Superficial gastritis and Campylobacter pylori in dyspeptic patients--a quantitative study using computer-linked image analysis

Helicobacter infections with rare bacteria or minimal gastritis: Expecting the unexpected

BACKGROUND

The routine use of special stains for detection of Helicobacter remains controversial.

AIMS

To determine the frequency of histologically atypical Helicobacter infection.

METHODS

All gastric biopsies received at a large pathology reference laboratory over a 6-month period were stained for Helicobacter, and the histologic and clinicopathologic parameters evaluated.

RESULTS

Amongst 7663 Helicobacter-positive biopsies, 823 (10.7%) did not show typical chronic active gastritis with numerous Helicobacter organisms, and were therefore considered histologically atypical. Rare Helicobacter pylori organisms accounted for 58.0% of all atypical infections; the next most common atypical Helicobacter infection was that with minimal or no gastric inflammation (23.3% of atypical infections). Patients in these groups did not differ demographically from those with other forms of atypical or typical Helicobacter infection, although a small subgroup (6%) was more likely to have had a previously treated infection.

CONCLUSIONS

In many of these atypical infections, Helicobacter would not have been suspected based on the histologic findings alone, and would have been missed without routine special stains. Performing a sensitive stain could prevent additional testing and allow prompt treatment of the affected patients, thus substantially reducing the risk for peptic ulcer and gastric cancer and preventing the transmission of the infection to family members.

Gastric biopsies: the gap between evidence-based medicine and daily practice in the management of gastric Helicobacter pylori infection

BACKGROUND

Many consider histology to be the gold standard for Helicobacter pylori detection. Because the number and distribution of H pylori organisms vary, particularly in patients taking proton pump inhibitors (PPIs), the American Gastroenterological Association recommends discontinuing PPIs two weeks before endoscopy, and taking biopsies from both the body and antrum.

OBJECTIVE

To assess the influence of clinical practice on the histopathological detection of H pylori infection.

METHODS

Electronic patient records were evaluated for the sites of gastric sampling and PPI use at endoscopy. One hundred fifty cases with biopsies taken from both antrum and body were randomly selected for pathological re-review with special stains. The gastric regions sampled, H pylori distribution and influence of clinical factors on pathological interpretation were assessed.

RESULTS

Between 2005 and 2010, 10,268 biopsies were taken to detect H pylori. Only one region was sampled in 60% of patients (antrum 47%, body 13%). Re-review of biopsies taken from both antrum and body indicated that the correct regions were sampled in only 85 (57%) patients. Of these, 54 were H pylori positive and 96 were H pylori negative. H pylori was present in the antrum in only 15% of the patients and body only in 21%. Of 96 H pylori-negative patients, two were reinterpreted as positive. Forty-seven per cent of patients were taking PPIs at endoscopy, contributing to both false-negative and false-positive diagnoses.

CONCLUSION

Despite national and international guidelines for managing H pylori infection, the American Gastroenterological Association guidelines are infrequently adhered to, with PPIs frequently contributing to false diagnosis; sampling one region only increases the likelihood of missing active infection by at least 15%.

Intestinal immune activation in presumed post-infectious functional dyspepsia

Functional dyspepsia (FD) symptoms may develop after an acute gastroenteritis. In post-infectious (PI) irritable bowel syndrome, persisting low-grade colonic inflammation and increased enterochromaffine cells (EC) counts have been reported. The aim was to compare signs of inflammation and EC hyperplasia on duodenal biopsies in presumed PI-FD and unspecified-onset (U-)FD. Duodenal biopsies were obtained in 12 U-FD and 12 PI-FD (on average 13 months after the acute event) patients. The presence of intra-epithelial, intravillar, and the number of CD3, CD4, CD8 and CD68+ cells per crypts, and the mean number of Chromogranine A (CA) positive cells per villus were compared. We also measured gastric emptying and assessed proximal stomach function with a barostat. Data are shown as mean +/- SEM. Focal aggregates of T cells and focal CD8+ aggregates, were found in PI-FD but not in U-FD patients (respectively 5/12 vs 0/12, P = 0.02 and 5/9 vs 0/11, P < 0.01). In patients with focal aggregates, gastric emptying was delayed (189 +/- 37 min vs 98 +/- 11 min, P = 0.002). The number of CD4+ cells per crypt (0.52 +/- 1.6 vs 1.22 +/- 2.18, P = 0.04), and the number of intravillar CD4+ cells (0.5 +/- 0.2 vs 2.7 +/- 0.7, P = 0.01) were reduced, while the number of CD68+ cells per crypt was increased (0.64 +/- 0.13 vs 0.40 +/- 0.05, P = 0.03) in PI-FD. The number of EC and CA were comparable. PI-FD is associated with persisting focal T-cell aggregates, decreased CD4+ cells and increased macrophage counts surrounding the crypts. This may indicate impaired ability of the immune system to terminate the inflammatory response after acute insult.

