Beyond Neutrophils for predicting relapse and remission in ulcerative colitis

BACKGROUND AND AIMS

This study examines colonic histologic features in ulcerative colitis (UC) in endoscopic remission to determine which cell types and biopsy sites best predict a patient's likelihood of remaining in remission.

METHODS

This is a retrospective chart, endoscopy and histology review of 166 persons with UC in endoscopic remission followed in a single IBD practice over a median of 6 years (range, 2-11 years). Clinical remission was based on global physician assessment and colonoscopy reports, and clinical relapse on chart review. Histologic features of previous injury and also number and location of plasma cells and eosinophils were assessed. We evaluated all semi-quantitatively using a standard set of illustrations for the grade to maintain consistency. Multiple logistic regression analysis and survival analysis were used to identify features associated with relapse.

RESULTS

Clinical relapse occurred in 44 persons. Ulceration, especially in the left colon. was highly predictive of relapse. In the absence of acute inflammation of ulceration, the variables most predictive of relapse were increased plasma cells in the basal 20% of the lamina propria, and eosinophils in the left colon. The variable most predictive of persistent remission was the presence of intraepithelial eosinophils whether in the surface epithelium or within crypts, especially in the right colon. Lamina propria eosinophils (grade>2) throughout the colon predicted relapse.

CONCLUSION

In the absence of neutrophils or ulceration, left-sided plasmacytosis in the basal 20% of the lamina propria and increased lamina propria eosinophils provide the best indicators of relapse in UC in clinical and endoscopic remission.

Improving tumor budding reporting in colorectal cancer: a Delphi consensus study

Tumor budding is a long-established independent adverse prognostic marker in colorectal cancer, yet methods for its assessment have varied widely. In an effort to standardize its reporting, a group of experts met in Bern, Switzerland, in 2016 to reach consensus on a single, international, evidence-based method for tumor budding assessment and reporting (International Tumor Budding Consensus Conference [ITBCC]). Tumor budding assessment using the ITBCC criteria has been validated in large cohorts of cancer patients and incorporated into several international colorectal cancer pathology and clinical guidelines. With the wider reporting of tumor budding, new issues have emerged that require further clarification. To better inform researchers and health-care professionals on these issues, an international group of experts in gastrointestinal pathology participated in a modified Delphi process to generate consensus and highlight areas requiring further research. This effort serves to re-affirm the importance of tumor budding in colorectal cancer and support its continued use in routine clinical practice.

Beyond Helicobacter: dealing with other variants of gastritis-an algorithmic approach

In daily practice, the presence of inflammation in gastric biopsies prompts a mental algorithm, an early question being whether the lesion present is Helicobacter-associated. If Helicobacter organisms are not found, then there is a further algorithm, governed by the predominant type of inflammatory cells present, and the presence of other features such as intraepithelial lymphocytosis, a subepithelial collagen band, granulomas, coexisting chronic inflammation, focality, and superimposed reactive changes including erosions and ulcers. Each of these generates its own differential diagnosis. If no inflammation is present, then the two major changes specifically looked for are the changes associated with hypergastrinaemia, by far the most common cause of which is treatment with proton pump inhibitors, and reactive changes. These may be present with and without accompanying inflammation, and, when the epithelial changes dominate, the term gastropathy is preferred. In this article, we present an approach to non-Helicobacter inflammation and gastropathies.

Appropriateness of using patient-derived xenograft models for pharmacologic evaluation of novel therapies for esophageal/gastro-esophageal junction cancers

The high morbidity and mortality of patients with esophageal (E) and gastro-esophageal junction (GEJ) cancers, warrants new pre-clinical models for drug testing. The utility of primary tumor xenografts (PTXGs) as pre-clinical models was assessed. Clinicopathological, immunohistochemical markers (p53, p16, Ki-67, Her-2/neu and EGFR), and global mRNA abundance profiles were evaluated to determine selection biases of samples implanted or engrafted, compared with the underlying population. Nine primary E/GEJ adenocarcinoma xenograft lines were further characterized for the spectrum and stability of gene/protein expression over passages. Seven primary esophageal adenocarcinoma xenograft lines were treated with individual or combination chemotherapy. Tumors that were implanted (n=55) in NOD/SCID mice had features suggestive of more aggressive biology than tumors that were never implanted (n=32). Of those implanted, 21/55 engrafted; engraftment was associated with poorly differentiated tumors (p=0.04) and older patients (p=0.01). Expression of immunohistochemical markers were similar between patient sample and corresponding xenograft. mRNA differences observed between patient tumors and first passage xenografts were largely due to loss of human stroma in xenografts. mRNA patterns of early vs late passage xenografts and of small vs large tumors of the same passage were similar. Complete resistance was present in 2/7 xenografts while the remaining tumors showed varying degrees of sensitivity, that remained constant across passages. Because of their ability to recapitulate primary tumor characteristics during engraftment and across serial passaging, PTXGs can be useful clinical systems for assessment of drug sensitivity of human E/GEJ cancers.

