High proportion of granzyme B-positive (activated) intraepithelial and lamina propria lymphocytes in lymphocytic gastritis

Rare Gastric Lesions Associated with Helicobacter pylori Infection: A Histopathological Review

Helicobacter pylori infection is associated with chronic gastritis, peptic ulcer disease, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. However, some rare gastric lesions exhibiting distinctive histological features may also be associated with H. pylori infection, including lymphocytic gastritis, granulomatous gastritis, Russell body gastritis, or crystal-storing histiocytosis. Although diverse factors can contribute to their development, there is convincing evidence that H. pylori infection may play a pathogenic role. These findings are mainly based on studies in patients with these lesions who exhibited clinical and histological improvements after H. pylori eradication therapy. Thus, H. pylori eradication therapy might be indicated in patients with no other underlying disease, particularly in countries with a high prevalence of H. pylori infection. This review describes the characteristic histological features of these rare lesions and evaluates the evidence regarding a causative role for H. pylori infection in their pathogenesis.

Propionibacterium acnes overabundance and natural killer group 2 member D system activation in corpus-dominant lymphocytic gastritis

Corpus‐dominant lymphocytic gastritis (LyG) is characterized by CD8⁺ T‐cell infiltration of the stomach epithelium by a so far uncharacterized mechanism. Although Helicobacter pylori is typically undetectable in LyG, patients respond to H. pylori antibiotic eradication therapy, suggesting a non‐H. pylori microbial trigger for the disease. Comparative microbiota analysis of specimens from LyG, H. pylori gastritis and healthy controls precluded involvement of H. pylori in LyG but identified Propionibacterium acnes as a possible disease trigger. In addition, the natural killer group 2 member D (NKG2D) system and the proinflammatory cytokine interleukin (IL)‐15 are significantly upregulated in the gastric mucosa of LyG patients, and gastric epithelial cells respond to microbe‐derived stimuli, including live P. acnes and the microbial products short‐chain fatty acids, with induction of NKG2D ligands. In contrast, H. pylori infection does not activate or even repress NKG2D ligands. Together, our findings identify P. acnes as a possible causative agent for LyG, which is dependent on the NKG2D system and IL‐15 activation. © 2016 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.

Immunology and vaccines and nanovaccines for Helicobacter pylori infection

Helicobacter pylori infection is very common worldwide and is an important cause of gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma, and gastric adenocarcinoma. Since the eradication requires treatment with multidrug regimens, prevention of primary infection by a suitable vaccine is attractive. Developing vaccines on the spot when and where an infection is breaking out might be possible, thanks to engineered nanoparticles. In this review, the nature of the host immune response to H. pylori infection is considered. We explain recent candidate vaccines and prophylactic or therapeutic immunization strategies for use against H. pylori. We also describe identification of different types of immune responses that may be related to protection against H. pylori infection. Thus, it seems that there is still a strong need to clarify the main protective immune response against H. pylori.

Lymphocytic gastritis is not associated with active Helicobacter pylori infection

BACKGROUND

Lymphocytic gastritis (LG), characterized by marked intra-epithelial lymphocytosis in the gastric mucosa, has been frequently associated with both celiac disease (CD) and H. pylori gastritis. The aim of this study was to review and correlate the morphology of LG with the presence of CD and H. pylori.

MATERIALS AND METHODS

Gastric biopsies diagnosed with LG from 1/1/2006 to 8/1/2013 at our institution and corresponding small bowel biopsies, when available, were reviewed for verification of the diagnosis and to assess for the presence of H. pylori and CD. Immunohistochemical (IHC) staining for H. pylori was performed on all gastric biopsies. Demographic, clinical, and laboratory data were obtained from the medical record.

RESULTS

Fifty-four of the 56 cases that met inclusion criteria demonstrated significant intra-epithelial lymphocytosis as the predominant histologic abnormality; however, none were associated with H. pylori infection by IHC staining. Two cases that also showed a prominent intra-epithelial and lamina propria neutrophilic infiltrate were both positive for H. pylori and were excluded from further study. Of the 36 small bowel biopsies available, 19 (53%) showed changes in CD.

CONCLUSIONS

LG is not a distinct clinicopathologic entity, but a morphologic pattern of gastric injury that can be secondary to a variety of underlying etiologies. When restricted to cases with lymphocytosis alone, LG is strongly associated with CD and not with active H. pylori infection. However, cases that also show significant neutrophilic infiltrate should be regarded as "active chronic gastritis" and are often associated with H. pylori infection. A morphologic diagnosis of LG should prompt clinical and serologic workup to exclude underlying CD.

