Position statement on the diagnosis and management of congenital pituitary deficiency in adults: the French National Diagnosis and Treatment Protocol (NDTP)

Pituitary deficiency, or hypopituitarism, is a rare chronic disease. It is defined by insufficient synthesis of one or more pituitary hormones (growth hormone, TSH, ACTH, LH-FSH, prolactin), whether or not associated with arginine vasopressin deficiency (formerly known as diabetes insipidus). In adult patients, it is usually acquired (notably during childhood), but can also be congenital, due to abnormal pituitary development. The present study focuses on congenital pituitary deficiency in adults, from diagnosis to follow-up, including special situations such as pregnancy or the elderly. The clinical presentation is highly variable, ranging from isolated deficit to multiple deficits, which may be part of a syndromic form or not. Diagnosis is based on a combination of clinical, biological (assessment of all hormonal axes), radiological (brain and hypothalamic-pituitary MRI) and genetic factors. Treatment consists in hormonal replacement therapy, adapted according to the period of life and the deficits, which may be progressive. Comorbidities, risk of complications and acute decompensation, and the impact on fertility and quality of life all require adaptative multidisciplinary care and long-term monitoring.

Iatrogenic endocrine complications of lithium therapy

Lithium is a cation, similar to sodium and potassium, affecting ion transport. It is used in the medical field as a treatment of bipolar disorders. The main endocrine complications of lithium treatment affect thyroid and parathyroid glands, in association with renal complications. Thyroid adverse effects, which are more frequent in women, comprise hypothyroidism, goiter, or sometimes hyperthyroidism, through interference with the iodine symporter. The increase in thyroid volume is early. Prevalence of goiter is 4 times higher than in the general population and hypothyroidism (8-20%) more frequent in case of pre-existing thyroid autoimmunity. Hyperthyroidism likely to worsen mood is reported in 5% of cases but the causal link to lithium is unproven. An increase in serum calcium and PTH occurs in 30% of cases, as lithium stimulates parathyroid cell proliferation by activating the Wnt pathway. The risk of hyperparathyroidism, by adenoma and especially by hyperplasia, is 5 times higher than in the general population, with the particularity of frequent low urine calcium by action on the calcium-sensing receptor (CaSR). Renal complications include risk of acute or chronic renal failure and nephrogenic diabetes insipidus, which is a factor for hypernatremia and hypercalcemia through dehydration. Nephrogenic diabetes insipidus is not always reversible after lithium therapy discontinuation. Metabolically, weight gain can be observed, but rather less than with other psychotropic drugs, and lithium does not in itself induce diabetes. At pituitary level, corticotropic activation is frequent, but implicating the disease rather than lithium. Lithium treatment induces little or no hyperprolactinemia. Regular monitoring of serum calcium, the ionogram, creatinine and TSH is recommended in lithium treatment.

Dunnigan lipodystrophy syndrome: French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins)

Dunnigan syndrome, or Familial Partial Lipodystrophy type 2 (FPLD2; ORPHA 2348), is a rare autosomal dominant disorder due to pathogenic variants of the LMNA gene. The objective of the French National Diagnosis and Care Protocol (PNDS; Protocole National de Diagnostic et de Soins), is to provide health professionals with a guide to optimal management and care of patients with FPLD2, based on a critical literature review and multidisciplinary expert consensus. The PNDS, written by members of the French National Reference Center for Rare Diseases of Insulin Secretion and Insulin Sensitivity (PRISIS), is available on the French Health Authority website (in French). Dunnigan syndrome is characterized by a partial atrophy of the subcutaneous adipose tissue and by an insulin resistance syndrome, associated with a risk of metabolic, cardiovascular and muscular complications. Its prevalence, assessed at 1/100.000 in Europe, is probably considerably underestimated. Thorough clinical examination is key to diagnosis. Biochemical testing frequently shows hyperinsulinemia, abnormal glucose tolerance and hypertriglyceridemia. Elevated hepatic transaminases (hepatic steatosis) and creatine phosphokinase, and hyperandrogenism in women, are common. Molecular analysis of the LMNA gene confirms diagnosis and allows for family investigations. Regular screening and multidisciplinary monitoring of the associated complications are necessary. Diabetes frequently develops from puberty onwards. Hypertriglyceridemia may lead to acute pancreatitis. Early atherosclerosis and cardiomyopathy should be monitored. In women, polycystic ovary syndrome is common. Overall, the management of patients with Dunnigan syndrome requires the collaboration of several health care providers. The attending physician, in conjunction with the national care network, will ensure that the patient receives optimal care through regular follow-up and screening. The various elements of this PNDS are described to provide such a support.

Purity of islet preparations and 5-year metabolic outcome of allogenic islet transplantation

In allogenic islet transplantation (IT), high purity of islet preparations and low contamination by nonislet cells are generally favored. The aim of the present study was to analyze the relation between the purity of transplanted preparations and graft function during 5 years post-IT. Twenty-four patients with type 1 diabetes, followed for 5 years after IT, were enrolled. Metabolic parameters and daily insulin requirements were compared between patients who received islet preparations with a mean purity <50% (LOW purity) or ≥50% (HIGH purity). We also analyzed blood levels of carbohydrate antigen 19-9 (CA 19-9)-a biomarker of pancreatic ductal cells-and glucagon, before and after IT. At 5 years, mean hemoglobin A1c (HbA1c levels) (P = .01) and daily insulin requirements (P = .03) were lower in the LOW purity group. Insulin independence was more frequent in the LOW purity group (P < .05). CA19-9 and glucagon levels increased post-IT (P < .0001) and were inversely correlated with the degree of purity. Overall, our results suggest that nonislet cells have a beneficial effect on long-term islet graft function, possibly through ductal-to-endocrine cell differentiation. ClinicalTrial.gov NCT00446264 and NCT01123187.

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Parathormone (PTH), produced by parathyroid glands, is the main regulator of calcium homeostasis. Hypoparathyroidism (hypoPT), due to decrease of PTH production, is a rare disease. Symptoms are multiple, altering function of several organs and leading to a decrease of quality of life. Acquired etiologies, including thyroïdectomy, the main cause of hypoPT, can be distinguished from congenital etiologies, including genetic defects. HypoPT, which is classically treated by supplementation by calcium and active vitamin D, can now be treated by recombinant injection in certain indications as a poor control under classical therapy. Here are summarized current knowledge on etiologies, epidemiology, clinical manifestations and management of hypoPT.

Diseases associated with calcium-sensing receptor

The calcium-sensing receptor (CaSR) plays a pivotal role in systemic calcium metabolism by regulating parathyroid hormone secretion and urinary calcium excretion. The diseases caused by an abnormality of the CaSR are genetically determined or are more rarely acquired. The genetic diseases consist of hyper- or hypocalcemia disorders. Hypercalcaemia disorders are related to inactivating mutations of the CASR gene either heterozygous (autosomal dominant familial benign hypercalcaemia, still named hypocalciuric hypercalcaemia syndrome type 1) or homozygous (severe neonatal hyperparathyroidism). The A986S, R990G and Q1011E variants of the CASR gene are associated with higher serum calcium levels than in the general population, hypercalciuria being also associated with the R990G variant. The differential diagnosis consists in the hypocalciuric hypercalcaemia syndrome, types 2 (involving GNA11 gene) and 3 (involving AP2S1 gene); hyperparathyroidism; abnormalities of vitamin D metabolism, involving CYP24A1 and SLC34A1 genes; and reduced GFR. Hypocalcemia disorders, which are more rare, are related to heterozygous activating mutations of the CASR gene (type 1), consisting of autosomal dominant hypocalcemia disorders, sometimes with a presentation of pseudo-Bartter’s syndrome. The differential diagnosis consists of the hypercalciuric hypocalcaemia syndrome type 2, involving GNA11 gene and other hypoparathyroidism aetiologies. The acquired diseases are related to the presence of anti-CaSR antibodies, which can cause hyper- or especially hypocalcemia disorders (for instance in APECED syndromes), determined by their functionality. Finally, the role of CaSR in digestive, respiratory, cardiovascular and neoplastic diseases is gradually coming to light, providing new therapeutic possibilities. Two types of CaSR modulators are known: CaSR agonists (or activators, still named calcimimetics) and calcilytic antagonists (or inhibitors of the CasR). CaSR agonists, such as cinacalcet, are indicated in secondary and primary hyperparathyroidism. Calcilytics have no efficacy in osteoporosis, but could be useful in the treatment of hypercalciuric hypocalcaemia syndromes.

