Lucy Chaillous

Oral insulin administration and residual (β-cell function in recent-onset type 1 diabetes: a multicentre randomised controlled trial

Summary Background Oral administration of autoantigens can slow the progression of β-cell destruction in non-obese diabetic mice. We investigated whether oral administration of recombinant human insulin could protect residual β-cell function in recent-onset type 1 diabetes. Methods We enrolled 131 autoantibody-positive diabetic patients aged 7–40 years within 2 weeks of diagnosis (no ketoacidosis at diagnosis, weight loss Findings Baseline C-peptide and haemoglobin A lc concentrations were similar in the three groups. During follow-up, there were no differences between the groups assigned 2·5 mg or 7·5 mg oral insulin or placebo in subcutaneous insulin requirements, haemoglobin A lc concentrations, or measurements of fasting (mean at 12 months 0·18 [SD 0·17], 0·17 [0·17], and 0·17 [0·12] nmol/L) or stimulated C-peptide concentrations (glucagon-stimulated 0·39 [0·38], 0·37 [0·39], and 0·33 [0·24] nmol/L; meal-stimulated 0·72 [0·60], 0·49 [0·49], and 0·57 [0·51 nmol/L]. Neither age nor C-peptide concentration at entry influenced treatment effects. No differences were seen in the time-course or titres of antibodies to insulin, glutamic acid decarboxylase, or islet antigen 2. Interpretation At the doses used in this trial, oral administration of insulin initiated at clinical onset of type 1 diabetes did not prevent the deterioration of β-cell function.

CD8+ T-Cell Responses Identify β-Cell Autoimmunity in Human Type 1 Diabetes

Despite the understanding that type 1 diabetes pathogenesis is mediated by T-cells, detection of these rare lymphocytes remains largely elusive. Suitable T-cell assays are highly needed, since they could offer preclinical diagnoses and immune surrogate end points for clinical trials. Although CD4+ T-cell assays have met with limited success, CD8+ T-cells are increasingly recognized as key actors in the diabetes of the NOD mouse. CD8+ T-cells are likely to play a role also in humans and may provide new markers of β-cell autoimmunity. Taking advantage of a panel of HLA-A2–restricted β-cell epitopes derived from preproinsulin, GAD, and islet glucose-6-phosphatase catalytic subunit-related protein (IGRP), we have implemented an islet-specific CD8+ T-cell interferon-γ enzyme-linked immunospot (ISL8Spot) assay. The ISL8Spot assay is capable of detecting and quantifying β-cell–reactive CD8+ T-cells directly ex vivo, without any preliminary expansion, using either fresh or frozen samples. Positive ISL8Spot responses separate new-onset diabetic and healthy samples with high accuracy (86% sensitivity, 91% specificity), using as few as five immunodominant epitopes. Moreover, sensitivity reaches 100% when the ISL8Spot assay is complemented by antibody determinations. Combination of CD8+ T-cell measurements with immune intervention strategies may open new avenues toward type 1 diabetes prediction and prevention.

The Type and the Position of HNF1A Mutation Modulate Age at Diagnosis of Diabetes in Patients with Maturity-Onset Diabetes of the Young (MODY)-3

OBJECTIVE—The clinical expression of maturity-onset diabetes of the young (MODY)-3 is highly variable. This may be due to environmental and/or genetic factors, including molecular characteristics of the hepatocyte nuclear factor 1-α (HNF1A) gene mutation. RESEARCH DESIGN AND METHODS—We analyzed the mutations identified in 356 unrelated MODY3 patients, including 118 novel mutations, and searched for correlations between the genotype and age at diagnosis of diabetes. RESULTS—Missense mutations prevailed in the dimerization and DNA-binding domains (74%), while truncating mutations were predominant in the transactivation domain (62%). The majority (83%) of the mutations were located in exons 1- 6, thus affecting the three HNF1A isoforms. Age at diagnosis of diabetes was lower in patients with truncating mutations than in those with missense mutations (18 vs. 22 years, P = 0.005). Missense mutations affecting the dimerization/DNA-binding domains were associated with a lower age at diagnosis than those affecting the transactivation domain (20 vs. 30 years, P = 10−4). Patients with missense mutations affecting the three isoforms were younger at diagnosis than those with missense mutations involving one or two isoforms (P = 0.03). CONCLUSIONS—These data show that part of the variability of the clinical expression in MODY3 patients may be explained by the type and the location of HNF1A mutations. These findings should be considered in studies for the search of additional modifier genetic factors.