Helicobacter pylori Associated Lymphocytic Gastritis in a Child

Lymphocytic gastritis (LG) is a rare subtype of chronic gastritis. It is defined as dense proliferation of intraepithelial lymphocytes (IELs) more than 25 lymphocytes per 100 epithelial cells. The known major causes of LG are celiac disease and Helicobacter pylori infection. H. pylori associated LG (HpLG) has more enhanced cytotoxic and apoptotic tendencies than chronic H. pylori gastritis. A 12-year-old girl with postprandial epigastric pain was diagnosed HpLG on endoscopic biopsy. After the 1st eradication therapy, H. pylori bacilli were still found, and urea breathing test was positive. Although the endoscopic finding was partially improved, clinical symptoms and histologic finding were persisted. We could achieve the improvement of clinical symptoms and disappearance of IELs after the 2nd eradication. The discordant of histopathologic and endoscopic improvement occurred after the 1st eradication therapy of HpLG. Therefore the clinical and histopathologic evaluation should be considered as well as endoscopic findings.

High proportion of granzyme B+ intraepithelial lymphocytes contributes to epithelial apoptosis in Helicobacter pylori-associated lymphocytic gastritis

BACKGROUND

Helicobacter pylori infection has been linked to the development of lymphocytic gastritis (LG) characterized by ≥25 intraepithelial lymphocytes (IELs) per 100 epithelial cells. We hypothesize that the changes in the subpopulation and/or cytotoxicity of IELs leading to epithelial cell apoptosis may be involved in the pathogenesis of H. pylori-associated LG.

MATERIALS AND METHODS

We examined IEL subpopulations and the expression of cytotoxic molecules by IELs in biopsy specimens from 36 patients with H. pylori-associated LG by immunostainings for CD3, CD4, CD8, T-cell-restricted intracellular antigen-1 (TIA-1), and granzyme B (GrB) and compared the results with those obtained from 49 patients with H. pylori-associated gastritis (HPG). To investigate whether the IEL-mediated cytotoxicity is related to the increase of epithelial apoptosis, we performed a terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay using ApopTag detection kit.

RESULTS

Between LG and HPG groups, significant differences in the number of CD3+, CD4+, CD8+, TIA-1+ or GrB+ IELs, and ApopTag indices were found. Among the CD3+ IELs, the proportion of CD8+ IELs or TIA-1+ IELs did not differ between two groups. The LG group showed a selective increase in GrB-positive, phenotypically activated IELs, which was paralleled by an increase in ApopTag indices. In contrast, the HPG group showed more heterogeneous IEL subpopulations with more CD4+ IELs and less GrB+ IELs compared with the LG group, and we did not find any significant variable contributing to the epithelial apoptosis in the HPG group.

CONCLUSIONS

This study shows that in addition to the numerical increase in the IELs, there are significant changes in the subpopulations and cytotoxicity of IELs between HPG and H. pylori-associated LG. In particular, enhanced GrB-associated cytotoxicity of the IELs in H. pylori-associated LG contributes to an increase in epithelial apoptosis.

Clinicopathological characteristics of primary gastric T-cell lymphoma

AIMS

To investigate the clinicopathological characteristics of 20 primary gastric T-cell lymphoma (GTCL) cases without human T-lymphotropic virus type I infection in Japan, a non-endemic area for coeliac disease.

METHODS AND RESULTS

Fifteen cases had no history of persistent diarrhoea or severe hypoproteinaemia. Histologically, 13 cases (65%) consisted of large cell lymphoma and seven (35%) were of medium-sized cells. Intraepithelial lymphoma cell invasion was found in three cases (15%). Two of 10 surgical cases (20%) showed intramucosal tumour cell spreading with enteropathy-like features. Helicobacter pylori CagA gene was detected in three of 10 cases (30%). The lymphoma cells of all 20 cases were positive for CD3 and/or TCRbetaF1 and negative for CD56. CD4- and CD8- lymphoma was found in 11 cases (55%), CD4+ lymphoma in seven (35%) and CD8+ lymphoma in two (10%). CD30+, CD5+ and CD25+ lymphomas were detected in nine (45%), 10 (50%) and 11 (55%) cases, respectively. Five-year survival of the 16 available cases was 54%. Early clinical stage and medium-sized cell lymphoma were significantly (P < 0.05) better prognostic factors.

CONCLUSIONS

Patients with GTCL exhibit distinct clinicopathological findings and prognoses from those with enteropathy-associated T-cell lymphomas. GTCL may be mainly derived from lamina propria and parafollicular T cells.

Pathology of non-Helicobacter pylori gastritis: extending the histopathologic horizons

The development of modern endoscopic techniques, easier and greater access to healthcare, and interest in Helicobacter pylori infection and its implications have all led to a significant increase in upper endoscopies. In turn, gastroenterologists and pathologists have been recognizing an ever-increasing number of patterns of mucosal injury. Consequently, there is now an interest in a wider aspect of non-neoplastic gastric pathology, namely, non-HP (H. pylori) gastritis. In this review, we present major clinico-pathological entities, based on either the salient morphological features or the underlying etiologies.