CYP24A1 Mutations in a Cohort of Hypercalcemic Patients: Evidence for a Recessive Trait

CONTEXT

Loss-of-function mutations of CYP24A1 (which encodes the 25-OH-D3-24-hydroxylase) have recently been reported to cause hypercalcemia.

OBJECTIVES

The aims of this study were: 1) to evaluate the frequency of CYP24A1 mutations in patients with medical history of hypercalcemia; 2) to show the clinical utility of a simultaneous assay of serum 25-hydroxyvitamin D3 (25-OH-D3) and 24,25-dihydroxyvitamin D3 (24,25-[OH]2D3) by liquid chromatography tandem mass spectrometry (LC-MS/MS); and 3) to investigate biochemical parameters in heterozygous gene carriers with CYP24A1 mutations.

PATIENTS AND METHODS

We screened for CYP24A1 mutations in 72 patients with serum calcium levels > 2.6 mmol/L and PTH levels < 20 pg/mL and recruited 24 relatives after genetic counseling for subsequent investigations. Vitamin D metabolite concentrations were assessed in a subset of patients by LC-MS/MS and results expressed as a ratio (R) of 25-OH-D3:24,25-(OH)2D3.

RESULTS

Twenty-five patients with hypercalcemia (35%) harbored CYP24A1 variations. Twenty (28%) had biallelic variations, mostly found in subjects with nephrocalcinosis or renal stones (19/20). Five patients, all neonates, were heterozygous, without renal disease. We describe 15 new variations leading to loss-of-function according to pathogenicity prediction programs, and we functionally characterized 5 of them in vitro. A dramatic increase of R, usually >80, was found in patients harboring biallelic mutations providing evidence in vivo for the loss of CYP24A1 activity. In contrast, R value remains <25 in patients without CYP24A1 mutations. Subjects carrying one mutant allele, hypercalcemic individuals, as well as gene-carrier relatives, had a detectable 24,25-(OH)2D3 level and R < 25, indicating normal 24-hydroxylase activity.

CONCLUSION

CYP24A1 biallelic mutations are frequently found in patients presenting with hypercalcemia, low PTH, and renal disease. We confirm the accuracy and effectiveness of a novel blood test estimating the ratio between relevant vitamin D metabolites as a useful screening tool for CYP24A1 mutations. Haploinsufficiency is not associated with CYP24A1 deficiency.

Treating diabetes with islet transplantation: lessons from the past decade in Lille

Type 1 diabetes (T1D) is due to the loss of both beta-cell insulin secretion and glucose sensing, leading to glucose variability and a lack of predictability, a daily issue for patients. Guidelines for the treatment of T1D have become stricter as results from the Diabetes Control and Complications Trial (DCCT) demonstrated the close relationship between microangiopathy and HbA1c levels. In this regard, glucometers, ambulatory continuous glucose monitoring, and subcutaneous and intraperitoneal pumps have been major developments in the management of glucose imbalance. Besides this technological approach, islet transplantation (IT) has emerged as an acceptable safe procedure with results that continue to improve. Research in the last decade of the 20th century focused on the feasibility of islet isolation and transplantation and, since 2000, the success and reproducibility of the Edmonton protocol have been proven, and the mid-term (5-year) benefit-risk ratio evaluated. Currently, a 5-year 50% rate of insulin independence can be expected, with stabilization of microangiopathy and macroangiopathy, but the possible side-effects of immunosuppressants, limited availability of islets and still limited duration of insulin independence restrict the procedure to cases of brittle diabetes in patients who are not overweight or have no associated insulin resistance. However, various prognostic factors have been identified that may extend islet graft survival and reduce the number of islet injections required; these include graft quality, autoimmunity, immunosuppressant regimen and non-specific inflammatory reactions. Finally, alternative injection sites and unlimited sources of islets are likely to make IT a routine procedure in the future.

[Management of endocrine dysfunctions after allogeneic hematopoietic stem cell transplantation: a report of the SFGM-TC on gonadal failure and fertility]

In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC) set up the third annual series of workshops which brought together practitioners from all member centers and took place in October 2012 in Lille. Here we report our results and recommendations regarding the management of short and long-term endocrine dysfunction following allogeneic stem cell transplantation. The key aim of this workshop was to give an overview gonadal failure, fertility preservation and post-transplant.

[Management of endocrine dysfunctions after allogeneic hematopoietic stem cell transplantation: a report of the SFGM-TC on adrenal insufficiency and osteoporosis]

In the attempt to harmonize clinical practices between different French transplantation centers, the French Society of Bone Marrow Transplantation and Cell Therapy (SFGM-TC) set up the third annual series of workshops which brought together practitioners from all member centers and took place in October 2012 in Lille. Here we report our results and recommendations regarding the management of short and long-term endocrine dysfunction following allogeneic stem cell transplantation. The key aim of this workshop was to give an overview on secondary adrenal insufficiency and osteoporosis post-transplant.

Islet survival and function following intramuscular autotransplantation in the minipig

The liver may not be an optimal site for islet transplantation due to obstacles by an instant blood-mediated inflammatory response (IBMIR), and low revascularization of transplanted islets. Therefore, intramuscular islet transplantation (IMIT) offers an attractive alternative, based on its simplicity, enabling easier access for noninvasive graft imaging and cell explantation. In this study, we explored the outcome of autologous IMIT in the minipig (n = 30). Using the intramuscular injection technique, we demonstrated by direct histological evidence the rapid revascularization of islets autotransplanted into the gracilius muscle. Islet survival assessment was performed using immunohistochemistry staining for insulin and glucagon up to a period of 6 months. Furthermore, we showed the crucial role of minimizing mechanical trauma to the myofibers and limiting exocrine contamination. Intramuscular islet graft function after transplantation was confirmed by documenting the acute insulin response to intravenous glucose in 5/11 pancreatectomized animals. Graft function after IMIT remained however significantly lower than the function measured in 12 out of 18 minipigs who received a similar islet volume in the liver through intraportal infusion. Collectively, these results demonstrated in a clinically relevant preclinical model, suggest IMIT as a promising alternative to intraportal infusion for the transplantation of β cells in certain medical situations.

Phenotype-genotype correlation and follow-up in adult patients with hypokalaemia of renal origin suggesting Gitelman syndrome

INTRODUCTION

Gitelman syndrome (GS) is a tubulopathy caused by SLC12A3 gene mutations, which lead to hypokalaemic alkalosis, secondary hyperaldosteronism, hypomagnesaemia and hypocalciuria.

AIM

The aim of this study was to assess the prevalence of SLC12A3 gene mutations in adult hypokalaemic patients; to compare the phenotype of homozygous, heterozygous and non-mutated patients; and to determine the efficiency of treatment.

METHODS

Clinical, biological and genetic data were recorded in 26 patients.

RESULTS

Screening for the SLC12A3 gene detected two mutations in 15 patients (six homozygous and nine compound heterozygous), one mutation in six patients and no mutation in five patients. There was no statistical difference in clinical symptoms at diagnosis between the three groups. Systolic blood pressure tended to be lower in patients with two mutations (P=0.16). Hypertension was unexpectedly detected in four patients. Five patients with two mutated alleles and two with heterozygosity had severe manifestations of GS. Significant differences were observed between the three groups in blood potassium, chloride, magnesium, supine aldosterone, 24 h urine chloride and magnesium levels and in modification of the diet in renal disease. Mean blood potassium levels increased from 2.8 ± 0.3, 3.5 ± 0.5 and 3.2 ± 0.3 before treatment to 3.2 ± 0.5, 3.7 ± 0.6 and 3.7 ± 0.3 mmol/l with treatment in groups with two (P=0.003), one and no mutated alleles respectively.

CONCLUSION

In adult patients referred for renal hypokalaemia, we confirmed the presence of mutations of the SLC12A3 gene in 80% of cases. GS was more severe in patients with two mutated alleles than in those with one or no mutated alleles. High blood pressure should not rule out the diagnosis, especially in older patients.

