Impact of deprivation on hospital efficiency and financial balance in paediatrics

Background

In healthcare systems where hospital tariffs are based on average national length of stay (LOS), deprived patients may be a source of inefficiency for hospitals as deprivation has been shown to be associated with increased LOS. They may also negatively impact hospitals’ financial balance as few hospital payment methods include deprivation. Our objective was to study the impact of deprivation on hospital efficiency and financial balance.

Methods

A study was carried out using an exhaustive national hospital discharge database. All inpatient stays in mainland France between 2012 and 2014 by children over 28 days and under 18 in hospitals with a paediatric ward were included. Deprivation was estimated with an ecological deprivation index divided into national quintiles. Efficiency was assessed by variations in patients’ LOS compared to different mean national LOS (paediatric LOS, LOS of admissions for a similar condition...). Financial balance was assessed at the admission level through the ratio of production costs and revenues and at the hospital level with the difference between all revenues and production costs for said hospital. Multivariate models assessed the association between those indicators and deprivation.

Results

4,124,510 inpatient stays were included. LOS was shorter than national means for less deprived patients and longer for the more deprived, and the difference was higher for diagnosis-related groups (DRGs) that included both adult and paediatric patients compared to paediatric-only DRGs. The multivariate model confirmed those significant associations. Deprivation also had a significant impact on hospitals’ financial balance, especially for hospitals with a percentage of paediatric patients in the two most deprived quintiles between 20% and 60%.

Conclusions

Measures to reform hospital payment methods must be encouraged to improve resource allocation efficiency and equity in access to good paediatric care.

Key messages

A reform of hospital funding to better account for deprivation is needed. A modulation of tariffs using an allocation key at the patient level must be considered to mitigate the effect of deprivation. DRGs specific to children should be encouraged to become the norm rather the exception to provide an adequate picture of resources used during admission and therefore an appropriate tariff.

Dental caries and enamelin haplotype

In the literature, the enamelin gene ENAM has been repeatedly designated as a possible candidate for caries susceptibility. Here, we checked whether ENAM variants could increase caries susceptibility. To this aim, we sequenced coding exons and exon-intron boundaries of ENAM in 250 children with a severe caries phenotype and in 149 caries-free patients from 9 French hospital groups. In total, 23 single-nucleotide polymorphisms (SNPs) were found, but none appeared to be responsible for a direct change of ENAM function. Six SNPs had a high minor allele frequency (MAF) and 6 others were identified for the first time. Statistical and evolutionary analyses showed that none of these SNPs was associated with caries susceptibility or caries protection when studied separately and challenged with environmental factors. However, haplotype interaction analysis showed that the presence, in a same variant, of 2 exonic SNPs (rs7671281 and rs3796704; MAF 0.12 and 0.10, respectively), both changing an amino acid in the protein region encoded by exon 10 (p.I648T and p.R763Q, respectively), increased caries susceptibility 2.66-fold independent of the environmental risk factors. These findings support ENAM as a gene candidate for caries susceptibility in the studied population.

Common SNPs of AmelogeninX (AMELX) and dental caries susceptibility

Genetic approaches have shown that several genes could modify caries susceptibility; AmelogeninX (AMELX) has been repeatedly designated. Here, we hypothesized that AMELX mutations resulting in discrete changes of enamel microstructure may be found in children with a severe caries phenotype. In parallel, possible AMELX mutations that could explain resistance to caries may be found in caries-free patients. In this study, coding exons of AMELX and exon-intron boundaries were sequenced in 399 individuals with extensive caries (250) or caries-free (149) individuals from nine French hospital groups. No mutation responsible for a direct change of amelogenin function was identified. Seven single-nucleotide polymorphisms (SNPs) were found, 3 presenting a high allele frequency, and 1 being detected for the first time. Three SNPs were located in coding regions, 2 of them being non-synonymous. Both evolutionary and statistical analyses showed that none of these SNPs was associated with caries susceptibility, suggesting that AMELX is not a gene candidate in our studied population.

Phenotypic homogeneity and genotypic variability in a large series of congenital isolated ACTH-deficiency patients with TPIT gene mutations

CONTEXT

Congenital isolated ACTH deficiency (IAD) is a rare disease characterized by low plasma ACTH and cortisol levels and preservation of all other pituitary hormones. This condition was poorly defined before we identified TPIT, a T-box transcription factor with a specific role in differentiation of the corticotroph lineage in mice and humans, as its principal molecular cause.

OBJECTIVE

We have enlarged our series of IAD patients to better characterize the phenotype and the genotype of this rare disease.

DESIGN

Each exon of the TPIT gene was amplified and sequenced in IAD patients without any identified cause. A functional analysis of each new TPIT mutation was performed.

RESULTS

We described the largest series of 91 IAD patients and identified three distinct groups: neonatal onset complete or partial IAD or late onset IAD. We did not identify any TPIT mutation in patients with partial or late-onset IAD. However, we found a TPIT mutation in 65% of patients with neonatal-onset complete IAD. These patients are homozygous or compound heterozygous for TPIT mutations, and their parents are healthy heterozygous carriers. We identified nine new mutations: four missense, one one-nucleotide deletion, three splice-site mutations, and one large deletion. TPIT mutations lead to loss of function by different mechanisms, such as non-sense-mediated mRNA decay, abnormal mRNA splicing, loss of TPIT DNA binding or protein-protein interaction defects.

CONCLUSION

TPIT mutations are responsible for two thirds of neonatal-onset complete IAD but can not be detected in partial or late-onset IAD.

Medullary thyroid carcinoma identified within the first year of life in children with hereditary multiple endocrine neoplasia type 2A (codon 634) and 2B

CONTEXT

Early prophylactic thyroidectomy in patients with multiple endocrine neoplasia (MEN) type 2 offers the best chance for a normal life expectancy.

OBJECTIVE

To analyze the results of thyroidectomy performed during the first year of life in six patients with MEN 2A (codon 634) or MEN 2B (codon 918) syndrome.

DESIGN AND SETTING

A university hospital-based prospective study from 2001 to 2008.

SUBJECTS AND METHODS

Six family members affected either by MEN 2A (n=3) or MEN 2B (n=3) syndrome were identified through neonatal genetic screening.

RESULTS

Total thyroidectomy was performed at a median age of 0.8 year in the six patients, with central lymph node dissection in five. Bilateral millimetric medullary thyroid carcinoma (MTC) was found in all patients, with a unilateral lymph node micrometastasis in two of the three MEN 2B patients. Before thyroidectomy, MEN 2B patients had much higher basal serum calcitonin levels than those with MEN 2A and controls. After thyroidectomy, with a median follow-up of 3.3 years, the six patients had no evidence of persistent MTC.

