Non-infective colitis in infancy: evidence in favour of minor immunodeficiency in its pathogenesis

Effects of Jian Pi Qing Chang Hua Shi decoction on mucosal injuries in a 2,4,6-trinitrobenzene sulphonic acid-induced inflammatory bowel disease rat model

CONTEXT

Jian Pi Qing Chang Hua Shi decoction (JPQCHSD) has been considered as an effective remedy for the treatment of inflammatory bowel disease (IBD) in Chinese traditional medicine.

OBJECTIVE

We evaluated the efficacy of JPQCHSD on 2-4-6-trinitrobenzene sulphonic acid (TNBS)-induced IBD rats and the responsible mechanisms.

MATERIALS AND METHODS

Except the rats of the control group (50% ethanol), Sprague-Dawley rats (180 ± 20 g) induced by TNBS (150 mg/kg in 50% ethanol), received water extract of JPQCHSD daily at 0, 9.5, 19, or 38 g/kg for 12 days. The rats were sacrificed, and their colons were removed to evaluate the disease activity index. Malondialdehyde (MDA), superoxide dismutase (SOD), myeloperoxidase (MPO), immunoglobulin A (IgA), tumour necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and nuclear factor-κB were evaluated.

RESULTS

JPQCHSD extract significantly reduced the disease activity index of TNBS-induced colitis with a median effective dose (ED₅₀) of 26.93 g/kg. MPO and MDA were significantly reduced in the 19 and 38 g/kg groups (ED₅₀ values 37.38 and 53.2 g/kg, respectively). The ED₅₀ values for the increased SOD and IgA were 48.98 and 56.3 g/kg. ED₅₀ values for inhibition of TNF-α, IL-1β, and IL-6 were 32.66, 75.72, and 162.06 g/kg, respectively.

DISCUSSION

JPQCHSD promoted mucosal healing in IBD rats via its anti-inflammation, immune regulation, and antioxidation properties.

CONCLUSIONS

JPQCHSD has healing function on IBD. Further clinical trials are needed to demonstrate its efficacy and tolerance to IBD.

Etiologies and outcome of lower gastrointestinal bleeding in patients presenting to a tertiary care Children's Hospital

Objective:

To determine etiology and outcome of children with lower gastrointestinal bleeding (LGIB).

Methods:

This was a prospective study conducted at the Department of Pediatric Gastroenterology and Hepatology, Children’s Hospital and The Institute of Child’s Heath, Multan, Pakistan, from July 2019 to March 2020. A total of 148 cases presented with bleeding per rectum and underwent colonoscopy, were included. Children of both genders and aged three month to 15 years were included. Detailed history, clinical examination, laboratory studies, colonoscopy and histopathology were done in all cases. Study information like demographics, complaints, general clinical examination, colonoscopy and histopathological findings were recorded.

Results:

Overall, mean age was noted to be 7.20±1.83 years. Abdominal pain was reported in 41 (27.7%), diarrhea 36 (24.3%), fever 12 (8.1%) and constipation in 4 (2.7%). Pallor was noted among 68 (45.9%), weight loss 39 (26.3%) and tachycardia 31 (20.9%). Colonoscopy revealed juvenile colonic / rectal polyps, infectious colitis and solitary rectal ulcer (SRU) as the most common etiologies found among 58 (39.2%), 20 (13.5%) and 19 (12.8%) cases respectively. Juvenile polyps and non-specific colitis were the commonest histopathological findings seen in 55 (37.2%) and 20 (13.5%) cases respectively. Colonoscopic polypectomy was used to remove all juvenile polyps.

Conclusion:

LGIB is presentation of various underlying causes. Children with LGIB commonly present with abdominal pain. Juvenile polyps were the most frequent cause of LGIB among children flowed by non-specific colitis. Most of the children having LGIB were diagnosed and treated successfully, few are in remission and very few were found resistant to treatment.

Ileocolonic Lymphonodular Hyperplasia in Children Related to Etiologies Ranging from Food Hypersensitivity to Familial Mediterranean Fever

OBJECTIVE

We aimed to share our observations on the demographics, clinical characteristics, and outcomes of lymphonodular hyperplasia (LNH) in children.

SUBJECTS AND METHODS

The study included children on whom colonoscopy was performed between January 2015 and May 2018 (n = 361). Demographics, treatment modalities, and outcomes of the patients with LNH were recorded.