Intracellular versus extracellular granzyme B in immunity and disease: challenging the dogma

The cytotoxic granzyme B (GrB)/perforin pathway has been traditionally viewed as a primary mechanism that is used by cytotoxic lymphocytes to eliminate allogeneic, virally infected and/or transformed cells. Although originally proposed to have intracellular and extracellular functions, upon the discovery that perforin, in combination with GrB, could induce apoptosis, other potential functions for this protease were, for the most part, disregarded. As there are 5 granzymes in humans and 11 granzymes in mice, many studies used perforin knockout mice as an initial screen to evaluate the role of granzymes in disease. However, in recent years, emerging clinical and biochemical evidence has shown that the latter approach may have overlooked a critical perforin-independent, pathogenic role for these proteases in disease. This review focuses on GrB, the most characterized of the granzyme family, in disease. Long known to be a pro-apoptotic protease expressed by cytotoxic lymphocytes and natural killer cells, it is now accepted that GrB can be expressed in other cell types of immune and nonimmune origin. To the latter, an emerging immune-independent role for GrB has been forwarded due to recent discoveries that GrB may be expressed in nonimmune cells such as smooth muscle cells, keratinocytes, and chondrocytes in certain disease states. Given that GrB retains its activity in the blood, can cleave extracellular matrix, and its levels are often elevated in chronic inflammatory diseases, this protease may be an important contributor to certain pathologies. The implications of sustained elevations of intracellular and extracellular GrB in chronic vascular, dermatological, and neurological diseases, among others, are developing. This review examines, for the first time, the multiple roles of GrB in disease pathogenesis.

The immunohistochemistry profile of lymphocytic gastritis in celiac disease and helicobacter pylori infection: interplay between infection and inflammation

Lymphocytic gastritis (LG) is associated with helicobacter pylori (Hp) and celiac disease (CD). We aimed to clarify the relationship between Hp infection and CD by defining a unique histopathology profile of LG in these two diseases. Forty patients who underwent upper endoscopy were divided into four groups: eight controls, ten active CD patients without Hp, twelve CD negative with Hp, and ten active CD with Hp infection. Antral samples were assessed by immunohistochemical staining for CD20, CD3, CD4, CD8, CD57, CNA42, and Ki67 for lymphoid aggregates, intraepithelial lymphocytes (IELs) number, density of lamina propria (LP) lymphocytes, and inflammatory glandular involvement. Only IELs positive for CD3 and CD8 were increased significantly in CD patients with or without Hp infection. Hp did not contribute to the number of CD8 IELs. In complicated cases with Hp and suspicious for CD, the number of CD8+ IELs hints toward a CD rather than Hp infection.

Helicobacter pylori vaccine: from past to future

Helicobacter pylori infection is highly prevalent worldwide and is an important cause of gastritis, peptic ulcer disease, gastric mucosa-associated lymphoid tissue lymphoma (MALToma), and gastric adenocarcinoma. Infection is usually acquired during childhood and tends to persist unless treated. Because eradication requires treatment with multidrug regimens, prevention of initial infection by a suitable vaccine is attractive. Although immunization with H pylori protein subunits has been encouraging in animals, similar vaccine trials in humans have shown adjuvant-related adverse effects and only moderate effectiveness. Newer immunization approaches (use of DNA, live vectors, bacterial ghosts, and microspheres) are being developed. Several questions about when and whom to vaccinate will need to be appropriately answered, and a cost-effective vaccine production and delivery strategy will have to be useful for developing countries. For this review, we searched MEDLINE using the Medical Subject Heading (MeSH) terms Helicobacter pylori and vaccines for articles in English from 1990 to 2007.

The pathology of malabsorption: current concepts

Intestinal malabsorption results from a wide variety of causes, which can most easily be organized into three groups. Maldigestion arises from problems with mixing or with digestive mediators, and includes post-gastrectomy patients and those with deficiencies of pancreatic or intestinal enzymes, or of bile salts. Mucosal and mural causes of malabsorption are abundant, and include gluten-sensitive enteropathy, tropical sprue, autoimmune enteropathy, and HIV/AIDS-related enteropathy, as well as mural conditions such as systemic sclerosis. Finally, microbial causes of malabsorption include bacterial overgrowth, Whipple's disease, and numerous infections or infestations that are most frequently seen in immunocompromised patients. An overview of the most common and interesting entities in each of these categories follows, along with a discussion of current concepts. Mucosal conditions and microbial causes of malabsorption are given special attention.

Pathology of non-infective gastritis

The discovery of Helicobacter pylori and its intimate role in the development of the most common form of chronic gastritis has elicited a much-needed interest in non-neoplastic gastric pathology. This has been paralleled by an increase in upper endoscopic examinations, which allow recognition of novel patterns and distribution of mucosal injury. Numerous attempts at classification have been made, most based on the acuteness or chronicity of gastric mucosal injury. In this review, we will not offer a new classification but present a detailed description of the major clinicopathological entities, based either on the salient morphological features or the underlying aetiologies, i.e. iatrogenic, autoimmune, vascular or idiopathic.

Healing of lymphocytic gastritis after Helicobacter pylori eradication therapy--a randomized, double-blind, placebo-controlled multicentre trial

BACKGROUND

An association between Helicobacter pylori infection and lymphocytic gastritis has been postulated.

AIM

To assess the long-term effect of H. pylori eradication therapy on lymphocytic gastritis in a double-blind, placebo-controlled, multicentre trial.