CONCLUSION

Bilateral millimetric MTC may be present during the first year of life in these patients, with lymph node metastases also occurring in MEN 2B patients. These results support a total thyroidectomy at the age of about one year in MEN 2A (codon 634) children with an abnormal serum calcitonin level, and a total thyroidectomy with central neck dissection within the first weeks of life in MEN 2B patients.

Conditional and specific NF-kappaB blockade protects pancreatic beta cells from diabetogenic agents

Type 1 diabetes is characterized by the infiltration of inflammatory cells into pancreatic islets of Langerhans, followed by the selective and progressive destruction of insulin-secreting beta cells. Islet-infiltrating leukocytes secrete cytokines such as IL-1beta and IFN-gamma, which contribute to beta cell death. In vitro evidence suggests that cytokine-induced activation of the transcription factor NF-kappaB is an important component of the signal triggering beta cell apoptosis. To study the in vivo role of NF-kappaB in beta cell death, we generated a transgenic mouse line expressing a degradation-resistant NF-kappaB protein inhibitor (DeltaNIkappaBalpha), acting specifically in beta cells, in an inducible and reversible manner, by using the tet-on regulation system. In vitro, islets expressing the DeltaNIkappaBalpha protein were resistant to the deleterious effects of IL-1beta and IFN-gamma, as assessed by reduced NO production and beta-cell apoptosis. This effect was even more striking in vivo, where nearly complete protection against multiple low-dose streptozocin-induced diabetes was observed, with reduced intraislet lymphocytic infiltration. Our results show in vivo that beta cell-specific activation of NF-kappaB is a key event in the progressive loss of beta cells in diabetes. Inhibition of this process could be a potential effective strategy for beta-cell protection.

Breast inflammatory gigantomastia in a context of immune-mediated diseases

CONTEXT

Localized breast lesions have been described in lupic or diabetic patients. However, the description of breast gigantomastia in women presenting with autoimmune diseases has not been reported.

SETTING

The study took place within the Department of Endocrinology and Reproductive Medicine, Necker Hospital, Paris, France.

PATIENTS

We describe eight patients with inflammatory gigantomastia, occurring in a context of immune-mediated diseases: myasthenia, chronic arthritis, or thyroiditis.

MAIN OUTCOME MEASURES

Together with hormonal, immunological, and breast magnetic resonance imaging (MRI) evaluation, breast histology enabled us to perform immunocytochemical and indirect immunofluorescence studies. Control sera were obtained from patients with (n = 10) and without (n = 7) antinuclear antibodies.

RESULTS

Six of the eight patients developed gigantomastia either at puberty or during pregnancy. Neither a hormonal oversecretion nor a specific immunological pattern was observed. All patients except one presented antinuclear antibodies. Histological study revealed a diffuse, stromal hyperplasia and a severe atrophy of the lobules. A rarefaction of adipocytes was also noted, as previously suggested on MRI. There was a perilobular lymphocytic infiltrate made of CD3+ lymphocytes. Study of sera from five of six cases of gigantomastia showed a nuclear immunofluorescence pattern in normal mammary ductal and lobular glandular epithelium, as well as in kidney and intestine epithelial cells. In control sera, a nuclear signal was observed only when antinuclear antibodies were present.

CONCLUSIONS

We suggest that breast tissue may be a target tissue in autoimmune diseases, this process being favored by the hormonal milieu. However, the precise mechanism of such association is not individualized. The fact that stromal hyperplasia is the main histological feature justifies the search for the involvement of growth factors in such a process.

Destruction of conditional insulinoma cell lines in NOD mice: a role for autoimmunity

AIMS/HYPOTHESIS

betaTC-tet (H2(k)) is a conditional insulinoma cell line derived from transgenic mice expressing a tetracycline-regulated oncogene. Transgenic expression of several proteins implicated in the apoptotic pathways increase the resistance of betaTC-tet cells in vitro. We tested in vivo the sensitivity of the cells to rejection and the protective effect of genetic alterations in NOD mice.

METHODS

betaTC-tet cells and genetically engineered lines expressing Bcl-2 (CDM3D), a dominant negative mutant of MyD88 or SOCS-1 were transplanted in diabetic female NOD mice or in male NOD mice with diabetes induced by high-dose streptozotocin. Survival of functional cell grafts in NOD-scid mice was also analyzed after transfer of splenocytes from diabetic NOD mice. Autoreactive T-cell hybridomas and splenocytes from diabetic NOD mice were stimulated by betaTC-tet cells.

RESULTS

betaTC-tet cells and genetically engineered cell lines were all similarly rejected in diabetic NOD mice and in NOD-scid mice after splenocyte transfer. In 3- to 6-week-old male NOD mice treated with high-dose streptozotocin, the cells temporarily survived, in contrast with C57BL/6 mice treated with high-dose streptozotocin (indefinite survival) and untreated 3- to 6-week-old male NOD mice (rejection). The protective effect of high-dose streptozotocin was lost in older male NOD mice. betaTC-tet cells did not stimulate autoreactive T-cell hybridomas, but induced IL-2 secretion by splenocytes from diabetic NOD mice.

CONCLUSION/INTERPRETATION

The autoimmune process seems to play an important role in the destruction of betaTC-tet cells in NOD mice. Genetic manipulations intended at increasing the resistance of beta cells were inefficient. Similar approaches should be tested in vivo as well as in vitro. High dose streptozotocin influences immune rejection and should be used with caution.

Effect of gonadotropin-releasing hormone agonist treatment in boys with central precocious puberty: final height results

OBJECTIVE

The small number of boys present in most studies on final height (FH) after gonadotropin-releasing hormone agonist (GnRHa) treatment for central precocious puberty (CPP) offers difficulties in the evaluation of the effects of treatment on FH in males.

METHOD

We therefore combined FH data from The Netherlands, Italy and France to study the effect of GnRHa treatment in a large group of 26 boys with CPP.

RESULTS

The mean chronological age at the start of treatment was 7.6 +/- 2.0 (SD) years, bone age (BA) was 11.0 +/- 2.1 years. All boys were treated with depot formulations of the GnRHa triptorelin with established gonadal suppression for a mean treatment period of 4.7 +/- 2.1 years. FH was 172.9 +/- 6.6 cm. FH standard deviation score (SDS) was -0.66 +/- 1.22, not significantly different from the target height SDS of -0.23 +/- 0.75. FH-SDS was significantly lower in the subgroup of 12 patients with organic CPP compared to patients with idiopathic CPP (-1.34 +/- 1.06 vs. -0.08 +/- 1.06, respectively; p = 0.01), but no difference in height gain was observed. The mean estimated height gain, defined as the difference between predicted and actual adult height was 6.2 +/- 8.7 cm using the average tables of Bayley and Pinneau, and 0.3 +/- 8.6 cm using the BA advance adjusted tables. Regional differences in height gain were observed between the different countries, reflecting different local practices.