The Frequency and Immunodominance of Islet-specific CD8+ T-cell Responses Change after Type 1 Diabetes Diagnosis and Treatment

OBJECTIVE—Islet-reactive CD8+ T-cells play a key role in the pathogenesis of type 1 diabetes in the NOD mouse. The predominant T-cell specificities change over time, but whether similar shifts also occur after clinical diagnosis and insulin treatment in type 1 diabetic patients is unknown. RESEARCH DESIGN AND METHODS—We took advantage of a recently validated islet-specific CD8+ T-cell γ-interferon enzyme-linked immunospot (ISL8Spot) assay to follow responses against preproinsulin (PPI), GAD, insulinoma-associated protein 2 (IA-2), and islet-specific glucose-6-phosphatase catalytic subunit-related protein (IGRP) epitopes in 15 HLA-A2+ adult type 1 diabetic patients close to diagnosis and at a second time point 7–16 months later. RESULTS—CD8+ T-cell reactivities were less frequent at follow-up, as 28.6% of responses tested positive at type 1 diabetes diagnosis vs. 13.2% after a median of 11 months (P = 0.003). While GAD and IA-2 autoantibody (aAb) titers were unchanged in 75% of cases, the fraction of patients responding to PPI and/or GAD epitopes by ISL8Spot decreased from 60–67 to 20% (P < 0.02). The previously subdominant IA-2206–214 and IGRP265–273 peptides were newly targeted, thus becoming the immunodominant epitopes. CONCLUSIONS—Shifts both in frequency and in immunodominance of CD8+ T-cell responses occur more rapidly than do changes in aAb titers. These different kinetics may suggest complementary clinical applications for T-cell and aAb measurements.

Assessment of Patient-Led or Physician-Driven Continuous Glucose Monitoring in Patients With Poorly Controlled Type 1 Diabetes Using Basal-Bolus Insulin Regimens A 1-year multicenter study

OBJECTIVE The benefits of real-time continuous glucose monitoring (CGM) have been demonstrated in patients with type 1 diabetes. Our aim was to compare the effect of two modes of use of CGM, patient led or physician driven, for 1 year in subjects with poorly controlled type 1 diabetes. RESEARCH DESIGN AND METHODS Patients with type 1 diabetes aged 8–60 years with HbA1c ≥8% were randomly assigned to three groups (1:1:1). Outcomes for glucose control were assessed at 1 year for two modes of CGM (group 1: patient led; group 2: physician driven) versus conventional self-monitoring of blood glucose (group 3: control). RESULTS A total of 257 subjects with type 1 diabetes underwent screening. Of these, 197 were randomized, with 178 patients completing the study (age: 36 ± 14 years; HbA1c: 8.9 ± 0.9%). HbA1c improved similarly in both CGM groups and was reduced compared with the control group (group 1 vs. group 3: −0.52%, P = 0.0006; group 2 vs. group 3: −0.47%, P = 0.0008; groups 1 + 2 vs. group 3: −0.50%, P < 0.0001). The incidence of hypoglycemia was similar in the three groups. Patient SF-36 questionnaire physical health score improved in both experimental CGM groups (P = 0.004). Sensor consumption was 34% lower in group 2 than in group 1 (median [Q1–Q3] consumption: group 1: 3.42/month [2.20–3.91] vs. group 2: 2.25/month [1.27–2.99], P = 0.001). CONCLUSIONS Both patient-led and physician-driven CGM provide similar long-term improvement in glucose control in patients with poorly controlled type 1 diabetes, but the physician-driven CGM mode used fewer sensors.

