Gut endocrine cell population in coeliac disease estimated by immunocytochemistry using a monoclonal antibody to chromogranin

Enteroendocrine cells regulate intestinal homeostasis and epithelial function

Enteroendocrine cells (EECs) are well-known for their systemic hormonal effects, especially in the regulation of appetite and glycemia. Much less is known about how the products made by EECs regulate their local environment within the intestine. Here, we focus on paracrine interactions between EECs and other intestinal cells as they regulate three essential aspects of intestinal homeostasis and physiology: 1) intestinal stem cell function and proliferation; 2) nutrient absorption; and 3) mucosal barrier function. We also discuss the ability of EECs to express multiple hormones, describe in vitro and in vivo models to study EECs, and consider how EECs are altered in GI disease.

Celiac Disease and Gallbladder: Pathophysiological Aspects and Clinical Issues

Background: Celiac Disease (CD) is an immune-mediated disorder which primarily affects the small intestine; however, extra-intestinal organs are often affected by the pathological process, too. As regards the digestive system, liver alterations in CD patients have been widely described, which can also extend to the biliary tract. Notably, gallbladder function can be altered in CD patients. In this review, we specifically analyze and summarize the main pathophysiological aspects and clinical evidence of gallbladder dysfunction in CD patients, in order to discuss the potential medical complications and clinical research gaps. In addition to some perturbations of bile composition, CD patients can develop gallbladder dysmotility, which mainly expresses with an impaired emptying during the digestive phase. The main pathophysiological determinant is a perturbation of cholecystokinin secretion by the specific duodenal enteroendocrine cells in response to the appropriate nutrient stimulation in CD patients. This situation appears to be reversible with a gluten-free diet in most cases. Despite this gallbladder impairment, CD patients do not seem to be more predisposed to gallbladder complications, such as calculous and acalculous cholecystitis. However, very few clinical studies have actively investigated these clinical aspects, which may not be completely evidenced so far; alternatively, the substantial improvements in the last two decades regarding CD diagnosis, which have reduced the diagnostic delay (and related dietary treatment), may have lessened the potential clinical consequences of CD-related gallbladder dysfunction. Specific clinical studies focused on these aspects are needed for a better understanding of the clinical implications of gallbladder alterations in CD patients.

Gallstone Frequency in Children With Celiac Disease

Introduction

Celiac disease (CD) is a chronic autoimmune systemic disease caused by the T cell-driven immune mechanism, which is triggered by gluten in cereals such as wheat, barley, and rye in individuals who have a genetic predisposition. The purpose of the present study was to investigate the frequency of gallstones in children with CD.

Methods

A total of 120 patients who were diagnosed with CD and who were followed-up by the pediatric gastroenterology clinic of the hospital and 100 healthy children were included in the study. The age, gender, hemogram, biochemistry, and abdominal ultrasonography images of the patients were compared. Cases that had gallstones were evaluated in terms of fasting serum lipids, glucose-6-P dehydrogenase, and pyruvate kinase, osmotic fragility, hemoglobin electrophoresis, and peripheral smears. Cases diagnosed with a hematological or metabolic disease were excluded from the study. Celiac serology was examined in terms of CD diagnosis in cases who had gallstones for the first time.

Results

The median age of the patients with CD who were included in the study was eight years (5-12), and the median age of the control group was 10 years (6-13). A total of 48% of the Control Group was female, and 52% were male. No significant differences were detected between the age and gender distribution of the cases. There were no differences between hemogram and biochemical parameters. Gallstones were detected in six (5%) of CD-diagnosed cases, and in three (3%) of the cases in the control group. Two (2/160; 1.3%) of the patients who were referred to our clinic with the diagnosis of gallstones were diagnosed with CD.

Conclusions: Early diagnosis and treatment of CD is important to avoid gallstone development because a gluten-free diet corrects enteropathy significantly in CD. CD must be considered in cases with gallstones.

