[DREAM Study for prevention of diabetes. What conclusions may we draw?].
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Clinical Trials as Topic↗
Biomedical subjects
Jochen Seissler
Publications and source records attributed to Jochen Seissler.
Autoimmune diagnostics in diabetes mellitus.
Type 1 diabetes results from a specific destruction of the insulin-producing beta-cells of the pancreas. The disease is characterized by the appearance of specific autoantibodies against islet cell antigens. Autoantibodies to insulin, glutamic acid decarboxylase, tyrosine phosphatase IA-2 and cytoplasmic islet cell antibodies are useful markers for the differential diagnosis of type 1 diabetes when clinical and metabolic criteria alone do not allow definite classification. Autoimmune diagnostics is of particular importance in adults to discriminate between type 1 and type 2 diabetes and to assess the diagnosis of latent autoimmune diabetes in adults.
Adult↗
Systemic monocyte chemoattractant protein-1 concentrations are independent of type 2 diabetes or parameters of obesity: results from the Cooperative Health Research in the Region of Augsburg Survey S4 (KORA S4).
OBJECTIVE: Data on the relevance of monocyte chemoattractant protein (MCP)-1 in the pathophysiology of type 2 diabetes (T2D) and obesity are inconsistent. Since MCP-1 is produced by adipocytes and has been postulated to be involved in macrophage infiltration into adipose tissue, we wanted to test whether serum MCP-1 levels were correlated with T2D or obesity. DESIGN AND METHODS: Out of 1653 individuals aged 55 to 74 years participating in the population-based KORA Survey S4 (KORA/Cooperative Health Research in the Region of Augsburg) in Southern Germany, 236 patients with T2D, 242 subjects with impaired glucose tolerance and 244 normoglycaemic controls matched for age and sex were analysed for circulating MCP-1 concentrations. RESULTS: MCP-1 serum concentrations were not associated with impaired glucose tolerance, type 2 diabetes or several parameters of obesity. Moreover, systemic MCP-1 levels were not significantly correlated with all but one (fasting triglycerides) of the biochemical markers tested. CONCLUSIONS: Our data indicate that MCP-1 levels are not associated with T2D and that the contribution of fat mass to systemic MCP-1 protein might be low, suggesting that the possible local pathogenic role of MCP-1 may not be reflected by increased systemic levels of MCP-1.
Aged↗
A promoter polymorphism of the CYP27B1 gene is associated with Addison's disease, Hashimoto's thyroiditis, Graves' disease and type 1 diabetes mellitus in Germans.
BACKGROUND: CYP27B1 hydroxylase catalyzes the conversion of 25 hydroxyvitamin D(3) (25OHD(3)) to 1,25(OH)(2)D(3), the most active natural vitamin D metabolite, which plays a role in the regulation of immunity and cell proliferation. We therefore investigated two single nucleotide polymorphisms in the CYP27B1 hydroxylase gene for an association with Addison's disease, Hashimoto's thyroiditis, Graves' disease and type 1 diabetes mellitus. METHODS: Patients with Addison's disease (n=124), Hashimoto's thyroiditis (n=139), Graves' disease (n=334), type 1 diabetes mellitus (n=252) and healthy controls (n=320) were genotyped for the promoter (-1260) C/A polymorphism and for the intron 6 (+2838) C/T polymorphism of the CYP27B1 gene. Patients and controls were compared using genotype-wise and allele-wise X(2) testing. RESULTS: A significant association was found between allelic variation of the promoter (-1260) C/A polymorphism and Addison's disease, Hashimoto's thyroiditis, Graves' disease and type 1 diabetes mellitus (P=0.0062, P=0.0173, P=0.0094 and P=0.0028 respectively). Significant differences were also observed for the intron 6 (+2838) C/T polymorphism (P=0.0058) in Hashimoto's thyroiditis but not for the other autoimmune endocrine diseases. CONCLUSIONS: The CYP27B1 promoter (-1260) C/A polymorphism appears to be associated with endocrine autoimmune diseases but the CYP27B1 intron 6 (+2838) C/T polymorphism appears to be associated only with Hashimoto's thyroiditis. These results imply a regulatory difference of the CYP27B1 hydroxylase to predispose to endocrine autoimmunity.
