Telemedicine maintains good glucose control in children with type 1 diabetes but is not time saving for healthcare professionals: KITES randomized study

AIMS

To evaluate glucose control non-inferiority and time benefits of telemedicine follow-up in children with type 1 diabetes (CwD).

METHODS

In a single-center 9-month-long randomized controlled study (clinicaltrials.gov NCT05484427), 50 children were randomized to either telemedicine group (TG) followed-up distantly by e-mail, or to face-to-face group (FFG) attending standard personal visits. The primary endpoint was non-inferiority of HbA1c at final visit (level of non-inferiority was set at 5 mmol/mol). The secondary endpoints were subcutaneous glucose monitoring parameters and time consumption from both study subjects' and the physicians' point of view.

RESULTS

Non-inferiority of HbA1c in the TG was proven (mean HbA1C 45.8 ± 7.3 [TG] vs. 50.0 ± 12.6 [FFG] mmol/mol, 6.3 vs. 6.7 % DCCT, p = 0.17; between groups HbA1C difference 95 % CI -10.2 to 1.9 mmol/mol). Telemedicine saved time for participants (mean visit duration [MVD] 50 [TG] vs. 247 min [FFG], p < 0.001). There were no other differences between groups neither in CGM parameters nor physician's time consumption (MVD 19 [TG] vs. 20 min [FFG], p = 0.58).

CONCLUSIONS

Nine-month telemedicine follow-up of the children with well-controlled T1D is not inferior to standard face-to-face visits. Telemedicine visits saved time for the participants but not for their diabetologists.

Genetic testing of children with familial tall stature: is it worth doing?

CONTEXT

Familial tall stature (FTS) is considered to be a benign variant of growth with a presumed polygenic etiology. However, monogenic disorders with possible associated pathological features could also be hidden under the FTS phenotype.

OBJECTIVES

To elucidate the genetic etiology in families with FTS and to describe their phenotype in detail.

DESIGN, SETTINGS AND PATIENTS

Children with FTS (height in both the child and his/her taller parent >2 SD) referred to the Endocrinology center of Motol University Hospital were enrolled to the study. Their DNA was examined cytogenetically and via next-generation sequencing panel of 786 genes associated with growth. The genetic results were evaluated by the American College of Molecular Genetics and Genomics guidelines. All of the participants underwent standard endocrinological examination followed by specialized anthropometric evaluation.

RESULTS

In total, 34 children (19 girls) with FTS were enrolled in the study. Their median height and their taller parent's height were 3.1 SD and 2.5 SD, respectively. The genetic cause of FTS was elucidated in 11/34 (32.4%) children (47, XXX and 47, XYY karyotypes, SHOX duplication, and causative variants in NSD1 [in 2], SUZ12 [in 2], FGFR3, CHD8, GPC3, and PPP2R5D genes). Ten children had absent syndromic sings and 24 had dysmorphic features.

CONCLUSION

Monogenic (and cytogenetic) etiology of FTS can be found among children with FTS. Genetic examination should be considered in all children with FTS regardless of the presence of dysmorphic features.

Introduction of continuous glucose monitoring (CGM) is a key factor in decreasing HbA1c in war refugee children with type 1 diabetes

AIMS

Our aim was to describe the changes in therapy and diabetes control in Ukrainian war refugee children with diabetes (CwD) during the first year of their stay in Czechia.

METHODS

A total of 124 CwD (62 male, 62 female) were enrolled into this observational study. Anthropometric, laboratory and diabetes management data were acquired at baseline and at 3 months intervals for 12 months. All CwD were offered a CGM device during their first visit. Generalized Estimating Equation models were fitted in order to estimate the dynamics of studied characteristics.

RESULTS

Median baseline HbA1c was 58 mmol/mol (IQR [48; 73]mmol/mol) (7.5 %, IQR[6.5;8.8]%). The HbA1c decreased significantly throughout the course of the study at a pace of - 2.2 mmol/mol (-0.2 %pt.) per visit (P = 0.01, CI[-3.2;-1.1]). The pace of the decrease in the average HbA1c was significantly higher in the group of CwD who received CGM in Czechia than in those who already had it from Ukraine by 2.9 mmol/mol (0.27 %pt.) per visit (P < 0.001, CI [-4.4; -1.3]).

CONCLUSIONS

The steepest decrease in HbA1c was observed in CwD with newly initiated CGM underlining its vital role in improving the glucose control of CwD regardless of their background.

Analysis of children with familial short stature: who should be indicated for genetic testing?

Familial short stature (FSS) describes vertically transmitted growth disorders. Traditionally, polygenic inheritance is presumed, but monogenic inheritance seems to occur more frequently than expected. Clinical predictors of monogenic FSS have not been elucidated. The aim of the study was to identify the monogenic etiology and its clinical predictors in FSS children. Of 747 patients treated with growth hormone (GH) in our center, 95 with FSS met the inclusion criteria (pretreatment height ≤-2 SD in child and his/her shorter parent); secondary short stature and Turner/Prader-Willi syndrome were excluded criteria. Genetic etiology was known in 11/95 children before the study, remaining 84 were examined by next-generation sequencing. The results were evaluated by American College of Medical Genetics and Genomics (ACMG) guidelines. Nonparametric tests evaluated differences between monogenic and non-monogenic FSS, an ROC curve estimated quantitative cutoffs for the predictors. Monogenic FSS was confirmed in 36/95 (38%) children. Of these, 29 (81%) carried a causative genetic variant affecting the growth plate, 4 (11%) a variant affecting GH-insulin-like growth factor 1 (IGF1) axis and 3 (8%) a variant in miscellaneous genes. Lower shorter parent's height (P = 0.015) and less delayed bone age (BA) before GH treatment (P = 0.026) predicted monogenic FSS. In children with BA delayed less than 0.4 years and with shorter parent's heights ≤-2.4 SD, monogenic FSS was revealed in 13/16 (81%) cases. To conclude, in FSS children treated with GH, a monogenic etiology is frequent, and gene variants affecting the growth plate are the most common. Shorter parent's height and BA are clinical predictors of monogenic FSS.

The Genetic Landscape of Children Born Small for Gestational Age with Persistent Short Stature

INTRODUCTION

Among children born small for gestational age, 10-15% fail to catch up and remain short (SGA-SS). The underlying mechanisms are mostly unknown. We aimed to decipher genetic aetiologies of SGA-SS within a large single-centre cohort.

METHODS

Out of 820 patients treated with growth hormone (GH), 256 were classified as SGA-SS (birth length and/or birth weight <-2 SD for gestational age and life-minimum height <-2.5 SD). Those with the DNA triplet available (child and both parents) were included in the study (176/256). Targeted testing (karyotype/FISH/MLPA/specific Sanger sequencing) was performed if a specific genetic disorder was clinically suggestive. All remaining patients underwent MS-MLPA to identify Silver-Russell syndrome, and those with unknown genetic aetiology were subsequently examined using whole-exome sequencing or targeted panel of 398 growth-related genes. Genetic variants were classified using ACMG guidelines.

RESULTS

The genetic aetiology was elucidated in 74/176 (42%) children. Of these, 12/74 (16%) had pathogenic or likely pathogenic (P/LP) gene variants affecting pituitary development (LHX4, OTX2, PROKR2, PTCH1, POU1F1), the GH-IGF-1 or IGF-2 axis (GHSR, IGFALS, IGF1R, STAT3, HMGA2), 2/74 (3%) the thyroid axis (TRHR, THRA), 17/74 (23%) the cartilaginous matrix (ACAN, various collagens, FLNB, MATN3), and 7/74 (9%) the paracrine chondrocyte regulation (FGFR3, FGFR2, NPR2). In 12/74 (16%), we revealed P/LP affecting fundamental intracellular/intranuclear processes (CDC42, KMT2D, LMNA, NSD1, PTPN11, SRCAP, SON, SOS1, SOX9, TLK2). SHOX deficiency was found in 7/74 (9%), Silver-Russell syndrome in 12/74 (16%) (11p15, UPD7), and miscellaneous chromosomal aberrations in 5/74 (7%) children.

CONCLUSIONS

The high diagnostic yield sheds a new light on the genetic landscape of SGA-SS, with a central role for the growth plate with substantial contributions from the GH-IGF-1 and thyroid axes and intracellular regulation and signalling.

First Use of Open-Source Automated Insulin Delivery AndroidAPS in Full Closed-Loop Scenario; Pancreas4ALL Randomized Pilot Study

Objective: We evaluated the safety and feasibility of open-source automated insulin delivery AndroidAPS in adolescents and young adults with type 1 diabetes (T1D) and compared its efficacy in three different scenarios: hybrid closed loop (HCL) with meal boluses, meal announcement only (MA), and full closed loop (FCL). Research Design and Methods: In an open-label, prospective, randomized crossover trial (clinicaltrials.gov NCT04835350), 16 adolescents with T1D (10 females) with mean age of 17 years (range 15-20), glycated hemoglobin 56 mmol/mol (range 43-75), and mean duration of diabetes 5.9 years (9-15) underwent three distinct 3-day periods of camp living, comparing the above-mentioned scenarios of AndroidAPS. We used modified and locked version of AndroidAPS 3.1.03, which was called Pancreas4ALL for study purposes. The order of MA and FCL periods was assigned randomly. The primary endpoints were feasibility and safety of the system represented by percentage of time of glucose control by the system and time in hypoglycemia below 3 mmol/L. Results: The glycemia was controlled by the system 95% time of the study and the proportion of time below 3 mmol/L did not exceed 1% over the whole study period (0.72%). The HCL scenario reached significantly higher percentage of time below 3 mmol/L (HCL 1.05% vs. MA 0.0% vs. FCL 0.0%; P = 0.05) compared to other scenarios. No difference was observed among the scenarios in the percentage of time between 3.9 and 10 mmol/L (HCL 83.3% vs. MA 79.85% vs. FCL 81.03%, P = 0.58) corresponding to mean glycemia (HCL 6.65 mmol/L vs. MA 7.34 mmol/L vs. FCL 7.05 mmol/L, P = 0.28). No difference was observed in the mean daily dose of insulin or in the daily carbohydrate intake. No serious adverse event occurred during the study period. Conclusions: Our pilot study showed that FCL might be a realistic mode of treatment for people with T1D.