Increasing Evidence That Irritable Bowel Syndrome and Functional Gastrointestinal Disorders Have a Microbial Pathogenesis

The human gastrointestinal tract harbors most of the microbial cells inhabiting the body, collectively known as the microbiota. These microbes have several implications for the maintenance of structural integrity of the gastrointestinal mucosal barrier, immunomodulation, metabolism of nutrients, and protection against pathogens. Dysfunctions in these mechanisms are linked to a range of conditions in the gastrointestinal tract, including functional gastrointestinal disorders, ranging from irritable bowel syndrome, to functional constipation and functional diarrhea. Irritable bowel syndrome is characterized by chronic abdominal pain with changes in bowel habit in the absence of morphological changes. Despite the high prevalence of irritable bowel syndrome in the global population, the mechanisms responsible for this condition are poorly understood. Although alterations in the gastrointestinal microbiota, low-grade inflammation and immune activation have been implicated in the pathophysiology of functional gastrointestinal disorders, there is inconsistency between studies and a lack of consensus on what the exact role of the microbiota is, and how changes to it relate to these conditions. The complex interplay between host factors, such as microbial dysbiosis, immune activation, impaired epithelial barrier function and motility, and environmental factors, including diet, will be considered in this narrative review of the pathophysiology of functional gastrointestinal disorders.

Poorly differentiated neuroendocrine rectal carcinoma with uncommon immune-histochemical features and clinical presentation with a subcutaneous metastasis, treated with first line intensive triplet chemotherapy plus bevacizumab FIr-B/FOx regimen: an experience of multidisciplinary management in clinical practice

Background

Neuroendocrine tumors (NETs) are heterogeneous, widely distributed tumors arising from neuroendocrine cells. Gastrointestinal (GI)-NETs are the most common and NETs of the rectum represent 15, 2% of gastrointestinal malignancies. Poorly differentiated neuroendocrine carcinomas of the GI tract are uncommon. We report a rare case of poorly differentiated locally advanced rectal neuroendocrine carcinoma with nodal and a subcutaneous metastasis, with a cytoplasmic staining positive for Synaptophysin and Thyroid Transcription Factor-1.

Case presentation

A 72-year-old male presented to hospital, due to lumbar, abdominal, perineal pain, and severe constipation. A whole-body computed tomography scan showed a mass of the right lateral wall of the rectum, determining significant reduction of lumen caliber. It also showed a subcutaneous metastasis of the posterior abdominal wall. Patient underwent a multidisciplinary evaluation, diagnostic and therapeutic plan was shared and defined. The pathological examination of rectal biopsy and subcutaneous nodule revealed features consistent with small-cell poorly differentiated neuroendocrine carcinoma. First line medical treatment with triplet chemotherapy and bevacizumab, according to FIr-B/FOx intensive regimen, administered for the first time in this young elderly patient affected by metastatic rectal NEC was highly active and tolerable, as previously reported in metastatic colo-rectal carcinoma (MCRC). A consistent rapid improvement in clinical conditions were observed during treatment. After 6 cycles of treatment, CT scan and endoscopic evaluation showed clinical complete response of rectal mass and lymph nodes; patient underwent curative surgery confirming the pathologic complete response at PFS 9 months.

Discussion and conclusions

This case report of a locally advanced rectal NEC with an unusual subcutaneous metastasis deserves further investigation of triplet chemotherapy-based intensive regimens in metastatic GEP NEC.

Simultaneous analyses of carbohydrate-mediated serum GLP-1 and GLP-2 and duodenal receptor expression in children with and without celiac disease

BACKGROUND

Variability in glucagon-like peptide (GLP)-1 and GLP-2 plasma concentrations has been suggested in Celiac disease (CD), with inconclusive results. We assessed the association between serum levels of GLP-1 and GLP-2 and their duodenal receptor expression in children with and without CD.

