Accumulation of thyroid antigen-reactive T lymphocytes in the gland of patients with subacute thyroiditis.

Blood and thyroid-infiltrating lymphocytes from patients with de Quervain's subacute thyroiditis were tested in the leucocyte migration inhibition test for cell-mediated immunity (CMI) to thyroid antigen. Blood leucocytes were positive for CMI in eleven out of thirteen (85%) patients in the acute phase of the disease. In five cases tested repeatedly this reactivity disappeared after 7-11 months. Thyroid-infiltrating lymphocytes were obtained from eight patients by fine-needle aspiration biopsy. There was a relative accumulation of T lymphocytes (90 +/- 5%) in the thyroid gland as compared to lower numbers of T cells (65 +/- 5%) in the blood. When thyroid-infiltrating lymphocytes were tested for CMI to thyroid antigen, a significantly stronger inhibition was demonstrated with the infiltrating lymphocytes as compared to that of blood leucocytes. We conclude that thyroid antigen-reactive T cells accumulate in the glands of patients with subacute thyroiditis. This observation is in accordance with the presumed viral aetiology of this disorder.     

Proliferation of T8-positive cytolytic T lymphocytes in response to thyroglobulin in human autoimmune thyroiditis: analysis of cell interactions and culture requirements

These experiments were designed to analyze the involvement of T-lymphocyte subpopulations in autoimmune thyroid disorders such as Graves' Disease (GD) and Hashimoto's Disease (HD). In a first set of experiments, lymphocytes isolated from thyroid infiltrates or from peripheral blood of GD and HD patients were analyzed for the expression of various surface antigens. While HLA-DR + T cells were numerous among thyroid infiltrating T lymphocytes in both groups of patients, the proportions of T8 + cells (as defined by their reactivity with the B 9.4 monoclonal antibody specific for T8 surface molecule) were strikingly different in HD and GD. In the latter group of patients only 19% of infiltrating T cells were T8 +, whereas these cells represented approximately 50% in four HD patients. Given the previous demonstration that all T cells expressing T8 antigen are cytolytic T lymphocytes (CTL) or their precursors (CTL-P) in conjunction with the fact that lymphocytes from HD or GD patients are known to proliferate in vitro in response to human tg (Htg), we further analyzed the T-cell subset(s) responsible for in vitro proliferation to Htg. In these experiments, peripheral blood T lymphocytes purified from patients with GD or HD were cultured with 1 microgram/ml Htg and irradiated autologous T-depleted mononuclear cells as the source of antigen presenting cells (APC). The proportions of T8 + cells declined considerably during culture in GD patients, but at Days 6 to 9, T8 + cells represented as much as 51% of cultured T lymphocytes from patients with HD. Moreover, the majority of T8 + cells were medium-large size lymphoblasts. Removal of Htg at Day 6 resulted in both abrogation of proliferative responsiveness and in decreases of T8 + percentages. Further analysis of the cell interactions leading to T8 + cell proliferation in response to Htg showed that helper/inducer T cells, as defined by 5/9 antigen expression, were strictly required. Collectively, these features are reminiscent of the T-cell involvement in experimental autoimmune thyroiditis of mice and stress for the first time the potential role of CTL in tissue damage occurring in Hashimoto's thyroiditis.     

Graves' disease: phenotypic and functional analysis at the clonal level of the T-cell repertoire in peripheral blood and in thyroid

We have investigated at the clonal level the repertoire of intrathyroid and peripheral T lymphocytes in three patients with Graves' disease using a high efficiency cloning technique. Clonal efficiencies ranged from 10 to 31% for intrathyroid, and from 19 to 100% for peripheral T cells. In Graves' disease the phenotypic analysis showed similar percentages of CD3+ CD4+ CD8- and CD3+ CD4- CD8+ clones in thyroid infiltrates and peripheral blood. The functional evaluation showed similar or lower proportions of cytolytic clones in thyroid infiltrates with respect to peripheral blood. Furthermore, the proportions of intrathyroid and peripheral T-cell clones capable of releasing interleukin-2 and/or gamma-interferon in response to mitogen stimulation were similar. Finally, 44% of intrathyroid clones were neither cytolytic nor able to release IL-2 and gamma-interferon. These results are strikingly different from those obtained in Hashimoto's thyroiditis, where the large majority of intrathyroid T-cell clones are cytolytic and the proportions of clones able to release gamma-IFN are remarkably increased in thyroid infiltrates when compared to those obtained from peripheral blood. Taken together, these data suggest a different role for T lymphocytes in the pathogenesis of the two major human autoimmune thyroid diseases.     

