[The 1998 Apollinaire Bouchardat Prize. Autoantigens and type 1 diabetes: from physiopathology to therapeutics].
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Autoantigens↗
Biomedical subjects
C Thivolet
Publications and source records attributed to C Thivolet.
[Evaluation of the hospital management of insulin-dependent diabetics].
OBJECTIVE: There is a known relationship between blood glucose control and development or progression of complications in diabetes mellitus. The aim of our study was to assess the quality of hospital care in patients with insulin-dependent diabetes. PATIENTS AND METHODS: A prospective study was conducted over a 6-month period (April 95-September 95) to perform a clinical audit comparing results obtained with care standards. The study group included 257 consecutive patients (age range 15-39 years) who consulted the hospital outpatient clinic of were hospitalized for insulin-dependent diabetes mellitus RESULTS: Results differed depending on the care standards used for comparison. There were 45 patients (17%) who consulted 4 times or more; 43% of the patients were not hospitalized and 32% did not had a fundus examination during the preceding year. There was a 51% deviation from the standard number of capillary blood glucose measurements and 72% of the patients stated they adapted their insulin dose. Mean glycosylated hemoglobin level (HPLC method) was 9.78 +/- 2.37% (standard = 7%). CONCLUSION: This assessment of hospital care demonstrated a deviation of medical surveillance from standard care. More frequent consultations would help improve patient information. It is important to recall that an annual hospitalization and rigorous application of clinical surveillance with annual fundus examination are essential. Information provided by physicians, nurses and dietitians should be an integral part of hospital care. Likewise, it is undoubtedly useful to provide psychological counselling for diabetic patients. A reassessment should evaluate the impact of such recommendations in order to determine the impact, in terms of reduced mortality, of improved hospital care.
Adolescent↗
A cholera toxoid-insulin conjugate as an oral vaccine against spontaneous autoimmune diabetes.
Mucosally induced immunological tolerance is an attractive strategy for preventing or treating illnesses resulting from untoward inflammatory immune reactions against self- or non-self-antigens. Oral administration of relevant autoantigens and allergens has been reported to delay or suppress onset of clinical disease in a number of experimental autoimmune and allergic disorders. However, the approach often requires repeated feeding of large amounts of tolerogens over long periods and is only partly effective in animals already systemically sensitized to the ingested antigen such as in animals already harboring autoreactive T cells, and thus presumably also in humans with an autoimmune disease. We have recently shown that oral administration of microgram amounts of antigen coupled to cholera toxin B subunit (CTB), can effectively suppress systemic T cell reactivity in naive as well as in immune animals. We now report that feeding small amounts (2-20 microg) of human insulin conjugated to CTB can effectively suppress beta cell destruction and clinical diabetes in adult nonobese diabetic (NOD) mice. The protective effect could be transferred by T cells from CTB-insulin-treated animals and was associated with reduced lesions of insulitis. Furthermore, adoptive co-transfer experiments involving injection of Thy-1,2 recipients with diabetogenic T cells from syngeneic mice and T cells from congenic Thy-1,1 mice fed with CTB-insulin demonstrated a selective recruitment of Thy-1,1 donor cells in the peripancreatic lymph nodes concomitant with reduced islet cell infiltration. These results suggest that protection against autoimmune diabetes can be achieved by feeding minute amounts of a pancreas islet cell autoantigen linked to CTB and appears to involve the selective migration and retention of protective T cells into lymphoid tissues draining the site of organ injury.
Administration, Oral↗
Prevalence and parental origin of de novo RET mutations in multiple endocrine neoplasia type 2A and familial medullary thyroid carcinoma. Le Groupe d'Etude des Tumeurs a Calcitonine.
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Adult↗
[Pre-diabetes type 1. Evaluation of current clinical trials].
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Clinical Trials as Topic↗
Massive weight loss does not restore normal insulin secretory pulses in obese patients with type 2 (non-insulin-dependent) diabetes mellitus.