Review article: Helicobacter pylori and nonulcer dyspepsia

Although up to 50% of patients diagnosed with nonulcer dyspepsia (NUD) have Helicobacter pylori infection and underlying chronic gastritis, it remains controversial whether any causal relationship exists. The results of worldwide epidemiological studies have been unconvincing. No clear-cut link has been documented between H. pylori and any specific symptom profile or pathophysiological mechanism in NUD. In the randomized controlled trials, methodological weaknesses may explain in part the conflicting results, but even in the well-conducted trials controversy persists. Although meta-analyses have attempted to resolve the issue, inherent methodological difficulties with meta-analysis remain a problem. Moreover, even the methodologically sound meta-analyses have reported conflicting results. In addition, predictors of treatment response remain obscure, and there continue to be theoretical concerns about the treatment of H. pylori infection in all patients with NUD. Hence, the management of these patients is challenging, but eradication of H. pylori infection may be beneficial in a small subgroup of cases with NUD that cannot be identified before treatment.

Acute inflammation of the proliferative zone of gastric mucosa in Helicobacter pylori gastritis

The neutrophilic infiltration has been regarded to represent the activity of Helicobacter pylori gastritis. It may involve the epithelium and/or lamina propria. The incidence and degree of the two types of infiltration do not correlate with each other frequently. We correlated the two types of neutrophilic infiltration with H. pylori infection and other pathologic parameters respectively in 300 randomly selected gastric biopsies as well as serial biopsies from a separate group of 95 patients who were treated for H. pylori infection. The "random biopsies" had chronic gastritis of various degrees, and the organisms were identified in 239 cases (79.7%); in the "treated group," the organisms disappeared completely in 62 cases (65.3%). Characteristically, the intraepithelial neutrophilic infiltration was predominantly localized to the proliferative zone of the gastric mucosa (zone 2) where the density of H. pylori was considerably lower than the surface epithelium. In the "random biopsies," both acute epithelial and interstitial neutrophilic infiltration correlated significantly (p < 0.01) with the H. pylori infection. In the "treated group," however, only acute epithelial inflammation correlated significantly (p < 0.01) with the eradication of infection while acute interstitial inflammation did not. Acute epithelial inflammation was no less frequently present in advanced chronic gastritis than in early chronic gastritis. Acute epithelial inflammation of the proliferative zone is a characteristic pathologic finding of H. pylori gastritis, and appears to be directly associated with the pathogenesis of H. pylori gastritis and its progression.

Helicobacter pylori and functional dyspepsia: a real causal link?

This chapter reviews the evidence for a link between functional dyspepsia and Helicobacter pylori infection from three angles. In the section on pathophysiology, we evaluate how H. pylori could theoretically produce dyspeptic symptoms: many mechanisms can be proposed. In the discussion on epidemiology, we evaluate possible associations between the occurrence of symptoms and infection. Here, many studies claiming a coincidence or chronological sequence of infection and symptoms are criticized because of their poor design. In the section on the improvement of functional dyspepsia by the treatment of H. pylori infection, the conclusion is reached that if such an effect occurs at all--which is unlikely--it is very weak. The controversy on the link between H. pylori infection and functional dyspepsia is presently ongoing. Some authors are still trying to save an elegant concept that once looked so plausible but now has the facts against it.

