Upregulated eotaxin expression and T cell infiltration in the basal and papillary epithelium in cows' milk associated reflux oesophagitis

Lymphocytic esophagitis: Still an enigma a decade later

Lymphocytic esophagitis (LE) is a clinicopathologic entity first described by Rubio et al in 2006. It is defined as peripapillary intraepithelial lymphocytosis with spongiosis and few or no granulocytes on esophageal biopsy. This definition is not widely accepted and the number of lymphocytes needed to make the diagnosis varied in different studies. Multiple studies have described potential clinical associations and risk factors for LE, such as old age, female gender and smoking history. This entity was reported in inflammatory bowel disease in the pediatric population but not in adults. Other associations include gastroesophageal reflux disease and primary esophageal motility disorders. The most common symptom is dysphagia, with a normal appearing esophagus on endoscopy, though esophageal rings, webs, nodularities, furrows and strictures have been described. Multiple treatment modalities have been used such as proton pump inhibitors and topical steroids. Esophageal dilation seems to be therapeutic when dysphagia is present along with esophageal narrowing secondary to webs, rings or strictures. The natural history of the disease remains unclear and needs to be better delineated. Overall, lymphocytic esophagitis seems to have a chronic and benign course, except for two cases of esophageal perforation in the literature, thought to be secondary to this entity.

Clinical spectrum of food allergies: a comprehensive review

Food allergy is defined as an adverse immune response towards food proteins or as a form of a food intolerance associated with a hypersensitive immune response. It should also be reproducible by a double-blind placebo-controlled food challenge. Many reported that food reactions are not allergic but are intolerances. Food allergy often presents to clinicians as a symptom complex. This review focuses on the clinical spectrum and manifestations of various forms of food allergies. According to clinical presentations and allergy testing, there are three types of food allergy: IgE mediated, mixed (IgE/Non-IgE), and non-IgE mediated (cellular, delayed type hypersensitivity). Recent advances in food allergy in early childhood have highlighted increasing recognition of a spectrum of delayed-onset non-IgE-mediated manifestation of food allergy. Common presentations of food allergy in infancy including atopic eczema, infantile colic, and gastroesophageal reflux. These clinical observations are frequently associated with food hypersensitivity and respond to dietary elimination. Non-IgE-mediated food allergy includes a wide range of diseases, from atopic dermatitis to food protein-induced enterocolitis and from eosinophilic esophagitis to celiac disease. The most common food allergies in children include milk, egg, soy, wheat, peanut, treenut, fish, and shellfish. Milk and egg allergies are usually outgrown, but peanut and treenut allergy tends to persist. The prevalence of food allergy in infancy is increasing and may affect up to 15-20 % of infants. The alarming rate of increase calls for a public health approach in the prevention and treatment of food allergy in children.

BSACI guideline for the diagnosis and management of cow's milk allergy

This guideline advises on the management of patients with cow's milk allergy. Cow's milk allergy presents in the first year of life with estimated population prevalence between 2% and 3%. The clinical manifestations of cow's milk allergy are very variable in type and severity making it the most difficult food allergy to diagnose. A careful age- and disease-specific history with relevant allergy tests including detection of milk-specific IgE (by skin prick test or serum assay), diagnostic elimination diet, and oral challenge will aid in diagnosis in most cases. Treatment is advice on cow's milk avoidance and suitable substitute milks. Cow's milk allergy often resolves. Reintroduction can be achieved by the graded exposure, either at home or supervised in hospital depending on severity, using a milk ladder. Where cow's milk allergy persists, novel treatment options may include oral tolerance induction, although most authors do not currently recommend it for routine clinical practice. Cow's milk allergy must be distinguished from primary lactose intolerance. This guideline was prepared by the Standards of Care Committee (SOCC) of the British Society for Allergy and Clinical Immunology (BSACI) and is intended for clinicians in secondary and tertiary care. The recommendations are evidence based, but where evidence is lacking the panel of experts in the committee reached consensus. Grades of recommendation are shown throughout. The document encompasses epidemiology, natural history, clinical presentations, diagnosis, and treatment.

Management guidelines of eosinophilic esophagitis in childhood

OBJECTIVES

Eosinophilic esophagitis (EoE) represents a chronic, immune/antigen-mediated esophageal disease characterized clinically by symptoms related to esophageal dysfunction and histologically by eosinophil-predominant inflammation. With few exceptions, 15 eosinophils per high-power field (peak value) in ≥1 biopsy specimens are considered a minimum threshold for a diagnosis of EoE. The disease is restricted to the esophagus, and other causes of esophageal eosinophilia should be excluded, specifically proton pump inhibitor-responsive esophageal eosinophilia. This position paper aims at providing practical guidelines for the management of children and adolescents with EoE.

