BACKGROUND—Lymphocytic gastritis is characterised by an accumulation of lymphocytes in the surface epithelium of the stomach. Lymphocytic gastritis has been linked to coeliac disease and Helicobacter pylori infection.
AIMS—To determine whether H pylori eradication leads to resolution of the lymphocytic infiltrate and clinical improvement in patients with lymphocytic gastritis, and to determine their HLA status.
METHODS—The Leeds Dyspepsia Questionnaire (LDQ) was administered to 13 patients with lymphocytic gastritis. H pylori serology, 13C urea breath test (UBT), and upper gastrointestinal endoscopy with sampling of the duodenum, antrum, and corpus were done in all cases and the HLA status was determined. Eleven patients had at least one positive test for H pylori. Patients with lymphocytic gastritis and H pylori infection were treated with a one week course of omeprazole, clarithromycin, and metronidazole. Gastric and duodenal intraepithelial lymphocyte (IEL) counts were performed, along with histological assessment of gastric and duodenal biopsies before and after H pylori eradication.
RESULTS—Two months after treatment there was a significant reduction in gastric IEL counts in both antrum and corpus. There was no significant change in duodenal IEL counts before and after eradication. According to the Sydney grading there was significant improvement in corpus inflammation after eradication. The patients histologically H pylori positive before treatment became H pylori negative. Dyspepsia scores also improved significantly after treatment.
CONCLUSIONS—H pylori eradication treatment in patients with lymphocytic gastritis causes significant improvement in the gastric IEL infiltrate, corpus inflammation, and dyspeptic symptoms. H pylori serology is frequently positive when histology and UBT are negative. Lymphocytic gastritis may represent a specific immune response to H pylori infection.
Keywords: lymphocytic gastritis; intraepithelial lymphocytes; Helicobacter pylori; HLA status; coeliac disease
Helicobacter pylori infection is associated with chronic gastritis, peptic ulceration, and gastric carcinoma. The potential role of CD95-mediated apoptosis was investigated in a panel of gastric biopsies obtained from patients with H. pylori-associated chronic gastritis (n = 29) and with noninfected normal mucosa (n = 10). Immunohistochemistry revealed increased CD95 receptor expression in epithelial and lamina propria cells in chronic gastritis. By in situ hybridization, CD95 ligand mRNA was absent or low in normal mucosa but expressed at high levels in lamina propria lymphocytes and, unexpectedly, in epithelial cells in chronic gastritis. Apoptotic cells were rare in normal mucosa but were observed regularly in chronic gastritis in close proximity to CD95 ligand mRNA expression throughout the epithelial and lamina propria cells. In a functional analysis gastric epithelial cell lines were incubated with supernatants of H. pylori. Treatment with the cytotoxic isolate H. pylori 60190 but not with the noncytotoxic isolate Tx30a upregulated CD95 in up to 50% of gastric epithelial cells and induced apoptosis in these cells. H. pylori-induced apoptosis was partially prevented by blocking CD95, demonstrating the functional role of the CD95 system. These findings suggest that H. pylori-associated chronic gastritis involves apoptosis of gastric epithelial cells by activation of the CD95 receptor and ligand system.
AIM--To evaluate the histological changes that occur in the antral mucosa of healthy male subjects before and after one week of naproxen administration, using a chemical gastritis score according to the Helicobacter pylori status. METHODS--Nineteen male subjects (mean age 31 years) underwent two endoscopies: one before and the other after one week of naproxen treatment (1 g daily). Antral biopsy specimens were assessed for the presence of H pylori infection and for chemical gastritis, defined as the presence of foveolar hyperplasia, muscle fibres in the lamina propria, oedema, and vasodilatation, in the absence of acute or chronic inflammatory cell infiltrate. RESULTS--Of the 19 subjects, eight had H pylori infection. After one week of naproxen treatment, none of those with H pylori infection developed chemical gastritis, while five of 11 (45%) of those without H pylori infection did. In the absence of H pylori infection there was no evidence of inflammation, either before or after naproxen administration. CONCLUSIONS--A different pattern of antral histological change occurs following naproxen administration. This pattern is related to the presence or absence of H pylori infection, suggesting that H pylori status should be determined in histological studies of subjects taking non-steroidal anti-inflammatory drugs.
Background: Refractory coeliac sprue (RCS) with an immunophenotypically aberrant clonal intraepithelial lymphocyte (IEL) population is considered a cryptic form of intestinal T cell lymphoma.
