Publications by authors named "Jean-Jacques Robert"

46 Publications

Targets and teamwork: Understanding differences in pediatric diabetes centers treatment outcomes.

Pediatr Diabetes 2018 05 20;19(3):559-565. Epub 2017 Nov 20.

Clinique Pediatrique/CHL, Diabetes & Endocrine Care CP, Luxembourg, Luxembourg.

Objective: The reason for center differences in metabolic control of childhood diabetes is still unknown. We sought to determine to what extent the targets, expectations, and goals that diabetes care professionals have for their patients is a determinant of center differences in metabolic outcomes.

Research Design And Methods: Children, under the age of 11 with type 1 diabetes and their parents treated at the study centers participated. Clinical, medical, and demographic data were obtained, along with blood sample for centralized assay. Parents and all members of the diabetes care team completed questionnaires on treatment targets for hemoglobin A1c (HbA1c) and recommended frequency of blood glucose monitoring.

Results: Totally 1113 (53% male) children (mean age 8.0 ± 2.1 years) from 18 centers in 17 countries, along with parents and 113 health-care professionals, participated. There were substantial differences in mean HbA1c between centers ranging from 7.3 ± 0.8% (53 mmol/mol ± 8.7) to 8.9 ± 1.1% (74 mmol/mol ± 12.0). Centers with lower mean HbA1c had (1) parents who reported lower targets for their children, (2) health-care professionals that reported lower targets and more frequent testing, and (3) teams with less disagreement about recommended targets. Multiple regression analysis indicated that teams reporting higher HbA1c targets and more target disagreement had parents reporting higher treatment targets. This seemed to partially account for center differences in Hb1Ac.

Conclusions: The diabetes care teams' cohesiveness and perspectives on treatment targets, expectations, and recommendations have an influence on parental targets, contributing to the differences in pediatric diabetes center outcomes.
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http://dx.doi.org/10.1111/pedi.12606DOI Listing
May 2018

A novel NEUROG3 mutation in neonatal diabetes associated with a neuro-intestinal syndrome.

Pediatr Diabetes 2018 05 22;19(3):381-387. Epub 2017 Sep 22.

University of Lille, UMR 8199 - EGID, Lille, France.

Neonatal diabetes mellitus (NDM) is a rare form of non-autoimmune diabetes usually diagnosed in the first 6 months of life. Various genetic defects have been shown to cause NDM with diverse clinical presentations and variable severity. Among transcriptional factor genes associated with isolated or syndromic NDM, a few cases of homozygous mutations in the NEUROG3 gene have been reported, all mutated patients presenting with congenital malabsorptive diarrhea with or without diabetes at a variable age of onset from early life to childhood. Through a targeted next-generation sequencing assay for monogenic diabetes genes, we aimed to search for pathogenic deleterious mutation in a Turkish patient with NDM, severe malabsorptive diarrhea, neurointestinal dysplasia and other atypical features. In this patient, we identified a novel homozygous nonsense mutation (p.Q4*) in NEUROG3. The same biallelic mutation was found in another affected family member. Of note, the study proband presents with abnormalities of the intrahepatic biliary tract, thyroid gland and central nervous system, which has never been reported before in NEUROG3 mutation carriers. Our findings extend the usually described clinical features associated with NEUROG3 deficiency in humans, and question the extent to which a complete lack of NEUROG3 expression may affect pancreas endocrine function in humans.
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http://dx.doi.org/10.1111/pedi.12576DOI Listing
May 2018

High Prevalence of Polycystic Ovary Syndrome in Type 1 Diabetes Mellitus Adolescents: Is There a Difference Depending on the NIH and Rotterdam Criteria?

Horm Res Paediatr 2017 24;87(5):333-341. Epub 2017 Apr 24.

Department of Paediatric Endocrinology, Gynaecology, and Diabetology, Necker - Enfants Malades Teaching Hospital, Assistance Publique - Hôpitaux de Paris, IMAGINE Affiliate, Paris, France.

Background: Polycystic ovary syndrome (PCOS) is more frequently observed in type 1 diabetes mellitus (T1DM) adult women than in nondiabetic women. No such prevalence has yet been studied in adolescent girls with T1DM.

Aim: The aim of this study was to evaluate the prevalence of PCOS in adolescent girls with T1DM and to determine the clinical and hormonal features associated with the disorder.

Methods: A cross-sectional study of 53 adolescent girls (gynecological age >2 years) referred for routine evaluation for T1DM was conducted. We diagnosed PCOS using the National Institutes of Health (NIH) and Rotterdam criteria.

Results: 26.4 and 47.9% of adolescents had PCOS according to NIH (NIH-PCOS) and Rotterdam (Rotterdam-PCOS) criteria. 66.7% of NIH-PCOS adolescents had a complete phenotype associated with hyperandrogenism, oligomenorrhea, and polycystic ovarian morphology, unlike only 33.3% of the Rotterdam-PCOS adolescents. A family history of type 2 diabetes mellitus (T2DM) was more frequent in PCOS than in non-PCOS girls, whichever criteria were used. Late pubertal development and a T1DM diagnosis close to puberty were factors associated with NIH-PCOS.

Conclusion: Adolescents with T1DM had a high prevalence of PCOS. More differences between PCOS and non-PCOS patients were found using the NIH criteria, suggesting that clinical characteristics might be more accurate for diagnosing PCOS in girls with T1DM. A family history of T2DM is associated with a high risk of PCOS.
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http://dx.doi.org/10.1159/000471805DOI Listing
March 2018

Revisiting autoimmune gastritis in children and adolescents with type 1 diabetes.

Pediatr Diabetes 2017 Dec 22;18(8):772-776. Epub 2016 Dec 22.

Université Paris Descartes, Sorbonne Paris Cité, Paris, France.

Objective: Assess the frequency of anti-H /K adenosine triphosphatase (ATPase) autoantibodies (AAB) and symptoms of autoimmune gastritis in children and adolescents with type 1 diabetes (T1D).

Research Design And Methods: Anti-H /K ATPase AAB were measured in 402 children and adolescents (210 boys and 192 girls, 11.1 ± 4.5 years) treated for T1D (screened positive for β-cell AAB), along with search of symptoms of anemia (hemoglobin, serum iron, and ferritin levels) and gastric pain. The AAB specific for thyroperoxydase, thyroglobulin, and transglutaminase were also measured.

Results: Anti-H /K ATPase AAB were present in 6.5% of children. Their frequency increased with age: 4% at 10 years, 10% at 15 years, and 20% at 20 years. Iron deficiency (45% vs 3.8%), iron deficiency anemia (36% vs 3.8%), antithyroid AAB (24% vs 9.7%), and family history of Graves' disease (25% vs 5.6%) were more frequent in patients with anti-H /K ATPase AAB. Two patients, a 13-year-old girl and a 11-year-old boy, experienced symptoms (iron deficiency anemia and epigastric pain) which led to diagnosis of autoimmune gastritis confirmed upon fibroscopy. Both showed high levels of anti-H /K ATPase AAB and atrophic gastritis.

