A comparative study using insulin pump therapy and continuous glucose monitoring in newly diagnosed very young children with type 1 diabetes: it is possible to bend the curve of HbA1c

AIMS

The target of metabolic control (HbA1c < 7% or 53 mmol/mol) recommended by the ADA and ISPAD is attained by 30% of children with Type 1 Diabetes (T1D). Advances in technologies for T1D aim to improve metabolic outcomes and reduce complications. This observational study assesses the long-term outcomes of advanced technologies for treatment of T1D compared to conventional approach started at onset in a group of very young children with T1D.

METHODS

54 patients with less 4 years old at onset of T1D were enrolled and followed for up to 9 years after diagnosis. 24 subjects started continuous subcutaneous insulin (CSII) treatment and 30 subjects received MDI therapy from onset. Auxological data, HbA1c and total daily insulin dose (TDD/kg) have been collected at admission and every 4 months. HbA1cAUC>6%, rates of acute complications, glycemic variability indices and glucometrics were also recorded.

RESULTS

Patients with CSII therapy had significantly lower mean HbA1c values compared to subjects receiving MDI treatment. CSII approach also recorded lower mean HbA1cAUC>6% and TDD/kg than MDI therapy. At the last download data, the time in range (TIR) was higher in patients with CSII and hyperglycemia events were lower. Better glycemic variability indices have been described during CSII therapy, including mean glycemia, standard deviation, coefficient of variation (CV), glycemia risk index (GRI) and high blood glucose index (HBGI). There was no statistically significant difference between frequency of severe hypoglycemia and ketoacidosis episodes between groups.

CONCLUSIONS

Early initiation of diabetes technologies is safe and able to determine a better long term glycemic control in young children with T1D. It also allows to flatten the trajectory of HbA1c, probably reducing microvascular, macrovascular and neurological complications of diabetes in this very peculiar age group.

Genetic determinants of type 1 diabetes in individuals with weak evidence of islet autoimmunity at disease onset

AIMS/HYPOTHESIS

Islet autoantibodies (AAbs) are detected in >90% of individuals with clinically suspected type 1 diabetes at disease onset. A single AAb, sometimes at low titre, is often detected in some individuals, making their diagnosis uncertain. Type 1 diabetes genetic risk scores (GRS) are a useful tool for discriminating polygenic autoimmune type 1 diabetes from other types of diabetes, particularly the monogenic forms, but testing is not routinely performed in the clinic. Here, we used a type 1 diabetes GRS to screen for monogenic diabetes in individuals with weak evidence of autoimmunity, i.e. with a single AAb at disease onset.

METHODS

In a pilot study, we genetically screened 142 individuals with suspected type 1 diabetes, 42 of whom were AAb-negative, 27 of whom had a single AAb (single AAb-positive) and 73 of whom had multiple AAbs (multiple AAb-positive) at disease onset. Next-generation sequencing (NGS) was performed in 41 AAb-negative participants, 26 single AAb-positive participants and 60 multiple AAb-positive participants using an analysis pipeline of more than 200 diabetes-associated genes.

RESULTS

The type 1 diabetes GRS was significantly lower in AAb-negative individuals than in those with a single and multiple AAbs. Pathogenetic class 4/5 variants in MODY or monogenic diabetes genes were identified in 15/41 (36.6%) AAb-negative individuals, while class 3 variants of unknown significance were identified in 17/41 (41.5%). Residual C-peptide levels at diagnosis were higher in individuals with mutations compared to those without pathogenetic variants. Class 3 variants of unknown significance were found in 11/26 (42.3%) single AAb-positive individuals, and pathogenetic class 4/5 variants were present in 2/26 (7.7%) single AAb-positive individuals. No pathogenetic class 4/5 variants were identified in multiple AAb-positive individuals, but class 3 variants of unknown significance were identified in 19/60 (31.7%) patients. Several patients across the three groups had more than one class 3 variant.

CONCLUSIONS/INTERPRETATION

These findings provide insights into the genetic makeup of patients who show weak evidence of autoimmunity at disease onset. Absence of islet AAbs or the presence of a single AAb together with a low type 1 diabetes GRS may be indicative of a monogenic form of diabetes, and use of NGS may improve the accuracy of diagnosis.