METHODS

This was a two-part, cross-sectional and prospective cohort study. Group assignment, performed after duodenal samples for mRNA expression of GLP-1 receptor (GLP1R) and GLP-2 receptor (GLP2R), were taken during esophagogastroduodenoscopy. The control group consisted of patients with normal endoscopy and negative serology. The CD group consisted of patients with positive serology and endoscopy suggestive of CD. All had an oral glucose-tolerance test (OGTT). CD patients underwent a second OGTT after 6 months of a gluten-free diet (GFD).

RESULTS

The CD group included 12 patients; 7 males with mean age 9.2 ± 2.5 years. The control group included 10 patients; 5 males with mean age 12 ± 4 years, (p = 0.14). No differences were detected in basal or peak levels of GLP-1 or GLP-2 between control, naïve CD (before GFD) and treated CD (after GFD) groups. Expression of GLP1R and GLP2R mRNA was similar. Significant positive correlations between glucose and C-peptide secretion (r = 0.9, p < 0.01) and GLP-1 and GLP-2 (r = 0.8, p = 0.01) were detected in the control group. Significant negative correlations were found in the naïve CD group between GLP2R expression and glucose secretion (r = -0.68, p = 0.015) and GLP1R expression and serum GLP-1 (r = -0.7, p = 0.016).

CONCLUSIONS

Although no significant differences were detected in secretion patterns or gut receptor expression of GLP-1 and GLP-2 in healthy versus CD pediatric patients, the detected discrepancy between the ligand levels and their tissue receptors requires additional study.

Impaired intestinal cholecystokinin secretion, a fascinating but overlooked link between coeliac disease and cholesterol gallstone disease

BACKGROUND

Coeliac disease is a chronic, small intestinal, immune-mediated enteropathy caused by a permanent intolerance to dietary gluten in genetically predisposed individuals. Clinical studies have found that intestinal cholecystokinin secretion and gallbladder emptying in response to a fatty meal are impaired before coeliac patients start the gluten-free diet (GFD).

DESIGN

However, it was never really appreciated whether coeliac disease is associated with gallstones because there were very few studies investigating the mechanism underlying the impact of coeliac disease on the pathogenesis of gallstones.

RESULTS

We summarize recent progress on the relationship between coeliac disease and gallstones and propose that coeliac disease is an important risk factor for gallstone formation because defective intestinal cholecystokinin secretion markedly increases susceptibility to cholesterol gallstones via a mechanism involving dysmotility of both the gallbladder and the small intestine. Because GFD can significantly improve the coeliac enteropathy, early diagnosis and therapy in coeliac patients is crucial for preventing the long-term impact of cholecystokinin deficiency on the biliary and intestinal consequences. When gluten is reintroduced, clinical and histologic relapse often occurs in coeliac patients. Moreover, some of the coeliac patients do not respond well to GFD.

CONCLUSIONS

It is imperative to routinely examine by ultrasonography whether gallbladder motility function is preserved in coeliac patients and monitor whether biliary sludge (a precursor of gallstones) appears in the gallbladder, regardless of whether they are under the GFD programme. To prevent gallstones in coeliac patients, it is urgently needed to investigate the prevalence and pathogenesis of gallstones in these patients.

Irritable Bowel Syndrome: Pathophysiology and Current Therapeutic Approaches

Irritable bowel syndrome (IBS) is a prevalent condition affecting 10-20% of adults in most countries; IBS results in significant morbidity and health care costs. IBS is a disorder of the brain-gut axis, and recent insights into the pathophysiological mechanisms include altered bile acid metabolism, neurohormonal regulation, immune dysfunction, alterations in the epithelial barrier, and secretory properties of the gut. There remains a significant unmet need for effective treatments, particularly for the pain component of IBS, although the introduction of drugs directed at secretion, motility, and a nonabsorbable antibiotic provides an option for the bowel dysfunction in IBS.

Lack of endogenous cholecystokinin promotes cholelithogenesis in mice

BACKGROUND

Celiac disease is an autoimmune enteropathy caused by a permanent intolerance to dietary gluten in genetically predisposed individuals. Cholecystokinin (CCK) release from the proximal small intestine and gallbladder emptying in response to a fatty meal are greatly reduced in celiac patients before they start the gluten-free diet, showing a genetic predisposition to gallstones.