Aims: To investigate the distribution of the abnormal and monoclonal IEL population in the digestive tract of RCS patients.
Patients and methods: We compared the frequency of lymphocytic gastritis (LG) and lymphocytic colitis (LC), together with IEL phenotype and T cell clonality, in gastric and colonic samples from 15 adults with RCS (all with aberrant CD3 intracytoplasmic+ surface− CD8− clonal IELs on duodenojejunal biopsies), 18 patients with active coeliac disease (ACD), and 10 patients with coeliac disease (CD) on a gluten free diet (GFD-CD) by means of immunohistochemistry and multiplex polymerase chain reaction amplification of the T cell receptor γ gene (TCR-γ) rearrangement. Blood samples of nine RCS patients were also tested for clonality.
Results: LG was found in 9/14 (64%), 11/18 (61%), and 3/10 (30%) patients with RCS, ACD, and GFD-CD, respectively, while LC was found in 6/11 (55%), 3/4 (75%), and 2/3 (66%) patients. Contrary to CD, all samples from patients with LG and LC showed an aberrant IEL phenotype. Monoclonal TCR-γ rearrangements were detected in 8/13 (62%), 8/10 (80%), and 4/9 (44%) of gastric, colonic, and blood samples, respectively, from RCS patients, while in CD patients such rearrangements were only found in 2/25 (8%) gastric samples.
Conclusion: The immunophenotypically aberrant monoclonal IEL population present in the small intestine of patients with RCS frequently disseminates to the blood and the entire gastrointestinal epithelium, suggesting that this is a diffuse gastrointestinal disease.
enteropathy-type intestinal T cell lymphoma; lymphocytic gastritis; lymphocytic colitis; coeliac disease; refractory sprue; T cell receptor gene rearrangement
AIM: To determine associations between enterogastric bile reflux and gastric mucosal pathology. METHOD: A retrospective study using fasting gastric juice bile acid measurements and antral or prestomal biopsy specimens from 350 patients, 66 of whom had previously undergone surgery that either bypassed or disrupted the pyloric sphincter. RESULTS: Bile reflux was positively associated with reactive gastritis and negatively with Helicobacter pylori density. After stratification for previous surgery, age, and H pylori status, the histological feature most strongly associated with bile reflux was intestinal metaplasia, including all its subtypes. The prevalence of intestinal metaplasia was greatest in patients with both H pylori infection and high bile acid concentrations. Bile reflux was also positively associated with the severity of glandular atrophy, chronic inflammation, lamina propria oedema and foveolar hyperplasia. CONCLUSIONS: Bile reflux is a cause of reactive gastritis. It modifies the features of H pylori associated chronic gastritis. The changes are not confined to patients who have had surgery to their stomachs. The positive associations with atrophy and intestinal metaplasia have implications for models of gastric carcinogenesis.
Colonization of the gastric mucosa with Helicobacter pylori is associated with a dense infiltration of granulocytes into the lamina propria in the active phase of gastritis. In this study, we investigated the involvement of epithelial cell-derived neutrophil-activating protein 78 (ENA-78) in development of H. pylori-associated gastritis. Antral biopsies from 27 patients with H. pylori-associated gastritis and 25 from H. pylori-negative individuals were first analyzed for ENA-78 and interleukin-8 (IL-8) mRNA by semiquantitative reverse transcription (RT)-PCR. In H. pylori-positive patients, significantly elevated levels were found for both chemokines (P < 0.05). Only IL-8 mRNA levels differed significantly (P < 0.05) in H. pylori-infected individuals who had serum antibodies for cytotoxin-associated protein CagA versus H. pylori-infected CagA-negative persons. Quantification of ENA-78 transcript levels by competitive RT-PCR yielded a significant 45-fold upregulation for ENA-78 transcripts in biopsies of H. pylori-positive versus H. pylori-negative patients (P < 0.05). In contrast to earlier findings with IL-8, the degree of ENA-78 mRNA upregulation was independent of the grade of activity of gastritis. Immunofluorescence studies on tissues of antral biopsies localized ENA-78 protein expression mainly to the gastric epithelium of H. pylori-positive patients, while control tissues were negative. Upregulation of ENA-78 and IL-8 mRNA and protein expression was also observed in an in vitro system using a gastric adenocarcinoma cell line. Only viable H. pylori yielded a strong ENA-78 and IL-8 induction, while H. pylori outer membrane proteins or water-soluble proteins had no significant effect. These data provide evidence for the importance of both IL-8 and ENA-78 in the development and perpetuation of H. pylori-associated gastritis.