Conclusions: Autoimmune gastritis presents an age-dependent frequency in children and adolescents with T1D but is rarely symptomatic. Screening for anti-H /K ATPase AAB should thus target patients with iron deficiency, anemia, epigastralgia, autoimmune thyroiditis, or age over 15 years.
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http://dx.doi.org/10.1111/pedi.12482DOI Listing
December 2017

Diabetes knowledge in adolescents with type 1 diabetes and their parents and glycemic control.

Pediatr Diabetes 2017 Nov 11;18(7):559-565. Epub 2016 Oct 11.

Endocrinologie, Gynécologie et Diabétologie Pédiatrique, Hôpital Necker-Enfants malades, Paris, France.

Objective: To evaluate diabetes knowledge and skills (DKS) in adolescents (>10 year) with type 1 diabetes (T1D) and their parents, and its effect on glycemic control.

Methods: A ready-to-use program and a standardized questionnaire comprising 50 true-false questions based on this program, were elaborated by a National Committee, to help dispensing education at diagnosis of T1D. The questionnaire was completed by 2933 T1D patients (49% girls, 51% boys; 14.1 ± 2.5 year), 2180 mothers and 798 fathers, in 115 pediatric centers. Associations between DKS score (number of correct answers), glycated hemoglobin (HbA1c) and sociofamilial characteristics were assessed.

Results: DKS score increased with age, and was higher in girls than in boys and in mothers than in fathers; it correlated strongly between adolescents and their own parents; it was higher when adolescents had previously participated in diabetes camp and when parents had higher academic levels. HbA1c decreased significantly with parents' higher DKS score and academic level, and when both parents lived together. Mean adolescent DKS score was significantly higher in patients with HbA1c below 8% or 8.5% than for patients with HbA1c above these thresholds.

Conclusion: A large survey in T1D children and adolescents and their parents showed associations between DKS and glycemic control, and the major role of sociofamilial factors.
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http://dx.doi.org/10.1111/pedi.12458DOI Listing
November 2017

Bone imaging findings in genetic and acquired lipodystrophic syndromes: an imaging study of 24 cases.

Skeletal Radiol 2016 Nov 8;45(11):1495-506. Epub 2016 Sep 8.

Rheumatology Department, Université Paris 06, DHU i2B, AP-HP, Saint-Antoine Hospital, 184, rue du Faubourg Saint-Antoine, 75012, Paris, France.

Objective: To describe the bone imaging features of lipodystrophies in the largest cohort ever published.

Materials And Methods: We retrospectively examined bone imaging data in 24 patients with lipodystrophic syndromes. Twenty-two had genetic lipodystrophy: 12/22 familial partial lipodystrophy (FPLD) and 10/22 congenital generalized lipodystrophy (CGL), 8 with AGPAT2-linked CGL1 and 2 with seipin-linked CGL2. Two patients had acquired generalized lipodystrophy (AGL) in a context of non-specific autoimmune disorders. Skeletal radiographs were available for all patients, with radiographic follow-up for two. Four patients with CGL1 underwent MRI, and two of them also underwent CT.

Results: Patients with FPLD showed non-specific degenerative radiographic abnormalities. Conversely, CGL patients showed three types of specific radiographic alterations: diffuse osteosclerosis (in 7 patients, 6 with CGL1 and 1 with CGL2), well-defined osteolytic lesions sparing the axial skeleton (7 CGL1 and 1 CGL2), and pseudo-osteopoikilosis (4 CGL1). Pseudo-osteopoikilosis was the sole bone abnormality observed in one of the two patients with AGL. Osteolytic lesions showed homogeneous low signal intensity (SI) on T1-weighted and high SI on T2-weighted MR images. Most of them were asymptomatic, although one osteolytic lesion resulted in a spontaneous knee fracture and secondary osteoarthritis in a patient with CGL1. MRI also showed diffuse fatty bone marrow alterations in patients with CGL1, with intermediate T1 and high T2 SI, notably in radiographically normal areas.

Conclusions: The three types of peculiar imaging bone abnormalities observed in generalized lipodystrophic syndromes (diffuse osteosclerosis, lytic lesions and/or pseudo-osteopoikilosis) may help clinicians with an early diagnosis in pauci-symptomatic patients.
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http://dx.doi.org/10.1007/s00256-016-2457-9DOI Listing
November 2016

A unique CD8(+) T lymphocyte signature in pediatric type 1 diabetes.

J Autoimmun 2016 09 16;73:54-63. Epub 2016 Jun 16.

Institut National de la Sante et de la Recherche Médicale, Unité 1151, 75015 Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Faculté de médecine, 75015 Paris, France; Centre National de la Recherche Scientifique, UMR8253, 75015 Paris, France. Electronic address:

Human type 1 diabetes results from a destructive auto-reactive immune response in which CD8(+) T lymphocytes play a critical role. Given the intense ongoing efforts to develop immune intervention to prevent and/or cure the disease, biomarkers suitable for prediction of disease risk and progress, as well as for monitoring of immunotherapy are required. We undertook separate multi-parameter analyses of single naïve and activated/memory CD8(+) T lymphocytes from pediatric and adult patients, with the objective of identifying cellular profiles associated with onset of type 1 diabetes. We observe global perturbations in gene and protein expression and in the abundance of T cell populations characterizing pediatric but not adult patients, relative to age-matched healthy individuals. Pediatric diabetes is associated with a unique population of CD8(+) T lymphocytes co-expressing effector (perforin, granzyme B) and regulatory (transforming growth factor β, interleukin-10 receptor) molecules. This population persists after metabolic normalization and is especially abundant in children with high titers of auto-antibodies to glutamic acid decarboxylase and with elevated HbA1c values. These findings highlight striking differences between pediatric and adult type 1 diabetes, indicate prolonged large-scale perturbations in the CD8(+) T cell compartment in the former, and suggest that CD8(+)CD45RA(-) T cells co-expressing effector and regulatory factors are of interest as biomarkers in pediatric type 1 diabetes.
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http://dx.doi.org/10.1016/j.jaut.2016.06.003DOI Listing
September 2016

Insulin regimens, diabetes knowledge, quality of life, and HbA1c in children and adolescents with type 1 diabetes.

Pediatr Diabetes 2017 08 10;18(5):340-347. Epub 2016 May 10.

Endocrinologie, Gynécologie et Diabétologie Pédiatrique, Hôpital Necker, Paris, France.

Objectives: To further describe the changes in insulin therapy regimens and hemoglobin A1c (HbA1c) in children and adolescents with type 1 diabetes, and their associations with diabetes knowledge and quality of life.