METHODS

To elucidate the complex pathophysiological mechanisms determining the biliary characteristic of celiac disease, we investigated the effect of the absence of endogenous CCK on cholesterol crystallization and gallstone formation in mice fed a lithogenic diet for 28 days.

KEY RESULTS

Fasting gallbladder volumes were increased and the response of gallbladder emptying to the high-fat diet was impaired in CCK knockout (KO) mice compared to wild-type mice. Because of the absence of CCK, small intestinal transit time was prolonged and intestinal cholesterol absorption was increased. During 28 days of feeding, elevated biliary cholesterol concentrations and gallbladder stasis promoted the growth and agglomeration of solid cholesterol crystals into microlithiasis and stones. Thus, cholesterol crystallization and gallstone formation were accelerated in CCK KO mice. In contrast, daily intraperitoneal administration of CCK-8 reduced gallstone formation in CCK KO mice even on the lithogenic diet.

CONCLUSIONS & INFERENCES

The lack of endogenous CCK enhances susceptibility to gallstones by impairing gallbladder contractile function and small intestinal motility function. These findings show that celiac disease is an important risk factor for gallstone formation and the gallbladder motility function should be routinely examined by ultrasonography and gallbladder stasis should be prevented in celiac patients.

The relation between celiac disease, nonceliac gluten sensitivity and irritable bowel syndrome

Wheat products make a substantial contribution to the dietary intake of many people worldwide. Despite the many beneficial aspects of consuming wheat products, it is also responsible for several diseases such as celiac disease (CD), wheat allergy, and nonceliac gluten sensitivity (NCGS). CD and irritable bowel syndrome (IBS) patients have similar gastrointestinal symptoms, which can result in CD patients being misdiagnosed as having IBS. Therefore, CD should be excluded in IBS patients. A considerable proportion of CD patients suffer from IBS symptoms despite adherence to a gluten-free diet (GFD). The inflammation caused by gluten intake may not completely subside in some CD patients. It is not clear that gluten triggers the symptoms in NCGS, but there is compelling evidence that carbohydrates (fructans and galactans) in wheat does. It is likely that NCGS patients are a group of self-diagnosed IBS patients who self-treat by adhering to a GFD.

Coeliac-like duodenal pathology in orthotopic liver transplant patients on mycophenolic acid therapy

AIMS

Diarrhoea following orthotopic liver transplantation (OLT) is a significant clinical problem associated with mycophenolic acid (MPA). The histological injury pattern associated with MPA in the large bowel is well documented in the literature; however, that in the duodenum is less extensively documented. The aim of this study was to investigate the histological spectrum of duodenal injury specifically in symptomatic OLT patients on MPA, and to compare this with the spectrum in patients with coeliac disease and in normal controls.

METHODS AND RESULTS

We reviewed our pathology database for all duodenal biopsies from patients on the OLT list over a period of 19 years. Medical records, anti-tissue transglutaminase IgA serology and histology were reviewed. Of the 667 patients who underwent endoscopy, 127 had duodenal biopsies (152 biopsies). Of these, 87.5% were normal. Sixteen showed abnormal histology, and seven (43.8%) of these were on MPA at the time of biopsy. Significant features included coeliac-like changes (shortened villi and increased intraepithelial lymphocyte counts), and novel findings included increased endocrine cell counts, apoptotic counts and lamina propria eosinophil counts in comparison with normal duodenal biopsies.

CONCLUSIONS

Pathologists should be aware of the features of MPA-associated duodenal injury, including coeliac-like changes and increased apoptotic counts. In those with abnormal histology, discontinuation or a reduction in the dose of MPA should be discussed.