25-Hydroxyvitamin D3 1-alpha-Hydroxylase↗
Dendritic cell-based immunotherapy in thyroid malignancies.
A new approach for anti-tumor immunotherapy is to use dendritic cells (DCs) as adjuvants in order to actively immunize cancer patients with antigens specifically expressed in tumor cells. DCs possess a unique capacity to effectively activate CD4+ T helper cells and CD8+ cytotoxic T cells. During the last years, several clinical trials in various malignancies demonstrated that immunizations with tumor antigen pulsed DCs could break the tolerance of the immune system against antigens expressed by the tumor cells resulting in partial or complete remission in some cases. This review describes the most important findings on the interaction between DCs and T cells as well as natural killer cells and summarizes recent data on DC vaccination of endocrine and non-endocrine malignancies. The results from current pilot studies suggest that DC vaccination may represent a promising strategy for the development of an anti-cancer vaccine to treat chemotherapy and radioresistant endocrine malignancies.
Animals↗
An association of autoantibody status and serum cytokine levels in type 1 diabetes.
At onset of type 1 diabetes, the islet autoantibody status of patients has been reported to predict progression of the disease. We therefore tested the hypothesis that the systemic immunoregulatory balance, as defined by levels of circulating cytokines and chemokines, is associated with islet autoantibody status. In 50 patients with recent-onset type 1 diabetes, antibodies to GAD and insulinoma-associated antigen 2 (IA-2) were analyzed by radioimmunoassay; cytoplasmic islet cell antibodies were determined by indirect immunofluorescence. Cytokine and chemokine concentrations were measured by rigidly evaluated double antibody enzyme-linked immunosorbent assay. Of four classically defined Th1/Th2 cytokines (gamma-interferon, interleukin [IL]-5, IL-10, IL-13), none showed an association with multiple autoantibody positivity. Of six mediators mainly produced by innate immunity cells, three were associated with multiple autoantibody status (IL-18 increased, MIF and MCP-1 decreased) and three were unaffected (IL-12, MIP-1beta, IP-10). GAD and/or IA-2 antibody titers negatively correlated with systemic concentrations of MIF, MIP-1beta, and IL-12. Combining the data of several cytokine and chemokine levels made it possible to predict islet antibody positivity in individual patients with 85% sensitivity and 94% specificity. These data suggest a close association of islet antibody status with systemic immunoregulation in type 1 diabetes.
Adolescent↗
[Human insulin in type I diabetes and shock].
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Animals↗
Calcitonin-specific antitumor immunity in medullary thyroid carcinoma following dendritic cell vaccination.
In this study, we investigated the immune response following immunotherapy with calcitonin-pulsed dendritic cells (DC) in 7 patients with metastasized medullary thyroid carcinoma. After immunization with 1-5 x 10(6) autologous DC, significant calcitonin-specific T cell proliferation was detectable in 3 patients. Measurement of cytokine release from T lymphocytes demonstrated high post-treatment interferon-gamma (IFN-gamma) secretion after stimulation with calcitonin in 5 patients, one of whom experienced significant tumor regression. In contrast, antigen-specific interleukin-4 (IL-4) production was only slightly increased in 4 patients. All 7 patients developed a strong delayed-type hypersensitivity (DTH) skin reaction, which was confirmed to be mediated by infiltrating CD4+ T-helper cells and CD8+ cytotoxic T cells in all 3 patients who underwent skin biopsy. This is the first study to show that a polypeptide hormone can be used to develop a DC vaccination strategy for the immunotherapy of highly malignant endocrine cancers.
Adult↗
Are we ready to predict and prevent endocrine/organ specific autoimmune diseases?
