Combined RNAscope and immunohistochemistry staining on duodenal paraffin sections as a new tool to reveal cytolytic potential of intraepithelial lymphocytes

: Immunohistochemistry (IHC) is a consolidated technique for the identification of surface and cytoplasmic antigens in cells or tissue sections using specific antibodies, yet simultaneous detection of two markers on the same cell may be difficult to achieve. Here we develop a protocol to perform a double staining using RNAscope, a new in-situ hybridization (ISH) technology, to visualize perforin transcripts, and classical IHC to visualize either CD8 or TcRγδ positive intraepithelial lymphocytes (IELs) in small intestinal paraffin sections of celiac disease (CD) patients. This double assay will allow to investigate the cytotoxic properties of two subsets of IELs in different stages of CD, thus contributing to understand the events leading to tissue destruction and healing

Butyrate modulating effects on pro-inflammatory pathways in human intestinal epithelial cells

Butyrate acts as energy source for intestinal epithelial cells and as key mediator of several immune processes, modulating gene expression mainly through histone deacetylation inhibition. Thanks to these effects, butyrate has been proposed for the treatment of many intestinal diseases. Aim of this study was to investigate the effect of butyrate on the expression of a large series of target genes encoding proteins involved in pro-inflammatory pathways. We performed quantitative real-time-PCR analysis of the expression of 86 genes encoding proteins bearing to pro-inflammatory pathways, before and after butyrate exposure, in primary epithelial cells derived from human small intestine and colon. Butyrate significantly down-regulated the expression of genes involved in inflammatory response, among which nuclear factor kappa beta, interferon-gamma, Toll like 2 receptor and tumour necrosis factor-alpha. Further confirmations of these data, including studies at protein level, would support the use of butyrate as effective therapeutic strategy in intestinal inflammatory disorders

Extra-Intestinal Manifestations of Coeliac Disease in Children: Clinical Features and Mechanisms

Celiac disease (CD) is a systemic autoimmune disease due to a dysregulated mucosal immune response to gluten and related prolamines in genetically predisposed individuals. It is a common disorder affecting ~1% of the general population, its incidence is steadily increasing. Changes in the clinical presentation have become evident since the 80s with the recognition of extra-intestinal symptoms like short stature, iron deficiency anemia, altered bone metabolism, elevation of liver enzymes, neurological problems. Recent studies have shown that the overall prevalence of extra-intestinal manifestations is similar between pediatric and adult population; however, the prevalence of specific manifestations and rate of improvement differ in the two age groups. For instance, clinical response in children occurs much faster than in adults. Moreover, an early diagnosis is decisive for a better prognosis. The pathogenesis of extra-intestinal manifestations has not been fully elucidated yet. Two main mechanisms have been advanced: the first related to the malabsorption consequent to mucosal damage, the latter associated with a sustained autoimmune response. Importantly, since extra-intestinal manifestations dominate the clinical presentation of over half of patients, a careful case-finding strategy, together with a more liberal use of serological tools, is crucial to improve the detection rate of CD

Short wheat challenge is a reproducible in-vivo assay to detect immune response to gluten.

It has been reported that interferon (IFN)-γ-secreting T cells reactive to gluten can be detected in the peripheral blood of individuals with treated coeliac disease (CD) after a short consumption of wheat-containing food. By contrast, very little is known about the reproducibility of this in-vivo procedure in the same patient cohort which underwent two, or more, gluten consumptions. Fourteen coeliac patients in remission consumed wheat bread for 3 days; 13 underwent a second gluten challenge after a wash-out of 3-10 months on a strict gluten-free diet. Immune reactivity to gluten was analysed in peripheral blood by detecting IFN-γ before and 6 days after commencing a gluten diet. Gliadin-specific IFN-γ-secreting CD4(+) T cells increased significantly on day 6 of the first challenge. These cells resulted as prevalently human leucocyte antigen (HLA)-DQ restricted and with a phenotype of gut homing, as suggested by the expression of β7-integrin. Similarly, reactiveness to gliadin was observed after the second wheat consumption, although with an individual variability of responses at each challenge. Our findings confirmed that the short wheat challenge is a non-invasive approach to investigate the gluten-related immune response in peripheral blood of subjects intolerant to gluten. Furthermore, we demonstrated that the in-vivo procedure can be reproduced in the same subject cohort after a gluten wash-out of at least 3 months. Our study has important implications for the application of this procedure to clinical practice

Tolerance to a new free amino acid-based formula in children with IgE or non-IgE-mediated cow's milk allergy: a randomized controlled clinical trial.

BACKGROUND: Amino acid-based formulas (Aaf) are increasingly used in children with cow's milk allergy (CMA). To be labeled hypoallergenic these formulas must demonstrate in clinical studies that they don't provoke reactions in 90% of subjects with confirmed CMA with 95% confidence when given in prospective randomized, double-blind, placebo-controlled challenge (DBPCFC) trials. The majority of available safety data on Aaf derived from patients with IgE-mediated CMA. Considering substantial differences in the immunologic mechanism and clinical presentation of non-IgE-mediated CMA it's important to investigate the hypoallergenicity of these formulas also in these patients. We prospectively assessed the tolerance to a new commercially available Aaf in children affected by IgE- or non-IgE-mediated CMA. METHODS:Consecutive patients affected by IgE- or non-IgE-mediated CMA, aged ≤ 4 years, were enrolled. DBPCFC was carried out with increasing doses of the new Aaf (Sineall, Humana, Milan, Italy), using validated Aaf as placebo. Faecal concentrations of calprotectin (FC) and eosinophilic cationic protein (ECP) were monitored. RESULTS:Sixty patients (44 male, 73.3%, median age 37, 95%CI 34.5-39.6 months, IgE-mediated CMA 29, 48.3%) were enrolled. At the diagnosis clinical symptoms were gastrointestinal (46.6%), cutaneous (36.6%), respiratory (23.3%), and systemic (10.0%). After DBPCFC with the new Aaf, no patient presented early or delayed clinical reactions. Faecal concentration of calprotectin and of ECP remained stable after the exposure to the new Aaf. CONCLUSIONS:The new Aaf is well tolerated in children with IgE- or non-IgE-mediated CMA, and it could be used as a safe dietotherapy regimen for children with this condition. TRIAL REGISTRATION:The trial was registered in the ClinicalTrials.gov Protocol Registration System (ID number: NCT01622426)