Diabetes cell therapy: a decade later

Type 1 diabetes is an intrinsically unstable condition because of the loss of both insulin secretion and glucose sensing. Guidelines to treat type 1 diabetes have become stricter since results from the Diabetes Control and Complications Trial (DCCT) demonstrated the close relationship between microangiopathy and HbA1c levels. Therapeutic strategies first require the treatment of underlying organic causes of the brittleness associated with the optimization of insulin therapy including continuous subcutaneous insulin infusion and glucose monitoring. Alternative approaches may still be needed for the most severely affected patients. During the last decade, islet transplantation has gone from an inconsistent 1-year rate of insulin independence of 10% to 80% and could reach 50% at 5 years, at the expense of non-negligible side effects. Among potential causes of islet transplantation success, sufficient islet mass and low levels of cellular autoimmunity are of critical importance. The main issues are currently the availability of an unlimited source of insulin-secreting cells, and the immunosuppressive drug side effects. Today, islet alone and islet after kidney transplantation are offered in a limited number of isolation centres, usually in clinical trials. Islet after kidney transplantation can be considered in type 1 diabetic patients with end-stage kidney disease that are ineligible for double kidney-pancreas transplantation. Islet transplantation alone is proposed to C-peptide negative adult diabetic patients with a body weight <80 kg or low daily insulin needs with creatinine clearance above 60 ml/min, albuminuria lower than 300mg/24H and without desire for pregnancy in women. Currently and until a more complete assessment of the 5- and probably 10-year overall benefit-risk ratio is available, islet transplantation remains a clinical research procedure.

Who should benefit from diabetes cell therapy?

Type 1 diabetes are intrinsically unstable conditions because of the loss of both insulin secretion and glucose sensing. Guidelines to treat type 1 diabetes have become stricter since the Diabetes Control and Complications Trial (DCCT) results demonstrated the close relationship between microangiopathy and HbA1c levels, whereas the deleterious role of glucose variability on macroangiopathy has been more recently suspected. Therapeutic strategies first require the treatment of underlying organic causes of the brittleness whenever possible and, secondly, the optimization of insulin therapy using analogues, multiple injections and consideration of continuous subcutaneous insulin infusion. Alternative approaches may still be needed for the most severely affected patients, including islet transplantation. We propose islet after kidney transplantation in diabetic patients with end-stage kidney disease ineligible for double kidney-pancreas transplantation (i.e C peptide negative patients over 45 years of age or with severe macroangiopathy) if creatinine blood levels are stable below 20mg/l at least six months after kidney transplantation and steroid discontinuation. Islet transplantation alone is proposed to (1) C peptide negative diabetic patients, (2) aged 18-65 with a duration of diabetes of at least five years, (3) treated with intensive subcutaneous insulin therapy, but unable to obtain a glycated hemoglobin level below 7% without hypoglycemia and / or with brittleness and unpredictable hyper- and hypoglycemia altering quality of life, (4) with normal body weight (< 80 kg) and / or low daily insulin needs (the lower, the better), (5) with renal function close to normal (creatinine clearance above 60 ml/min with albuminuria lower than 300 mg/24 h), (6) with no desire for pregnancy in women. Currently and until more complete assessment of the 5-year overall benefit-risk ratio, islet transplantation remains a clinical research procedure. As already provided for other types of transplantation, and once recognized as a "routine" procedure, prioritization of enlisted patients for islet transplantation could be aided by the calculation of a score that should be determined by a multidisciplinary team.

Does the RET variant G691S influence the features of sporadic medullary thyroid carcinoma?

OBJECTIVE

The RET (rearranged during transfection) proto-oncogene G691S variant is over-represented in the germline of patients with sporadic medullary thyroid carcinoma (sMTC) vs. normal controls but so far is not associated with any medical or pathological features of the tumour. The aim of our study was to assess the influence of this variant on the age of onset, clinical, biological and pathological features of sMTC.

DESIGN AND PATIENTS

One hundred patients with histologically proven MTC, for whom the germline genetic analysis of RET was negative and medical records were available, were included in the study.

RESULTS

Patients with the heterozygous GS variant or the homozygous SS variant (n = 36) were on average 8.0 years younger than patients with the wild-type GG variant (n = 64, mean age 43.9 vs. 51.9 years, P < 0.01). The former group did not differ from the wild-type group in terms of MTC size, prevalence of C-cell hyperplasia (CCH) or papillary thyroid carcinoma (PTC). However, the prevalence of an increased preoperative basal calcitonin (bCT) level (> 1000 pg/ml) was 2.75-fold higher in the patients with the GS or SS variant than in those with the wild-type variant (P < 0.001). The proportion of patients with lymph node metastases was also higher in the former group (P < 0.05). Multivariate analysis confirmed that the presence of the RET variant is independently associated with higher preoperative bCT values (P = 0.011).

CONCLUSIONS

Our data demonstrate that the RET G691S variant could modulate the age of onset of sMTC as demonstrated previously for familial tumours. Moreover, this variant is an independent predictor of a higher basal calcitonin synthesis rate in patients with sMTC.

Fertility and obstetrical complications in women with LMNA-related familial partial lipodystrophy

OBJECTIVE

Familial partial lipodystrophy due to LMNA (lamin A/C) mutations is a rare disorder characterized by a selective loss of adipose tissue and insulin resistance. Dyslipidemia and severe diabetes often occur during its evolution. Only isolated and contradictory case reports have been published on the obstetrical prognosis in lipodystrophy. The aim of our study was to compare the fertility and occurrence of obstetrical complications of women with familial partial lipodystrophy due to LMNA (lamin A/C) mutations with those of nonaffected relatives, women from the general population, and women with polycystic ovary syndrome (PCOS).

MATERIAL AND METHODS

Data were obtained from clinical follow-up of seven families with patients exhibiting mutations in LMNA (five R482W, one R482Q, one R439C) (14 affected among 48 women).

RESULTS

The mean number of live children per woman was 1.7 in affected patients vs. 2.8 in nonaffected relatives. Fifty-four percent of LMNA-mutated women exhibited a clinical phenotype of PCOS, 28% suffered from infertility, 50% experienced at least one miscarriage, 36% developed gestational diabetes, and 14% experienced eclampsia and fetal death. Mean blood leptin level was significantly lower in LMNA-mutated patients than in nonaffected relatives (5.0 +/- 3.8 ng/ml vs 14.3 +/- 3.6; P < 0.001) despite similar body mass index (21.0 +/- 4.2 vs 22.4 +/- 2.2; P = 0.49).

CONCLUSION

In these LMNA-linked lipodystrophic patients, the prevalence of PCOS, infertility, and gestational diabetes was higher than in the general population. Moreover, the prevalence of gestational diabetes and miscarriages was higher in lipodystrophic LMNA-mutated women than previously reported in PCOS women with similar body mass index. Women with lipodystrophies due to LMNA mutations are at high risk of infertility, gestational diabetes, and obstetrical complications and require reinforced gynecological and obstetrical care.

Acute insulin response to arginine in deceased donors predicts the outcome of human islet isolation

Despite a stringent donor selection, human islet isolation remains frustratingly unpredictable. In this study, we measured acute insulin response to arginine (AIRarg), an in vivo surrogate measure of islet mass, in 29 human deceased donors before organ donation, and correlated values with the outcome of islet isolation. Thirteen isolations (45%) met the threshold for clinical islet transplantation. Among all measured donor characteristics, the only discriminating variable between successful or unsuccessful isolations was donor AIRarg (p < 0.01). Using a threshold of 55 microIU/mL (ROC curve AUC: 72%), isolation was successful in 12/19 donors with high AIRarg and in 1/10 donors with low AIRarg (p < 0.001). The negative and positive predictive values were 90 and 63%, respectively. If used to select donors in the entire cohort, AIRarg would have increased our success rate by 40% and avoided 56% of unsuccessful isolations while missing only 8% of successful preparations. Our results suggest that donor AIRarg is markedly superior to body mass index (BMI) and other criteria currently used to predict isolation outcome. If routinely performed in deceased donors, this simple test could significantly reduce the failure rate of human islet isolation.

11β-hydroxystéroïde déshydrogénases. Avancées récentes

11beta-hydroxysteroide dehydrogenase (11beta-OHSD) enzymes exhibit a regulating action upon cortisol metabolism before access to its receptors. Two types of isoenzymes have been described, type 2 being the most anciently known. Type 2 11beta-OHSD, which changes cortisol into cortisone, is a unidirectional dehydrogenase mainly located in kidney, that protects mineralocorticoid receptors from illicit activation by glucocorticoids. Mutations of the gene coding for this enzyme has been demonstrated in apparent mineralocorticoid excess, which induces hypertension and hypokalemia with low renin and aldosterone levels. Polymorphisms of this gene could modulate essential hypertension and also be responsible for certain forms of acquired apparent mineralocorticoid excess especially after liquorice intoxication, in hypothyroidism, Cushing syndrome, and chronic renal insufficiency. Type 1 11beta-OHSD, which changes cortisone into cortisol, is a reductase, mainly located in liver and adipose tissue. Functional defects of this enzyme have been shown in polycystic ovaries and cortisone reductase deficiency. By contrast, metabolic syndrome, corticoid-induced osteoporosis, and glaucoma are linked to a local over-activity of this enzyme. The understanding of action mechanisms of these two enzymes currently leads to 11beta-OHSD inhibitors development, therefore opening new therapeutic strategies, especially in metabolic syndrome.

