a positive correlation between the percentage of Ta1+ cells and the level of anti-TSH receptor antibody. In this prospective study, the proportion of Ta1+ cells was decreased in parallel with the reduction in anti-TSH receptor antibody and free T3 levels. In the chronically treated patients, the proportion of Ta1+ cells in the thyroid tissue was, yet similar to that in the peripheral blood, markedly increased in comparison to that of normal subjects. In contrast to Ta1+ cells, the thyroid tissue had a significantly higher percentage of HLA-DR+ T cells than did the paired peripheral blood. The proliferative responses of the Ta1+ cell-enriched population isolated from untreated patients toward thyroglobulin and microsomal Ag were markedly higher than those in a Ta1+ cell-depleted population, but both populations were able to respond equally to PHA. These results suggest that the Ta1+ cells may include Ag-triggered memory cells that are reactive with thyroid-specific Ag. Furthermore, monitoring such cells may provide an objective measure of abnormal immunologic activity.

TSH-binding inhibitor immunoglobulin (TBII) in thyroidal venous blood and histological grade of intrathyroidal lymphocyte appearance in Graves' disease.

The aim of this study is to investigate the possibility of determining the appropriate amount of thyroid tissue to leave behind as remnant weight in subtotal thyroidectomy for Graves' disease by measuring the TBII value, and correlating the outcome to the grade of intrathyroidal lymphocyte infiltration. We therefore have investigated the levels of TBII in the thyroidal (T-TBII) and peripheral (P-TBII) venous blood, and the grade of lymphocytic infiltration and lymph follicle formation in the intrathyroidal tissue. There was no parallel relationship between the T-TBII value and the grade of lymphocytic infiltration and lymph follicle formation. There was no marked difference between the T-TBII value and the P-TBII value. It was thus not possible to use these data to determine the proper remnant weight of Graves' thyroid tissue at the time of surgery.

Phenotypic analyses and concanavalin-A-induced suppressor cell dysfunction of intrathyroidal lymphocytes from patients with Graves' disease.

The expression of phenotypic markers and Concanavalin-A-induced suppressor activity was compared among mononuclear cells isolated from thyroid glands and peripheral blood of thionamide-treated patients with hyperthyroid Graves' disease and peripheral blood from normal subjects. Intrathyroidal lymphocytes were obtained by two different methods (TG-1 and TG-2 cells), gradient centrifugation of supernatants of minced thyroid tissue and overnight culture of thyroid debris after mechanical disaggregation and enzymatic digestion, respectively. The percentages of CD3+ cells (all mature T cells) among peripheral blood and TG-1 and TG-2 cells from Graves' patients were similar, but the percentages of B1+ cells (pan B cells) among the TG-1 and TG-2 cells were markedly increased compared to that in peripheral blood. The percentages of CD4+ cells among the TG-1 and TG-2 cells were significantly less than that in peripheral blood. The percentages of CD4+2H4+ cells among CD4+ cells in TG-1 and TG-2 cells also were significantly less than that in peripheral blood. The percentage of CD4+4B4+ cells among CD4+ cells in thyroid glands was markedly higher than that in peripheral blood. The percentages of CD8+ cells and CD8+CD11b- cells (cytotoxic T cells) in thyroid glands were significantly higher than those in peripheral blood from Graves' patients and peripheral blood from normal subjects. The CD8+CD11b+ cells were subdivided into two subpopulations on the basis of CD8 antigen density. The percentage of dull CD8+CD11b+ cells (natural killer cells) among TG-2 cells was lower than that in peripheral blood, but there was no significant difference in bright CD8+CD11b+ cells (suppressor-effector T cells) between thyroid glands and peripheral blood. The percent suppression induced by Concanavalin-A in both TG-1 and TG-2 cells was significantly decreased compared with that in peripheral blood. These results suggest that impairment of suppressor cell activity and an increased number of B cells exist in thyroid glands of patients with Graves' disease compared to those in peripheral blood. It, thus, appears likely that both B cell hyperactivity and suppressor T cell dysfunction may induce excess production of autoantibodies in the thyroid glands of such patients.

Immunoglobulin and T cell antigen receptor gene arrangements indicate that the immune response in autoimmune thyroid disease is polyclonal.

To further define the degree of heterogeneity of the antibody and cellular immune responses in autoimmune thyroid disease, we used Southern blot hybridization techniques to analyze the arrangements of immunoglobulin and T cell antigen receptor genes in circulating lymphocytes and in those infiltrating the thyroid gland in nine patients with thyrotoxicosis due to Graves' disease and five patients with Hashimoto's thyroiditis. The sensitivity of these techniques was sufficient to detect a monoclonal population when there was as little as 1% clonal involvement in a mixed cell population. In the patients studied, DNA from non-T peripheral blood cells and non-T intrathyroid lymphocytes had only a germline gene pattern and no clonal nongermline rearrangements of immunoglobulin genes, as assessed using an immunoglobulin joining heavy chain (IgJH) gene probe. An analysis of the DNA from peripheral blood T cells or intrathyroidal lymphocytes revealed polyclonal gene rearrangement patterns and no clonal nongermline rearrangements of the T cell antigen receptor-beta and -gamma genes, as assessed using T constant-beta and T joining -gamma gene probes. These results indicate that the lymphocytes in peripheral blood and those infiltrating the thyroid gland in patients with autoimmune thyroid disease are of polyclonal origin.

Immunohistochemical analysis of intrathyroidal lymphocytes in Graves' disease: Evidence of activated T cells and production of interferon-γ

Previous immunohistochemical studies of the thyroid gland in Graves' disease (GD) have demonstrated that (i) lymphoid cells infiltrating the interstitium of the gland predominantly express the CD4+ (T-helper) phenotype; (ii) lymphoid cells infiltrating the epithelial compartment express predominantly the CD8+ antigen; and (iii) thyroid epithelial cells (thyrocytes) express class II histocompatibility antigens, possibly in response to endogenous production of interferon-γ (IFN-γ) by the infiltrating lymphocytes. In the present study the infiltrating lymphoid cells and thyrocytes in GD were further characterized by immunocytochemistry. Scattered infiltrating interstitial lymphocytes stained positively with antibodies directed against IFN-γ and the receptor for interleukin 2. These lymphocytes were most prominent around the periphery of lymphoid nodules. The interstitial lymphocytes predominantly expressed the CD4+ 2H4+ phenotype rather than the complementary CD4+ 4B4+ phenotype, suggesting the presence of the suppressor-inducer rather than helper-inducer T cell subset. The infiltrating lymphocytes were associated with thyrocytes expressing HLA-DR antigens, as previously reported, and also HLA-DQ antigens, but to a lesser extent. The presence of HLA-DQ may also suggest the possibility of an induced suppressor response. The intraepithelial CD8+ cells did not stain with antibodies to CD3, 2H4, 4B4, or Leu 7 and their identity remains unknown.