Eosinophilic esophagitis that develops during therapy with proton pump inhibitors : case series and possible mechanisms

Therapy with proton-pump inhibitors (PPIs) results in remission in at least one third of patients with esophageal eosinophilia, presumably because of both their acid-related and anti-inflammatory mechanisms of action. However, eosinophilic esophagitis (EoE) may also develop during therapy with PPIs. We present a case series of four children who were initially diagnosed with infectious esophagitis, gastroesophageal reflux disease or gastric ulcer, who had no eosinophilic infiltration of the esophagus, but subsequently developed symptoms, endoscopic features and histological picture of typical EoE. We discuss mechanisms of action of PPIs of likely relevance to an increased risk of development of EoE in some patients, such as their influence on mucosal barrier function, interference with pH-related protein digestion by pepsin, and antigen processing by immune cells.

Infliximab delays but does not avoid the need for surgery in treatment-resistant pediatric Crohn' disease

The aim of this study was to review the impact of infliximab therapy on children with treatment-resistant Crohn's disease. Treatment resistance was defined as clinically active disease despite >4 months of immunosuppressive therapy. The outcome variables were time to first remission, duration of remission and the need for surgery. 24 children received 90 infusions of infliximab (16 boys; median 10.3y, range 1.0-14.4y); all had three infusions as an induction course. 17 (70.8%) achieved clinical remission, with 14/17 (82.3%) relapsing within 4 months of the third infusion. 6/7 in the non-responding group and 8/17 of the responders required surgery with an insignificant difference in the median time to surgery (p=0.49). Four remain dependent on regular infliximab. Infliximab is well-tolerated and highly effective in achieving clinical remission in children with refractory Crohn's disease but may only delay and not avoid the need for surgery. Failure to achieve clinical remission by the 3rd infusion significantly increases the risk of surgery.

A distinct subset of chemokines dominates the mucosal chemokine response in inflammatory bowel disease

BACKGROUND

Inflammatory bowel disease (IBD) is characterised by intense mucosal recruitment of activated leukocytes. Chemokines determine inflammatory leukocyte recruitment and retention.

AIM

To compare expression of the entire chemokine family within colonic mucosa from IBD patients and uninflamed controls.

METHODS

A microarray of cDNAs, representing every member of this superfamily and their cognate receptors, was hybridised with probes derived from colonoscopic biopsies.

RESULTS

A distinct subset of chemokines, consisting of CXCLs 1-3 and 8 and CCL20, was upregulated in active colonic IBD, compared with uninflamed areas or tissue from controls. Increased expression of their cognate receptors, CXCR1, CXCR2 and CCR6, was confirmed by quantitative PCR and immunohistochemistry. An identical chemokine response was induced in Caco-2 cells by stimulation with interleukin (IL)-1beta, but not tumour necrosis factor-alpha (TNF-alpha). By contrast, IL-1beta and TNF-alpha were synergistic in an HT29 cell line and primary keratinocytes.

CONCLUSIONS

IL-1beta and TNF-alpha appear to be the pivotal mediators of a previously unidentified coordinated epithelial chemokine response that dominates the mucosal chemokine environment in inflamed IBD tissue.

Early interactions of Salmonella enterica serovar typhimurium with human small intestinal epithelial explants

BACKGROUND

Salmonella enterica serovar typhimurium (S typhimurium) causes invasive gastroenteritis in humans, a disease involving significant penetration of the intestinal mucosa. However, few studies have been undertaken to investigate this interaction directly using differentiated human gut tissue.

AIMS

To investigate the early interactions of an enteropathogenic strain of S typhimurium with human intestinal mucosa using human intestinal in vitro organ culture (IVOC).

METHODS

Wild-type and mutant derivatives of S typhimurium TML were used to compare interactions with cultured human epithelial cells, bovine ligated loops, and human intestinal IVOC.

RESULTS

S typhimurium TML was shown to attach to cultured Caco-2 brush border expressing cells and cause tissue damage and fluid accumulation in a ligated bovine loop model.S typhimurium TML bound predominantly to the mucus layer of human IVOC explants during the first four hours of IVOC incubation. From four to eight hours of IVOC incubation, small but characteristic foci of attaching and invading S typhimurium TML were detected as clusters of bacteria interacting with enterocytes, although there was no evidence for large scale invasion of explant tissues. Ruffling of enterocyte membranes associated with adherent Salmonella was visualised using electron microscopy.

CONCLUSIONS

Human IVOC can be used as an alternative model for monitoring the interactions between S typhimurium and human intestinal epithelium, thus potentially offering insight into the early stages of human Salmonella induced gastroenteritis.

