Update on the Role of Allergy in Pediatric Functional Abdominal Pain Disorders: A Clinical Perspective

Both functional abdominal pain disorders (FAPDs) and food allergies are relatively common in children and adolescents, and most studies report an association between FAPDs and allergic conditions. FAPDs share pathophysiologic processes with allergies, including both immune and psychological processes interacting with the microbiome. No conclusive data are implicating IgE-mediated reactions to foods in FAPDs; however, there may be patients who have IgE reactions localized to the gastrointestinal mucosa without systemic symptoms that are not identified by common tests. In FAPDs, the data appears stronger for aeroallergens than for foods. It also remains possible that food antigens initiate an IgG reaction that promotes mast cell activation. If a food allergen is identified, the management involves eliminating the specific food from the diet. In the absence of systemic allergic symptoms or oral allergy syndrome, it appears unlikely that allergic triggers for FAPDs can be reliably identified by standard testing. Medications used to blunt allergic reactions or symptomatically treat allergic reactions may be useful in FAPDs. The purpose of the current manuscript is to review the current literature regarding the role of allergy in FAPDs from a clinical perspective, including how allergy may fit in the current model of FAPDs.

Protease Activated Receptor-2 Induces Immune Activation and Visceral Hypersensitivity in Post-infectious Irritable Bowel Syndrome Mice

BACKGROUND

The role of protease activated receptor-2 (PAR-2) in the pathogenesis of abdominal pain in irritable bowel syndrome (IBS) is not well defined.

AIMS

To investigate the role of PAR-2-mediated visceral hypersensitivity in a post-infectious IBS (PI-IBS) mouse model.

METHODS

T. spiralis-infected PI-IBS mouse model was used. Fecal serine protease activity and intestinal mast cells were evaluated. Intestinal permeability was assessed by urine lactulose/mannitol ratio, and colonic expressions of PAR-2 and tight junction (TJ) proteins were examined by Western blot. Intestinal immune profile was assessed by measuring Th (T helper) 1/Th2 cytokine expression. Visceral sensitivity was evaluated by abdominal withdrawal reflex in response to colorectal distention.

RESULTS

Colonic PAR-2 expression as well as fecal serine protease activity and intestinal mast cell counts were elevated in PI-IBS compared to the control mice. Decreased colonic TJ proteins expression, increased lactulose/mannitol ratio, elevated colonic Th1/Th2 cytokine ratio, and visceral hypersensitivity were observed in PI-IBS compared to the control mice. Administration of PAR-2 agonist in control mice demonstrated similar changes observed in PI-IBS mice, while PAR-2 antagonist normalized the increased intestinal permeability and reduced visceral hypersensitivity observed in PI-IBS mice.

CONCLUSIONS

PAR-2 activation increases intestinal permeability leading to immune activation and visceral hypersensitivity in PI-IBS mouse model.

Cow's Milk Protein Allergy in Infancy: A Risk Factor for Functional Gastrointestinal Disorders in Children?

The role and prevalence of cow's milk protein allergy (CMA) in functional gastrointestinal disorders remains unclear. The aim of this review is to update knowledge on the relationship between CMA and functional abdominal pain disorders (FAPDs) in children. Cochrane Database and Pubmed were searched from inception using general and specific terms for CMA and functional gastrointestinal disorders. CMA is reported as a predisposing or coexisting factor in a wide range of functional gastrointestinal disorders in infants and children. Pathogenesis of both conditions is complex and multiple mechanisms including dysmotility and hypersensitivity might contribute to the clinical manifestations. Data supporting the possible role of food allergies in the pathogenesis of FAPDs are limited. CMA may predispose to early life inflammation and visceral hypersensitivity, which in turn might manifest as FAPDs. The diagnosis of either CMA or FAPDs and distinction between them is challenging because of nonspecific and overlapping symptoms. Lack of accurate allergy tests in non-IgE (immunoglobulin E) mediated cases is also problematic. Oral food challenge, following an elimination diet, should be performed to diagnose a suspected non-IgE CMA allergy in children with FAPDs. In the management of FAPDs, an elimination diet should be considered for a limited period to verify if the symptoms improve or resolve.

New therapeutic perspectives in irritable bowel syndrome: Targeting low-grade inflammation, immuno-neuroendocrine axis, motility, secretion and beyond

Irritable bowel syndrome (IBS) is a chronic, recurring, and remitting functional disorder of the gastrointestinal tract characterized by abdominal pain, distention, and changes in bowel habits. Although there are several drugs for IBS, effective and approved treatments for one or more of the symptoms for various IBS subtypes are needed. Improved understanding of pathophysiological mechanisms such as the role of impaired bile acid metabolism, neurohormonal regulation, immune dysfunction, the epithelial barrier and the secretory properties of the gut has led to advancements in the treatment of IBS. With regards to therapies for restoring intestinal permeability, multiple studies with prebiotics and probiotics are ongoing, even if to date their efficacy has been limited. In parallel, much progress has been made in targeting low-grade inflammation, especially through the introduction of drugs such as mesalazine and rifaximin, even if a better knowledge of the mechanisms underlying the low-grade inflammation in IBS may allow the design of clinical trials that test the efficacy and safety of such drugs. This literature review aims to summarize the findings related to new and investigational therapeutic agents for IBS, most recently developed in preclinical as well as Phase 1 and Phase 2 clinical studies.