Combined unsupervised and semi-automated supervised analysis of flow cytometry data reveals cellular fingerprint associated with newly diagnosed pediatric type 1 diabetes

An unbiased and replicable profiling of type 1 diabetes (T1D)-specific circulating immunome at disease onset has yet to be identified due to experimental and patient selection limitations. Multicolor flow cytometry was performed on whole blood from a pediatric cohort of 107 patients with new-onset T1D, 85 relatives of T1D patients with 0-1 islet autoantibodies (pre-T1D_LR), 58 patients with celiac disease or autoimmune thyroiditis (CD_THY) and 76 healthy controls (HC). Unsupervised clustering of flow cytometry data, validated by a semi-automated gating strategy, confirmed previous findings showing selective increase of naïve CD4 T cells and plasmacytoid DCs, and revealed a decrease in CD56brightNK cells in T1D. Furthermore, a non-selective decrease of CD3+CD56+ regulatory T cells was observed in T1D. The frequency of naïve CD4 T cells at disease onset was associated with partial remission, while it was found unaltered in the pre-symptomatic stages of the disease. Thanks to a broad cohort of pediatric individuals and the implementation of unbiased approaches for the analysis of flow cytometry data, here we determined the circulating immune fingerprint of newly diagnosed pediatric T1D and provide a reference dataset to be exploited for validation or discovery purposes to unravel the pathogenesis of T1D.

6128Losartan vs Nebivolol vs the association of both on the progression of aortic root dilation in genotyped Marfan Syndrome: 48 months open label randomized controlled phase III trial

Background

Marfan Syndrome (MFS) is a rare multisystemic genetic disease caused by mutations in the Fibrillin 1 (FBN1) gene. Aortic root aneurysm, potentially evolving to dissection and rupture, is the most important clinical complication. Beta blockers (BB) and Angiotensin II receptor blockers (ARB), these latter exerting an anti-TGFbeta1 effect, are current cornerstones of medical therapy in patients diagnosed with MFS and presenting aortic root aneurysm. The study aimed at comparing the effect of single drug (nebivolol and losartan) vs. the combination of both (losartan + nebivolol) in limiting the progression of the growth of the aortic root diameter (ARD) in FBN1 genotyped patients with aortic root aneurysm (z-score>2), who had not undergone prior aortic surgery.

Methods

We designed a controlled, open-label, single-blinded, 1:1:1 randomized, phase III single-centre study [NCT00683124]. Calculated sample size was 291 (power 90%, type I error 5%, 20% attrition, expected dropout 20%). ARD data collection was performed with annual 2D-transthoracic echocardiograms for four years. ARDs were measured with 2D-transthoracic echocardiogram as absolute values, aortic root ratio (ARR), and z-score. The primary endpoint was the modification of ARD z-score at 48 months. The analysis of the primary endpoint aimed at showing differences of ARD z-score comparing:

– The combined treatment arm (group A).

– The group aggregating both single treatment arms (group B).

– The nebivolol arm (group C).

– The losartan arm (group D).

Results

We enrolled 262 patients (126 adults, aged 17–55, and 136 children, aged 1–16); 236/262 (22 dropout; 4 lost at follow-up) completed the planned follow-up: 81 in the group A, 79 in the BB in the group C and 76 in the group D. No patient developed acute aortic dissection. Both drugs administered either individually or in combination were well tolerated without evidence of side effects. At 48 months, the ARD Z-score decreased from baseline to end-follow-up in all treatment arms. The decrease was significantly higher in the combined treatment arm (A) than in the single treatment aggregated arm (group B) with a difference in ARD z-score change of 0.17 (p=0.009) in the combined arm (A). Similarly, the decrease of z-score was inferior in the nebivolol arm and in the losartan arm than in the combined arm (by 0.16, p=0.032, and by 0.18, p=0.019, respectively). After Bonferroni correction for these post-hoc comparisons only the decrease of z-score in the losartan arm remained significantly inferior (p<0.025).

Conclusions

This study shows that the current cornerstones of medical therapy in MFS (ARB and BB) are effective in limiting the progression of the growth of the aortic root diameter: their combination exploits a synergistic effect. The combined administration of BB and ARB in patients with aortic root aneurysm is a sustainable, well tolerated treatment that effectively limits the rate of progression of aortic root dilation.

Acknowledgement/Funding

The financial support of Telethon, Italy (Grant no. GGP08238) is gratefully acknowledged.The drugs are a gift of Menarini and MSD

P5723IEVA: Integration and Extraction of Variant Attributes in NGS analysis

Purpose

This project aimed at reducing NGS errors through the introduction of a bioinformatic solution in the bioinformatic analytic step of the genetic testing process. iEVA is a tool that enhances NGS-derived informative features to use them in a filtering process based on a Machine Learning algorithm (ML). It considers sequencing features (e.g. technical errors, duplicates of PCR) together with nucleotide sequence characteristics.