Physiological underpinnings of irritable bowel syndrome: neurohormonal mechanisms

The gastrointestinal tract is a vast neuroendocrine organ with extensive extrinsic and intrinsic neural circuits that interact to control its function. Circulating and paracrine hormones (amine and peptide) provide further control of secretory, absorptive, barrier, motor and sensory mechanisms that are essential to the digestion and assimilation of nutrients, and the transport and excretion of waste products. Specialized elements of the mucosa (including enteroendocrine cells, enterocytes and immune cells) and the microbiome interact with other intraluminal contents derived from the diet, and with endogenous chemicals that alter the gut's functions. The totality of these control mechanisms is often summarized as the brain-gut axis. In irritable bowel syndrome (IBS), which is the most common gastrointestinal disorder, there may be disturbances at one or more of these diverse control mechanisms. Patients present with abdominal pain in association with altered bowel function. This review documents advances in understanding the pathophysiological mechanisms in the brain-gut axis in patients with IBS. It is anticipated that identification of one or more disordered functions in clinical practice will usher in a renaissance in the management of IBS, leading to effective therapy tailored to the needs of the individual patient.

Increase in neuroendocrine cells in the duodenal mucosa of patients with refractory celiac disease

OBJECTIVES

Several immune-mediated gastrointestinal disorders, including celiac disease (CD), are associated with neuroendocrine cell hyperplasia. However, neuroendocrine cells have never been explored in refractory CD (RCD).

METHODS

Serial duodenal sections from 17 patients with RCD (6 type 1 and 11 type 2), 16 uncomplicated CD patients before and after gluten-free diet, 14 patients with potential CD, 27 patients with non-CD villous atrophy, i.e., common variable immunodeficiency (n=12), Whipple's disease (n=10) and giardiasis (n=5), and 16 healthy subjects were processed for the immunohistochemical detection of chromogranin A (CgA), serotonin, and somatostatin. Mucosal tryptophan hydroxylase (TpH)-1 and serotonin-selective reuptake transporter (SERT) transcripts were measured by quantitative reverse transcription-PCR. Serum CgA and 24-h urine 5-hydroxyindoleacetic acid (5-HIAA) were assessed. Biopsies from treated CD patients were cultured with serotonin or peptic tryptic digest of gliadin (PT-gliadin), and interferon (IFN)-γ was detected by ELISA in culture supernatants.

RESULTS

Epithelial cells positive for CgA and serotonin, but not somatostatin, were significantly increased in RCD. Raised mucosal transcripts of TpH-1, but not SERT, were found in RCD. On biopsies from treated CD patients, serotonin upregulated IFN-γ production at levels comparable to those induced by PT-gliadin. Serum CgA, but not urine 5-HIAA, was increased in RCD. No significant difference was found between RCD type 1 and type 2 in terms of neuroendocrine cells, mucosal TpH-1 transcripts, and serum CgA.

CONCLUSIONS

Serotonin-producing neuroendocrine cells are increased in RCD mucosa. IFN-γ upregulation induced by serotonin suggests that this monoamine may have a role in sustaining the local inflammatory response in CD.

Editorial: fecal granins in IBS: cause or indicator of intestinal or colonic irritation?

Ohman et al. report increased fecal granins in patients with irritable bowel syndrome (IBS). Several interesting questions arise from their observations. Are the granins a cause of the pathophysiology or phenotype in IBS? Is the elevation of granins specific to IBS? What is the cause of increased fecal granin levels? Can fecal granin levels be used to diagnose IBS? Are increased fecal granins an expression of intestinal or colonic irritation? This paper adds to the body of evidence suggesting there are gastrointestinal disturbances in IBS; understanding these disturbances may provide clues to its pathogenesis and optimize management.

