Allergic enteritis in children

Extracellular adenosine triphosphate skews the T helper cell balance and enhances neutrophil activation in mice with food allergies

Exposure to food allergens elicits fast changes in the intestinal microenvironment, which guides the development of allergic reactions. Investigating the key information about these changes may help in better understanding food allergies. In this research, we explored the relationship between a food allergy and extracellular adenosine triphosphate (ATP), a danger molecule that has been proved to regulate the onset of allergic asthma and dermatitis but has not been studied in food allergies, by developing a unique animal model through allergen-containing diet feeding. After consuming an allergen-containing diet for 7 days, the allergic mice exhibited severe enteritis with elevated luminal ATP levels. The dysregulated luminal ATP worsened food-induced enteritis by enhancing Th17 cell responses and increasing mucosal neutrophil accumulation. In vitro experiments demonstrated that ATP intervention facilitated Th17 cell differentiation and neutrophil activation. In addition, the diet-induced allergy showed noticeable gut dysbiosis, characterized by decreased microbial diversity and increased diet-specific microbiota signatures. As the first, we show that food-induced enteritis is associated with an elevated concentration of luminal ATP. The dysregulated extracellular ATP exacerbated the enteritis of mice to a food challenge by manipulating intestinal Th17 cells and neutrophils.

Food protein-induced allergic proctocolitis in infants: Literature review and proposal of a management protocol

Food protein-induced allergic proctocolitis (FPIAP) is a condition characterized by inflammatory changes in the distal colon in response to one or more foreign food proteins because of immune-mediated reactions.

FPIAP prevalence estimates range widely from 0.16% in healthy children and 64% in patients with blood in stools.

In clinical practice, FPIAP is diagnosed when patients respond positively to the elimination of a suspected triggering food allergen. Nevertheless, significant proportions of infants get misdiagnosed with IgE mediated allergy and undergo unnecessary dietary changes.

Diagnosis is based on clinical symptoms, a good response to an allergen-free diet and the recurrence of symptoms during the “allergy challenge test”. Sometimes clinical features may be non-specific and the etiology of rectal bleeding in childhood may be heterogeneous. Therefore, it is crucial to exclude a variety of other possible causes of rectal bleeding in the pediatric age group, including infection, anal fissure, intestinal intussusception and, in infants, necrotizing enterocolitis and very early onset inflammatory bowel disease. The diagnostic workup includes in those cases invasive procedures such as sigmoidoscopy and colonoscopy with biopsies.

The high prevalence of FPIAP contrasts with the lack of known information about the pathogenesis of this condition. For this reason and due to the absence of a review of the evidence, a literature review appears necessary to clarify some aspects of allergic colitis.

The aim of the review is to fill this gap and to lay the foundations for a subsequent evidence-based approach to the condition.

CCR8 leads to eosinophil migration and regulates neutrophil migration in murine allergic enteritis

Allergic enteritis (AE) is a gastrointestinal form of food allergy. This study aimed to elucidate cellular and molecular mechanisms of AE using a murine model. To induce AE, BALB/c wild type (WT) mice received intraperitoneal sensitization with ovalbumin (an egg white allergen) plus ALUM and feeding an egg white (EW) diet. Microarray analysis showed enhanced gene expression of CC chemokine receptor (CCR) 8 and its ligand, chemokine CC motif ligand (CCL) 1 in the inflamed jejunum. Histological and FACS analysis showed that CCR8 knock out (KO) mice exhibited slightly less inflammatory features, reduced eosinophil accumulation but accelerated neutrophil accumulation in the jejunums, when compared to WT mice. The concentrations of an eosinophil chemoattractant CCL11 (eotaxin-1), but not of IL-5, were reduced in intestinal homogenates of CCR8KO mice, suggesting an indirect involvement of CCR8 in eosinophil accumulation in AE sites by inducing CCL11 expression. The potential of CCR8 antagonists to treat allergic asthma has been discussed. However, our results suggest that CCR8 blockade may promote neutrophil accumulation in the inflamed intestinal tissues, and not be a suitable therapeutic target for AE, despite the potential to reduce eosinophil accumulation. This study advances our knowledge to establish effective anti-inflammatory strategies in AE treatment.