CONCLUSION

We conclude that GnRHa treatment in boys results in a FH close to target height.

[Two cases of mineralocorticoids deficiency as first endocrine manifestation of APECED syndrome]

The Authors report two cases of APECED syndrome (Auto-immune Polyendocrinopathy-Candidiasis-Ectodermal Dystrophy) revealed by hyponatremia due to isolated mineralocorticoids deficiency. Such cases illustrate the variable endocrine features revealing the syndrome. The mechanisms underlying the auto-immune destruction of the adrenals are discussed.

Effects of prolonged administration of ultralente insulin on fasting and postbreakfast beta-cell function in normal adults

Treatment with small doses of subcutaneous insulin is being investigated as a possible approach to prevent type 1 diabetes in humans. The mechanism of prophylactic insulin therapy could involve the inhibition of beta-cell secretory activity and/or the initiation of an active immunoregulatory process. To evaluate the pure metabolic effect of exogenous insulin, the present study assessed whether daily subcutaneous administration of ultralente insulin alters beta-cell function in normal adults. Fourteen healthy adults were randomized to receive 0.2 U/kg x d ultralente insulin (Ultratard; Novo Nordisk, Bagsvaerd, Denmark) or placebo subcutaneously once daily for 30 days. Plasma glucose, C-peptide, and insulin concentrations were measured in the fasting state and 1 hour after a standardized breakfast, during treatment and during a recovery period of 10 days. Insulin administration induced a 15% to 40% decrease of fasting plasma C-peptide. In contrast, postbreakfast plasma C-peptide increased by 40% to 90% in subjects receiving insulin. Fasting and postbreakfast C-peptide concentrations were significantly different between groups during the injection period after adjustment for baseline concentrations (P < .05, ANOVA with repeated measures). These alterations disappeared 3 days after cessation of insulin treatment. The present regimen of exogenous insulin alters endogenous insulin secretion in normal subjects. Instead of the expected beta-cell rest, the effect appeared to be dual, with insulin secretion decreasing in the basal state and increasing after meals.

Oral insulin administration and residual beta-cell function in recent-onset type 1 diabetes: a multicentre randomised controlled trial. Diabète Insuline Orale group

BACKGROUND

Oral administration of autoantigens can slow the progression of beta-cell destruction in non-obese diabetic mice. We investigated whether oral administration of recombinant human insulin could protect residual beta-cell function in recent-onset type 1 diabetes.

METHODS

We enrolled 131 autoantibody-positive diabetic patients aged 7-40 years within 2 weeks of diagnosis (no ketoacidosis at diagnosis, weight loss <10%, polyuria for <6 weeks). They were randomly assigned 2.5 mg or 7.5 mg oral insulin daily or placebo for 1 year, in addition to subcutaneous insulin therapy. Serum C-peptide concentrations were measured in the fasting state and after stimulation, to assess beta-cell function. Autoantibodies to beta-cell antigens were assayed. Analyses were by intention to treat.

FINDINGS

Baseline C-peptide and haemoglobin A1c concentrations were similar in the three groups. During follow-up, there were no differences between the groups assigned 2.5 mg or 7.5 mg oral insulin or placebo in subcutaneous insulin requirements, haemoglobin A1c concentrations, or measurements of fasting (mean at 12 months 0.18 [SD 0.17], 0.17 [0.17], and 0.17 [0.12] nmol/L) or stimulated C-peptide concentrations (glucagon-stimulated 0.39 [0.38], 0.37 [0.39], and 0.33 [0.24] nmol/L; meal-stimulated 0.72 [0.60], 0.49 [0.49], and 0.57 [0.51 nmol/L]. Neither age nor C-peptide concentration at entry influenced treatment effects. No differences were seen in the time-course or titres of antibodies to insulin, glutamic acid decarboxylase, or islet antigen 2.

INTERPRETATION

At the doses used in this trial, oral administration of insulin initiated at clinical onset of type 1 diabetes did not prevent the deterioration of beta-cell function.

Soluble leptin receptor in serum of subjects with complete resistance to leptin: relation to fat mass

Leptin resistance and obesity have been related to mutations of the leptin receptor gene in rodents and, recently, in a consanguineous family. The latter mutation results in a receptor lacking transmembrane and intracellular domains. Homozygous and heterozygous individuals with this mutation had serum leptin levels higher than expected, given their BMIs: 600, 670, and 526 ng/ml and 145, 362, 294, 240, and 212 ng/ml, respectively. Their serum leptin was fractionated by gel filtration: >80% was present as a high-molecular size complex vs. 7.5% in the nonmutated sister. Western blot analysis showed a band at 146 kDa reacting specifically with an antibody directed against the leptin receptor ectodomain. In 10 obese control subjects, as in the mutated patients, free leptin levels correlated with BMI (r = 0.70, P = 0.0011) and reflected fat mass, regardless of leptin receptor functioning. In the patients, bound leptin levels correlated with BMI (r = 0.99, P = 0.0002) and were related to the number of mutated alleles. These data demonstrate that the truncated receptor is secreted into blood and binds the majority of serum leptin, markedly increasing bound and total leptin. Free serum leptin was similarly correlated with BMI in the mutated and nonmutated obese individuals, providing evidence that the relationship between BMI and circulating free leptin is preserved in this family. This finding suggests that the leptin receptor itself may not be specifically involved in the control of leptin secretion, and it supports the concept of relative resistance to leptin in common obesity.

Pharmacokinetics and pharmacodynamics of GnRH agonists: clinical implications in pediatrics

Since 1981, GnRH agonist administration has been the treatment of choice for central precocious puberty. Continuous administration of the agonist, instead of permanently stimulating gonadotropin secretion, deeply suppresses LH and FSH levels and induces a marked inhibition of gonadal activity and regression of clinical symptoms. This inhibitory effect is due both to specific kinetic parameters relative to natural GnRH, and to marked alterations of the biosynthetic pathways of gonadotropin subunits. The half disappearance time of infused agonists is 3-10 fold that of natural GnRH. This means that the residence time of GnRH agonists is significantly longer than that of GnRH. The resistance of agonist to enzymatic degradation, mainly due to the substitution of a hydrophobic D-amino acid for glycine 6, is one of the factors involved in the increased availability of GnRH superagonists. The paradoxical effects of GnRH superagonists are still incompletely understood. In children long-term treated with depot formulations of triptorelin or leuprorelin, alpha-subunit secretion is markedly increased, and remains sensitive to exogenous GnRH, which demonstrates that the gonadotrophs are not totally desensitized. Despite the sustained stimulation of a-subunit secretion, no deleterious side effects, either during therapy or during post-therapy follow-up, have been reported in children treated with GnRH agonists. It should be noted that alpha-subunit responsiveness to exogenous GnRH decreases progressively after several years of treatment, although it is never completely abolished. On the other hand, LH beta-subunit secretion is suppressed as evidenced by radioimmunoassay of LH beta-subunit in serum chromatographic fractions from children treated with triptorelin. This differential pattern of secretion parallels that of mRNA levels in rat pituitary after in vivo exposure to triptorelin. Both pharmacodynamic and pharmacokinetic data can help diagnose the situations of resistance or escape. The lack of clinical effect of GnRH in the treatment of precocious puberty can be due to true resistance, or to an inappropriate injection schedule, or to abnormal metabolism. Measurement of serum alpha-subunit level, and, if needed, of serum agonist level, generally provides the answer.