Oral infection of C57BL/6 mice with Toxoplasma gondii triggers severe necrosis in the ileum within 7–10 days of infection. Lesion development is mediated by Th-1 cytokines, CD4+ T cells, and sub-epithelial bacterial translocation. As such, these features share similarity to Crohn’s disease. Recently, we uncovered a role for intraepithelial lymphocytes (IEL) in mediating pathology after Toxoplasma infection. We show here that αβ and not γδ T cell IELs mediate intestinal damage. By adoptive transfer of mucosal T cells into naive Rag1−/− mice, we demonstrate that IEL do not function alone to cause inflammatory lesions, but act with CD4+ T lymphocytes from the lamina propria. Furthermore, recipient mice pretreated with broad-spectrum antibiotics to eliminate intestinal flora resisted intestinal disease after transfer of IEL and lamina propria lymphocytes. Our data provide valuable new insight into mechanisms of intestinal inflammation, findings that have important implications for understanding human inflammatory bowel disease.
BACKGROUND—Keratinocyte growth factor (KGF) stimulates gastrointestinal epithelial cells in vivo, and is protective against gastrointestinal injury and colitis. Endogenous KGF is increased in inflammatory bowel disease (IBD), and may be an important mediator of mucosal repair. KGF is expressed by mesenchymal cells and activated intraepithelial lymphocytes (IEL).
AIMS—To investigate the relative contributions of these cellular sources of KGF expression in IBD.
METHODS—IELs and lamina propria lymphocytes (LPL) were isolated from inflamed and uninflamed IBD tissues. mRNA expression was determined by ribonuclease protection assay. In situ hybridisation was combined with immunohistochemistry to determine whether KGF mRNA was expressed by specific cell types in vivo.
RESULTS—Low levels of KGF mRNA expression were detected in three of five IEL samples derived from inflamed tissue, but not in two IEL samples from uninflamed tissue. No KGF expression was detected in LPLs from either inflamed or uninflamed tissue. In contrast, KGF was expressed by primary cultures of human intestinal fibroblasts, and was induced by treatment with interleukin 1.
CONCLUSIONS—The major source of KGF expression in IBD was lamina propria cells of non-immune origin, most likely fibroblasts and/or smooth muscle cells. Compared with these cell types, relatively little KGF synthesis was associated with IELs in inflamed IBD tissue.
Keywords: fibroblasts; intestinal inflammation; intraepithelial lymphocytes; keratinocyte growth factor; lamina propria lymphocytes
Lymphocyte subpopulations in the intestinal mucosa of patients with ulcerative colitis or Crohn's disease have been studied using a double marker immunofluorescence technique. Analysis of tissue sections revealed that the majority of intraepithelial lymphocytes (IEL) were T cells (Hle-1+ HuTLA+ UCHT1+). Of these, over 80% were of suppressor-cytotoxic phenotype (OKT8+:83 +/- 10.2%) with a small population of helper type IEL (OKT4+). Only one third of OKT8+ IEL reacted with the T cell antibody, anti-Leu-1. IEL were also Tac-, C3b-receptor- (C3RT05-), and Ig-. Within the lamina propria, OKT4+ T cells predominated (ulcerative colitis 64 +/- 6.0%; Crohn's disease 63 +/- 6.0%). Less than half of the smaller OKT8+ population in the lamina propria was Leu-1+. These finding did not differ from those seen in histologically normal tissues from controls, and are similar to those reported in the small intestine. Mononuclear cells were also isolated from the intestinal lamina propria using an enzymatic technique. The majority of lymphocytes obtained were T cells (OKT3+), with populations of OKT4+ and OKT8+ cells. Comparison of the ratio of OKT4+ to OKT8+ lymphocytes determined by immunohistological analysis with that obtained in mucosal isolates, however, suggested that the isolation procedure may deplete OKT8+ cells. These findings indicate that an imbalance of mucosal immunoregulatory T cells, as defined by monoclonal antibodies, does not occur in inflammatory bowel disease. They also emphasize that functional studies of isolated intestinal mucosal cells should be combined with morphological studies of cell populations in situ.