Changes in the gut bacteriome upon gluten-free diet intervention do not mediate beta cell preservation

AIMS/HYPOTHESIS

We previously detected indications that beta cell function is protected by gluten-free diet (GFD) introduced shortly after the onset of childhood type 1 diabetes. The present aim was to assess whether GFD was associated with changes in the gut bacteriome composition and in its functional capacity, and whether such changes mediated the observed effects of GFD on beta cell function.

METHODS

Forty-five children (aged 10.2 ± 3.3 years) were recruited into a self-selected intervention trial primarily focused on determining the role of GFD on beta cell preservation ( ClinicalTrials.gov NCT02867436). Stool samples were collected prior to the dietary intervention and then at 3-month intervals. A total of 128 samples from the GFD group and 112 from the control group were analysed for bacteriome 16S rDNA community profiles, the bacteriome functional capacity was predicted using PICRUSt2 and actual gut metabolome profiles measured using NMR. Intestinal permeability was assessed using serum zonulin concentrations at 1, 6 and 12 months and lactulose/mannitol tests at the end of intervention. Dietary questionnaires were used to ensure that the dietary intervention did not result in differences in energy or nutrient intake.

RESULTS

The bacteriome community composition changed during the intervention with GFD: of abundant genera, a 3.3-fold decrease was noted for Bifidobacterium genus (adjusted p=1.4 × 10^-4 in a DESeq2 model, p=0.026 in generalised estimating equations model), whereas a 2.4-fold increase was observed in Roseburia (adjusted p=0.02 in DESeq2 model, p=0.002 in generalised estimating equations model). The within-sample (alpha) diversity did not change, and there was no statistically significant clustering of GFD samples in the ordination graphs of beta diversity. Neither of the genera changes upon GFD intervention showed any association with the pace of beta cell loss (p>0.50), but of the remaining taxa, several genera of Bacteroidaceae family yielded suggestive signals. The faecal metabolome profile ordination correlated with that of bacteriomes but did not associate with GFD or categories of beta cell preservation. There was no indication of changes in gut permeability.

CONCLUSIONS/INTERPRETATION

The bacteriome reacted to GFD, but the changes were unrelated to the pace of beta cell capacity loss. The previously observed moderately protective effect of GFD is therefore mediated through other pathways.

Isolated growth hormone deficiency in children with vertically transmitted short stature: What do the genes tell us?

INTRODUCTION

The growth hormone deficiency (GHD) diagnosis is controversial especially due to low specificity of growth hormone (GH) stimulation tests. It is therefore believed that children diagnosed with GHD form a heterogeneous group with growth disorder frequently independent on GH function. No study evaluating the complex etiology of growth failure in children with diagnosed GHD has been performed thus far.

AIMS

To discover genetic etiology of short stature in children with diagnosed GHD from families with short stature.

METHODS

Fifty-two children diagnosed with primary GHD and vertically transmitted short stature (height SDS in the child and his/her shorter parent <-2 SD) were included to our study. The GHD diagnosis was based on growth data suggestive of GHD, absence of substantial disproportionality (sitting height to total height ratio <-2 SD or >+2 SD), IGF-1 levels <0 for age and sex specific SD and peak GH concentration <10 ug/L in two stimulation tests. All children were examined using next-generation sequencing methods, and the genetic variants were subsequently evaluated by American College of Medical Genetics standards and guidelines.

RESULTS

The age of children at enrollment into the study was 11 years (median, IQR 9-14 years), their height prior to GH treatment was -3.0 SD (-3.6 to -2.8 SD), IGF-1 concentration -1.4 SD (-2.0 to -1.1 SD), and maximal stimulated GH 6.3 ug/L (4.8-7.6 ug/L). No child had multiple pituitary hormone deficiency or a midbrain region pathology. Causative variant in a gene that affects growth was discovered in 15/52 (29%) children. Of them, only 2 (13%) had a genetic variant affecting GH secretion or function (GHSR and OTX2). Interestingly, in 10 (67%) children we discovered a primary growth plate disorder (ACAN, COL1A2, COL11A1, COL2A1, EXT2, FGFR3, NF1, NPR2, PTPN11 [2x]), in one (7%) a genetic variant impairing IGF-1 action (IGFALS) and in two (12%) a variant in miscellaneous genes (SALL4, MBTPS2).

CONCLUSIONS

In children with vertically transmitted short stature, genetic results frequently did not correspond with the clinical diagnosis of GH deficiency. These results underline the doubtful reliability of methods standardly used to diagnose GH deficiency.

Low-Carbohydrate Diet among Children with Type 1 Diabetes: A Multi-Center Study

AIMS/HYPOTHESIS

The proportion of children with type 1 diabetes (T1D) who have experience with low-carbohydrate diet (LCD) is unknown. Our goal was to map the frequency of LCD among children with T1D and to describe their clinical and laboratory data.

METHODS

Caregivers of 1040 children with T1D from three centers were addressed with a structured questionnaire regarding the children's carbohydrate intake and experience with LCD (daily energy intake from carbohydrates below 26% of age-recommended values). The subjects currently on LCD were compared to a group of non-LCD respondents matched to age, T1D duration, sex, type and center of treatment.

RESULTS

A total of 624/1040 (60%) of the subjects completed the survey. A total of 242/624 (39%) subjects reported experience with voluntary carbohydrate restriction with 36/624 (5.8%) subjects currently following the LCD. The LCD group had similar HbA1c (45 vs. 49.5, p = 0.11), lower average glycemia (7.0 vs. 7.9, p = 0.02), higher time in range (74 vs. 67%, p = 0.02), lower time in hyperglycemia >10 mmol/L (17 vs. 20%, p = 0.04), tendency to more time in hypoglycemia <3.9 mmol/L(8 vs. 5%, p = 0.05) and lower systolic blood pressure percentile (43 vs. 74, p = 0.03). The groups did not differ in their lipid profile nor in current body height, weight or BMI. The LCD was mostly initiated by the parents or the subjects themselves and only 39% of the families consulted their decision with the diabetologist.

CONCLUSIONS/INTERPRETATION

Low carbohydrate diet is not scarce in children with T1D and is associated with modestly better disease control. At the same time, caution should be applied as it showed a tendency toward more frequent hypoglycemia.

Pre-school and school-aged children benefit from the switch from a sensor-augmented pump to an AndroidAPS hybrid closed loop: A retrospective analysis

OBJECTIVE

Data on closed loop systems in young children with type 1 diabetes (T1D) are limited. We tested the efficacy and safety of an open-source, do-it-yourself automated insulin delivery system AndroidAPS in preschool and school-aged children.

RESEARCH DESIGN AND METHODS

This retrospective study analyzed diabetes control in 18 preschool (3-7 years) and 18 school-aged children (8-14 years) with T1D who switched from a sensor-augmented pump (SAP) to AndroidAPS. We compared the CGM parameters and HbA1c levels 3 months before and 6 months after the initiation of AndroidAPS therapy and evaluated frequency of severe adverse events during AndroidAPS use, the most frequent reasons for its interruption, and the experience and psychosocial benefits of AndroidAPS use.

RESULTS

General glycemic control was significantly improved after the switch from SAP to AndroidAPS. Time in range (TIR) increased in both preschool (70.8%-78.6%, p = 0.004) and school-aged children (77.2%-82.9%, p < 0.001), whereas HbA1c levels decreased (preschool children 53.8-48.5 mmol/mol, p < 0.001; school-aged children 52.6-45.1 mmol/mol, p = 0.001). Time spent in range of 3.0-3.8 mmol/L increased slightly in school children (2.6%-3.8%, p = 0.040), but not in preschool children (3.0%-3.0%, p = 0.913). Time spent at <3 mmol/L remained unchanged in both preschool (0.95%-0.67%, p = 0.432) and school-aged children (0.8%-0.8%, p = 1.000). No episodes of severe hypoglycemia or DKA and significant improvement of quality of life were reported by AndroidAPS users.

CONCLUSIONS

AndroidAPS seems effective for T1D control both in preschool and school-age children but further validation by prospective studies is necessary.

Familial Short Stature-A Novel Phenotype of Growth Plate Collagenopathies

CONTEXT

Collagens are the most abundant proteins in the human body. In a growth plate, collagen types II, IX, X, and XI are present. Defects in collagen genes cause heterogeneous syndromic disorders frequently associated with short stature. Less is known about oligosymptomatic collagenopathies.

OBJECTIVE

This work aims to evaluate the frequency of collagenopathies in familial short stature (FSS) children and to describe their phenotype, including growth hormone (GH) treatment response.

METHODS

Eighty-seven FSS children (pretreatment height ≤ -2 SD both in the patient and his or her shorter parent) treated with GH were included in the study. Next-generation sequencing was performed to search for variants in the COL2A1, COL9A1, COL9A2, COL9A3, COL10A1, COL11A1, and COL11A2 genes. The results were evaluated using American College of Medical Genetics and Genomics guidelines. The GH treatment response of affected children was retrospectively evaluated.

RESULTS

A likely pathogenic variant in the collagen gene was found in 10 of 87 (11.5%) children. Detailed examination described mild asymmetry with shorter limbs and mild bone dysplasia signs in 2 of 10 and 4 of 10 affected children, respectively. Their growth velocity improved from a median of 5.3 cm/year to 8.7 cm/year after 1 year of treatment. Their height improved from a median of -3.1 SD to -2.6 SD and to -2.2 SD after 1 and 3 years of therapy, respectively. The final height reached by 4 of 10 children differed by -0.67 to +1.0 SD and -0.45 to +0.5 SD compared to their pretreatment height and their affected untreated parent's height, respectively.

CONCLUSION

Oligosymptomatic collagenopathies are a frequent cause of FSS. The short-term response to GH treatment is promising.