Tolerance to a new free amino acid-based formula in children with IgE or non-IgE-mediated cow's milk allergy: a randomized controlled clinical trial.

BACKGROUND: Amino acid-based formulas (Aaf) are increasingly used in children with cow's milk allergy (CMA). To be labeled hypoallergenic these formulas must demonstrate in clinical studies that they don't provoke reactions in 90% of subjects with confirmed CMA with 95% confidence when given in prospective randomized, double-blind, placebo-controlled challenge (DBPCFC) trials. The majority of available safety data on Aaf derived from patients with IgE-mediated CMA. Considering substantial differences in the immunologic mechanism and clinical presentation of non-IgE-mediated CMA it's important to investigate the hypoallergenicity of these formulas also in these patients. We prospectively assessed the tolerance to a new commercially available Aaf in children affected by IgE- or non-IgE-mediated CMA. METHODS:Consecutive patients affected by IgE- or non-IgE-mediated CMA, aged ≤ 4 years, were enrolled. DBPCFC was carried out with increasing doses of the new Aaf (Sineall, Humana, Milan, Italy), using validated Aaf as placebo. Faecal concentrations of calprotectin (FC) and eosinophilic cationic protein (ECP) were monitored. RESULTS:Sixty patients (44 male, 73.3%, median age 37, 95%CI 34.5-39.6 months, IgE-mediated CMA 29, 48.3%) were enrolled. At the diagnosis clinical symptoms were gastrointestinal (46.6%), cutaneous (36.6%), respiratory (23.3%), and systemic (10.0%). After DBPCFC with the new Aaf, no patient presented early or delayed clinical reactions. Faecal concentration of calprotectin and of ECP remained stable after the exposure to the new Aaf. CONCLUSIONS:The new Aaf is well tolerated in children with IgE- or non-IgE-mediated CMA, and it could be used as a safe dietotherapy regimen for children with this condition. TRIAL REGISTRATION:The trial was registered in the ClinicalTrials.gov Protocol Registration System (ID number: NCT01622426)

Diagnosing and Treating Food Allergy

t Food allergy (FA) is defined as an abnormal immunological reaction to food proteins. Over 90 % of FAs in childhood are caused by eight foods: cow’s milk, hen’s egg, soy, peanuts, tree nuts, wheat, fish and shellfish. The diagnostic work up for a child with suspected FA includes detailed medical history, physical examination, FA screening tests and response to elimination diet and to oral food challenge. Sometimes additional diagnostic tools to explore intestinal damage and function could be adopted. Currently, the only treatment for FA relies on strict elimination diets supervised by the nutritionist. Main new therapeutic strategies for FA include allergen-specific (oral, sublingual, epicutaneous, subcutaneous immunotherapy and heat treatment of food) and nonallergen-specific therapies (humanized monoclonal antibodies, anti-IgE and anti-IL5, probiotics). An incorrect diagnosis is likely to result in unnecessary dietary restrictions, which, if prolonged, may adversely affect the child’s nutritional status and growt

Potential Celiac Patients: A Model of Celiac Disease Pathogenesis

BACKGROUND AND AIM: Potential celiacs have the 'celiac type' HLA, positive anti-transglutaminase antibodies but no damage at small intestinal mucosa. Only a minority of them develops mucosal lesion. More than 40 genes were associated to Celiac Disease (CD) but we still do not know how those pathways transform a genetically predisposed individual into an affected person. The aim of the study is to explore the genetic features of Potential CD individuals. METHODS: 127 'potential' CD patients entered the study because of positive anti-tissue transglutaminase and no mucosal lesions; about 30% of those followed for four years become frankly celiac. They were genotyped for 13 polymorphisms of 'candidate genes' and compared to controls and celiacs. Moreover, 60 biopsy specimens were used for expression studies. RESULTS: Potential CD bear a lighter HLA-related risk, compared to celiac (??(2)???=???48.42; p value???=???1×10(-8)). They share most of the polymorphisms of the celiacs, but the frequency of c-REL* G allele was suggestive for a difference compared to celiac (??(2)???=???5.42; p value???=???0.02). One marker of the KIAA1109/IL-2/IL-21 candidate region differentiated potentials from celiac (rs4374642: ??2???=???7.17, p value???=???0.01). The expression of IL-21 was completely suppressed in potentials compared to celiacs (p value???=???0.02) and to controls (p value???=???0.02), in contrast IL-2, KIAA1109 and c-REL expression were over-expressed. CONCLUSIONS: Potential CD show genetic features slightly different from celiacs. Genetic and expression markers help to differentiate this condition. Potential CD is a precious biological model of the pathways leading to the small intestinal mucosal damage in genetically predisposed individuals