The present study shows that the distribution of T lymphocytes in gastrointestinal carcinomas and their metastases mimic the distribution of T lymphocytes in normal intestine. The composition of the peritumoral reaction resembled that of normal lamina propria with a predominance of CD3 + CD4 + T cells. In contrast, lymphocytes located between carcinomatous cells showed phenotypical features similar to those of intraepithelial lymphocytes (IEL) in normal intestine; in particu(abstractlar they expressed the antigen defined by HML-1, a monoclonal antibody raised against normal human intestinal IEL which reveals 95% IEL but very few cells in lymphoid (abstractorgans and blood. As normal intestinal IEL, the majority of intratumoral lymphocytes had the CD3+ CD8+ phenotype. A panel of monoclonal antibodies and double immunostaining techniques permitted a better characterisation of minor subsets of IEL. Two subsets of HML1 + CD3 + CD4- CD8- and of HML1+ CD3- cells, representing 2% and 3% of normal intestinal IEL respectively, did not significantly increase in carcinomatous epithelium. In contrast, in carcinomatous epithelium, but not in normal intestinal epithelium, we observed the appearance of a few lymphocytes displaying the phenotype of activated T cells (CD25+) or of natural killer cells (NKHI+) or of suppressor cells (CD11+). Such cells may participate in antitumoral defence. Although a similar population of HML1+ lymphocytes is associated with normal and carcinomatous intestinal epithelium, some interactions between lymphocytes and epithelial cells may not be maintained in tumoral epithelium. It has previously been shown that HLA-DR expression by enterocytes is modulated by intraepithelial lymphocytes. In our study, no correlation could be shown between the degree of lymphocytic infiltration and the expression of HLA-DR antigens on carcinomatous cells.
Background: Gastrin G cells and somatostatin D cells are important regulators of gastric acid secretion and alterations in their relative numbers may play a key role in gastroduodenal disease.
Aim: To investigate the effect of Helicobacter pylori infection on the density of immunoreactive G and D cells in gastric antral and corpus biopsies from patients with dyspeptic complaints.
Methods: One hundred and twenty two patients with dyspeptic complaints had two antrum and two corpus biopsies taken during upper endoscopy. The severity of inflammation and the density of H pylori were evaluated semiquantitatively. In addition, the density and distribution of neuroendocrine cells, especially G and D cells, were examined using immunohistochemistry. Patients were divided into three groups, those with H pylori positive gastritis, H pylori negative gastritis, and histologically normal gastric mucosa.
Results: The number of immunoreactive G cells was significantly higher and the number of immunoreactive D cells lower in patients with H pylori positive gastritis compared with H pylori negative gastritis or histological normal gastric mucosa. The percentage of G cells as a percentage of mucosal endocrine cells was also raised and that of D cells was decreased.
Conclusions: Helicobacter pylori infection produces alterations in the number of endocrine cells responsible for regulating acid secretion in relation to intragastric pH and feeding. The alterations correlate best with the severity of inflammation and not with H pylori density.
gastritis; Helicobacter pylori; gastrin; somatostatin; chromogranin
AIMS: To evaluate the effect of 10 day triple treatment on H pylori eradication and associated gastritis. METHODS: Fifty patients with H pylori positive non-ulcer dyspepsia were treated for 10 days with amoxicillin, tinidazole, and bismuth salts. Histological examination of the antral mucosa was performed before (T0), six weeks (T1), and six months (T2) after treatment. The new Sydney classification of gastritis was used, using a score from 0 to 3 to grade degree of inflammation, atrophy, activity (intraepithelial or lamina propria damage) and H pylori. RESULTS: At T0 all patients had chronic active gastritis. Lymphoid follicules were present in 12 cases. At T1 33 patients were H pylori negative: the score showed a decrease of activity (from 2.5 to 0.54). The result was confirmed at T2 (mean score 0.22). Inflammation decreased from 1.8 to 1.4 at T2. Only one case of follicular gastritis was observed. In H pylori positive patients the scores did not show significant modifications. CONCLUSIONS: Ten day triple treatment is effective in eradicating H pylori in 69% of cases, causing a decrease of the total score for gastritis. Activity, defined by polymorph infiltration, was promptly reduced when H pylori was eradicated. There was a trend to a reduction in inflammation, but atrophy was irreversible.
The aim of this study was to investigate the pathologic characteristics of nodular gastritis in children and young adults infected with Helicobacter pylori (H. pylori).
Materials and Methods
A total of 328 patients were enrolled in this study, and the diagnosis of H. pylori infection was done with gastroduodenal endoscopy concomitant with a CLO™ test and pathologic analysis of the biopsy specimens. Diagnoses of normal, superficial gastritis, nodular gastritis, and peptic ulcer disease were made from the gastroduodenal endoscopic findings. The density of H. pylori organisms in the gastric mucosa was rated as normal, mild, moderate, or marked. The pathologic findings of nodular gastritis were based on the histopathologic findings of inflammation, immune activity, glandular atrophy and intestinal metaplasia. Each of these findings was scored as either normal (0), mild (1), moderate (2), or marked (3) according to the updated Sydney system and using visual analog scales. The gastritis score was the sum of the four histopathologic scores.