Canadian Association of Pathologists-Association canadienne des pathologistes National Standards Committee for High Complexity Testing/Immunohistochemistry: guidelines for the preparation, release, and storage of unstained archived diagnostic tissue sections for immunohistochemistry

OBJECTIVES

Formalin-fixed, paraffin-embedded unstained archived diagnostic tissue sections are frequently exchanged between clinical laboratories for immunohistochemical staining. The manner in which such sections are prepared represents a type of preanalytical variable that must be taken into account given the growing importance of immunohistochemical assays, especially predictive and prognostic tests, in personalized medicine.

METHODS

Recommendations were derived from review of the literature and expert consensus of the Canadian Association of Pathologists-Association canadienne des pathologists National Standards Committee for High Complexity Testing/Immunohistochemistry.

RESULTS

Relevant considerations include the type of glass slide on which to mount the unstained sections; the thickness of the tissue sections; the time from slide preparation to testing; the environment, particularly the temperature at which the unstained sections will be maintained prior to testing; the inclusion of on-slide positive control tissue where possible; and whether patient identifier(s) should be included on slide labels.

CONCLUSIONS

Clear communication between requesting and releasing laboratories will facilitate the proper preparation of unstained sections and also ensure that applicable privacy considerations are addressed.

Infection and esophageal cancer

The following, from the 12th OESO World Conference: Cancers of the Esophagus, includes commentaries on infection and cancer, and includes commentaries on the influence of bacterial infections on mucin expression and cancer risk; the role of esophageal bacterial biota in the incidence of esophageal disease; the association between human papilloma virus (HPV) and esophageal squamous cell carcinoma; the role of HPV in esophageal adenocarcinoma; the role of Helicobacter pylori in cardiac carcinoma; and the role of Epstein-Barr virus infection in esophageal cancer.

Peritoneal elastic lamina invasion: limitations in its use as a prognostic marker in stage II colorectal cancer

Peritoneal involvement in colorectal cancer (CRC) is an adverse prognostic feature, which may prompt consideration of adjuvant chemotherapy in stage II disease. Controversies and challenges surrounding its assessment have led to consideration of peritoneal elastic lamina invasion (ELI) as an alternative marker of advanced local spread. The objectives of this study were (1) to evaluate the prognostic significance of peritoneal ELI in stage II CRC and (2) to determine the feasibility of ELI assessment in routine practice with the use of an elastic stain. Two hundred seventeen patients with stage II CRC (186, pT3; 31, pT4) were assessed for ELI and other established adverse histologic features. Of the pT3 tumors, 31 (16.7%) were ELI positive, 121 (65%) were ELI negative, and 34 (18.3%) lacked an identifiable elastic lamina. There were no significant differences in disease-free survival between pT3 ELI-negative and ELI-positive tumors (P = .517). The disease-free survival of pT4 tumors was significantly lower than that of pT3 ELI-negative tumors (P = .024) and pT3 ELI-positive tumors (P = .026), respectively. The elastic lamina was detected less frequently in right-sided pT3 tumors compared with left-sided tumors (65/91 [71.4%] versus 87/95 [91.6%], P < .001). Right-sided tumors were also associated with a reduction in the staining intensity of the elastic lamina (P < .001). In conclusion, peritoneal ELI was not an adverse prognostic factor in this study. The frequent absence of an identifiable elastic lamina, particularly in right-sided tumors, may limit the use of ELI as a prognostic marker in CRC.

The phenotypic expression of inflammatory bowel disease in patients with primary sclerosing cholangitis differs in the distribution of colitis

BACKGROUND

Inflammatory bowel disease (IBD) associated with primary sclerosing cholangitis (PSC) is reported to be mild and prone to right-side predominance with rectal sparing. However, no dedicated studies evaluating patterns of presentation of liver disease with respect to IBD are available.

