Reliability of histologic assessment in patients with eosinophilic oesophagitis

BACKGROUND

The validity of the eosinophilic oesophagitis (EoE) histologic scoring system (EoEHSS) has been demonstrated, but only preliminary reliability data exist.

AIM

Formally assess the reliability of the EoEHSS and additional histologic features.

METHODS

Four expert gastrointestinal pathologists independently reviewed slides from adult patients with EoE (N = 45) twice, in random order, using standardised training materials and scoring conventions for the EoEHSS and additional histologic features agreed upon during a modified Delphi process. Intra- and inter-rater reliability for scoring the EoEHSS, a visual analogue scale (VAS) of overall histopathologic disease severity, and additional histologic features were assessed using intra-class correlation coefficients (ICCs).

RESULTS

Almost perfect intra-rater reliability was observed for the composite EoEHSS scores and the VAS. Inter-rater reliability was also almost perfect for the composite EoEHSS scores and substantial for the VAS. Of the EoEHSS items, eosinophilic inflammation was associated with the highest ICC estimates and consistent with almost perfect intra- and inter-rater reliability. With the exception of dyskeratotic epithelial cells and surface epithelial alteration, ICC estimates for the remaining EoEHSS items were above the benchmarks for substantial intra-rater, and moderate inter-rater reliability. Estimation of peak eosinophil count and number of lamina propria eosinophils were associated with the highest ICC estimates among the exploratory items.

CONCLUSION

The composite EoEHSS and most component items are associated with substantial reliability when assessed by central pathologists. Future studies should assess responsiveness of the score to change after a therapeutic intervention to facilitate its use in clinical trials.

Targeting granulocyte-macrophage colony-stimulating factor in epithelial and vascular remodeling in experimental eosinophilic esophagitis

BACKGROUND

Eosinophilic esophagitis (EoE) is a chronic antigen-mediated clinicopathologic disease of the esophagus characterized by an eosinophil-predominant inflammatory infiltrate. A clinical hallmark is extensive tissue remodeling including basal zone hyperplasia, fibrosis, and angiogenesis. However, the cellular mechanisms responsible for these processes are not fully defined. We hypothesized that targeting granulocyte-macrophage colony-stimulating factor (GM-CSF; an agonist cytokine linked with eosinophil survival and activation) would be protective in a preclinical model of EoE.

METHODS

Eosinophilic esophagitis-like esophageal inflammation was induced in the L2-IL5^OXA EoE mouse model, and GM-CSF production was assessed by mRNA and protein analyses. Granulocyte-macrophage colony-stimulating factor-receptor-alpha expression patterns were examined by flow cytometric and immunofluorescence analysis. L2-IL5^OXA EoE mice were treated with anti-GM-CSF neutralizing antibody or isotype control and assessed for histopathological indices of eosinophilia, epithelial hyperplasia, and angiogenesis by immunohistochemistry and RT-PCR.

RESULTS

Significantly increased levels of esophageal GM-CSF expression was detected in the L2-IL5^OXA mouse EoE model during active inflammation. Granulocyte-macrophage colony-stimulating factor-receptor-alpha was predominantly expressed on esophageal eosinophils during EoE, in addition to select cells within the lamina propria. Anti-GM-CSF neutralization in L2-IL5^OXA EoE mice resulted in a significant diminution of epithelial eosinophilia in addition to basal cell hyperplasia and vascular remodeling. This treatment response was independent of effects on esophageal eosinophil maturation or activation.

CONCLUSION

Granulocyte-macrophage colony-stimulating factor is a potential therapeutic target to reduce esophageal eosinophilia and remodeling.

Epithelial-specific A2B adenosine receptor signaling protects the colonic epithelial barrier during acute colitis