In this study, nodular gastritis (50.6%) was most common, and mild density (51.5%) H. pylori infection was also common upon microscopic examination. Intestinal metaplasia occurred in 9 patients (2.7%).
Logistic regression revealed a significant increase in the incidence of nodular gastritis with gastritis score (p = 0.008), but not an association with sex, age, or H. pylori density. Gastritis score was the only significant factor influencing the occurrence of nodular gastritis. Intestinal metaplasia, which was originally thought to be a pre-malignant lesion, occurred in 2.7% of the patients with H. pylori infection.
Helicobacter pylori; updated Sydney system; nodular gastritis; gastritis score
Intraepithelial lymphocytes (IELs) bearing the γδ TCR are more abundant in the small intestinal mucosa of patients with celiac disease (CD) compared with healthy individuals. However, their role in disease pathogenesis is not well understood. Here, we investigated the functional attributes of TCRγδ+ IELs isolated from intestinal biopsies of patients with either active celiac disease (ACD) or those on a gluten-free diet (GFD). We found that compared with individuals with ACD, individuals on GFD have a higher frequency of CD8+TCRγδ+ IELs that express the inhibitory NK receptor NKG2A and intracellular TGF-β1. TCR triggering as well as cross-linking of NKG2A increased both TGF-β1 intracellular expression and secretion in vitro. Coculture of sorted TCRγδ+NKG2A+ IELs, IL-15–stimulated TCRαβ+ IELs, and HLA-E+ enterocytes resulted in a decreased percentage of cytotoxic CD8+TCRαβ+ IELs expressing intracellular IFN-γ and granzyme-B and surface NKG2D. This inhibition was partially abrogated by blocking either TGF-β alone or both NKG2A and HLA-E. Thus, our data indicate that suppression was at least partially mediated by TGF-β secretion as a result of engagement of NKG2A with its ligand, HLA-E, on enterocytes and/or TCRαβ+ IELs. These findings demonstrate that human small intestinal CD8+TCRγδ+ IELs may have regulatory potential in celiac disease.
AIM: To determine the expression of DNA (MMR) proteins, including hMLH1 and hMSH2, in gastric epithelial cells in the patients with or without Helicobacter pylori (H pylori)-infected gastritis.
METHODS: Fifty H pylori-positive patients and 50 H pylori-negative patients were enrolled in the study. During endoscopy of patients with non-ulcer dyspepsia, two antral and two corpus biopsies were taken for histological examination (Giemsa stain) and for immunohistochemical staining of hMLH1 and hMSH2.
RESULTS: The percentage of epithelial cell nuclei that demonstrated positivity for hMLH1 staining was 84.14 ± 7.32% in H pylori-negative patients, while it was 73.34 ± 10.10% in H pylori-positive patients (P < 0.0001). No significant difference was seen between the two groups regarding the percentage of epithelial cell nuclei that demonstrated positivity for hMSH2 staining (81.16 ± 8.32% in H pylori-negative versus 78.24 ± 8.71% in H pylori-positive patients; P = 0.09).
CONCLUSION: This study indicates that H pylori might promote development of gastric carcinoma at least in part through its ability to affect the DNA MMR system.
Helicobacter pylori; DNA mismatch repair; hMLH1, hMSH2
Helicobacter pylori is a Gram-negative bacterium that infects over 50% of the world's population. This organism causes various gastric diseases such as chronic gastritis, peptic ulcer, and gastric cancer. H. pylori possesses lipopolysaccharides that share structural similarity to Lewis blood group antigens in gastric mucosa. Such antigenic mimicry could result in immune tolerance against antigens of this pathogen. On the other hand, H. pylori colonizes gastric mucosa by utilizing adhesins that bind Lewis blood group antigen-related carbohydrates expressed on gastric epithelial cells. After colonization, H. pylori induces acute inflammatory responses mainly by neutrophils. This acute phase is gradually replaced by a chronic inflammatory response. In chronic gastritis, lymphocytes infiltrate the lamina propria, and such infiltration is facilitated by the interaction between L-selectin on lymphocytes and peripheral lymph node addressin (PNAd), which contains 6-sulfo sialyl Lewis X-capped O-glycans, on high endothelial venule (HEV)-like vessels. H. pylori barely colonizes gland mucous cell-derived mucin where α1,4-GlcNAc-capped O-glycans exist. In vitro experiments show that α1,4-GlcNAc-capped O-glycans function as a natural antibiotic to inhibit H. pylori growth. These findings show that distinct sets of carbohydrates expressed in the stomach are closely associated with pathogenesis and prevention of H. pylori-related diseases, providing therapeutic potentialities based on specific carbohydrate modulation.
