Prediction of type 1 diabetes in Sardinian schoolchildren using islet cell autoantibodies: 10-year follow-up of the Sardinian schoolchildren type 1 diabetes prediction study.

AIMS: Stable genetic background makes individuals from the Mediterranean island of Sardinia ideal to define the predictive power of islet-related autoantibodies (IRAs): glutamic acid decarboxylase antibodies (GADA), tyrosine phosphatase-like antibodies (IA-2A), islet cell antibodies (ICA) to identify T1DM progressors. The aims of the present study were: (1) determination of IRAs reference limits in healthy non-diabetic Sardinian schoolchildren (SSc). (2) Predictive power evaluation of IRAs as single or combined determination to identify islet to identify T1DM progressors. METHODS: Between 1986 and 1994, 8448 SSc were tested for IRAs. All were followed up for 10 years. The predictive power of single or combination of IRAs was determined as hazard ratio (HR), sensitivity, specificity, area under the ROC curve, negative and positive predictive value (NPV, PPV). RESULTS: All 43 progressors to T1DM, but three showed at least one autoantibody positivity. HR for any single-autoantibody positivity was 55.3 times greater when compared to SSc negative for all IRAs. Any single autoantibody performed at least 64.9 % sensitivity with PPV always lower than 16 %. The best performing combination was ICA, plus IA-2A (showing 52.6 % sensitivity, 99.8 % specificity, 0.76 area under the ROC curve, 51.3 % PPV and 99.8 % NPV. CONCLUSIONS: Determination of IRAs reference limits in healthy SSc by standard statistical methods is crucial to establish the power of IRAs as progression markers to T1DM. Our data offer a solid rationale for future testing of ICA and IA-2A as routine laboratory markers to identify individuals at high risk of T1DM in the general population.

Autoimmune diseases and celiac disease which came first: genotype or gluten?

Celiac disease (CD) is associated with several autoimmune diseases (ADs) and, in particular, thyroid autoimmunity (TA) and Type 1 diabetes (T1D). TA and T1D are defined as 'associated conditions' to CD (conditions at increased prevalence in CD but not directly related to gluten ingestion). The diagnosis of CD may precede or follow that of TA/T1D. To date, the available evidence suggests that the common genetic background is the main factor determining the high prevalence of the association. Conversely, no conclusive findings clarify whether extrinsic gluten-related factors (age at the first introduction, concomitant breastfeeding, length of gluten exposure and gluten-free diet) may link CD to the ADs. The aim of this review is to evaluate whether genetic background alone could explain the association between CD and ADs or if gluten-related factors ought to be considered. The pathophysiological links clarifying how the gluten-related factors could predispose to ADs will also be discussed.

Hyper-activation of Notch3 amplifies the proliferative potential of rhabdomyosarcoma cells.

Rhabdomyosarcoma (RMS) is a pediatric myogenic-derived soft tissue sarcoma that includes two major histopathological subtypes: embryonal and alveolar. The majority of alveolar RMS expresses PAX3-FOXO1 fusion oncoprotein, associated with the worst prognosis. RMS cells show myogenic markers expression but are unable to terminally differentiate. The Notch signaling pathway is a master player during myogenesis, with Notch1 activation sustaining myoblast expansion and Notch3 activation inhibiting myoblast fusion and differentiation. Accordingly, Notch1 signaling is up-regulated and activated in embryonal RMS samples and supports the proliferation of tumor cells. However, it is unable to control their differentiation properties. We previously reported that Notch3 is activated in RMS cell lines, of both alveolar and embryonal subtype, and acts by inhibiting differentiation. Moreover, Notch3 depletion reduces PAX3-FOXO1 alveolar RMS tumor growth in vivo. However, whether Notch3 activation also sustains the proliferation of RMS cells remained unclear. To address this question, we forced the expression of the activated form of Notch3, Notch3IC, in the RH30 and RH41 PAX3-FOXO1-positive alveolar and in the RD embryonal RMS cell lines and studied the proliferation of these cells. We show that, in all three cell lines tested, Notch3IC over-expression stimulates in vitro cell proliferation and prevents the effects of pharmacological Notch inhibition. Furthermore, Notch3IC further increases RH30 cell growth in vivo. Interestingly, knockdown of Notch canonical ligands JAG1 or DLL1 in RMS cell lines decreases Notch3 activity and reduces cell proliferation. Finally, the expression of Notch3IC and its target gene HES1 correlates with that of the proliferative marker Ki67 in a small cohort of primary PAX-FOXO1 alveolar RMS samples. These results strongly suggest that high levels of Notch3 activation increase the proliferative potential of RMS cells.