Central to inflammatory bowel disease (IBD) pathogenesis is loss of mucosal barrier function. Emerging evidence implicates extracellular adenosine signaling in attenuating mucosal inflammation. We hypothesized that adenosine-mediated protection from intestinal barrier dysfunction involves tissue-specific signaling through the A2B adenosine receptor (Adora2b) at the intestinal mucosal surface. To address this hypothesis, we combined pharmacologic studies and studies in mice with global or tissue-specific deletion of the Adora2b receptor. Adora2b(-/-) mice experienced a significantly heightened severity of colitis, associated with a more acute onset of disease and loss of intestinal epithelial barrier function. Comparison of mice with Adora2b deletion on vascular endothelial cells (Adora2b(fl/fl)VeCadCre(+)) or intestinal epithelia (Adora2b(fl/fl)VillinCre(+)) revealed a selective role for epithelial Adora2b signaling in attenuating colonic inflammation. In vitro studies with Adora2b knockdown in intestinal epithelial cultures or pharmacologic studies highlighted Adora2b-driven phosphorylation of vasodilator-stimulated phosphoprotein (VASP) as a specific barrier repair response. Similarly, in vivo studies in genetic mouse models or treatment studies with an Adora2b agonist (BAY 60-6583) recapitulate these findings. Taken together, our results suggest that intestinal epithelial Adora2b signaling provides protection during intestinal inflammation via enhancing mucosal barrier responses.

Eosinophilic oesophagitis: relationship of quality of life with clinical, endoscopic and histological activity

BACKGROUND

Knowledge about determinants of quality of life (QoL) in eosinophilic oesophagitis (EoO) patients helps to identify patients at risk of experiencing poor QoL and to tailor therapeutic interventions accordingly.

AIM

To evaluate the impact of symptom severity, endoscopic and histological activity on EoE-specific QoL in adult EoE patients.

METHODS

Ninety-eight adult EoE patients were prospectively included (64% male, median age 39 years). Patients completed two validated instruments to assess EoE-specific QoL (EoO-QoL-A) and symptom severity (adult EoE activity index patient-reported outcome) and then underwent esophagogastroduodenoscopy with biopsy sampling. Physicians reported standardised information on EoE-associated endoscopic and histological alterations. The Spearman's rank correlation coefficient was calculated to determine the relationship between QoL and symptom severity. Linear regression and analysis of variance was used to quantify the extent to which variations in severity of EoE symptoms, endoscopic and histological findings explain variations in QoL.

RESULTS

Quality of life strongly correlated with symptom severity (r = 0.610, P < 0.001). While the variation in severity of symptoms, endoscopic and histological findings alone explained 38%, 35% and 22% of the variability in EoE-related QoL, respectively, these together explained 60% of variation. Symptom severity explained 18-35% of the variation in each of the five QoL subscale scores.

CONCLUSIONS

Eosinophilic oesophagitis symptom severity and biological disease activity determine QoL in adult patients with eosinophilic oesophagitis. Therefore, reduction in both eosinophilic oesophagitis symptoms as well as biological disease activity is essential for improvement of QoL in adult patients. Clinicaltrials.gov number, NCT00939263.

Pediatric and adult eosinophilic esophagitis: similarities and differences

Early in the 1990s, several case series described adults suffering from dysphagia and children with refractory reflux symptoms, both accompanied by an eosinophil-predominant infiltration, thereby conclusively distinguishing it from gastroesophageal reflux disease. Eosinophilic esophagitis (EoE) was recognized as its own entity in the adult and in the pediatric literature. In the last decade, evidence has accumulated that EoE represents a T-helper (Th)2-type inflammatory disease. Remodeling of the esophagus is a hallmark of EoE, leading to esophageal dysfunction and bolus impaction. Familial occurrence and disease association with single-nucleotide polymorphisms underscore the influence of genetics in this disease. Eosinophilic esophagitis may affect individuals at any age, although the clinical presentation is highly age dependent. There is a significant allergic bias in the EoE population, with the majority of patients having concurrent allergic rhinitis, asthma, eczema, and/or a history of atopy. One noteworthy difference is that in children, EoE seems to be primarily a food antigen-driven disease, whereas in adults, mainly aeroallergen sensitization has been observed. Treatment modalities for EoE include the 3Ds: drugs, diet, and dilation. The crucial question of whether adult and pediatric EoE are different phenotypes of one single entity or whether we are confronted with two different diseases is still open. Here, we review similarities and differences between EoE in adults and children.

FGF9-induced proliferative response to eosinophilic inflammation in oesophagitis

BACKGROUND

Oesophagitis is characterised by basal cell hyperplasia and activated eosinophils, which release mediators including major basic protein (MBP). MBP and its mimetic polyarginine activate the calcium sensing receptor (CaSR) on oesophageal epithelium. Fibroblast growth factor 9 (FGF9) is implicated in epithelial homeostasis and proliferative response to injury, but has not been characterised in the oesophagus.