Characterization of lymphoid cells in the thyroid of patients with Graves'' disease.

The distribution and function of lymphoid cells has been investigated in thyroid glands obtained at operation from 16 patients with Graves' disease (GD) using a peroxidase technique to enumerate total T and B lymphocytes as well as helper and suppressor T cell subsets in tissue sections. A spectrum of lymphocytic infiltration was observed and the increase from minimal numbers of immune cells in some GD thyroids to focal thyroiditis in others appeared to be due to a rise in all the lymphoid cell types analysed and was not the result of major change in any one lymphoid compartment. T cells were diffusely distributed whereas B cells tended to occur in aggregates. Small numbers of OKT6+ cells (possibly antigen presenting cells) were observed although these were less numerous than in lymphoid organs such as tonsil. Lymphoid cell suspensions prepared from the thyroid tissue of five of seven GD individuals treated pre-operatively with propranolol synthesized thyroid autoantibodies spontaneously in culture and this synthesis was decreased in the presence of pokeweed mitogen. Since the OKT8+ T cell subset has been shown to suppress immunoglobulin production by lymphocyte cultures containing mitogen, it appears that the suppressor T cells, which are readily demonstrable in GD thyroid sections, are functional. It seems unlikely, therefore, that a defect in this type of suppression is responsible for the initiation or perpetuation of the autoimmune response to thyroid antigens in GD.     

Enumeration of T lymphocytes subsets in autoimmune disease using monoclonal antibodies.

The numbers of T lymphocytes, B lymphocytes, helper and suppressor T lymphocytes were measured in peripheral blood of patients with autoimmune disease (rheumatoid arthritis, erythema nodosum, Sjögren''s disease, Wegener''s disease, idiopathic thrombocytopenia, pernicious anaemia and Hashimoto''s disease). B lymphocytes were enumerated by direct immunofluorescence and T lymphocytes by E rosette tests and by indirect immunofluorescence with OKT3.PAN Helper and suppressor T lymphocytes were determined by indirect immunofluorescence with OKT4.IND and OKT8.SUP respectively. The numbers of T lymphocytes, B lymphocytes and helper T lymphocytes in patients with autoimmune disease were normal, but the numbers of suppressor T lymphocytes were significantly lower.     

Gamma delta lymphocytes in endocrine autoimmunity: evidence of expansion in Graves' disease but not in type 1 diabetes.

Endocrine autoimmune disorders are mediated by T cell-dependent responses to organ-specific antigens, but the mechanisms initiating the process remain unknown. Lymphocytes which use the gamma delta heterodimer as T cell receptor (TCR) for antigen constitute a distinct subset of T cells whose function remains elusive. In order to investigate their possible involvement in endocrine autoimmunity we have determined the proportion of gamma delta T cells in the peripheral blood of 23 patients with type 1 (insulin-dependent) diabetes mellitus (type-1 DM) and 30 patients with autoimmune thyrotoxicosis (Graves' disease). T lymphocyte TCR expression was assessed by fluorescence-activated flow cytometry on peripheral blood mononuclear cells using MoAbs UCHT1 (CD3), TCR delta 1 (gamma delta TCR), WT31 and beta F1 (alpha beta TCR) and both the percentage of T cells expressing gamma delta and the ratio gamma delta/alpha beta were calculated. In the diabetic patients gamma delta cells were not significantly different from the control group (7.7 +/- 54% versus 8.0 +/- 5.5% of T cells, P NS). There was no relation between the proportion of gamma delta lymphocytes and the presence of islet cell antibodies (ICA) in the sera. The Graves' patients showed a tendency towards a higher proportion of gamma delta T lymphocytes than the controls (gamma delta/alpha beta ratios: 0.095 +/- 0.047 versus 0.063 +/- 0.022, P = 0.03). In 14 Graves' patients the number of gamma delta were measured in paired samples of peripheral and intrathyroidal lymphocytes, demonstrating an expansion of gamma delta within the thyroid glands (0.21 +/- 0.3 versus 0.095 +/- 0.047, P = 0.032). Immunohistochemical studies showed that gamma delta cells were scattered among the predominant alpha beta lymphocytes infiltrating the thyroid gland and that they account for 10% of intraepithelial lymphocytes. No relation was found between the increase of gamma delta lymphocytes and any clinical features.     