METHODS

We performed a detailed histological examination of the colonic biopsies in the context of PSC, identifying 97 patients [89 with ulcerative colitis and ten with Crohn's disease (CD)] stratified into two groups, based on their initial disease presentation: hepatic/biliary (group 1-PSC-IBD; n=56) versus colonic (group 2-IBD-PSC; n=41).

RESULTS

Inflammatory bowel disease that preceded PSC had a tendency to have a "pan-colitis" distribution; this group included all patients with CD. Inflammatory bowel disease diagnosis that followed PSC presentation was more likely to be right-sided, sparing the descending, sigmoid and rectal regions (p=0.002). In both groups, colitis was mild with focal deep plasmacytosis and occasional mild cryptitis. Active cryptitis with crypt abscesses, surface erosion and ulceration were not identified in any of the patients.

CONCLUSION

Colitis associated with PSC shows mild disease activity and the colitis pattern is associated with disease presentation, i.e. colitis preceding PSC (IBD-PSC cohort) typically have a pancolitic distribution, while colitis following PSC (PSC-IBD cohort) demonstrates right-sided predominance. Awareness by pathologists and clinicians of these patterns of inflammatory bowel disease is important and of use in directing appropriate investigations for patients.

Primary esophageal and gastro-esophageal junction cancer xenograft models: clinicopathological features and engraftment

There are very few xenograft models available for the study of esophageal (E) and gastro-esophageal junction (GEJ) cancer. Using a NOD/SCID model, we implanted 90 primary E and GEJ tumors resected from patients and six endoscopic biopsy specimens. Of 69 resected tumors with histologically confirmed viable adenocarcinoma or squamous cell carcinoma, 22 (32%) was engrafted. One of 11 tumors, considered to have had a complete pathological response to neo-adjuvant chemo-radiation, also engrafted. Of the 23 patients whose tumors were engrafted, 65% were male; 30% were early stage while 70% were late stage; 22% received neo-adjuvant chemo-radiation; 61% were GEJ cancers. Engraftment occurred in 18/54 (33%) adenocarcinomas and 5/16 (31%) squamous cell carcinomas. Small endoscopic biopsy tissue had a 50% (3/6) engraftment rate. Of the factors analyzed, pretreatment with chemo-radiation and well/moderate differentiation showed significantly lower correlation with engraftment (P<0.05). In the subset of patients who did not receive neo-adjuvant chemo-radiation, 18/41 (44%) engrafted compared with those with pretreatment where 5/29 (17%, P=0.02) engrafted. Primary xenograft lines may be continued through 4-12 passages. Xenografts maintained similar histology and morphological characteristics with only minor variations even after multiple passaging in most instances.

Primary angiosarcoma of the esophagus

Primary angiosarcoma of the esophagus is an extremely rare soft-tissue tumor with no previously documented cases in the MEDLINE and EMBASE databases as of April 2012. We report a case of primary esophageal angiosarcoma in an otherwise healthy 77-year-old woman presenting with odynophagia and epigastric discomfort.

Barrett's esophagus: prevalence-incidence and etiology-origins

Although the prevalence of Barrett's esophagus (BE) is rising no data exist for racial minorities on prevalence in the general population. Minorities have a lower prevalence than Caucasians, and yet age, smoking, abdominal obesity, and Helicobacter pylori are all risk factors. Metabolic changes induced by adipocytokines and the apparently strong association between obesity, central adiposity, and BE may lead to reconsideration of some aspects of the natural history of BE. There is lack of experimental evidence on acid sensitivity and BE, which is hyposensitive compared to esophageal reflux disease. Reactive nitrogen and oxygen species lead to impaired expression of tumor suppressor genes, which can lead to cancer development; thus, antioxidants may be protective. Gastroesophageal reflux disease may be considered an immune-mediated disease starting at the submucosal layer; the cytokine profile of the mucosal immune response may explain the different outcome of gastroesophageal reflux.

Canadian Association of Pathologists-Association canadienne des pathologistes National Standards Committee/Immunohistochemistry: best practice recommendations for standardization of immunohistochemistry tests

Immunohistochemical and immunocytochemical assays are highly complex diagnostic analyses used to aid in the accurate identification and biologic characterization of tissue types in neoplastic and nonneoplastic diseases. Immunohistochemical tests are applied mainly to the diagnosis of neoplasms. Some immunohistochemical tests provide information of important prognostic and predictive value in selected human neoplasms and, as such, are often critical for the appropriate and effective treatment of patients. This document provides recommendations and opinions of the Canadian Association of Pathologists-Association canadienne des pathologistes National Standards Committee/Immunohistochemistry relevant to clinical immunohistochemical terminology, classification of immunohistochemical tests based on risk assessment, and quality control and quality assurance and summarizes matters to be considered for appropriate immunohistochemical/immunocytochemical test development, performance, and interpretation in diagnostic pathology and laboratory medicine.