The ghrelin-positive cells number is increased in duodenum in children with celiac disease

Ghrelin is predominately produced in the stomach, but new findings indicate that the intestinal wall is an important source of the hormone. In patients with shortbowel syndrome, reduction in the intestinal tissue resulted in a decrease in the circulating ghrelin levels. Since in celiac disease (CD) intestinal mucosa atrophy is the main finding, alterations in duodenal ghrelin-positive cell population can be expected. The aim of the study was to evaluate the density of ghrelin-positive cells in the duodenum of CD children and its relationship with body mass index (BMI) and clinical presentation. The study included 31 consecutive patients with newly diagnosed CD [BMI SD scores (BMISDS) -0.926+/-1.496]. The control group consisted of 21 children (BMISDS -0.517+/-1.186], diagnosed with growth retardation, anemia or abdominal pain. All the patients underwent endoscopy with biopsy samples taken from distal duodenum. Immunohistochemistry was performed using rabbit anti- ghrelin (human) antiserum. The number of ghrelin-positive cells in the duodenum was significantly higher in children with CD than in controls (14.82+/-11.12 vs 5.69+/-5.02, p<0.0013). The density of ghrelin-positive cells in the duodenum did not correlate with age, pubertal status, BMISDS or clinical presentation. In the duodenum of CD children, the number of ghrelin-positive cells is increased compared with the control patients. The population of ghrelin-positive cells in the duodenum does not simply reflect an altered mucosal morphology or failure to thrive but is under the influence of other conditions.

Intestinal endocrine cells in myotonic dystrophy: an immunocytochemical and computed image analytical study

OBJECTIVES

To study intestinal endocrine cell types in patients suffering from myotonic dystrophy (MD) and diarrhoea.

DESIGN

Comparative study between MD patients and matched controls.

SETTING

Departments of Medicine, Central Hospital, Boden, and University Hospital, Umeå, Sweden.

SUBJECTS

Ten patients with MD (four males and six females) and suffering from diarrhoea. Ten healthy volunteers served as controls for the duodenal study and 13 patients under investigation for rectal bleeding and with endoscopically normal mucosa were controls for the rectal study.

MEASUREMENTS

The duodenal and rectal endocrine cell types were identified by immunohistochemical investigation and quantified by computed image analysis.

RESULTS

The total endocrine cell area in the duodenum as demonstrated by chromogranin A-immunoreactivity was significantly increased in MD as compared with the controls (126 +/- 58 vs. 48 +/- 22 x 10(3) microns 2 mm-2 in crypts and 230 +/- 183 vs. 28 +/- 22 in villi, respectively, P < 0.01). The increase included all types of endocrine cells studied, namely those positive for serotonin, cholecystokinin (CCK)/gastrin, secretin, gastric inhibitory peptide (GIP) and somatostatin. In the rectum, the total endocrine cell area as determined by chromogranin A-immunoreactivity was also significantly increased, but there was no statistical difference between the controls and patients with respect to the area of serotonin-, peptide YY (PYY)-, pancreatic polypeptide (PP)- or somatostatin-immunoreactive cells.

CONCLUSIONS

The increase in endocrine cell area indicates a disturbed endocrine regulation of the gastrointestinal tract that may contribute to the development of gastrointestinal symptoms encountered in MD patients.

Pan-neuronal expression of chromogranin A in rat nervous system

Sensitive and specific in situ hybridization detection of CGA mRNA, and immunohistochemistry with an antibody recognizing the CGA(316-329) epitope within CGA and its proteolytic fragments were employed to determine whether or not CGA mRNA or protein expression are restricted to specific neuronal subpopulations within the central and peripheral nervous systems. Virtually all neurons in sympathetic, sensory, and parasympathetic ganglia examined, as well as enteric nervous system and spinal cord, expressed both CGA mRNA and the 316-329 (WE-14) CGA epitope. Chromogranin A expression was also ubiquitous within all telencephalic and diencephalic brain nuclei examined, including frontal cortex, striatum, and hippocampus. In addition, CGA mRNA was expressed in nonneuronal cells that appeared to be glia in dorsal root ganglion, spinal cord, and brain. In contrast to earlier reports, neuronal expression of CGA appears to be unrestricted within the central and peripheral nervous systems. Nonneuronal expression of CGA also occurs in the nervous system, albeit at levels much lower than in neuronal cells.