Can probiotics benefit children with autism spectrum disorders?

Children with autism are commonly affected by gastrointestinal problems such as abdominal pain, constipation and diarrhea. In recent years, there has been a growing interest in the use of probiotics in this population, as it hypothetically may help to improve bowel habits and the behavioral and social functioning of these individuals. The gut microbiome plays an important role in the pathophysiology of organic as well as functional gastrointestinal disorders. Microbial modification with the use of antibiotics, probiotics, and fecal transplantation have been effective in the treatment of conditions such as recurrent Clostridium difficile infection, pouchitis, and irritable bowel syndrome. The present review presents a number of reported clinical, immunological and microbiome-related changes seen in children with autism compared to normally developed children. It also discusses gut inflammation, permeability concerns, and absorption abnormalities that may contribute to these problems. Most importantly, it discusses evidence, from human and animal studies, of a potential role of probiotics in the treatment of gastrointestinal symptoms in children with autism.

Role of C-reactive Protein in Acute Appendicitis

Background Acute appendicitis is the common surgical emergency. This study analyzed the value of C-reactive protein as the diagnostic marker of acute appendicitis. Objective To assess the level of C-reactive protein in acute appendicitis and to relate the quantitative measurement with degree of inflammation of appendix. Method A cross sectional study was done with consecutive patients diagnosed with acute appendicitis that underwent appendectomy over six months period. Peroperative findings and histopathology report were compared and analyzed with the level of C-reactive protein. Result A total of 54 patients were enrolled in this study. 94.40% were proved as acute appendicitis in histopathology. The level of C-reactive protein was significantly raised among highly inflamed appendix. C-reactive protein showed 84.31% sensitivity, 66.66% specificity, 97.72% positive predictive value and 20% negative predictive value in diagnosing acute appendicitis. Conclusion With degree of inflammation of appendix, value of C-reactive protein was raised. Quantitative assessment can predict severity of inflammation. Raised level of C-reactive protein is an aid for diagnosing acute appendicitis.

Irritable bowel syndrome and visceral hypersensitivity : risk factors and pathophysiological mechanisms

Irritable bowel syndrome (IBS) is a common functional gastro-intestinal disorder, characterized by abdominal pain and altered intestinal motility. Visceral hypersensitivity is an important hallmark feature of IBS and is believed to underlie abdominal pain in patients with IBS. The two main risk factors associated with the development of IBS are gastrointestinal inflammation and psychological distress. On a peripheral level, visceral sensitivity seems to be modulated by several mechanisms. Immune cells in the mucosal wall, such as mast cells, and enterochromaffin cells may sensitize afferent nerves by release of their mediators. Furthermore, increased mucosal permeability, altered intestinal microflora and dietary habits may contribute to this feature. On a central level, an increased prevalence of psychiatric comorbidities is demonstrated in IBS patients, alongside alterations in the hormonal brain-gut axis, increased vigilance towards intestinal stimuli and functional and structural changes in the brain. The pathogenesis of IBS is complicated and multifactorial and the treatment remains clinically challenging. Dietary measures and symptomatic control are the cornerstones for IBS treatment and may be sufficient for patients experiencing mild symptoms, alongside education, reassurance and an effective therapeutic physician-patient relationship. New pharmacological therapies are aimed at interfering with mediator release and/or blockade of the relevant receptors within the gut wall, while modulation of the intestinal flora and diet may also be of therapeutic benefit. Tricyclic anti-depressants and serotonin reuptake inhibitors act both on a central and peripheral level by modulating pain signalling pathways.

MPV and other inflammatory markers in diagnosing acute appendicitis

OBJECTIVE

To investigate whether mean platelet volume can be used as an inflammatory marker for the diagnosis of acute appendicitis, and to determine the role, if any, of white blood cell count, C-reactive protein and neutrophil count in this regard.

METHODS

The retrospective study was conducted at Mersin University (MEU) Health Research and Application Center, Emergency Department, Mersin, Turkey, and included medical record of patients having gone appendectomy between April 2012 to July 2013. Based on pathology examination, the cases were grouped as uncomplicated, complicated, and non-appendicitis cases. Preoperative white blood cell, neutrophil, C-reactive protein and mean platelet volume were noted. SPSS 16 was used for statistical analysis.