To study the effects of massive weight loss on insulin secretion, we analysed the oscillations of fasting peripheral insulin levels in obese patients who underwent vertical banded gastroplasty as treatment for morbid obesity. Patients were studied before and 6 months after surgery. Serial measurements of plasma free insulin levels were obtained in duplicates from 0 to 60 min at one-minute intervals. Insulin levels were then analysed by autocorrelation and Fourier transformation. In normal controls and obese patients, the first oscillatory insulin component was detected between 10 and 14 min. Compared to obese controls (n = 4), overt Type 2 diabetic patients (n = 4) had reduced amplitudes of insulin pulses and no oscillatory component. These defects were not as pronounced in patients with impaired glucose tolerance (IGT) after an oral glucose tolerance test (OGTT) (n = 5). When detected, the periodicity of the oscillations occurred at different periods. In 3/5 IGT patients, the first positive peak of correlation was found at 13.3 +/- 2.3 min. Weight loss (mean +/- SD) after 6 months was 24.3 +/- 3.7 for subjects with normal glucose tolerance (NGT), 37.9 +/- 9 for those with IGT and 29.8 +/- 5 kgs for Type 2 diabetic subjects. After weight loss, insulin oscillatory activity was detected in 4/5 IGT patients, with a period of 13 +/- 3 min. Weight loss did not reverse the defects observed in obese diabetic patients despite a significant reduction in peripheral insulin levels from 28.6 +/- 6 to 15.6 +/- 6 mU/l (p < 0.05). Insulin values remained higher than in obese controls (7.82 +/- 2, p < 0.05), and Type 2 patients remained mildly hyperglycaemic. These findings indicate that beta-cell activity is abnormal in Type 2 diabetic patients. The absence of modification after weight loss suggests that inherent beta-cell defects may contribute to hyperglycaemia.
Activity Cycles↗
Four IgG anti-islet human monoclonal antibodies isolated from a type 1 diabetes patient recognize distinct epitopes of glutamic acid decarboxylase 65 and are somatically mutated.
The selective destruction by an autoimmune process of the beta cells in the pancreas is the hallmark of the type 1 insulin-dependent diabetes mellitus. What triggers islet cell-specific autoreactive T and B cells, however, remains unclear. Identification of the targets of the anti-islet cell autoantibodies frequently found in insulin-dependent diabetes mellitus patients and analysis of their sequences should provide some insights into the nature of this disease. We have combined EBV transformation with CD40 activation of peripheral B cells from one patient with insulin-dependent diabetes mellitus to isolate four B cell clones that secrete islet cell-specific autoantibodies, These four human monoclonal autoantibodies are of the IgG1 isotype, and they each recognize a different epitope of the glutamic acid decarboxylase enzyme. Analysis of their variable gene sequences shows that, while clonally unrelated, three of the four human monoclonal autoantibodies use a member of the VH4 family, and two have rearranged the same delta light chain variable gene. The IgG1 isotype of the four autoantibodies as well as the presence of somatic mutations in both heavy and light chain genes provide concrete evidence for their derivation by a T cell-dependent immune response.
Adult↗
[Screening and prediction of diabetes mellitus in children].
It is now possible to identify subjects presenting a high risk to develop type 1 (insulin-dependent) diabetes mellitus using immunogenetic and metabolic markers. These markers indicate an ongoing autoimmune process directed toward beta cells which is responsible for insulin deficiency. Combination of several markers like islet cell (ICA) anti-glutamate decarboxylase (GAD) or anti-insulin (IAA) antibodies increases the specificity up to 100% in first degree relatives of diabetic patients. In the general population where 90% of new cases may occur, it is important to increase the specificity and sensitivity of the current markers. Several preventive therapeutic trials have started in high risk relatives using low doses of subcutaneous insulin with a beta cell rest effect or tolerance protocols using oral administration of insulin.
Animals↗
Active suppression of diabetes after oral administration of insulin is determined by antigen dosage.
We have previously demonstrated that feeding six-week-old female mice with 20 units of human insulin every 2 - 3 days for 15 or 30 days induced an active mechanism of suppression through the generation of regulatory T cells that reduced the number of successful diabetic transfers in irradiated NOD recipients. In the present study, we analyzed the effects of antigen dosage and the critical period of cell injection to obtain protection. The effects of the dose of insulin feeding were therefore compared during cotransfer experiments of 5 x 10(6) T cells from diabetic mice and 5 x 10(6) T cells from the spleen of mice receiving 10 units, 20 units, or 40 units of insulin or saline every 2 - 3 days for 15 days. Only T lymphocytes from mice fed with 20 units conferred active cellular protection during adoptive transfer with a significant delay in diabetes onset (p = 0.002). No significant difference was noticed during histological analysis of pancreatic glands, indicating tha insulitis was not prevented. However, mice receiving T lymphocytes from the 20 units of insulin-fed animals had a milder form of inflammation, with a significantly lower percentage of severely infiltrated islets. Injecting regulatory T cells 7 days and 14 days after iv injection of diabetogenic T cells did not modify the incidence curves of diabetes in the recipients, suggesting that cellular interactions and delay in cell trafficking were determinants. These results may have important clinical implications in humans. In conclusion, this study indicates the importance but also the limits of antigen therapy in type I diabetes. Antigen dosage is a critical element for active suppression. Such analysis is important to perform in humans before the initiation of a large-scale prevention trial in prediabetic individuals.