METHODS

Patients with lymphocytic gastritis were randomized to receive either 1-week triple therapy for eradication of H. pylori or omeprazole plus placebo. Endoscopy and histology was performed at baseline and after 3 and 12 months. Patients of the omeprazole/placebo group with persistent lymphocytic gastritis after 12 months received crossover open-label triple therapy.

RESULTS

Fifty-one patients were randomized. Intention-to-treat analysis revealed a trend to a higher healing rate of lymphocytic gastritis 3 months after triple therapy compared with omeprazole/placebo (83.3% vs. 57.7%, 95% CI for RR: 0.8-2.8, P = 0.06). After 12 months, the healing rate of lymphocytic gastritis was significantly higher after triple therapy compared with omeprazole/placebo (intention-to-treat 95.8% vs. 53.8%, 95% CI for RR: 1.1-3.5, P = 0.01). All patients (n = 5) who received crossover triple therapy, showed healing of lymphocytic gastritis after further 12 months.

CONCLUSION

Our study demonstrates that 1-week triple therapy aiming at eradication of H. pylori leads to a complete and long-lasting resolution of lymphocytic gastritis in the majority of patients.

Upregulation of cathepsin W-expressing T cells is specific for autoimmune atrophic gastritis compared to other types of chronic gastritis

AIM: To investigate a pathophysiological role of cathepsin W (CatW), a putative thiol-dependent cysteine protease, which is specifically expressed in cytotoxic lymphocytes, in different types of chronic inflammation of the gastric mucosa.

METHODS: Gastric and duodenal biopsies of patients with Helicobacter pylori (H pylori)-associated active gastritis (Hp, n = 19), chemically induced reactive gastritis (CG, n = 17), autoimmune atrophic gastritis (AIG, n = 20), lymphocytic corpus gastritis (LG, n = 29), celiac disease (CD, n = 10), and corresponding controls (n = 24) were analyzed by immunohistochemistry for the expression of CatW and CD45. Furthermore, immunohistochemical double staining with anti-CD3 and anti-cathepsin was performed for the samples of AIG.

RESULTS: Median values of CatW-expressing cells among CD45-positive immune cells were between 2% and 6% for normal gastric mucosa, CG, and LG, whereas the corresponding value was significantly increased for AIG (24.7%, P<0.001) and significantly decreased for HP (0.7%, P<0.05). Double staining with anti-CD3 and anti-CatW antibodies revealed that >90% of CatW-expressing cells in gastric mucosa of AIG were T cells. Duodenal mucosa had significantly more CatW/CD45-positive cells than normal gastric mucosa (median: 17.8% vs 2%, P<0.01). The corresponding proportion of CatW/CD45-positive cells was decreased in CD compared to duodenal mucosa (median: 2.1% vs 17.8%, P<0.05).

CONCLUSION: The opposite findings regarding the presence of CatW-positive cells in AIG (increase) and CD (decrease) reflects the different cellular composition of immune cells involved in the pathogenesis of these diseases.

Duodenal intraepithelial lymphocytosis with normal villous architecture: common occurrence in H. pylori gastritis

We have observed expansions of intraepithelial lymphocytes in duodenal biopsies from patients with Helicobacter pylori gastritis. This study was undertaken to prospectively evaluate, unselected, paired gastric and duodenal biopsies from 50 patients with H. pylori gastritis and a comparison group of 30 patients with other types of gastritis (10 autoimmune and 20 reactive) to: (1) quantify duodenal intraepithelial lymphocytes, determine their distribution patterns, epithelial location, and phenotype, and (2) correlate the intraepithelial lymphocyte elevations with various features of gastric and duodenal pathology. Intraepithelial lymphocytes were analyzed with antibodies including CD3, CD8, and TIA-1. A stain for H. pylori was performed on all gastric and duodenal biopsies. Duodenal intraepithelial lymphocytes from patients with H. pylori gastritis (using CD3) ranged from 3 to 42 lymphocytes/100 epithelial cells (mean 18.5) compared to 3 to 18 lymphocytes/100 epithelial cells (mean 6.6) in the comparison group. Intraepithelial lymphocyte elevations were seen in 44% of the duodenal biopsies from patients with H. pylori gastritis (using CD3). Significant differences in the intraepithelial lymphocyte counts between patients with H. pylori gastritis and the comparison group were seen for all three T-cell antigens (P<0.001 for CD3 and CD8 and P<0.002 for TIA-1). Duodenal intraepithelial lymphocytes in the H. pylori+ cases had a latent cytotoxic phenotype, H. pylori was not visualized in any of the duodenal biopsies from patients with H. pylori gastritis, and no patient had clinical evidence of celiac disease. Our study highlights frequent duodenal intraepithelial lymphocytosis in individuals with H. pylori gastritis and the lymphocyte distribution patterns (and numbers) overlapped with those described for celiac disease patients. H. pylori gastritis must be considered as a possible explanation for duodenal intraepithelial lymphocytosis with normal villous architecture, especially when lymphocytosis is patchy, intraepithelial lymphocytes display a 'latent' cytotoxic phenotype, and the clinical findings and serologic profile does not fit celiac disease.

