HLA genotyping in children with celiac disease allows to establish the risk of developing type 1 diabetes.

BACKGROUND AND AIMS: Celiac Disease (CD) and Type 1 Diabetes (T1D) often co-occur and share genetic components in the HLA class II region. We aimed to study the usefulness of HLA genotyping in predicting the risk of developing T1D in patients with CD and the temporal relationship between these diseases. METHODS: A cohort of 1,886 Sardinian patients, including 822 with CD, 1,064 with T1D, and 627 controls, underwent HLA class II typing. Seventy-six out of 822 CD patients were also affected by T1D (CD-T1D), and their HLA genotypes were analyzed for specific HLA associations with CD, T1D and controls. RESULTS: High-risk HLA-DQ genotypes, including HLA-DQ2.5/DQ8, -DQ2.5/DQ2.5, and -DQ2.5/DQ2.3, were strongly associated with CD-T1D with frequencies of 34.5%, 15.9%, and 18.8%, respectively. Conversely, certain HLA genotypes associated with CD appeared to confer protection against T1D development. Therefore, HLA genotyping allows the identification of those CD patients that might develop T1D. The frequency of patients with CD preceding T1D is higher in younger children than older ones, with implications for the early childhood approach to diabetes prevention. CONCLUSIONS: CD is a condition for future T1D development, and specific HLA genotypes can predict this risk. Early screening for celiac autoimmunity and subsequent HLA typing in CD children could help identify those at high risk for T1D, allowing for proactive interventions and immunotherapies to preserve beta-cell function. These findings may support the re-evaluation of HLA typing in children with CD.

Peripheral blood mononuclear cells reactivity in recent-onset type I diabetes patients is directed against the leader peptide of preproinsulin, GAD65271-285 and GAD65431-450.

Introduction: T cell reactivity against pancreatic autoantigens is considered one of the main contributors to the destruction of insulin-producing cells in type 1 diabetes (T1D). Over the years, peptide epitopes derived from these autoantigens have been described in NOD mice and in both HLA class II transgenic mice and humans. However, which ones are involved in the early onset or in the progressive phases of the disease is still unclear. Methods: In this work we have investigated, in early-onset T1D pediatric patients and HLA-matched controls from Sardinia, the potential of preproinsulin (PPI) and glutamate decarboxylase 65 (GAD65)-derived peptides to induce spontaneous T cell proliferation responses of peripheral blood mononuclear cells (PBMCs). Results: Significant T cell responses against PPI1-18, PPI7-19 and PPI31-49, the first two belonging to the leader sequence of PPI, and GAD65271-285 and GAD65431-450, were found in HLA-DR4, -DQ8 and -DR3, -DQ2 T1D children. Conclusions: These data show that cryptic epitopes from the leader sequence of the PPI and GAD65271-285 and GAD65431-450 peptides might be among the critical antigenic epitopes eliciting the primary autoreactive responses in the early phases of the disease. These results may have implications in the design of immunogenic PPI and GAD65 peptides for peptide-based immunotherapy.

Toward the renal vesicle: Ultrastructural investigation of the cap mesenchyme splitting process in the developing kidney.

Background: A complex sequence of morphogenetic events leads to the development of the adult mouse kidney. In the present study, we investigated the morphological events that characterize the early stages of the mesenchymal-to-epithelial transition of cap mesenchymal cells, analyzing in depth the relationship between cap mesenchymal induction and ureteric bud (UB) branching. Design and methods: Normal kidneys of newborn non-obese diabetic (NOD) mice were excised and prepared for light and electron microscopic examination. Results: Nephrogenesis was evident in the outer portion of the renal cortex of all examined samples. This process was mainly due to the interaction of two primordial derivatives, the ureteric bud and the metanephric mesenchyme. Early renal developmental stages were initially characterized by the formation of a continuous layer of condensed mesenchymal cells around the tips of the ureteric buds. These caps of mesenchymal cells affected the epithelial cells of the underlying ureteric bud, possibly inducing their growth and branching. Conclusions: The present study provides morphological evidence of the reciprocal induction between the ureteric bud and the metanephric mesenchyme showing that the ureteric buds convert mesenchyme to epithelium that in turn stimulates the growth and the branching of the ureteric bud.

Antibodies targeting the European lobster (Palinurus elephas) vitellogenin developed by mRNA isolation and in-silico-designed antigenic peptides.