Improvement in quality of life of children with acute Crohn's disease does not parallel mucosal healing after treatment with exclusive enteral nutrition

BACKGROUND

Crohn's disease is a chronic debilitating disorder affecting a child's physical and emotional well-being. Recent emphasis on 'quality of life' (QOL) has led to re-evaluation of available medical treatments.

AIM

To assess prospectively change in QOL, clinical disease activity and intestinal mucosal inflammation in active paediatric Crohn's disease after treatment with exclusive enteral nutrition. In addition, we evaluated whether change in QOL could predict changes in paediatric Crohn's disease activity index (PCDAI) and mucosal inflammation (endoscopic and histologic).

METHODS

The IMPACT II questionnaire was used prospectively and longitudinally in 26 consecutively recruited children [16 males (67%), median 14 years, s.d. = 1.7 years] with active Crohn's disease (PCDAI > 20). They were treated with a new polymeric enteral feed (ACD004, Nestle) for a period of 8 weeks. All had PCDAI, QOL and endoscopic assessment at the time of diagnosis and after 8 weeks of treatment.

RESULTS

Twenty-three of 26 children achieved a clinical remission at 8 weeks, with improvement in the QOL scores (P < 0.05). The change in QOL score after treatment was predictive of achieving a clinical remission, but not of histological improvement.

CONCLUSIONS

Although children may find dietary restrictions difficult, this study confirms a clear improvement in QOL after treatment with exclusive enteral nutrition. However, improvement in QOL scores is not reflected by improvement in mucosal inflammation. Whilst improving QOL remains a core principal in patient management, the long-term consequences of ongoing mucosal inflammation must be better understood before relying only on short-term QOL measures to dictate treatment choices.

Refeeding syndrome with enteral nutrition in children: a case report, literature review and clinical guidelines

Refeeding syndrome is a potentially fatal complication of the nutritional management of severely malnourished patients. The syndrome almost always develops during the early stages of refeeding. It can be associated with a severe derangement in electrolyte and fluid balance, and result in significant morbidity and mortality. It is most often reported in adults receiving total parenteral nutrition (TPN), although refeeding with enteral feeds can also precipitate this syndrome. We report what we believe to be the first case of refeeding syndrome in an adolescent with newly diagnosed Crohn's disease. This developed within a few days of starting exclusive polymeric enteral nutrition. A systematic literature review revealed 27 children who developed refeeding syndrome after oral/enteral feeding. Of these, nine died as a direct result of complications of this syndrome. We discuss the implications of this syndrome on clinical practice and propose evidence-based guidelines for its management.

Tissue tropism of enteropathogenic Escherichia coli strains belonging to the O55 serogroup

Four enteropathogenic Escherichia coli (EPEC) strains belonging to the O55 serogroup (G21 and G30 [both O55:H6], G35 [O55:H-], and G58 [O55:H7]) were tested for their tissue tropism by using human intestinal in vitro organ culture. Strains showed restricted adhesion with attaching-and-effacing activity to follicle-associated epithelium of Peyer's patches, with no apparent adhesion to duodenum or colon. G35 and G58 express intimin gamma and show a similar tropism to intimin gamma-expressing enterohemorrhagic E. coli (EHEC) O157:H7. However, strains G21 and G30 were unusual because they expressed intimin alpha and had a restricted tissue tropism of intimin gamma phenotype. The amino acid sequence of the carboxy-terminal 280 amino acids of intimin from G21 was determined. Comparison with the prototype intimin alpha from strain E2348/69 (O127:H6) showed a single amino acid difference (corresponding to Val907 and Ala907 in the whole intimins). This mutation was reproduced by site-directed mutagenesis in an intimin alpha plasmid template, pCVD438, with the hypothesis that it may induce a change in tropism. However, when the mutated plasmid was placed in both EPEC and EHEC backgrounds, duodenal adhesion in a manner similar to strain E2348/69 was evident upon in vitro organ culture. Thus, additional factor(s) unrelated to intimin exist in the O55:H6 genome that influence human intestinal tissue tropism.

Inflammatory bowel disease associated with immune thrombocytopenic purpura in children

OBJECTIVE

Previous reports suggest an association between inflammatory bowel disease (IBD) and immune thrombocytopenic purpura (ITP) in adults. To date, only five children with both diseases have been described. The aim of the study was to describe the characteristics of children with IBD and ITP.

METHODS

Cases were obtained from the pediatric gastroenterology community by means of the pediatric gastroenterology internet bulletin board in June 1999. Eight cases were submitted from seven medical centers. Medical records were reviewed by two pediatric gastroenterologists and a pediatric hematologist.