Stratifying the Genetic Aetiology in Children Born Small for Gestational Age With Persistent Short Stature (SGA-SS)

Background: Ten percent of children born small for gestational age with a birth weight and/or length of below -2 SD for their gestational age fail to catch-up and remain short during childhood (SGA-SS). The etiology of SGA-SS is heterogeneous: some children have specific phenotypic features that allow targeted genetic testing; in others, elucidating genetic or environmental background is more challenging. Aim: To decipher genetic etiologies among a large single-center cohort of SGA-SS children and to stratify them according to molecular mechanisms leading to pre- and postnatal growth failure. Patients/Methods: In our center 447 children (223 females) fulfilled the criteria of SGA-SS. Of these 182 families agreed to take part and offered the child’s and both parents’ DNA for genetic testing by a panel of 399 growth-related genes, or by Whole Exome Sequencing (WES). The results were processed by a bioinformatic pipeline and detected variants were filtered using variant analysis software. Pathogenic or likely pathogenic variants (according to ACMG standards and guidelines) were confirmed by Sanger sequencing. Results: The genetic etiology was elucidated in 73/182 (40%) children so far. We confirmed (likely) pathogenic gene variants affecting pituitary development and/or the GH-IGF-1 axis in 10/73 (14%) patients (PTCH1, HGMA2 [in two], OTX2, LHX4, GHSR, STAT3, IGFALS, IGF1R [in two]), abnormal components of cartilaginous matrix in 17/73 (23%) (ACAN [in two], FLNB [in three], FBLN5, COL11A1[in four], COL1A2, COL2A1[in five], MATN3), impaired paracrine regulation of chondrocytes in 4/73 (6%) (NPR2 [in three], FGFR3), SHOX gene defects in 12/73 (16%), gene variants affecting other components of intracellular regulation and signaling in 9/73 (12%) (CDC42, KMT2A, KMT2D, NSD1, SRCAP, PRG4, PTPN11, SON, LMNA), Silver-Russell syndrome (11p15 [in seven] or UPD7) in 11/73 (15%), and miscellaneous single-gene or chromosomal conditions (TRPS1, TRHR, RAI1, chromosomal microdeletions and/or translocations) in an additional ten (14%) children. Conclusions: In our study we showed that by using current genetic techniques we were able to elucidate the genetic cause in a significant number of patients born SGA-SS. The genetic etiology spectrum of SGA-SS reflects the complex system of growth regulation, with a significant role of growth plate genes that are causative in 33/73 (45%) cases clarified thus far. Acknowledgements: The study was co-funded by grants AZV NV18-07-00283 and GAUK 408120.

Familial Short Stature - a Novel Phenotype of Growth Plate Collagenopathies

Backround: Collagens are the most abundant proteins in the human body. In a growth plate, collagen types II, IX, X and XI are present. Defects in collagen genes cause heterogeneous syndromic disorders frequently associated with asymmetric short stature (e.g. Kniest dysplasia, spondyloepiphyseal dysplasia). Less is known about nonsyndromic collagenopathies - data about their frequency and subtle phenotypic signs are sparse, the information about their response to growth hormone (GH) treatment is lacking completely.

Aim: To evaluate the frequency of collagenopathies in familial short stature (FSS) children and to describe their phenotype, including growth hormone (GH) treatment response.

Methods: Out of 522 individuals treated in our center with GH from the indication of primary GH deficiency (GHD) or small for gestational age short stature (SGA-SS), 87 children with FSS fulfilled the inclusion criteria (pre-treatment height ≤-2 SD in both patient/their shorter parent, signed written informed consent) and were enrolled to the study. Next-generation sequencing was performed to search for variants in COL2A1, COL9A1, COL9A2, COL9A3, COL10A1, COL11A1 and COL11A2 genes. The results were evaluated using ACMG guidelines. The phenotype of children with (likely) pathogenic variants was described including the short-term GH treatment response (growth velocity and body-height SDS increase over three years of treatment). For statistical evaluation, parametric tests were used, p-values <0.05 were considered significant.

Results: A (likely) pathogenic variant in one of the collagen genes was found in 10/87 (11.5%) children. Their age was 12.5 years (median, range 6-17 years), their pre-treatment height was -3.1 SD (-2.4 to -4.3 SD). Their birth length (median -2.8 SD; range -0.7 to -4.1 SD) was more severely affected than birth weight (median -2.1 SD; range -1.0 to -2.7 SD). Eight children were treated with GH from SGA-SS indication, the remaining 2 were classified as mild GHD (maximal stimulated GH concentration 8.0 and 9.7 ug/l, normal brain MRI and examination of other pituitary hormones). Detailed anthropometric examination described mild asymmetry with shorter limbs and mild bone dysplasia signs (scoliosis, more pronounced lumbar lordosis, genua valga, limited elbow extension) in 2/10 and 4/10 affected children, respectively. Growth velocity improved from a median of 5.3 cm/year to 8.7 cm/year after one year of treatment (p<0.001, paired-sample T-test), height improved from a median of -3.1 SD to -2.2 SD after three years of therapy (p=0.001, ANOVA repeated measures analysis of variants).

Conclusion: Nonsyndromic collagenopathies are a frequent cause of FSS. The short-term response to GH treatment is promising.

Supported by the Ministry of Health, Czech Republic, grant number NV18- 07-00283 and by the research project of the Grant Agency of Charles University of Prague, GAUK 976718.

Gluten-free diet in children with recent-onset type 1 diabetes: A 12-month intervention trial

AIM

To test whether a gluten-free diet (GFD) is associated with the deceleration of the decline in beta-cell capacity in non-coeliac children with recently diagnosed type 1 diabetes.

METHODS

Forty-five children (aged 10.2 ± 3.3 years) were recruited into a self-selected intervention trial: 26 started with a GFD within a median of 38 days postonset, whereas 19 remained on a standard diet. The main outcomes were the decline in C-peptide area under the curve (AUC) in mixed-meal tolerance tests (MMTTs) at 6 and 12 months relative to 1 month after diabetes onset and the difference in insulin dose, insulin dose-adjusted A1c (IDAA1c) and HbA1c assessed every 3 months. The adherence to the GFD was verified by immunoreactive gluten in the stool and by food questionnaires at every visit. Quality of life (QoL) questionnaires were administered to the participants at the end of the intervention at 12 months. The data were analysed as per protocol (in 39 subjects who duly completed the whole follow-up: 20 in the GFD group, 19 in the control group) by linear and longitudinal regression models adjusted for sex, age and baseline variables.

RESULTS

At 12 months, the difference in C-peptide AUC between subjects in the GFD group and controls was 205 pmol/L (95% CI -223 to 633; P = 0.34) in a model adjusted for age, sex and body weight, and for baseline insulin dose, MMTT C-peptide AUC and HbA1c assessed at 1 month after diagnosis. In a longitudinal analysis of all three time points adjusted for age, sex and body weight, C-peptide declined more slowly in the GFD group than in controls, with the difference in trends being 409 pmol/L/year (P = 0.04). The GFD group had a marginally lower insulin dose (by 0.15 U/kg/day; P = 0.07), a lower IDAA1c (by 1.37; P = 0.01) and a lower mean HbA1c (by 0.7% [7.8 mmol/mol]; P = 0.02) than those of the controls at 12 months. There was no appreciable difference between the groups in daily carbohydrate intake (P = 0.49) or in the QoL reported by the patients (P = 0.70) and their parents/caregivers (P = 0.59).

CONCLUSIONS

A GFD maintained over the first year after type 1 diabetes diagnosis was associated with better HbA1c and a prolonged partial remission period. There was a hint of slower C-peptide decline but the association was not strong enough to make definite conclusions.

Changes in innate and adaptive immunity over the first year after the onset of type 1 diabetes

AIMS

The development of the immune phenotype in patients with type 1 diabetes (T1D) during the first year following disease onset remains poorly described, and studies analysing the longitudinal development of a complex set of immunological and metabolic parameters are missing. Thus, we aim to provide such complex view in a cohort of 38 children with new onset T1D who were prospectively followed for 1 year.

METHODS

All subjects were tested for a set of immunological parameters (complete blood count; serum immunoglobulins; and T, B and dendritic cells), HbA1c and daily insulin dose at baseline and at 6 and 12 months after T1D diagnosis. A mixed meal tolerance test was administered to each of the subjects 12 months after diagnosis, and the C-peptide area under the curve (AUC) was noted and was then tested for association with all immunological parameters.

RESULTS

A gradual decrease in leukocytes (adjusted p = 0.0012) was reflected in a significant decrease in neutrophils (adjusted p = 0.0061) over the post-onset period, whereas Tregs (adjusted p = 0.0205) and originally low pDCs (adjusted p < 0.0001) increased. The expression of the receptor for BAFF (BAFFR) on B lymphocytes (adjusted p = 0.0127) markedly increased after onset. No immunological parameters were associated with C-peptide AUC; however, we observed a linear increase in C-peptide AUC with the age of the patients (p < 0.0001).

CONCLUSIONS

Our study documents substantial changes in the innate and adaptive immune system over the first year after disease diagnosis but shows no association between immunological parameters and residual beta-cell activity. The age of patients remains the best predictor of C-peptide AUC, whereas the role of the immune system remains unresolved.

NPR2 Variants Are Frequent among Children with Familiar Short Stature and Respond Well to Growth Hormone Therapy

CONTEXT

The C-type natriuretic peptide receptor encoded by the NPR2 gene is a paracrine regulator of the growth plate; heterozygous NPR2 variants cause short stature with possible presence of different signs of bone dysplasia. To date, the effect of growth hormone (GH) treatment has been described in a few individuals with NPR2 gene variants with inconsistent results.

OBJECTIVES

To identify NPR2 gene variants among children with familial short stature (FSS) and to describe their phenotype, including GH treatment response.

DESIGN, SETTINGS AND PATIENTS

Out of 747 patients with short stature treated with GH in a single center, 87 with FSS met the inclusion criteria (pretreatment height ≤ -2 standard deviation in both the patient and the shorter parent, unknown genetic etiology). Next-generation sequencing methods were performed to search for NPR2 gene variants. The results were evaluated using the American College of Medical Genetics and Genomics guidelines. The GH treatment response (growth velocity improvement and height standard deviation score development over the first 5 years of treatment) was evaluated.