Contribution of genetic analysis in screening for MEN1 among patients with sporadic disease and one or more typical manifestation

Multiple Endocrine Neoplasia type 1 (MEN1) is an autosomal dominant hereditary syndrome (OMIM 131100) due to MEN1 gene mutations, predisposing to the development of hyperplasic and tumoral lesions of neuroendocrine tissues. Since the identification of the gene in 1997, more than 400 different mutations of MEN1 have been registered. Genotypic analysis of MEN1 remains fastidious and must be reserved to targeted situations. If the lesions appear in a familial assessed context, there is a strong argument to search for MEN1 mutation. This is not the case in a sporadic context. With experience acquired in our laboratory, we evaluated the frequency of MEN1 mutations in patients with sporadic presentations. Our aim was to better define criteria for MEN1 genotypic analysis. One hundred and twenty four blood samples from unrelated patients, who gave their written informed consent, were analyzed. These patients exhibited 1 to 4 manifestations of MEN1 without any familial context. After DNA extraction, the analysis was undertaken by PCR-sequencing of all the MEN1 coding exons and exon/intron boundaries or by PCR of the pre-screened fragments alone, a technique made possible by indirect screening mutation methods. Mutations were identified by comparing the sequences to the reference MEN1 sequence available from GENBANK (U93237.1). Mutations were identified in 19 patients, with variable prevalence according to clinical manifestations: 100% for patients with 4 manifestations, 45.5% for patients with 3 manifestations, 19% for patients with 2 manifestations and 2% for patients with only one manifestation. Mutations were: 11 point variations (58%), including 2 splicing sites and 8 frameshift mutations (42%) including 5 deletions, 2 insertions and 1 insertion/deletion; one mutation was identified twice. We showed a relationship between clinical presentation and MEN1 mutation identification, especially with the number of clinical manifestations but also with the type of manifestation. Pancreatic manifestations were significantly linked with probability of mutation. In a sporadic context with at least two established manifestations of MEN1, the overall probability of identifying a mutation was 26%, warranting MEN1 genotypic analysis.

Familial partial lipodystrophy due to the LMNA R482W mutation with multinodular goitre, extrapyramidal syndrome and primary hyperaldosteronism

Objective To describe new data about the wide phenotypic variability of diseases due to mutations in the lamin A/C gene (LMNA). Design We report a complex phenotype in a patient with familial partial lipodystrophy of the Dunnigan type (FPLD) and study the frequency of her unusual clinical signs in 19 other LMNA-mutated lipodystrophic patients from 8 different families and 14 non-mutated family members. Case Report The patient was diagnosed with FPLD due to the R482W LMNA mutation after familial screening. Surprisingly, she had no biological signs of insulin resistance. The presence of hypertension with hypokalaemia led to the diagnosis of primary hyperaldosteronism. Thyroid investigations showed a euthyroid multinodular goiter. In addition, the patient exhibited a juvenile akineto-hypertonic syndrome. Results Goiter was identified with a similar frequency (55%) in LMNA-mutated lipodystrophic patients (11 out of 20, originating from 5 families among 8) compared to non-mutated family controls (35%; 5 patients out of 14, all originating from the same family). No case of primary hyperaldosteronism or extrapyramidal syndrome was identified in other studied subjects, either LMNA-mutated or not. Conclusions This R482W-LMNA mutated patient showed an association of features (primary hyperaldosteronism, euthyroid goiter and extra-pyramidal syndrome, raising the question of a link with her laminopathy. Prevalence of goiter tended to be higher in LMNA-mutated than in non-mutated subjects. Hyperaldosteronism seems coincidental. Although extrapyramidal syndrome has never been reported in lipodystrophic patients, it may nevertheless be linked to the LMNA mutation since multiple neurological features have been associated with alterations in lamins A/C.

Calcitonin levels do not decrease with weaning in chronic alcoholism

OBJECTIVE

Alcohol might increase calcitonin but this assertion is mainly based on the acute effect of the drug in small animals and humans. The aim of this study was to investigate the effect of chronic alcoholic intoxication on plasma calcitonin (CT) levels.

DESIGN

20 smoking male subjects admitted to be weaned from chronic daily alcohol consumption >100 g were included after informed consent. Blood was sampled upon admission (T0) and after 5 (T5) and 21 (T21) days of alcohol weaning to measure mean erythrocyte volume, gamma-glutamyltransferase (GGT), calcium, gastrin, and CT levels. The control group consisted of 30 male subjects with daily alcohol consumption <20 g.

MAIN OUTCOME

The characteristics of the alcohol group were as follows (mean +/- SD): age 41.2 +/- 13 years old; mean erythrocyte volume: 96.0 +/- 4.2 microm(3) (N: 85-95); calcium level: 94.7 +/- 3.7 mg/L (N: 85-105); gastrinemia: 59.3 +/- 14.9 ng/mL (N: <120). At T0 and T21, three alcoholic subjects had CT levels above 10 pg/mL, usually considered as the normal cut-off value. There was no correlation between CT and the different biochemical parameters at T0, T5, and T21. There was no difference between CT levels at the different stages in the alcohol group (T0: 6.4 +/- 3.6 pg/mL; T5: 6.5 +/- 5.3 pg/mL; T21: 8.4 +/- 5.6), although GGT significantly decreased with weaning duration (T0: 248 +/- 354 IU/L; T5: 211 +/- 290 IU/L; T21: 79 +/- 90 IU/L; ANOVA, p <0.05). But a significant difference was found between mean CT levels in the alcohol group and in the control group (3.1 +/- 0.7 pg/mL, p <0.0001).

CONCLUSIONS

This study suggests that mean CT levels of chronically alcoholic smoking male subjects are higher than those of an age- and sex-matched control group. However, most alcoholic patients exhibited CT levels <10 pg/mL. No decrease in CT levels was noted over a short period of alcohol weaning. As CT measurement is currently recommended in thyroid nodule assessment, this finding may be important to know how to decipher borderline values of CT.

Effects of non-steroid immunosuppressive drugs on insulin secretion in transplantation

Post-transplantation diabetes (PTD) is a serious complication in organ transplantation: not only does it increase the risk of graft dysfunction; it also increases cardiovascular morbidity and mortality. PTD incidence is correlated with age, non-Caucasian ethnic background, a family history of diabetes, excess weight, hepatitis C infection and steroid boluses for potential rejection. Different mechanisms might explain post-transplantation glucose metabolism disorders: ischemia-reperfusion disorders, whether renal, hepatic or cardiac, are responsible for insulin-resistance, which is increased by post-transplantation steroids; the detrimental effect of non-steroid immunosuppressive drugs on insulin-secretion could also be involved, especially with calcineurin inhibitors. In vivo and in vitro studies have shown that tacrolimus has inhibitory effects on insulin-secretion, while these effects are less obvious for cyclosporin, and were mainly demonstrated in vitro. Mycophenolate has no overt effect on insulin-secretion. Sirolimus and everolimus, two mTOR inhibitors, have shown controversial results in this realm. The effects of sirolimus (most often studied mTOR inhibitor) appear to depend on serum levels, cell type (ss cell or cell line), species (human or animal) and also environmental nutrients. At therapeutic concentrations, a stimulatory effect on insulin secretion was observed on human beta cells. This might explain the success of islet cell transplantation with the Edmonton protocol. Finally, steroids are mainly detrimental because they accentuate insulin resistance whereas anticalcineurins, in particular tacrolimus, lower insulin synthesis.