OBJECTIVE

To characterise FGF9 in oesophageal epithelium and oesophagitis, as the result of MBP activation of the CaSR.

METHODS

Human oesophageal epithelial cells (HET-1A) were used to compare affects of calcium, polyarginine and MBP-peptide on FGF9. HET-1A were transfected with interfering RNA (siRNA(CaSR)). FGF9, FGF receptors 2 and 3, bone morphogenetic protein (BMP)-2, BMP-4 and noggin mRNA expression were detected by reverse transcriptase polymerase chain reaction. FGF9 was measured from HET-1A and from normal, gastro-oesophageal reflux and eosinophilic oesophagitis (EoE) patient biopsies using ELISA and immunohistochemistry. HET-1A proliferation was studied using bromodeoxyuridine and MTT.

RESULTS

FGF9 was secreted by HET-1A cells treated with polyarginine and MBP-peptide, but not calcium. This effect was abrogated by siRNA(CaSR). FGF9 receptor mRNA was present. HET-1A cells proliferated following rhFGF9, but not MBP-peptide treatment, and rhFGF9 altered transcription of downstream proliferation-related genes (noggin, BMP-2 and BMP-4). FGF9 was increased in biopsies from patients with eosinophilic oesophagitis, which correlated with basal hyperplasia.

CONCLUSION

Eosinophil-released MBP acts on the CaSR to increase FGF9 in oesophageal epithelial cells, leading to proliferation. Increased FGF9 is found in biopsies of EoE patients and may play a role in the pathogenesis of oesophagitis.

Review article: the pathogenesis and management of eosinophilic oesophagitis

BACKGROUND

Eosinophilic oesophagitis is a clinicopathological disease affecting both children and adults that is characterized by symptoms of gastro-oesophageal reflux disease (feeding refusal, vomiting, heartburn, dysphagia and food impaction) and dense oesophageal eosinophilia both of which are unresponsive to proton pump inhibition.

AIM

To present a review of the recent literature examining the pathogenesis and treatments of eosinophilic oesophagitis.

METHODS

We performed a PubMed search for eosinophilic oesophagitis, pathogenesis and treatments.

RESULTS

Translational and basic studies suggest that this disease is sparked by food or by aeroallergens. To date, effective treatments include systemic/topical corticosteroids, specific food elimination or an elemental diet. While several studies identified oesophageal strictures as potential complications of unbridled eosinophilia, the natural history of the disease is still not certain. Recent studies suggest a role for interleukin-5 and eotaxin-3 in the pathogenesis of eosinophilic oesophagitis and suggest an impact of future targeted therapeutic agents.

CONCLUSIONS

Eosinophilic oesophagitis represents a immune-mediated disease of undetermined pathogenesis. While many patients develop clinicopathological findings following ingestion of foods, others do not. Natural history studies will be critical to defining future treatment paradigms.

Clinicopathologic features of esophagitis in children

The esophagus traditionally has been considered a simple conduit for more than 50 tons of foodstuffs ingested during a lifetime. A growing body of literature, however, is defining the dynamic role of esophageal protective mechanisms and is identifying the immunologic milieu present within the squamous mucosa. When the innate protective mechanisms are overcome by an injurious agent, an inflammatory process ensues, and the clinicopathologic features of esophagitis are manifest. This article focuses on features of several causes of esophagitis in children, including peptic disease, duodenogastroesophageal reflux, Crohn's disease, and infection. In addition, a relatively new, but increasingly recognized, entity-eosinophilic esophagitis-is highlighted.

Phosphorylation-dependent targeting of cAMP response element binding protein to the ubiquitin/proteasome pathway in hypoxia

Hypoxia activates a number of gene products through degradation of the transcriptional coactivator cAMP response element binding protein (CREB). Other transcriptional regulators (e.g., beta-catenin and NF-kappa B) are controlled through phosphorylation-targeted proteasomal degradation, and thus, we hypothesized a similar degradative pathway for CREB. Differential display analysis of mRNA derived from hypoxic epithelia revealed a specific and time-dependent repression of protein phosphatase 1 (PP1), a serine phosphatase important in CREB dephosphorylation. Subsequent studies identified a previously unappreciated proteasomal-targeting motif within the primary structure of CREB (DSVTDS), which functions as a substrate for PP1. Ambient hypoxia resulted in temporally sequential CREB serine phosphorylation, ubiquitination, and degradation (in vitro and in vivo). HIV-tat peptide-facilitated loading of intact epithelia with phosphopeptides corresponding to this proteasome targeting motif resulted in inhibition of CREB ubiquitination. Further studies revealed that PP1 inhibitors mimicked hypoxia-induced gene expression, whereas proteasome inhibitors reversed the hypoxic phenotype. Thus, hypoxia establishes conditions that target CREB to proteasomal degradation. These studies may provide unique insight into a general mechanism of transcriptional regulation by hypoxia.