RESULTS

Records of 275 patients were studied. Overall, 90(32.7%) patients were uncomplicated, 120(43.7%) complicated, and 65(23.6%) were non-appendicitis cases. The first two groups had a significantly higher white blood cell (p=0.001) and neutrophil (p<0.001) counts than the third one. Mean platelet volume levels were not statistically different (p=0.478).The neutrophil count had a sensitivity of 76.19%, specificity of 56.92%, positive predictive value of 85.11%, and negative predictive value of 42.53%; white blod cell count had sensitivity 68.10%, specificity 61.54%, positive predictive value 85.12%, and negative predictive value 37.38%; mean platelet volume level had sensitivity 74.76%, specificity 35.38%, positive predictive value 78.89%, and negative predictive value 30.26%; and C-reactive protein level had sensitivity 84.29%, specificity 30.77%, positive predictive value 79.73%, and negative predictive value 37.74%.

CONCLUSIONS

Elevated white blood cell and neutrophil counts may be used as diagnostic tests in cases of acute appendicitis, while C-reactive protein and mean platelet volume levels were not useful as diagnostic markers.

Mast cell activation syndrome: a newly recognized disorder with systemic clinical manifestations

BACKGROUND

Diagnostic criteria for mast cell (MC) activation syndrome have been recently proposed, but clinical studies to validate these criteria are lacking.

OBJECTIVE

We sought to determine the clinical manifestations of this newly recognized syndrome in a cohort of patients.

METHODS

We prospectively evaluated 18 patients seen at our institution with MC activation syndrome from 2006 to 2009. Patients enrolled had at least 4 of the signs and symptoms of abdominal pain, diarrhea, flushing, dermatographism, memory and concentration difficulties, or headache. Response to treatment with anti-MC mediator medications was assessed based on established criteria. Laboratory tests indicating MC mediator release and histopathology and immunohistochemical studies on gastrointestinal biopsy samples were performed.

RESULTS

Ninety-four percent of the patients had abdominal pain, 89% had dermatographism, 89% had flushing, and 72% had the constellation of all 3 symptoms. Patients additionally had headache, diarrhea, and memory and concentration difficulties. All patients had at least 1 positive laboratory test result for an increased MC mediator level. On the basis of the response to treatment criteria, 67% of the patients in the cohort had either a complete or major regression in symptoms while taking medications targeting MC mediators. There was no significant difference in the numbers of intestinal mucosal MCs between our patients and healthy control subjects.

CONCLUSION

MC activation syndrome might be the underlying cause of unexplained symptoms when several organ systems are involved, such as the gastrointestinal tract and the skin. It is especially important to be able to recognize the constellation of clinical features because response to anti-MC mediator medications is often excellent.

Pepper mild mottle virus, a plant virus associated with specific immune responses, Fever, abdominal pains, and pruritus in humans

BACKGROUND

Recently, metagenomic studies have identified viable Pepper mild mottle virus (PMMoV), a plant virus, in the stool of healthy subjects. However, its source and role as pathogen have not been determined.

METHODS AND FINDINGS

21 commercialized food products containing peppers, 357 stool samples from 304 adults and 208 stool samples from 137 children were tested for PMMoV using real-time PCR, sequencing, and electron microscopy. Anti-PMMoV IgM antibody testing was concurrently performed. A case-control study tested the association of biological and clinical symptoms with the presence of PMMoV in the stool. Twelve (57%) food products were positive for PMMoV RNA sequencing. Stool samples from twenty-two (7.2%) adults and one child (0.7%) were positive for PMMoV by real-time PCR. Positive cases were significantly more likely to have been sampled in Dermatology Units (p<10(-6)), to be seropositive for anti-PMMoV IgM antibodies (p = 0.026) and to be patients who exhibited fever, abdominal pains, and pruritus (p = 0.045, 0.038 and 0.046, respectively).

CONCLUSIONS

Our study identified a local source of PMMoV and linked the presence of PMMoV RNA in stool with a specific immune response and clinical symptoms. Although clinical symptoms may be imputable to another cofactor, including spicy food, our data suggest the possibility of a direct or indirect pathogenic role of plant viruses in humans.

[Peanut allergy]

Peanut allergy currently affects around 1% of the UK and US paediatric population and represents a major healthcare concern because it is outgrown in less than 20% of cases and is a major cause of anaphylaxis. Its main symptoms, triggered by peanut ingestion, are cutaneous (urticaria, erythema, angioedema), gastrointestinal (abdominal pain, vomiting, diarrhoea), respiratory (wheezing, dyspnoea) and cardiovascular (hypotension, arrhythmia, shock). The usual onset of symptoms occurs soon after peanut ingestion (minutes to hours); however some patients have biphasic reactions, with exacerbations occurring up to 8 hours later. Peanut allergy diagnostic is based mainly upon the medical history (preferably including a diet diary and elimination diets), skin testing, peanut-specific IgE measurement and ideally a peanut oral challenge. Peanut allergy management includes monitorisation and education for avoiding peanut-containing foods and for recognising and treating anaphylactic episodes (self-injectable adrenalin and rapid-acting antihistamines). In the past, anti-IgE antibodies were shown to decrease the risk of anaphylaxis by reducing the allergic patients' reactivity to peanuts. Recent investigations, driven by the need to develop efficient treatment and prevention strategies for peanut allergy, suggest that oral immunotherapy with peanuts, although exposing the patients to significant risk, may represent a promising therapeutic approach. Furthermore, contrary to the general view that peanut avoidance in infants could prevent peanut allergy, a recent study shows that the opposite may be true as early consumption of peanuts in infancy is associated with a low prevalence of peanut allergy.