Research Design And Methods: The study included 4293 children and adolescents (12.9 ± 2.6 yr, diabetes >1 yr) attending AJD (Aide aux Jeunes Diabétiques) summer camps between 2009 and 2014. The distribution of insulin regimens and associations between HbA1c, therapeutic regimens, diabetes knowledge (AJD questionnaire), and Quality of Life (Ingersoll et Marrero, Hvidoere Study Group short version) were assessed.

Results: The percentage of youth treated with insulin pumps increased up to about 45%, basal bolus stabilized around 40%, and other regimens decreased majorly. HbA1c was higher with premixed insulins only regimens (9.05 ± 2.43%), but there was no difference between pump (8.12 ± 1.09%), basal bolus (8.32 ± 1.33%) and two to three injections (8.18 ± 1.28%). Mean HbA1c decreased by 0.014% per year. The percentage of HbA1c <7.5% increased by 1.5% per year, and the percentages of HbA1c >9% or >10% decreased by 4 and 5.5%, changes being greater with the pump. HbA1c was weakly associated with diabetes knowledge, and strongly with general health perception and perception about diabetes.

Conclusion: The percentage of children and adolescents with the highest risk of complications decreased markedly. The distribution of HbA1c better depicts the glycemic control in a population than the mean or the percentage of patients reaching the target (7.5%). HbA1c was more strongly associated with general health perception than with therapeutic regimens and diabetes knowledge.
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http://dx.doi.org/10.1111/pedi.12397DOI Listing
August 2017

Neuropsychological dysfunction and developmental defects associated with genetic changes in infants with neonatal diabetes mellitus: a prospective cohort study [corrected].

Lancet Diabetes Endocrinol 2013 Nov 6;1(3):199-207. Epub 2013 Sep 6.

Department of Genetics, Robert-Debré Teaching Hospital, Assistance Publique-Hôpitaux de Paris, Paris, France; Université Paris Diderot, Sorbonne Paris Cité, Paris, France.

Background: Neonatal diabetes mellitus is a rare genetic form of pancreatic β-cell dysfunction. We compared phenotypic features and clinical outcomes according to genetic subtypes in a cohort of patients diagnosed with neonatal diabetes mellitus before age 1 year, without β-cell autoimmunity and with normal pancreas morphology.

Methods: We prospectively investigated patients from 20 countries referred to the French Neonatal Diabetes Mellitus Study Group from 1995 to 2010. Patients with hyperglycaemia requiring treatment with insulin before age 1 year were eligible, provided that they had normal pancreatic morphology as assessed by ultrasonography and negative tests for β-cell autoimmunity. We assessed changes in the 6q24 locus, KATP-channel subunit genes (ABCC8 and KCNJ11), and preproinsulin gene (INS) and investigated associations between genotype and phenotype, with special attention to extra-pancreatic abnormalities.

Findings: We tested 174 index patients, of whom 47 (27%) had no detectable genetic defect. Of the remaining 127 index patients, 40 (31%) had 6q24 abnormalities, 43 (34%) had mutations in KCNJ11, 31 (24%) had mutations in ABCC8, and 13 (10%) had mutations in INS. We reported developmental delay with or without epilepsy in 13 index patients (18% of participants with mutations in genes encoding KATP channel subunits). In-depth neuropsychomotor investigations were done at median age 7 years (IQR 1-15) in 27 index patients with mutations in KATP channel subunit genes who did not have developmental delay or epilepsy. Developmental coordination disorder (particularly visual-spatial dyspraxia) or attention deficits were recorded in all index patients who had this testing. Compared with index patients who had mutations in KATP channel subunit genes, those with 6q24 abnormalities had specific features: developmental defects involving the heart, kidneys, or urinary tract (8/36 [22%] vs 2/71 [3%]; p=0·002), intrauterine growth restriction (34/37 [92%] vs 34/70 [48%]; p<0·0001), and early diagnosis (median age 5·0 days, IQR 1·0-14·5 vs 45·5 days, IQR 27·2-95·0; p<0·0001). Remission of neonatal diabetes mellitus occurred in 89 (51%) index patients at a median age of 17 weeks (IQR 9·5-39·0; median follow-up 4·7 years, IQR 1·5-12·8). Recurrence was common, with no difference between the groups who had 6q24 abnormalities versus mutations in KATP channel subunit genes (82% vs 86%; p=0·36).

Interpretation: Neonatal diabetes mellitus is often associated with neuropsychological dysfunction and developmental defects that are specific to the underlying genetic abnormality. A multidisciplinary assessment is therefore essential when patients are diagnosed. Features of neuropsychological dysfunction and developmental defects should be tested for in adults with a history of neonatal diabetes mellitus.

Funding: Agence Nationale de la Recherche-Maladies Rares Research Program Grant, the Transnational European Research Grant on Rare Diseases, the Société Francophone du Diabète-Association Française du Diabète, the Association Française du Diabète, Aide aux Jeunes Diabétiques, a CIFRE grant from the French Government, HRA-Pharma, the French Ministry of Education and Research, and the Société Française de Pédiatrie.
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http://dx.doi.org/10.1016/S2213-8587(13)70059-7DOI Listing
November 2013

Changes in insulin therapy regimens over 10 yr in children and adolescents with type 1 diabetes attending diabetes camps.

Pediatr Diabetes 2014 Aug 9;15(5):329-35. Epub 2013 Sep 9.

Pediatric and Adolescent Diabetes, Hôpital Necker-Enfants Malades, Paris, France.

Objective: To describe the changes in insulin therapy regimens of children and adolescents with type 1 diabetes over 10 yr and their correlation with hemoglobin A1c (HbA1c).

Research Design And Methods: The study included 7206 children and adolescents (age 12.8 ± 2.7 yr, more than 1 yr of diabetes duration) admitted in summer camps between 1998 and 2007 (707-896/yr). Based on injection times (breakfast, lunch, afternoon, dinner, bedtime) and insulin types (short, long and premixed; human or analog), 786 different therapeutic combinations were classified in six main types of regimens. The distribution of the different regimens and their correlation with HbA1c were evaluated as a function of year and age.

Results: Over 10 yr, basal bolus increased from 13 to 52% and the pump from <1 to 13%, regimens with two to three injections per day decreased from 50 to 25%, those with only premixed insulins from 33 to 7%, and diverse regimens from 9 to 1%. HbA1c was significantly higher with premixed insulin only, but there were no differences between the other regimens throughout the follow-up. Mean yearly HbA1c (8.21-8.45%) did not show any significant decrease, but the percentage of patients with HbA1c > 9 and 10% decreased significantly, in those treated with two to three injections and the pump, not with basal bolus or premixed only regimens.

Conclusion: A major trend in intensifying insulin treatment in children and adolescents with type 1 diabetes was accompanied by modest improvements in HbA1c. No insulin regimen has shown any better results, except over premixed insulins.
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http://dx.doi.org/10.1111/pedi.12062DOI Listing
August 2014

Recommendations for age-appropriate education of children and adolescents with diabetes and their parents in the European Union.