[Growth hormone treatment of children with short stature secondary to intrauterine growth retardation]

There is now good evidence that short-term growth hormone treatment improves growth of children with short stature secondary to intrauterine growth retardation. A 3-year treatment with dosages greater than 1.2 U/kg/week allows these children to reach normal height, without any currently known side effect. Long-term efficacy, i.e., improvement of final height, is probable, but depends on the possibility of reconducting the treatment in case of loss of the initial benefits. The possible effect of treatment on puberty is presently unknown and will need special attention when treated children reach pubertal age.

[Catch-up growth in growth hormone deficit children treated with GH since the first year of life]

Long-term effects of growth hormone (GH) treatment were studied in 59 GH deficient (GHD) children, whose treatment was started before the age of 1 year, during the period 1978-1992, under the supervision of the France-Hypophyse Association. Mean duration of treatment was 8 +/- 3.6 years. At the last evaluation, 20 patients (34%) had a height above normal mean for age, and 50 (85%) had a height above the second lower standard deviation (SD) for age. Final height prediction performed in 29 patients was greater than target size (-0.35 +/- 1.4 SD vs -0.56 +/- 0.79 SD). These results show that early treatment of GHD infants allows normal statural growth in the majority of the cases; in addition, they underline the importance of early diagnosis of GH deficiency.

Gonadotropin releasing hormone agonist treatment for central precocious puberty

Several methodological problems complicate the evaluation of final statural height (FH) benefit after treatment with gonadotropin releasing hormone (GnRH) agonists for central precocious puberty (CPP). Since no controlled study has been performed, we have to rely on indirect methods, comparison with predicted height or with historical controls. FH of 58 girls, uniformly treated with triptorelin slow release formulation (triptorelin-SR, Decapeptyl((R))) for CPP were compared with predicted height before treatment and with FH of an historical group of patients not treated with GnRH agonist. The comparison with predicted height revealed an improvement of 4.8 +/- 5.8 cm; comparison with the historical control group showed a mean improvement of 8.3 cm. The post-treatment growth spurt (DeltaFH - height at the end of treatment) was a strong predictor of FH in multivariate analysis. The data suggest that continuing treatment beyond the age of 11 in girls does not improve and could actually decrease FH.

Resistance to the lipolytic action of epinephrine: a new feature of protein Gs deficiency

Deficiency of protein Gs (Gs; OMIM no.103580), the stimulatory regulator of adenylyl cyclase, is associated with resistance to PTH and other hormones, sc calcifications, short stature, and skeletal defects (Albright's hereditary osteodystrophy). It is caused by heterozygous loss of function mutations in GNAS 1, the gene encoding the alpha-subunit of Gs. Obesity is a classical feature of patients with Gs deficiency, but the mechanism leading to fat accumulation has not been elucidated. We measured glycerol flux, using a nonradioactive tracer dilution approach, to analyze the lipolytic response to epinephrine in 6 patients with Gs deficiency and PTH resistance and compared it to six age-matched normal controls and nine massively obese children. Basal glycerol production was reduced by 50%, and lipolytic response to epinephrine was reduced by 67%, in Gs-deficient children, as compared with controls. The degree of impairment of lipolysis was similar in Gs-deficient children who were only moderately overweight and in morbidly obese children. These findings extend the spectrum of hormonal resistance in Gs deficiency. Besides beta-adrenergic receptors, Gs protein itself should be examined as a possible step involved in the decreased lipolysis observed in common obesity.

Lack of effect of GnRH agonists on final height in girls with advanced puberty: a randomized long-term pilot study

GnRH agonists improve final height in girls with "true" precocious puberty. To test if a comparable effect can be obtained in older girls, we performed a long-term controlled study in 30 caucasian girls whose puberty started between 8.4 and 10 yr (9.4 +/- 0.1 yr), a variant of normal called "advanced" puberty. At entry into trial, these girls had clinical, biological, and sonographic manifestations of puberty and a bone age greater than 10.9 yr. They were randomized 2:1 to receive 3.75 mg triptorelin im every 4 weeks for 2 yr (n = 20, group I) or no treatment (n = 10, group II). Mean height at inclusion was 135.2 +/- 4.3 cm (+0.6 SDS) in group I, 136.1 +/- 4.2 cm (+0.8 SDS) in group II, with target height 157.6 +/- 4.3 cm (group I) and 157.8 +/- 4.7 cm (group II), and predicted height (Bayley-Pinneau) 154.1 +/- 3.9 cm and 155.2 +/- 3.7 cm. Although GnRH agonists transiently delayed sexual maturation as well as bone age and growth rate, they had no clear-cut long-standing effect, and final height was comparable in treated (157.6 +/- 4.0 cm) and untreated girls (156.1 +/- 5.3 cm) (NS).

Final height after long-term treatment with triptorelin slow release for central precocious puberty: importance of statural growth after interruption of treatment. French study group of Decapeptyl in Precocious Puberty

The impact of treatment of central precocious puberty (CPP) with GnRH agonists on final statural height (FH) remains controversial, and guidelines on the optimal time point for interruption of these treatments have not been established. We analyzed the long term results of 58 girls and 8 boys uniformly treated with triptorelin slow release formulation (Decapeptyl, triptorelin-SR) for CPP and compared their FH with predicted height before treatment and with the FH of a historical group of patients not treated with GnRH agonist. The FH SD score was close to 0 and was not different from the genetic target height. In girls, FH was improved by 4.8 +/- 5.8 cm compared with predicted height before treatment and by 8.3 cm by comparison with a historical group. In boys, comparison with a historical group revealed a 13.7-cm improvement, whereas predicted height before treatment was similar to FH. Three variables were independently associated with FH in girls: the bone age/statural age ratio at the onset of treatment (negatively), the height SD score at the end of treatment, and the posttreatment growth spurt (delta FH - height at the end of treatment). The influence of the posttreatment growth spurt, itself dependent on age and bone age at the interruption of treatment, suggests that continuing treatment beyond the age of 11 yr in girls does not improve and could actually decrease FH. This point should be evaluated in a formal controlled trial.