RESULTS

LNH was found in 66 patients (18.3%; mean age 8.6 ± 5.96 years, 59.1% male). We found that the etiologic factors were food hypersensitivity (FH) in 25 (37.8%), nonspecific colitis in 12 (18.2%), irritable bowel syndrome in 10 (15.2%), familial Mediter-ranean fever in 7 (10.6%), primary immunodeficiency in 4 (6.1%), and intestinal dysmotility, oxyuriasis, Crohn's disease, and giardiasis in 1 (1.5%) patient. Additionally, in the genetic analysis of patients with idiopathic LNH (n = 4), we detected heterozygote MEFV mutations in all. Cow's milk and egg (25%) were the most common allergens in patients with FH. Symptoms of all patients (n = 25) improved after an elimination diet.

CONCLUSIONS

LNH is a common finding in pediatric colonoscopies with a variety of etiologies ranging from FH and familial Mediterranean fever to immunodeficiency.

[Eosinophilic gastroenteritis and colitis in pediatric patients: Increasingly frequent diseases]

Eosinophilic gastrointestinal disorders are a heterogeneous group of disorders characterized by no specific digestive symptoms associated with dense eosinophilic inflammation of the gastrointestinal tract in the absence of known causes for such tissue eosinophilia. Among these diseases, eosinophilic gastroenteritis (EGE) and colitis (EC) are less common than esophagitis, but their incidence and prevalence have been increasing over the past decade due in part to increased disease recognition. The exact pathophysiology is not clear: EGE and EC are immune-mediated diseases implicating adaptive T-helper cell type 2 immunity. According to the site of eosinophilic infiltration, there is a wide spectrum of digestive symptoms ranging from food refusal, nausea, vomiting, abdominal pain, weight loss, gastrointestinal bleeding (anemia), protein loosing enteropathy, ascites, bowel obstruction or perforation for EGE and diarrhea ± bleeding for CE. Endoscopic lesions are not specific: friability, erythematous mucosa with superficial erosions, or ulceration is often observed. Histologically, markedly increased numbers of mucosal eosinophils are seen in biopsy specimens. However, no standards for the diagnosis of EGE or CE exist and few findings support the diagnosis: intraepithelial eosinophils, eosinophil crypt abscesses, and eosinophils in muscularis mucosa and/or submucosa. Other organs are not involved. The other causes of tissue eosinophilia (infections, inflammatory bowel diseases) should be excluded. Food allergy appears to play a central role in driving inflammation in EGE and CE, as evidenced by symptomatic improvement with initiation of food exclusion or elemental diets. Dietary treatment should be the first therapeutic option in children. If the elimination diet fails, corticosteroids are currently the best characterized treatment but appropriate duration is unknown and relapses are frequent. In severe forms, immunomodulators or biologic agents (anti-IL5, anti-IgE, or anti-TNFa) can potentially play a role in the treatment of EGE and CE.

The diagnostic approach to monogenic very early onset inflammatory bowel disease

Patients with a diverse spectrum of rare genetic disorders can present with inflammatory bowel disease (monogenic IBD). Patients with these disorders often develop symptoms during infancy or early childhood, along with endoscopic or histological features of Crohn's disease, ulcerative colitis, or IBD unclassified. Defects in interleukin-10 signaling have a Mendelian inheritance pattern with complete penetrance of intestinal inflammation. Several genetic defects that disturb intestinal epithelial barrier function or affect innate and adaptive immune function have incomplete penetrance of the IBD-like phenotype. Several of these monogenic conditions do not respond to conventional therapy and are associated with high morbidity and mortality. Due to the broad spectrum of these extremely rare diseases, a correct diagnosis is frequently a challenge and often delayed. In many cases, these diseases cannot be categorized based on standard histological and immunologic features of IBD. Genetic analysis is required to identify the cause of the disorder and offer the patient appropriate treatment options, which include medical therapy, surgery, or allogeneic hematopoietic stem cell transplantation. In addition, diagnosis based on genetic analysis can lead to genetic counseling for family members of patients. We describe key intestinal, extraintestinal, and laboratory features of 50 genetic variants associated with IBD-like intestinal inflammation. In addition, we provide approaches for identifying patients likely to have these disorders. We also discuss classic approaches to identify these variants in patients, starting with phenotypic and functional assessments that lead to analysis of candidate genes. As a complementary approach, we discuss parallel genetic screening using next-generation sequencing followed by functional confirmation of genetic defects.

Intraepithelial lymphocyte eotaxin-2 expression and perineural mast cell degranulation differentiate allergic/eosinophilic colitis from classic IBD

OBJECTIVES

Allergic colitis shows overlap with classic inflammatory bowel disease (IBD). Clinically, allergic colitis is associated with dysmotility and abdominal pain, and mucosal eosinophilia is characteristic. We thus aimed to characterise mucosal changes in children with allergic colitis compared with normal tissue and classic IBD, focusing on potential interaction between eosinophils and mast cells with enteric neurones.