Eosinophil granule-derived major basic protein induces IL-8 expression in human intestinal myofibroblasts

Eosinophil infiltration occurs in a variety of allergic and inflammatory diseases. The release of preformed mediators from eosinophils may contribute to inflammatory responses. We investigated the ability of eosinophil-derived major basic protein and eosinophil-derived neurotoxin to stimulate production of IL-8 from intestinal myofibroblasts. Intestinal myofibroblasts (18-Co cells) were incubated with major basic protein, eosinophil-derived neurotoxin, or a synthetic analogue of major basic protein, poly-L-arginine. Immunoreactive IL-8 was measured by ELISA and IL-8 mRNA levels were analysed by Northern blot or reverse transcription-polymerase chain assay. Major basic protein induced IL-8 mRNA production and release of significant levels of IL-8 immunoreactive protein. By contrast, eosinophil-derived neurotoxin stimulated little IL-8 release. The induction of IL-8 mRNA by poly-L-arginine was significantly inhibited by actinomycin D. These findings demonstrate a novel interaction between eosinophils and intestinal fibroblasts that may be involved in the pathogenesis of diseases associated with tissue eosinophilia.

Parallel induction of epithelial surface-associated chemokine and proteoglycan by cellular hypoxia: implications for neutrophil activation

Neutrophil-induced damage to the protective epithelium has been implicated in mucosal disorders associated with hypoxia, and such damage may be initiated by epithelial-derived chemokines. Because chemokines can bind to membrane proteoglycans, we hypothesized that chemokines may associate with epithelial surfaces and activate polymorphonuclear neutrophils (PMN). Epithelial hypoxia (pO2 20 torr) resulted in a time-dependent induction of interleukin-8 (IL-8) mRNA, soluble protein, as well as surface protein. Such surface IL-8 expression was demonstrated to be dependent on heparinase III expression, and extensions of these experiments indicated that hypoxia induces epithelial perlecan expression in parallel with IL-8. Finally, co-incubation of post-hypoxic epithelia with human PMN induced IL-8-dependent expression of the PMN beta2-integrin CD11b/18. These data indicate that chemokines liberated from epithelia may exist in a surface-bound, bioactive form and that hypoxia may regulate proteoglycan expression.

Ligation of intestinal epithelial CD1d induces bioactive IL-10: critical role of the cytoplasmic tail in autocrine signaling

The intestinal epithelium is anatomically positioned to serve as the critical interface between the lumen and the mucosal immune system. In addition to MHC class I and II antigens, intestinal epithelia constitutively express the nonclassical MHC molecule CD1d, a transmembrane molecule with a short cytoplasmic tail expressed as a beta(2)-microglobulin-associated 48-kDa glycoprotein and novel beta(2)-microglobulin-independent 37-kDa nonglycosylated protein on intestinal epithelia. At present, it is not known whether extracellular ligands can signal intestinal epithelial CD1d. To define signaling of CD1d cytoplasmic tail, retrovirus-mediated gene transfer was used to generate stable cell lines expressing wild-type CD1d or a chimeric molecule (extracellular CD1d and cytoplasmic CD1a), and surface CD1d was triggered by antibody crosslinking. Although wild-type CD1d was readily activated (tyrosine phosphorylation), no demonstrable signal was evident in cell lines expressing the chimeric molecule. Subsequent studies revealed that anti-CD1d crosslinking specifically induces epithelial IL-10 mRNA and protein and is blocked by the tyrosine kinase inhibitor genistein. Further studies addressing epithelial-derived IL-10 revealed that anti-CD1d crosslinking attenuates IFN-gamma signaling and that such attenuation is reversed by addition of functionally inhibitory IL-10 antibodies. These results define signaling through surface CD1d, and, importantly, they demonstrate that this pathway may serve to dampen epithelial proinflammatory signals.