Pediatr Diabetes 2012 Sep;13 Suppl 16:20-8

Hôpital Necker-Enfants Malades, Université René Descartes, Sorbonne Paris Cité, 149 rue de Sèvres, Paris Cedex 15, France.

Education is the keystone of diabetes care, and structured self-management education is the key to a successful outcome. Existing guidelines provide comprehensive guidance on the various aspects of education and offer general and organizational principles of education, detailed curricula at different ages and stages of diabetes, and recommendations on models, methods, and tools to attain educative objectives. The International Society for Pediatric and Adolescent Diabetes guidelines give the most elaborate and detailed descriptions and recommendations on the practice of education, which other national guidelines address on specific aspects of education and care. The aim of the work package on education developed by Better Control in Paediatric and Adolescent Diabetes in the European Union: Working to Create Centers of Reference (SWEET) project was not to generate new guidelines but to evaluate how the existing guidelines were implemented in some pediatric diabetes reference centers. The SWEET members have completed a questionnaire that elaborates on the many aspects of delivery of education. This survey highlights a profound diversity of practices across centers in Europe, in terms of organization as well as the practices and the content of initial and continuing education. A toolbox is being developed within SWEET to facilitate exchanges on all aspects of education and to establish a process of validation of materials, tools, written structured age-adjusted programs, and evaluation procedures for the education of children and adolescents with diabetes.
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http://dx.doi.org/10.1111/j.1399-5448.2012.00909.xDOI Listing
September 2012

Comorbidity and metabolic context are crucial factors determining neurological sequelae of hypoglycaemia.

Dev Med Child Neurol 2012 Nov 27;54(11):1012-7. Epub 2012 Aug 27.

Neuropediatrics Department, Necker-Enfants Malades Hospital, Paris, France.

Aim: To determine risk factors for neurological sequelae following hypoglycemia.

Method: We analysed the neurological outcome in 164 patients (mean age 10y 10mo, SD 5.9) following hypoglycemia due to three diseases with various metabolic contexts, different ages at onset, and combinations with comorbidity (fever/infection, hypoxia/ischemia): glycogen storage disease type I (GSDI) (21 patients, mean age at first hypoglycemic episode 3.8mo, SD 3.5); fatty acid β-oxidation defects (FAOD) (29 patients, mean age at first hypoglycemic episode 14.8mo, SD 12.6); and hyperinsulinism (HIns) (114 patients, mean age at first hypoglycemic episode 2.3mo, SD 4.7).

Results: Risk factors of poor neurological outcome were aetiology (p<0.006), comorbidity (p<0.001), and prolonged convulsions (p<0.001). Ordinal logistic regression showed that comorbidity (p<0.001) and status epilepticus (p=0.002) were the main determinants of sequelae. Asymptomatic hypoglycemia did not lead to sequelae, whatever the aetiology. Age was not correlated to sequelae, whatever the aetiology. The highest prevalence of hypoglycemic sequelae was found in FAOD and HIns combined with comorbidity, the lowest in GSDI (p<0.001) in which hypoglycemia is often asymptomatic, associated with increased plasma lactate, and rarely combined with comorbidity.

Interpretation: Hypoglycemia is severely deleterious for the brain in the context of fever/infection and/or hypoxia/ischemia, and status epilepticus. The metabolic context providing alternative fuels may improve neurological outcome.
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http://dx.doi.org/10.1111/j.1469-8749.2012.04400.xDOI Listing
November 2012

ZnT8 is a major CD8+ T cell-recognized autoantigen in pediatric type 1 diabetes.

Diabetes 2012 Jul 14;61(7):1779-84. Epub 2012 May 14.

INSERM, Unité 1013, Paris, France.

Type 1 diabetes results from the destruction of β-cells by an autoimmune T-cell response assisted by antigen-presenting B cells producing autoantibodies. CD8(+) T-cell responses against islet cell antigens, thought to play a central role in diabetes pathogenesis, can be monitored using enzyme-linked immunosorbent spot (ELISpot) assays. However, such assays have been applied to monitoring of adult patients only, leaving aside the large and increasing pediatric patient population. The objective of this study was twofold: 1) to develop a CD8(+) T-cell interferon-γ ELISpot assay for pediatric patients and 2) to determine whether zinc transporter 8 (ZnT8), a recently described target of autoantibodies in a majority of patients, is also recognized by autoreactive CD8(+) T cells. Using DNA immunization of humanized mice, we identified nine HLA-A2-restricted ZnT8 epitopes. Among 36 HLA-A2(+) children with diabetes, 29 responded to ZnT8 epitopes, whereas only 3 of 16 HLA-A2(+) control patients and 0 of 17 HLA-A2(-) control patients responded. Some single ZnT8 epitopes performed as well as the group of epitopes in discriminating between patients and control individuals. Thus, ZnT8 is a major CD8(+) T-cell autoantigen, and ELISpot assays display similar performance in adult and pediatric type 1 diabetes.
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http://dx.doi.org/10.2337/db12-0071DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3379659PMC
July 2012

GAD65 antigen therapy in recently diagnosed type 1 diabetes mellitus.

N Engl J Med 2012 Feb;366(5):433-42

Division of Pediatrics, Department of Clinical and Experimental Medicine, Linköping University, 58185 Linköping, Sweden.

Background: The 65-kD isoform of glutamic acid decarboxylase (GAD65) is a major autoantigen in type 1 diabetes. We hypothesized that alum-formulated GAD65 (GAD-alum) can preserve beta-cell function in patients with recent-onset type 1 diabetes.

Methods: We studied 334 patients, 10 to 20 years of age, with type 1 diabetes, fasting C-peptide levels of more than 0.3 ng per milliliter (0.1 nmol per liter), and detectable serum GAD65 autoantibodies. Within 3 months after diagnosis, patients were randomly assigned to receive one of three study treatments: four doses of GAD-alum, two doses of GAD-alum followed by two doses of placebo, or four doses of placebo. The primary outcome was the change in the stimulated serum C-peptide level (after a mixed-meal tolerance test) between the baseline visit and the 15-month visit. Secondary outcomes included the glycated hemoglobin level, mean daily insulin dose, rate of hypoglycemia, and fasting and maximum stimulated C-peptide levels.

Results: The stimulated C-peptide level declined to a similar degree in all study groups, and the primary outcome at 15 months did not differ significantly between the combined active-drug groups and the placebo group (P=0.10). The use of GAD-alum as compared with placebo did not affect the insulin dose, glycated hemoglobin level, or hypoglycemia rate. Adverse events were infrequent and mild in the three groups, with no significant differences.