Clinical characteristics and diagnostic criteria of maturity-onset diabetes of the young (MODY) due to molecular anomalies of the HNF1A gene.

CONTEXT The diagnosis of maturity-onset diabetes of the young type 3 (MODY3), associated with HNF1A molecular abnormalities, is often missed. OBJECTIVE The objective of the study was to describe the phenotypes of a large series of MODY3 patients and to reassess parameters that may improve its diagnosis. DESIGN, SETTING, AND PATIENTS This retrospective multicenter study included 487 unrelated patients referred because of suspicion of MODY3. Genetic analysis identified 196 MODY3 and 283 non-MODY3 cases. Criteria associated with MODY3 were assessed by multivariate analysis. The capacity of the model to predict MODY3 diagnosis was assessed by the area under the receiver-operating characteristic curve and was further validated in an independent sample of 851 patients (165 MODY3 and 686 non-MODY3). RESULTS In the MODY3 patients, diabetes was revealed by clinical symptoms in 25% of the cases and was diagnosed by screening in the others. Age at diagnosis of diabetes was more than 25 yr in 40% of the MODY3 patients. There was considerable variability and overlap of all assessed parameters in MODY3 and non-MODY3 patients. The best predictive model was based on criteria available at diagnosis of diabetes, including age, body mass index, number of affected generations, presence of diabetes symptoms, and geographical origin. The area under the curve of the receiver-operating characteristic analysis was 0.81. When sensitivity was set to 90%, specificity was 49%. CONCLUSIONS Differential diagnosis between MODY3 and early-onset type 2 diabetes remains difficult. Whether the proposed model will improve the pick-up rate of MODY3 diagnosis needs to be confirmed in independent populations.

Immunization of HLA Class I Transgenic Mice Identifies Autoantigenic Epitopes Eliciting Dominant Responses in Type 1 Diabetes Patients

Type 1 diabetes (T1D) results from the autoimmune destruction of pancreatic β cells. CD8+ T cells have recently been assigned a major role in β cell injury. Consequently, the identification of autoreactive CD8+ T cells in humans remains essential for development of therapeutic strategies and of assays to identify aggressive cells. However, this identification is laborious and limited by quantities of human blood samples available. We propose a rapid and reliable method to identify autoantigen-derived epitopes recognized by human CD8+ T lymphocytes in T1D patients. Human histocompatibility leukocyte Ags-A*0201 (HLA-A*0201) transgenic mice were immunized with plasmids encoding the T1D-associated autoantigens: 65 kDa glutamic acid decarboxylase (GAD) or insulinoma-associated protein 2 (IA-2). Candidate epitopes for T1D were selected from peptide libraries by testing the CD8+ reactivity of vaccinated mice. All of the nine-candidate epitopes (five for GAD and four for IA-2) identified by our experimental approach were specifically recognized by CD8+ T cells from newly diagnosed T1D patients (n = 19) but not from CD8+ T cells of healthy controls (n = 20). Among these, GAD114–123, GAD536–545 and IA-2805–813 were recognized by 53%, 25%, and 42% of T1D patients, respectively.

Fulminant type 1 diabetes in Caucasians : A report of three cases

CONTEXT Fulminant type 1 diabetes is a new clinical entity in which the process of beta-cell destruction, and the subsequent progression of hyperglycaemia and ketoacidosis, are extremely rapid. Until now, this subtype of type 1 diabetes has only been reported in the Asian population, especially Japanese and Koreans. CASES We report here on three cases of fulminant type 1 diabetes in Caucasian French women. Both the clinical and biological characteristics of these patients are similar to those reported in Japanese studies. Notably, all patients experienced severe ketoacidosis (pH<7.1) that occurred abruptly after the onset of hyperglycaemic symptoms (<6 days), with near-normal HbA(1c) values at diagnosis (5.6, 6.4 and 6.8%). Patients were treated in the intensive care unit with basal-bolus insulin therapy with no remission of their diabetes; pancreatic islet-related autoantibodies were all negative. Fasting C-peptide levels were undetectable, suggesting complete destruction of pancreatic beta-cells. HLA phenotyping of these Caucasian patients did not find the specific HLA haplotype (DRB1*0405-DQB1*0401) previously found to be linked to fulminant type 1 diabetes in Japanese patients. CONCLUSION These are the first cases of fulminant type 1 diabetes reported in Caucasians. These cases reveal new perspectives as regards the worldwide distribution of this intriguing clinical entity.

