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Query: UMLS:C0011854 (type 1 diabetes)
 20,749 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The pathogenesis of type 1 diabetes involves autoimmune processes directed against the pancreatic beta-cells. The etiology is not known, but circumstantial evidence suggests a connection between virus infection and development of the disease. Therefore, because the interferon-(IFN) dependent 2',5'-oligoadenylate (2-5A) synthetase system constitutes an important part of the nonspecific immune defense against viral infections, the activity of the enzyme was examined in islets of Langerhans, RIN cells, and GH3 cells. First, the 2-5A synthetase was expressed constitutively in all cell types and, second, all cells were sensitive to stimulation with IFN-alpha. The 2-5A synthetase activity induced by 1,000 U/ml of IFN-alpha increased by 400% in pancreatic islets and by more than 1000% in GH3 and RIN cells. However, the IFN-alpha concentration needed to induce half-maximal 2-5A synthetase activity was nearly the same in the three cell types (i.e., ranging from 59 to 66 U/ml IFN-alpha). The 2-5A synthetase present in islets and RIN cells was highly sensitive to poly (I:C). In pancreatic islets and RIN cells, the 2-5A synthetase enzyme generated dimers and trimers of 2',5'-oligoadenylates. Furthermore, exposure of RIN cells to IFN-alpha showed an increase in MHC class I expression already at 5 U/ml and maximal expression at about 200 U/ml IFN-alpha. The examined endocrine cells express the 2-5A synthetase enzyme as well as MHC class I antigen constitutively, but also by stimulation with IFN in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Interferon stimulates the expression of 2',5'-oligoadenylate synthetase and MHC class I antigens in insulin-producing cells. 172 88

Neopterin is specifically produced by interferon-activated macrophages, and it may be considered a marker of cellular immunity. In 40 newly diagnosed and 38 longer standing type 1 (insulin-dependent) diabetics the relationship between urinary neopterin levels and islet cell antibodies (ICA) was investigated. Raised urinary neopterin levels were found in 30 ICA positive (mean +/- SD: 729.8 +/- 602.1 mumol/mol creatinine, p = 0.0001) and 10 ICA negative (433.4 +/- 191.2 mumol/mol creatinine, p = 0.0005) diabetics at onset of disease compared with age-matched control subjects (118.1 +/- 33.2 mumol/mol creatinine). No significant difference in urinary neopterin levels was observed between diabetic groups. After the first stages of disease (greater than 5 months from onset), a significant difference (p = 0.0002) in urinary neopterin excretion was found between longer standing ICA positive patients and controls, but not between ICA negative diabetics and controls. In longer standing diabetics, neopterin levels were significantly higher in ICA positive patients than in ICA negative patients (544.6 +/- 341.3 versus 201.7 +/- 180 mumol/mol creatinine, p = 0.0002). No correlation between newly diagnosed or longer standing patients and HbA1c levels was found. Our results suggest that increased neopterin excretion in type 1 diabetes seems to be a sensitive indicator for the activation of cell-mediated immunity even when ICA are undetectable.
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PMID:Relationship between urinary neopterin excretion and islet cell antibodies in type 1 (insulin-dependent) diabetes. 181 78

Tumour necrosis factors alpha and beta (TNF-alpha and TNF-beta) and gamma interferon (IFN-gamma) were measured by ELISA in the supernatants of phytohaemagglutinin (PHA)-activated peripheral blood mononuclear cells (PBMNC) from 98 individuals (60 controls and 38 patients with insulin-dependent diabetes mellitus [IDDM]). The PBMNC were incubated with varying concentrations of PHA (0, 1, 5, and 10 micrograms/ml) for 72 h. In our population study we observed a correlation between the levels of secretion of TNF-alpha and IFN-gamma but not TNF-beta. The complete data set was analysed by non-parametric tests, and no associations with HLA phenotypes existed. Reduced levels of TNF-beta, but not TNF-alpha or IFN-gamma, secretion were found in IDDM patients stimulated with 1 and 5 micrograms/ml of PHA (P = 0.001 and 0.02 respectively). None of the lymphokine secretion levels at any PHA concentration correlated with particular HLA phenotypes. Analysis of the natural log-transformed data indicated that only for the TNF-beta levels (at 5 micrograms/ml PHA) could subjects be divided into high and low secretors, which also did not correlate with a particular HLA-B or -DR antigen.
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PMID:The effect of HLA and insulin-dependent diabetes mellitus on the secretion levels of tumour necrosis factors alpha and beta and gamma interferon. 212 64

The in vitro production of interferon-alpha was studied in cultures of peripheral blood mononuclear cells from children with insulin-dependent diabetes. Significantly lower levels (p less than 0.01) of interferon (median 64 IU/ml) were found in mumps antigen stimulated cultures of IDDM patients compared to control children (median 256 IU/ml) whereas no differences between groups were found in the amount of interferon induced by Coxsackie B pool antigen or live Sendai virus.
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PMID:Low levels of mumps virus antigen induced interferon-alpha production in insulin-dependent diabetes. 256 52