Methods

To demonstrate the effectiveness of iEVA in eliminating FP and FN errors from the NGS bioinformatic pipeline, we developed two ML-based filtering algorithms. The training dataset consisted of 7968 single nucleotide variants (SNV) and 306 Insertions and Deletions (InDels) validated by Sanger sequencing performed by expert molecular biologists. Variants derived from 800 sequences obtained with the Illumina Trusight Cardio panel containing 174 genes related to cardiovascular diseases. Two Random Forest classifiers were trained with the task of discriminating between sequencing error and real variant. The first one was trained using attributes derived from the most common variant caller (GATK v3.8), and the second one using iEVA results. To evaluate ML models, we used a 3-Fold cross-Validation and validated the results using an independent validation dataset consisting of 3415 SNV and 132 InDels.

Results

Using iEVA attributes, we obtained 1 FP (excluded by Sanger) and 3 FN (confirmed by Sanger) less than using common variant caller attributes. In the independent validation dataset, the iEVA-trained classification model identified 1 Sanger-confirmed variant that was missed by variant caller-trained model.

Conclusions

Variant filtering is crucial to exclude sequencing errors and to recognize true variants. Even a single filtering error may negatively impact on the patient when a genetic diagnosis is missed. To obtain a certain genetic diagnosis, a 0% error probability is needed. The introduction of iEVA in the pipeline is an easy, time- and cost-saving tool to reduce errors and to improve the precision of the genetic data.

Acknowledgement/Funding

Italian Ministry of Health Research Funding to the IRCCS Foundation University Hospital Policlinico San Matteo of Pavia

P5539Genetic heterogeneity of spontaneous coronary artery dissection (SCAD)

Introduction

SCAD is a rare coronary event that may cause acute coronary syndromes (ACS). SCAD predominantly occurs in apparently healthy, young to middle aged women (up to 95% of cases). The known causes include: heritable connective tissue diseases, fibromuscular dysplasia, arteritis, contraceptives, cocaine abuse and chest trauma. A variable proportion of patients manifests progression to longer segments of the same vessel or recurrence of dissection in other coronary arteries. SCAD can be the first manifestation of a previously unrecognised systemic disease.

Methods

In 2010 we started collecting consecutive SCAD, as first clinical manifestation, in patients addressed to our attention for investigation of genetic or non genetic causes, after successful management of the acute phase and exclusion of systemic inflammatory and autoimmune diseases. All patients underwent genetic visit and counselling, collection of clinical reports and imaging records, clinical cardiologic evaluation with pan-angio CT scan, biochemical testing including coagulation-related tests, and and genetic testing of genes causing connective tissue diseases. Parallel clinical family screening and genetic testing were systematically performed.

Results

The series is constituted of 35 patients (28F and 7M) (age at onset, mean ± SD, 44±7.6 years) with ACS-SCAD (20 STEMI and 15 NSTEMI) and 9 second dissections in a different coronary artery. Two sisters had ACS-SCAD caused by dissection of the same coronary artery.

We identified pathologic mutations (n=19/35, 54%) in COL3A1 (n=3), FBN1 (n=1), FBN1+TGFBR1 (n=1), TGFBR1 (n=2), TGFBR2 (n=1), MYLK (n=1), SMAD3 (n=1), COL5A1 (n=1 homozygous), COL5A2 (n=1), MYH11 (n=1), TGFB2 (n=1), ABCC6 (1 homozygous), ELN (2 homozygous sisters and 1 heterozygous unrelated patient), NOTCH1 (n=1). In 8 (23%) patients we identified VUS classified as C3 because previously unreported and predicted as uncertain on the basis of in silico analyses. In the remaining 8 patients we only identified C2 variants. A second SCAD (14 days to 78 months after the first event) occurred in 9 patients (9/35, 25%) (COL3A1 (n=2), FBN1 (n=1), FBN1+TGFBR1 (n=1), MYLK (n=1), COL5A2 (n=1), NOTCH1 (n=1) COL5A2 (n=1) and 1 with a C2 variant in COL3A1. Two patients with thrombocytosis were carriers of the somatic JAK2 V617F mutation. Extra-coronary arterial dilations/aneurysms occurred in 13 families; in the follow-up 2 patients demonstrate dissection in non-coronary arteries.