T-cell response to proinsulin and insulin in type 1 and pretype 1 diabetes

Insulin-dependent diabetes mellitus (IDDM) results from the selective destruction of pancreatic beta cells by a T cell-mediated autoimmune process. Insulin and proinsulin are the only known beta cell-specific autoantigens. Using short-term cultures of freshly isolated peripheral blood mononuclear cells, we evaluated T-cell responses to proinsulin and to insulin in IDDM patients and individuals at risk for IDDM. A proliferative T-cell response to proinsulin was observed in only 2 of 26 recent-onset IDDM subjects and 2 of 12 long-standing IDDM subjects and was associated with a proliferative response to insulin. In contrast, 5 of 13 islet cell autoantibody-positive first-degree relatives of IDDM patients showed a proliferative response to proinsulin alone, 3 of 13 to insulin alone, and 1 of 13 to both insulin and proinsulin. Overall, 9 of 13 ICA-positive first-degree relatives responded to either proinsulin or insulin. We observed an inverse relationship between antiinsulin antibodies and T-cell responses to insulin in ICA-positive first-degree relatives but not in long-standing IDDM patients. Our data indicate that proinsulin is a major antigen in IDDM and, further, illustrate the difference between the autoimmune response to insulin and the immune response to exogenous insulin.

Long-term results of GH therapy in GH-deficient children treated before 1 year of age

OBJECTIVES

To evaluate the long-term effects of GH therapy in early diagnosed GH-deficient patients treated before 1 year of age.

STUDY DESIGN

We studied all 59 patients (33 males) recorded by Association France-Hypophyse and treated with GH (0.50+/-0.15 IU/kg (S.D.) per week) before 1 year of age. Clinical presentation and growth parameters under GH treatment were analyzed.

RESULTS

Neonatal manifestations of hypopituitarism were frequent: hypoglycemia (n=50), jaundice (n=25) and micropenis (n=17/33). Although birth length was moderately reduced (-0.9+/-1.4), growth retardation at diagnosis (5.8+/-3.8 months) was severe (-3.5+/-1.9 standard deviation scores (SDS)). Fifty patients (85%) had thyrotropin and/or corticotropin deficiency. After a mean duration of GH therapy of 8.0+/-3.6 years, change in height SDS was +3.11+/-2.06 S.D., exceeding 4 SDS in 19 patients. Only 9 patients (15%) did not reach a height of -2 S.D. for chronological age and 20 patients (34%) exceeded their target height. Pretreatment height SDS was independently associated with total catch-up growth.

CONCLUSION

Conventional doses of GH allow normalization of height in patients with early GH deficiency and treatment.

Novel mutations in the thiazide-sensitive NaCl cotransporter gene in patients with Gitelman syndrome with predominant localization to the C-terminal domain

Gitelman syndrome (familial hypokalemia-hypomagnesemia syndrome) is an autosomal recessive inherited renal disorder characterized by defective tubular reabsorption of magnesium and potassium. In this study a group of 18 unrelated and 2 related Gitelman patients, collected from six different countries have been screened for mutations in the human thiazide-sensitive sodium-chloride cotransporter (SLC12A3) gene. Fourteen novel SLC12A3 mutations are presented along with six mutations described earlier, and three neutral polymorphisms. Among the tested patients are two who carry a total of three heterozygous SLC12A3 mutations. Two-thirds of the total number of mutant SLC12A3 alleles are amino acid substitutions. Most SLC12A3 gene mutations, 14 out of a total of 20, are localized at the intracellular carboxy-terminal domain of the NCCT protein. The pathogenicity of individual SLC12A3 mutations is based upon their predicted effect on SLC12A3 protein, and segregation in family members. Evolutionary conservation of substituted amino acid residues and their frequency in control chromosomes is presented. Identical mutations have been found in Gitelman families from different geographical origin, suggesting ancient mutations originating from a common ancestor. As yet, we have not found any evidence for a possible genotype-phenotype correlation.

Low dose linomide in Type I juvenile diabetes of recent onset: a randomised placebo-controlled double blind trial

The quinoline-3-carboxamide, linomide, protects non-obese diabetic mice from diabetes. The effects of linomide on insulin needs and beta cell function were studied in recent juvenile Type I diabetes in a double-blind trial. Patients with recent onset diabetes were randomly assigned to treatment with a fixed dose of 2.5 mg linomide (42 patients) or placebo (21 patients) for 1 year, in addition to insulin and diet. Glycated haemoglobin was 10-15% lower at 9 months (p = 0.003) and 12 months (p < 0.05) in the linomide group. The insulin dose was 32-40% smaller in the linomide group at 3 (p < 0.03), 6 (p < 0.02), 9 (p < 0.001) and 12 months (p = 0.01). Insulin doses correlated negatively with C peptide values (p = 0.001-0.002). The trend for higher C peptide values in the linomide group did not reach significance. In a post hoc subgroup analysis performed in 40 patients (25 from the linomide group and 15 from the placebo group) who still had detectable residual beta cell function at entry, linomide was associated with 45-59% higher C peptide value at 6 months (p < 0.05), 9 months (p < 0.05) and 12 months (p < 0.05). The main adverse effects of linomide were mild transitory anaemia (45 vs 10% in the linomide and placebo groups), thrombocytopenia (24 vs 10%), and mild joint discomfort (45 vs 5%) with no clinical signs. In conclusion, low-dose linomide reduced the insulin needs in patients with juvenile Type I diabetes of recent onset and improved beta cell function in patients who still had detectable beta cell function at entry. These results support further clinical and experimental studies to define the effects of linomide in Type I diabetes provided the safety of linomide is reliably established.

Factors associated with glycemic control. A cross-sectional nationwide study in 2,579 French children with type 1 diabetes. The French Pediatric Diabetes Group

OBJECTIVE

To determine on a large scale the multiple medical and nonmedical factors that influence glycemic control in the general population of children with diabetes, we performed a nationwide French cross-sectional study.

RESEARCH DESIGN AND METHODS

We enrolled 2,579 patients aged 1-19 years with type 1 diabetes of > 1 year's duration. The study was center based: 270 centers were identified, 206 agreed to participate, and 147 included at least 90% of their patients. Questionnaires were completed by physicians interviewing patients and family, and HbA1c measurements were centralized. To identify explanatory variables for HbA1c level and frequency of severe hypoglycemia, we performed multiple regression analysis using all the quantitative variables collected and stepwise logistic regression for the qualitative variables.