Antigen specific immune response potential and HLA typing of Israeli patients with thyroid autoimmune diseases (TAD).

The immune response potential to the synthetic polypeptide antigen (T,G)-A--L was studied in 35 patients with thyroid autoimmune diseases (TAD). For this purpose the ability of their antigen activated peripheral blood lymphocytes (PBL) to generate a (T,G)-A--L specific helper factor was tested. In addition, the patients were typed for their HLA determinants. The results of the study have shown that 20/35 (57%) patients responded to (T,G)-A--L, a similar proportion to that found among healthy donors that were tested as control. No significant difference was found in the rate of responses between patients with Graves' disease and Hashimoto's thyroiditis. The responses in these groups of patients were shown to be 13/22 (59%) and 7/13 (54%) respectively. HLA typing of 26 patients with TAD did not demonstrate any association of the disease or the immune response potential with any specific HLA determinant. It is proposed that unlike the general lack of regulation that we have previously observed in patients with systemic lupus erythematosus, the abnormal autoimmune reaction in TAD and probably in other organ-specific autoimmune diseases, is towards a specific organ without affecting other arms and functions of the immune system.     

Immunophenotypic and genotypic characterisation of multiple myelomas with adverse prognosis characterised by immunohistological expression of the T cell related antigen CD45RO (UCHL-1).

AIMS: To investigate whether plasma cell expression of early B cell, late B cell/preplasma cell, T cell, and myelomonocytic antigens or myeloma associated lymphocytic infiltrates correlated with prognosis in bone marrow biopsy specimens of patients with multiple myeloma. METHODS: Bone marrow biopsy specimens of 23 patients with multiple myeloma were investigated for plasma cell expression and interstitial lymphocyte expression of T cell related antigen CD45RO (UCHL-1). RESULTS: Eight patients showed plasma cell expression of CD45RO and 16 showed increased tumour infiltrating CD45RO positive lymphocytes, which were correlated with poor survival by multivariate analyses (p = 0.005 and p = 0.04, respectively). B cell antigens (MB2, CD20) but no T cell specific antigens (CD3) or T cell receptor gene rearrangements were expressed by plasma cells in CD45RO positive myelomas. Of 16 patients with myeloma who had increased tumour infiltrating CD45RO positive lymphocytes, four had interstitial lymphocyte expression of B cell antigens and two had interstitial lymphocyte expression of the T cell specific antigen CD3. CONCLUSIONS: The recognition of plasma cell expression of CD45RO and increased interstitial CD45RO lymphocytes in bone marrow biopsy specimens of patients with multiple myeloma is an adverse prognostic finding not indicative of an aberrant T cell phenotype or genotype; it is consistent with B cell/pre-plasma cell antigen expression by myeloma cells and their lymphocytic precursors.     

Vasculitis in lichen sclerosus: an under recognized feature?

AIMS: To analyse 90 vulvar and 72 penile cases of lichen sclerosus (LS) on haematoxylin and eosin sections for vascular changes and the vascular infiltrates immunohistochemically with antibodies to T cells, B cells and antigen-presenting dendritic cells. LS is a skin disease of presumed autoimmune origin. Autoimmune diseases are mediated by lymphocytes which occasionally produce a lymphocytic vasculitis. METHODS AND RESULTS: Three types of lymphocytic infiltrates were identified: (i) perivascular lymphocytic infiltrates without damage to vessel walls; (ii) lymphocytic vasculitis in three forms: (a) concentric lymphohistiocytic infiltrates with lamination of the adventitia by basement membrane material which was typical for penile LS; (b) lymphocytic vasculitis with dense perivascular lymphocytic cuffing with occasional fibrin deposition in vessel walls and subendothelial lymphocyte infiltration, quite common in vulvar LS; and (c) intramural lymphocytic infiltrates in large muscular vessels; (iii) leukocytoclastic vasculitis in LS was exceptionally rare. In lymphocytic vasculitis, CD20+ B cells, CD4+ T cells and dendritic cells were the principal infiltrating cells. CONCLUSIONS: Dendritic cells capture (foreign) antigens after entry into the affected tissues and initiate immune responses acting as a matrix on which antigen-specific T and B cells interact. The described vascular features are indicative of antigen-mediated vasculitic changes in LS.     