Urea breath test in children: the United States prospective, multicenter study

BACKGROUND

The urea breath test (UBT) is generally considered the gold standard for the diagnosis of Helicobacter pylori infections in adults.

GOALS

To investigate the utility and accuracy of urea breath testing in children from the United States.

METHODS

Children scheduled to undergo upper gastrointestinal endoscopy for various clinical symptoms underwent a 13C-UBT using the US standard protocol for adults. Results were compared with rapid urease testing (RUT), culture, and histology. H. pylori positivity was defined according to the FDA, Division of Anti-Infective Drug Products criteria, i.e. positive culture and/or positive RUT and histology. H. pylori negativity was defined as all tests negative. Results were evaluated by delta over baseline (DOB) and urea hydrolysis rate (UHR).

RESULTS

A total of 176 children from five centers were evaluated; 48 were infected. Compared to the defined standard, the results with the UBT based on delta over baseline (DOB) cut-off value (positive: > or = 2.4 per thousand) showed that the sensitivity and specificity of the UBT were 97.9% and 96.1%, respectively. Based on the UHR cut-off value (positive: > or = 10.0 microg/min), the sensitivity and specificity were 95.8% and 99.2%. In young children (2- to 5-year olds), sensitivity and specificity of UHR method were higher than the DOB method (100% and 100% vs 100% and 82.4%, respectively).

CONCLUSION

The US standard (13)C-UBT proved to be both simple and accurate for the diagnosis of H. pylori infections in children. The UHR method to calculate of (13)C-UBT result provided excellent results for children of all ages.

Adherence, internalization, and persistence of Helicobacter pylori in hepatocytes

Although Helicobacter pylori have been identified in the liver, the role of Helicobacter sp. in human liver diseases remains unclear. This study explored whether H. pylori were internalized and could persist in hepatocytes. The majority of an inoculum of H. pylori (1 x 10(7) colony forming units) adhered to hepatocytes. Using the gentamicin invasion assay we found that approximately 2% were internalized and persisted following passage for more than 2 months. Electron microscopy confirmed the presence of intracellular Helicobacter. The number of adherent or internalized H. pylori was significantly greater with hepatocytes than with gastric epithelial cells (P < 0.05) and was also dependent on cag pathogenicity island (PAI), VacA, OipA, or BabA status. Transmission electron microscopy was used to confirm adherence and invasion of H. pylori into hepatocytes. Internalization of H. pylori was inhibited by antibodies to beta1-integrin receptors, genistein, and cytochalasin D (P < 0.05) consistent with beta1-integrin acting as a surface receptor with additional requirements for tyrosine kinase phosphorylation and actin polymerization. In summary, H. pylori both adhered to and invaded into hepatocytes in vitro, depending on the virulent factors, and persisted within hepatocytes during subcultures. beta1-integrin is likely a receptor involved in internalization of H. pylori into hepatocytes.

Comparative genomic hybridization of ectopic pregnancies that fail methotrexate therapy

Ectopic pregnancies that fail methotrexate therapy are predominantly euploid by comparative genomic hybridization (CGH). This feasibility study also confirms that formalin-fixed paraffin-embedded gestational tissue can successfully undergo CGH.

Disinfection of endoscopes from Helicobacter pylori-positive subjects: evaluation of the effectiveness of the Chinese Calijing disinfection kit

BACKGROUND

The aim of this study was to evaluate the effectiveness of the Calijing disinfection kit (an endoscope disinfection method used in Chinese hospitals) in eradicating Helicobacter pylori and assess whether use of the kit in 1994 during endoscopies in the Shandong Intervention Trial (SIT), Shandong, China, could have resulted in iatrogenic transmission of H pylori .

METHODS

Bacterial culture studies at the Veterans Affairs Medical Center, Houston, Texas, using endoscopes and forceps from 49 H pylori -positive patients were performed on contaminated endoscopes before and after disinfection with the Calijing kit.

RESULTS

At least 1 endoscope culture site was H pylori positive in 39 of 49 (79.6%) specimens predisinfection, whereas H pylori was not isolated from any endoscopic culture site postdisinfection. Non- H pylori bacteria and fungi were recovered from 22.6% of the postdisinfection cultures.

