Francesco Prisco

Zonulin Upregulation Is Associated With Increased Gut Permeability in Subjects With Type 1 Diabetes and Their Relatives

Zonulin, a protein that modulates intestinal permeability, is upregulated in several autoimmune diseases and is involved in the pathogenesis of autoimmune diabetes in the BB/Wor animal model of the disease. To verify the association between serum zonulin levels and in vivo intestinal permeability in patients with type 1 diabetes, both parameters were investigated in different stages of the autoimmune process. Forty-two percent (141 of 339) of the patients had abnormal serum zonulin levels, as compared with age-matched control subjects. The increased zonulin levels correlated with increased intestinal permeability in vivo and changes in claudin-1, claudin-2, and myosin IXB genes expression, while no changes were detected in ZO1 and occludin genes expression. When tested in serum samples collected during the pre–type 1 diabetes phase, elevated serum zonulin was detected in 70% of subjects and preceded by 3.5 ± 0.9 years the onset of the disease in those patients who went on to develop type 1 diabetes. Combined, these results suggest that zonulin upregulation is associated with increased intestinal permeability in a subgroup of type 1 diabetic patients. Zonulin upregulation seems to precede the onset of the disease, providing a possible link between increased intestinal permeability, environmental exposure to non–self antigens, and the development of autoimmunity in genetically susceptible individuals.

Celiac disease in children and adolescents with type I diabetes: importance of hypoglycemia.

Background Symptomatic hypoglycemia is an unavoidable problem in the treatment of type I diabetes. Celiac disease is associated with malabsorption and may therefore represent an important risk factor. Methods The frequency of symptomatic hypoglycemia in patients with type I diabetes and celiac disease (cases) was compared with those of patients who had diabetes without celiac disease (controls). For this purpose, each case was matched for age, sex, and duration of disease with one to two control patients. Indices of metabolic control (hemoglobin [Hb]A1c, frequency of hypoglycemia, and total insulin requirement) were retrieved for the 18 months before and after diagnosis of celiac disease. Results Eighteen patients (6 males and 12 females) had diagnosed celiac disease and were matched with 26 control patients (10 males and 16 females). There was no difference in age (11.0 years; range, 1.8–21.9 vs. 13.1 years; range, 2.3–22;P = 0.3) and duration of disease (8.4 years; range, 1.2–19.3 vs. 8.3 years; range, 1.1–18.7;P = 0.3) between the two groups. During the 6 months before and after diagnosis of celiac disease the cases had significantly more hypoglycemic episodes than the controls (means ± SD; 4.5 ± 4 vs. 2.0 ± 2.2 episodes/months, P = 0.01). This was reflected by a progressive reduction in insulin requirement over the 12 months before diagnosis reaching a nadir at time 0 (0.6 ± 0.2 vs. 0.9 ± 0.3, P = 0.05). Conclusion These data suggest that underlying celiac disease is associated with an increased risk of symptomatic hypoglycemia and that the introduction of a gluten-free diet with normalization of the intestinal mucosa may reduce its frequency.

Sulfonylurea treatment outweighs insulin therapy in short-term metabolic control of patients with permanent neonatal diabetes mellitus due to activating mutations of the KCNJ11 (KIR6.2) gene

To the Editor, Activating missense mutations in the gene encoding potassium inwardly rectifying channel, subfamily J, member 11 (KCNJ11) represent the most common cause (40 to 64%, depending on populations) of permanent neonatal diabetes mellitus in patients diagnosed in the first 6 months of life [1, 2]. In addition, KCNJ11 activating mutations can lead to transient/relapsing neonatal diabetes [3, 4]. The KCNJ11 gene encodes the pore-forming subunit (also known as KIR6.2) of the pancreatic beta cell ATP-sensitive potassium channel (KATP), which exerts a pivotal role in glucose-regulated insulin release. In the beta cell, KIR6.2 forms a hetero-octameric complex (4:4) with the sulfonylurea receptor subtype 1 (SUR1); binding to SUR1 by sulfonylureas determines channel closure and insulin secretion [2]. In previously published cases, seven patients have been reported to respond well to the transfer from insulin to oral hypoglycaemic agents [4–8]. Here we report on the replacement of insulin with sulfonylureas in ten Italian children who have mutations in KCNJ11 (R50P, V59M [x4], K170R, R201C and R201H [x3]) and were followed in nine Diabetologia (2006) 49:2210–2213 DOI 10.1007/s00125-006-0329-x

Blood ketone bodies in patients with recent‐onset type 1 diabetes (a multicenter study)

Background:  Insulin deficiency with glucagon excess leads to the release of ketone bodies (KBs) by the liver and excretion in the urine. So far, only KB monitoring in urine has been used during assessment of children with diabetes. Currently used nitroprusside strips for urine KB detection react only with acetoacetate (AcAc) and not with the most prevalent KB moiety – 3β‐hydroxybutyrate (3HB) – that is in equilibrium with AcAc (up to 10:1 ratio).