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Animals↗
Preliminary evidence that an endogenous retroviral long-terminal repeat (LTR13) at the HLA-DQB1 gene locus confers susceptibility to Addison's disease.
OBJECTIVE: Addison's disease is associated with particular haplotypes of the human leucocyte antigen (HLA) region [DQA1*0501-DQB1*0201 (DQ2) and DQA1*0301-DQB1*0302 (DQ8)]. This locus harbours several human endogenous retroviral (HERV) long-terminal repeats (LTR). LTRs within the HLA region have been shown to confer additional susceptibility to type 1 diabetes and rheumatoid arthritis. DESIGN: We investigated the role of LTR3 and LTR13, both of which are located adjacent to the DQB1 gene, in Addison's disease. PATIENTS: Eighty-seven patients and 160 controls were genotyped for HLA-DQA, -DQB, and the presence or absence of LTR3 and LTR13. RESULTS: Significantly more patients' HLA alleles than those of controls carried the LTR13 insertion (19.0% vs. 10.6%, P = 0.0143), whereas there was only a trend for LTR3 (allele-wise chi-squared test: P = 0.0941). Both, LTR3 and LTR13 are in strong linkage disequilibrium with DQ8, which itself was significantly more frequent in patients than in controls (29.9% vs. 15.0%, P = 0.0089). However, significantly more alleles of DQ8+ patients than of DQ8+ controls carried the LTR13 insertion (44.2% vs. 18.8%, P = 0.0119), whereas we did not observe any difference for LTR3 in the DQ8+ subset (30.5 vs. 23.1%, P = 0.9416). CONCLUSIONS: We have found preliminary evidence that the endogenous retroviral element DQ-LTR13, but not LTR3, is associated with Addison's disease. LTR13 appears to enhance HLA-DQ8 mediated disease risk. This retroviral insertion therefore might represent a novel susceptibility factor in Addison's disease, but these findings need to be confirmed in a larger data set.
Addison Disease↗
Effect of proinflammatory cytokines on gene expression of the diabetes-associated autoantigen IA-2 in INS-1 cells.
Cytokines released from activated antigen-presenting cells and T-lymphocytes are crucially involved in the pathogenesis of type 1 diabetes. Previous studies have shown that proinflammatory cytokines play an important role in the induction of autoimmunity and beta-cell damage. Inhibition of insulin expression has been described, but their effects on other major target autoantigens, such as the tyrosine phosphatase-like protein IA-2, is not known. In the present study, we established sensitive real-time RT-PCR to measure IA-2, insulin, and inducible nitric oxide (NO) synthase (iNOS) mRNA expression. Rat insulinoma INS-1 cells were stimulated with IL-1beta, TNF-alpha, interferon (IFN)-gamma, and IL-2 as well as with two combinations of these cytokines (C1: IL-1beta + TNF-alpha + IFN-gamma; C2: TNF-alpha + IFN-gamma). Treatment with IL-1beta, TNF-alpha, or IFN-gamma alone caused a significant down-regulation of IA-2 and insulin mRNA levels in a time and dose-dependent manner, whereas IL-2 had no effect. Exposure to cytokine combinations strongly potentiates the inhibitory effects. Incubation of cells with C1 and C2 for 24 h induces a significant inhibition of IA-2 mRNA levels by 78% and 58%, respectively. Under these conditions, an up to 5 x 10(4)-fold increase of iNOS gene expression was observed. The hypothesis that the formation of NO is involved in IA-2 regulation was confirmed by the finding that the coincubation of C1 with 4 mM L-N(G)-monomethyL-L-arginine, an inhibitor of the iNOS, partly reversed the down-regulation of IA-2. Further, incubation with the synthetic NO-donor S-nitroso-N-acetyl-D-L-penicillamine significantly decreased IA-2 mRNA level to 51% of basal levels. In conclusion, we have demonstrated for the first time that IL-1beta, TNF-alpha, and IFN-gamma exert a strong inhibitory effect on expression of the diabetes autoantigen IA-2. The action of IL-1beta may be partly mediated by the activation of the NO pathway.