METHODS

A total of 15 children with allergic colitis, 10 with Crohn disease (CD), 10 with ulcerative colitis (UC), and 10 histologically normal controls were studied. Mucosal biopsies were stained for CD3 T cells, Ki-67, eotaxin-1, and eotaxin-2. Eotaxin-2, IgE, and tryptase were localised compared with mucosal nerves, using neuronal markers neurofilament protein, neuron-specific enolase, and nerve growth factor receptor.

RESULTS

Overall inflammation was greater in patients with CD and UC than in patients with allergic colitis. CD3 T-cell density was increased in patients with allergic colitis, similar to that in patients with CD but lower than in patients with UC, whereas eosinophil density was higher than in all other groups. Eotaxin-1 and -2 were localised to basolateral crypt epithelium in all specimens, with eotaxin-1+ lamina propria cells found in all of the colitis groups. Eotaxin-2+ intraepithelial lymphocyte (IEL) density was significantly higher in allergic colitis specimens than in all other groups. Mast cell degranulation was strikingly increased in patients with allergic colitis (12/15) compared with that in patients with UC (1/10) and CD (0/1). Tryptase and IgE colocalised on enteric neurons in patients with allergic colitis but rarely in patients with IBD.

CONCLUSIONS

Eotaxin-2+ IELs may contribute to the periepithelial eosinophil accumulation characteristic of allergic colitis. The colocalisation of IgE and tryptase with mucosal enteric nerves is likely to promote the dysmotility and visceral hyperalgesia classically seen in allergic gastrointestinal inflammation.

Interleukin-10 receptor mutations in children with neonatal-onset Crohn's disease and intractable ulcerating enterocolitis

Neonatal-onset inflammatory bowel disease (IBD) accounts for only 0.25% of pediatric IBD cases. The molecular pathogenesis of IBD remains unclear. Recently, rare Mendelian mutations have been identified in children with very early-onset Crohn's disease and ulcerative colitis. In this study, we report compound heterozygous mutations in the interleukin-10 receptor A (IL-10RA) gene in children with severe neonatal-onset IBD. Patient 1 had chronic diarrhea within the first month of life and had perianal fistulae. She was diagnosed with 'intractable ulcerating enterocolitis in infancy' and underwent subtotal colectomy at the age of 24 months because of poor response to immunosuppressant therapy. Compound heterozygous mutations, c.[301C>T];[350G>A](p.[R101W];[R117H]), were discovered in IL-10RA for this patient. Patient 2 presented symptoms within the first month of life and was diagnosed with Crohn's disease. Severe colitis and perianal and enteroenteric fistulae occurred repeatedly, and he underwent surgical management involving colectomy, colostomy, and ileostomy. We identified mutations in IL-10RA, c.[272A>G];[784C>T] (p.[Y91C];[R262C]). Patient 3 had chronic diarrhea and a rectovaginal fistula at 3 days of life and was diagnosed with Crohn's disease. She underwent fistulectomy and ileostomy, but experienced frequent relapses. Mutations, c.[272A>G];[301C>T] (p.[Y91C];[R101W]), were found in IL-10RA. This report confirms the genetic defect of IL-10RA in neonatal-onset IBD including 'intractable ulcerating enterocolitis in infancy'.

Characteristics of allergic colitis in breast-fed infants in the absence of cow's milk allergy

AIM

To investigate the characteristics of mucosal lesions and their relation to laboratory data and long-term follow up in breast-fed infants with allergic colitis.

METHODS

In this study 31 breast-fed infants were prospectively evaluated (mean age, 17.4 wk) whose rectal bleeding had not ceased after a maternal elimination diet for cow's milk. Thirty-four age-matched and breast-fed infants (mean age, 16.9 wk) with no rectal bleeding were enrolled for laboratory testing as controls. Laboratory findings, colonoscopic and histological characteristics were prospectively evaluated in infants with rectal bleeding. Long-term follow-up with different nutritional regimes (L-amino-acid based formula or breastfeeding) was also included.