RESULTS

In 5/87 children (5.7%), a (likely) pathogenic variant in the NPR2 gene was identified (p.Ile558Thr [in 2], p.Arg205*, p.Arg557His, p.Ser603Thr). Two children had disproportionate short-limbed short stature, 1 a dysplastic 5th finger phalanx. The growth velocity in the first year of GH treatment accelerated by 3.6 to 4.2 cm/year; the height improved by 1.2 to 1.8 SD over 5 years of treatment.

CONCLUSIONS

NPR2 gene variants cause FSS in a significant proportion of children. Their GH treatment response is promising. Studies including final height data are necessary to assess the long-term efficacy of this therapy.

Primary School Performance of Girls with Turner Syndrome: A Transcultural Assessment

OBJECTIVES

We analyzed primary school performance of girls with Turner syndrome (TS) in two distinct countries to ascertain if the cognitive phenotype of TS causes selective learning difficulties.

METHODS

The cohort comprised of 44 Czech and 50 Egyptian girls with TS who attended public schools. School reports from grades 1 to 9 were obtained retrospectively from Czech participants with TS. Only recent school reports were obtained from Egyptian participants. Two controls per participant were requested - biological sisters and/or female classmates. The results were converted into a 5-point scale (1-excellent; 5-unsatisfactory).

RESULTS

Analysis of longitudinal Czech data displayed a strong time component in both subjects and controls. Showing better points in lower grades with its gradual worsening as the education complexity increased. In contrast, there was a strong statistically significant difference between groups in Mathematics (p=0.0041, p=0.0205 after Bonferroni correction) and this difference increased over time. The points for Mathematics did not differ in grades 1+2 (0.05 difference in mean grade between the two groups), however, they differed by 0.28 in grades 6+7 and by 0.32 in grades 8+9. While slightly different in character (cross-sectional vs. longitudinal), the Egyptian cohort data confirmed our findings, showing no difference in general school performance but having similar trends in Mathematics (grades 1+2: 0.11, grades 6+7: 0.54, grades 8+9: 0.68; p=0.0058, p=0.029 after Bonferroni correction).

CONCLUSION

Excluding results in Mathematics, which showed pronounced worsening in relation to age in comparison with unaffected controls, girls with TS performed similarly to their controls.

Screening of monogenic autoimmune diabetes among children with type 1 diabetes and multiple autoimmune diseases: is it worth doing?

Background Paediatric type 1 diabetes (T1D) and rare syndromes of monogenic multi-organ autoimmunity share basic features such as full insulin dependency and the presence of circulating beta-cell autoantibodies. However, the aetiopathogenesis, natural course and treatment of these conditions differ; therefore, monogenic multi-organ autoimmunity requires early recognition. We aimed to search for these monogenic conditions among a large cohort of children with T1D. Methods Of 519 children with T1D followed-up in a single centre, 18 had multiple additional autoimmune conditions - either autoimmune thyroid disease (AITD) and coeliac disease (CD) or at least one additional organ-specific autoimmune condition in addition to AITD or CD. These 18 children were tested by direct Sanger sequencing (four patients with a suggestive phenotype of immune dysregulation, polyendocrinopathy, enteropathy, X-linked [IPEX] or signal transducer and activator of transcription 3 [STAT3]- and cytotoxic T-lymphocyte protein 4 [CTLA4]-associated syndromes) or by whole-exome sequencing (WES) focused on autoimmune regulator (AIRE), forkhead box protein 3 (FOXP3), CTLA4, STAT3, signal transducer and activator of transcription 1 (STAT1), lipopolysaccharide-responsive and beige-like anchor protein (LRBA) and interleukin-2 receptor subunit α (IL2RA) genes. In addition, we assessed their T1D genetic risk score (T1D-GRS). Results We identified novel variants in FOXP3, STAT3 and CTLA4 in four cases. All patients had a severe phenotype suggestive of a single gene defect. No variants were identified in the remaining 14 patients. T1D-GRS varied among the entire cohort; four patients had scores below the 25th centile including two genetically confirmed cases. Conclusions A monogenic cause of autoimmune diabetes was confirmed only in four patients. Genetic screening for monogenic autoimmunity in children with a milder phenotype and a combination of AITD and CD is unlikely to identify a monogenic cause. In addition, the T1D-GRS varied among individual T1D patients.

High Prevalence of Growth Plate Gene Variants in Children With Familial Short Stature Treated With GH

CONTEXT

Familial short stature (FSS) is a term describing a growth disorder that is vertically transmitted. Milder forms may result from the combined effect of multiple genes; more severe short stature is suggestive of a monogenic condition. The etiology of most FSS cases has not been thoroughly elucidated to date.

OBJECTIVES

To identify the genetic etiology of severe FSS in children treated with GH because of the diagnosis of small for gestational age or GH deficiency (SGA/GHD).

DESIGN, SETTINGS, AND PATIENTS

Of 736 children treated with GH because of GHD/SGA, 33 with severe FSS (life-minimum height -2.5 SD or less in both the patient and shorter parent) were included in the study. The genetic etiology was known in 5 of 33 children prior to the study [ACAN (in 2], NF1, PTPN11, and SOS1). In the remaining 28 of 33, whole-exome sequencing was performed. The results were evaluated using American College of Medical Genetics and Genomics standards and guidelines.

RESULTS

In 30 of 33 children (90%), we found at least one variant with potential clinical significance in genes known to affect growth. A genetic cause was elucidated in 17 of 33 (52%). Of these children, variants in growth plate-related genes were found in 9 of 17 [COL2A1, COL11A1, and ACAN (all in 2), FLNB, FGFR3, and IGF1R], and IGF-associated proteins were affected in 2 of 17 (IGFALS and HMGA2). In the remaining 6 of 17, the discovered genetic mechanisms were miscellaneous (TRHR, MBTPS2, GHSR, NF1, PTPN11, and SOS1).

CONCLUSIONS

Single-gene variants are frequent among families with severe FSS, with variants affecting the growth plate being the most prevalent.

Short Stature in a Boy with Multiple Early-Onset Autoimmune Conditions due to a STAT3 Activating Mutation: Could Intracellular Growth Hormone Signalling Be Compromised?

BACKGROUND

Germline STAT3 gain-of-function (GOF) mutations cause multiple endocrine and haematologic autoimmune disorders, lymphoproliferation, and growth impairment. As the JAK-STAT pathway is known to transduce the growth hormone (GH) signalling, and STAT3 interacts with STAT5 in growth regulation, we hypothesised that short stature in STAT3 GOF mutations results mostly from GH insensitivity via involving activation of STAT5.

CASE REPORT

A boy with a novel STAT3 c.2144C>T (p.Pro715Leu) mutation presented with short stature (-2.60 SD at 5.5 years). He developed diabetes mellitus at 11 months, generalised lympho-proliferation, autoimmune thyroid disease, and immune bicytopenia in the subsequent years. At 5.5 years, his insulin-like growth factor-1 (IGF-I) was 37 µg/L (-2.22 SD) but stimulated GH was 27.7 µg/L. Both a standard IGF-I generation test (GH 0.033 mg/kg/day sc; 4 days) and a high-dose prolonged IGF-I generation test (GH 0.067 mg/kg/day sc; 14 days) failed to significantly increase IGF-I levels (37-46 and 72-87 µg/L, respectively). The boy underwent haematopoietic stem cell transplantation at 6 years due to severe neutropenia and massive lymphoproliferation, but unfortunately deceased 42 days after transplantation from reactivated generalised adenoviral infection.

CONCLUSIONS

Our findings confirm the effect of STAT3 GOF mutation on the downstream activation of STAT5 resulting in partial GH insensitivity. 
.

For Debate: Should Bariatric Surgery be Performed in Children and Adolescents with Hypothalamic Obesity?

Hypothalamic dysfunction leading to severe obesity is a serious long-term consequence of paediatric craniopharyngioma. It compromises quality of life, leads to long-term metabolic hazards, and may shorten life expectancy. Therefore, a proactive approach is required. Conventional treatment of hypothalamic obesity is difficult and hardly successful. Experience with bariatric surgery is limited, especially in younger patients. Two retrospective studies recently reported on classic bariatric surgery in a small series of individuals after craniopharyngioma. Of these, one included nine paediatric patients who underwent laparoscopic adjustable gastric banding (LAGB), sleeve gastrectomy (SG), Roux-en-Y gastric bypass (RYGB) or biliopancreatic diversion (BPD). The immediate effects were promising: The mean weight loss was 20.9 kilograms at 6 months and 15.1 kilograms at 12 months. A duodenal-jejunal bypass sleeve (DBJS; EndoBarrier) is a mini-invasive, endoscopically placed and fully reversible bariatric procedure. We reported a boy diagnosed with craniopharyngioma at 10 years old who underwent surgery and radiotherapy. His body weight increased to 139 kilograms and body mass index (BMI) to 46.1 kg/m2 (+4.0 SD) within the subsequent 4.5 years. Fifteen months after DJBS placement, he lost 32.8 kilograms, and his BMI dropped to 32.7 kg/m2 (+2.9 SD). Thus, DJBS proved to be a promising procedure in the treatment of hypothalamic obesity. We suggest performing it in children and adolescents with hypothalamic obesity to prevent or attenuate its devastating long-term sequelae.

Muscle functions and bone strength are impaired in adolescents with type 1 diabetes

BACKGROUND

Sarcopenia and osteoporosis are among the late complications of type 1 diabetes (T1D) in adults. Whether and to what extent musculoskeletal impairment is present in childhood and adolescence has yet to be determined. The aim of this study was to assess volumetric bone mineral density (BMD) and dynamic muscle function in adolescents with T1D and to assess the clinical and biochemical predictors of their musculoskeletal system.