Low-protein diet and progression of retinal degeneration in gyrate atrophy of the choroid and retina: A twenty-six-year follow-up

Summary: Gyrate atrophy of the choroid and retina is an autosomal recessive chorioretinal dystrophy which leads to a slowly progressive loss of vision. The primary defect is due to a deficiency of the enzyme ornithine δ-aminotransferase, which is responsible for markedly elevated levels of ornithine in plasma and other body fluids. Although several therapeutic regimens have been proposed, the reduction in ornithine accumulation obtained by reducing the intake of its precursor arginine (semisynthetic low-arginine diet) is the one most practised. In this clinical and molecular study we report a patient with hyperornithinaemia and gyrate atrophy of the choroid and retina who had been diagnosed when she was 3 years 9 months old. She also presented mild mental retardation, delayed language development and speech defects. The patient has recently been found to be homozygous for the new Gly91Arg amino acid substitution of the enzyme ornithine δ-aminotransferase. This mutation lies in a region of the mature protein that is considered crucial for the mitochondrial targeting activity. In this patient, a 28-year treatment with a completely natural low-protein diet (0.8 g/kg per day of natural protein) has been able to significantly reduce ornithine plasma levels, and to greatly delay the natural progression of the chorioretinal changes. This study suggests that, in the long-term treatment of gyrate atrophy, the efficacy in slowing the progression of chorioretinal changes and the palatability of a completely natural low-protein diet make this treatment a potentially viable alternative in patients refusing the semisynthetic diet.

Use of real time continuous glucose monitoring and intravenous insulin in type 1 diabetic mothers to prevent respiratory distress and hypoglycaemia in infants

BackgroundPregnancy in Type 1 diabetic patients is a precarious condition, both for mother and fetus with increased the risk of prematurity and, immediately after delivery with risk of respiratory distress syndrome and hypoglycaemia in newborns. A strict control and monitoring of diabetes throughout pregnancy is important in reducing the impact of the disease on the fetus and newborn. In recent years many new technologies have been introduced to ameliorate diabetes monitoring, where the last is the Real-time Continuous Glucose Monitoring System (RT-CGMS).MethodsIn the last three years, 72 h continuous glucose monitoring system (RT-CGMS) (Medtronic, CA) was performed in 18 pregnant women with Type 1 diabetes in two moments of pregnancy: during treatment with betamethasone to prevent respiratory distress and during delivery. In both cases insulin was administered intravenous and the dose was changed on the basis of glycaemia.ResultsThe results present the use of this new technique during two topics moments of pregnancy of type 1 diabetes patients when is very important intensively to monitor diabetes and to obtain the well being of the fetus. No infant experimented hypoglycaemia or respiratory distress syndrome at the moment and in the first hours after the birth.ConclusionWe wish to stress the importance reducing glycaemia during administration of betamethasone and during labor. It is conceivable that the scarce attention paid to monitoring glucose levels in diabetic mothers during labor in gynaecological world may be due to the difficulty in glucose monitoring with the devices until now available. Hopefully, our anecdotal account may prompt improvements with RT-CGMS, and may lead to a better approach to the problem, thereby changing the prognosis of infants born to diabetic mothers.

The influence of gluten free diet on quantitative ultrasound of proximal phalanxes in children and adolescents with type 1 diabetes mellitus and celiac disease

A reduced bone mineral density has been reported in patients with untreated celiac disease (CD) as well as in patients with poorly controlled type 1 diabetes mellitus (T1DM). The aim of this study was to evaluate the bone mineral status by phalangeal quantitative ultrasound in 52 children and adolescents with both diseases (mean age 13.3+/-4.9 years). As a control group 50 patients with T1DM and no CD (age 12.2+/-4.0 years) were studied. The following bone parameters, amplitude-dependent speed of sound (AD-SoS) and bone transmission time (BTT) were considered and expressed as z score. Compliance to gluten free diet and long term glycemic control (mean of four determinations of HbA1c in the last year) were also assessed. The lowest mean AD-SoS z score values were found in patients with T1DM and CD, who reported transgressions to gluten free diet and exhibited positivity for serum anti-tissue transglutaminase antibodies (tTG) and/or endomysial antibodies (EmA), compared with patients with occasional transgressions but negative for anti-tTG and/or -EmA, patients strictly adherent to the diet, and patients who suffered only from diabetes (ANOVA p=0.021). No difference was found between patients with diabetes alone and patients with both diseases strictly adherent to gluten free diet. Prevalence of osteopenia (z AD-SoS values <-2 SD) was higher in patients with T1DM and CD and poor compliance to the diet (45.5%) compared with patients with T1DM (8%) or patients with both diseases strictly compliant to diet (12.9%) (p=0.015). A negative correlation between Ad-SoS z score and HbA1c (r -0.236, p=0.036) was found when patients with T1DM and patients with T1DM and CD, who strictly adhere to the diet, were pooled. In conclusion the quality of bone as assessed by phalangeal ultrasound in patients with T1DM and CD, who strictly adhere to gluten free diet, is similar to that found in T1DM patients. A higher prevalence of osteopenia is present in patients with both diseases who reported habitual transgressions to gluten free diet. The gluten free diet, as well as the optimization of glycemic control, plays an important role in preventing the osteopenic status caused by the clustering of these two chronic diseases.