RESULTS

Iron deficiency, peripheral eosinophilia and thrombocytosis were significantly higher in patients with allergic colitis in comparison to controls (8.4 ± 3.2 μmol/L vs 13.7 ± 4.7 μmol/L, P < 0.001; 0.67 ± 0.49 G/L vs 0.33 ± 0.17 G/L, P < 0.001; 474 ± 123 G/L vs 376 ± 89 G/L, P < 0.001, respectively). At colonoscopy, lymphonodular hyperplasia or aphthous ulceration were present in 83% of patients. Twenty-two patients were given L-amino acid-based formula and 8 continued the previous feeding. Time to cessation of rectal bleeding was shorter in the special formula feeding group (mean, 1.4 wk; range, 0.5-3 wk) when compared with the breast-feeding group (mean, 5.3 wk; range, 2-9 wk). Nevertheless, none of the patients exhibited rectal bleeding at the 3-mo visit irrespective of the type of feeding. Peripheral eosinophilia and cessation of rectal bleeding after administration of elemental formula correlated with a higher density of mucosal eosinophils.

CONCLUSION

Infant hematochezia, after cow's milk allergy exclusion, is generally a benign and probably self-limiting disorder despite marked mucosal abnormality. Formula feeding results in shorter time to cessation of rectal bleeding; however, breast-feeding should not be discouraged in long-lasting hematochezia.

Etiology of lower gastrointestinal bleeding in children:a single center experience from southern iran

BACKGROUND

This study aimed to determine the common etiologies and characteristics of lower gastrointestinal (GI) bleeding in children from Southern Iran.

METHODS

This five-year prospective cross-sectional study was performed from March 2006 to March 2011 in Nemazee Hospital. All pediatric patients (<18 years of age) who referred to our center with gross lower GI bleeding or two consecutive positive occult blood tests with at least a one-week interval were included in the study. Patients were categorized as neonates, infants, children and adolescents and the findings were reported separately in each group. Each patient underwent a colonoscopy and several mucosal biopsies were taken. Demographic and clinical information as well as colonoscopy and pathology findings were reported.

RESULTS

Overall, we included 363 pediatric patients with a mean age of 71.9±58.4 months (range: 1-216 months). There were 215 (59.2%) boys and 148 (40.8%) girls. The most common colonoscopy findings were sigmoid colon polyp in 91 (25.1%) patients followed by descending colon petechia in 78 (21.5%) patients, whitish rectal lesions in 45 (12.4%) patients, and sigmoid and rectal ulcers in 37 (10.2%) patients. Biopsy samples were non-specific in 96 (26.4%) patients. The most common pathological findings were juvenile polyp in 84 (23.1%) followed by lymphoid nodular hyperplasia in 55 (15.2%) and solitary rectal ulcers in 25 (6.9%) patients.

CONCLUSION

We found that lower GI bleeding was more common among 2-10 year-old children and was rarely encountered in neonates. Hematochezia was the most common form of presentation followed by bloody diarrhea and occult blood. The most common colonoscopy finding was sigmoid colon polyp and the most common pathological finding was juvenile polyp.

Inflammatory bowel diseases in patients with adaptive and complement immunodeficiency disorders

Crohn's disease and ulcerative colitis are idiopathic chronic inflammatory diseases that primarily affect the gastrointestinal tract. The underlying causes remain poorly understood, but there is a growing body of evidence advocating a likely primary pathogenic role for immunodeficiency in the development of Crohn's lesions. Concordantly, a number of congenital immunodeficiencies disrupting the cellular innate immune system strongly predispose to noninfectious, Crohn's-like inflammatory bowel disease. There are case reports and series suggesting that the same may be true for some of the congenital adaptive and complement immunodeficiencies. This review considers and critiques these potential associations.

Regulatory T cells and T helper subsets in breast-fed infants with hematochezia caused by allergic colitis

The objective of our study was to investigate the prevalence of CD4 T lymphocyte subsets and their commitment to TH1 or TH2 direction in 10 infants with allergic colitis (AC) and 10 healthy controls. Infants with AC presented with a higher ratio of naïve to memory cells, lower prevalence of activated CD4CD25 cells and FoxP3 regulatory cells, and a shift to TH2 direction in balance compared with controls. These alterations are normalized upon cessation of AC symptoms on elemental L-amino acid formula. These findings suggest the importance of antigen exposure in AC in infancy.