METHODS

Ninety-five children and adolescents (59 boys and 36 girls, mean age 16.2±1.2years) with T1D were included in this cross-sectional study. Study participants were divided into two groups according to the duration of the disease (<6years and >9years, respectively). Volumetric BMD of the non-dominant tibia was assessed using peripheral quantitative computed tomography (pQCT). Dynamic muscle function was evaluated using jumping mechanography. Gender- and height-specific Z-scores were calculated using published reference data. HbA1c was evaluated retrospectively as an average over the past 5years.

RESULTS

Relative muscle power (P_max/mass) and force (F_max/body weight) were significantly decreased in T1D subjects (mean Z-scores -0.4±1.0; p<0.001, and -0.3±1.1; p<0.01, respectively). The duration of T1D negatively affected P_max/mass (p<0.01) but not F_max/body weight (p=0.54). Patients with T1D had also decreased trabecular BMD, the Strength-Strain Index and cortical thickness (mean Z-scores -0.8±1.3; -0.5±0.8 and -1.1±0.8, respectively, p<0.001 for all) whereas cortical BMD was increased when compared to controls (Z-score 1.2±0.90, p<0.001). No association was observed between the HbA1c and 25-hydroxyvitamin D levels and bone or muscle parameters.

CONCLUSION

T1D influences the musculoskeletal system in adolescence. Decreased muscle function could contribute to the osteoporosis reported in adult diabetic patients.

Glucokinase Gene May Be a More Suitable Target Than the Insulin Gene for Detection of β Cell Death

Detection and quantification of unmethylated circulating insulin (INS) DNA presumably released from β cells has been previously used for assessing their destruction. As the targets within the INS gene suffer from suboptimal specificity, we sought to improve the assay parameters by using the glucokinase gene (GCK) tissue-specific pancreatic promoter. The amount of methylated and unmethylated GCK DNA was measured using a droplet polymerase chain reaction assay and compared with the previously published INS-targeted assay. The method was tested using synthetic target sequences and DNA from pancreatic islets, blood, brain, kidney, large intestine, liver, lung, small intestine, and stomach. Circulating serum DNA was obtained from children with recent-onset type 1 diabetes (T1D) (n = 25), autoantibody-positive first-degree relatives of T1D patients (n = 14), and healthy controls (n = 20). The unmethylated GCK DNA was found to be more islet specific than unmethylated INS DNA. The proportion of the unmethylated GCK DNA was lower than INS in all tested extrapancreatic tissues, except kidney. Although the amounts of methylated DNA measured by the two assays were similar, the INS assay detected considerably more unmethylated DNA. Whereas none of the assays showed significant increase in the amount of unmethylated DNA, the ratio of unmethylated/methylated GCK DNA was borderline significantly increased in autoantibody-positive relatives compared with T1D patients (P = 0.04) and controls (P = 0.06). Targeting the assay into the GCK gene improved analytical parameters of the assay. As the amount of unmethylated target DNA in properly treated samples is very low, the clinical utility of this method remains to be evaluated.

Alteration of B cell subsets and the receptor for B cell activating factor (BAFF) in paediatric patients with type 1 diabetes

BACKGROUND

Lately, mounting evidence has shown that B cells play an important role in the pathogenesis of type 1 diabetes (T1D). Here, we present alterations in B cell subsets including BAFF receptor (BAFFR) expression in cohorts of patients with type 1 diabetes (T1D) and their relatives.

PATIENTS AND METHODS

B cells were studied in 438 patients with T1D (158 at disease onset and 280 with long-term disease), 136 first-degree relatives and 53 healthy controls. The B cell panel included transitional, naïve, MZ-like, switched memory B cells and plasmablasts. We also measured serum BAFF levels as well as BAFFR expression on both B and T cells. Moreover, the effect of BAFF on T and B lymphocytes was analysed in vitro.

RESULTS

We observed a significant decrease in the proportion of transitional B cells in the patients with T1D, accompanied by an increased proportion of plasmablasts, especially in recent-onset patients and their relatives. While the BAFF serum levels did not differ in the patients with T1D, BAFFR-expressing B and especially T cell numbers were reduced in the T1D cohort, with the exception of patients with recent-onset disease who exhibited a significant increase in the number of BAFFR-expressing T cells. T cell activation and B cell proliferation were more pronounced after activation with BAFF in the T1D cohort compared to controls.

CONCLUSION

The B cell panel in patients with T1D is characterized by significantly reduced populations of B cells in their early stages of development with a shift towards plasma cells. The dynamics of BAFFR-expressing B and T cells and the more pronounced responsiveness of the T1D T cells to BAFF point to the role of BAFF and T and B cell cooperation in the development of T1D.

Substantial proportion of MODY among multiplex families participating in a Type 1 diabetes prediction programme

AIMS

Patients with maturity-onset diabetes of the young (MODY) might be over-represented in families with histories of Type 1 diabetes. Our aim was to re-evaluate families participating in the Czech T1D Prediction Programme (PREDIA.CZ) with at least two members affected with diabetes to assess the proportion of MODY among these families and determine its most significant clinical predictors.

METHODS

Of the 557 families followed up by the PREDIA.CZ, 53 (9.5%) had two or more family members with diabetes. One proband with diabetes from these families was chosen for direct sequencing of the GCK, HNF1A, HNF4A and INS genes. Non-parametric tests and a linear logistic regression model were used to evaluate differences between MODY and non-MODY families.

RESULTS

MODY was genetically diagnosed in 24 of the 53 families with multiple occurrences of diabetes (45%). Mutations were detected most frequently in GCK (58%), followed by HNF1A (38%) and INS (4%). MODY families were more likely to have a parent with diabetes and had a higher proportion of females with diabetes than non-MODY families. Higher age (P < 0.001), a lower level of HbA_1c (P < 0.001) at clinical onset and at least two generations affected by diabetes were the variables most predictive for probands of MODY families already presenting with diabetes.

CONCLUSIONS

A prediction programme for Type 1 diabetes would provide a useful new source of patients with MODY most likely to benefit from an accurate diagnosis. This identification has implications for patient treatment and disease prognosis.

T regulatory lymphocytes in type 1 diabetes: Impaired CD25 expression and IL-2 induced STAT5 phosphorylation in pediatric patients

T regulatory cells (Tregs) are essential for maintaining tolerance and preventing autoimmune diseases, such as type 1 diabetes (T1D). In our study, we investigated CD25 + FoxP3 + Tregs and thymic FoxP3 + Helios + Tregs in large cohorts of children with T1D at onset and with long-term T1D, and further in their relatives and healthy controls. We observed significantly decreased numbers of CD25 + FoxP3 + Tregs, but not FoxP3 + Helios + Tregs, in long-term patients compared with the control group and T1D onset. Furthermore, long-term T1D patients exhibited highly significant decrease of CD25 expression on both CD25 + FoxP3 + Tregs and FoxP3 + Helios + Tregs, independently on age or the duration of diabetes. A similar reduction of CD25 expression was also found in T1D relatives, more significant in those with positive autoantibodies. Low CD25 expression was associated with impaired signal transducer and activator of transcription 5 (STAT5) phosphorylation after IL-2 exposure. Our results show that the frequency of Tregs is altered in a large cohort of long-term T1D patients, a profound decrease in CD25 expression and altered IL-2 signaling are typical features of Tregs populations in long-term diabetic patients and their relatives.

Healthy first-degree relatives of patients with type 1 diabetes exhibit significant differences in basal gene expression pattern of immunocompetent cells compared to controls: expression pattern as predeterminant of autoimmune diabetes

Expression features of genetic landscape which predispose an individual to the type 1 diabetes are poorly understood. We addressed this question by comparing gene expression profile of freshly isolated peripheral blood mononuclear cells isolated from either patients with type 1 diabetes (T1D), or their first-degree relatives or healthy controls. Our aim was to establish whether a distinct type of 'prodiabetogenic' gene expression pattern in the group of relatives of patients with T1D could be identified. Whole-genome expression profile of nine patients with T1D, their ten first-degree relatives and ten healthy controls was analysed using the human high-density expression microarray chip. Functional aspects of candidate genes were assessed using the MetaCore software. The highest number of differentially expressed genes (547) was found between the autoantibody-negative healthy relatives and the healthy controls. Some of them represent genes critically involved in the regulation of innate immune responses such as TLR signalling and CCR3 signalling in eosinophiles, humoral immune reactions such as BCR pathway, costimulation and cytokine responses mediated by CD137, CD40 and CD28 signalling and IL-1 proinflammatory pathway. Our data demonstrate that expression profile of healthy relatives of patients with T1D is clearly distinct from the pattern found in the healthy controls. That especially concerns differential activation status of genes and signalling pathways involved in proinflammatory processes and those of innate immunity and humoral reactivity. Thus, we posit that the study of the healthy relative's gene expression pattern is instrumental for the identification of novel markers associated with the development of diabetes.

Muscle function in Turner syndrome: normal force but decreased power

OBJECTIVE

Although hypogonadism and SHOX gene haploinsufficiency likely cause the decreased bone mineral density and increased fracture rate associated with Turner syndrome (TS), the exact mechanism remains unclear. We tested the hypothesis that muscle dysfunction in patients with TS contributes to increased fracture risk. The secondary aim was to determine whether menarche, hormone therapy duration, positive fracture history and genotype influence muscle function parameters in patients with TS.

DESIGN

A cross-sectional study was conducted in a single university hospital referral centre between March 2012 and October 2013.

PATIENTS

Sixty patients with TS (mean age of 13·7 ± 4·5 years) were compared to the control group of 432 healthy girls.

MEASUREMENTS

A Leonardo Mechanograph(®) Ground Reaction Force Platform was used to assess muscle force (Fmax ) by the multiple one-legged hopping test and muscle power (Pmax ) by the single two-legged jump test.

RESULTS

While the Fmax was normal (mean weight-specific Z-score of 0·11 ± 0·77, P = 0·27), the Pmax was decreased in patients with TS (Z-score of -0·93 ± 1·5, P < 0·001) compared with healthy controls. The muscle function parameters were not significantly influenced by menarcheal stage, hormone therapy duration, fracture history or genotype (linear regression adjusted for age, weight and height; P > 0·05 for all).