Mast cells contribute to PACAP-induced dermal oedema in mice

In the present study the effect of intradermal PACAP-injection on dermal oedema in mice was investigated and the contribution of mast cells to this response was assessed. The injection of PACAP 1-38 into the ears of C57BL/6 mice evoked a dose-dependent response, which, after higher doses of PACAP 1-38, lasted at least 24 h. Histological examination showed significant mast cell degranulation induced by PACAP. Using mast cell-deficient WBB6F1-Kit(W)/Kit(W-v) mice and the congenic mice, we demonstrated that the the early phase (30 min to 6 h) of PACAP-induced ear swelling response was significantly diminished in mast cell-deficient mice, suggesting that mast cell degranulation contributes to this phase of the response. When mast cell-deficient WBB6F1-Kit(W)/Kit(W-v) mice were locally and selectively reconstituted by adoptive mast cell transfer, the dermal oedema was almost equal to that of control animals in the early phase of PACAP injection. These results show that mast cell degranulation contributes to PACAP-induced dermal oedema in mice.

Allergic esophagitis in children: a clinicopathological entity

Infiltration of esophageal epithelium by eosinophils is seen in reflux esophagitis and allergic gastroenteritis. This study was performed to identify differences between patients with acid reflux esophagitis and those with non-acid reflux, possibly allergic, esophagitis. Intraepithelial eosinophils were demonstrated in posttherapy esophageal biopsy specimens in 28 children treated for gastroesophageal reflux disease (GERD). These patients were divided into three groups based on their response to treatment and the results of esophageal pH probe monitoring. Eleven patients (Group A) had incomplete clinical response and normal pH probe monitoring results. Ten patients (Group B) had incomplete response but did not have pH probe monitoring. These two groups formed the index population. Seven patients (Group C) had clinical improvement with GERD therapy and abnormal pH probe monitoring characteristic of GERD; they constituted the control population. Clinical, laboratory, and pathologic features were evaluated to detect differences between index and control populations. Dysphagia, food impaction, failure to thrive, peripheral eosinophilia, and abnormal allergen skin test results were detected only in Group A and B patients. Biopsy specimens of the distal 9 cm of the esophagus, after GERD therapy, contained larger numbers of eosinophils in Groups A and B than in Group C as shown on high-power fields (HPF) (A: 31/HPF +/- 19.5; B: 28/HPF +/-23.7; versus C: 5/HPF +/-6.7; p = 0.009). Eosinophil aggregates were identified only in Groups A and B (p = 0.07). Eosinophils located preferentially in the superficial layers of the squamous epithelium were noted only in Groups A and B (p = 0.02). Group A and B patients demonstrated clinical improvement when given antiallergic therapy. The authors identified a group of pediatric patients characterized by an allergic history, lack of adequate response to GERD therapy, normal esophageal pH probe monitoring results, and large numbers of eosinophils in esophageal biopsy specimens obtained after GERD treatment. On the basis of these features, the authors propose that these patients represent examples of allergic esophagitis.

Early onset of nephrotic syndrome after treatment with D-penicillamine in a patient with Wilson's disease

Wilson's disease responds to a variety of treatments including D-penicillamine and trientene. Nephrotic syndrome is a late complication of D-penicillamine treatment. We report a pediatric patient with Wilson's disease who developed nephrotic syndrome 2 wk after beginning D-penicillamine. His nephrosis resolved and his disease is quiescent with trientene treatment.

Gastric inflammation during systemic anaphylaxis: neutrophil recruitment in stomach wall of mice does not require mast cell participation

We determined whether neutrophil infiltration into the stomach wall occurred during systemic anaphylaxis in mice and assessed the participation of mast cells in the response. Normal mice sensitized and challenged with antigen exhibited significant neutrophil infiltration in the gastric mucosa and submucosa compared with saline-challenged mice. The development of clinical signs of anaphylaxis and extent of gastric neutrophil infiltration was similar in mast cell-deficient Kit(W)/Kit(W-v) or Mgf(Sl)/Mgf(Sl-d) mice and the respective normal congenic mice. Pretreatment with sodium cromoglycate prevented the clinical signs of anaphylaxis and significantly diminished the infiltration of neutrophils in +/+ or Kit(W)/Kit(W-v) mice. Systemic anaphylaxis is associated with neutrophil infiltration into the stomach wall in mice, and mast cells are not required for the development of either the clinical manifestations or gastric neutrophil infiltration observed in the response.