RESULTS

Mean HbA1c value for the whole population was 8.97 +/- 1.98% (normal 4.7 +/- 0.7% [SD]). Only 19 children (0.7%) had ketoacidosis during the 6 months before the study, whereas 593 severe hypoglycemia events occurred in 338 children (13.8%). Control was better in university-affiliated hospitals and centers following > 50 patients, reflecting the importance of access to experienced diabetologists. Children had a mean of 2.3 injections, allegedly performed 2.8 glucose measurements per day, and were seen an average of 4.6 times per year at the center. In the multiple regression analysis, 94% of the variance of HbA1c was explained by our pool of selected variables, with the highest regression coefficient between HbA1c and age (Rc = 0.43, P < 0.0001), then with daily insulin dosage per kilogram (Rc = 0.28, P < 0.0001), mother's age (Rc = 0.26, P < 0.0001), frequency of glucose measurements (Rc = 0.21, P < 0.0001), and diabetes duration (Rc = 0.14, P < 0.0001). Logistic regression identified quality of family support and dietary compliance, two related qualitative and possibly subjective variables, as additional explanatory determinants of HbA1c. The frequency of severe hypoglycemia was 45 per 100 patient-years and correlated with diabetes duration, but not with HbA1c levels or other variables.

CONCLUSIONS

Although overall results remain unsatisfactory, 33% of studied French children with type 1 diabetes had HbA1c < 8%, the value obtained in Diabetes Control and Complications Trial adolescents treated intensively. Diabetes management in specialized centers should be encouraged.

Near normalization of final height with adapted doses of growth hormone in Turner's syndrome

An adapted GH dose regimen was evaluated in 14 untreated patients with Turner's syndrome. The initial GH dose (0.7 U/kg.BW) was increased by 0.7 U/kg.BW, up to a maximum of 2.1 U/kg.BW, when growth velocity (GV) declined to less than 200% of the pretreatment level. These patients were compared to a group of 17 patients with similar initial characteristics, who received a fixed dose of 0.9 U/kg.BW GH. Tolerance to both GH regimens was excellent. The adapted GH doses only partially prevented the waning effect observed with conventional doses of GH, and the initial goal of doubling GV was only achieved in 42% of the 112 patient-semesters. Doubling the GH dose from 0.7 to 1.4 U/kg.BW increased the GV by 1.6 +/- 1.8 cm/yr (P < 0.006); increasing the GH dose from 1.4 to 2.1 U/kg.BW increased GV by 0.8 +/- 1.3 cm/yr (P = NS). The overall height gain during the 4-yr trial was 25.6 +/- 3.9 cm in the adapted dose group and 21.8 +/- 3.9 cm in the conventional group (P < 0.02). Final height (FH) results were obtained in 12 of 14 patients in the adapted dose group and all 17 patients in the conventional group and compared to the predicted FH using Lyon's method. The estimated height benefit was 10.6 +/- 3.8 cm in the adapted dose group compared to 5.2 +/- 3.7 cm in the conventional group (P < 0.01). Eighty-three percent of the patients in the adapted dose group had an FH superior or equal to -2 SD score for the general population compared to 29% in the conventional group. In conclusion, a marked increment in the GH dose in girls with Turner's syndrome associated with a relatively late age at introduction of estrogen therapy brought 83% of the patients into the lower range of the normal height distribution of the general population.

Short stature associated with intrauterine growth retardation: final height of untreated and growth hormone-treated children

Short term studies have demonstrated the acceleration of growth velocity after the administration of GH in short children born with intrauterine growth retardation (IUGR). We report the final heights of 70 IUGR children whose short stature was attributed to idiopathic GH deficiency (peak plasma GH <10 ng/mL at 2 provocative tests) and treated with GH at a mean dosage of 0.4 +/- 0.1 U/kg x week during an average of 4.6 +/- 2.5 yr. They were compared to a control group of 40 untreated short children born with IUGR, without GH deficiency. At the time of evaluation, age, auxological data, and pubertal status were similar in the 2 groups (height, -2.9 +/- 0.8 and -2.8 +/- 0.7 SD score). Final heights were comparable in both groups of children (-2 +/- 0.7 and -2.2 +/- 1.1 SD score). A multivariate analysis identified 4 independent predictors of final height, namely target height, age and body mass index at evaluation, and GH treatment. Treatment was associated with a gain of 0.6 SD score, suggesting a final height gain of about 3.4 cm. Fifty-three of 70 treated children were reevaluated after completion of growth, and 43 of 53 had a peak plasma GH level of 10 ng/mL or more. Auxological characteristics of these 53 patients were not different from those of nonreevaluated patients. We believe that the transient character of the GH deficiency in most patients and the nonstringent initial criteria used for the diagnosis of GH deficiency render the spontaneous growth potentials identical in the 2 groups of patients. Our data, therefore, suggest that GH treatment at this dosage has a limited effect on the final height of short children born with IUGR.

Pharmacological testing for the diagnosis of growth hormone deficiency

Evaluation of growth hormone (GH) secretion using pharmacological GH stimulation tests (GHSTs) remains current practice, although the reliability of GHSTs has been questioned and many pitfalls have been pointed out. We have analysed all the 6,373 GHSTs which led to the initiation of GH therapy in 3,233 children treated in France from 1973 to 1989. Eleven different pharmacological tests were used, and 62 out of the 66 theoretical pairs of tests were used at least once. The most frequent combination of tests was used in 12.7% of patients. Reliability of GH peak measured by comparing the results of two tests in the same patient was poor, as measured by intraclass correlation coefficients (all under 0.8). Multivariate analysis identified several parameters positively or negatively associated with peak plasma GH. We believe that several of these factors (i.e. weight standard deviation score (SDS), genetic target height SDS and nature of the agent) identify biases in the diagnosis of GH deficiency (GHD). In addition, we re-evaluated GH secretion in 208 young adults formerly treated with GH for childhood onset GHD. Peak plasma was superior or equal to 10 ng/ml in 81% of patients with former idiopathic GHD. We conclude that the current use of GHSTs as well as the criteria for idiopathic childhood GHD should be questioned.

Growth hormone therapy for Turner syndrome: evidence for benefit

Growth hormone (GH) is registered for children with Turner syndrome (TS) in several countries. Improving the final heights (FH) is certainly the most worthy goal of therapy, but evaluation of treatment effect is complicated by methodological difficulties. Several series of FH results have now been published, with estimated benefits ranging from 0-9.3 cm, as compared to predicted height before treatment. The majority of studies report height gains of less than 5 cm, but in these studies, GH was started at a relatively late age and used at low doses. Several approaches can be utilized to improve FH results in TS, including early initiation of GH therapy, increased or optimized GH dose regimens, or optimization of sexual steroid utilization.