CONCLUSION

Fmax , a principal determinant of bone strength, is normal in patients with TS. Previously described changes in bone quality and structure in TS are thus not likely related to inadequate mechanical loading but rather represent a primary bone deficit. A decreased Pmax indicates impaired muscle coordination in patients with TS.

Treated Autoimmune Thyroid Disease Is Associated with a Decreased Quality of Life among Young Persons with Type 1 Diabetes

Type 1 diabetes (T1D) in children and adolescents is relatively often accompanied by other immunopathological diseases, autoimmune thyroid disease (AITD) or celiac disease (CD). Our aim was to assess whether these conditions are associated with changes in the health-related quality of life (HRQOL) in pediatric patients with T1D. In a cross-sectional study we identified eligible 332 patients with T1D aged 8-18 years, of whom 248 (75%) together with their parents responded to the PedsQL Generic and Diabetes Modules. Compared to 143 patients without thyroid autoantibodies, 40 patients with a thyroxine-treated AITD scored lower in the overall generic HRQOL (P = 0.014), as well as in the overall diabetes-specific HRQOL (P = 0.013). After adjustment for age, gender, duration of diabetes, type of diabetes treatment, and diabetes control, this association remained statistically significant for the generic HRQOL (P = 0.023). Celiac disease was not associated with a change in the generic or diabetes-specific HRQOL (P = 0.07  and  P = 0.63, resp.). Parental scores showed no association with AITD or celiac disease, except a marginally significant decrease in the overall generic HRQOL (P = 0.039) in the T1D + AITD compared to T1D group. Our study indicates that, in pediatric patients with T1D, concomitant thyroxine-treated AITD is associated with lower quality of life.

Human NR5A1/SF-1 mutations show decreased activity on BDNF (brain-derived neurotrophic factor), an important regulator of energy balance: testing impact of novel SF-1 mutations beyond steroidogenesis

Context

Human NR5A1/SF-1 mutations cause 46,XY disorder of sex development (DSD) with broad phenotypic variability, and rarely cause adrenal insufficiency although SF-1 is an important transcription factor for many genes involved in steroidogenesis. In addition, the Sf-1 knockout mouse develops obesity with age. Obesity might be mediated through Sf-1 regulating activity of brain-derived neurotrophic factor (BDNF), an important regulator of energy balance in the ventromedial hypothalamus.

Objective

To characterize novel SF-1 gene variants in 4 families, clinical, genetic and functional studies were performed with respect to steroidogenesis and energy balance.

Patients

5 patients with 46,XY DSD were found to harbor NR5A1/SF-1 mutations including 2 novel variations. One patient harboring a novel mutation also suffered from adrenal insufficiency.

Methods

SF-1 mutations were studied in cell systems (HEK293, JEG3) for impact on transcription of genes involved in steroidogenesis (CYP11A1, CYP17A1, HSD3B2) and in energy balance (BDNF). BDNF regulation by SF-1 was studied by promoter assays (JEG3).

Results

Two novel NR5A1/SF-1 mutations (Glu7Stop, His408Profs*159) were confirmed. Glu7Stop is the 4^th reported SF-1 mutation causing DSD and adrenal insufficiency. In vitro studies revealed that transcription of the BDNF gene is regulated by SF-1, and that mutant SF-1 decreased BDNF promoter activation (similar to steroid enzyme promoters). However, clinical data from 16 subjects carrying SF-1 mutations showed normal birth weight and BMI.

Conclusions

Glu7Stop and His408Profs*159 are novel SF-1 mutations identified in patients with 46,XY DSD and adrenal insufficiency (Glu7Stop). In vitro, SF-1 mutations affect not only steroidogenesis but also transcription of BDNF which is involved in energy balance. However, in contrast to mice, consequences on weight were not found in humans with SF-1 mutations.

Decreased dendritic cell numbers but increased TLR9-mediated interferon-alpha production in first degree relatives of type 1 diabetes patients

OBJECTIVE

Dendritic cells (DCs) play an important role in pathogenesis of autoimmunity, including type 1 diabetes (T1D). In this study, we investigated DC subpopulations and their responses to TLR stimulation in T1D patients and their relatives.

METHODS

We analyzed the frequency of myeloid (mDCs) and plasmacytoid DCs (pDCs) in 97 T1D patients (69 onset, 28 long-term), 67 first-degree relatives, and 64 controls. We additionally tested the IFN-alpha production by pDCs upon stimulation with TLR 7, 8 and 9 agonists.

RESULTS

A lower number of mDCs and pDCs were found in T1D patients and their relatives. Of all the tested TLR ligands, only stimulation with CpG 2216 induced IFN-alpha production that was the highest in T1D relatives, except of autoantibody-negative relatives bearing the protective haplotypes.

CONCLUSION

Our data demonstrate disturbances in DC number and function expressed most significantly in T1D relatives and point to a potential role of TLR9-induced IFN-alpha production in T1D development.

The dynamic changes of zinc transporter 8 autoantibodies in Czech children from the onset of Type 1 diabetes mellitus

AIMS

The prevalence of autoantibodies to zinc transporter 8 (ZnT8) in Czech children at the onset of Type 1 diabetes mellitus and dynamic changes in ZnT8 autoantibody levels during disease progression were studied. The value of ZnT8 autoantibody measurements in diagnosis of Type 1 diabetes was assessed.

METHODS

Serum samples from 227 children with newly diagnosed Type 1 diabetes and from 101 control children without diabetes were analysed in a retrospective cross-sectional study. One hundred and seventy-one samples from 116 of the patients with diabetes were analysed in a follow-up study at (median) intervals of 1, 3, 5 and 10 years after onset of Type 1 diabetes. ZnT8 autoantibodies were measured using a bridging enzyme-linked immunosorbent assay, while antibodies to glutamic acid decarboxylase, insulinoma antigen 2 and insulin were measured by radioimmunoassays.

RESULTS

ZnT8 autoantibodies were detected in 163/227 (72%) of children at Type 1 diabetes onset and in 1/101 (1%) of the control subjects. Sixteen out of 227 (7%) patients with Type 1 diabetes were antibody negative based on three antibodies (glutamic acid decarboxylase, insulinoma antigen 2 and insulin). This false-negative rate was reduced to 10/227 (4.4%) (P < 0.05) after inclusion of ZnT8 autoantibody measurements. Of the children, 142/227 (63%) were positive for at least three antibodies and the most common combination was insulinoma antigen 2, glutamic acid decarboxylase and ZnT8. ZnT8 autoantibody levels decreased over time after Type 1 diabetes onset and the presence and level of ZnT8 autoantibodies correlated with IA-2 autoantibodies.

CONCLUSIONS

A ZnT8 autoantibody enzyme-linked immunosorbent assay showed 72% disease sensitivity and 99% specificity at Type 1 diabetes onset. Measurements of ZnT8 autoantibodies are important for Type 1 diabetes diagnosis and should be included in the panel of autoantibodies tested at the onset of Type 1 diabetes.

Prepubertal girls with Turner syndrome and children with isolated SHOX deficiency have similar bone geometry at the radius

CONTEXT

The low bone mineral density (BMD) and alterations in bone geometry observed in patients with Turner syndrome (TS) are likely caused by hypergonadotropic hypogonadism and/or by haploinsufficiency of the SHOX gene.

OBJECTIVE

Our objective was to compare BMD, bone geometry, and strength at the radius between prepubertal girls with TS and children with isolated SHOX deficiency (SHOX-D) to test the hypothesis that the TS radial bone phenotype may be caused by SHOX-D.

DESIGN AND SETTING

This comparative cross-sectional study was performed between March 2008 and May 2011 in 5 large centers for pediatric endocrinology.

PATIENTS

Twenty-two girls with TS (mean age 10.3 years) and 10 children with SHOX-D (mean age 10.3 years) were assessed using peripheral quantitative computed tomography of the forearm.

MAIN OUTCOMES

BMD, bone geometry, and strength at 4% and 65% sites of the radius were evaluated.

RESULTS

Trabecular BMD was normal in TS (mean Z-score = -0.2 ± 1.1, P = .5) as well as SHOX-D patients (mean Z-score = 0.5 ± 1.5, P = .3). At the proximal radius, we observed increased total bone area (Z-scores = 0.9 ± 1.5, P = .013, and 1.5 ± 1.4, P = .001, for TS and SHOX-D patients, respectively) and thin cortex (Z-scores = -0.7 ± 1.2, P = 0.013, and -2.0 ± 1.2, P < .001, respectively) in both groups. Bone strength index was normal in TS as well as SHOX-D patients (Z-scores = 0.3 ± 1.0, P = .2, and 0.1 ± 1.3, P = .8, respectively).

CONCLUSIONS

The similar bone geometry changes of the radius in TS and SHOX-D patients support the hypothesis that loss of 1 copy of SHOX is responsible for the radial bone phenotype associated with TS.

Bone geometry and volumetric bone density at the radius in patients with isolated SHOX deficiency

The short stature homeobox-containing gene (SHOX) plays an important role in bone development and growth. We aimed to assess bone geometry and volumetric bone mineral density at the radius in patients with isolated SHOX deficiency and to relate these bone parameters to the severity of disproportion between the upper and the lower body segment. 17 patients with isolated SHOX deficiency (median age 12.3 yrs, range 6.7-37.2, 12 children and 5 adults) were examined by peripheral quantitative CT (pQCT) at the non-dominant forearm. Results were expressed as Z-scores using published reference data. Linear regression analyses were performed to describe associations between pQCT parameters and the severity of disproportion expressed as sitting height to standing subischial leg height ratio. Trabecular volumetric bone mineral density (vBMD) at the distal radius was normal, whereas cortical vBMD was decreased (mean Z-scores 0.34±1.5, n.s., and -2.2±2.2, p<0.001, respectively). Total bone cross-sectional area was enlarged at the diaphysis (2.1±1.2, p<0.001), while cortical bone cross-sectional area was normal (-0.51±1.4, n.s.). Consequently, cortical thickness was decreased (-1.2±1.3, p<0.01). The polar strength-strain index as a surrogate of long bone strength was normal (0.40±1.4, n.s.). We found no associations between pQCT parameters and the severity of disproportion.