Ineffectiveness of infliximab therapy in severe infantile Crohn's disease

Crohn's disease is extremely rare in infancy and can be present in severe forms. Infants with Crohn's disease might require intensive immunosuppressive therapy. Infliximab is a chimeric mouse/human monoclonal IgG1 antibody against tumor necrosis factor-α, and completely neutralizes its biologic activity. Though widely used in the treatment of pediatric Crohn's disease, there are few data regarding its applicability in infancy. We therefore report herein our experiences with infliximab therapy in two infantile patients with Crohn's disease who were resistant to conventional therapies; one patient showed a partial response while there was no response in the second. We were unable to achieve satisfactory results from infliximab therapy. It remains to be determined whether inflammatory bowel disease starting in infancy represents a separate pathogenetic subgroup and whether the inflammatory bowel disease diagnosis should follow the exclusion of an immunodeficiency state. Studies in larger series are needed to further clarify the efficacy, safety and timing of infliximab therapy for infantile Crohn's disease patients.

Anti-TNFα antibody infliximab treatment for an infant with fistulising Crohn's disease

A female infant presented at the age of 4 weeks with dyschezia and bloody streaking of stools which did not improve on elemental formula for proposed cow's milk protein allergy. At 6 months of age perianal ulceration appeared which evolved into multiple fistulas opening into the perineum. A diagnosis of infantile Crohn's disease was made after colonoscopy and histopathology examination and exclusion of other conditions. An 8 week trial of total parenteral nutrition, in addition to corticosteroids, salazopyrine, metronidazole, and azathioprine failed to arrest deterioration of the perianal fistulas. Treatment with the anti-TNFα antibody infliximab was started at 5 mg/kg/dose at 9 months of age. She was given three doses at 0, 2, and 6 weeks, respectively. This resulted in significant healing of her fistulas and cessation of fistula output. This improvement was sustained at the time of last follow-up 10 months after treatment.

Intestinal microbiota in exclusively breast-fed infants with blood-streaked stools

Intestinal microbiota in exclusively breast-fed infants with blood-streaked stools and in healthy exclusively breast-fed babies was compared. Total anaerobes, bifidobacteria, lactobacilli, coliform bacteria, enterococci and clostridia were quantified by cultivation methods in feces of 17 full-term exclusively breastfed patients (aged 16.3 +/- 7.4 weeks) with blood-streaked stools and in the control group of 22 healthy fullterm exclusively breast-fed infants (13.7 +/- 6.4 weeks). Specific fluorescence in situ hybridization kits for Bifidobacterium spp. were used for the quantitative detection of bifidobacteria in samples. Control samples had significantly (p < 0.05) higher counts of total anaerobes. Bifidobacteria were not detected in patients' samples in 65 % and in controls in 36 % (p < 0.01). Bifidobacteria counts were also significantly higher in the control group (p < 0.01). Furthermore, clostridia strains were detected only in feces from bifidobacteria-negative infants reaching counts >8 log CFU/g. Lactobacilli were not detected in 65 % patients and in 45 % control samples. However, this difference was not significant as well as the difference in lactobacilli counts. Eosinophilia was observed in 35 % of patients, low IgA concentration in 71 % and also low IgG concentration in 71 %. pANCA positivity was found in 53 % of patients. In conclusion a significant low proportion of bifidobacterial microbiota in patients with blood-streaked stools was shown in comparison with controls.

IBD and IBD mimicking enterocolitis in children younger than 2 years of age

Inflammatory bowel disease (IBD) is uncommon in children younger than 2 years of age. The criteria for differentiating IBD from other diseases with similar clinical presentation is unclear. We describe 16 patients who, between 1984 and 2004, received a histological diagnosis of IBD during the first two years of life. Six patients presented with histological Crohn's disease, eight with ulcerative colitis and two with indeterminate colitis. The median age at diagnosis was 125 days (range 1 day to 18 months) and the medium follow up was 89 months (range 65 days to 20 years). The disease appeared to be very severe: four children (25%) underwent total parenteral nutrition (TPN), two received colectomy (12.5%) and three patients died. Many of the patients required an aggressive, multidrug, immunosuppressive approach (azathioprine [AZA], Infliximab, thalidomide, cyclosporine A). One child presented with a hypogammaglobulinaemia without any specific immunodeficiency, while in the other patients, Wiskott-Aldrich syndrome (WAS) (4 cases) and chronic granulomatous disease (CGD) (2 cases) were identified. In 6/16 cases, allergic colitis was first considered; these cases initially underwent cow's milk protein-free diet as the only therapy before IBD was finally diagnosed. In conclusion, early IBD has a severe prognosis and often needs an aggressive therapeutic approach. Furthermore, an improper diagnosis of allergic colitis might cause an important diagnostic delay. Some severe immunodeficiencies, such as WAS and CGD, may represent a problem in terms of differential diagnosis and might be wrongly diagnosed as very early onset IBD.