Administration, Oral↗
Lymphocyte function associated antigen-1, integrin alpha 4, and L-selectin mediate T-cell homing to the pancreas in the model of adoptive transfer of diabetes in NOD mice.
The involvement of adhesion molecule in the process of T-cell homing to the pancreas was investigated in the model of the T-cell transfer of type I diabetes in NOD mice. Treatment of mice using monoclonal anti-lymphocyte function associated antigen (LFA)-1, anti-integrin alpha 4, anti-intercellular adhesion molecule (ICAM)-1, and anti-L-selectin antibodies (monoclonal antibodies [mAbs]) gave rise to a partial or complete prevention of diabetes via different mechanisms of protection. On day 20 posttransfer, diabetes was only observed in control mice (26 of 32) and in few mice treated with the anti-L-selectin mAbs (3 of 24). On day 60, the best protection was observed using the anti-LFA-1 or the anti-integrin alpha 4 mAbs with 3 of 11 and 2 of 5 diabetic mice, respectively. On day 20, no insulitis was observed in the pancreases of mice treated with these mAbs compared with the pancreases of controls, suggesting that such treatment blocked the penetration of T-cells into the islets. In vitro adhesion assays confirmed that adhesion of T-cells to the pancreatic endothelium was blocked, except when using the anti-L-selectin mAb, which induced a modification of the traffic of the transferred T-cells; the ability of T-cells to migrate into the pancreatic lymph nodes was significantly reduced (10.4 vs. 22%). Anti-LFA-1 mAbs did not modify such T-cell trafficking. The present study, therefore, elucidates the role of LFA-1, integrin alpha 4, and L-selectin in T-cell homing to the pancreas, first step of the cascade of events leading to type I diabetes.
Animals↗
Effects of insulin like growth factor-1 and insulin on effector T cells generating autoimmune diabetes.
To compare the protective effects of IGF-1 and insulin on the autoimmune process of beta-cell destruction, permissive NOD recipients were adoptively transferred with 7 x 10(6) autoreactive T cells from diabetic NOD mice and then administered either 10 micrograms of rhIGF-1 or 0.5 unit of regular insulin subcutaneously twice daily for three weeks. The final incidence of successful transfers of diabetes observed at day 22 was significantly reduced in 1/12 mice (8.3%) treated with IGF-1, while diabetes was observed in 4/10 (40%) receiving insulin and 7/11 (63.4%) controls. A marked reduction of insulitis during histological analysis of the pancreatic glands of IGF-1 or insulin-treated mice was also observed. Non-diabetic mice treated with rhIGF-1 had a higher mean +/- SD percentage of intact islets (68.9 +/- 36% vs 10.7 +/- 13%, p < 0.01) and a lower percentage of severely infiltrated islets (5.7 +/- 9.8% vs 30.3 +/- 21%) than non-diabetic control mice. Insulin reduced islet-cell infiltration, though to a lesser extent, with a high percentage of normal islets (55.2 +/- 31%, p < 0.02). Some mice developed diabetes and severe islet-cell infiltration despite rhIGF-1 or insulin, thus indicating that some committed T cells were still able to invade islets and cause beta-cell destruction. To evaluate the effects of rhIGF-1 and insulin on cell trafficking in recipient mice, T cells from diabetic NOD Thy-1, 2 mice injected into congenic NOD-N Thy-1, 1 mice were monitored three weeks after adoptive cell transfer. The percentage of Thyq-1.2+ T cells was significantly reduced in the spleen (10.8 +/- 1.3% vs 17.2 +/- 3.9%, p = 0.004) of rhIGF-1 treated mice as compared to the thymus (68.4 +/- 7.9% vs 72.87 +/0 6.2, p = 0.306). Similar experiments performed in mice treated with insulin revealed no significant differences in the percentages of Thy-1,2+ T cells compared to controls in the spleen (l4.3 +/- 1.4%), thymus (84 +/- 2.5%) or pancreatic lymph nodes (21.5 +/- 1.6% vs 23.4 +/- 1.5%) of treated animals. These results suggest that rhIGF-1, as compared to insulin, could influence T-cell trafficking to the lymphoid organs in addition to affecting beta cells. These findings may have important implications for new preventive strategies in human Type 1 diabetes mellitus.
Animals↗
[Pituitary enlargement in congenital adrenal hyperplasia].