Immune response in Helicobacter pylori-induced low-grade gastric-mucosa-associated lymphoid tissue (MALT) lymphoma

We have reported previously that heat-shock protein 60 kDa (hsp60) of Helicobacter pylori is an important antigen in the pathogenesis of gastric mucosa-associated lymphoid tissue (MALT) lymphoma. In order to investigate associations with host immune reactions and hsp60 antigen, CD40 ligand (CD40L) expression and cytokine production were analysed following stimulation with hsp60. To provide a clear antigen-driven immune response, peripheral blood mononuclear cells (PBMC) from patients with low-grade MALT lymphoma and gastritis and those from healthy volunteers were stimulated with recombinant H. pylori hsp60 and H. pylori cell lysate in the presence of cytokines (IL4 and granulocyte-macrophage colony-stimulating factor). mRNA expression was also analysed by a cDNA microarray containing 1100 genes. Expression of CD40L on PBMCs of patients with MALT lymphoma was increased by cytokines or by combination with stimulation with hsp60 antigens. The production of IL4 in PBMC cultures was increased in patients with MALT lymphoma; however, production of IFN-gamma was at low levels. DNA microarray analysis indicated increased levels of HLA-DR and integrin mRNAs. In cases of low-grade MALT lymphoma, adaptive immune responses against hsp60 may be enhanced by host factors, such as antigen presentation and T-cell activation, resulting in B-cell proliferation, which can be demonstrated during chronic H. pylori infection.

Epithelial cell proliferation and glandular atrophy in lymphocytic gastritis: Effect of H pylori treatment

AIM: Lymphocytic gastritis is commonly associated with Helicobacter pylori infection. The presence of glandular atrophy and foveolar hyperplasia in lymphocytic gastritis suggests abnormalities in cell proliferation and differentiation, forming a potential link with the suspected association with gastric cancer. Our aim was to compare epithelial proliferation and morphology in H pylori associated lymphocytic gastritis and H pylori gastritis without features of lymphocytic gastritis, and to evaluate the effect of H pylori treatment.

METHODS: We studied 14 lymphocytic gastritis patients with H pylori infection. For controls, we selected 14 matched dyspeptic patients participating in another treatment trial whose H pylori infection had successfully been eradicated. Both groups were treated with a triple therapy and followed up with biopsies for 6-18 months (patients) or 3 months (controls). Blinded evaluation for histopathological features was carried out. To determine the cell proliferation index, the sections were labeled with Ki-67 antibody.

RESULTS: Before treatment, lymphocytic gastritis was characterized by foveolar hyperplasia (P = 0.001) and glandular atrophy in the body (P = 0.008), and increased proliferation in both the body (P = 0.001) and antrum (P = 0. 002). Proliferation correlated with foveolar hyperplasia and inflammation activity. After eradication, the number of intraepithelial lymphocytes decreased in the body (P = 0.004) and antrum (P = 0.065), remaining higher than in controls (P < 0.001). Simultaneously, the proliferation index decreased in the body from 0.38 to 0.15 (P = 0.043), and in the antrum from 0.34 to 0.20 (P = 0.069), the antral index still being higher in lymphocytic gastritis than in controls (P = 0.010). Foveolar hyperplasia and glandular atrophy in the body improved (P = 0.021), reaching the non-LG level.

CONCLUSION: In lymphocytic gastritis, excessive epithelial proliferation is predominantly present in the body, where it associates with foveolar hyperplasia and glandular atrophy. These characteristic changes of lymphocytic gastritis are largely related to H pylori infection, as shown by their improvement after eradication. However, some residual deviation was still seen in lymphocytic gastritis, indicating either an abnormally slow improvement or the presence of some persistent abnormality.

In vivo and in vitro permeability in coeliac disease

BACKGROUND

An increased permeability to sugars is found in the intestine of untreated patients with coeliac disease after oral ingestion.

AIM

To test whether in vitro permeability resembles in vivo permeability tests and whether an in vitro gliadin gluten challenge could be performed by an in vitro permeability test.

METHODS

We measured in vivo (urinary excretion after sucrose-lactulose-mannitol ingestion) and in vitro permeability (by mini-Ussing chambers) in 25 healthy controls, 12 relatives of coeliac disease patients, 19 treated, eight partly treated and 16 untreated patients with coeliac disease.

RESULTS

In vivo sugar permeability was increased in nearly all coeliac patients. Additionally, in vitro permeability to lactulose (P=0.0007), mannitol (P=0.004) and sucrose (P=0.042) was higher in untreated patients with coeliac disease. It correlated with in vivo permeability (sucrose tau=0.61, P=0.006; lactulose tau=0.41, P < 0.0001; mannitol tau=- 0.56, P=0.62) and was dependent on mucosal damage. An in vitro gliadin challenge over 24 h could not significantly change in vitro permeability in treated patients with coeliac disease.

CONCLUSIONS

An in vitro permeability test capable of measuring elevated permeability in coeliac mucosa was described, but this test cannot replace oral gluten challenge by in vitro gliadin incubation.