Rectal bleeding in infancy: clinical, allergological, and microbiological examination

OBJECTIVE

Rectal bleeding is an alarming symptom and requires additional investigation. In infants it has been explained mainly by hypersensitivity. In addition to dietary antigens, intraluminal microbial agents challenge the immature gut mucosa. Although controlled in the mature gut, these antigens may induce inflammation in the developing gastrointestinal tract. The objectives of this study were to evaluate prospectively the clinical course of rectal bleeding and evaluate the impact of cow's milk allergy and aberrant gut microbiota on the condition. Because withdrawal of cow's milk antigens from the infants' diet is used as a first treatment without evidence of its efficacy, we also aimed to asses the effect of a cow's milk-elimination diet on the duration of rectal bleeding.

METHODS

The study involved 40 consecutive infants (mean age: 2.7 months) with visible rectal bleeding during a 2-year period at the Tampere University Hospital Department of Pediatrics. Most of the infants (68%) were fully breastfed. At enrollment the infants were randomly allocated to receive a cow's milk-elimination diet (n = 19) or continue their previous diet (n = 21) for 1 month. Findings of colonoscopy, fecal bacterial culture, fluorescence in situ hybridization of selected gut genera, specific detection of fecal enteroviruses, rotaviruses, and adenoviruses, fecal electron microscopy for viruses, and mucosal electron microscopy for viruses were assessed. During each visit the severity of atopic eczema, if any, was assessed according to the SCORAD method. In evaluating the extent of sensitization, serum total immunoglobulin E (IgE) and specific IgE and skin-prick tests for cow's milk, egg, and wheat were studied. Cow's milk allergy was diagnosed by elimination and provocation testing. Five patients were hospitalized; all others were treated on an outpatient basis. The follow-up visits were scheduled 1 month later and at the age of 1 year. Sixty-four healthy reference infants were selected as controls according to the following criteria: age and timing of fecal sampling being identical to within 1 month.

RESULTS

Altogether, 32 (80%) infants manifested bloody stools during follow-up (mean [range]: 2.1 [1-15] per day). The mean number of days with rectal bleeding on follow-up was 6. Typically, bloody stools occurred irregularly, for which reason the mean time to the last occurrence of rectal bleeding was 24 (range: 1-85) days from admission. Atopic eczema at presentation or during follow-up was diagnosed in 38% of the infants. Increased specific IgE concentrations or a positive skin-prick test were uncommon. The growth of the infants was normal on admission and during follow-up. Colonoscopy revealed typically focal mucosal erythema and aphthous ulcerations. The mucosa appeared normal in less than half of the patients. No anorectal fissures or colonic polyps were found. Light microscopy revealed that the overall architecture of the mucosa was well maintained. Acute inflammation or postinflammatory state and focal infiltration of eosinophils in the lamina propria were the most common abnormalities. A cow's milk-elimination diet did not affect the duration of rectal bleeding. Cow's milk allergy was diagnosed in 7 (18%) patients. Virus-particle aggregates were found in the microvillus layer of the colon epithelium in 8 cases. The surface epithelium of the virus-positive colon biopsy specimens regularly showed degenerative changes in the microvillus layer and epithelial cells. Electron microscopy study of the colon biopsies disclosed virus particles (30 nm in diameter) on the surface of epithelial cells. Virus particles or RNA were present in feces in only a minority of the patients. All fecal cultures were negative for Salmonella, Shigella, and Yersinia. Campylobacter jejuni was found in the feces of 1 patient, and fecal cultures were positive for Clostridium difficile in 4 patients, Staphylococcus aureus in 8 patients, and yeast in 2 patients. Fluorescence in situ hybridization revealed that at the time of admission the total numbers of bacteria and the numbers of bifidobacteria and lactobacilli in feces were lower in the patients compared with controls. The fecal concentrations of microbes characterized in this study (Bacteroides, bifidobacteria, Clostridium, lactobacilli, and enterococci) did not differ significantly between the time of admission and the second visit in the patients or controls. At the age of 1 year, 7 patients still suffered from cow's milk allergy, 5 of whom also suffered from multiple food allergies. Atopic eczema and histopathologically confirmed inflammation of the colonic mucosa at presentation were associated with persistence of cow's milk allergy at the age of 1 year. No patients exhibited gastrointestinal complaints or visible blood in stools.