The aim of the suppression of pituitary adrenal axis in the management of patients with congenital adrenal hyperplasia is to reduce the hypersecretion of adrenal androgens. However, the local consequences of the hyperreactivity of corticotropin cells during inadequate therapy is not well defined. In this case report, we present the observation of a 28-year-old patient with congenital adrenal hyperplasia with inadequate treatment in whom a pituitary enlargement was detected after MR imaging for headaches. This observation underlines the need for a pituitary follow-up in these specific patients.
Adrenal Hyperplasia, Congenital↗
[Treatment of severe obesity by calibrated vertical gastroplasty. 55 cases].
OBJECTIVES: Evaluate short-term outcome of calibrated vertical gastroplasty in obese subjects. METHODS: Calibrated vertical gastroplasty was performed in 55 obese subjects (BMI 43 +/- 1; age range 20-59 year). There were no post-operative complications. All the subjects were followed for 6 months and thirty one for a year. RESULTS: Weight loss reached 28 kg at 6 months and 36 kg at 1 year with an improvement in functional manifestations, especially for dyspnoea and, in half of the subjects, for signs of depression. New or worsened psychiatric problems were observed in 4 subjects. Post-prandial vomiting persisted for 1 year in 28 patients. Dietary intake was lowered (946 +/- 61 kcal/day) as was protein intake (43 +/- 3 g/24 hr). Impaired glucose tolerance, raised serum insulin, triglyceride and androgen levels were corrected in patients with abnormal levels before surgery. Serum vitamin B1 declined. CONCLUSION: These favourable results in the weight curve, functional problems and metabolic data should not mask the disadvantages and potential risks involved. Long-term prospective studies are required to determine the precise indications for this technique.
Adult↗
Autoantibodies to glutamate decarboxylase in a patient with cerebellar cortical atrophy, peripheral neuropathy, and slow eye movements.
OBJECTIVE: To study the existence of autoimmunity against the cerebellum in patients with sporadic cortical cerebellar atrophy. DESIGN: The presence of autoantibodies against the cerebellum in the serum and cerebrospinal fluid samples that were obtained from patients with sporadic cortical cerebellar atrophy and control patients was investigated by using immunohistochemical techniques. SETTING: University hospital and research laboratory in Lyons, France. PATIENTS: Eight patients with cortical cerebellar atrophy that was associated with or without other neurological symptoms; 350 patients with various neurological diseases; and 33 normal, healthy subjects. OUTCOME MEASURES: Serum and cerebrospinal fluid anti-cerebellar autoantibodies were investigated by using indirect immunofluorescence techniques in rat cerebellum. To characterize antigen labeled by patient's serum, we used an immunotrapping enzyme activity assay of glutamate decarboxylase. RESULTS: Serum and cerebrospinal fluid samples that were taken from one patient with sporadic cortical cerebellar atrophy associated with peripheral neuropathy and slow eye movements contained anti-glutamate decarboxylase autoantibodies. CONCLUSIONS: These results suggest a participation of autoimmunity in the pathogenesis of some cases of sporadic cerebellar cortical atrophy and the involvement of the cerebellar gamma-aminobutyric acid-ergic system in the pathogenesis of this disease.
Adult↗
Pancreatic lymph nodes are early targets of T cells during adoptive transfer of diabetes in NOD mice.
The circulation pathway of diabetogenic T lymphocytes prior to insulitis was investigated using adoptive transfer of diabetes in the non-obese diabetic (NOD) mouse model. Transferred T cells were distinguished from recipient T cells using two strains of mice congenic at the Thy1 locus. They were monitored in the pancreas and in several lymphoid organs including thymus, spleen, and lymph nodes from pancreatic, mesenteric, axillary, inguinal and lomboaortic areas, from Day 0 to Day 15 after the adoptive lymphocytic transfer. Immunohistochemical studies showed that at Day 2 post-transfer the pancreatic lymph nodes (PLN) and to a lesser extent the spleen, are the first two organs to be infiltrated. The amount of T cells of donor origin using quantitative flow cytometric analysis was 4% and 2.6% respectively. This percentage increased to 19% in the PLN at Day 15 and did not exceed 7% in the spleen. Analysis of the expression of IL-2 receptor present at the surface of activated T lymphocytes showed that 73% of donor T cells were activated in the PLN within 3 days post-transfer in contrast to 0% in the spleen. The accumulation and activation of T cells in the PLN may imply a role of these lymphoid organs in harbouring the diabetogenic T cells during the early steps of the disease.
Animals↗
Reactivity of islet cell antibodies (ICA) to recombinant glutamic acid decarboxylase (GAD).