METHODS

Relevant literature from searches of PubMed, CINAHL, and recent guidelines was reviewed. In the absence of an evidence base, recommendations reflect the expert opinion of the authors. Final consensus was obtained during 3 face-to-face meetings of the Gastroenterology Committee and 1 teleconference.

RESULTS

The cornerstone of treatment is an elimination diet (targeted or empiric elimination diet, amino acid-based formula) and/or swallowed, topical corticosteroids. Systemic corticosteroids are reserved for severe symptoms requiring rapid relief or where other treatments have failed. Esophageal dilatation is an option in children with EoE who have esophageal stenosis unresponsive to drug therapy. Maintenance treatment may be required in case of frequent relapse, although an optimal regimen still needs to be determined.

CONCLUSIONS

EoE is a chronic, relapsing inflammatory disease with largely unquantified long-term consequences. Investigations and treatment are tailored to the individual and must not create more morbidity for the patient and family than the disease itself. Better maintenance treatment as well as biomarkers for assessing treatment response and predicting long-term complications is urgently needed.

Potential for improving therapy and defining new research targets in eosinophilic oesophagitis based on understanding of immunopathogenesis

OBJECTIVES

This review considers the potential for therapeutic advances in the management of eosinophilic oesophagitis (EoE) based on recently increased understanding of the pathophysiology of the disorder.

METHODS

This is a review of publications characterising mucosal changes and leucocyte recruitment patterns in human and experimental EoE.

RESULTS

EoE, although diagnosed by epithelial infiltration of eosinophils, is actually a transmural inflammation in which eosinophil recruitment occurs via the deeper layers. Penetration of eosinophils into the epithelium is variable, explaining the need for multiple biopsies to diagnose what may be a clearly visible disorder. Fibrosis and neuromuscular dysfunction both occur within the subepithelial tissues. Recent murine studies have identified that T-cell recruitment underpins antigen-specific oesophageal eosinophil recruitment. Involvement of innate immunity is also suggested by the role of invariant natural killer T cells in experimental EoE.

CONCLUSIONS

Looking beyond present therapeutic options with a view to future studies, we identify T cells as candidates for "upstream therapy" if antigen specificity or homing markers are determined. Evidence of aeroallergen sensitisation suggests the possibility of lymphocyte priming within nasal-associated lymphoid tissue or Waldeyer ring, with the potential for topical therapy. We consider acquired neuromuscular dysfunction as a therapeutic target in acute symptomatic deterioration or bolus obstruction. We assess possible similarities with therapeutic stratagems for chronic asthma, recognising at the same time the anatomic specificity of the oesophagus and the difficulty in delivering effective topical medication to subepithelial tissues in this location compared with the airway.

Allergic gastrointestinal motility disorders in infancy and early childhood

Gastro-oesophageal reflux disease, constipation and colic are among the most common disorders in infancy and early childhood. In at least a subset of infants with these functional disorders, improvement after dietary elimination of specific food proteins has been demonstrated. Gastrointestinal food allergy should therefore be considered in the differential diagnosis of infants presenting with persistent regurgitation, constipation or irritable behaviour, particularly if conventional treatment has not been beneficial. The diagnosis of food protein-induced gastrointestinal motility disorders is hampered by the absence of specific clinical features or useful laboratory markers. Gastrointestinal biopsies before commencing a hypoallergenic diet may provide the most important diagnostic clues. Early recognition is essential for the optimal management of these patients to prevent nutritional sequelae or aversive feeding behaviours. Treatment relies on hypoallergenic formulae, as well as maternal elimination diets in breast-fed infants. Further research is required to better define the pathological mechanisms and diagnostic markers of paediatric allergic gastrointestinal motility disorders. The following article will present three instructive cases followed by discussion of the clinical presentation, diagnosis, treatment and natural history of food allergic motility disorders in infancy and early childhood.