Diagnostic value of Helicobacter pylori serologic test in pediatric population with abdominal pain

The aim of this study was to determine the diagnostic value of a serologic test for Helicobacter pylori (H. pylori) in pediatric population presenting with abdominal pain suspected of peptic disease. We conducted a preospective cross sectional study. There were 202 children with abdominal pain. Serologic BM test using Helisual Quick test kit was performed. All patients then underwent endoscopic examination. The calculated sensitivity, specificity, positive and negative predictive values of the applied serologic BM test were 72.4%, 64.8%, 44.6% and 85.7%, respectively. We concluded that a positive result from serologic test could not be judged independently. Thus, in symptomatic patients, other diagnostic methods (e.g. endoscopy and UBT) should be applied prior to the therapeutic decisions.

The clinical characteristics of Anisakis allergy in Korea

Anisakidae larvae can cause anisakiasis when ingested by humans. Although several groups have reported a gastrointestinal Anisakis allergy among people in Spain and Japan, our report is the first to summarize the clinical features of 10 Anisakis allergy cases in Korea. We enrolled 10 Korean patients (6 men and 4 women) who complained of aggravated allergic symptoms after ingesting raw fish or seafood. Sensitization to Anisakis was confirmed by detecting serum specific IgE to Anisakis simplex. The most common manifestation of anisakiasis was urticaria (100%), followed by abdominal pain (30%) and anaphylaxis (30%). All patients presenting with these symptoms also exhibited high serum specific IgE (0.45 to 100 kU/L) to A. simplex. Nine patients (90%) exhibited atopy and increased total serum IgE levels. The fish species suspected of carrying the Anisakis parasite were flatfish (40%), congers (40%), squid (30%), whelk (10%), and tuna (10%). Anisakis simplex should be considered as a possible causative food allergen in adult patients presenting with urticaria, angioedema, and anaphylaxis following the consumption of raw fish or seafood.

Pattern of interleukin-1beta secretion in response to lipopolysaccharide and ATP before and after interleukin-1 blockade in patients with CIAS1 mutations

OBJECTIVE

To examine the synthesis, processing, and secretion of interleukin-1beta (IL-1beta), as well as the clinical and biologic effects of IL-1 blockade, in patients with chronic infantile neurologic, cutaneous, articular (CINCA) syndrome and Muckle-Wells syndrome (MWS), in an effort to understand the molecular mechanisms linking mutations of the CIAS1 gene and IL-1beta hypersecretion, and the underlying response to IL-1 receptor antagonist (IL-1Ra).

METHODS

Six patients with CINCA syndrome or MWS were treated with IL-1Ra and followed up longitudinally. Monocytes obtained from the patients and from 24 healthy donors were activated with lipopolysaccharide (LPS) for 3 hours, and intracellular and secreted IL-1beta levels were determined by Western blotting and enzyme-linked immunosorbent assay before and after exposure to exogenous ATP.

RESULTS

LPS-induced IL-1beta secretion was markedly increased in monocytes from patients with CIAS1 mutations. However, unlike in healthy subjects, secretion of IL-1beta was not induced by exogenous ATP. Treatment with IL-1Ra resulted in a dramatic clinical improvement, which was paralleled by an early and strong down-regulation of LPS-induced IL-1beta secretion by the patients' cells in vitro.

CONCLUSION

Our results showed that the requirements of ATP stimulation for IL-1beta release observed in healthy individuals are bypassed in patients bearing CIAS1 mutations. This indicates that cryopyrin is the direct target of ATP and that the mutations release the protein from the requirement of ATP for activation. In addition, the dramatic amelioration induced by IL-1Ra treatment is at least partly due to the strong decrease in IL-1beta secretion that follows the first injections of the antagonist. These findings may have implications for other chronic inflammatory conditions characterized by increased IL-1beta.

Measurements of eosinophil activation before and after food challenges in adults with food hypersensitivity

BACKGROUND

Objective assessment of inflammatory reactions in the gastrointestinal tract could be useful in the diagnosis of food hypersensitivity. The aim of the present study was to investigate the involvement of eosinophils and mast cells in the inflammatory response of patients with food hypersensitivity before and after food challenges.