Induction of suppressor cells by Mycobacterium paratuberculosis antigen in inflammatory bowel disease.

We studied the M. paratuberculosis-induced proliferation and suppressor cell generation by peripheral blood lymphocytes from patients with inflammatory bowel disease. Peripheral blood lymphocytes were separated from 33 patients with Crohn's disease, 18 with ulcerative colitis, nine with other intestinal diseases, and five with autoimmune disorders. Proliferation of peripheral blood lymphocytes from normal individuals in response to 10 micrograms/ml of M. paratuberculosis antigen was reduced by depletion of CD4+ T cells. The ability of M. paratuberculosis antigen to suppress concanavalin A-induced proliferation (expressed as a percentage suppression) was reduced by depletion of CD8+ T cells. This suppression was the same whether peripheral blood lymphocytes were from normal individuals, patients with intestinal diseases other than inflammatory bowel disease, or patients with autoimmune disorders (47 +/- 14%, 44 +/- 24%, and 30 +/- 26%, respectively). In contrast, the suppression induced by M. paratuberculosis for patients with Crohn's disease and ulcerative colitis (66 +/- 22% and 67 +/- 22%) was much greater than that for normal individuals (P less than 0.001). In particular, lymphocytes from patients with active Crohn's disease demonstrated little proliferation in response to this antigen but marked suppressor activity (79 +/- 13%). How the immunomodulatory effects of this antigen relate to the pathogenesis of the inflammatory bowel diseases remains to be determined.     

Hashimoto's thyroiditis lacks detectable clonal immunoglobulin and T cell receptor gene rearrangements

The development of B cell lymphoma, predominantly of the large-cell type, in patients with autoimmune diseases such as Hashimoto's thyroiditis or Sjogren's syndrome is well known. In Sjogren's syndrome, it has been recently shown that the benign-appearing lymphocytic infiltrates of the lymphoepithelial lesions in the salivary glands have clonal rearrangements of immunoglobulin genes in their DNA, even in the absence of malignant lymphoma. To investigate whether a similar situation occurs in Hashimoto's thyroiditis, we studied the thyroid glands from four patients with this disease. In all four cases, there was a benign-appearing lymphocytic infiltrate in the thyroid, with eosinophilic changes in the Hurthle cells. In immunologic studies, we determined that the lymphocytes were polyclonal in each case. We extracted DNA from the frozen tissue blocks of these four patients and analyzed it by molecular hybridization for the presence of clonal immunoglobulin (IgH, kappa, and lambda) and T cell receptor beta chain gene rearrangements, and detected none in any case. Therefore, we conclude that the lymphocytes in Hashimoto's thyroiditis are immunologically and immunogenetically polyclonal proliferations of cells, and that the initial lesion of Hashimoto's thyroiditis does not contain a detectable clone of cells that may eventually develop into malignant lymphoma.     

The effect of hydrocortisone on the incorporation of tritiated thymidine by human blood lymphocytes cultured with phytohaemagglutinin and pokeweed mitogen

Leucocyte migration inhibition tests (LMT) with rat and human liver mitochondria are reported in forty-nine thyroid patients and forty-seven healthy controls. Whereas normal subjects and colloid goitre cases were inactive in this test, patients with autoimmune thyroiditis and thyrotoxicosis gave positive mitochondrial reactions which paralleled the organ-specific thyroid microsomal LMT obtained in the same patients and were not species dependent. The active antigen may be in the inner membranes of the particles.

As with thyroid microsomes, intense inhibition with mitochondria was seen in the hypercellular variant of Hashimoto goitre characterized serologically by low or absent thyroglobulin antibodies, and the lowest LMT values occurred in the rare cases showing poor response to thyroxine therapy. An inverse correlation was found between mitochondrial LMT and thyroglobulin antibody titres. Surprisingly, weak LMT was also found in four thyroid patients who happened to have mitochondrial antibodies in the serum in addition to the usual thyroidspecific reactivities. The mitochondrial LMT appears to be of widespread occurrence in autoimmune diseases and also develops following tissue injury. Its possible significance in relation to cellular immunity, cell destruction and the inflammatory response is discussed.