Celiac disease and endocrine autoimmune disorders in children: an update.

Celiac disease (CD) is a life-long inflammatory condition of the gut that occurs in genetically susceptible individuals. Several autoimmune diseases (AI) are associated with CD. To date, no conclusive evidence is available that proves if the relationship between CD and AI is mediated by gluten exposure, or if CD and AI could co-occur due to other causes, in particular the loss of the intestinal barrier function and the common genetic background. Furthermore, it is not clear yet if CD needs a regular screening program for AI. This review will cover the key studies on both the pathogenetic and clinical evidence explaining this association. We will review the reports including patients aged <18 years with CD and endocrine AI.

Nonalcoholic fatty liver disease in children.

PURPOSE OF REVIEW: The intent of this review is to provide a concise overview of all recent acquisitions in terms of therapies and early noninvasive diagnostic approaches for nonalcoholic fatty liver disease (NAFLD) in children. RECENT FINDINGS: NAFLD is increasingly being diagnosed in children. If undiscovered and if certain risks are present (i.e. obesity), nonalcoholic steatohepatitis, the most severe form of NAFLD, may silently progress to cirrhosis, hepatocarcinoma and liver-related death in adulthood. Current therapies include approaches for reducing the incidence of risk factors (i.e. weight reduction), drugs targeting the major molecular mechanisms thought essential in the pathogenesis of the disease (insulin resistance and oxidative stress) or both, but other novel treatments are under investigation. SUMMARY: Although weight reduction, achieved through a combination of diet and exercise, makes it possible to modify the natural course of simple steatosis, the addition of adequate drugs might also provide a therapeutic action on nonalcoholic steatohepatitis. Moreover, preventive strategies and the design and translation into clinical practice of indices that integrate noninvasive diagnostic tools and serum biomarkers might be a winning approach for improving management of paediatric NAFLD/nonalcoholic steatohepatitis in the coming years.

Type 1 diabetes risk and autoantibody positivity in Sardinian migrants in the province of Pavia.

BACKGROUND: Type 1 diabetes is an autoimmune disease. Genetics as well as environmental factors seem to play a role in the pathogenesis of type 1 diabetes. AIMS: We sought to investigate the possible relationship between migration from Sardinia to a low incidence area of type 1 diabetes (Lombardy) and the prevalence of autoantibody positivity. METHODS: We enrolled 554 Sardinian immigrants and 226 of their offspring. All subjects underwent a complete anamnestic evaluation. Fasting blood glucose, HbA1c, GADA and IA-2 were measured in all study participants. Additionally, the presence of risk haplotypes (HLA-DR3 -DR4 and DQB1/0302) was determined. After a seven-year follow-up, high genetic risk and/or autoantibody positivity subjects were re-evaluated. RESULTS: Among Sardinian immigrants, the prevalence of type 1 diabetes was 0.9%, while in the offspring group, the prevalence was 0.4%. After removing type 1 diabetic patients, the GADA prevalence was 2.4% in the immigrant group and 3.8% among their offspring. Among Sardinian immigrants, the IA-2 prevalence was 0.7%, while all offspring were IA-2 negative. After a seven-year follow-up, 85.7% of GADA-positive migrants had persistent GADA positivity. Two GADA-negative offspring subjects turned positive. None of the study participants developed diabetes during the follow-up. CONCLUSIONS: The present study showed a higher prevalence of GADA positivity within Sardinian immigrants at high genetic risk; GADA positivity may represent the first detectable phase of type 1 diabetes. After a seven-year follow-up, none of the high genetic/antibody risk group subjects developed type 1 diabetes. However, it seems reasonable to strictly control high-risk individuals in order to diagnose subclinical diabetes.

Identification of tyrosine phosphatase 2(256-760) construct as a new, sensitive marker for the detection of islet autoimmunity in type 2 diabetic patients: the non-insulin requiring autoimmune diabetes (NIRAD) study 2.