Conclusions: Treatment with GAD-alum did not significantly reduce the loss of stimulated C peptide or improve clinical outcomes over a 15-month period. (Funded by Diamyd Medical and the Swedish Child Diabetes Foundation; ClinicalTrials.gov number, NCT00723411.).
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http://dx.doi.org/10.1056/NEJMoa1107096DOI Listing
February 2012

Glucose metabolism in 105 children and adolescents after pancreatectomy for congenital hyperinsulinism.

Diabetes Care 2012 Feb 21;35(2):198-203. Epub 2011 Dec 21.

Pediatric Endocrinology and Diabetes, Hôpital Necker-Enfants Malades, Université Paris Descartes Sorbonne Paris cité, Paris, France.

Objective: To describe the long-term metabolic outcome of children with congenital hyperinsulinism after near-total or partial elective pancreatectomy.

Research Design And Methods: Patients (n = 105: 58 diffuse and 47 focal congenital hyperinsulinism) received operations between 1984 and 2006. Follow-up consisted of periodic measurements of pre- and postprandial plasma glucose over 24 h, OGTT, and IVGTT. Cumulative incidence of hypo- or hyperglycemia/insulin treatment was estimated by Kaplan-Meier analysis.

Results: After near-total pancreatectomy, 59% of children with diffuse congenital hyperinsulinism still presented mild or asymptomatic hypoglycemia that responded to medical treatments and disappeared within 5 years. One-third of the patients had both preprandial hypoglycemia and postprandial hyperglycemia. Hyperglycemia was found in 53% of the patients immediately after surgery; its incidence increased regularly to 100% at 13 years. The cumulative incidence of insulin-treated patients was 42% at 8 years and reached 91% at 14 years, but the progression to insulin dependence was very variable among the patients. Plasma insulin responses to IVGTT and OGTT correlated well with glycemic alterations. In focal congenital hyperinsulinism, hypoglycemia or hyperglycemia were rare, mild, and transient.

Conclusions: Patients with focal congenital hyperinsulinism are cured of hypoglycemia after limited surgery, while the outcome of diffuse congenital hyperinsulinism is very variable after near-total pancreatectomy. The incidence of insulin-dependent diabetes is very high in early adolescence.
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http://dx.doi.org/10.2337/dc11-1296DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3263917PMC
February 2012

High prevalence of hirsutism and menstrual disorders in obese adolescent girls and adolescent girls with type 1 diabetes mellitus despite different hormonal profiles.

Eur J Endocrinol 2012 Feb 29;166(2):307-16. Epub 2011 Nov 29.

Paediatric Endocrinology and Diabetes Unit, Assistance Publique-Hôpitaux de Paris, Université Paris Descartes, Hôpital Necker-Enfants Malades, 149 rue de Sèvres, 75015 Paris, France.

Objectives: To compare the pubertal development, the hormonal profiles and the prevalence of hirsutism and menstrual disorders in obese adolescent girls and adolescent girls with type 1 diabetes mellitus (T1DM).

Methods: Data were collected from 96 obese adolescent girls and 78 adolescent girls with T1DM at Tanner stage IV or V, whose ages ranged between 11.9 and 17.9 years.

Results: High prevalence of hirsutism and menstrual disorder was found in the obese adolescent girls (36.5 and 42% respectively) and the adolescent girls with T1DM (21 and 44% respectively). The obese girls were significantly younger at pubarche, thelarche and menarche than the girls with T1DM. Hirsutism in the obese girls and those with T1DM was associated with hyperandrogenaemia and a raised free androgen index (FAI). When the cause of the raised FAI was investigated in both the groups of girls with hirsutism, the raised FAI in the obese girls was due to low serum sex hormone-binding globulin (SHBG) levels. In contrast, the raised FAI of the girls with T1DM and hirsutism was due to hyperandrogenaemia. Menstrual disorders in the T1DM girls were associated also with hyperandrogenaemia unlike obese girls.

Conclusions: Hirsutism and menstrual disorders are common in obese adolescent girls and adolescent girls with T1DM. Although hyperandrogenaemia is present in both groups of girls, the androgenic profiles of the two groups differ. The hyperandrogenaemia in the obese girls is primarily due to their decreased serum SHBG levels, whereas the hyperandrogenaemia in the girls with T1DM is due to their increased androgen production.
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http://dx.doi.org/10.1530/EJE-11-0670DOI Listing
February 2012

Congenital hyperinsulinism: current trends in diagnosis and therapy.

Orphanet J Rare Dis 2011 Oct 3;6:63. Epub 2011 Oct 3.

Centre de Référence des Maladies Héréditaires du Métabolisme de l'Enfant et l'Adulte, AP-HP Hôpital Necker-Enfants Malades, Université Paris Descartes, Paris, France.

Congenital hyperinsulinism (HI) is an inappropriate insulin secretion by the pancreatic β-cells secondary to various genetic disorders. The incidence is estimated at 1/50, 000 live births, but it may be as high as 1/2, 500 in countries with substantial consanguinity. Recurrent episodes of hyperinsulinemic hypoglycemia may expose to high risk of brain damage. Hypoglycemias are diagnosed because of seizures, a faint, or any other neurological symptom, in the neonatal period or later, usually within the first two years of life. After the neonatal period, the patient can present the typical clinical features of a hypoglycemia: pallor, sweat and tachycardia. HI is a heterogeneous disorder with two main clinically indistinguishable histopathological lesions: diffuse and focal. Atypical lesions are under characterization. Recessive ABCC8 mutations (encoding SUR1, subunit of a potassium channel) and, more rarely, recessive KCNJ11 (encoding Kir6.2, subunit of the same potassium channel) mutations, are responsible for most severe diazoxide-unresponsive HI. Focal HI, also diazoxide-unresponsive, is due to the combination of a paternally-inherited ABCC8 or KCNJ11 mutation and a paternal isodisomy of the 11p15 region, which is specific to the islets cells within the focal lesion. Genetics and 18F-fluoro-L-DOPA positron emission tomography (PET) help to diagnose diffuse or focal forms of HI. Hypoglycemias must be rapidly and intensively treated to prevent severe and irreversible brain damage. This includes a glucose load and/or a glucagon injection, at the time of hypoglycemia, to correct it. Then a treatment to prevent the recurrence of hypoglycemia must be set, which may include frequent and glucose-enriched feeding, diazoxide and octreotide. When medical and dietary therapies are ineffective, or when a focal HI is suspected, surgical treatment is required. Focal HI may be definitively cured when the partial pancreatectomy removes the whole lesion. By contrast, the long-term outcome of diffuse HI after subtotal pancreatectomy is characterized by a high risk of diabetes, but the time of its onset is hardly predictable.
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http://dx.doi.org/10.1186/1750-1172-6-63DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3199232PMC
October 2011

Congenital hyperinsulinism.

Early Hum Dev 2010 May 13;86(5):287-94. Epub 2010 Jun 13.

Hospital Necker-Enfants Malades, Paris, France.