6-sulfo sialyl Lewis X-capped O-glycan; α1, 4-GlcNAc-capped O-glycan; cholesterol α-glucoside; cholesterol α-glucosyltransferase; Helicobacter pylori
AIMS--To determine the prevalence of lymphoid follicles in Helicobacter pylori positive and negative gastritis in antral and body type gastric mucosa in patients with non-ulcer dyspepsia (NUD), duodenal ulcer, or gastric ulcer; to correlate follicle presence with patient age; to evaluate the correlation between the prevalence of lymphoid follicles and active and inactive gastritis and its severity; and to assess the positive predictive value of lymphoid follicle prevalence with respect to H pylori infection. METHODS--Gastric biopsy specimens, graded according to the Sydney system, from 337 patients were studied. RESULTS--Lymphoid follicles occurred more often in antral mucosa (78%) than in body type mucosa (41%) and were observed in 85% of patients with H pylori positive gastritis. There was no significant difference between NUD and gastric and duodenal ulcer disease with regard to the presence of lymphoid follicles. The positive predictive value of the presence of lymphoid follicles in H pylori infection was 96%. Lymphoid follicles were more commonly observed in patients aged between 10 and 29 years. Lymphoid follicles were more frequently found in pangastritis of all subtypes than in antral gastritis and also in active gastritis than in inactive gastritis. The presence of lymphoid follicles correlated strongly with the degree and severity of gastritis. CONCLUSION--Lymphoid follicles are a constant morphological feature of H pylori associated gastritis.
BACKGROUND—Lamina propria (LPLs) and intraepithelial (IELs) lymphocytes are markedly increased in coeliac mucosa, and are thought to play a crucial role in the generation of villous atrophy in coeliac disease (CD). However, the mechanisms by which they mediate the killing of enterocytes in this condition are still poorly characterised.
AIM—We investigated Fas mediated cytotoxicity and apoptosis of both LPLs and IELs, isolated from 10 untreated coeliac patients, 10 coeliac patients on a gluten free diet, and 10 biopsied controls.
METHODS—Fas and Fas ligand expression were assessed by flow cytometry and immunocytochemistry. Lymphocyte cytotoxicity against Fas expressing Jurkat cells was determined by the Jam test. The effect of the antagonist ZB4 anti-Fas antibody on apoptotic activity exerted by coeliac lymphocytes against enterocytes was analysed. Lymphocyte apoptosis was assessed by oligonucleosome ELISA.
RESULTS—LPLs and IELs showed increased apoptotic activity and higher levels of Fas ligand expression in untreated CD compared with treated CD patients and controls. Enterocyte apoptosis observed after coculturing coeliac lymphocytes and enterocytes in the presence of ZB4 antibody was reduced. In active CD, LPLs manifested increased apoptosis whereas IELs showed decreased apoptosis.
CONCLUSIONS—Our results support the involvement of the Fas/Fas ligand system in CD associated enterocyte apoptosis. Increased LPL apoptosis is likely to downregulate mucosal inflammation whereas decreased IEL apoptosis could be responsible for autoimmune and malignant complications of CD.
Keywords: apoptosis; coeliac disease; cytotoxicity assay; Fas/Fas ligand system; intraepithelial lymphocytes; lamina propria lymphocytes
Background and aims
Epithelium derived interleukin (IL)‐15 signalling via IL‐15Rα is critical for the development, activation, and survival of intraepithelial lymphocytes (IEL). We aimed to better understand the IL‐15 driven effects on IEL underlying mucosal damage and lymphomagenesis in coeliac disease (CD).