OBJECTIVE: The presence of autoantibodies to islet antigens GAD and/or tyrosine phosphatase 2 (IA-2) in type 2 diabetic patients (latent autoimmune diabetes in adults [LADA]) identifies subjects at high risk to develop insulin dependency. The aim of this study was to dissect humoral anti-IA-2 immune response in Caucasian LADA patients, identifying the most sensitive construct to evaluate IA-2 immunoreactivity and comparing LADA IA-2 epitope specificities to those found in type 1 diabetes. RESEARCH DESIGN AND METHODS: We analyzed 177 LADA and 978 type 2 diabetic patients with different disease duration, collected in a nationwide Italian survey, the Non-Insulin Requiring Autoimmune Diabetes (NIRAD) study aimed at assessing prevalence and characteristics of autoimmune diabetes in type 2 diabetic patients and 106 newly diagnosed type 1 diabetic patients (53 children, 53 adults). By radioimmunoassay, we analyzed humoral immunoreactivity to seven IA-2 constructs: IA-2(PTP (687-979)), IA-2((761-964)), IA-2((256-760)), IA-2(JM (601-630)), IA-2(IC (605-979)), IA-2(BDC (256-556:630-979)), and IA-2(FL (1-979)). RESULTS: IA-2((256-760)) fragment was identified as the marker with the highest sensitivity for detection of humoral IA-2 immunoreactivity in LADA patients, identifying IA-2 autoantibodies in approximately 30% of GAD antibody (GADA)-positive LADA patients and in 3.4% of GADA-negative type 2 diabetic patients. LADA IA-2((256-760))A positivity was associated with an increased frequency of autoimmune diabetes HLA-susceptible genotypes and with a higher risk for developing thyroid autoimmunity compared with autoantibody-negative type 2 diabetic patients. At disease diagnosis, adult-onset type 1 diabetic and LADA patients showed a lower IA-2 COOH-terminal immunoreactivity compared with childhood-onset type 1 diabetic patients. CONCLUSIONS: IA-2 immunoreactivity in LADA patients has thus far been underestimated, and IA-2((256-760)) autoantibody detection may represent a novel diagnostic tool for the identification of islet autoimmunity in these patients.

Hearing impairment in congenital diaphragmatic hernia: the inaudible and noiseless foot of time.

AIM OF THE STUDY: Infants with congenital diaphragmatic hernia (CDH) are at high risk of sensorineural hearing loss (SNHL). Extracorporeal membrane oxygenation is known to increase this risk, but little is known about other potential causes. We evaluated the impact of several risk factors on SNHL development in CDH survivors not treated with extracorporeal membrane oxygenation. METHODS: All high-risk CDH survivors consecutively treated between 1999 and 2005 were included. SNHL was diagnosed based on formal assessment with standard audiologic tests. Patients with and without SNHL were compared for patient-related and treatment-related risk factors. Subsequently, a logistic regression analysis was performed to identify independent risk factors associated with SNHL development. MAIN RESULTS: Out of 87 CDH survivors, 82 had a formal audiologic evaluation and 40 (49%) had SNHL. Patients with SNHL had significantly lower gestational age (P = .045); higher prevalence of sepsis (P < .001); older age at audiologic examination (P < .001); more episodes of hypocapnia (P = .045); higher prevalence of inhaled nitric oxide use (P = .005); longer mechanical ventilation (P = .009); and longer aminoglycosides (P = .006), furosemide (P = .004), and pancuronium bromide (P = .001) treatments. On logistic regression analysis, the only variable independently associated with the development of SNHL was patient's age at audiologic follow-up (P = .012). CONCLUSIONS: Several risk factors were associated with SNHL development at univariate analysis. After logistic regression, only age at evaluation remained independently associated with SNHL. Routine audiologic follow-up is advocated in all CDH patients. Further studies are needed to define if other (genetic) factors may be involved in the pathogenesis of SNHL in patients with CDH.

Spectrum of MMACHC mutations in Italian and Portuguese patients with combined methylmalonic aciduria and homocystinuria, cblC type.

Methylmalonic aciduria (MMA) and homocystinuria, cblC type (MIM 277400) is the most frequent inborn error of vitamin B(12). The recent identification of the disease gene, MMACHC, has permitted preliminary genotype-phenotype correlations. We studied 24 Italian and 17 Portuguese patients with cblC defect to illustrate the spectrum of mutations in a southern European population and discuss the impact that mutation identification has on routine diagnostic procedures. Since the metabolic defect raises the serum levels of homocysteine, we also tested if variants in MTHFR-playing a key role in homocysteine remethylation pathway-could act as genetic modifier in cblC defect. We found that the c.271dupA (accounting for 55% of the MMACH alleles in our cohort) followed by c.394C>T (16%) and c.331C>T (9%) were the most frequent mutations. In our study we also identified a novel mutation (c.544T>C). On the other hand, the MTHFR genotype did not appear to influence age at onset, the clinical phenotype and outcome of patients with cblC defect. This study shows that mutation screening for the most common MMACH mutations occurring in early-onset forms (c.271dupA and c.331C>T) seems to have a high diagnostic yield in a southern European population with cblC defect. Although the identification of the gene defect per se does not predict completely time and severity of disease appearance, our data corroborate the importance of a molecular testing to offer accurate prenatal diagnosis to couples at high risk of having affected children.