Eosinophilic oesophagitis: epidemiology, clinical aspects, and association to allergy

Eosinophilic oesophagitis is characterised by age-dependent symptoms mimicking gastrooesophageal reflux disease, a distinct endoscopic appearance and a histological picture with extensive infiltration of eosinophils in the oesophageal mucosa. Eosinophilic oesophagitis is more frequently seen in males, and patients often belong to the paediatric or adolescence age groups. The exact prevalence of eosinophilic oesophagitis is unknown, but it has been suggested that the United States has a higher prevalence than Europe. Several treatment algorithms have been suggested, including elemental diets, oral steroids, inhaled (swallowed) steroids, and leucotriene receptor antagonists. Detailed information on the eosinophilic inflammatory processes in the oesophageal mucosa was initially obtained from animal models, in particular with regard to the role of interleukin-5 and the chemokine eotaxin-1 in eosinophilic recruitment. Studies have suggested a cytotoxic effect of eosinophilic degranulation products on nerve fibers in the gastric/intestinal mucosa, implicating a direct effect of allergic inflammation on gastrointestinal motility. Human studies recently have emphasized the role of eotaxin-3 and identified a single nucleotide polymorphism probably related to disease susceptibility.

Thoughts on the complex relationship between gastroesophageal reflux disease and eosinophilic esophagitis

Recent data suggest that the interaction between gastroesophageal reflux disease (GERD) and eosinophilic esophagitis can be complex, and that the notion of establishing a clear distinction between the two disorders may be too simplistic. There are at least four situations in which GERD might be associated with esophageal eosinophils: (a) GERD causes esophageal injury that results in a mild eosinophilic infiltration, (b) GERD and eosinophilic esophagitis coexist but are unrelated, (c) eosinophilic esophagitis contributes to or causes GERD, or (d) GERD contributes to or causes eosinophilic esophagitis. The high frequency of GERD described in adult patients with eosinophilic esophagitis suggests that there may be more than a chance association between the two disorders. This report discusses potential mechanisms for the complex interaction between GERD and eosinophilic esophagitis. We hope that this information will serve as a conceptual basis for future studies on the relationship between the two disorders. Whereas there are a number of plausible mechanisms whereby GERD might contribute to the accumulation of eosinophils in the esophageal epithelium, it seems prudent to recommend a clinical trial of proton pump inhibitor (PPI) therapy even when the diagnosis of eosinophilic esophagitis seems clear-cut. Furthermore, we suggest that a favorable response to PPI therapy does not preclude a diagnosis of eosinophilic esophagitis.

Recent advances in eosinophil biology

Eosinophils are pleiotropic multi-functional leukocytes involved in initiation and propagation of diverse inflammatory responses. Recent studies examining eosinophil biology have focused on delineating the molecular basis of FIP1L1/PDGRFalpha-fusion gene induced HES, the molecular steps involved in eosinophil recruitment in tumor-associated eosinophilia and EGID, and the role of eosinophils in asthma. In this review, these studies are summarized, focusing on the implications of these findings in the understanding the role of eosinophils in diseases.

Gastroesophageal reflux disease, colic and constipation in infants with food allergy

PURPOSE OF REVIEW

This review assesses the role of food allergy in the pathophysiology of gastroesophageal reflux disease, colic and constipation in infancy.

RECENT FINDINGS

Frequent regurgitation, persistent crying and constipation are common clinical problems in infancy. A subgroup of infants with these conditions may respond to hypoallergenic diets, but only few randomized clinical trials have been conducted. Skin prick testing and food-specific antibody levels are usually not elevated in these infants, whereas atopy patch testing may diagnostic. The mechanisms by which cow's milk and other food allergens induce gastrointestinal motility disorders are not understood. Apart from cell-mediated reactions, non-immunological effects of food constituents on gastrointestinal motility and gut microbiota may be involved in the pathogenesis. In the absence of reliable diagnostic tests, dietary elimination and re-challenge are usually required to confirm food allergy. A trial of amino acid-based formula or an oligoantigenic maternal elimination diet may be indicated in infants who have failed conventional medical treatment.

SUMMARY

Food allergy may contribute to gastroesophageal reflux disease, colic or constipation in infancy. Infants with these conditions often respond to hypoallergenic formula or a maternal elimination diet. Further research is needed to define the mechanisms and clinical markers of gastrointestinal food allergy in infancy.

Eosinophilia in the upper gastrointestinal tract is not a characteristic feature in cow's milk sensitive gastro-oesophageal reflux disease. Measurement by two methodologies

BACKGROUND

An association between cow's milk hypersensitivity (CMH) and gastro-oesophageal reflux disease (GERD) in childhood has been reported in the past decade.

AIM

To assess whether biopsies from the upper gastrointestinal tract of children with cow's milk sensitive GERD have a specific allergic inflammatory pattern, and to compare two different techniques for measuring inflammatory cells in gastrointestinal biopsies.