     

HLA class II antigen expression and the autoimmune thyroid response in patients with benign and malignant thyroid tumors

To further understand the relationship between the immune system and the neoplastic human thyroid cell we investigated the degree of intrathyroidal lymphocytic infiltration and thyroid HLA class II expression in 17 patients with thyroid tumors. In another 60 thyroid tumor patients the association of thyroidal lymphocytic infiltration with thyroid autoantibody production was analyzed. In total 117 thyroid tissues were examined including tissue obtained at autopsy (n = 28), fetal thyroid tissue (n = 4), thyroid samples obtained from areas distant from benign follicular adenomas (n = 5), and 80 abnormal thyroids including patients with benign (n = 53) or malignant (n = 24) thyroid tumors and Hashimoto's thyroiditis (n = 3). Normal adult and fetal thyroid tissue had no significant lymphocytic infiltration and no detectable HLA-DR, -DP, or -DQ antigens on their thyroid follicular epithelial cells. The degree of lymphocytic infiltration in the nonneoplastic thyroid tissue of thyroid glands with benign and malignant thyroid tumors varied considerably and correlated with the presence and titer of serum thyroid autoantibodies measured by sensitive ELISA techniques. However, all but one of the benign follicular adenomas had thyroid cells negative for HLA class II determinants despite the presence of infiltrating lymphocytes, while 7 of 10 thyroid carcinomas expressed class II antigen (principally HLA-DR) even when only minor degrees of lymphocytic infiltration were present. These data indicate a correlation between lymphocytic infiltrates and serum thyroid autoantibody titers but the relationship with HLA class II expression is more complex. Since we have previously shown that HLA class II antigen expression can be induced by local interferon-gamma secretion, presumably from activated T cells, we conclude that estimates of simple thyroid lymphocytic infiltration and serum autoantibody secretion do not correlate with the degree of intrathyroidal T-cell activation. Furthermore, our observation of increased expression of HLA class II antigens in thyroid cancer suggests considerable cellular heterogeneity in susceptibility to HLA class II antigen induction in human thyroid disease.     

Two different types of sialoadenitis in the NOD- and MRL/lpr mouse models for Sjögren's syndrome: a differential role for dendritic cells in the initiation of sialoadenitis?

Sj?gren's syndrome is an autoimmune disease that primarily affects the salivary and lacrimal glands. In these glands, focal lymphocytic infiltrates develop. Little is known about the initiation of this autoimmune disease. Antigen-presenting cells (APC) such as dendritic cells (DC) can play a role in the initiation of autoimmunity. To date, no data on the presence of DC in Sj?gren's syndrome are available. Several mouse strains, the nonobese diabetic (NOD) and the MRL/Ipr mouse, can be used as models for Sj?gren's syndrome. We compared the development of sialoadenitis in the submandibular glands (SMG) of NOD and MRL/Ipr mice with particular focus on the presence of APC. DC, macrophages, T cells, and B cells in the SMG were studied by means of immunohistochemistry, after which positively stained cells were quantified. NOD-severe combined immunodeficiency (SCID) mice were used to study the presence of APC in the SMG in the absence of lymphocytes. Before lymphocytic infiltration, increased numbers of DC were detected in the SMG of NOD mice compared with those numbers in control mice and MRL/Ipr mice, which suggests that DC play a role in the initiation of sialoadenitis in NOD mice. In the SMG of NOD mice, lymphocytic infiltrates organized in time. In MRL/Ipr mice, however, lymphocytic infiltrates were already organized at the time of appearance. This organization was lost over time. In conclusion, two types of sialoadenitis are described in two mouse models for Sj?gren's syndrome. Differences exist with regard to early events that may lead to the development of sialoadenitis and to the composition and organization of inflammatory infiltrates. It is possible that different types of sialoadenitis also exist in humans and that the pathogenetic process in both the early and late phases of the autoimmune reaction differs among patients.     

Evaluation of T and B lymphocytes in liver infiltrates of patients with chronic active hepatitis.