Stem cell factor influences mast cell mediator release in response to eosinophil-derived granule major basic protein

Stem cell factor (SCF) is an important mast cell growth, differentiation, and survival factor. We investigated whether SCF influenced the response of mouse mast cells to an IgE-independent stimulus, eosinophil-derived granule major basic protein (MBP). Mouse bone marrow cultured mast cells (BMCMC) were derived in either concanavalin-stimulated mouse spleen conditioned medium (CM) or SCF. The cloned growth, factor-independent mast cell line Cl.MC/C57.1 was also studied. BMCMC in SCF exhibited cytochemical staining properties, protease and histamine content, and increased serotonin uptake consistent with more mature differentiated mast cells as compared with BMCMC in CM or Cl.MC/ C57.1 cells. BMCMC in SCF released serotonin, 14C-labeled arachidonic acid metabolites and tumor necrosis factor-alpha (TNF-alpha) on stimulation with MBP, while no response was seen from either BMCMC in CM or Cl.MC/C57.1 cells. All three mast cell populations released mediators on stimulation with the cationic MBP analog, poly-L-arginine, indicating that the cationic charge did not explain the selective response of BMCMC in SCF to eosinophil-derived granule MBP. These findings show that SCF significantly influences mast cell differentiation and the responsiveness of mast cells to eosinophil-derived granule MBP.

Mast cell-dependent tumor necrosis factor alpha production participates in allergic gastric inflammation in mice

BACKGROUND & AIMS

Immunoglobulin E-dependent gastric inflammation is characterized by neutrophil infiltration, and mast cells are required for this response. The aim of this study was to examine whether mast cell production of tumor necrosis factor (TNF)-alpha participates in the recruitment of neutrophils during this response.

METHODS

The levels of TNF-alpha messenger RNA (mRNA) and protein in gastric tissues were assessed by Northern blot analysis and enzyme-linked immunosorbent assay. In situ hybridization and histochemical staining were performed to identify the cells expressing TNF-alpha transcripts. Anti-TNF-alpha antibodies or cyclosporine A were used in an attempt to inhibit neutrophil infiltration.

RESULTS

TNF-alpha mRNA and protein were increased in gastric tissues undergoing immunoglobulin E-dependent inflammation. Mast cells were required for the development of cells expressing TNF-alpha transcripts in the stomach. Seventy-nine percent of the cells in the mucosa and 100% of the cells in the submucosa expressing TNF-alpha mRNA were identified as mast cells. Anti-TNF-alpha antibodies inhibited neutrophil infiltration in the submucosa, and cyclosporine A inhibited the tissue expression of TNF-alpha mRNA and the influx of neutrophils into the submucosa and muscularis propria.

CONCLUSIONS

These findings show that mast cell-derived TNF-alpha is at least one of the mediators involved in the recruitment of neutrophils during immunoglobulin E-dependent gastric inflammation in the mouse.

The regulation of tumor necrosis factor-alpha production in murine mast cells: pentoxifylline or dexamethasone inhibits IgE-dependent production of TNF-alpha by distinct mechanisms

Mast cells activated via high-affinity receptors for IgE can produce a variety of multifunctional cytokines, including TNF-alpha, which is thought to be involved in the pathophysiology of allergic diseases and other inflammatory disorders. We investigated the regulation of Fc Fc epsilon RI-dependent TNF-alpha production by mouse mast cells using dexamethasone and pentoxifylline, pharmacological agents which are known to suppress TNF-alpha production by macrophages. We now report that either dexamethasone or pentoxifylline can inhibit IgE-dependent mouse mast cell production of TNF-alpha; however, the major site of action of these agents was different. Pentoxifylline inhibited mast cell TNF-alpha gene transcription, while dexamethasone inhibited TNF-alpha production predominantly by a post-transcriptional mechanism. These results demonstrate that the synthesis of mast cell TNF-alpha can be regulated pharmacologically at either the transcriptional or the translational level and that pentoxifylline and dexamethasone, two agents that are used to treat inflammatory disorders, can modulate mast cell TNF-alpha production at different points in the synthetic pathway of this cytokine.

Mast cell-dependent neutrophil and mononuclear cell recruitment in immunoglobulin E-induced gastric reactions in mice

BACKGROUND & AIMS

Immunoglobulin (Ig) E-dependent reactions elicit an immediate response and can also result in a late-phase reaction that is characterized by the infiltration of leukocytes. This study assessed whether IgE-dependent late-phase responses can be elicited in the stomach wall of mice and examined the role of mast cells in this reaction.