METHODS

GERD was diagnosed by means of endoscopy and oesophageal pH monitoring. Hypersensitivity to cow's milk was determined by an elimination diet and cow's milk challenge. Allergic inflammatory cells in upper gastrointestinal biopsies were identified by immunohistochemistry and their numbers were assessed by two different methods-counting the number of cells/high power field and using the computerised Cast-Grid system.

RESULTS

Cow's milk sensitive GERD was identified in 10 of 17 children with severe GERD (median age, 7.8 years). Biopsies from children with endoscopic oesophagitis had significantly increased numbers of mast cells and T cells. No differences in the number of eosinophils, mast cells, or T cells were found between children with CMH and those with primary GERD. Several differences were found between the two different histological quantification methods.

CONCLUSIONS

CMH was found not only in infants but also in school age children with GERD. Histology did not identify the cow's milk sensitive GERD subgroup. The computerised histological method provides a more complete evaluation based upon total biopsy area, and helped to limit the bias of uneven biopsy size.

An eye witness perspective of the changing patterns of food allergy

Food allergy may affect the gastrointestinal tract of children and adults too, albeit less commonly. The changing clinico-pathological expression of such food allergy in children over a 30 year period is related, from the eye witness perspective of a paediatric gastroenterologist in London. Tissue diagnosis by biopsy, related to dietary elimination and challenge has been the basis for the first clinico-pathological descriptions and accurate clinical diagnosis of these syndromes as they affect the gastrointestinal tract. In the 1970s cow's milk sensitive enteropathy presenting as chronic diarrhoea and failure to thrive in infancy often after infective gastroenteritis, especially with enteropathogenic Escherichia coli, was an important problem. By the late 1990s such presentations had become most uncommon in developed communities but they continue to occur in developing communities. By contrast in more recent times, multiple food allergy associated with minor small intestinal enteropathy and gastro-oesophageal reflux in older children has become an important clinical problem in children seen in developed communities. Accompanying these changes has been a dramatic fall in the number of children with clinically severe gastroenteritis with severe dehydration requiring hospital admission. Furthermore, the widespread diagnostic use of endoscopy of the upper and lower gastrointestinal tract in children with multiple biopsies has expanded gastroenterological diagnosis in children. This approach gives information about the oesophagus and ileo-colon not available in the earlier studies, which largely concentrated upon small intestinal biopsies, obtained by Crosby capsule biopsy. So, over this 30 year period clinico-pathological expression has altered but also the diagnostic approach has technically changed.

Review article: The eosinophil as a therapeutic target in gastrointestinal disease

Elevated levels of eosinophils in the gastrointestinal tract is a common feature of numerous gastrointestinal disorders including food allergy, parasitic infections, gastro-oesophageal reflux, eosinophilic oesophagitis, eosinophilic gastroenteritis, allergic colitis and inflammatory bowel diseases. Recently, clinical and experimental studies have provided evidence that eosinophils have a critical role in the pathophysiology of eosinophil-associated gastrointestinal disease. Collectively, these studies have provided relevant insight into identifying key targets for therapeutic intervention. The present review describes recent experimental investigations on the role of eosinophils in the clinical manifestations of eosinophil-associated gastrointestinal disease and discusses future therapeutic approaches for the treatment of disease.

Severe gastroesophageal reflux disease and cow milk hypersensitivity in infants and children: disease association and evaluation of a new challenge procedure

BACKGROUND

Gastroesophageal reflux disease (GERD) and cow milk hypersensitivity are frequent disorders of infancy. A possible causative association between these two entities has been suggested.

OBJECTIVE

The primary aim was to elucidate whether a causative relationship between the two entities could be established in a population of infants and children. A secondary aim was to evaluate whether cow milk challenge during esophageal pH monitoring is useful as an objective method to identify this subgroup of patients.

METHODS

Upper endoscopy followed by a 48-hour esophageal pH monitoring with cow's milk elimination diet at day 1 and challenge at day 2. Cow milk hypersensitivity was later verified by elimination diet and a second open (in patients < 3 years of age) or double-blind placebo-controlled (in patients > or = 3 years of age) challenge. Skin prick test, specific serum immunoglobulin E and skin patch test were used as supplementary procedures. Follow-up endoscopy and pH monitoring were performed after 3 months of treatment (omeprazole versus elimination diet dependent on evidence of food hypersensitivity).