Intensity and mechanisms of in vitro xenorecognition of adult pig pancreatic islet cells by CD4+ and CD8+ lymphocytes from Type I diabetic or healthy subjects

Summary The intensity and mechanisms of cell-mediated rejection of pig islet cells were studied in 49 Type I diabetic and 34 healthy subjects. Human peripheral mononuclear cells proliferated strongly in response to pig islet cells (p < 0.001), though with notable interindividual variations (stimulation index 2 to 215). The variance of stimulation index was higher in diabetic than healthy subjects (p < 0.0001). The response to islet cells was stronger (p < 0.01) than that to pig splenocytes. Proliferation in response to islet cells was strongly decreased (p < 0.01) when CD4+ T cells were blocked with monoclonal antibodies, whereas the blocking of CD8+ cells or NK cells gave less pronounced effects. The response to islet cells was decreased (p < 0.01), but not abolished, after antigen-presenting cells were removed. Purified CD4+ cells alone did not proliferate in response to islet cells but recovered their proliferative ability when mixed with antigen-presenting cells, whereas CD8+ cells alone proliferated in the presence of interleukin-2 in response to islet cells. Proliferation was blocked (p < 0.01) by anti-DR monoclonal antibodies. During proliferation in response to islet cells, interleukin-10 increased 43-fold (p < 0.01) but interferon-γ increased only slightly. No statistical differences were detected between diabetic and control subjects with respect to lymphocyte subsets and the recognition mechanisms or to interferon-γ / interleukin-10 production in response to islet cells. These results provide the first detailed information on human cell-mediated xenoreaction to pig islet cells. This situation involves a dominant CD4 class II-restricted Th2 response, with an indirect recognition pathway, as well as a CD8 T-cell response resulting from direct recognition. This strong reaction constitutes a serious obstacle which may vary in degree among subjects. [Diabetologia (1999) 42: 330–335]

Differential β-cell response to glucose, glucagon, and arginine during progression to type I (insulin-dependent) diabetes mellitus

Acute insulin responses to glucose (AIRG), glucagon (AIRGln), and arginine (AIRArg) were evaluated prospectively in nine subjects positive for islet-cell antibodies (ICAs) who later progressed to type I diabetes or impaired glucose tolerance (IGT) (progressors), 64 ICA-positive subjects at risk who did not develop type I diabetes, 365 ICA-negative relatives of diabetic patients who also remained free of the disease, and 89 control subjects. Seven progressors already had a low AIRG at entry into the study, and the other two became low responders 3 to 9 months before diabetes or IGT, with a progressive decline of AIRG over serial intravenous (IV) glucose tolerance tests. At entry into the study, the group of progressors displayed lower AIRG, AIRGln, and AIRArg than the other three groups (P < .001). However, AIRArg was less altered than AIRG. During the course of the prediabetic phase, there was a progressive decline in AIRG and AIRGln analyzed as a function either of time (P < .006) or of basal glycemia (P < .05), ie, two different ways of estimating worsening of the disease process. Conversely, there was no significant decrease in AIRArg with time or with increasing basal glycemia, so that AIRArg was not totally blunted in these prediabetic subjects even a few months before the onset of diabetes. The persistence of a substantial response to arginine, ie, higher than the fifth control percentile, even at a late stage, was confirmed in five of nine diabetic patients tested either at onset of the disease or during non-insulin-receiving remission. Whereas AIRG deteriorates during prediabetes, AIRArg appears to be less altered with time and increased basal glycemia, remaining substantial even at the onset of the disease. This reinforces the supposition that the prediabetic state may be associated with a glucose-specific β-cell functional abnormality in addition to a decreasing β-cell mass.