Healing of lymphocytic gastritis by eradication of Helicobacter pylori

BACKGROUND

It is not yet clear whether lymphocytic gastritis might not be a sequela of Helicobacter pylori (Hp) infection. The aim of the present pilot study was, therefore, to investigate whether lymphocytic gastritis can be cured by Hp eradication, which, if affirmed, would provide indirect evidence for an etiopathogenic relationship.

PATIENTS AND METHODS

98 of 220 patients with lymphocytic gastritis diagnosed between 1988 and 1998 were investigated at least twice, with 61 of them undergoing Hp eradication treatment. In 29 of these patients, the pretreatment histological work-up using the Warthin-Starry silver stain revealed Hp colonisation, while in the remaining 32 patients the biopsies from the antrum and corpus were negative for Hp. The other 37 patients received no treatment, and served as a control group.

RESULTS

Both in the group with Hp-positive, and in the group with Hp-negative histology prior to treatment, eradication treatment led to healing of the gastritis, i.e. to regression of the gastritis parameters including normalisation of the intra-epithelial lymphocyte count, in 93.1% and 84.3% of the cases, respectively. In the control group the histological findings did not change.

CONCLUSIONS

The results of our retrospective study support the notion that most cases of lymphocytic gastritis might be a consequence of Hp infection. This, however, needs to be clarified definitively by a prospective, randomized, double-blind study.

TIA1 and mast cell tryptase in food allergy of children: increase of intraepithelial lymphocytes expressing TIA1 associates with allergy

BACKGROUND

Variability of symptoms and signs make the diagnosis of children's food allergy (FA) difficult. In addition, mechanisms and antigens involved vary with age. In young infants, cow's milk protein allergy is associated with an increase of cytotoxic intraepithelial lymphocytes (IELs) expressing T-cell-restricted intracellular antigen (TIA1). In the current study, the significance of TIA1 in FA in older children of mainly preschool and school age was analyzed and the findings correlated the with a detailed clinical, endoscopic, and histopathologic analysis.

METHODS

The subjects of this study were 66 children (mean age, 7.9 years; range, 1-15), including 27 with untreated and 15 with treated FA, and 24 control subjects. The morphology of duodenal and antral biopsy specimens was evaluated, and the proportion of TIA1-positive IELs was counted from immunostained sections. Quantification of mast cells with immunostaining for mast cell tryptase (MCT) was completed, with the estimation of diffuse extracellular staining considered to indicate degranulation.

RESULTS

Patients with untreated FA showed an increase in the total number of TIA1-positive cells and IELs and of the TIA1/IEL ratio. The number of mast cells in duodenal mucosa was decreased in children with FA, but no association with degranulation was observed. Endoscopic abnormalities were common in FA, but conventional histopathology showed no informative differences.

CONCLUSIONS

The significant increase of TIA1-positive IELs in duodenal tissue specimens is associated with FA. The cytotoxicity of T lymphocytes seems to play a role in the pathogenesis of gastrointestinal FA. Activation and mechanisms of action should be studied further.

[Histopathology of Helicobacter pylori infections]

Helicobacter pylori (H.p.) infection is associated in essentially all patients with a chronic active gastritis. According to the Houston-update of the Sydney classification grade and activity of the gastritis, the occurrence of intestinal metaplasia and atrophy as well as the density of H.p. colonization have to be semiquantitatively determined by the pathologists. Gastric acid production influences the severity of gastritis in antrum and body mucosa. In a subgroup of patients other forms of gastritis, such as lymphocytic gastritis, giant fold gastritis and atrophic gastritis may develop. After eradication plasma cells may persist in the lamina propria for years.

Granzyme B-positive primary gastric T-cell lymphoma: gastric T-cell lymphoma with the possibility of extrathymic T cell origin

A case of primary gastric T-cell lymphoma, which was positive for granzyme B, is reported. The patient was a 47-year-old Japanese female who complained of a dull upper abdominal pain. Radiographic and endoscopic examinations revealed an ulcerative infiltrative lesion in her stomach. Following the confirmation of a high-grade malignant lymphoma, a distal gastrectomy with regional lymph nodal dissection was performed. The histology of the gastric lesion revealed a malignant lymphoma of the diffuse pleomorphic type without lymph nodal involvement. Immunohistochemistry revealed that the tumor cells were positive for LCA, CD3, TIA-1 and granzyme B, but were negative for CD4, CD8, CD56, CD30, L-26, EMA, TCR alpha/beta and TCR gamma/delta. Because the tumor cells showed T cell nature with cytotoxic activity proved by TIA-1 and granzyme B, and without evidence of further maturation of T cell, a malignant lymphoma originating from extrathymic-derived T cells was suggested.

Histopathology of celiac disease

The diagnosis of celiac disease (CD) is based upon histologic findings in duodenal or jejunal biopsies. In the past few years it has turned out that the development of CD lesion in the small bowel is a dynamic process which may present in various histologic forms. At one end of the spectrum is a mucosa with normal architecture and an increase in intraepithelial lymphocytes (IEL), at the other end is the classical flat mucosa. Histologic features supporting the diagnosis of CD are architectural changes of the villi and/or crypts, an increase in lamina propria cell density and an increase in IEL counts. For diagnostic purposes and for monitoring CD patients an exact histologic classification of the histologic findings has to be given. This has become possible by using a modified Marsh classification. In the present paper the histologic presentation of CD is presented as well as the modified Marsh classification.