High titer of autoantibodies to GAD identifies a specific phenotype of adult-onset autoimmune diabetes.

OBJECTIVE: The aim of the present study was to define heterogeneity of adult-onset autoimmune diabetes based on characterization of GAD antibodies (GADAs). RESEARCH DESIGN AND METHODS: Patients enrolled in a nationwide survey, the Non Insulin Requiring Autoimmune Diabetes (NIRAD) Study, have been screened for GADAs and IA-2 antibodies (IA-2As) and further characterized for GADA titer, antibodies to thyroid peroxidase (TPO), and HLA DRB1-DQB1 polymorphisms. RESULTS: Of 4,250 consecutive type 2 diabetic patients, 4.5% had either GADAs and/or IA-2As. Patients with autoimmune diabetes showed a clinical phenotype significantly different from that of type 2 diabetes, including higher fasting glucose and A1C, lower BMI and uric acid, lower prevalence of metabolic syndrome and its components, and higher frequency of TPO antibodies. More interestingly, analysis of GADA titers showed a bimodal distribution that identified two subgroups of patients with high (>32 GADA arbitrary units) and low (< or =32 GADA arbitrary units) GADA titers. Compared with those with low GADA titers, patients with high GADA titers had more prominent traits of insulin deficiency and a profile of more severe autoimmunity resulting in higher A1C, lower BMI, a lower prevalence of metabolic syndrome and its components (P < 0.02 for all), a higher prevalence of IA-2As, TPO antibodies (P < 0.003 for both), and DRB1*03-DQB1*0201 (50 vs. 26.8%, P = 0.001), and a decreasing frequency of DQB1*0602 and DRB1*0403 (from type 2 to low and to high GADA titer autoimmune diabetes; P < 0.001 for trend for both comparisons). CONCLUSIONS: GADA titers identify two subgroups of patients with adult-onset autoimmune diabetes having distinct clinical, autoimmune, and genetic features.

Importin beta: a novel autoantigen in human autoimmunity identified by screening random peptide libraries on phage.

By screening random peptide libraries (RPLs) with sera of Type 1 diabetes (T1D) patients, we previously identified 5 disease-specific 'mimotopes' displayed on phages (phagotopes). We already characterised 1 phagotope (CH1p), as an epitope of human osteopontin, an autoantigen expressed within the somatostatin cells of human islets. In this paper, we report the characterization of the second phagotope, 195Dyn, by immunohistochemistry, Western Blotting and screening of a human islet cDNA library using rabbit anti-195Dyn antibodies. The 195Dyn mimotope was detected in human islets. The screening of a lambdagt11 cDNA library from human islets has identified a clone, which corresponded to human importin beta. ELISA detected autoantibodies against this protein in sera of around 60% of TD1 patients and in 30% of patients affected by other autoimmune diseases. In summary, RPLs technology proved again successful in identifying another novel autoantigen (importin beta), whose significance in the autoimmune process remains to be fully elucidated.

HLA class II typing in newborns reveals a low frequency of the DRB1*04 allele and a high frequency of DRB1*11 allele in three regions of continental Italy.

As part of a longitudinal study aimed at defining the natural history of prediabetic autoimmunity and predicting the risk of future cases of type 1 diabetes, 3607 newborns from three regions of continental Italy (Lombardia, Liguria, and Lazio) were subjected to genetic testing to determine human leukocyte antigen-DRB1 (HLA-DRB1) and -DQB1 allele and phenotype frequencies. Polymerase chain reaction and immobilized sequence-specific oligonucleotide probe assays were used to identify ten DRB1 allele lineages and three DQB1 alleles. No major inter-regional differences emerged in the allelic distribution indicating homogeneous distribution of the HLA DRB1-DQB1 alleles among the three regions analyzed. Comparison of our data with those published for other Caucasian populations reveals that these three regions are characterized by a very low frequency of DRB1*04 (8%) and a high frequency of DRB1*11 (25%). The phenotype frequencies of HLA-DQB1*0302 and DQB1*0602 observed are also lower than those reported for other populations. Furthermore, the DRB1*04-DQB1*0302 haplotype was relatively infrequent in our population (5.3% of the newborns tested). These findings furnish a genetic "portrait" of the populations of the analyzed regions that will be useful not only for investigation of the genetic risk of type 1 diabetes mellitus in Italy but also for studies of other autoimmune diseases related to HLA genotypes.