Increased CD5+CD19+ B lymphocytes at the onset of type 1 diabetes in children

The aim of this study was to determine whether the proportion of circulating B cells expressing the differentiative antigen CD5 was increased in children affected by type 1 diabetes, and whether the number of these cells was correlated with the presence of anti-islet cell autoantibodies. Sixteen children affected by insulin-dependent diabetes mellitus (type 1) were investigated for the presence of B lymphocytes bearing the CD5 surface molecule, T-cell-specific activation markers, organ- and nonorgan-specific autoantibodies. The number of CD5+CD19+ cells was higher in type 1 children with a very recent onset of the disease, as compared with patients on insulin therapy for more than 30 days and controls (P < 0.05). No correlation was found between the number of CD5+CD19+ cells and the presence of either organ- or nonorgan-specific autoantibodies. Our results indicate that CD5+CD19+ cells are involved in the pathogenesis of type 1 diabetes in children. A potential immunoregulatory role of this B cell population is discussed.

Growth hormone treatment of children with short stature secondary to intra-uterine growth retardation: effect of 2 years' treatment and 2 years' follow-up

Growth hormone (GH) treatment has been proposed to improve final height in patients with short stature associated with intra-uterine growth retardation (IUGR). In this study, 30 prepubertal patients aged 9.5 +/- 0.9 years with IUGR and normal GH secretion on pharmacological testing were treated with GH. These patients had a mean birth length of -3.11 +/- 0.80 SDS, and mean growth retardation of -2.58 +/- 0.49 SDS for chronological age. GH, 1.4 IU/kg/week (= 0.07 mg/kg/day), was given for 2 years. Height gain (calculated as the difference of height SDS at baseline and after 2 years) was 1.3 +/- 0.4 SD and was not significantly correlated with height SDS or growth velocity at baseline. These data confirm that 2 years of recombinant human GH treatment increases height gain in patients with IUGR. Two years after treatment interruption, mean gain was maintained at +1.08 SDS and 83% of the children had normal height.

Long-term results of growth hormone treatment in France in children of short stature: population, register based study

OBJECTIVES

To describe the growth of children treated with growth hormone and to evaluate the prognostic factors for height at the end of treatment.

DESIGN

Register based cohort study.

SETTING

French national register of all children treated with growth hormone.

SUBJECTS

3233 short stature children (3165 of whom were deficient in growth hormone) who were treated with growth hormone (excluding children with Turner's syndrome) and whose treatment started between 1973 and 1989, last data being recorded in December 1993.

MAIN OUTCOME MEASURES

Annual changes in height, and height at the end of treatment.

RESULTS

Mean height SD score at the end of treatment, after a mean of 4.3 years, was -2, corresponding to gain in mean height SD score of 1 and to a height SD score of 1.1 below target height. In all, 923 children prematurely stopped taking growth hormone treatment, mainly because of insufficient response (insufficient growth) or tiredness. Variables that predicted height at the end of treatment were age, target height, aetiology of short stature, use of puberty inhibitors, and type of growth hormone.

CONCLUSIONS

The outcome of children of short stature with growth hormone deficiency who were treated with growth hormone has been less favourable than initially assumed. Growth hormone treatment has not restored normal growth to these children. The highly demanding nature and high costs of this treatment require an optimised prescription, and this remains to be determined.

Insulin and the prevention of insulin-dependent diabetes mellitus

Insulin deficiency due to autoimmune destruction of pancreatic beta cells (insulin is an autoantigen) is responsible for insulin-dependent diabetes mellitus. Since 1923, substitutive administration of insulin has been used to treat the disease. Surprisingly, initial usage of insulin is associated with partial resumption of insulin secretion in most patients. This phenomenon is intensified by aggressive insulin therapy. When observed at a late phase of destruction, it has been interpreted as an immunomodulatory effect of insulin which is presumed to act either by masking the target of effector cells in the autoimmune reaction (beta cells at rest because of glycaemic normalisation would expose fewer antigens) or by direct action on autoreactive T lymphocytes (which are rich in insulin receptors). There could also be a direct beneficial effect on anti-apoptotic or pro-regenerative beta cells. Efficient prevention of diabetes has been achieved by administration of parenteral insulin to non-obese diabetic (NOD) mice. Certain sequences of the B chain appear to be responsible for this effect, which seems to be immunomediated. Some preliminary data from the groups of G. Eisenbarth and N. MacLaren have suggested that this effect could be obtained in man by administering small doses of subcutaneous insulin to prediabetic patients. Two trials have been under way since 1994: DPT1 (a non-randomised trial concerning children and adults at high risk) in the United States, and EPP-SCIT (a randomised trial concerning children at very high risk) in Europe. Another approach has also been attempted in diabetes as well as other diseases with an organ-specific autoimmune reaction (SEP, PR) i.e. oral administration of an antigen present at the reaction site. A positive effect has been shown by the group of H. Weiner in the NOD mouse in which islet infiltration was reduced and diabetes prevented by "oral tolerisation" with insulin. Oral insulin is easy to use in therapeutic studies and is currently being administered in two trials: DPT1 (prediabetic children and adults at moderate risk) in the United States, and DIOR (recently diabetic children and adults) in France. However, recent experimental data suggest that oral administration of an antigen in certain artificial circumstances can trigger an autoimmune reaction in the animal, which would indicate that due caution should be exercised in trials involving prediabetic patients.

Growth hormone testing for the diagnosis of growth hormone deficiency in childhood: a population register-based study

Evaluation of GH secretion using pharmacological GH stimulation tests (GHST) remains a current practice, although the reliability of GHST has been questioned, and many pitfalls have been pointed out. We have analyzed all of the 6373 GH stimulation tests that led to the initiation of GH therapy in 3233 children treated in France from 1973-1989. Tests and GH measurements were performed by individual centers and collected by the Association France-Hypophyse. GH deficiency (GHD) was due to craniospinal irradiation (11%), was due to organic causes or associated with multiple deficiencies (22%), or was considered idiopathic (65%); 2% of the patients were considered non-GHD. Eleven different pharmacological tests were used, and 62 of the 66 theoretical pairs of tests were used at least once. The most frequent combination of tests (ornithine in one instance and insulin in another) was used in 12.7% of patients. The reliability of the GH peak measured by comparing the results of 2 tests in the same patient was poor, as measured by intraclass correlation coefficients below 0.8. Multivariate analysis identified several parameters positively or negatively associated with peak plasma GH: calendar year of initiation of treatment, etiology of GHD, height SD score, bone age SD score, puberty, weight SD score, genetic target height SD score, and the nature of the pharmacological agent used. We believe that several of these factors (weight SD score, genetic target height SD score, and nature of the agent) identify biases in the diagnosis of GHD. We conclude that GHST should be performed with a very limited number of agents, interpreted after the establishment of reference values in age-matched normal children, and associated with other clinical and biochemical parameters for establishing the diagnosis of GHD.

[Cushing disease in children and in adolescents. Therapeutic results]

BACKGROUND

Trans-sphenoidal surgery is currently the treatment of choice for Cushing's disease in children.