Potential celiac disease in type 1 diabetes: a multicenter study.

AIMS To describe the prevalence of potential celiac disease (pot-CD) in young patients with type 1 diabetes mellitus (T1DM) and characterize their clinical features. METHODS This cross-sectional multicenter study involved 8717 T1DM patients from 31 Italian centers. Information was collected on the total number of T1DM patients, CD patients and pot-CD patients. The following data were collected on pot-CD patients: gender, age at T1DM diagnosis, age at the first CD serological positivity, presence of CD-related symptoms, presence of other autoimmune disorders and treatment with gluten free diet (GFD). One thousand-three-hundred-sixty-one patients who were positive for CD serology were the control group. RESULTS CD serological positivity was found in 7.2% T1DM patients. Prevalence of pot-CD was 12.2% (n=77) among CD positive patients: symptoms were present in 12/77; a third autoimmune disorder was found in 15 patients. Prevalence of pot-CD in the control population was 8.4% (n=114; p=0.005). No difference was found with regard to clinical features. Only few symptomatic patients were on GFD both in T1DM and control patients. CONCLUSIONS A higher prevalence of pot-CD was found in T1DM patients, that may be ascribed to the routine screening, although the influence of genetic factors cannot be excluded.

Mitochondrial diabetes in children: seek and you will find it.

Maternally Inherited Diabetes and Deafness (MIDD) is a rare form of diabetes due to defects in mitochondrial DNA (mtDNA). 3243 A>G is the mutation most frequently associated with this condition, but other mtDNA variants have been linked with a diabetic phenotype suggestive of MIDD. From 1989 to 2009, we clinically diagnosed mitochondrial diabetes in 11 diabetic children. Diagnosis was based on the presence of one or more of the following criteria: 1) maculopathy; 2) hearing impairment; 3) maternal heritability of diabetes/impaired fasting glucose and/or hearing impairment and/or maculopathy in three consecutive generations (or in two generations if 2 or 3 members of a family were affected). We sequenced the mtDNA in the 11 probands, in their mothers and in 80 controls. We identified 33 diabetes-suspected mutations, 1/33 was 3243A>G. Most patients (91%) and their mothers had mutations in complex I and/or IV of the respiratory chain. We measured the activity of these two enzymes and found that they were less active in mutated patients and their mothers than in the healthy control pool. The prevalence of hearing loss (36% vs 75–98%) and macular dystrophy (54% vs 86%) was lower in our mitochondrial diabetic adolescents than reported in adults. Moreover, we found a hitherto unknown association between mitochondrial diabetes and celiac disease. In conclusion, mitochondrial diabetes should be considered a complex syndrome with several phenotypic variants. Moreover, deafness is not an essential component of the disease in children. The whole mtDNA should be screened because the 3243A>G variant is not as frequent in children as in adults. In fact, 91% of our patients were mutated in the complex I and/or IV genes. The enzymatic assay may be a useful tool with which to confirm the pathogenic significance of detected variants.

Bone involvement in clusters of autoimmune diseases: just a complication?

Bone loss, described in individual groups of patients with Type 1 diabetes (T1D), autoimmune thyroid disease (ATD) or celiac disease (CD) is usually viewed as a complication of these diseases. There is increasing evidence that alterations in the immune system may directly affect bone mass. Clustering of autoimmune diseases in the same individual might predispose to higher risk of osteopenia due to imbalance in immune regulation. The aim of this study was to evaluate bone involvement in clusters of the most common autoimmune diseases (T1D, ATD and CD) in children. The study was performed at a tertiary care center for the care of pediatric diabetes. One-hundred-two patients with T1D alone or associated with ATD and/or CD were studied; 13 patients had cluster of three autoimmune diseases. Amplitude-dependent speed of sound (AD-SoS) was measured by phalangeal quantitative ultrasound and expressed as standard deviation score (SDS). AD-SoS SDS < -2 was considered indicative of osteopenia. Osteopenia was equally distributed among children with T1D alone (8.1%), T1D associated with ATD (7.7%) or CD (10.3%), while it was 53.8% in patients presenting with three autoimmune diseases. Poor compliance to gluten-free diet increased osteopenia to 18.8% in patients with T1D and CD and 80% in patients with three autoimmune disorders. No difference among groups was found with regard to gluco-metabolic control, calcium metabolism, thyroid function. In conclusion bone impairment in multiple autoimmune diseases might be considered not only a complication due to endocrine or nutritional mechanisms, but also a consequence of an immunoregulatory imbalance. Alterations of homeostatic mechanisms might explain an imbalance of osteoclast activity leading to osteopenia.