CONCLUSIONS

Patients with isolated SHOX deficiency are characterized by decreased cortical vBMD and cortical thickness and enlarged diaphysis. As similar changes have been described in girls with Turner syndrome, these findings suggest that haploinsufficiency of SHOX could cause characteristic skeletal anomalies at the radius.

The effect of diabetes-associated autoantigens on cell processes in human PBMCs and their relevance to autoimmune diabetes development

Type 1 Diabetes (T1D) is considered to be a T-helper- (Th-) 1 autoimmune disease; however, T1D pathogenesis likely involves many factors, and sufficient tools for autoreactive T cell detection for the study of this disease are currently lacking. In this study, using gene expression microarrays, we analysed the effect of diabetes-associated autoantigens on peripheral blood mononuclear cells (PBMCs) with the purpose of identifying (pre)diabetes-associated cell processes. Twelve patients with recent onset T1D, 18 first-degree relatives of the TD1 patients (DRL; 9/18 autoantibody positive), and 13 healthy controls (DV) were tested. PBMCs from these individuals were stimulated with a cocktail of diabetes-associated autoantigens (proinsulin, IA-2, and GAD65-derived peptides). After 72 hours, gene expression was evaluated by high-density gene microarray. The greatest number of functional differences was observed between relatives and controls (69 pathways), from which 15% of the pathways belonged to "immune response-related" processes. In the T1D versus controls comparison, more pathways (24%) were classified as "immune response-related." Important pathways that were identified using data from the T1D versus controls comparison were pathways involving antigen presentation by MHCII, the activation of Th17 and Th22 responses, and cytoskeleton rearrangement-related processes. Genes involved in Th17 and TGF-beta cascades may represent novel, promising (pre)diabetes biomarkers.

Metabolic impact of growth hormone treatment in short children born small for gestational age

BACKGROUND

Growth hormone (GH) treatment in short children born small for gestational age (SGA) may result in metabolic changes with potential long-term effects.

METHODS

149 short SGA children (mean birth weight 2.0 ± 0.6 kg, age 5.5 ± 1.5 years, height standard deviation score (SDS) -3.1 ± 0.6) were randomised to: low-dose GH therapy (0.033 mg/kg/day) for 2 years; high-dose GH therapy (0.100 mg/kg/day) for 1 year, or mid-dose GH therapy (0.067 mg/kg/day) for 1 year. Leptin, ghrelin, insulin-like growth factor-I (IGF-I), IGF binding protein-1 (IGFBP-1), lipids, fasting blood glucose and fasting insulin were assessed at baseline, 12 and 24 months.

RESULTS

After 1 year of active treatment, GH significantly reduced serum ghrelin and increased IGF-I SDS and insulin levels. Regression analysis showed an inverse correlation between ghrelin and IGF-I SDS (p < 0.001). Leptin and IGFBP-1 also declined (both p < 0.05). Changes in insulin levels reversed upon discontinuation. Improvements in lipid profile were nonsignificant and fasting blood glucose levels remained within the normal range.

CONCLUSION

In short SGA children, ghrelin and leptin reductions associated with GH treatment may occur through a negative feedback loop of the GH-IGF-I axis. Consequently, via ghrelin and leptin suppression, GH treatment may modify food intake and body composition and potentially improve long-term metabolic outcomes.

Bone geometry and volumetric bone mineral density in girls with Turner syndrome of different pubertal stages

OBJECTIVE

An increased rate of fractures has been reported in patients with Turner syndrome (TS). We aimed to assess bone geometry and volumetric bone mineral density (vBMD) at the radius in girls with TS and to evaluate the relationships between bone parameters and fracture history.

METHODS AND DESIGN

Sixty-seven girls with TS aged 6-19 years treated currently or in the past with growth hormone (GH) and/or oestrogens were examined using peripheral quantitative computed tomography. Results were compared to reference data.

RESULTS

Cortical area and cortical thickness were low in all age groups (all P<0·001). Height-adjusted total bone area at the diaphysis was increased in prepubertal and postpubertal girls (mean Z-score 1·0, P<0·05 for both) and normal in the pubertal group (mean Z-score 0·1). Cortical vBMD was decreased (mean age-specific Z-scores -2·0, -1·6 and -1·0 for prepubertal, pubertal and postpubertal groups, respectively, P<0·01 for all groups). Height- , age- and cortical thickness-adjusted cortical vBMD was positively correlated to the duration of GH therapy (P=0·012) and to oestrogen administration (P=0·047). Girls with a history of fractures had lower total vBMD at the metaphysis compared to nonfractured TS girls (mean Z-scores -1·7 vs-0·9, P=0·04).

CONCLUSIONS

There is a cortical bone deficit in girls with TS characterized by low cortical area, thin cortex and probably decreased cortical vBMD. Early commencement of GH therapy, as well as oestrogen replacement, is associated with higher cortical vBMD. Further studies should investigate the potential causality of this relation.

HNF1A mutation presenting with fetal macrosomia and hypoglycemia in childhood prior to onset of overt diabetes

BACKGROUND

HNF1A-MODY (MODY3) is a common subtype of autosomal dominant diabetes. Unlike HNF4-MODY where fetal macrosomia and early postnatal hyperinsulinemic hypoglycemia have been reported, history of transient insulin overproduction has not yet been recognized in individuals with HNF1A-MODY.

CASE REPORT

Here, we report on a 40-year-old male patient with HNF1A mutation p.Arg272His (c.815G>A) having a history of fetal macrosomia (4750 g, 59 cm), and, at least, one attack of symptomatic hypoglycemia in childhood. Diabetes was subsequently diagnosed at 19 years of age. The proband's daughter who developed diabetes at 16 years carries the same mutation, but her birth weight and length were in the upper normal range, and she never experienced hypoglycemic symptoms.

CONCLUSION

The observation of fetal macrosomia and hypoglycemia in childhood is indicative of a biphasic impact of the HNF1A mutation on p-cell function over the lifespan, leading from inappropriate insulin oversecretion to final clinical diabetes.

Glucokinase diabetes in 103 families from a country-based study in the Czech Republic: geographically restricted distribution of two prevalent GCK mutations

BACKGROUND

Glucokinase diabetes, also called GCK-MODY or maturity-onset diabetes of the young type 2 (MODY2), is caused by heterozygous mutations in the gene encoding glucokinase (GCK).

OBJECTIVE

The aim of study was to investigate the current prevalence of GCK mutations in a large cohort of Czech patients with typical clinical appearance of GCK-MODY. In addition, we reanalyzed the negative results obtained previously by screening using the denaturing high-performance liquid chromatography (dHPLC).

METHODS

We studied 140 unrelated Czech probands with clinical picture of GCK-MODY who were referred to our center from the whole of the Czech Republic between the years 1999-2009 by direct sequencing of GCK gene.

RESULTS

A mutation in GCK was identified in 103 of 140 probands (74%). We identified 46 different GCK mutations of which 13 were novel. Several mutations were detected in multiple families: p.Glu40Lys (20 families), p.Gly318Arg (12), p.Leu315His (7) and p.Val33Ala (six families). Direct sequencing detected a GCK mutations in 9 of 20 previously dHPLC-negative samples; the sensitivity of the dHPLC screening was calculated as 84%.

CONCLUSIONS

The study shows a relatively high proportion of GCK mutations among individuals with GCK-like phenotype, confirming the effectiveness of carefully applied clinical criteria prior to genetic testing. In the Czech MODY registry, GCK-MODY represents the biggest subgroup of MODY (35%). We report several prevalent GCK mutations with a likely founder effect in the Czech population. Furthermore, our results provide ground for a possible recommendation to reinspect all negative results previously obtained by screening using dHPLC.

Biosimilars: controversies as illustrated by rhGH

Abstract Background and scope: Similar biological medicinal products, also called 'biosimilars', are copies of biopharmaceutical products whose patent has expired. Whether biosimilars are truly comparable and interchangeable with their reference biopharmaceutical products in terms of quality, efficacy and tolerability, is still a matter of debate. This review discusses the controversies related to the criteria for regulatory approval of biosimilars. These concerns are illustrated using recombinant human growth hormone (rhGH) biosimilars as an example.

METHODS

Publications on the regulatory approval of biosimilars in general and rhGH biosimilars in particular were searched in MEDLINE by exploding and combining the medical subject heading terms 'human growth hormone', 'efficacy' or 'safety' and the free-text words 'biosimilar', 'biopharmaceutical', 'similar biological medicinal product', 'follow-up biologic' or 'biogeneric'. Searches were limited to full-text English-language articles. The websites from the European Medicines Agency (EMA) and from the American Food and Drug Administration were also consulted. Regulatory status: To obtain regulatory approval of a biosimilar product by EMA, demonstration of comparability with an approved reference biopharmaceutical product in terms of quality, efficacy and tolerability is needed. Thus, comparative quality studies, non-clinical and clinical efficacy and tolerability studies are required. However, in contrast to the reference product, comparative non-clinical pharmacokinetics, safety pharmacology, reproduction toxicology, mutagenicity and carcinogenicity studies are not mandatory to obtain approval of a biosimilar. In addition, comparable efficacy and tolerability only needs to be established by one study in a single population during a limited time interval (12 months) and often allows extrapolation to all other approved indications of the reference product. Consequently, for the currently approved rhGH biosimilars, long-term efficacy and tolerability in all indications has not been proven to the same degree as for the reference products.

CONCLUSIONS

The validity of the current criteria for comparability and interchangeability of biosimilars and their reference products remains controversial. The authors conclude that long-term clinical investigations and systematic monitoring of the efficacy and tolerability of rhGH biosimilars in all indications are needed. In addition, the medico-economical environment should allow physicians to take a free and informed decision about the type of rhGH to be prescribed.

Anti-GAD65 reactive peripheral blood mononuclear cells in the pathogenesis of cystic fibrosis related diabetes mellitus

OBJECTIVE

A role of autoreactive T cells for type 1 diabetes pathogenesis is considered crucial. In our pilot study we addressed if autoreactive mononuclear cells are present also in peripheral blood of patients with other specific forms of diabetes as cystic fibrosis related diabetes (CFRD).