CONCLUSIONS

Rectal bleeding in infants is generally a benign and self-limiting disorder. Bloody stools occurred irregularly for only a few days during the following months. As in a previous report, most infants were exclusively breastfed. In the majority of the patients the cause of the condition remains unknown. An association with viruses can be seen in some patients. The microbes that commonly lead to bloody diarrhea in older children and adults, Salmonella, Shigella, and Yersinia, were absent in the present material. The low bifidobacterial numbers in fecal samples may indicate a significant aberrance that may provide a target for probiotic intervention to normalize gut microbiota. The gut microbiota overall seemed stable, because the numbers of major groups of microbiota tested did not change significantly between the time of admission and after 1 month. Cow's milk allergy among these patients is more uncommon than previously believed. Cow's milk challenge is thus essential in infants who become symptom-free during a cow's milk-free diet to reduce the number of false-positive cow's milk-allergy diagnoses.

Long-term outcome of intractable ulcerating enterocolitis of infancy

BACKGROUND

Chronic enterocolitis is rare in infancy and accounts for less than 0.5% of all newly diagnosed inflammatory bowel disease (IBD) in the UK. Presentation at this young age is usually indicative of underlying immunodeficiency/immunodysregulation. A group of such infants suffer intractable ulcerating enterocolitis of infancy (IE) in which there is a pan-enteritis with marked oro-anal involvement and deep flask like mucosal ulcers throughout the colon.

METHODS

Retrospective review of presenting features, treatment and long-term outcome in a series of 8 children with typical IE.

RESULTS

The 8 children were aged between 1 and 4 weeks at onset (median 2 weeks, mean 2.3 weeks), of which 7 were followed up for 2-22 years (median 7.5 years, mean 11 years). All 8 children had an intractable disease course requiring a colectomy for control of symptoms. The median age at colectomy was 1.7 years (range 4 months-4 years). Three children developed a generalised lymphadenopathy due to uncontrolled EBV-related lymphoid proliferations (ages 4, 12, 18). These comprised a monomorphous B-lymphoycte lympho-proliferative disorder, a large pleomorphic follicular lymphoma, and a high grade pleomorphic B cell non-Hodgkin's lymphoma.

CONCLUSIONS

Infants with IE have a high risk of developing lymphomatous proliferations that appears to be related to the underlying immunodysregulation. Use of aggressive immunosuppression and acquisition of EBV infection appears to accelerate this process; hence we advocate early colectomy in confirmed cases. In children with IE screening for EBV and vigilance for abnormal lymphoid proliferations is paramount.

A consistent pattern of minor immunodeficiency and subtle enteropathy in children with multiple food allergy

OBJECTIVE

Although immunoglobulin (Ig)E-mediated allergies are readily identifiable, non-IgE-mediated allergies present more diagnostic difficulty. We performed a formal retrospective analysis to determine whether there is a recognizable clinical pattern in children.

METHODS

We studied 121 children (mean age, 17.3 months) with multiple food allergies who were recruited on the basis of adequate immunological assessment by using case notes and parental questionnaire.

RESULTS

Group 1 (n=44) had rapid reactions to dietary antigens, of whom 41 also showed delayed reactions. Group 2 (n=77) had delayed reactions only. Mean IgE was increased in group 1 but both groups otherwise shared a pattern of increased IgG1, decreased IgG2/4, and low-normal IgA. Lymphocyte subsets were skewed, with an increased percentage of CD4 and CD19 and decreased CD8 and natural killer cells. Gastroesophageal reflux, esophagitis, subtle enteropathy, and constipation were frequent in both groups. Of 55 exclusively breast-fed infants, 44 sensitized before weaning. Twenty-one of the mothers suffered from autoimmunity.

CONCLUSIONS

There appears to be a recognizable pattern of immune deviation and minor enteropathy in children with multiple food allergy, irrespective of the speed of reactions. Disturbed gut motility is particularly common, as is a maternal history of autoimmunity.

Increased frequency of intestinal Escherichia coli carrying genes for S fimbriae and haemolysin in IgA-deficient individuals

Persons with selective IgA deficiency carry an increased risk of coeliac disease, inflammatory bowel disease and perhaps also gastrointestinal malignancies. Inflammatory bowel disease is associated with an increased carriage of adherent and haemolytic Escherichia coli in the intestinal microflora. This study was designed to investigate whether IgA-deficient individuals carry E. coli with virulence-associated properties in their gut flora. The last free-lying colony of E. coli isolates obtained from rectal flora of 25 IgA-deficient and 20 age-matched control individuals was assayed by multiplex PCR for genes for the following adhesins or virulence determinants: P, type 1 and S fimbriae, Dr haemagglutinin, haemolysin, aerobactin and the capsular types K1 and K5. E. coli strains from the intestinal microflora of IgA-deficient individuals more often had the gene for S fimbriae (36% of the strains compared with 0% in control subjects, P=0.003) as well as for haemolysin (40 vs 10% of the strains, P=0.040). IgA-deficient individuals had instead lower frequencies of E. coli carrying genes for type 1 fimbriae in their microflora (68 vs 90%, P=0.14). The results suggest that IgA-deficient individuals carry an increased frequency of E. coli with potentially inflammatogenic properties in their microflora, which may contribute to the development of gastrointestinal disorders such as inflammatory bowel diseases.