RESULTS

Eighteen of 42 investigated patients had severe GERD, defined as endoscopic esophagitis and/or a reflux index > 10%. Among these patients, a group of 10 patients with GERD and cow milk hypersensitivity was identified. This group had a significantly higher reflux index compared with children with primary GERD. No significant increase was noted in reflux index during simultaneous pH monitoring and milk challenge.

CONCLUSIONS

An association between GERD and cow milk hypersensitivity was observed in both infants and children with severe GERD. Simultaneous cow milk challenge and pH monitoring had limited value as a method to identify this subgroup.

Chemokines in eosinophil-associated gastrointestinal disorders

Eosinophil-associated gastrointestinal disorders (EGDs) are characterized by a pronounced cellular inflammation. Recent clinical and experimental investigations have implicated a family of molecules known as chemokines in the regulation of leukocyte recruitment in these diseases. The underlying cellular and molecular mechanisms involved in chemokine-mediated cellular infiltration are largely unknown. In this review, we describe the role of CD4+ T cells and eosinophils in the clinical manifestations of EGDs and discuss the current understanding of the role of chemokines in the recruitment of these cells in the expression of diseases.

Low reproducibility of 2 x 24-hour continuous esophageal pH monitoring in infants and children: a limiting factor for interventional studies

The aim of this study was to investigate the day-to-day reproducibility of 24-hr esophageal pH monitoring. The procedure was performed continuously for 48 hr in order to enable future studies on dietary challenges, using consecutive 2 x 24 hr pH recording. Furthermore, one objective was to relate the degree of reproducibility to endoscopic evidence of mucosal injury. Upper endoscopy and 2 x 24-hr consecutive pH monitoring were performed in 30 infants and children referred for gastroesophageal reflux disease. The monitoring was performed without dietary or activity restrictions in order to assess reflux parameters in a near-normal physiologic setting. The NASPGHAN criteria for pathological reflux index (RI, % fraction of time with pH < 4.0) were employed. Based upon the NASPGHAN criteria for the RI, 9/30 subjects (30%) had discordant (normal vs pathologic) results at the two recording days, yielding an overall reproducibility of 70%. The limits of agreement for RI at day 2 were 0.2-3.3 times the initially obtained value at day 1. No difference was found in terms of reproducibility between groups with and without esophageal mucosal changes (erythema and esophagitis). No significant difference was noted in the association between pH monitoring and macroscopic esophageal mucosal changes between the two recordings days. In conclusion, a considerable intraindividual variability in reflux parameters was observed between the measurements from day 1 to day 2. This physiologic variability should be taken into consideration when evaluating gastroesophageal reflux disease in infants and children by means of pH monitoring. The day-to-day variability limits the use of simultaneous pH monitoring and dietary challenges as a procedure to identify a possible causative relation between GERD and dietary allergy/intolerance.

Cow's milk allergy: a new understanding from immunology

BACKGROUND

Because of the high prevalence of cow's milk allergy as one of the most frequent clinical presentations of food allergy in infancy and early childhood, it is important to define the condition accurately. Allergy must be distinguished from the broader term food intolerance, which may be defined as a reproducible adverse reaction to the ingestion of a food or to any of its components, ie, proteins, carbohydrates, fats, and additives, and which includes toxic, metabolic, and allergic reactions. By contrast, food allergy may be defined as an adverse clinical reaction to a specific food component and that is immunologically mediated. The rapid increase in knowledge resulting from research in immunology in recent years has not only led to a better understanding of the basis for cow's milk allergy in infancy, but has also yielded considerable promise for improved diagnosis and management of the condition.

OBJECTIVE

To review recent developments in immunology which demonstrate how they may lead to a better understanding of the clinical spectrum of cow's milk allergy in infants and children.

DATA SOURCES

English language articles were selected from PubMed and selected abstracts that would have immediate, practical clinical implications. The review focuses on themes related to gastro-enterology, focusing upon the esophagus and small intestine.

RESULTS

In cow's milk-sensitive esophagitis, there is dense infiltrate of eosinophils and increased T cell activation with upregulation of the chemokine eotaxin. In cow's milk-sensitive enteropathy, there is T cell activation, and it often results as a sequela of gastro-enteritis. Changing patterns in recent years suggests that sensitization occurs via mother's breastmilk to cow's milk and multiple food antigens. There is evidence of reduced Th1 response in these children. This is related to associated IgA deficiency and low levels of cytokine transforming growth factor beta.

CONCLUSIONS

The results of the present review demonstrate that the clinical manifestations of cow's milk allergy are very diverse, with differences between developing and developed countries. Understanding the immunologic mechanisms is of key importance in understanding this diversity.