Conclusions

Our series, with the potential bias of a referral centre for inherited cardiovascular disease, demonstrated that SCAD is the possible first manifestation of a genetic disorder and that neither disease gene or mutation predicts the risk of a second coronary event. SCAD is a potentially fatal coronary event associated with ACS, warning for familial disease and unpredictable risk of recurrence.

Metabolic control and complications in Italian people with diabetes treated with continuous subcutaneous insulin infusion

BACKGROUND AND AIM

The objective of this cross-sectional study was to evaluate the degree of glycaemic control and the frequency of diabetic complications in Italian people with diabetes who were treated with continuous subcutaneous insulin infusion (CSII).

METHODS AND RESULTS

Questionnaires investigating the organisation of diabetes care centres, individuals' clinical and metabolic features and pump technology and its management were sent to adult and paediatric diabetes centres that use CSII for treatment in Italy. Information on standard clinical variables, demographic data and acute and chronic diabetic complications was derived from local clinical management systems. The sample consisted of 6623 people with diabetes, which was obtained from 93 centres. Of them, 98.8% had type 1 diabetes mellitus, 57.2% were female, 64% used a conventional insulin pump and 36% used a sensor-augmented insulin pump. The median glycated haemoglobin (HbA_1c) level was 60 mmol/mol (7.6%). The HbA_1c target (i.e. <58 mmol/mol for age <18 years and <53 mmol/mol for age >18 years) was achieved in 43.4% of paediatric and 23% of adult participants. Factors such as advanced pump functions, higher rate of sensor use, pregnancy in the year before the study and longer duration of diabetes were associated with lower HbA_1c levels. The most common chronic complications occurring in diabetes were retinopathy, microalbuminuria and hypertension. In the year before the study, 5% of participants reported ≥1 episode of severe hypoglycaemic (SH) episodes (SH) and 2.6% reported ≥1 episode of ketoacidosis.

CONCLUSIONS

Advanced personal skills and use of sensor-based pump are associated with better metabolic control outcomes in Italian people with diabetes who were treated with CSII. The reduction in SH episodes confirms the positive effect of CSII on hypoglycaemia.

CLINICAL TRIAL REGISTRATION NUMBER

NCT 02620917 (ClinicalTrials.gov).

Supporting Translational Research on Inherited Cardiomyopathies through Information Technology

Objectives: The INHERITANCE project, funded by the European Commission, is aimed at studying genetic or inherited Dilated cardiomyopathies (DCM) and at understanding the impact and management of the disease within families that suffer from heart conditions that are caused by DCMs. The biomedical informatics research activity of the project aims at implementing information technology solutions to support the project team in the different phases of their research, in particular in genes screening prioritization and new gene-disease association discovery.

Methods: In order to manage the huge quantity of scientific, clinical and patient data generated by the project several advanced biomedical informatics tools have been developed. The paper describes a layer of software instruments to support translation of the results of the project in clinical practice as well as to support the scientific discovery process. This layer includes data warehousing, intelligent querying of the phenotype data, integrated search of biological data and knowledge repositories, text mining of the relevant literature, and case based reasoning.

Results: At the moment, a set of 1,394 patients and 9,784 observations has been stored into the INHERITANCE data warehouse. The literature database contains more than 1,100,000 articles retrieved from the Pubmed and generically related to cardiac diseases, already analyzed for extracting medical concepts and genes.

Conclusions: After two years of project the data warehouse has been completely set up and the text mining tools for automatic literature analysis have been implemented and tested. A first prototype of the decision support tool for knowledge discovery and gene prioritization is available, but a more complete release is still under development.

Necrobiosis Lipoidica Diabeticorum: A pediatric case report

Introduction: Necrobiosis lipoidica (NL) is a rare chronic granulomatous dermatitis that usually appears in the lower extremities. It affects about 0.3–1.2% of diabetic patients, the majority of whom have type 1 diabetes. The etiology and pathogenesis of this disorder are still unclear. NL is characterized by skin rash that usually affects the shins. The average onset is 30 years, with females being affected more commonly. There are very few reported cases of necrobiosis lipoidica in children.

Case report: We report a case of a 16 year old girl affected by type 1 diabetes mellitus (15 years disease duration) who developed an erythematous nodular rash on the lower extremities and interscapular area. In the suspect of necrobiosis lipoidica, a skin biopsy was performed (lower extremities and interscapular area). The microscopic evaluation of the pretibial lesions was suggestive of necrobiosis lipoidica. The smaller lesions in the interscapular area showed signs of perivascular dermatitis which could be consistent with early stages of necrobiosis lipoidica. Local treatment with tacrolimus determined a progressive improvement of the lesions.