METHODS

Eleven patients (4 with IgE-mediated allergy and 7 without) with food hypersensitivity and positive double-blind, placebo-controlled food challenge were subjected to food challenge in a single-blinded fashion. Four subjects with no known food hypersensitivity were recruited as controls. Placebo was given after a 1-week washout period followed by an active dose. Stool, urinary and serum samples were collected and symptoms were recorded in a diary. Fecal samples were analyzed for eosinophil protein X (F-EPX) and tryptase; urinary samples for EPX (U-EPX) and leukotriene E4 (U-LTE4) and serum samples were analyzed for eotaxin and food-specific IgE antibodies.

RESULTS

Patients with IgE-mediated food allergy had increased levels of F-EPX compared to controls and tended to have lower serum levels of eotaxin compared to non-allergic patients and controls. U-LTE4 was significantly higher in allergic patients compared to non-allergic patients after challenge. Moreover, F-EPX correlated to U-LTE4 (p = 0.011). Reported symptoms, abdominal pain, distension, flatulence and nausea were similar in the allergic and non-allergic patients.

CONCLUSION

The results strongly indicate that eosinophils are activated in the gastrointestinal tract of food-allergic patients but not in patients with non-allergic food hypersensitivity. Due to the inconsistent pattern of symptoms after placebo and active food challenge, it was not possible to relate the levels of inflammation markers to the recorded symptoms.

Acute abdominal pain in systemic lupus erythematosus: focus on lupus enteritis (gastrointestinal vasculitis)

OBJECTIVE

To determine the causes of acute abdominal pain in systemic lupus erythematosus (SLE) and to compare the clinical and laboratory data, especially antiphospholipid antibodies and the SLE Disease Activity Index (SLEDAI), between lupus enteritis (gastrointestinal vasculitis) and acute abdominal pain without lupus enteritis in patients with SLE.

METHODS

A retrospective study was carried out for all patients admitted with SLE from 1993 to March 2001. The SLEDAI and laboratory data were collected at the time of diagnosis of SLE and at the time of acute abdominal pain. Lupus enteritis (gastrointestinal vasculitis) was diagnosed by clinical investigation and abdominal computed tomographic findings.

RESULTS

Chart review identified 175 patients (20 male, 155 female) who had been admitted with SLE. Of these patients, 38 (22%) presented with acute abdominal pain. Lupus enteritis was the most common cause of acute abdominal pain. Patients were divided into three groups: group 1: lupus enteritis (n=17), group 2: acute abdominal pain without lupus enteritis (n=21), and group 3: SLE without acute abdominal pain (n=137). There was no difference in age and sex among the three groups. Antiphospholipid, anti-RNP, anti-Sm, anti-Ro, and anti-La antibodies did not differ among the three groups. There was no difference in the SLEDAI at the time of diagnosis and at the time of acute abdominal pain between groups 1 and 2. Complement, erythrocyte sedimentation rate, C reactive protein, and anti-dsDNA measured at the time of acute abdominal pain did not differ between groups 1 and 2. A drop in the white blood cell count at the time of abdominal pain was more prominent in group 1 than group 2. In lupus enteritis, the jejunum and ileum were the sites most commonly affected. Rectal involvement was rare. Even though four patients relapsed, all the patients with lupus enteritis, including those who relapsed, responded well to corticosteroid.

CONCLUSION

Lupus enteritis is the most common cause of acute abdominal pain in SLE. All patients with lupus enteritis responded well to a high dose of a corticosteroid without surgical intervention. The SLEDAI and laboratory data, except leucopenia, do not correlate with the occurrence of lupus enteritis.

Recurrent abdominal pain, food allergy and endoscopy

Gastrointestinal food allergy, a well-recognized clinical entity, has a wide spectrum of clinical features, including cutaneous, respiratory and gastrointestinal symptoms and objective abnormalities. The gastrointestinal alterations in food allergy have been described throughout the gastrointestinal tract. Recurrent abdominal pain (RAP) is a common complaint in school-age children. The findings among children with RAP of an underlying food allergy associated with mucosal pathology of the foregut may support a causal relationship between food allergy and RAP. Further studies are needed to elucidate whether well-documented food allergy (based on double-blind placebo-controlled food challenges) is a major cause of RAP.

Mucosal pathology of the foregut associated with food allergy and recurrent abdominal pains in children

To determine whether children with recurrent abdominal pain (RAP) include an excess of children with food allergy (FA), this study examined a consecutive series of 84 children (43M, 41F, mean age 7.9 y, range 1.6-15 y) referred during 1 y to 2 university hospitals. In addition to a clinical examination, the patients underwent gastroduodenoscopy with three biopsy specimens, skin-prick and patch tests, and comprehensive laboratory tests for atopic allergy. Based on an open elimination-challenge test, a total of 28 (33%) subjects were diagnosed for FA. In the whole material, specific endoscopic abnormalities were found in 38 (45%) subjects: oesophagitis in 17, gastric erosions in 8, lymphonodular duodenitis in 12 and erosive duodenitis in 5. FA showed a close relationship with duodenal lesions, but no significant association with oesophagitis and gastritis. The histological findings were mild, although some alterations could be observed in up to 66 (79%) subjects, equally often in patients with and without FA. None showed villous atrophy or severe infiltration of eosinophilic or mononuclear cells. Slightly increased densities of eosinophilic cells were significantly associated with endoscopic findings, especially oesophagitis. At least one positive skin-prick test with food allergens was found in 11 subjects and a positive patch test in 21 subjects, but neither showed an association with the endoscopic or histological findings, or even with clinical FA.