PATIENTS AND METHODS

The results obtained in 20 consecutive patients referred to the Pediatric Endocrinology Department of hôpital Saint-Vincent-de-Paul are reported.

RESULTS

A remission of Cushing's disease was observed in 12/16 (75%) patients in whom surgery was the first treatment. Among these 12 patients, three relapsed (25%) 21 to 80 months after surgery. Four patients were initially treated with steroid synthesis inhibitors: three of those patients were subsequently operated on and their disease remitted. Among the seven patients in whom surgery failed (primary failure or relapse), two were reoperated and also remitted. Taken together, 21 operations were performed and resulted in four immediate failures (19%), three relapses (14%) and 14 long-term remissions (67%, follow-up 40 +/- 35 months). None of the biological, radiological or operative criteria were predictive of the therapeutic results.

CONCLUSION

Our results illustrate the efficacy and limits of trans-sphenoidal surgery for Cushing's disease of children and emphasize the need for a very long follow-up of these patients. Treatment of patients in whom surgery has failed (initially or secondarily) is particularly difficult and requires a multidisciplinary approach.

Rejection of islets differing by a single antigen is dependent on donor MHC

To study the effect of expression of a single foreign antigen on the outcome of otherwise compatible mouse islet grafts, we have used transgenic mice expressing the human complement receptor 2 (CR2, CD21, C3d/EBV receptor) on their pancreatic beta-cells (RIP-CR2 mice). Donors were RIP-CR2 mice, typed at the major histocompatibility complex (MHC) as H-2(k), H-2(b), or H-2(bxk), and recipients were streptozotocin-treated nontransgenic B6 x CBA F1 mice (H-2(bxk)). H-2(b) or H-2(bxk) CR2-expressing islets were not rejected (mean survival time [MST] >100 days) but induced a peri-insulitis and an antibody response to CR2. In contrast, H-2(k) CR2-expressing islets were rejected in 80% of the cases with a MST of 65 +/- 23 days and were massively infiltrated by a destructive insulitis. In both cases, the infiltrate was mainly made of CD4+ cells, with few CD8+ cells. The isotype of IgG antibody response to CR2 was studied: recipients of H-2(k) grafts had a predominantly IgG1 response, while recipients of H-2(b) grafts had a balanced IgG2a and IgG1 response. To further evaluate the mechanism of differential rejection of the two types of grafts, recipients were immunized with CR2-expressing rat insulinoma cells before transplantation. Preimmunization with CR2 did not affect the outcome of H-2(b) grafts but greatly accelerated the rejection of H-2(k) grafts. These experiments indicate that expression of a single foreign antigen on beta-cells triggers an immune response leading to rejection or to peri-insulitis, depending on the MHC of donor islets.

[Primary hypothyroidism revealing pseudohypoparathyroidism without hypocalcemia and hyperphosphoremia]

BACKGROUND

Type la pseudohypoparathyroidism is due to a molecular defect causing Gs protein deficiency. It is responsible for multi-hormonal resistance and skeletal abnormalities. Parathyroid hormone resistance can be subtle so that the diagnosis can be difficult in patients with atypical manifestations.

CASE REPORT

A 10-year-old boy was first referred for growth retardation (height standard deviation score: -2.8). He had short metacarpals, and scaphocephaly. Laboratory findings revealed an elevation of plasma TSH (8,8 microU/mL) with normal thyroid hormone levels. The investigations ruled out common causes of compensated hypothyroidism. Despite normal blood calcium and phosphate levels, parathyroid hormone was elevated to 358 pg/mL (normal values: 10-60) without renal failure, suggestive of hormonal resistance. The diagnosis of pseudohypoparathyroidism type la was confirmed by a 50% reduction of Gs activity. Melanodermia, associated with an elevation of ACTH was suggestive of ACTH resistance without MSH resistance. Moreover, skeletal radiography showed a narrow lumbar canal.

CONCLUSION

Type la pseudoypoparathyroidism could be part of the etiological diagnosis of primary hypothyroidism, even in the absence of hypocalcemia and hyperphosphatemia. Similarly, skeletal abnormalities extend beyond the classical features of Albright's osteodystrophy.

Prediction and prevention of type 1 diabetes: what can be expected from genetics?

Current prediabetes screening relies mainly on immunologic markers. Genetic screening through HLA typing, which is used in families of affected patients, allows a stratification of risk levels according to the number and nature of alleles shared with the proband. Incomplete penetrance and the polygenic nature of susceptibility currently limit our ability to predict the disease with genetic markers. In addition, genetic factors can affect several aspects of the disease process, including insulin secretory capacity. This paper discusses the present and potential roles of genetic markers in prediabetes screening and briefly considers their use in the context of prevention trials.

[Association of mixed gonadal dysgenesis and non-classic 21-hydroxylase deficiency]

BACKGROUND

The rare association of mixed gonadal dysgenesis and non classical congenital hyperplasia by 21-hydroxylase deficiency poses the problem of their respective responsibility in the development of sexual ambiguity.

CASE REPORT

In a newborn with ambiguous genitalia, blood 17-OH progesterone was moderately elevated (3.9 to 14.1 ng/mL) leading to the diagnosis of non-classical 21 hydroxylase deficiency, Molecular studies later confirmed this diagnosis. However, the presence of a palpable gonad and the karyotype (45 X/46 XY mosaicism) indicated a mixed gonadal dysgenesis as the cause of sexual ambiguity. Histological examination revealed the presence of a testis and a streak gonad.

CONCLUSION

This observation emphasizes the need for a complete clinical and biological analysis in all newborns with sexual ambiguity.

Four families with loss of function mutations of the thyrotropin receptor

We observed four families with loss of function mutations of the TSH receptor gene. One patient had a homozygous Pro162 Ala substitution. The three other were compound heterozygotes: 1) Gln324-->Stop and Asp410 Asn2), Cys41 Ser and Phe525 Leu, 3) Cys390 Trp and Trp546-->Stop. In all patients, the plasma TSH concentration was increased, whereas T3 and T4 concentrations were normal. The TSH levels were normal in the heterozygous parents. These results confirmed the recessive character of TSH receptor defects. Expression of the various mutated receptors in transfected COS-7 cells demonstrated the impairment of their function. We studied the expression of the receptors on the cell surface by immunofluorescence, their ability to bind hormone, and their capacity to activate adenylate cyclase. Some mutations allowed us to identify sites that are especially important for receptor function. The substitution Cys390 Trp abolished high affinity hormone binding. Receptor mutated at Asp410 Asn bound the hormone normally, but failed to activate adenylate cyclase. This result underscores the role of this acidic extracellular residue, close to the first transmembrane segment, in signal transmission. The Phe525 Leu substitution also markedly impaired adenylate cyclase activation, underlining the importance of the second intracellular loop in receptor signaling.