Management strategies for brittle diabetes

Type 1 diabetes is an intrinsically unstable condition. However, the term "brittle diabetes" is reserved for those cases in which the instability, whatever its cause, results in disruption of life and often recurrent and/or prolonged hospitalization. It affects 3/1000 insulin-dependent diabetic patients, mainly young women. Its prognosis is poor with lower quality of life scores, more microvascular and pregnancy complications and shortened life expectancy. Three forms have been described: recurrent diabetic ketoacidosis, predominant hypoglycemic forms and mixed instability. Main causes of brittleness include malabsorption, certain drugs (alcohol, antipsychotics), defective insulin absorption or degradation, defect of hyperglycemic hormones especially glucocorticoid and glucagon, and above all delayed gastric emptying as a result of autonomic neuropathy. Psychosocial factors are very important and factitious brittleness may lead to a self-perpetuating condition. The assessment of brittle diabetes requires quantification of the variability of blood glucose levels. To quantify instability, measures which have been developed, include Mean Amplitude of the largest Glycemic Excursions (MAGE), Mean Of Daily Differences (MODD), Lability Index (LI), Low Blood Glucose Index (LBGI), Clarke's score, Hyposcore, and continuous blood glucose monitoring. Once psychogenic problems have been excluded, therapeutic strategies require firstly, the treatment of underlying organic causes of the brittleness whenever possible and secondly optimising standard insulin therapy using analogues, multiple injections and consideration of Continuous Subcutaneous Insulin Infusion. Alternative approaches may still be needed for the most severely affected patients. Isolated islet transplantation (IIT), which restores glucose sensing, should be considered in cases of hypoglycaemic unawareness and/or lability especially if the body mass index is < 25, but with current immunosuppressive protocols patients must have normal renal function and preferably no plans for pregnancy. Implantable pumps have advantages for patients who either weigh more than 80 kgs or have abnormalities of kidney or liver function or are highly sensitised.

Acute insulin response (AIR): review of protocols and clinical interest in islet transplantation

Various stimuli have been used in clinical practice to test islet function, including intravenous glucose, arginine--both at basal glucose levels and with the hyperglycaemic clamp, tolbutamide, glucagon and glucagon-like peptide 1. The subsequent first phase insulin response (also termed acute insulin response or AIR) to intravenous glucose or arginine has been quantified in a variety of ways, from the mean serum insulin measured at multiple times after glucose injection to the mean value above baseline of serum insulin at 2 to 10 min. The purpose of this study was to review the different protocols of AIR calculation and their pitfalls, and to assess the results of AIR in the islet transplantation field. By investigating the first phase of insulin secretion, AIR provides both a qualitative and a quantitative approach to insulin secretion. In islet transplantation, post-glucose AIR (AIRg) may predict graft survival while post-arginine AIR (AIRa) may be better correlated with engrafted beta cell mass, despite these facts need to be confirmed. AIRa also limits intravenous hyperglycaemia glucotoxicity. In conclusion, AIR could help to predict the need for a second or third islet injection in islet transplantation. These specific indications, however, need to be confirmed by future studies and completed by other approaches such as insulin sensitivity studies and in vivo morphological assessment of islet mass.

Le récepteur sensible au calcium : physiologie et pathologie

Calcium is a major ion in human metabolism and its level is highly controlled. This regulation is performed via the Calcium Sensing Receptor, a discovery which ten years ago led to the explanation of a number of clinical disorders. The syndromes caused by CaSR abnormalities are characterized by hypercalcemia or hypocalcemia, associated with inappropriate calciuria. An underlying genetic or auto-immune cause may be demonstrated. High blood calcium levels linked to mutations of the CaSR gene lead to familial hypocalciuric hypercalcemia and the neonatal and non neonatal forms with severe hypercalcemic. Hypocalcemia determined by mutations in the CaSR gene include autosomal dominant hypocalcemia and its sporadic form. Another clinical presentation similar to Bartter syndrome has been reported. Auto-antibodies directed against CaSRs, seen in auto-immune diseases, can lead to similar clinical presentations. Finally, CaSR polymorphisms modulate the range of blood calcium levels. With diagnosis of these diseases deleterious therapeutics can be avoided. The discovery of this receptor has led to new therapeutic prospects such as calcimimetics for hyperthyroidism.

[Iron overload and insulin resistance]

There is increasing evidence that moderately elevated body iron stores, below levels commonly found in genetic hemochromatosis, may be associated with adverse health outcomes. Genetic hemochromatosis, characterized by transferrin saturation (TS) greater than 45%, is most often linked to homozygosity of the HFE C282Y allele. The phenotype is also modulated by mutations of more recently discovered genes (including ferroportin, hemojuvelin, hepcidin, and transferrin receptor) and environmental factors (including alcohol, viruses, diet, blood loss). Iron overload without hemochromatosis is characterized by high levels of serum ferritin and normal TS, as seen in dysmetabolic hepatosiderosis. Elevated serum ferritin levels predict incident type 2 diabetes in prospective studies and have been associated with hypertension, dyslipidemia, glucose tolerance disturbances, central adiposity, and metabolic syndrome. High ferritin levels are not synonymous with iron overload and may in some cases be a simple marker of insulin resistance.

Hypophosphatémies génétiquement déterminées chez l’adulte

Hereditary hypophosphatemic rickets groups together X-linked hypophosphatemic rickets (XLH), autosomal dominant hypophosphatemic rickets (ADHR) and hereditary hypophosphatemic rickets with hypercalciuria (HHRH, autosomal recessive). Clinical and biological characteristics and treatment depend on specific etiology. Mutations causing hereditary hypophosphatemic rickets involve PHEX located on Xp11.22 for XLH and FGF-23 located on 12p13 for ADHR. The gene involved in HHRH remains unknown: candidates may encode proteins that modulate phosphate transporter expression or activity. Others forms of rickets must be ruled out: acquired hypophosphatemia due to oncogenic osteomalacia, X-linked recessive hypophosphatemic rickets or Dent's disease, and hereditary 1, 25-dihydroxyvitamin D-resistant rickets with a defect either in the 1-alpha-hydroxylase gene (pseudo-vitamin D deficiency rickets, PDDR) or in the vitamin D receptor (hereditary vitamin D-resistant rickets, HVDRR).

Les hypercalciuries

The frequency of hypercalciuria is increasing in western countries with an incidence of nephrolithiasis which can reach 13%. Hypercalciuria appears as an alteration of the calcium transport system (kidney, bowel, bone) which is regulated by calcitriol and parathormone. The aim of this review was to screen etiologies of hypercalciuria taking into account recent genetic advances (calcium epithelial channel and calcium sensing receptor). Hypercalciuria may be favored by nutritional causes (diet rich in calcium, sodium, carbohydrates, proteins, poor in phosphates and potassium). It may also be related to an increase in calcium absorption (vitamin D excess, primary hyperparathyroidism, sarcoidosis, lymphoma, estrogens, and certain genetic causes), an increase in osteoresorption (bone metastasis, myeloma, Paget, hyperthyroidism, immobilization, hypercortisolism and corticosteroid therapy), or a decrease of kidney tubular resorption (diuretics, Cacci and Ricci, acromegally, Bartter, familial dominant hypocalcemia, Fanconi, Dent, familial hypomagnesemia-hypercalciuria syndrome, type 1 distal tubular acidosis, pseudohypoaldosteronism, diabetes). If no cause is identified, persistence of hypercalciuria after instituting a correct diet is defined as idiopathic hypercalciuria. Treatment of the cause is essential in secondary hypercalciuria, in addition to diet (low sodium intake, normocalcic diet, hydration), associated with thiazide diuretics and biphosphonates if necessary.

Syndromes d'insulinorésistance extrême génétiquement déterminés

PURPOSE

To make a point about monogenic insulin resistance syndromes.

CURRENT KNOWLEDGE AND KEY POINTS

Extreme insulin resistance syndromes are rare entities. The clinical and biological presentation is similar to that one of metabolic syndrome. Polycystic ovaries syndrome, non-alcoholic liver steatosis, acanthosis nigricans and overall, lipo-atrophic syndrome must be sought. Genetically determined forms are mainly linked to mutations of the insulin receptor gene and to lipoatrophic syndrome-linked mutations. The three syndromes related to mutations of the insulin receptor gene are Type A syndrome, first described by Kahn in young women, whereas leprechaunism and Rabson-Mendenhall syndromes are of neonatal onset. Main insulin resistance syndromes associated with lipo-atrophy are 1) Berardinelli-Seip or congenital generalized lipo-atrophic syndrome linked to mutations of seipin or AGPAT2 gene, 2) Dunnigan or partial familial lipoatrophic syndrome linked to mutations of lamin A/C, or sometimes PPAR gamma gene, and 3) acro-mandibular dysplasia and Köbberling syndrome.

FUTURE PROSPECTS AND PROJECTS

In conclusion, an early onset of insulin resistance, especially in association with lipodystrophy must suggest a monogenic insulin resistance syndrome. Outstanding advances in insulin resistance pheno- and genotype identification, despite incomplete yet, offers a better understanding of insulin resistance, atherosclerosis and ageing mechanisms, that should lead to therapeutic improvement.