CONCLUSION

Since the children with FA showed significantly more often concomitant mucosal pathology of the foregut than those without FA, FA may be considered one of the major factors underlying RAP. The report suggests the trial of an elimination diet in cases with RAP if lymphonodular hyperplasia or duodenitis is seen on gastroduodenoscopy.

Immunopathogenesis of human gastrointestinal infection by Anisakis simplex

BACKGROUND

Anisakis simplex is a parasite of fish, and in the case of human infestation, it should be considered as a possible cause of gastrointestinal disease, especially in countries where raw or undercooked fish is a frequent food. Clinical features of anisakiasis may simulate acute abdominal pain, such as that found in patients with gastric ulcers, appendicitis, and Crohn's disease. Furthermore, many cases of anisakiasis are diagnosed as eosinophilic gastroenteritis, which is a broad term for a specific disease.

OBJECTIVE

The purpose of this study was to investigate the immunopathogenesis of human gastrointestinal infestation by A simplex.

METHODS

Thirteen intestinal biopsy specimens from patients with anisakiasis were analyzed for the presence of messenger (m)RNA for different cytokines and inflammatory mediators by RT-PCR. Specific IgE, eosinophil cationic protein, eosinophil protein X, and tryptase levels were measured in each patient's serum. Also, cell cultures were set up with lymphocytes from some patients and stimulated in vitro with Anisakis and Ascaris antigens.

RESULTS

We performed immunologic phenotyping in 13 patients. All patients underwent biopsy after emergency surgery caused by episodes of acute abdominal pain. In all cases inflammatory infiltrate composed of eosinophils and lymphocytes was found in the intestinal wall. We demonstrated that after infestation, a T(H2)-type immune response occurred. Also, major basic protein, nitric oxide, and eotaxin were found in the tissue, and eosinophil cationic protein and eosinophil protein X levels were elevated in sera.

CONCLUSION

These data and in vitro lymphocyte cultures indicate that a T(H2) mechanism plays an important role in the inflammatory infiltrate produced by the anchorage of parasites in the gastrointestinal wall.

[Incidence of increased serum Helicobacter pylori IgG antibodies in children with and without chronic abdominal pain]

The prevalence of Helicobacter pylori (HP) IgG antibodies was analysed in a group of 142 asymptomatic children (group A) and in 31 pediatric patients (group B) with recurrent abdominal pain. HP IgG antibodies were measured by a commercially available fluorescence-enzyme immuno-assay test (Heloritest IgG, Fa Eurospital). In asymptomatic children the prevalence of HP IgG antibodies increased significantly with age from 17% with 6 years to more then 40% with 14 years. A higher prevalence of HP IgG antibodies was found in children living in more crowded housing conditions. Comparing the number of HP IgG positive children in group B (58%) to a matched population from group A (35%) no statistically different prevalence rates were found. Thus HP IgG antibodies are found in similar frequencies, in both, symptomatic and asymptomatic children. Therefore the presence of HP-IgG antibodies does not necessarily indicate that the HP infection is the cause for the recurrent abdominal pain in these children.

Salivary and gastric fluid secretory immunoglobulin A and free secretory component concentrations in children with Helicobacter pylori-positive gastritis

The concentrations of secretory IgA (sIgA) in the saliva and the concentrations of free secretory components (FSC) both in the saliva and gastric fluid of patients with Helicobacter pylori HP-positive gastritis and of a control group with functional recurrent abdominal pain (RAP) were measured in order to determine whether there is a deficiency of these non-specific local defence factors in children with HP infection. Eighteen patients with HP-positive gastritis and 12 children with RAP were included in the study and sIgA and FSC concentrations were analysed using the radial immunodiffusion technique. In contrast to our initial hypothesis, the concentrations of FSC in saliva and gastric fluid and sIgA in saliva of patients with HP infection showed no significant difference when compared with children who do not have an organic disease and HP infection. It is suggested that these local defence factors are not involved in the pathogenesis of HP-positive gastritis.