Enterocytes, IEL, and lamina propria mononuclear cells (LPMC) were isolated from 46 patients with uncomplicated CD (25 untreated and 21 treated) and 22 controls. IL‐15 and IL‐15Rα expression were determined by immunoblotting. Secretion of IL‐15, interferon γ (IFN‐γ), tumour necrosis factor α (TNF‐α), and granzyme B into cell culture supernatants was assessed by ELISA. The ability of IL‐15 to regulate IEL proliferation, perforin/granzyme dependent cytotoxicity, and apoptosis was tested by adding different combinations of IL‐15, IL‐15 blocking antibody, or chloroquine to IEL cultured alone or with Caco‐2 cells as target. IL‐15 mucosal levels were also determined by ELISA in five patients with complicated CD (two ulcerative jejunoileites, one refractory sprue, and two enteropathy associated T cell lymphomas) tested for T cell receptor γ chain clonality.
IL‐15 was overexpressed in untreated CD enterocytes and LPMC, and in the mucosa of complicated CD patients and uncomplicated untreated CD patients, where its levels correlated with the degree of mucosal damage. Enterocytes from untreated, but not treated, CD patients and controls secreted IL‐15. Untreated CD IEL, characterised by higher IL‐15Rα expression, showed increased proliferation, production of IFN‐γ and TNF‐α, and perforin/granzyme dependent cytotoxicity, and a decreased propensity to apoptosis in response to IL‐15.
Our findings suggest that IL‐15 plays a crucial role in the generation of epithelial damage in active CD. Its promotion of IEL survival in CD may predispose to the emergence of T cell clonal proliferations. Blocking IL‐15, by suppressing uncontrolled IEL activation and survival, has the potential to provide new therapeutic tools to prevent tissue damage and lymphomagenesis in CD.
apoptosis; coeliac disease; cytotoxicity; enterocyte; interleukin 15; intraepithelial lymphocyte; T cell lymphoma
Acid secretion is intimately associated with most upper gastrointestinal diseases. Helicobacter pylori infection is a major environmental factor modifying acid secretion.
To study the association between the pattern of H pylori gastritis and gastric secretory function in a large number of subjects without specific upper gastrointestinal disease.
Methods and materials
Maximal acid output (MAO) was measured in 255 patients with dyspepsia showing normal endoscopy. Activity and severity of gastritis, atrophy and H pylori infection were assessed in body and antral biopsies. The correlations of histological parameters as well as age, sex, height, weight, smoking, serum gastrin, pepsinogen I and II, and their ratio with MAO were determined. Multiple linear regression was used to show the best possible predictors of MAO.
Negative relationships: Body atrophy and body‐combined (active and chronic) inflammatory scores showed a potent inverse correlation with MAO (correlation coefficients (CC) 0.59 and 0.50, respectively). Body:antral chronic gastritis ratio and body:antral combined inflammation ratio (both with CC = 0.49) and age (CC = 0.44) were also inversely correlated with MAO. Intestinal metaplasia at both antral and body sites had negative relationships with acid output with CC = 0.23 and 0.20, respectively. Positive relationships: Serum pepsinogen I, body H pylori density:combined inflammation ratio and pepsinogen I:II ratio with CC of 0.38, 0.38 and 0.30, respectively, correlated with MAO. The H pylori density: combined inflammation of both antrum and body positively correlated with MAO (CC = 0.29 and 0.38, respectively). Male sex and patient height also positively correlated with acid output. Modelling showed that body combined inflammatory score, body atrophy, age and serum pepsinogen I are independent predictors of acid output (R2 = 0.62).
Combination of body gastritis, body atrophy, age and serum pepsinogen I can be used as predictors of acid‐secretory state in populations infected with H pylori.
An accurate morphometric method is described for quantifying the intraepithelial lymphocytes (IEL), the area of the epithelium, and the volume of the lamina propria in jejunal mucosa of coeliac patients. All measurements are related to a unit-length of muscularis mucosa which is unaltered by the disease process. The results show a significant decrease in the epithelial surface area and an increase in the volume of the lamina propria in coeliac jejunal mucosa compared with normal levels, even after treatment. The number of IEL is the same as normal before or after treatment. Other workers have shown an apparent increase in IEL in untreated disease which returns to normal levels after therapy. This discordance is explained and the importance of accurate quantitative methodology is stressed.
Using immunohistochemical staining, we examined the presence of secretory component (SC) on epithelial cells in gastric and duodenal biopsy specimens collected from Helicobacter pylori-infected individuals and healthy controls. Gastric epithelial cells from healthy volunteers expressed low, but detectable, levels of SC. In contrast, significantly higher level of expression of SC (P < 0.001) was observed on epithelial cells in the antra of H. pylori-infected individuals. The antral SC expression correlated with staining for gamma interferon of intraepithelial and lamina propria lymphocytes (rs = 0.76 and 0.69, respectively, P < 0.001) and correlated weakly with production of tumor necrosis factor alpha (rs = 0.43, P < 0.05), but it did not correlate at all with interleukin-4 production.