METHODS

IgE-dependent gastric inflammation was elicited in genetically mast cell-deficient KitW/KitW-v mice, the congenic normal (+/+) mice, and mast cell-deficient KitW/KitW-v mice that had undergone local and selective reconstitution of gastric mast cell populations.

RESULTS

IgE-dependent gastric reactions were associated with mast cell degranulation and the infiltration of both neutrophils and mononuclear cells in normal mice, but no significant leukocyte infiltration was observed in mast cell-deficient KitW/KitW-v mice. By contrast, in mast cell-reconstituted KitW/KitW-v mice, IgE-dependent reactions were associated with the infiltration of neutrophils and mononuclear cells.

CONCLUSIONS

These results show that late-phase reactions can occur during IgE-dependent gastric inflammation in the mouse and that the infiltration of both neutrophils and mononuclear cells that are observed during this reaction are mast cell dependent.

Dexamethasone and cyclosporin A suppress mast cell-leukocyte cytokine cascades by multiple mechanisms

Based on in vitro findings with mouse mast cells and in vivo findings in mice, we report that dexamethasone or cyclosporin A can have at least three actions which interfere with the pathogenesis IgE-, mast-cell-, and cytokine-dependent inflammatory reactions: suppression of the IgE-dependent increase in tumor necrosis factor (TNF)-alpha mRNA by mast cells, inhibition of the IgE-dependent production of TNF-alpha protein by mast cells, and diminution of the responsiveness of target cells to TNF-alpha. Our findings in mice raise the possibility that similar actions of these agents in humans may account for some of the clinical efficacy of corticosteroids and cyclosporin A in allergic diseases.

Dexamethasone or cyclosporin A suppress mast cell-leukocyte cytokine cascades. Multiple mechanisms of inhibition of IgE- and mast cell-dependent cutaneous inflammation in the mouse

In allergic diseases, exposure of sensitized subjects to allergen induces the activation of tissue mast cells that results in an immediate-type hypersensitivity response and, in some individuals, a a late phase response. We previously have reported that the neutrophil infiltration associated with IgE-dependent cutaneous inflammation in mice is mast cell-dependent and that TNF-alpha contributes significantly to this response. We report here that either dexamethasone or cyclosporin A can inhibit mouse mast cell TNF-alpha production in vitro, and that these agents also can significantly suppress the tissue swelling and leukocyte infiltration associated with two forms of TNF-alpha-associated inflammation in vivo: the entirely IgE- and mast cell-dependent inflammation at sites of passive cutaneous anaphylaxis reactions and the entirely TNF-alpha-dependent inflammation that is elicited by the direct intradermal injection of recombinant mouse TNF-alpha. Taken together, our in vitro and in vivo findings in mice indicate that dexamethasone or cyclosporin A can have at least three actions that interfere with the pathogenesis of IgE, mast cell, and cytokine-dependent inflammatory reactions:suppression of the IgE-dependent increase in TNF-alpha mRNA by mast cells, inhibition of the IgE-dependent production of TNF-alpha protein by mast cells, and diminution of the responsiveness of target cells to TNF-alpha. Our findings in mice raise the possibility that similar actions of these agents in humans may account for some of the clinical efficacy of corticosteroids and cyclosporin A in allergic diseases.

Dexamethasone or cyclosporin A suppress mast cell-leukocyte cytokine cascades. Multiple mechanisms of inhibition of IgE- and mast cell-dependent cutaneous inflammation in the mouse

In allergic diseases, exposure of sensitized subjects to allergen induces the activation of tissue mast cells that results in an immediate-type hypersensitivity response and, in some individuals, a a late phase response. We previously have reported that the neutrophil infiltration associated with IgE-dependent cutaneous inflammation in mice is mast cell-dependent and that TNF-alpha contributes significantly to this response. We report here that either dexamethasone or cyclosporin A can inhibit mouse mast cell TNF-alpha production in vitro, and that these agents also can significantly suppress the tissue swelling and leukocyte infiltration associated with two forms of TNF-alpha-associated inflammation in vivo: the entirely IgE- and mast cell-dependent inflammation at sites of passive cutaneous anaphylaxis reactions and the entirely TNF-alpha-dependent inflammation that is elicited by the direct intradermal injection of recombinant mouse TNF-alpha. Taken together, our in vitro and in vivo findings in mice indicate that dexamethasone or cyclosporin A can have at least three actions that interfere with the pathogenesis of IgE, mast cell, and cytokine-dependent inflammatory reactions:suppression of the IgE-dependent increase in TNF-alpha mRNA by mast cells, inhibition of the IgE-dependent production of TNF-alpha protein by mast cells, and diminution of the responsiveness of target cells to TNF-alpha. Our findings in mice raise the possibility that similar actions of these agents in humans may account for some of the clinical efficacy of corticosteroids and cyclosporin A in allergic diseases.