Lymphocyte predominance Hodgkin's disease: the use of bcl-6 and CD57 in diagnosis and differential diagnosis

Distinction of lymphocyte predominance Hodgkin's disease (LPHD) from other forms of lymphoma often requires immunohistochemistry (IHC). Most previously published recommended panels include markers to define the large neoplastic cells (for example, CD20, J chain, CD45) as well as the non-neoplastic background cells (CD21, CD45RO, CD57, TiA 1). In the present study we examine the practical use of a double IHC method designed to look simultaneously at two germinal center specific cell types: bcl6+ cells and [bc16+, CD57+] co-positive cells. All 10 nodular LPHD had bcl6+ large cells and numerous CD57+ small background cells, including [bcl6+CD57+] cells in rosettes. One case of LPHD with large cell transformation contained numerous bcl6+ large cells both singly (in areas of typical LPHD) and in sheets (in foci of large cell transformation), many CD57+ small cells but few [bcl6+CD57+] co-positive cells and no rosettes. In none of the five cases of florid progressive transformation of germinal centers were true rosettes seen, although all contained variable numbers of bcl6+ large cells and CD57+ cells. Lymphocyte-rich classic Hodgkin's disease LRCHD cases were notable for bcl6 reactivity in Reed-Sternberg cells in all cases, numerous background small bcl6+ lymphocytes, and rare CD57+ cells. Two phenotypic profiles were associated with the 10 cases of T cell-rich B cell large cell lymphoma (TCRBCL). In the first, group "A," six of six cases had bc16- large cells and few CD57+ small cells, and none had significant numbers of [bcl6+, CD57+] co-positive cells. In the second, group "B," four of four cases had bcl6+ large cells with numerous CD57+ and [bcl6+, CD57+] co-positive cells. These findings not only show that LPHD can be distinguished from its morphologic mimics through identification of specific germinal center cell types, but also identifies a second group of TCRBCL (group "B") whose phenotype suggests it might be an architectural variant of nodular LPHD.

The pattern of involvement of the gastric mucosa in lymphocytic gastritis is predictive of the presence of duodenal pathology

AIM

To determine whether the pattern of involvement of the gastric mucosa in lymphocytic gastritis is predictive of the presence or absence of duodenal pathology.

METHODS

50 cases (M:F, 26:24; median age 57 years) diagnosed as lymphocytic gastritis between 1986 and 1998 with concurrent duodenal (D2) biopsies were identified from a computer search of the pathology records and validated by counting gastric intraepithelial lymphocytes. Gastric and duodenal intraepithelial lymphocyte counts were performed on haematoxylin and eosin (H&E) and anti-CD3 stained sections. D2 biopsies were assessed for villous atrophy and chronic inflammatory cell infiltration by subjective grading, and gastritis was classified and graded according to the updated Sydney system. A case was designated corpus predominant when the corpus chronic inflammation grade exceeded that of the antrum. If it was less, then the case was antrum predominant, and if they were equal it was diffuse (pan-) gastritis. The ratio between the corpus and antral intraepithelial lymphocyte count in individual patients was calculated.

RESULTS

Of 50 cases of lymphocytic gastritis, 21 were classified as corpus predominant. With one exception (a case of mild villous atrophy), all were accompanied by normal duodenal morphology. Cases with a corpus predominant gastritis had median duodenal intraepithelial lymphocyte counts of 19 (H&E) and 14.1 (CD3), whereas 29 subjects with an antrum predominant or diffuse gastritis had median counts of 39.9 (H&E) and 37.9 (CD3). Fifteen of these 29 cases (52%) showed villous atrophy; all were graded as moderate or severe. Patients with any degree of villous atrophy had a mean corpus/antrum intraepithelial lymphocyte ratio (H&E) of 0.59 (representing antral predominance), while those with normal duodenal morphology had a ratio of 2.39 (p < 0.0001).

CONCLUSIONS

The pattern of involvement of gastric mucosa in lymphocytic gastritis is closely related to the associated duodenal pathology. Those with the corpus predominant form are unlikely to have duodenal pathology, while those with an antral predominant or diffuse form should have distal duodenal biopsies taken to exclude villous atrophy.