Synaptophysin and chromogranins/secretogranins--widespread constituents of distinct types of neuroendocrine vesicles and new tools in tumor diagnosis

Normal and neoplastic neuroendocrine (NE) cells have been identified for many years by morphological criteria only. With the advent of immunocytochemistry, antibodies against NE-specific polypeptides have been used to identify NE cells that had been missed by conventional techniques, thus improving the diagnosis of NE cells. In this review article we discuss (i) the biochemical, cell biological and molecular biological data obtained so far for two major types of NE markers, synaptophysin, which is characteristic of the small "transparent-looking" neurosecretory vesicles, and the chromogranins/secretogranins, which are widespread constituents of the larger "dense-cored" secretory granules; (ii) the immunohistochemical data obtained for these marker proteins in normal and neoplastic human NE cells and tissues; and (iii) future possible developments involving these as well as other proteins that are associated with these two distinct secretory organelles of NE cells and may serve as potential markers in NE cell diagnosis.

Are intestinal endocrine cells affected in Hirschsprung's disease? An immunohistochemical study with anti-Leu 7 monoclonal antibody

Specimens from 15 cases of Hirschsprung's disease and 22 control cases of normal guts were studied by the peroxidase-antiperoxidase (PAP) method with with anti-Leu 7 (Leu 7) monoclonal antibody (MAb). In the normal human gut, some satellite cells in the enteric plexuses and a few nerve fibers and ganglion cells in the intestinal wall were stained with Leu 7 MAb, while endocrine cells in the intestinal mucosa showed consistent and intense cytoplasmic Leu 7 positivity. In Hirschsprung's disease, the number of Leu 7-positive endocrine cells was significantly low. The mean value of the number of Leu 7-positive endocrine cells per one microscopic field (X300 magnification) was 4.6 +/- 0.6 (+/- SE) in controls and 0.7 +/- 0.3 (+/- SE) in Hirschsprung's disease (P less than .001 by Student's t test). Our findings suggest that the development of endocrine cells in the intestinal mucosa may be closely related to the development of ganglion cells in the enteric plexuses, and that the anti-Leu 7 MAb may be useful for the diagnosis of Hirschsprung's disease when biopsy specimens are limited to the mucosa only.

Prostanoids in jejunal biopsy specimens of celiac children with active disease and on challenge diet. Radioimmunologic evaluation

Prostanoid generation (prostaglandin E2 and thromboxane B2) in jejunal biopsy specimens from celiac patients was evaluated, comparing celiac patients with celiac patients on challenge diet and controls. Generation of prostaglandin E2 in jejunal specimens from 14 children with active celiac disease was significantly higher (341.8 +/- 82.3 ng/g; mean +/- SEM) than that from 7 celiac patients on gluten challenge diet (69.4 +/- 13.2 ng/g) or 8 normal children (92 +/- 23 ng/g) (p less than 0.05). In contrast, thromboxane B2 generation in jejunal specimens from all three groups did not show any statistically significant variation. Our results indicate that prostaglandin E2 generation is not merely related to the activity of clinical symptoms, since patients receiving gluten challenge had prostaglandin E2 levels that did not differ from those of controls.

Increased populations of endocrine cells in Crohn's ileitis

Hyperplasia of nerves has been described previously in Crohn's disease. To determine whether similar alteration of the enteric endocrine system occurs, endocrine cells of the ileal epithelium were quantified in typical cases of the disease. In the ileum from patients with Crohn's disease, there was an increase in the endocrine cell population, as visualised by immunostaining of chromogranin. Quantification of endocrine cell numbers showed significant increases in both macroscopically uninvolved (i.e. histologically normal) (35.0 +/- 3.8, cells per unit length of muscularis mucosae mean +/- SEM, P less than 0.05) and involved (44.5 +/- 5.5, P less than 0.01) Crohn's disease samples, compared with normal controls (23.7 +/- 3.4). Although individual types of endocrine cell showed slight increases in Crohn's samples, only the enterochromaffin cells in abnormal bowel showed a significantly greater population (normal controls 10.5 +/- 2.3; involved Crohn's 21.3 +/- 4.4, P less than 0.05).