Congenital hyperinsulinism (CHI or HI) is a condition leading to recurrent hypoglycemia due to an inappropriate insulin secretion by the pancreatic islet beta cells. HI has two main characteristics: a high glucose requirement to correct hypoglycemia and a responsiveness of hypoglycemia to exogenous glucagon. HI is usually isolated but may be rarely part of a genetic syndrome (e.g. Beckwith-Wiedemann syndrome, Sotos syndrome etc.). The severity of HI is evaluated by the glucose administration rate required to maintain normal glycemia and the responsiveness to medical treatment. Neonatal onset HI is usually severe while late onset and syndromic HI are generally responsive to a medical treatment. Glycemia must be maintained within normal ranges to avoid brain damages, initially with glucose administration and glucagon infusion then, once the diagnosis is set, with specific HI treatment. Oral diazoxide is a first line treatment. In case of unresponsiveness to this treatment, somatostatin analogues and calcium antagonists may be added, and further investigations are required for the putative histological diagnosis: pancreatic (18)F-fluoro-L-DOPA PET-CT and molecular analysis. Indeed, focal forms consist of a focal adenomatous hyperplasia of islet cells, and will be cured after a partial pancreatectomy. Diffuse HI involves all the pancreatic beta cells of the whole pancreas. Diffuse HI resistant to medical treatment (octreotide, diazoxide, calcium antagonists and continuous feeding) may require subtotal pancreatectomy which post-operative outcome is unpredictable. The genetics of focal islet-cells hyperplasia associates a paternally inherited mutation of the ABCC8 or the KCNJ11 genes, with a loss of the maternal allele specifically in the hyperplasic islet cells. The genetics of diffuse isolated HI is heterogeneous and may be recessively inherited (ABCC8 and KCNJ11) or dominantly inherited (ABCC8, KCNJ11, GCK, GLUD1, SLC16A1, HNF4A and HADH). Syndromic HI are always diffuse form and the genetics depend on the syndrome. Except for HI due to potassium channel defect (ABCC8 and KCNJ11), most of these HI are sensitive to diazoxide. The main points sum up the management of HI: i) prevention of brain damages by normalizing glycemia and ii) screening for focal HI as they may be definitively cured after a limited pancreatectomy.
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http://dx.doi.org/10.1016/j.earlhumdev.2010.05.003DOI Listing
May 2010

Resistance to leptin-replacement therapy in Berardinelli-Seip congenital lipodystrophy: an immunological origin.

Eur J Endocrinol 2010 Jun 17;162(6):1083-91. Epub 2010 Mar 17.

Unité INSERM U690, Hôpital Robert Debré, 48 Boulevard Sérurier, Paris, France.

Context: Recently, in a 4-month proof-of-concept trial, beneficial metabolic effects were reported in non-diabetic children with Berardinelli-Seip congenital lipodystrophy (BSCL); this information prompted us to hypothesize that long-term leptin-replacement therapy might improve or reverse the early complications of the disease in these patients.

Patients And Methods: A 28-month trial was implemented in eight patients. Efficacy assessment was based on a decrease in serum triglyceride concentrations, and/or a decrease in liver volume and/or an increase in insulin sensitivity of at least 30% respectively. The response was defined as follows: total (3/3 positive criteria), partial (1 or 2/3), or negative (0/3). Anti-leptin antibodies were measured with a radiobinding assay, and a neutralizing effect was assessed in primary cultures of embryonic neurons incubated with an apoptotic agent (N-methyl-D-aspartate) and the patient serum, with or without leptin.

Results: A negative or partial response to treatment was observed in five of eight patients even when leptin dosages were increased. A displaceable leptin binding was detectable in all patients after 2 months of treatment. At 28 months, binding was higher in the patients with a negative response than in the total responders, and it paralleled both the increase in leptin dosage and serum leptin concentrations. Co-incubation of embryonic neurons with serum from two patients with a negative response inhibited the neuroprotective effect of leptin.

Conclusion: Under leptin therapy, patients with BSCL may develop a resistance to leptin, which could be partly of immunological origin, blunting the previously reported beneficial effects.
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http://dx.doi.org/10.1530/EJE-09-1027DOI Listing
June 2010

Effect of insulin detemir dose frequency on clinical outcomes in patients with diabetes in PREDICTIVE.

Adv Ther 2009 May 2;26(5):535-51. Epub 2009 Jun 2.

Department of Endocrinology-Diabetes, CHRU, Lille, France.

Introduction: The aim was to compare clinical outcomes by different dosing frequencies of insulin detemir (detemir) used over 52 weeks in various regimens.

Methods: This analysis involved French patients enrolled in PREDICTIVE (a large-scale, multinational, observational study of empirical use of detemir in everyday clinical practice) for whom data have been collected over 52 weeks. Three cohorts were considered: patients with type 1 diabetes; patients with type 2 diabetes using detemir in a basal insulin plus oral antidiabetic drug (OAD) regimen; patients with type 2 diabetes using detemir as part of basal-bolus insulin therapy. In each cohort, data were stratified according to detemir dosing frequency at the beginning and end of 52 weeks: once daily (o.d.) at the beginning and end; twice daily (b.i.d.) at the beginning and end; o.d. at the beginning, but b.i.d. at the end. Endpoints assessed included glycated hemoglobin, fasting plasma glucose, hypoglycemia, weight, and insulin dose.

Results: There were improvements in glycemic control and tolerability in all subgroups. Patients completing on o.d. dosing tended to have better outcomes than those completing on b.i.d. dosing in all cohorts, and o.d. administration was associated with lower insulin dosing. There was little evidence that switching from o.d. to b.i.d. dosing influenced outcomes other than insulin dose. However, there were some baseline differences between subgroups selected for o.d. and b.i.d. dosing that might have influenced outcomes: many patients appeared to have been continued on previous basal dosing frequencies; for others, b.i.d. detemir dosing seemed to be used to intensify previous therapy.

Conclusions: With the caveat that empirical choices of dose frequency were made, this analysis shows that empirical use of o.d. detemir produces results at least as good as empirical use of b.i.d. detemir in basal-bolus-treated type 1 and type 2 diabetes, and in basal plus OAD-treated type 2 diabetes.
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http://dx.doi.org/10.1007/s12325-009-0033-6DOI Listing
May 2009

Developmental methylation program and concerted expression of Stx11 in mouse tissues.

Mamm Genome 2009 Mar 24;20(3):131-9. Epub 2009 Jan 24.

INSERM U781, Université René Descartes Paris, Hôpital Necker Enfants Malades Clinique Maurice Lamy, 161 rue de Sèvres, 75743, Paris Cedex 15, France.