METHODS

Cellular immune responses to a known beta-cell autoantigen (GAD65 and GAD65 derived peptides) were analysed by ELISPOT (IFN-gamma) and by protein microarray analysis in four patients suffering from CFRD, in four cystic fibrosis (CF) patients without diabetes, in eight type 1 diabetes patients (without CF) and in four healthy controls.

RESULTS

Response to the autoantigen GAD65 (protein and peptides) was observed in 7/8 patients suffering from CF and in all type 1 diabetes patients. Post-stimulation production of Th1 cytokines (IFN-gamma, TNF-beta) was observed in 2/4 CFRD, 1/4 CF patients and in 7/8 type 1 diabetes patients. All these patients carry prodiabetogenic HLA-DQ genotype. Th2- and Th3 type of cytokine pattern was observed in 2/4 CF patients. Production of IL-8 was observed in the third CFRD as well as in the third CF patient and in 1/8 type 1 diabetes patient and borderline production of this chemokine was also observed in 2/4 healthy controls. No reaction was observed in the other 2/4 healthy controls and in the fourth CFRD patient who carried a strongly protective genotype and did not produce autoantibodies. The most potent peptide of GAD65 was amino acids 509-528.

CONCLUSIONS

We consider our observations as a sign of a reaction directed against the self-antigen GAD65 that are closely connected to type 1 diabetes. In CF patients who do not develop diabetes autoreactive mechanisms are very probably efficiently suppressed by immune self-tolerance mechanisms. CFRD patients are a heterogenic group. To disclose those who may display features of autoimmune diabetes could have an impact for their therapy and prognosis.

Protein microarray analysis as a tool for monitoring cellular autoreactivity in type 1 diabetes patients and their relatives

BACKGROUND

Autoreactive T cells have a crucial role in type 1 diabetes (T1D) pathogenesis.

OBJECTIVES

The aim of our study was to monitor the in vitro production of cytokines by peripheral blood mononuclear cells (PBMCs) after stimulation with diabetogenic autoantigens.

SUBJECTS

Ten T1D patients (tested at the time of diagnosis and 6 and 12 months later), 10 first-degree relatives of the T1D patients, and 10 controls underwent the study.

METHODS

PBMCs were stimulated with glutamic acid decarboxylase 65 (GAD65) amino acids (a.a.) 247-279, 509-528, and 524-543; proinsulin a.a. 9-23; and tyrosine phosphatase (islet antigen-2)/R2 a.a. 853-872. Interleukin (IL)-2, IL-4, IL-5, IL-6, IL-10, IL-13, interferon (IFN)-gamma, tumor necrosis factor beta, transforming growth factor beta1, and granulocyte colony-stimulating factor (GCSF) were analyzed by protein microarray.

RESULTS

Differences in cytokine(s) poststimulatory and mainly in basal production were observed in all groups. The most prominent findings were in controls, the higher basal levels of IL-2, IL-4, IL-5, IL-13, and GCSF were observed when compared with relatives (p < 0.05, for all). After stimulation in controls, there was a significant decrease in IL-2, IL-13, GCSF, and IFN-gamma (p < 0.05, for all). The group of relatives was the most variable in poststimulatory production. A strong correlation between cytokines production was found but groups differed in this aspect.

CONCLUSION

By multiplex analysis, it may be possible, for example, to define the risk immunological response pattern among relatives or to monitor the immune response in patients on immune modulation therapy.

No independent role of the -1123 G>C and+2740 A>G variants in the association of PTPN22 with type 1 diabetes and juvenile idiopathic arthritis in two Caucasian populations

INTRODUCTION

The PTPN22 is a negative regulator of the T cell response. Its +1858C>T (R620W) polymorphism has been shown to associate with a risk for multiple autoimmune diseases, including type 1 diabetes (T1D) and juvenile idiopathic arthritis (JIA). The minor (susceptibility) allele is absent in Asian populations, but a recent study suggested an independent involvement of another polymorphism located within the promoter -1123 nucleotides relative to the translational start site.

AIMS

We aimed to analyse the association of three PTPN22 polymorphisms in two distinct Caucasian populations, the Czechs (with T1D and with JIA) and Azeri (with T1D).

METHODS

The single nucleotide polymorphisms (SNP) at positions -1123 (rs2488457), +1858 (rs2476601, the R620W substitution), and +2740 (rs1217412) were genotyped using TaqMan assays in 372 subjects with childhood-onset T1D, 130 subjects with JIA, and 400 control subjects of Czech origin, and in 160 subjects with T1D and 271 healthy controls of Azeri origin.

RESULTS

In the Czechs, all three SNPs were in a tight linkage disequlibrium, while in the Azeri, the linkage disequlibrium was limited to between the promoter and 3'-UTR polymorphism, D'(-1123, +2740)=0.99, r(2)=0.72. Haplotype reconstruction via the expectation-maximization algorithm showed in both populations that only the haplotype containing the minor (W) allele at codon 620 was associated with T1D (OR=2.26, 95% CI 1.68-3.02 in Czechs, OR=14.8, 95% CI 2.0-651 in Azeri) or JIA (OR=2.43, 95% CI 1.66-3.56 in Czechs). The haplotypes having the wild-type (R) allele at codon 620 and minor alleles at -1123 and/or +2740 were neutral as to the risk of autoimmune conditions in both populations.

CONCLUSIONS

In two different Caucasian populations, the Czechs and the Azeri, no independent contribution can be detected either of the -1123 promoter SNP or the +2740 3'-UTR SNP, and only the minor allele at PTPN22 codon 620 contributes to the risk of autoimmunity.

Immune Regulatory T Cells in Siblings of Children Suffering from Type 1 Diabetes Mellitus

Patients with type 1 diabetes are suffering from defects in immune regulatory cells. Their siblings may be at increased risk of type 1 diabetes especially if they are carriers of certain human leucocyte antigen (HLA) alleles. In a prospective non-randomized study, we intended to evaluate 31 healthy siblings of paediatric patients with type 1 diabetes and explore immune regulatory populations of CD4+CD25+ T cells and natural killer (NK) T cells. Tested siblings of type 1 diabetes patients were stratified according to the HLA-associated risk of possible diabetes development. Immune regulatory function of CD4+CD25+ T cells was tested in vitro. Significant differences in CD4+CD25+ but not in NK T cells have been identified. Siblings of type 1 diabetes patients carrying high risk HLA alleles (DQA1*05, DQB1*0201, DQB1*0302) had significantly lower number of immune regulatory CD4+CD25+ T cells than the age-matched healthy controls or siblings carrying low-risk HLA alleles (DQB1*0301, DQB1*0603, DQB1*0602). Regulatory function of CD4+CD25+ T cells demonstrated a dose-escalation effect. In siblings of type 1 diabetes patients, the defect in immune regulatory CD4+CD25+ T cells exists in association with genetic HLA-linked risk for type 1 diabetes.

High prevalence of coeliac disease in siblings of children with type 1 diabetes

Coeliac disease has been shown to occur more frequently among first-degree relatives of diabetic patients than in the general population. Our objective was to assess the prevalence of endomysium antibodies (EMA) in non-diabetic siblings of Czech diabetic children and to evaluate the effects of HLA-DQ polymorphisms in determining the genetic susceptibility to coeliac disease (CD) in these subjects. We investigated 240 siblings of diabetic children from 213 families (125 males and 115 females, aged 12.6+/-4.9 years, mean +/- SD). All subjects were tested for the total IgA level to exclude IgA deficiency, and for endomysium IgA to disclose CD. In five IgA-deficient subjects, anti-gliadin IgG was used instead. Small bowel biopsy was offered to subjects with confirmed positive EMA. The HLA-DQA1, -DQB1 genotypes were determined using PCR-SSP. Positive EMA were found in 9/240 (3.8%) subjects (three males, six females). The biopsy confirmed CD in six children, two had a normal mucosal finding and one refused the biopsy. The HLA-DQ2 polymorphism was more frequent among siblings with EMA (seven of nine) than in siblings without EMA (33%), corrected P = 0.031.

CONCLUSION

The 3.8% frequency of coeliac disease found in siblings of diabetic children is close to the 4.3% found previously in Czech children with type 1 diabetes mellitus and is substantially higher than the rate in the healthy children population.

Growth data in large series of 587 children and adolescents with type 1 diabetes mellitus

OBJECTIVE

Discordant data were found in recent growth studies in children with type-1 diabetes mellitus. This study focuses on growth data and final height in the largest cohort of diabetic children studied so far.

METHODS

7598 growth data collected in a longitudinal/cross sectional way between 1971 and 1996 in 587 diabetic subjects (317 males, 270 females) were available for analysis of height and BMI, together with 3889 HbA1c measurements. Final height data were correlated with target height in 123 subjects. The individual growth and BMI linear regression curve of each patient was compared to growth standards and correlated with HbA1c.

RESULTS

Children of both sexes were taller at the first observation (males, SDS 0.15 +/- 1.10, mean +/- SD, P=0.02, females, SDS 0.74 +/- 1.46, P<0.001) and tended to lose height afterwards (males, P<0.001, females, n.s.). Males reached a final height of 176.5 cm (n=62, target height 176.8, n.s.) and females 167.0 cm (n=61, target height 165.6, n.s.). Children of both sexes had a higher than normal BMI at first observation (males, SDS 0.32 +/- 1.31, P<0.001, females, SDS 0.10 +/- 0.52, P=0.02). Females but not males gained weight over-proportionally afterwards. HbA1c did not predict any of the variables.

CONCLUSION

Diabetic children are taller close to the diabetes onset, which may be due to the synchronization of onset of diabetic symptoms with the mid-childhood growth spurt or the pubertal growth spurt accompanied by elevated growth hormone and/or androgen levels and increased insulin resistance. The subsequent growth deceleration may represent a physiological lag-down growth. This concept is supported by normal adult heights following growth deceleration.