CONCLUSION

Although no viable H pylori were recovered following the disinfection procedures, levels of H pylori below the detection threshold of the bacteriologic assay may have contributed to an increase in H pylori seroprevalence noted in the SIT. In addition, the kit was unable to provide disinfection against non- H pylori organisms, suggesting the need to adhere to internationally accepted disinfection procedures for endoscope reprocessing.

Bismuth-based quadruple therapy using a single capsule of bismuth biskalcitrate, metronidazole, and tetracycline given with omeprazole versus omeprazole, amoxicillin, and clarithromycin for eradication of Helicobacter pylori in duodenal ulcer patients: a prospective, randomized, multicenter, North American trial

OBJECTIVES

This multicenter, randomized, active-controlled trial assessed efficacy of bismuth-based quadruple therapy with omeprazole, bismuth biskalcitrate, metronidazole, and tetracycline (OBMT) using a single-triple capsule of BMT compared with triple therapy with omeprazole, amoxicillin, and clarithromycin (OAC) in treatment of patients with Helicobacter pylori infection and duodenal ulcers.

METHODS

Patients with active duodenal ulcer or diagnosed within the past 5 yr and with infection documented by (13)C-urea breath test plus histology or culture were randomly assigned to 10-day course of OBMT using a single-triple capsule containing bismuth biskalcitrate 140 mg, metronidazole 125 mg, and tetracycline 125 mg given as three capsules q.i.d. with omeprazole 20 mg b.i.d., or a 10-day course of OAC, omeprazole 20 mg plus amoxicillin 1 g plus clarithromycin 500 mg, all b.i.d. Eradication was confirmed by two negative urea breath tests at >1 month and >2 months after therapy.

RESULTS

One hundred thirty-eight patients received OBMT and 137 OAC. Modified intent-to-treat eradication rates were 87.7% for OBMT and 83.2% for OAC (95% CI = -3.9%-12.8%; p = 0.29). OBMT eradicated 91.7% metronidazole-sensitive and 80.4% metronidazole-resistant strains (p = 0.06). OAC eradicated 92.1% clarithromycin sensitive and 21.4% clarithromycin-resistant strains (p < 0.001). Adverse events occurred in 58.5% of OBMT patients and 59.0% of OAC patients.

CONCLUSIONS

OBMT regimen using the single-triple capsule is as efficacious and well-tolerated as the widely used OAC regimen for H. pylori eradication. This OBMT therapy largely overcomes H. pylori metronidazole resistance, present in 40% of patients in this study.

Bismuth-based quadruple therapy using a single capsule of bismuth biskalcitrate, metronidazole, and tetracycline given with omeprazole versus omeprazole, amoxicillin, and clarithromycin for eradication of Helicobacter pylori in duodenal ulcer patients: a prospective, randomized, multicenter, North American trial

OBJECTIVES

This multicenter, randomized, active-controlled trial assessed efficacy of bismuth-based quadruple therapy with omeprazole, bismuth biskalcitrate, metronidazole, and tetracycline (OBMT) using a single-triple capsule of BMT compared with triple therapy with omeprazole, amoxicillin, and clarithromycin (OAC) in treatment of patients with Helicobacter pylori infection and duodenal ulcers.

METHODS

Patients with active duodenal ulcer or diagnosed within the past 5 yr and with infection documented by (13)C-urea breath test plus histology or culture were randomly assigned to 10-day course of OBMT using a single-triple capsule containing bismuth biskalcitrate 140 mg, metronidazole 125 mg, and tetracycline 125 mg given as three capsules q.i.d. with omeprazole 20 mg b.i.d., or a 10-day course of OAC, omeprazole 20 mg plus amoxicillin 1 g plus clarithromycin 500 mg, all b.i.d. Eradication was confirmed by two negative urea breath tests at >1 month and >2 months after therapy.

RESULTS

One hundred thirty-eight patients received OBMT and 137 OAC. Modified intent-to-treat eradication rates were 87.7% for OBMT and 83.2% for OAC (95% CI = -3.9%-12.8%; p = 0.29). OBMT eradicated 91.7% metronidazole-sensitive and 80.4% metronidazole-resistant strains (p = 0.06). OAC eradicated 92.1% clarithromycin sensitive and 21.4% clarithromycin-resistant strains (p < 0.001). Adverse events occurred in 58.5% of OBMT patients and 59.0% of OAC patients.