The human 6q24 region is involved in growth and development, transient neonatal diabetes (TND), cancer, and metabolic dysfunction. To further characterize this region, the developmental status of DNA methylation and expression of Zac1 and Stx11 genes located within the mouse 10A1 region ortholog of human 6q24 were determined. In mice, imprinted Zac1 and Stx11 were highly expressed at the end of fetal development but downregulated at 4 and 11 weeks in brain, pancreas, and heart. Postnatal Zac1 downregulation was independent from promoter methylation of the expressed allele, suggesting the mediation of age-dependent chromatin remodeling. Stx11 nonpromoter CpG island was methylated de novo from E18 to 1 year with tissue-specific kinetics. The high conservation in vertebrates of Stx11 CpG2 is suggestive of an important regulatory function in age-related regional epigenetic state and/or chromatin configuration. Stx11 alleles were unequally expressed in F1 mice tissues, reflecting the influence of cis-regulatory factors on its expression. These data suggest the presence of a methylation domain and a coordinated gene expression pattern in multiple tissues. Methylation variation and allelic regulation of expression may underlie genetic diversity and contribute to disease susceptibility at the 6q24 locus in humans.
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http://dx.doi.org/10.1007/s00335-008-9162-5DOI Listing
March 2009

Long-term follow-up of oral glucose tolerance test-derived glucose tolerance and insulin secretion and insulin sensitivity indexes in subjects with glucokinase mutations (MODY2).

Diabetes Care 2008 Jul 14;31(7):1321-3. Epub 2008 Apr 14.

Department of Pediatric Diabetology, AP-HP Hôpital Necker-Enfants Malades, Paris, France.

Objective: We investigated the natural history of glucokinase (GCK)-related maturity-onset diabetes of the young type 2 (MODY2), notably the factors associated with deterioration of hyperglycemia over time.

Research Design And Methods: We report an 11-year follow-up of glucose tolerance and indexes of insulin secretion and insulin sensitivity derived from oral glucose tolerance tests in 33 MODY2 subjects.

Results: The variation between tests of glucose tolerance (expressed as the area under the glucose curve) was 6.9 +/- 3.2% (mean +/- SEM), but individual results ranged from -20 to 61%. Deterioration of glucose tolerance between tests was associated with decreased insulin sensitivity, while insulin secretion remained stable.

Conclusions: Glucose tolerance can remain stable over many years in subjects with MODY2 due to the relative stability of the GCK-related beta-cell defect. However, the development of insulin resistance may have an important role in the deterioration of the glucose tolerance and in the long-term evolution of the disorder.
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http://dx.doi.org/10.2337/dc07-2017DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2453674PMC
July 2008

Glucose tolerance and insulin secretion, morbidity, and death in patients with cystic fibrosis.

J Pediatr 2008 Apr 26;152(4):540-5, 545.e1. Epub 2007 Nov 26.

Department of Pediatric Diabetology, Bichat Hospital, Paris, France.

Objectives: To describe the history, mechanisms, and consequences of cystic fibrosis (CF)-related diabetes, from childhood to early adulthood.

Study Design: Pancreatic beta-cell function was estimated from the plasma insulin/glucose ratios during oral glucose tolerance test (total area under the curve and deltaI(30-0min)/G(30min), homeostasis model assessment [HOMA]%B), insulin sensitivity with the HOMA%S index, in 237 children with CF (109 boys, 128 girls). Progression of glucose metabolism abnormalities was evaluated by analysis for interval censored data; rates of pulmonary transplantation and death by Kaplan-Meier analysis.

Results: Impaired glucose tolerance was found in 20% of patients at 10 years, 50% at 15 years, 75% at 20 years, 82% at 30 years; for diabetes, >20% at 15 year, 45% at 20 years, 70% at 30 years; for insulin treatment, 30% at 20 years, 40% at 30 years. Early impairment was associated with lower survival rates and higher rates of lung transplantation. The area under the curve(glucose) correlated with decreased body mass index and height. Decrease in early insulin secretion (deltaI(30-0min)/G(30min)) was associated with impaired glucose tolerance, in all estimates of insulin secretion with diabetes. HOMA%S did not differ between the groups. Increased inflammation correlated with insulin resistance and impaired glucose tolerance.

Conclusions: CF-related diabetes, mainly because of beta-cell deficiency, is frequent early in life and associated with impaired nutritional state and growth, increased rates of terminal respiratory failure, and death.
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http://dx.doi.org/10.1016/j.jpeds.2007.09.025DOI Listing
April 2008

What's new in metabolic and genetic hypoglycaemias: diagnosis and management.

Eur J Pediatr 2008 Mar 3;167(3):257-65. Epub 2007 Oct 3.

Metabolic Department and Reference Centre for Metabolic Diseases, Necker-Enfants Malades Hospital, 149, Rue des Sèvres, 75015 Paris, France,

Hypoglycaemia in children can be a life-threatening situation that needs to be assessed rigorously in order to treat efficiently and avoid relapse that can be responsible for cerebral damage. The diagnosis of impairment in glucose homeostasis requires the knowledge of the mechanisms regulating blood glucose concentration. The clinical history and presentation, when available, especially the timing of hypoglycaemia with respect to the last meal and some simple clinical and biological tests may allow diagnosing the vast majority of patients presenting with hypoglycaemia. Recently, new metabolic and endocrinologic genetic causes of hypoglycaemia have been identified that may give new insight to the complex mechanisms of glucose regulation and thus contribute to the discovery of new genes regulating glucose homeostasis. New diagnostic tests such as the 18-fluoro-Dopa PET-scan have also been recently developed.
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http://dx.doi.org/10.1007/s00431-007-0600-2DOI Listing
March 2008

Molecular mechanisms of neonatal hyperinsulinism.

Horm Res 2006 26;66(6):289-96. Epub 2006 Sep 26.

INSERM U654 and Department of Genetics, Hôpital Henri Mondor, Créteil, France.

Congenital hyperinsulinism (CHI), characterized by profound hypoglycaemia related to inappropriate insulin secretion, may be associated histologically with either diffuse insulin hypersecretion or focal adenomatous hyperplasia, which share a similar clinical presentation, but result from different molecular mechanisms. Whereas diffuse CHI is of autosomal recessive, or less frequently of autosomal dominant, inheritance, focal CHI is sporadic. The most common mechanism underlying CHI is dysfunction of the pancreatic ATP-sensitive potassium channel (K(+)(ATP)). The two subunits of the K(+)(ATP) channel are encoded by the sulfonylurea receptor gene (SUR1 or ABCC8) and the inward-rectifying potassium channel gene (KIR6.2 or KCNJ11), both located in the 11p15.1 region. Germ-line, paternally inherited, mutations of the SUR1 or KIR6.2 genes, together with somatic maternal haplo-insufficiency for 11p15.5, were shown to result in focal CHI. Diffuse CHI results from germ-line mutations in the SUR1 or KIR6.2 genes, but also from mutations in several other genes, namely glutamate dehydrogenase (with associated hyperammonaemia), glucokinase, short-chain L-3-hydroxyacyl-CoA dehydrogenase, and insulin receptor gene. Hyperinsulinaemic hypoglycaemia may be observed in several overlapping syndromes, such as Beckwith-Wiedemann syndrome (BWS), Perlman syndrome, and, more rarely, Sotos syndrome. Mosaic genome-wide paternal isodisomy has recently been reported in patients with clinical signs of BWS and CHI. The primary causes of CHI are genetically heterogeneous and have not yet been completely unveiled. However, secondary causes of hyperinsulinism have to be considered such as fatty acid oxidation deficiency, congenital disorders of glycosylation and factitious hypoglycaemia secondary to Munchausen by proxy syndrome.
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http://dx.doi.org/10.1159/000095938DOI Listing
December 2006

Switching from insulin to oral sulfonylureas in patients with diabetes due to Kir6.2 mutations.