Colonic CD8 and gamma delta T-cell infiltration with epithelial damage in children with autism

OBJECTIVES

We have reported colitis with ileal lymphoid nodular hyperplasia (LNH) in children with regressive autism. The aims of this study were to characterize this lesion and determine whether LNH is specific for autism.

METHODS

Ileo-colonoscopy was performed in 21 consecutively evaluated children with autistic spectrum disorders and bowel symptoms. Blinded comparison was made with 8 children with histologically normal ileum and colon, 10 developmentally normal children with ileal LNH, 15 with Crohn's disease, and 14 with ulcerative colitis. Immunohistochemistry was performed for cell lineage and functional markers, and histochemistry was performed for glycosaminoglycans and basement membrane thickness.

RESULTS

Histology demonstrated lymphocytic colitis in the autistic children, less severe than classical inflammatory bowel disease. However, basement membrane thickness and mucosal gamma delta cell density were significantly increased above those of all other groups including patients with inflammatory bowel disease. CD8(+) density and intraepithelial lymphocyte numbers were higher than those in the Crohn's disease, LNH, and normal control groups; and CD3 and plasma cell density and crypt proliferation were higher than those in normal and LNH control groups. Epithelial, but not lamina propria, glycosaminoglycans were disrupted. However, the epithelium was HLA-DR(-), suggesting a predominantly T(H)2 response.

INTERPRETATION

Immunohistochemistry confirms a distinct lymphocytic colitis in autistic spectrum disorders in which the epithelium appears particularly affected. This is consistent with increasing evidence for gut epithelial dysfunction in autism.

Dietary protein enterocolitis

Dietary protein enterocolitis generally presents in the 1st year of life with diarrhea, emesis, and irritability. When there is a delay in diagnosis, persistent exposure to the offending dietary antigen leads to increasing enteric inflammation manifesting as bloody diarrhea, anemia, dehydration, and failure to sustain normal patterns of weight gain and growth. The extent of enteric inflammation may be limited to mild proctitis, pancolitis, or true enterocolitis with esophagitis, gastritis, enteropathy, and colitis. The offending antigen is usually cow's milk protein or soy protein. A significant number of the infants are exclusively breast fed, especially those with proctitis. In older children, a wide variety of dietary proteins have been implicated. The inconsistency between allergists and gastroenterologists in the clinical definition of the syndrome remains a significant problem. To the allergist, the definition is based on clinical criteria, allergy testing, and response to double-blind food challenge, whereas to the gastroenterologist, it is defined by histologic criteria and the response of clinical and histologic manifestations to elimination diets. To further complicate the issue, European studies have emphasized the alterations in enteric permeability noted in both enteropathy and enterocolitis. In an effort to establish a unified approach, the International Life Sciences Institute sponsored a workshop in late 1998, which resulted in a document entitled "Classification of Gastrointestinal Disease of Infants and Children Due to Adverse Immunologic Reactions."

Cow's milk enteropathy: surgical pitfalls

BACKGROUND

Cow's milk-induced intestinal bleeding is a well-recognized cause of rectal bleeding in infancy. The authors report on 5 older children who presented with either visible rectal bleeding or profound anemia associated with occult intestinal bleeding secondary to cow's milk enteropathy.

METHODS

Five children (3 boys and 2 girls) aged between 20 months and 9 years were referred for further investigation of gastrointestinal bleeding. Two had been investigated previously on multiple occasions, and both had undergone laparotomies with negative results. Further investigations showed evidence of allergic colitis in 3 detected only on proximal colonic biopsy findings.

RESULTS

In all cases, bleeding resolved completely after instituting a cow's milk-free diet. Two of the patients subsequently have undergone a cow's milk challenge leading to prompt recurrence of symptoms, which again resolved after simple dietary manipulation.

CONCLUSIONS

Cow's milk enteropathy may cause overt rectal bleeding or profound anemia from occult intestinal bleeding even in older children. Histological abnormalities in such cases may be confined to the proximal colon. After appropriate investigation, a trial of cow's milk exclusion should always be considered before laparotomy for obscure, chronic gastrointestinal bleeding in children.