CONCLUSIONS

OBMT regimen using the single-triple capsule is as efficacious and well-tolerated as the widely used OAC regimen for H. pylori eradication. This OBMT therapy largely overcomes H. pylori metronidazole resistance, present in 40% of patients in this study.

Assessment of liver histology in chronic alcoholics with and without hepatitis C virus infection

Patients with alcoholic liver disease have a high prevalence of hepatitis C virus (HCV) infection. The histological appearances of the liver in patients with alcoholic liver disease and HCV infection are well described. However, liver histology in individuals with dual pathology, both chronic alcohol abuse and HCV infection, is less well understood. The purpose of the present study was to examine this issue and to determine if there is any correlation between specific histological features and the serum biochemical abnormalities seen in these patients. Eighty-six chronic alcoholics, 65 with HCV infection and 21 uninfected subjects, were included in the study. All patients had history of heavy alcohol abuse (consuming 80 g or more of ethanol a day for at least 10 years). The following data were collected on each patient: demographic information (age, gender, race), the amount and duration of alcohol intake, biochemical results, and liver biopsy abnormalities including the histological activity index (HAI) score. HCV-infected alcoholics were younger (P = 0.05) and were more often African American than Caucasian (P < 0.01). Alcohol consumption was significantly greater in uninfected alcoholics compared to those with HCV infection (P < 0.05). Liver histology in subjects with HCV infection showed higher HAI scores for intralobular necrosis (P = 0.008) and periportal inflammation (P = 0.004). Features of "chronic hepatitis" and focal lymphoid aggregates were more frequent in HCV-infected alcoholics (P = 0.001 for each). By contrast, cirrhosis was present in a higher proportion of uninfected alcoholics compared to those with HCV infection (P = 0.05). Histological findings of hepatic fibrosis and total HAI score showed a significant correlation with serum albumin and platelet count in HCV-infected alcoholics. Chronic alcoholics with HCV infection have specific histological appearances that can usually help distinguish these patients from uninfected alcoholics. Correlation analysis indicates that of the various laboratory tests, serum albumin and platelet counts are the best predictors of the severity of liver damage at histology. In chronic alcoholics, the development of cirrhosis is related more to the amount of alcohol consumed than to the presence of HCV infection.

Isolation of Helicobacter pylori from sheep-implications for transmission to humans

OBJECTIVES

When and how Helicobacter pylori (H. pylori) originally entered the human population as well as how the infection is transmitted in different communities is unknown. We previously showed that Sardinian shepherds had almost a 100% prevalence of H. pylori and that the prevalence was higher than that of their same-household siblings.

AIM

To examine whether H. pylori infection might be transmitted from sheep.

METHODS

Milk and gastric tissue were cultured and analyzed by PCR amplification using three sets of primers Helicobacter genus-specific 16S rRNA and two sets of primers specific for H. pylori vacA gene.

RESULTS

Helicobacter DNA was demonstrated in 60% (38/63) of milk samples and in 30% (6/20) of sheep tissue samples. H. pylori vacA gene was amplified in five of 38 milk samples, and in two of six sheep tissue samples respectively. H. pylori were cultured from sheep milk and tissue samples and confirmed as H. pylori on the basis of colony morphology, positive biochemical reactions, and negative Gram stain. Sequence analysis of 16S rRNA PCR products from these isolates demonstrated 99% identity with H. pylori.

CONCLUSIONS

Together, the presence of H. pylori in sheep stomach in the absence of associated gastritis and recovery of H. pylori from sheep milk and gastric tissue suggest that sheep may be a natural host for H. pylori.

Intestinal metaplasia with adherent Helicobacter pylori: a hybrid epithelium with both gastric and intestinal features

Helicobacter pylori seem to avoid areas of intestinal metaplasia in the gastric mucosa, but attachment of these bacteria to epithelium with the appearance of incomplete intestinal metaplasia has been documented. To characterize the nature of the epithelium to which H pylori was attached, we carried out an immunohistochemical study using monoclonal antibodies against gastric surface mucous cell mucins (M1), blood group-related carbohydrates antigens (Le(a), sialyl Le(a), Le(b), type 1H, and type 2H) and sialyl Tn antigen. The results of this study suggest that these areas of H pylori attachment represent a hybrid epithelium whose cells share characteristics of both gastric surface mucous cells and intestinal metaplastic cells. Whether all areas of incomplete intestinal metaplasia represent an intermediate stage between the normal gastric epithelium and the fully developed complete type of metaplasia remains to be determined.