Eight patients with type I diabetes mellitus (D-I), seven patients with type II diabetes mellitus (D-11) and 8 healthy donors were examined. The disease standing did not exceed 1 year since the moment of the diagnosis establishment. The patients with D-I manifested activation of natural killers (NK) as compared to their activity in the donors and patients with D-II (76.05 +/- 6.5%, 52.33 +/- 9.55% and 55.39 +/- 10.63%, respectively, p less than 0.01) in the presence of the attenuated response of NK to interleukin-2 and alpha-interferon, determined by NK prestimulation. The amount of NK (CD16-positive) in D-I was significantly less than in the donors and patients with D-II. The high activity of NK in D-I correlated with an increase of receptor expression for transferrin on the mononuclear cells of peripheral blood. At the same time 5 out of the 8 patients with D-I and 2 patients with D-II out of the 7 demonstrated the rise of serum alpha-interferon (in the titer 1:40 and over). Activation of NK and the rise of serum interferon may be due to viral etiology of the disease and may play a role in the autoimmune process in patients suffering from D-I.
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PMID:[The functional activity and count of the natural killer cells in patients with recently diagnosed diabetes mellitus types I and II]. 260 54

This study compares the binding of a human recombinant alpha-interferon to peripheral blood mononuclear cells (PBMC) from patients with insulin dependent diabetes (IDDM) mellitus and control subjects. Diurnal and longer term of variation, feeding, fasting and haemoglobin glycosylation were examinated for their influence on interferon binding to PBMC. No gross differences in binding were demonstrated, in particular no effect of glucose levels was seen on the binding of interferon alpha-2 to PBMC.
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PMID:Estimates of normal binding of a human recombinant alpha interferon to peripheral blood mononuclear cells from a study matching healthy subjects to subjects with insulin dependent diabetes. 281 91

Of 37 pancreases removed at necropsy from patients with type 1 diabetes 34 had residual beta cells. In 33 of the 34 the beta cells were positive for immunoreactive alpha-interferon, and this finding in islets was related to hyperexpression of class I major histocompatibility complex (MHC) antigens. Of islets showing class I hyperexpression 93% contained alpha-interferon compared with 0.4% of those showing no hyperexpression. Among 80 control pancreases significant numbers of beta cells containing alpha-interferon were present only in 4 cases of acute infantile viral pancreatitis, known to be caused by Coxsackie-B viral infection in 3 cases. Chronic viral infection of beta cells may underlie the pathogenesis of some cases of type 1 diabetes.
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PMID:Immunoreactive alpha-interferon in insulin-secreting beta cells in type 1 diabetes mellitus. 289 93

Aberrant expression of major histocompatibility (MHC) antigens has been implicated as a factor contributing to organ-specific autoimmunity, such as progressive loss of pancreatic beta cells in type 1 diabetes. We investigated the potential of a rat beta cell tumour, RINM5F, to express enhanced levels of MHC antigens in vitro. To this purpose we treated RINM5F cells in vitro with recombinant rat gamma interferon (rIF gamma). We used monoclonal antibodies to RT1.A (class I) and RT1.B (class II) antigens of the rat MHC in conjunction with flowcytometry and immunoperoxidase techniques to analyse the expression of MHC antigens. Untreated RINM5F cells express low levels of RT1.A, whereas they are negative for RT1.B. Treatment with rIF gamma appeared to increase the expression of RT1.A antigens substantially. Most importantly, RT1.B antigens were newly expressed by rat insulinoma cells in vitro after treatment with rIF gamma. To our knowledge this is the first documentation of the potential of beta cells or their derivatives to express class II MHC antigens following IF gamma-treatment. This mechanism may play an important role in the augmentation and perpetuation of insulitis leading to type 1 diabetes mellitus.
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PMID:Recombinant gamma interferon induces class II major histocompatibility complex antigens on insulinoma cells. 303 89

Autopsy pancreases were studied from 14 patients who had idiopathic Addison's disease. One patient had been diabetic for 12 years and three patients were found to be diabetic during their terminal admission. While there was no evidence of diabetes or destruction of insulin-secreting beta cells in the remaining 10 patients, islets in one pancreas exhibited many of the histological and immunohistochemical features seen in the patients with recent onset diabetes. These included the presence of alpha-interferon in endocrine cells, hyper-expression of class I major histocompatibility complex molecules by endocrine cells in islets where alpha-interferon was also present, aberrant expression of class II major histocompatibility complex molecules by endocrine cells and the presence of insulitis. Since the combination of these changes has only been described in type 1 diabetes it is thought that the appearances seen in this pancreas were those of prediabetes.
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PMID:The pancreas in idiopathic Addison's disease--a search for a prediabetic pancreas. 339 44

Two patients with newly diagnosed insulin dependent diabetes mellitus were treated with human leukocyte interferon based on the hypothesis that the diabetes was induced by an active viral infection in the pancreatic islets and could be arrested. High peak levels of serum interferon were achieved (100-200 U/ml) with minimal systemic side effects. There was no sustained therapeutic benefit as measured by increased production of endogenous insulin, or of C-peptide, or by a lower requirement for exogenous insulin. Further trials with interferon treatment should be undertaken only if evidence of active viral infection (culture, antigen detection) can be associated with insulin dependent diabetes onset and these markers followed during treatment.
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PMID:Human leukocyte interferon treatment of two children with insulin dependent diabetes. 616 82


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