Intussusception and leiomyosarcoma of the gastrointestinal tract in a pediatric patient. Case report and review of the literature

Intestinal leiomyosarcoma is a rare tumor in infants and children; only 46 cases have been reported in the English literature. Presenting signs and symptoms include abdominal pain and gastrointestinal obstruction and bleeding. We describe a neonate with the unique presentation of ileocecal intussusception accompanying an ileal leiomyosarcoma. In contrast to adult patients, where intussusception is associated with smooth muscle tumors in 30% of cases, leiomyosarcoma and subsequent intussusception is rare in infancy and childhood. The overall prognosis for long-term survival is similar for both pediatric and adult patients with leiomyosarcoma of the intestinal tract, with a five-year survival in reported cases of 53% and 40%, respectively.

Variation in phenotypic expression of the Opa outer membrane protein and lipooligosaccharide of Neisseria meningitidis serogroup C causing periorbital cellulitis and bacteremia

Expression of the Opa outer membrane protein varies widely among isolates of Neisseria meningitidis; the clinical significance of this variation is unclear. A sialic-acid acceptor is present in the lipooligosaccharide of some strains of Neisseria and has been shown to render Neisseria gonorrhoeae serum-resistant. We report the case of a patient who had an unusual clinical manifestation of infection due to N. meningitidis serogroup C, periorbital cellulitis with concomitant bacteremia. Clinical isolates from the blood and aspirate of the periorbital cellulitis were identical except for the phenotypic expression of the Opa outer membrane protein in the isolate from the periorbital cellulitis and in the lipooligosaccharide phenotype of the sialic-acid acceptor as defined by monoclonal antibodies. We discuss the laboratory and clinical implications of these findings.

Colonic interposition after esophagogastrectomy in a child with Zollinger-Ellison syndrome

Zollinger-Ellison syndrome is a rare childhood entity that usually presents with peptic ulcer disease and is resistant to medical management. In contrast to the treatment of the disease in adults, total gastrectomy is the procedure of choice for pediatric patients. We report on a child with Zollinger-Ellison syndrome complicated by esophageal stricture in whom we performed a new operative procedure using a colonic interposition. The use of the procedure has obviated the side effects commonly associated with gastrectomy.

Cystic fibrosis--an otolaryngologic perspective

Cystic fibrosis (CF) is the most common lethal genetic disorder in white patients. The protean manifestations of the disease result from exocrine gland dysfunction and include chronically debilitating pulmonary and pancreatic compromise and clinically inconsequential (although diagnostically extremely important) sweat electrolyte abnormalities. The subject of this article is the otolaryngologic manifestations of the disease, based on a retrospective analysis of 450 cases. Nasal polyposis and sinusitis occurred in 10% and 11% of patients, respectively, and polypectomy was, after laparotomy, the most common surgical procedure these children underwent. The extent of intranasal surgery for polyposis was found to be inversely proportional to the recurrence rate. A simple polypectomy was relatively ineffective treatment; when performed in conjunction with a Caldwell-Luc and either an intranasal or extranasal ethmoidectomy, the recurrence rate was less than 13%. Otologic problems, found in 8% of patients, included chronic otitis media (2.5%) and acute otitis media (5.5%). Only five patients required pressure-equalizing tubes. Recent genetic advances of immense importance are also described. Although the basic gene defect has yet to be elucidated, by use of a technique known as restriction-fragment-linked polymorphism, the gene associated with CF has been found in the middle of the long arm of chromosome 7. By following gene markers closely associated with this gene, it is possible to do carrier tests within affected families and, if certain criteria are met, perform prenatal diagnosis. Eventual isolation and characterization of the gene will follow, hopefully making prevention possible and treatment more effective.