N Engl J Med 2006 Aug;355(5):467-77

Institute of Biomedical and Clinical Sciences, Peninsula Medical School, Exeter, United Kingdom.

Background: Heterozygous activating mutations in KCNJ11, encoding the Kir6.2 subunit of the ATP-sensitive potassium (K(ATP)) channel, cause 30 to 58 percent of cases of diabetes diagnosed in patients under six months of age. Patients present with ketoacidosis or severe hyperglycemia and are treated with insulin. Diabetes results from impaired insulin secretion caused by a failure of the beta-cell K(ATP) channel to close in response to increased intracellular ATP. Sulfonylureas close the K(ATP) channel by an ATP-independent route.

Methods: We assessed glycemic control in 49 consecutive patients with Kir6.2 mutations who received appropriate doses of sulfonylureas and, in smaller subgroups, investigated the insulin secretory responses to intravenous and oral glucose, a mixed meal, and glucagon. The response of mutant K(ATP) channels to the sulfonylurea tolbutamide was assayed in xenopus oocytes.

Results: A total of 44 patients (90 percent) successfully discontinued insulin after receiving sulfonylureas. The extent of the tolbutamide blockade of K(ATP) channels in vitro reflected the response seen in patients. Glycated hemoglobin levels improved in all patients who switched to sulfonylurea therapy (from 8.1 percent before treatment to 6.4 percent after 12 weeks of treatment, P<0.001). Improved glycemic control was sustained at one year. Sulfonylurea treatment increased insulin secretion, which was more highly stimulated by oral glucose or a mixed meal than by intravenous glucose. Exogenous glucagon increased insulin secretion only in the presence of sulfonylureas.

Conclusions: Sulfonylurea therapy is safe in the short term for patients with diabetes caused by KCNJ11 mutations and is probably more effective than insulin therapy. This pharmacogenetic response to sulfonylureas may result from the closing of mutant K(ATP) channels, thereby increasing insulin secretion in response to incretins and glucose metabolism. (ClinicalTrials.gov number, NCT00334711 [ClinicalTrials.gov].).
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http://dx.doi.org/10.1056/NEJMoa061759DOI Listing
August 2006

The Knudson's two-hit model and timing of somatic mutation may account for the phenotypic diversity of focal congenital hyperinsulinism.

J Clin Endocrinol Metab 2006 Oct 1;91(10):4118-23. Epub 2006 Aug 1.

INSERM U654, and Department of Genetics, Hôpital Henri Mondor, 51 Avenue du Marechal de Lattre de Tassigny, 94010 Creteil Cedex, France.

Background: Congenital hyperinsulinism (CHI) is associated with focal hyperplasia of endocrine tissue in 40-65% of patients. Focal CHI is sporadic and is caused by a germline, paternally inherited, mutation of the SUR1 (ABCC8) or KIR6.2 (KCNJ11) genes (encoding subunits of the pancreatic ATP-dependent potassium channel) together with somatic maternal haploinsufficiency for 11p15.5. Plurifocal or large forms of focal CHI are a cause of apparent failure of surgery, and their underlying mechanism has not been thoroughly investigated.

Patients: We here report two patients with bifocal CHI as evidenced by relapsing hypoglycemia after removal of the first focal lesion and the detection of a second, distinct, focal adenomatous hyperplasia during later surgery (patients 1 and 2) and a patient with a giant focal lesion involving the major part of the pancreas (patient 3).

Results: In the three patients, a germline, paternally inherited, mutation of SUR1 was found. In patients 1 and 2, haploinsufficiency for the maternal 11p15.5 region resulted from a somatic deletion specific for each of the focal lesions, as shown by the diversity of deletion break points. In patient 3, an identical somatic maternal 11p15 deletion demonstrated by similar break points was shown in two independent lesion samples, suggesting a very early event during pancreas embryogenesis.

Conclusion: Individual patients with focal hyperinsulinism may have more than one focal pancreatic lesion due to separate somatic maternal deletion of the 11p15 region. These patients and those with solitary focal lesions may follow the two-hit model described by Knudson. The stage of embryogenesis at which the somatic event occurs may account for the observed histological diversity (early event giant lesion, later event small lesion).
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http://dx.doi.org/10.1210/jc.2006-0397DOI Listing
October 2006

KCNJ11 activating mutations are associated with developmental delay, epilepsy and neonatal diabetes syndrome and other neurological features.

Eur J Hum Genet 2006 Jul 3;14(7):824-30. Epub 2006 May 3.

Diabetes Research Laboratories, Oxford Centre for Diabetes Endocrinology and Metabolism, University of Oxford, UK.

Heterozygous activating mutations in the gene encoding for the ATP-sensitive potassium channel subunit Kir6.2 (KCNJ11) have recently been shown to be a common cause of permanent neonatal diabetes. Kir6.2 is expressed in muscle, neuron and brain as well as the pancreatic beta-cell, so patients with KCNJ11 mutations could have a neurological phenotype in addition to their diabetes. It is proposed that some patients with KCNJ11 mutations have neurological features that are part of a discrete neurological syndrome termed developmental Delay, Epilepsy and Neonatal Diabetes (DEND), but there are also neurological consequences of chronic or acute diabetes. We identified KCNJ11 mutations in four of 10 probands with permanent neonatal diabetes and one affected parent; this included the novel C166F mutation and the previously described V59M and R201H. Four of the five patients with mutations had neurological features: the patient with the C166F mutation had marked developmental delay, severe generalised epilepsy, hypotonia and muscle weakness; mild developmental delay was present in the patient with the V59M mutation; one patient with the R201H mutation had acute and chronic neurological consequences of cerebral oedema and another had diabetic neuropathy from chronic hyperglycaemia. In conclusion, the clinical features in these patients support the existence of a discrete neurological syndrome with KCNJ11 mutations. The severe DEND syndrome was seen with the novel C166F mutation and mild developmental delay with the V59M mutation. These features differ markedly from the neurological consequences of acute or chronic diabetes.
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http://dx.doi.org/10.1038/sj.ejhg.5201629DOI Listing
July 2006