Subcutaneous insulin resistance successfully circumvented on long term by peritoneal insulin delivery from an implantable pump in four diabetic patients

Extreme subcutaneous insulin resistance is a rare syndrome characterized by a severe resistance to subcutaneous (S/C) insulin together with persistence of normal or near normal intravenous (IV) insulin sensitivity. Its pathophysiology is unknown, although increased insulin degrading activity has been reported in the S/C adipose tissue fraction in some cases. Until now, proposed treatments have been disappointing. We report 4 cases who were successfully treated by intraperitoneal (IP) route.

METHODS

The diagnosis of subcutaneous insulin resistance was based upon following combined conditions: resistance to hypoglycaemic action of subcutaneous insulin but normal or near normal sensitivity to IV or IP insulin.

RESULTS

4 patients among those followed by EVADIAC group met these criteria: 3 with type 1 diabetes (C peptide=0), the last one with unexplained non insulin-deficient diabetes (no anti-GAD antibodies, C peptide=5 ng/ml). All of them had been treated with subcutaneous insulin therapy without success despite huge doses (up to 4000 IU/day in two patients). The 3 type 1 diabetic patients presented with a history of repeated ketoacidosis episodes. A treatment of insulin mixed with aprotinin had been proposed to 2 patients without success. The IV insulin sensitivity was proved to be normal in two patients by euglycaemic clamp data. A skin biopsy was performed in 1 patient. An accumulation of insulin in the derma was revealed with no increase of degradation products of insulin. In these 4 patients, a dramatic improvement of diabetes control was obtained by IP insulin delivery from an implantable pump (HbA1c decrease by at least 3%).

CONCLUSION

Although pathophysiology of the subcutaneous insulin resistance syndrome remains unexplained, our data show that intra-peritoneal insulin therapy from an implantable pump allows diabetes control in patients affected by this uncommon but severely disabling condition.

Acute insulin response of donors is correlated with pancreatic islet isolation outcome in the pig

AIMS/HYPOTHESIS

Unpredictability of islet isolation outcome remains a frustrating and costly issue in the clinical implementation of islet transplantation. The aim of this experimental study was to test the hypothesis that the donor's insulin secretory reserve, an in vivo surrogate of functional pancreatic mass, is correlated with the outcome of islet isolation.

METHODS

Insulin secretory reserve was evaluated in 28 healthy adult minipigs prior to pancreatectomy and islet isolation. Blood glucose and insulinaemia were measured before and 1, 3, 5, 10, 15, 30, 60 and 90 min after glucose infusion. Following total pancreatectomy, islet isolation was performed according to Ricordi's semi-automated method, and the total number of islets obtained was determined. Fasting blood glucose, insulinaemia, acute insulin response (AIR), maximal insulinaemia and the glucose decay constant (K(G)) were calculated, and possible associations with the outcome of islet isolation were assessed.

RESULTS

AIR and maximal insulinaemia after glucose injection were correlated with the outcome of islet isolation (p<0.01). Mean values for AIR and maximal insulinaemia were significantly different between animals in which islet isolation was successful (n=11) vs those in which it was unsuccessful (n=17) (77.6+/-13.7 microU/ml vs 42.3+/-7.8 microU/ml, p<0.05; 144.7+/-21.6 microU/ml vs 71.9+/-10.4 microU/ml, p<0.05, respectively).

CONCLUSIONS/INTERPRETATION

This study suggests that the donor's pancreatic endocrine mass, as estimated by AIR, is a major determinant of the outcome of islet isolation in large mammals. Our results may explain the frustrating variability of human islet isolation outcome and could lead to a new approach for optimising the selection of brain-dead and/or living pancreas donors.

Le diabète de la mucoviscidose chez l’adulte

Cystic fibrosis is an autosomal recessive disorder affecting about 1/3500 case in France. The disease, that affects all epithelia, is responsible for pulmonary tract infections but also pancreas, gut, liver and genital tract abnormalities. It is linked to CFTR gene mutations, inducing unusually high increase of sodium chloride in sweat, used to track down the illness. deltaF508 CFTR mutation, encountered in 70% of cases, is nearly always associated to pancreatic insufficiency with early-onset lung attack. Around 10% of cystic fibrosis cases, whatever the age, are complicated with partially insulinopenic diabetes, favored by pancreatic fibrosis, while one third of patients shows glucose intolerance. After 20 years old, one third of patients suffers from diabetes and one half after 30 years. Diabetes diagnosis is difficult, and requires the fulfillment of oral glucose tolerance test (OGTT). One glycemia greater or equal to 2 g/l, two hours after a 75 g glucose load, established diabetes diagnosis. Indeed, fasting blood glucose and glycated hemoglobin appear as poor diagnosis markers. Despite histological arguments in favor of the mainly mechanical islet disturbances, an increased prevalence of anti-islets auto-antibodies and an increased frequency of HLA DR3/DR4 have been reported in cystic fibrosis population with glucose tolerance troubles. Also, glucose metabolism is influenced by specific factors linked to cystic fibrosis (infection, malnutrition, steroids...). In reason of the silent phase of diabetes, systematic tracking down of diabetes with a yearly OGTT is recommended, all the more so that hyperglycemia appears as a worsening factor of cystic fibrosis. The efficacy of oral anti-diabetic drugs has not been evaluated on large studies. By contrast, some studies argue for insulin therapy as soon as diabetes appears, insulin improving respiratory and nutritional prognosis. In conclusion, the aim of treatment of cystic fibrosis is to prevent the lung function decline by controlling inflammation and infection, to implement endo- and exo-crine pancreas insufficiency, and to improve nutritional status.

Technique du prélèvement pancréatique pour l'isolement des îlots de Langerhans

AIM OF THE STUDY

The allograft of pancreatic islets represents a potential alternative to insulin therapy in patients suffering from the most severe forms of Type 1 diabetes. Here we report our experience of pancreatic procurement for isolation and islet allograft.

MATERIALS AND METHODS

Pancreata were procured in brain-dead donors. The islets were isolated using techniques developed and validated in pigs and men. Injection of a given preparation was decided after quantitative and qualitative controls. Islets were transplanted in Type 1 diabetic patients already grafted with a kidney or suffering from severe and/or unstable diabetes, after percutaneous or surgical settlement of an intra-portal catheter. Patients received an "Edmonton-like" immunosuppressive protocol. Grafts were repeated once or twice until a total quantity of 10,000 transplanted islet-equivalents was obtained.

RESULTS

Twenty-nine pancreata were procured and 14 preparations were grafted to 7 patients. Eleven graftings were done percutaneously and three were surgical. The initial function of the 14 transplants was confirmed by secretion of C-peptide and decrease of insulin doses. Insulin therapy was completely interrupted in the 5 patients having received at least two grafts.

CONCLUSION

These preliminary clinical results confirmed that the isolation technique of human islets and the technique of pancreas procurement are mastered by our team. If the results of this assay (assessment one year after graft) confirm our hopes, we will be able to offer islet allografts to an increasing number of patients with severe Type 1 diabetes.

[Severe Graves' acropachy and dermopathy. Three case reports]

INTRODUCTION

Traditionally described, severe Graves' acropachy and tibial myxoedema are now only encountered in certain severe forms of Graves' disease, where they can be difficult to diagnose and hence delay the initiation of treatment.

OBSERVATIONS

Three patients presented with severe ophthalmopathy, pretibial myxoedema and acropachy of different clinical forms.

DISCUSSION

In supplement to the usual biopsies and X-rays, bone scintigraphy provides early diagnosis of acropachy. The severity of the immune disease, the episodes of hypothyroidism and cigarette smoking are the 3 main factors contributing to these extra-thyroid manifestations of Graves' disease. There is currently no treatment that can permanently resolve the functional and aesthetic problems of dermopathy and acropachy.

Selection of diabetic patients for islet transplantation. A single-center experience

OBJECTIVE

Since the Edmonton protocol, islet transplantation (IT) offers the prospect of adequate glycemic control with no major surgical risk. In our single-center experience of IT, we studied the recruitment of eligible diabetic patients.

METHODS

Between 1998 and 2002, we screened 79 diabetic patients that were divided into 2 groups according to their renal status: 41 were not receiving dialysis (ND) while 38 were receiving ongoing dialysis (D).