Aberrant esophageal HLA-DR expression in a high percentage of patients with Crohn's disease

Esophageal histology is not well studied in patients with Crohn's disease (CD). We, therefore, analyzed the histologic and immunohistologic appearance of esophageal mucosa in CD. Biopsy specimens taken from the esophagus of 57 consecutive patients with known CD of the large and/or small bowel, of 200 Crohn's-free controls, of 15 cases with ulcerative colitis, and of 5 cases with viral esophagitis were evaluated. In controls, most patients had either HLA-DR negative esophageal epithelium or showed focal or diffuse basal staining. HLA-DR expression of all epithelial layers (transepithelial staining) was observed in only four (2%) control subjects, in one case with herpes esophagitis, but not in patients with ulcerative colitis. In contrast, transepithelial HLA-DR expression was found in 19 (33%) patients with CD (p < 0.0001). In CD patients, it was associated with a significantly increased epithelial content in T-cells (CD3+, TIA-1+, granzyme B+), B-cells (CD79a+), natural killer cells (CD57+), and macrophages (CD68+). There was no correlation with either histological findings elsewhere in the upper gastrointestinal tract or with laboratory findings, symptoms, CDAI, or medication. Transepithelial esophageal HLA-DR expression is common in CD. Immunohistochemistry may prove useful in supporting the histologic diagnosis of CD in staging procedures, for initial diagnosis as well as in doubtful cases.

Assessment and diagnostic utility of the cytotoxic T-lymphocyte phenotype using the specific markers granzyme-B and TIA-1 in esophageal mucosal biopsies

Most esophageal intraepithelial lymphocytes (IELs) express T-cell markers. Increased numbers of esophageal IELs have been shown in reflux esophagitis. The cytotoxic potential and activity of esophageal IELs have not as yet been examined. Our objectives were to determine whether esophageal IELs express the recently described cytotoxic T-cell (CTLs) markers, TIA-1 and granzyme-B, and whether the number of CTLs correlates with well-defined endoscopic, clinical, and histological features of esophagitis. In this study, most CD-3+ esophageal IELs exhibit the CD-8+/TIA-1+ T cell with cytotoxic potential phenotype in both histologically normal biopsy specimens and in biopsy specimens with esophagitis. A subpopulation of esophageal IELs that express cytotoxic activity was identified by granzyme-B immunostaining. A significant positive association was found between the number of esophageal IELs seen by light microscopy in biopsy specimens with histological features of reflux (21 IELs/HPF) and Candida esophagitis (31 IELs/HPF) as compared with normal-appearing biopsy specimens (10 IELs/HPF) (P< or =.05). Furthermore, the number of TIA-1 or granzyme-B-positive IELs were significantly increased in biopsy specimens with reflux esophagitis (34 and 15 cells/HPF) and Candida esophagitis (44 and 18 cells/HPF) as compared with normal (11 and 2 cells/HPF) (P< or =.05). Granzyme-B and CD-3-positive IELs were also significantly elevated in biopsy specimens with reflux-associated squamous hyperplasia (P< or =.05). Finally, biopsy specimens of patients with dysphagia and to a lesser extent dyspepsia/heartburn exhibited increased numbers of IELs bearing the cytotoxic phenotype when compared with asymptomatic patients. In conclusion, we provide immunohistochemical evidence that most esophageal IELs exhibit the cytotoxic phenotype and that activated cytotoxic IELs are increased in reflux and Candida esophagitis.

Lymphocytic gastritis: association with etiology and topology

Lymphocytic gastritis (LG) is an uncommon chronic gastritis characterized by lymphocytosis of foveolar and surface epithelium. Lymphocytic gastritis is associated with celiac disease, Helicobacter pylori (HP) gastritis, and varioliform gastritis, but its topology and severity with respect to the associated entities have not been studied in detail. Therefore, we studied 103 patients with LG classified according to the associated entities, including the distribution and severity of LG in the 70 patients from whom biopsy specimens of both antrum and body were available. In 84 patients (82%), a distinct associated entity was identified, including 39 with celiac disease, 30 with HP infection, 4 with varioliform gastritis, 2 each with inflammatory polyp, Crohn's disease, human immunodeficiency virus infection, lymphoma, and esophageal carcinoma, and 1 with lymphocytic gastroenterocolitis. Lymphocytic gastritis was found in 33% of patients with celiac disease and 4.1% of histopathologically defined HP gastritis. The severity of intraepithelial lymphocytosis was greater in antrum than in body in 83% (20 of 24) of LG associated with celiac disease, but in only 19% (4 of 21) of LG associated with HP infection (p < 0.00002). All four patients with varioliform gastritis had more severe involvement of body. Lymphocytic colitis was common (38%, 5 of 13) in celiac disease with LG. Our results indicate that lymphocytic gastritis most commonly occurs in celiac disease and HP infection, but rarely with other entities. The topology of LG can direct the clinical evaluation for associated disease.

In vitro model of the pathogenesis of celiac disease

The in vitro challenge of duodenal mucosa with gliadin is a useful model to reproduce the immunological features of celiac disease (CD) and allows the study of early pathogenetic events in this disease. With this model it was shown that antigens such as ICAM-1 and HLA-DR are upregulated as early as 1-2 h after gliadin challenge in patients with CD. After 24 h the lamina propria contained CD4+ T cells expressing the IL-2 receptor alpha-chain, which is a sign of activation. Intraepithelial lymphocytes increased in number and showed proliferative activity. After in vitro stimulation with gliadin, endomysial antibodies were found in the supernatant of the cultured mucosa from patients with CD following a gluten-free diet. This supported the notion that endomysial antibodies are at least in part produced locally. The model was also successfully used to identify toxic constituents of gliadin. Presently, organ culture is not commonly used for diagnostic purposes.