RESULTS

The age range of the patients was 2.1 to 16.5 years, with a mean age of 9.6 +/- 5.2 years. Four children had ulcerative colitis, three had Crohn disease, and one had indeterminate colitis. All had colonic involvement of IBD. Of eight patients, three had IBD first, three had ITP first, and two had both simultaneously. At ITP diagnosis, platelet count was less than 10,000/mL in five children, 17,000/mL in one child, and 50,000 to 60,000/mL in two children. Of the three children diagnosed with ITP first, two initially had rectal bleeding at the time of ITP diagnosis. Bone marrow evaluations, performed in six of eight children, were consistent with ITP. Six of the eight children had chronic ITP, including three children who were 5 years of age or younger. Therapy for ITP included steroids (n = 6), intravenous immunoglobulin (n = 6), Rh o (D) intravenous immunoglobulin (n = 2), and splenectomy (n = 1).

CONCLUSIONS

The authors describe the largest pediatric case series of children with IBD and ITP. More than 50% of the children had the chronic form of ITP. Most patients responded to conventional therapy for ITP and IBD.

Reduced heparan sulfate accumulation in enterocytes contributes to protein-losing enteropathy in a congenital disorder of glycosylation

Intestinal biopsy in a boy with gastroenteritis-induced protein-losing enteropathy (PLE) showed loss of heparan sulfate (HS) and syndecan-1 core protein from the basolateral surface of the enterocytes, which improved after PLE subsided. Isoelectric focusing analysis of serum transferrin indicated a congenital disorder of glycosylation (CDG) and subsequent analysis showed three point mutations in the ALG6 gene encoding an alpha1,3-glucosyltransferase needed for the addition of the first glucose to the dolichol-linked oligosaccharide. The maternal mutation, C998T, causing an A333V substitution, has been shown to cause CDG-Ic, whereas the two paternal mutations, T391C (Y131H) and C924A (S308R) have not previously been reported. The mutations were tested for their ability to rescue faulty N:-linked glycosylation of carboxypeptidase Y in an ALG6-deficient Saccharomyces cerevisiae strain. Normal human ALG6 rescues glycosylation and A333V partially rescues, whereas the combined paternal mutations (Y131H and S308R) are ineffective. Underglycosylation resulting from each of these mutations is much more severe in rapidly dividing yeast. Similarly, incomplete protein glycosylation in the patient is most severe in rapidly dividing enterocytes during gastroenteritis-induced stress. Incomplete N:-linked glycosylation of an HS core protein and/or other biosynthetic enzymes may explain the selective localized loss of HS and PLE.

Speech concerns of hard-of-hearing adults

Speech concerns of adults with hearing loss were identified in a sample of 75 members of Self Help for Hard of Hearing People. A majority of subjects had noticed changes in their speech and were interested in speech conservation services.

Tumour necrosis factor-alpha and interferon-gamma production measured at the single cell level in normal and inflamed human intestine

The spot-ELISA technique has been used to enumerate the frequency of cells secreting tumor necrosis factor-alpha (TNF-alpha) and interferon-gamma (IFN-gamma), isolated from biopsies of normal intestine and from biopsies of children with inflammatory bowel disease. TNF-alpha production was undetectable in six out of 12 biopsies from normal intestine and in the other six biopsies it ranged from 60 to 580 TNF-alpha-secreting cells/10(6) isolated intestinal cells. In contrast, cells isolated from biopsies of children with Crohn's disease (n = 9) all showed elevated frequencies of TNF-alpha-secreting cells (500-12,000 secreting cells/10(6) cells). In ulcerative colitis, four out of eight children had increased production of TNF-alpha and in children with indeterminate colitis two out of three had elevated levels. There was no correlation between plasma TNF-alpha levels and the number of intestinal cells secreting TNF-alpha. In controls and all groups of patients IFN-gamma-secreting cells were uncommon. These results suggest that TNF-alpha is an important mediator of inflammation in the human gut, and, furthermore, may play a role in the growth failure frequently seen in children with inflammatory bowel disease.

Anorexia nervosa complicating inflammatory bowel disease

Two cases of inflammatory bowel disease, occurring in adolescence and complicated by anorexia nervosa, are presented. The management of the bowel disease with corticosteroids appeared to precipitate the eating disorder in one case whereas covert withdrawal of steroid treatment led to life threatening complications of inflammatory bowel disease in the other. The difficulties of managing two serious conditions, each ideally treated in a specialist centre, are discussed and the dangers of treating adolescents with shape modifying drugs are highlighted.