RESULTS

In the ND group, 20 patients initiated the contact with our team, 8 patients were recruited during hospitalization for very poor glycemic imbalance, and 13 were referred by their diabetologist. 14/41 (34%) patients were ineligible for IT either because of very good glycemic balance, detectable C-peptide (C-p), kidney or liver problems, or plans for future pregnancy. 16/41 (39%) did not wish to proceed, 7 of whom were more interested by a pump. 11/41 (27%) were eligible, among which 8 are currently being assessed, 1 is on the waiting list and 2 have been transplanted. In the D group, 17/38 (45%) had a detectable C-p and received a kidney graft alone. Among the remaining 21 C-p negative diabetic patients, 3 were not eligible for kidney transplantation mainly for psychological reasons, and 4 were enlisted for kidney+pancreas transplantation. The remaining 14 C-p negative patients were kidney-transplanted. Among them, 6 were not eligible for IT, mainly for lack of motivation, slightly positive C-p stimulation tests, obesity, cancer, or increased creatininemia. The remaining 8/14 C-p negative kidney-engrafted patients were enlisted for IT. 3 had secondary failure with the pre-Edmonton immunosuppressive (IS) protocol. Five have been transplanted with the Edmonton-like IS regimen.

CONCLUSION

Twenty-five per cent of the 79 patients for whom islet transplantation was considered underwent pregraft assessment and 12% (10 patients, 8 kidney-transplanted and 2 islet alone) of the 79 have been transplanted. The main eligibility criteria were undetectable Cpeptide, normal kidney function, average weight, glycemic imbalance, hypoglycemia unawareness, and glycemic brittleness.

Patients with familial partial lipodystrophy of the Dunnigan type due to a LMNA R482W mutation show muscular and cardiac abnormalities

Diseases due to mutations in the lamin A/C gene (LMNA) are highly heterogeneous, including neuromuscular and cardiac dystrophies, lipodystrophies, and premature ageing syndromes. In this study we characterized the neuromuscular and cardiac phenotypes of patients bearing the heterozygous LMNA R482W mutation, which is the most frequent genotype associated with the familial partial lipodystrophy of the Dunnigan type (FPLD). Fourteen patients from two unrelated families, including 10 affected subjects, were studied. The two probands had been referred for lipoatrophy and/or diabetes. Lipodystrophy, exclusively observed in LMNA-mutated patients, was of variable severity and limited to postpubertal subjects. Lipodystrophy and metabolic disturbances were more severe in women, even if an enlarged neck was a constant finding. The severity of hypertriglyceridemia and hirsutism in females was related to that of insulin resistance. Clinical muscular alterations were only present in LMNA-mutated patients. Clinical and histological examination showed an invalidating, progressive limb-girdle muscular dystrophy in a 42-yr-old woman that had been present since childhood, associated with a typical postpubertal FPLD phenotype. Six of eight adults presented the association of calf hypertrophy, perihumeral muscular atrophy, and a rolling gait due to proximal lower limb weakness. Muscular histology was compatible with muscular dystrophy in one of them and/or showed a nonspecific excess of lipid droplets (in three cases). Immunostaining of lamin A/C was normal in the six muscular biopsies. Surprisingly, calpain 3 expression was undetectable in the patient with the severe limb-girdle muscular dystrophy, although the gene did not reveal any molecular alterations. At the cardiac level, cardiac septal hypertrophy and atherosclerosis were frequent in FPLD patients. In addition, a 24-yr-old FPLD patient had a symptomatic second degree atrioventricular block. In conclusion, we showed that most lipodystrophic patients affected by the FPLD-linked LMNA R482W mutation show muscular and cardiac abnormalities. The occurrence and severity of the myopathic and lipoatrophic phenotypes varied and were not related. The muscular phenotype was evocative of limb girdle muscular dystrophy. Cardiac hypertrophy and advanced atherosclerosis were frequent. FPLD patients should receive careful neuromuscular and cardiac examination whatever the underlying LMNA mutation.

Thyroid carcinomas involving follicular and parafollicular C cells: seventeen cases with characterization of RET oncogenic activation

Recent studies have focused on the occurrence of concomitant medullary-papillary thyroid carcinomas (MTC-PTC). The aims of this report were to compare the frequency of occult PTC in a population with MTC versus a control population that had undergone thyroidectomies and to check whether differences could be related to particular phenotype or genotype. To achieve these goals, we determined the frequency of occult PTC among patients operated for MTC (n = 82) or undergoing total thyroidectomy mainly for goiter and/or nodules (n = 7313) between 1994-2001. We then examined the clinical, histologic, and genetic characteristics (using a bio-chemical family inquiry and screening for RET germline mutations) of patients with associated PTC-MTC. Results show a significantly higher frequency of occult PTC in MTC (14.7%) than in total thyroidectomy (6.8%; p < 0.01). Seventeen cases of MTC or bilateral C-cell hyperplasia (CCH) and separate occult PTC were identified from 16 different families. Although common RET mutations providing evidence of familial forms of MTC were identified in only 3 of 16 families, clinical and histologic features usually seen in inherited forms of MTC such as young age of occurrence, bilateral CCH or associated case in family were found in 11 of the remaining 14 patients. In conclusion, results suggest that the association of MTC-PTC is not only a coincidence. Surprisingly, 11 of 17 MTC-PTC patients exhibited clinical, histologic, and/or family features usually encountered in familial forms despite the fact that no RET defect were present. This suggests the possible involvement of another gene or uncommon abnormality of RET gene.

Physiopathologie de l’insulinorésistance

AMONG THE BIOLOGICAL MEDIATORS OF INSULIN RESISTANCE: two compounds released by the adipocyte are found, such as free fatty acids and tumor necrosis factor-alpha. They are incriminated in the deleterious role of visceral adiposity on the metabolic parameters. INTRA-CELL CORTISOL: Attention is also focused on the potential implication of cortisol in the genesis of metabolic syndrome, because cortisol is a potent antagonist of the effect of insulin and its presence in excess enhances visceral obesity and insulin resistance. GENETIC ASPECTS: Although no major locus has yet been identified, recent findings of several mutations or polymorphisms in genes acting in different regulation systems (adiponectin, PPARgamma2) also provide an interesting insight into the pathogenesis of this syndrome. Moreover, there is growing epidemiological evidence that intra-uterine factors could induce a so-called programming of the individual that may, at least in part, account for the difficulties encountered by the classical genetic approach.

Données épidémiologiques et critères de dépistage du syndrome métabolique

THREE DEFINITIONS: The metabolic or X syndrome is defined by an association of metabolic anomalies leading to an increased risk of cardiovascular complications. Today, there are at least 3 definitions of X syndrome: those of WHO, EGIR and NCEP. To varying degrees they associate increased abdominal fat, hypertension, glucose tolerance abnormality (ranging from hyperinsulinism to diabetes), and hypertriglyceridemia with low HDL cholesterol. FROM AN EPIDEMIOLOGICAL POINT OF VIEW: The prevalence of metabolic syndrome depends on the definition used and varies with the country or ethnic group considered. About 25% of the US and 10% of the French adult populations are concerned. THE RISK OF COMPLICATIONS: According to clinical trials, people with metabolic syndrome have a 2 to 4-fold increase in risk for coronary heart disease. Some of them have a particularly high risk (association of most features of the syndrome, association of an increased waist circumference and hypertriglyceridemia, presence of biological markers such as elevated C-reactive protein or microalbuminuria). Metabolic syndrome is also associated with a 4-fold increase in risk for developing diabetes.

Principes thérapeutiques du syndrome métabolique

GENERAL PRINCIPLES: The general progression throughout the world in type 2 diabetes has lead medical Authorities to develop mass screening but also prevention measures, notably for "high-risk" subjects such as those exhibiting a metabolic syndrome. Studies on the topic have shown that preventing type 2 diabetes was possible via lifestyle changes, possibly in association with pharmacological therapy (metformine, acarbose, thiazolidinediones, orlistat). The other therapeutic stakes in the context of the metabolic syndrome also concern the management of all identified cardiovascular risk factors. REGARDING HYPERTENSION: there are currently no specific recommendations available in the framework of metabolic syndrome, with regard to lowering blood pressure and how to obtain it. However there is evidence that patients may benefit from the strict control of blood pressure (< or =130/85 mm Hg). REGARDING DYSLIPIDEMIA: LDL cholesterol remains the main target, with a goal depending on individual cardiovascular risk (<1 or 1.30 g/l in the case of metabolic syndrome). Statins are of major interest in this context. However, it is also established that normalisation of triglycerides and HDL cholesterol contributes to the improvement of cardiovascular Issues. The respective indications for fibrates or fibrate/statin associations still need to be defined in primary as in secondary prevention.