To study the heterogeneity of islet cell antibodies (ICA), recombinant rat and human GAD65 expressed as bacterial fusion proteins were used to inhibit ICA reactivity in sera from recent onset type 1 diabetic children and ICA-positive first degree relatives of diabetic patients. Rat GAD65 was expressed as a fusion protein in the expression vector RSET and inhibited ICA (GAD+ICA) in 26% of 23 recent onset patients, 29% of 14 ICA positive first degree relatives (FDR) who progressed to diabetes (prediabetics) and 50% of 20 FDR who did not progress to diabetes 18 months to 5 years (31 +/- 14 months) after collection of the sample. GAD+ICA were inversely associated with the presence of insulin autoantibodies (IAA) (P = 0.006). GAD antibodies (GAD-Ab) were also detected by immunoprecipitation of in vitro transcribed and translated [35S] methionine-labelled human GAD65. GAD-Ab were present in 83% of recent onset patients, 86% of prediabetics and 95% of the relatives who did not progress to diabetes. The level of GAD-Ab was higher in the presence of GAD+ICA (1.39 +/- 0.57 vs 0.79 +/- 0.6 index units; P = 0.001). ICA levels were higher in GAD-Ab negative than in GAD-Ab positive sera (377 +/- 256 vs 195 +/- 231 JDFU; P = 0.03). Our results confirm that a recombinant GAD65 fusion protein can be used to detect ICA heterogeneity. However, neither inhibition of ICA with recombinant GAD, nor direct detection of GAD-Ab improved the prediction of progression to clinical diabetes in ICA positive FDR.
Adolescent↗
Insulin-like growth factor-1 (IGF-1) protects NOD mice from insulitis and diabetes.
To evaluate the effect of IGF-1 on the autoimmune process of beta cell destruction, permissive non-obese diabetic (NOD) recipients were adoptively transferred with 7 x 10(6) autoreactive T cells from diabetic NOD mice and were administered subcutaneously 10 micrograms rhIGF-1, twice daily for 3 weeks. Administration of rhIGF-1 reduced the final incidence of successful transfers of diabetes observed in only 6/24 mice (25%) versus 12/21 (57%) in control mice. A marked reduction of insulitis during histological analysis of pancreatic glands was also observed. Mice treated with rhIGF-1 had a higher percentage of intact islets (48.6 +/- 12% versus 1.6 +/- 1.1%, P = 0.001) and a lower percentage of infiltrated islets. Islets from rhIGF-1-treated mice had a more intense insulin staining reflecting a higher beta cell mass, but no difference was observed in the amount of insulin content of pancreatic extracts and in the amounts of mRNA transcripts for proinsulin. No difference was also observed in the titres of three islet cell antibody (ICA)-positive sera and in the pattern of A2B5 staining. Some mice developed diabetes and severe islet cell infiltration despite rhIGF-1, thus indicating that some committed T cells were still able to invade the islets and cause beta cell destruction. The percentages of CD4+ and CD8+ T cells in the spleen of experimental mice were similar. To evaluate the effects of rhIGF-1 on cell trafficking in recipient mice, T cells from diabetic NOD Thy-1,2 mice injected into congenic NOD-N Thy-1,1 mice were monitored 3 weeks after adoptive cell transfer. The percentage of Thy-1,2+ T cells was significantly reduced in the spleen (10.8 +/- 1.3% versus 17.2 +/- 3.9%, P = 0.004) of rhIGF-1 treated mice in contrast to the thymus (68.4 +/- 7.9% versus 72.87 +/- 6.2%, P = 0.306), suggesting that rhIGF-1 could influence T cell trafficking to the lymphoid organs. The findings that rhIGF-1 has protective effects in autoimmune diabetes opens new perspectives for future experiments as well as for preventive strategies in human type I diabetes.
Animals↗
[Latero-cervical thyroid tissue and congenital hypothyroidism revealed in adult age].
It is generally admitted that in front of tissues of thyroid origin found in latero-cervical position, the clinician should look for the presence of an occult thyroid carcinoma. This position is therefore against the diagnosis of lateral aberrant thyroids or benign metastatic thyroidosis that have been evocated in the past. We present the case of a 59 yr old woman in whom the diagnosis of benign latero-cervical mass of thyroid origin was made in association of an undiagnosed congenital hypothyroidism due to an ectopic thyroid gland in a sub-lingual position. This observation as well as recent published observations are in contrast with the current medical practices which should be discussed according to the location of the cervical mass and to precise histopathological features.
Age Factors↗