Vitellogenin is an essential protein involved in ovary maturation in many animals. Detection of this protein correlated with reproductive capacity may be important if carried out on marine organisms such as the red spiny lobster Palinurus elephas, a crustacean that is an economically important crop from wild fish catches. Moreover, in recent years, vitellogenin has assumed an important role as a possible biomarker of marine environmental pollution, as its expression levels can be influenced by the presence of similar estrogen pollutants and can affect the reproductive sphere of marine organisms such as crustaceans. The P. elephas vitellogenin protein and its coding gene have never been isolated, so there is little information about its presence in this lobster. The aim of the present study was to develop a molecular strategy to create, for the first time, an antibody for the detection and quantization of vitellogenin in P. elephas.

Low-Risk Human Leukocyte Antigen Genes and Mild Villous Atrophy Typify Celiac Disease With Immunoglobulin A Deficiency.

OBJECTIVES: We aimed to establish if in celiac disease (CD) with immunoglobulin A deficiency (IgAD) duodenal histopathology is influenced by human leukocyte antigen (HLA)-DQB1∗02 alleles dosage. Clinical differences between patients with CD and patients with CD and IgAD (CD-IgAD) were also evaluated. METHODS: Five hundred and sixteen CD and 16 patients with CD-IgAD, enrolled over the time of 8 years, took part in this study. The severity of duodenal histopathology and frequency of CD at-risk HLA class II genes were compared in patients with CD versus patients with CD-IgAD. HLA class II genotypes were subdivided into two categories of genetic risk: high: HLA-DR3/DR7, -DR3/DR3, -DR4/DR4 -DR3/DR4 and low: HLA-DR5/DR7, -DR3/X, -DR4/X and X/X, where X means neither -DR3 nor -DR4. Then, they were compared with two types of duodenal histopathology: 0, 1, 2 and 3a of mild villous atrophy (MVA) and 3b and 3c of severe villous atrophy (SVA) according to the Marsh-Oberhuber classification. Clinical data concerning gender, number of esophagogastroduodenoscopies (EGDs) and association with other autoimmune diseases were obtained from medical records. RESULTS: In comparison with CD, CD-IgAD showed an increased frequency of MVA (P < 0.0001). Furthermore, CD-IgAD with MVA showed an increase of HLA low-risk genotypes (P = 0.036) and half HLA-DQ2 heterodimers (P = 0.0443). Interestingly, CD-IgAD demanded an increased number of EGDs to reach the diagnosis of CD (P = 0.0104) and autoimmune liver diseases were more frequent compared to CD (P = 0.0049). CONCLUSIONS: CD-IgAD is associated with MVA, low-risk HLA class II genes, an increased number of EGDs and autoimmune liver diseases.

Anti-actin IgA antibodies identify celiac disease patients with a Marsh 3 intestinal damage among subjects with moderate anti-TG2 levels.

A new diagnostic tool (algorithm-1) for coeliac disease (CD) permitting the diagnosis without performing the duodenal biopsy has been recently proposed by the European Society for Paediatric Gastroenterology, Hepatology, and Nutrition (ESPGHAN). It combines symptoms associated with CD, high anti-transglutaminase type 2 antibody (anti-TG2) levels, anti-endomysium-IgA antibodies (EMA), and at-risk HLA. Our aims were (i) to evaluate retrospectively in 227 individuals (149 CD patients and 78 controls) the algorithm-1, (ii) to reduce the number of duodenal biopsies among CD patients for whom algorithm-1 is not applicable through the addition of antiactin IgA antibodies (AAA-IgA), and (iii) to evaluate prospectively algorithm-1 and AAA-IgA in 50 patients with suspected CD. Algorithm-1 identified 70 out of 149 CD patients with Marsh 3 lesions. Adding AAA-IgA to the remaining patients with anti-TG2 levels comprised between 4 and 10 times upper limit of normal (ULN) allowed the detection of further 20 patients with a Marsh 3 damage. In our prospective study, algorithm-1 identified 23 out of 50 patients, whilst further 7 were recognized adding AAA-IgA. We confirm that algorithm-1 may avoid the duodenal biopsy in many CD patients and underscores the usefulness of AAA-IgA in reducing the number of duodenal biopsies in patients with moderate anti-TG2 levels.

High frequency of low-risk human leukocyte antigen class II genotypes in latent celiac disease.