The proportions of T and B lymphocytes in the liver infiltrates of 23 patients with chronic active hepatitis have been determined. The results were compared with the values obtained from peripheral blood and with the presence of HB virus markers and alpha-fetoprotein in liver tissue. A group of patients with chronic liver disease other than chronic active hepatitis were studied as controls. In chronic active hepatitis the percentage of hepatic T cells was 49 +/- 8 SD (control patients 61 +/- 8) (P less than 0.01), whereas the percentage of B cells was 40 +/- 10 (control patients 18 +/- 8) (P less than 0.01). No correlation was observed between hepatic T and B cells and the presence of HB virus. The numbers of T cells in liver tissue was significantly higher, the numbers of B cells lower, in patients whose biopsies were positive for alpha-fetoprotein than in those whose biopsies were negative. In peripheral blood, only the patients with chronic active hepatitis and established cirrhosis presented lower absolute values of T cells, whereas surface immunoglobulin-positive lymphocytes were within the normal range.     

Phenotype analysis of tumour-infiltrating lymphocytes and lymphocytes in peripheral blood in patients with renal carcinoma

INTRODUCTION: When checking tumour growth, a number of observations indicate that the immune system plays a significant role in patients with renal cell carcinoma (RCC). Infiltration by lymphocytes (tumour infiltrating lymphocytes, TILs) is more prevalent in RCC than any other tumours. T lymphocytes are the dominant population of TIL cells. Views concerning the role of T lymphocytic subpopulations, B lymphocytes and NK cells in an anti-tumour response are not established. AIM: The aim is to determine the phenotype and activation of T and B lymphocytic subpopulations and NK cells and to compare their representation in tumour stroma and peripheral blood lymphocytes (PBL) in patients with RCC. MATERIAL AND METHODS: Samples of peripheral blood taken from the cubital and renal veins and tumour stroma cells were obtained from 44 patients in the course of their surgeries carried out due to primary RCC. TILs were isolated from mechanically disintegrated tumour tissue. Immunophenotype multiparametric analysis of PBL and TILs was carried out. Their surface and activation characteristics were determined by means of flow cytometer. RESULTS: CD3+ T lymphocytes (69.7%) were the main population of TILs. The number of CD3+/CD8+ T lymphocytes was significantly higher in TILs, 42.6% (p < 0.01), while CD4+ T lymphocytes were the majority population in peripheral blood, 41.35% (p < 0.001). The representation of CD3+/69+ T lymphocytes was significantly higher in TILs, 32.9%, compared to PBL (p < 0.001). On the contrary, the numbers of CD3+/CD25+, CD8+/57+ and CD4+/RA+ (naive CD4+ T lymphocytes) were higher in PBL (p < 0.001). The differences in representation of (CD3-/16+56+) NK cells and CD3+/DR+ T cells in TILs and PBL were not significant. CONCLUSION: The above-mentioned results prove that the characteristics and intensity of anti-tumour responses are different in compared compartments (tumour/PBL). CD3+/CD8+ T lymphocytes are the dominant lymphocytic population of TILs. The knowledge of the phenotype and functions of effector cells, which are responsible for anti-tumour response, are the basic precondition for understanding the anti-tumour immune response and the cause of its failure.     

In vivo activated cytotoxic T cells in the thyroid infiltrate of patients with Hashimoto''s thyroiditis.

High proportions of T8+ cells with inverted T4/T8 ratio were found in freshly isolated thyroid lymphocytes from patients with Hashimoto's thyroiditis. In addition, about one third of thyroid infiltrating cells expressed the TAC antigen, whereas in patient peripheral blood (PB) or normal lymphocytes from PB or lymphoid organs the percentage of TAC-positive cells was consistently lower than 10%. Following negative selection with OKT4 or OKT8 monoclonal antibodies and complement, TAC+ T cells were enriched in the T8+ cell population. Thyroid infiltrating T cells from two patients underwent two different cloning procedures. In the first, single T cells were initially activated with phytohaemagglutinin (PHA) and interleukin 2 (IL-2), in the other with recombinant IL-2 (rIL-2) alone. The majority of T cell clones obtained by initial PHA-stimulation (55-65%) had the T8+ phenotype, but the frequency of T8+ clones obtained by stimulating T cells with rIL-2 alone was even higher (78 & 71%, respectively). The majority of T8+ clones elicited by PHA (35/37 & 36/38) and all the T8+ clones (36/36 & 22/22) obtained from thyroid infiltrates with initial stimulation by rIL-2 displayed cytolytic activity. Most of cytolytic T8+ clones obtained from thyroid infiltrates with both cloning procedures, displayed NK activity against human K562 and MOLT-4 target cells, but not against a NK-resistant target, such as Raji cells. These data suggest that in Hashimoto's disease a considerable proportion of thyroid infiltrating T cells are in vivo activated T8+ cytolytic T cells with NK activity, which may be of importance in determining or maintaining the tissue damage of the target gland.     