Cholera toxin (CT), besides causing intestinal hypersecretion after intragastric administration or during cholera infection, affects a multitude of regulatory mechanisms within the gut mucosal network, including T cells. By use of microarray screening, real-time PCR, and immunohistochemistry, we demonstrate here a rapid depletion of jejunal CD8+ intraepithelial lymphocytes (IEL) in rats after intragastric CT challenge. This depletion may depend on CT-induced migration of IEL, since it was associated with a progressive decrease of CD8+ cells in the epithelium and a contemporary transient increase of such cells, preferentially at the base of the villi, in the lamina propria. A significant decrease in the total number of villous CD8+ cells at 6 and 18 h after CT challenge was detected; this possibly reflects an efflux from the jejunal mucosa. The kinetics of the CD8+ IEL demonstrate the return to normal intraepithelial position at original numbers already 72 h after the single CT dose. The induced migration seems to be dependent on the enzymatic A-subunit of CT, since challenge with neither sorbitol nor CT B-subunit did mimic the effects of CT on CD8+ IEL. Furthermore, a decrease in the level of both RANTES transcript and protein was detected, most likely as a consequence of the CT-induced migration of CD8+ IEL. These results point to a complex interaction between CT, epithelial cells, and IEL, resulting in a disturbance of the gut homeostasis, which might have relevance for the strong immunomodulatory effects of intragastrically administered CT.
Helicobacter pylori infection has been linked to hypergastrinemia and either decreased or normal G-cell content in the antral mucosa. To clarify this controversial issue, we quantitatively determined antral G-cell content on the same biopsy specimens with three different methods and examined whether these methods are intercorrelated and the relation of these methods to plasma gastrin concentrations, demography, the occurrence of H. pylori infection and chronic gastritis. Gastric antral mucosal biopsy sections from 273 adults (188 with and 85 without H pylori infection) from a general population sample were examined immunohistochemically for G-cells using cell counting, stereology (point counting) and computerized image analysis. Gastritis was scored according to the updated Sydney system. Basal plasma gastrin concentrations were measured by radioimmunoassay. The three methods for G-cell quantification were poorly correlated and the results showed no correlation with basal plasma gastrin concentrations. The antral G-cell density and scores for H. pylori colonization were positively related to age. Neither the scores for chronic inflammation, nor the scores for inflammatory activity, atrophy or intestinal metaplasia were consistently related to the antral G-cell content. In conclusion, the results of three techniques for G-cell quantification in the gastric antral mucosa were poorly intercorrelated and none of the methods correlated with plasma gastrin concentrations. Age and scores for H pylori colonization seem to be determinants of the G-cell density. That common morphometric techniques correlate poorly is of utmost importance to bear in mind when quantitative morphological studies are planned, compared or interpreted.
Gastrin; cell counting; computerized image analysis; gastritis; inflammation; morphometry; point counting; stereology; stomach
pylori urease is a major target for immune responses among
various bacterial components in H pylori infected patients.
Aims—To analyse the relation
between systemic and local humoral immune responses to
H pylori urease and grades of chronic gastritis.
Patients—Seventy five patients with
chronic gastritis associated with H pylori
infection were classified into three groups (grade I, superficial
gastritis; II, atrophic gastritis, quiescent; or III, atrophic
pylori urease specific antibodies in the serum, gastric juice,
and biopsy specimens were determined by ELISA or western blotting
analysis. The sites for H pylori urease and its specific antibody producing B lymphocytes were confirmed by immunohistochemical analysis.
Results—In the sera of patients
with grade I gastritis, weak IgG but relatively strong IgA responses to
H pylori urease were observed; dominant
strong IgG responses were detected in grade II gastritis. In grade III
gastritis, significant IgG and IgA responses were obtained. A similar
pattern of IgA and IgG responses was detected in gastric juice and
tissue. H pylori urease specific, antibody
producing B cells were not found in the gastric mucosa of patients with
grade I gastritis despite the presence of such B cells in the duodenal
bulb. Specific B cells were observed in the gastric mucosa of patients
with grade II and III gastritis with atrophy.
H pylori urease, together with localisation
of its specific antibody producing B cells, are useful for serological
testing and histopathological analysis for determining the stage of
chronic gastritis and studying the pathogenesis of H pylori infection.
Helicobacter pylori; urease; chronic gastritis; B lymphocytes; antibody production; local