Conclusion: In patients with T1DM, diagnosis of NL of the lower legs is usually unequivocal. However, diagnosis may be more challenging in the presence of lesions with recent onset and/or atypical clinical presentation and unusual site. In these cases, NL must always be taken in consideration in order to avoid misdiagnosis, wrong/late treatment decisions and progression to ulceration.

Six cases with severe insulin resistance (SIR) associated with mutations of insulin receptor: Is a Bartter-like syndrome a feature of congenital SIR?

Biallelic insulin receptor (INSR) gene mutations cause congenital syndromes of severe insulin resistance (SIR) known as Donohue syndrome (DS) and Rabson-Mendenhall syndrome (RMS). At presentation, DS and RMS are difficult to differentiate since they share many clinical features; however, while patients with DS usually die within 1 year of birth, individuals classified as RMS can reach adult age. INSR mutations can be also found in pubertal females with hyperinsulinism, hyperandrogenism, and acanthosis nigricans (type A SIR). We studied the INSR gene in five subjects with congenital SIR and in a patient with type A SIR. Nine biallelic INSR gene mutations (eight novels, including an in-frame deletion of INSR signal peptide) were identified in patients with congenital SIR; a heterozygous, spontaneous INSR mutation was detected in the patient with type A SIR. Two probands, presenting severe hirsutism at birth, died at the age of 3 months and were classified as DS, while other 2, currently 2 and 3 years old, were diagnosed with RMS (patients 3 and 4). The fifth patient with congenital SIR died when 14 months old. Nephrocalcinosis, hyperaldosteronism, hyperreninemia, and hypokalemia, in the absence of hypertension, were discovered in patients 3 and 5 when 24 and 4 months old, respectively. Patient 3, now 3 years/3 months old, still shows hyperreninemic hyperaldosteronism requiring potassium supplementation. We conclude that renal abnormalities resembling antenatal Bartter's syndrome type II, recently reported also by others, is a common observation in patients with congenital SIR.

Future Perspectives in Glucose Monitoring Sensors

The prevalence of diabetes is increasing. improved glucose control is fundamental to reduce both long-term micro- and macrovascular complications and short-term complications, such as diabetic ketoacidosis and severe hypoglycemia. Frequent blood glucose monitoring is an essential part of diabetes management. However, almost all available blood glucose monitoring devices are invasive. This determines a reduced patient compliance, which in turn reflects negatively on glucose control. Therefore, there is a need to develop noninvasive glucose monitoring devices that will reduce the need of invasive procedures, thus increasing patient compliance and consequently improving quality of life and health of patients with diabetes.

Future Perspectives in Glucose Monitoring Sensors

The prevalence of diabetes is increasing. Improved glucose control is fundamental to reduce both long-term micro- and macrovascular complications and short-term complications, such as diabetic ketoacidosis and severe hypoglycemia. Frequent blood glucose monitoring is an essential part of diabetes management. However, almost all available blood glucose monitoring devices are invasive. This determines a reduced patient compliance, which in turn reflects negatively on glucose control. Therefore, there is a need to develop noninvasive glucose monitoring devices that will reduce the need of invasive procedures, thus increasing patient compliance and consequently improving quality of life and health of patients with diabetes.

Sensor-augmented pump therapy in very young children with type 1 diabetes: an efficacy and feasibility observational study

BACKGROUND

Efficacy and feasibility of sensor-augmented pump (SAP) therapy were evaluated in very young children with type 1 diabetes (T1D).

SUBJECTS AND METHODS

SAP (Dexcom [San Diego, CA] Seven Plus™ usage combined with insulin pump) therapy was retrospectively evaluated in 28 children (15 boys) younger than 7 years (mean age, 5.8 ± 1.2 years; range, 3-7 years), with T1D. Glycosylated hemoglobin (HbA1c) was evaluated at baseline and at the end of the study, as were efficacy and feasibility of the system, using a rating scale (with 3 being the most positive).

RESULTS

SAP has been used for at least 6 months by 85% of patients, with an overall good satisfaction (92%). The greatest perceived benefit was the reduced fear of hypoglycemia (score of 3, 81%). HbA1c significantly improved only in patients with baseline HbA1c >7.5% (P = 0.026).

CONCLUSIONS

SAP therapy is effective and feasible in preschool children with T1D. In patients with high HbA1c at baseline it provide a 0.9% decrease, sustained for at least 6 months.