Antinuclear antibodies in children with chronic nonspecific complaints

Children who are chronically complaining nonspecific symptoms such as headache, fatigue, abdominal pain, and low grade fever are commonly seen in daily pediatric outpatient clinics. Some of them are unable to go to school and are diagnosed as school refusal by physicians or educational staff. On the other hand, there are children who do not fulfill any criteria of collagen diseases and whose anti-nuclear antibodies (ANA) are found to be positive. Some of these children have chronic nonspecific complaints. We prospectively studied the prevalence of ANA in children who visited a pediatric outpatient clinic because of chronic nonspecific complaints. Surprisingly, 74 out of 140 symptomatic children (52.4%) were positive for ANA, while only 5 out of 82 healthy control children (6.1%) were positive (p < 0.0001). 39 of 74 ANA positive patients (52.1%) have low ANA titers < or = 1:80, nevertheless 36 patients (47.9%) have high ANA titers > or = 1:160. ANA fluorescent patterns were homogeneous and speckled in 75.3%, speckled in 17.6% and others in 6.8%. ANA positive patients tended to have general fatigue and low grade fever, while gastrointestinal problems such as abdominal pain and diarrhea and orthostatic dysregulation symptoms were commonly seen in ANA negative patients. Children who were unable to go to school more than 1 day a week were seen significantly more in ANA positive patients than in negative patients. Autoantibody analysis using Western immunoblot revealed that 26 out of 63 ANA positive sera (41.3%) had antibodies to the 62 kD protein which had not been previously noticed. These data suggest that autoimmune mechanism may play a role in childhood chronic nonspecific symptoms. We therefore propose a new disease entity of the autoimmune fatigue syndrome in children. When chronically complaining children visit a pediatric out-patient clinic, immunological approaches should be considered before they are discriminated as school refusal or having psychogenic disorders.

Relation between Helicobacter pylori infection and gastrointestinal symptoms and syndromes

BACKGROUND

Helicobacter pylori is a human pathogen that colonises the gastric mucosa and causes permanent gastric inflammation.

AIMS

To assess the symptoms of H pylori infection in an adult unselected population.

SUBJECTS

A random sample of 3589 adult Danes who were examined in 1982 and 1987 (n = 2987).

METHODS

Abdominal symptoms within the preceding year were recorded at both attendances. Circulating IgG antibodies against H pylori in serum samples drawn in 1982 were measured by using in-house indirect enzyme linked immunosorbent assays (ELISA).

RESULTS

People with increased levels of IgG antibodies to H pylori were more likely than uninfected individuals to report heartburn (odds ratio (OR) = 1.26, 95% confidence interval (CI) 1.03-1.54) and abdominal pain characterised by daily length (OR = 1.33, 95% CI 0.92-1.91), nocturnal occurrence (OR = 1.62, 95% CI 1.19-2.19), spring aggravation (OR = 1.68, 95% CI 0.70-4.05), and no relation to meals (OR = 0.62, 95% CI 0.43-0.91) or stress (OR = 0.69, 95% CI 0.50-0.95). The inclusion of people with increased levels of IgG antibodies to H pylori, but without upper dyspepsia, at study entry significantly increased the likelihood of reporting upper dyspepsia at follow up (OR = 1.71, 95% CI 1.24-2.36). People with epigastric pain and increased levels of IgM antibodies to H pylori only indicative of acute H pylori infection were more likely to report nocturnal pain, heartburn, nausea, and vomiting.

CONCLUSION

H pylori infection may precede the development of dyspepsia and is associated with a variety of gastrointestinal symptoms in people with no history of peptic ulcer disease.

Helicobacter pylori and recurrent abdominal pain in children

Recurrent abdominal pain is one of the most common presentations to pediatricians; yet an organic etiology can be found in only 10% of cases. Because infection with Helicobacter pylori in adults and children results in gastritis, a causative role for the organism has been postulated. To investigate this theory, we conducted a prospective case-control study in children with recurrent abdominal pain using serum H. pylori IgG antibodies measured by an enzyme immunoabsorbent assay. Age, sex, ethnicity, and socioeconomic status were adjusted in the statistical model. Five subjects (5.1%) and 14 controls (14.3%) had raised serum IgG antibodies to H. pylori (adjusted OR, 0.21; 95% confidence interval, 0.05, 0.85). The negative association between H. pylori and recurrent abdominal pain indicates that this organism is unlikely to have an important etiologic role in this disorder.

Ranitidine administration in Henoch-Schönlein vasculitis

In this study, we discuss 12 patients with gastrointestinal (GI) bleeding who were diagnosed as having Henoch Schoenlein vasculitis (HSV) in Dr Behçet Uz Children's Hospital, Izmir, between January 1991 and January 1992. Seven male and five female patients were included in the study. Their ages ranged between 6-14 years. The patients were separated into two identical groups and were given ranitidine or a placebo. Both groups were followed up for abdominal pain and GI bleeding. In the group administered ranitidine the duration and severity of abdominal pain and gastrointestinal bleeding decreased significantly as compared to the group taking placebo (P < 0.05). No side effects of ranitidine were observed. As a result, it was concluded that ranitidine could be used to treat HSV with GI symptoms.

[Is recurrent abdominal pain in children a symptom of hyperreactivity disorder?]