Animals↗
Vitamin D receptor genotype is associated with Addison's disease.
OBJECTIVE: Autoimmune Addison's disease is a rare disorder which results from the T cell-mediated destruction of adrenocortical cells. A number of genetic susceptibility markers are shared by Addison's disease, type 1 diabetes, Graves' disease and Hashimoto's thyroiditis. The vitamin D endocrine system has been shown to influence immune regulation. Variants of the nuclear vitamin D receptor (VDR) gene were found to be associated with type 1 diabetes and thyroid autoimmunity amongst others. We therefore investigated the role of VDR polymorphisms in Addison's disease. DESIGN AND METHODS: Patients (n=95) and controls (n=220) were genotyped for VDR polymorphisms FokI, BsmI, ApaI and TaqI. RESULTS: The 'ff' (13.7% vs 5.5%; P=0.0243; odds ratio = 2.75) and the 'tt' (28.4% vs 14.1%; P=0.0043; odds ratio = 2.42) genotypes were significantly more frequent in patients than in controls. Furthermore, the BsmI genotype distribution differed significantly between patients and controls (chi(2)=6.5016 (2 d.f.) P=0.0387). CONCLUSIONS: These data suggest that the VDR genotype is associated with Addison's disease. The mechanisms by which distinct receptor variants might confer disease susceptibility remain to be elucidated.
Addison Disease↗
Different regulated expression of the tyrosine phosphatase-like proteins IA-2 and phogrin by glucose and insulin in pancreatic islets: relationship to development of insulin secretory responses in early life.
IA-2 and phogrin are tyrosine phosphatase-like proteins that may mediate interactions between secretory granules and cytoskeleton in islets and neuroendocrine tissues. We investigated factors that regulate IA-2 and phogrin expression and their relationship to maturation of insulin secretory responses that occur after birth. Islet content of IA-2, but not phogrin, increased during the first 10 days of life in rats, when insulin secretion in response to glucose increased to adult levels. In cultured 5-day-old rat islets, IA-2 protein and mRNA was increased by glucose and agents that potentiate insulin secretion by the cAMP pathway. Addition of insulin increased IA-2 protein levels and insulin biosynthesis without affecting IA-2 mRNA. Blocking insulin secretion with diazoxide or insulin action with insulin receptor antibodies inhibited glucose-induced increases in IA-2 protein, but not those of mRNA. Phogrin expression was unchanged by all agents. Thus, IA-2 is regulated at the mRNA level by glucose and elevated cAMP, whereas locally secreted insulin modulates IA-2 protein levels by stimulating biosynthesis. In contrast, phogrin expression is insensitive to factors that modify beta-cell function. These results demonstrate differential regulation of two closely related secretory granule components and identify IA-2 as a granule membrane protein subject to autocrine regulation by insulin.
Age Factors↗
IGF-1, IGFBP-3, and cancer risk.
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Acromegaly↗
Dendritic cell vaccination: new hope for the treatment of metastasized endocrine malignancies.
Dendritic cells (DCs) are antigen-presenting cells that are involved in the induction of primary immune responses. The unique ability of DCs to activate naive and memory CD4+ and CD8+ T cells suggests that they could be used for the induction of a specific antitumour immunity. In the past few years, several in vitro and in vivo studies in rodents and humans have demonstrated that immunizations with DCs pulsed with tumour antigens result in protective immunity and rejection of established tumours in various malignancies. Here, we focus on recent results of how DCs regulate immune responses that are important for generating antitumour cytotoxic T cells, and summarize clinical vaccination trials for the treatment of endocrine and nonendocrine carcinomas. Preliminary results suggest that DC vaccines might be novel tools for antitumour immunotherapies to treat chemotherapy-resistant and radioresistant endocrine cancers, such as metastasized medullary thyroid carcinomas and other neuroendocrine carcinomas.
Animals↗