Periductal lymphocytic infiltrates in salivary glands in myasthenia gravis patients lacking Sjögren''s syndrome.

In eight of eleven patients with clinical and serological evidence of myasthenia gravis (MG), immunohistological analysis of biopsies from labial salivary glands (LSG) showed focal periductal lymphocytic infiltrates, mainly composed of anti-Leu 3a+ T helper lymphocytes, a finding usually regarded as indicative for Sj?gren's syndrome (SS). None of the patients could however, according to functional criteria, be considered as having SS. This study thus indicates that lymphocytic infiltrates in LSG can be seen in MG, which has been thought of as an organspecific autoimmune disease with symptoms and signs confined to striated muscles.     

Thyroid autoantibody synthesis by lymphocytes from different lymphoid organs: fractionation of B cells on density gradients

Lymphocytes from thymus, blood, lymph nodes and thyroid tissue of patients with autoimmune thyroid disease have been assessed for their ability to synthesize thyroid autoantibodies spontaneously or following stimulation by Pokeweed mitogen (PWM). Blood and thymic lymphocytes synthesized IgG and microsomal or thyroglobulin antibodies of IgG class in response to PWM (and were therefore probably B-memory cells), while thyroid lymphocytes frequently secreted autoantibodies spontaneously. Lymph node lymphocytes resembled blood lymphocytes in terms of increased production of IgG in response to PWM; however, spontaneous secretion of thyroid autoantibodies was observed in some lymph node suspensions, and the magnitude of the increment in thyroid autoantibodies synthesized in response to PWM was lower than that observed for blood lymphocytes. Fractionation of B-cell enriched populations on density gradients and subsequent incubation of the fractions with T cells and PWM demonstrated that, whereas blood B cells capable of synthesizing autoantibody were found in both medium and low density fractions, lymph node precursors of thyroid autoantibody-secreting cells were associated almost exclusively with the light fractions. The presence in lymph nodes of small numbers of low density B cells, compared with a much higher proportion of the heterogeneous population capable of secreting IgG, could account for the discrepancy between the IgG and autoantibody response to PWM. Further, it seems likely that the density difference in the autoantibody precursor population of lymph nodes and blood is related to the difference in the state of activation of B cells in these lymphoid organs.     

Enhanced production of gamma-interferon by thyroid-derived T cell clones from patients with Hashimoto''s thyroiditis.

T lymphocytes from thyroid infiltrate and peripheral blood (PB) of four patients with Hashimoto's thyroiditis (HT) were analysed at clonal level for their ability to secrete interleukin 2 (IL-2) and gamma-interferon (gamma-IFN). As controls, T cell clones from PB of four normal donors and from spleen of two trauma victims were used. While no abnormality was found in the capacity to produce IL-2, the proportion of gamma-IFN-producing (IFN-P) T cell clones derived from HT infiltrates was significantly higher (P less than 0.0005) than that of IFN-P clones derived from normal or patient PB. Most of CD4+ and CD8+ IFN-P clones from thyroid infiltrates, as well as a proportion of CD4+ PB-derived clones of patients with HT, released higher amounts of gamma-IFN than control clones. A relationship could be demonstrated between high gamma-IFN production and natural killer (NK) activity in T cell clones from thyroid and PB of HT patients. In fact, the percentage of IFN-P clones with NK potential (NK+) was remarkably higher (P less than 0.0005) in thyroid infiltrates than in normal spleen or PB. The proportion of IFN-P NK+ clones from patient PB was also significantly increased (P less than 0.02) but, unlike thyroid-derived clones in which the majority of IFN-P NK+ clones were CD8+, most PB-derived IFN-P NK+ clones from the same patients expressed the CD4+ phenotype. Almost all thyroid NK+ clones could be triggered to produce more gamma-IFN, while gamma-IFN synthesis by NK-negative thyroid clones was comparable to that of control clones. In view of the multiple effects ascribed to gamma-IFN in the cascade of events leading to immune responses, the abnormal potential to gamma-IFN secretion shown by intrathyroidal T lymphocytes may be of importance in the pathogenesis of autoimmune thyroiditis.