Eligibility of diabetic patients receiving dialysis for islet after kidney transplantation

INTRODUCTION

The aim of this study was to assess the selection of candidates among 38 dialyzed diabetic patients referred between January 1, 1998 and December 31 2002 for kidney followed by islet transplantation (IAK). The main criteria of eligibility for possible IAK were as follows: (1) plasma C-peptide negative; (2) need for a kidney graft; (3) kidney plus whole pancreas transplantation not desired by the patient; and (4) acceptable results of postkidney graft preislet transplantation evaluation.

RESULTS

Seventeen of 38 patients with positive C-p diabetes received a kidney graft alone. Among the 21 C-p-negative diabetic patients, 3 were not eligible for kidney transplantation mainly for psychological reasons and 4 were eligible for kidney plus pancreas transplantation. The remaining 14 C-p-negative patients underwent kidney transplantation or had previously undergone kidney transplantation. Among them, 1 had moved away, 1 refused IAK, one had slightly positive stimulation tests, 1 was overweight, 1 had breast cancer, and 1 had postkidney graft complications. Among the remaining 8 of 14 C-p-negative, kidney-engrafted patients listed for IAK, 5 have undergone transplantation, 3 with a pre-Edmonton and 2 with the Edmonton protocol.

CONCLUSION

In conclusion among this series of 38 diabetic patients undergoing dialysis, more than 90% were kidney-grafted. Approximately 50% were ineligible for pancreas transplantation or IAK because of a positive C-p, and 20% were enlisted for IAK. These results highlight the importance of C-p determinations in diabetic dialysis patients to identify eligible patients for pancreas transplantation or IAK.

Eligibility of diabetic patients for islet transplantation alone

Since the Edmonton protocol, islet transplantation alone (ITA) offers the prospect of adequate glycemic control in type 1 diabetes without kidney failure. Patient motivation, evolution of diabetic complications, and hypoglycemia unawareness have to be balanced against the risks of portal puncture and long-term immunosuppressive therapy. The aim of this work was to assess the profile of 41 type 1 diabetic patients (21 men and 20 women of age 18 to 63 years) for whom islet transplantation was considered, between January 2000 and December 2002. Thirty-one of these patients lived in the area. The patients were divided into 3 groups according to their recruitment: 20, personal initiative (G1); 8, recruited from hospitalization (G2) for marked glycemic imbalance; and 13, (G3) referred by their diabetologist. Among this series of 41 patients, 14 (8 in G1, 4 in G2, and 2 in G3) did not fit the eligibility criteria, mainly because of a positive C-peptide, kidney failure, desire for pregnancy (G1, G3), liver disorders related to alcohol or iron overload related to HFE heterozygosity (G2), or good glycemic balance (G3). Sixteen did not wish to proceed after the first information step, 6 of these being more interested in a pump. Eleven, mainly recruited in G1 or G3, went through the clinical pretransplantation assessment. Among these, 2 have undergone transplantation, another 1 is enlisted. Therefore, it appears that patient motivation and information to the diabetologists are two important issues in the recruitment of patients eligible for islet transplantation. Equally important is the measurement of C-peptide, plasma creatinine, and microalbuminuria.

Kinetics of diabetes-associated autoantibodies after sequential intraportal islet allograft associated with kidney transplantation in type 1 diabetes

OBJECTIVE

Presence or occurrence of pancreas auto-antibodies (aAb) has been shown to be of poor prognosis for islet cell transplantation. The aim of the study was to monitor the kinetics of these aAb after sequential intra-portal islet plus kidney transplantation with pre-Edmonton immunosuppressive regimen in order to determine whether the sequential protocol of transplantation was involved in the occurrence of the immune response.

PATIENTS AND METHODS

Three patients with IDDM and a previous (IAK) or simultaneous (SIK) kidney transplantation received 3 or 4 ABO compatible islet preparations. Islets (> 8 000 IEQ/kg post culture) were sequentially transplanted within a 12 day period via a per-cutaneous catheter. Immunosuppressive treatment included cyclosporine, steroïds and mycophenolate. Plasma ICAs, GAD 65, IA2 and C peptide (C-p) levels were monitored. Type II HLA phenotype was determined in donors and recipients.

RESULTS

Patient #1 had high anti-GAD levels (26.5 UI/l) before the IAK, while anti-IA2 and ICA levels were low. After the transplantation, C-p levels increased to 4.9 ng/ml at one month before becoming undetectable at 2 months. GAD levels remained high, ICA and IA2 aAb were undetectable. Patients #2 and #3 did not have significant levels of aAb before the islet transplantation. A slight increase in GAD was observed with each islet transplantation, followed by an overt but transient increase in ICA. IA2 levels remained undetectable. Three months after the transplantation and 2 weeks after the increase of ICA, C-p levels, that were >3.4 ng/ml at one month, fell below 0.2 (N: 0.5-2).

CONCLUSION

The immunosuppressive regimen used in kidney transplantation is unable to control perfectly anti-pancreas aAb production. Moreover, these results seem to indicate that the benefits of sequential islet transplantation lie more in the increased islet mass they provide than in potential immune benefit.

Non-esterified fatty acids are deleterious for human pancreatic islet function at physiological glucose concentration

AIMS/HYPOTHESIS

Whether excess glucose (glucotoxicity) and excess non-esterified fatty acids (lipotoxicity) act synergistically or separately to alter beta-cell function on Type 2 diabetes remains controversial. We examined the influence of non-esterified fatty acids, with or without concomitant increased glucose concentrations, on human islet function and on the expression of genes involved in lipid metabolism.

METHODS

Human islets isolated from non-diabetic and non-obese donors were cultured with 5.5, 16 or 30 mmol/l glucose, and when appropriate with 1 or 2 mmol/l non-esterified fatty acids. After 48 h, glucose-stimulated insulin secretion, insulin content, triglyceride content and expression of different genes were evaluated.

RESULTS

Non-esterified fatty acids decreased glucose-stimulated insulin secretion, insulin content and increased triglyceride content of human isolated islets, independently from the deleterious effect of glucose. Increased glucose concentrations also decreased glucose-stimulated insulin secretion and insulin content, but had no influence on triglyceride content. Glucose-stimulated insulin secretion of islets appeared to be significantly correlated with their triglyceride content. Glucose and non-esterified fatty acids modified the gene expression of carnitine palmitoyltransferase-I, acetyl-CoA carboxylase, acyl-CoA oxidase and uncoupling protein 2.

CONCLUSION/INTERPRETATION

In our model of isolated human islets, increased glucose and non-esterified fatty acids separately reproduced the two major beta-cell alterations observed in vivo, i.e. loss of glucose-stimulated insulin secretion and reduction in islet insulin content. Our results also suggest that this deleterious effect was, at least in part, mediated by modifications in lipid metabolism gene expression.

Extreme subcutaneous insulin resistance: a misunderstood syndrome

Extreme subcutaneous insulin resistance (SIR) is a rare syndrome characterized by severe resistance to subcutaneous insulin with normal intravenous insulin sensitivity. Its pathophysiology is unknown, though an increased insulin degrading activity has been suggested. We report the case of a 35 year-old female patient with type I diabetes since the age of 3. Despite five shots of insulin/day, the patient progressively developed permanent ketosis related to severe acquired SIR with insulin doses as high as 500 U/day. Subcutaneous infusion of insulin and lispro insulin through an external pump did not improve resistance: HbA(1c) levels remained between 14 and 18% (N<6.5%). After numerous ketoacidotic episodes, continuous ambulatory intravenous insulin infusion was attempted through a central port due to a lack of peripheral venous access. HbAlc improved (8.5%) and daily insulin needs decreased to below 40U. However, the treatment had to be discontinued because of thrombosis and infection at different times. Intraperitoneal insulin infusion with an external pump was then proposed. HbAlc improved to 8% during 18 months but several episodes of catheter infection and encapsulation led to its removal. An intraperitoneal pump was surgically implanted, leading to the stabilization of HbA(1c) to around 8%. An insulin degradation assay did not demonstrate any excess of insulin degrading activity in the patient's or controls' subcutaneous tissue; nevertheless, excessive amounts of insulin were found in the patient's derm compared to controls. This case report of acquired SIR raises the question of its treatment and mechanisms. Regarding treatment, intraperitoneal delivery of insulin appears to be the best solution, but the mechanisms underlying SIR still remain unclear.