Suggestions in the literature about a possible role of hypersensitivity in children with recurrent abdominal pain induced an open controlled investigation in twenty children with recurrent abdominal pain and in twenty healthy children. The purpose was to look for differences in the numbers of hypersensitivity markers in pain and control children. Hypersensitivity markers were defined in four areas: familial disposition to atopic disease, atopic disease in the child's history, atopic disease disclosed at a clinical examination, and elevated levels of blood eosinophils and serum immunoglobulin E antibodies to selected inhalant allergens and food allergens. In no child was abdominal pain provoked by specific food intake. The total number of markers in the pain children was 21, and in the control children 31. In spite of the small material it thus seems unlikely that hypersensitivity plays an influential part in the etiology of children's recurrent abdominal pain.

The humoral immune response to Helicobacter pylori infection in children with recurrent abdominal pain

The systemic humoral immune response to Helicobacter pylori antigens was investigated in 36 children with recurrent abdominal pain (RAP). H. pylori was cultured and Helicobacter-like organisms (HLO) were seen in six children, three of whom had active and two inactive chronic gastritis. None of these children had endoscopic abnormalities. All sex children had increased IgG antibodies to heat-stable H. pylori antigens which were of the IgG1 and IgG3 subclasses. Using six other IgG tests, four of which were commercially available, two to five H. pylori-positive children were found seropositive. Five of six H. pylori-negative children with inactive chronic gastritis and no endoscopic abnormalities had increased IgM antibody levels in addition to increased or borderline increased IgG antibody levels to H. pylori, indicating activity in a chronic H. pylori infection. Five children without H. pylori and with no morphological changes, but with gastritis or duodenitis by endoscopy, had significantly lower IgG and IgA antibody levels compared to other groups. Six of nineteen children without H. pylori, and with no morphological or endoscopic changes had increased IgG and IgM antibody levels to H. pylori. All H. pylori-negative children were seronegative by the four commercial kits. Overall, 12 (33%) of 36 children with RAP were either H. pylori positive by culture and microscopy or had increased IgG antibody levels to H. pylori, which is significantly different from the 10-14% seropositive rate of asymptomatic children. H. pylori may therefore be a cause of RAP in one quarter to one third of the children with RAP in whom other etiologies of RAP are excluded. Further studies on a large number of children are needed for an extended evaluation of the humoral immune response to H. pylori and for further examination of commercial kits which seem to give a high number of false-negative results.

Helicobacter pylori antibodies in sera of children suffering from chronic abdominal pain

107 pediatric patients aged 9 to 18 with persistent gastric complaints were examined serologically and bacteriologically for Helicobacter pylori. Helicobacter was identified in 48 (45%) of individuals. 51 (48%) of children were found to be seropositive when H. pylori antibodies were detected by the ELISA; 56 (52%) when the passive haemagglutination test was used, and 41 (38%) in the latex agglutination test. 25% of culture-negative patients were found to be seropositive. The percentage of raised H. pylori antibody titres in the control (healthy subjects) varied from 20 to 27%, depending on the method applied.

The prevalence of Helicobacter pylori serum antibodies in children with recurrent abdominal pain

As part of a large, prospective study we investigated the prevalence Helicobacter pylori serum antibodies in children with recurrent abdominal pain (RAP). All patients suffered from recurrent bouts of abdominal pain for at least 6 months and ranged in age from 6 to 12 years. H. pylori antibodies were detected using an enzyme-linked immunosorbent assay. The prevalence of H. pylori antibodies in the RAP group was compared to that of a control group which consisted predominantly of pre-operative children. None of the control group suffered or had suffered from RAP. Antibodies to H. pylori were found in 7 of 82 (8.5%) RAP patients and in 2 of 39 (5.1%) control children. The latter difference is not significant and suggests that RAP is only rarely caused in children by H. pylori infection.

Immune responses to Helicobacter pylori in children with recurrent abdominal pain

The systemic immune response to Helicobacter pylori was examined in 69 children with recurrent abdominal pain and upper gastrointestinal symptoms. Twenty one (30%) children were histologically positive for H pylori. Eighteen of the 21 positive subjects and two H pylori negative subjects (one with normal mucosa, one with lymphocytic gastritis) were positive for H pylori IgG antibodies by enzyme linked immunosorbent assay (ELISA) (86% sensitivity, 98% specificity). In children with H pylori associated gastritis, there was a significant positive correlation (p less than 0.05) between IgG antibody titres and patient age. Intra-assay comparison of sera from histologically negative adults with those of histologically negative children showed that the cut off for positivity in the ELISA for adults was greater than that for children. Immunoblotting showed IgG positivity in 20 of the 21 patients with H pylori infection (95% sensitivity). Both ELISA and immunoblotting for IgA and IgM H pylori antibodies had poor discriminatory value for determining infection. Serological detection of H pylori IgG antibodies seems to be valuable in the assessment of children presenting with recurrent abdominal pain and other gastrointestinal symptoms, but assays must first be validated in paediatric populations.