Human leukocyte antigen (HLA) class II genotypes in latent celiac disease, a clinical variant of celiac disease (CD) have been scarcely studied. The aim of this work was to investigate whether latent CD and CD share similar frequencies of HLA class II genotypes. HLA class II genotypes of CD patients compared with controls were subdivided in the following at-risk groups: DQB1*02/DQB1*02 (43.0%, odds ratio [OR] 8.02, p < 0.0001), DQB1*0302/DQB1*02 (12.2%, OR 2.77, p = 0.0002), DQB1*02/DQB1*X (39.2%, OR 1.23, p = 0.1903), DQB1*0302/DQB1*X (3.4%, OR 0.35, p = 0.0064) and DQB1*X/DQB1*X (0.8%, OR 0.01, p = 0.0001) where X is neither DQB1*0302 nor DQB1*02. Next, HLA class II genotypes of 21 latent CD patients were compared with the above at-risk groups. Only one latent CD patient (4.8%) was found in the high risk DQB1*02/DQB1*02 group, three (14.3%) were DQB1*0302/DQB1*02, one (4.8%) was DQB1*0302/DQB1*X and the remaining 16 (76.2%) showed the DQB1*02/DQB1*X genotype. Noteworthy, the only 1 patient with the DQB1*02/DQB1*02 high risk genotype did not carry the DR3-DQB1*02/DR3-DQB1*02 or the DR3-DQB1*02/DR7-DQB1*02 but the uncommon DR3-DQB1*02/DR4-DQB1*02 genotype. These data suggest that latent CD is prevalently associated with low-risk HLA class II genotypes.

Turner syndrome mosaicism: an unusual case with a de novo large dicentric marker chromosome: mos 45,X/46,X, ter rea(X;X)(p22.3;p22.3).

X/X translocations are quite rare in humans. The effect of this anomaly on the phenotype is variable and depends on the amount of deleted material and whether the chromosomes are joined by their long or short arms. We report an unusual case of Turner syndrome mosaicism in a 16-year-old girl, who was referred to our Institute for primary amenorrhoea associated with short stature. Endocrine evaluation revealed hypergonadotropic hypogonadism, which required a study of the karyotype. Cytogenetic analysis, performed on peripheral blood leucocytes, showed a mos 45,X/46,X,ter rea (X;X)(p22.3;p22.3) de novo karyotype. The prevalent cell line was 45,X (90% cells). A second cell line (10% cells) showed a very large marker chromosome, similar to a large metacentric chromosome. FISH (fluorescent in situ hybridisation) and molecular analysis revealed that the marker chromosome was dicentric and totally derived from the paternal X chromosome.

Decline of lactase activity and c/t-13910 variant in Sardinian childhood.

OBJECTIVES: Our study aims to determine the age of onset of adult-type hypolactasia in Sardinians, and to establish the age at which genotyping of the C/T-13910 variant can be used reliably in the diagnosis of lactose malabsorption. PATIENTS AND METHODS: A lactose breath hydrogen test was given to 383 randomly selected patients, from 3 to 19 years old. RESULTS: The C/C-13910 genotype was found in 90% of patients; the frequency of the positive lactose breath hydrogen test increased with age and reached a prevalence of 85% at 9 years. CONCLUSIONS: In Sardinians, adult-type hypolactasia becomes phenotypically evident in all individuals older than 9 years, suggesting that this should be considered the minimum age at which the genetic test for lactase nonpersistence should be applied.

Prenatal diagnosis of a mosaic supernumerary marker iso (8p) (tetrasomy 8p): discordance between chorionic villi culture and amniotic fluid karyotypes.

We describe the first case of mosaic supernumerary marker iso (8p) displaying a karyotype discordance between chorionic villi (CV) and amniotic fluid (AF) cultures during prenatal cytogenetic diagnosis. In the first trimester, cytogenetic analysis after chorionic villi sampling (CVS) was normal in all metaphases in the short-term cytotrophoblast cell culture, but an undefined supernumerary marker was detected in 60% of mesenchymal cells in the long-term CV culture. Informed of the mosaicism, the couple selected amniotic fluid sampling as a second-trimester confirmatory diagnostic procedure. The supernumerary marker was absent in all of the 25 available AF cells metaphases. The prospective parents received genetic counselling and were informed that the discordance could be interpreted as a placental confined mosaicism or as a true foetal mosaicism with low percentage of affected cells. The couple opted to continue the pregnancy. In the second month of life, the child had abnormal development with severe psychomotor delay and frequent episodes of epilepsy. Postnatal cytogenetic extensive re-evaluation discovered that the previously detected supernumerary marker was indeed an isochromosome (8p) rearrangement present at low frequency in 5% of the blood lymphocytes.