Helicobacter pylori

Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection.

Helicobacter pylori

Helicobacter pylori is a gram-negative bacterium which causes chronic gastritis and plays important roles in peptic ulcer disease, gastric carcinoma, and gastric lymphoma. H. pylori has been found in the stomachs of humans in all parts of the world. In developing countries, 70 to 90% of the population carries H. pylori. In developed countries, the prevalence of infection is lower. There appears to be no substantial reservoir of H. pylori aside from the human stomach. Transmission can occur by iatrogenic, fecal-oral, and oral-oral routes. H. pylori is able to colonize and persist in a unique biological niche within the gastric lumen. All fresh isolates of H. pylori express significant urease activity, which appears essential to the survival and pathogenesis of the bacterium. A variety of tests to diagnose H. pylori infection are now available. Histological examination of gastric tissue, culture, rapid urease testing, DNA probes, and PCR analysis, when used to test gastric tissue, all require endoscopy. In contrast, breath tests, serology, gastric juice PCR, and urinary excretion of [15N]ammonia are noninvasive tests that do not require endoscopy. In this review, we highlight advances in the detection of the presence of the organism and methods of differentiating among types of H. pylori, and we provide a background for appropriate chemotherapy of the infection.

Helicobacter pylori infection and dyspepsia

It has proved remarkably difficult to confirm or refute an association between Helicobacter pylori-induced gastritis and non-ulcer dyspepsia for several reasons. Dyspepsia has not been defined adequately and current definitions include a variety of symptoms that probably reflect a number of underlying pathophysiological processes. Dyspepsia is a symptom complex, rather than a specific disease entity, and cannot be easily identified. There are probably many causes of dyspepsia, and if H. pylori does cause symptoms, it may produce different symptoms in different people. However, little is known about variations in host susceptibility and H. pylori virulence, or their potential effect on symptomatology. In addition, the mechanisms responsible for dyspeptic symptoms are unknown, regardless of whether or not there is concomitant H. pylori-induced inflammation. A possible aetiological role for H. pylori in dyspepsia has been sought in three major types of study. Epidemiology studies have suggested that H. pylori is not a major cause of non-ulcer dyspepsia. However, both dyspepsia and H. pylori are common, and the studies cannot account for many of the variables detailed above. Pathophysiological studies have commonly reported a variety of motor and sensory 'abnormalities' in association with H. pylori, but none has been confirmed or reproduced. In eradication studies, there is continuing debate as to whether dyspeptic symptoms diminish with treatment. This is partly because of the high placebo-response rate and partly because many treatment regimens have not cured the infection. Suppression of bacterial growth may not affect symptoms significantly, if they are due to mucosal inflammation, and symptom resolution may take many weeks or months following cure of H. pylori and the associated gastritis. Recent findings have shown that symptom reduction is more evident 1 year after eradication of H. pylori than after 4 weeks. There is a continuing and urgent need for well-designed studies to assess the long-term effect of H. pylori and its cure on both gastrointestinal function and dyspeptic symptoms.

Difference in expression of Helicobacter pylori gastritis in antrum and body

Seven hundred seventy biopsy specimens obtained from 10 different sites in stomachs of 77 patients were examined for the presence of active chronic gastritis (ACG) and Helicobacter pylori to investigate the characteristics of gastritis in the antrum and body. Forty-eight patients with ACG at one or more sites were all H. pylori positive. H. pylori was not found in 20 patients who had chronic gastritis with no activity or in 9 patients who had histologically normal mucosa. In patients with ACG in at least one biopsy site, a strong positive topographic association between H. pylori colonization and ACG was seen in the Warthin-Starry stain. The frequency of H. pylori colonization was similar in the antrum and body. However, the incidence of ACG declined significantly proximal to the borderline between the antrum and body (P less than 0.001). The average grade of gastritis at the individual biopsy sites was distributed evenly throughout the antrum but decreased markedly in the body (P less than 0.0001). In the same manner, the average grade of H. pylori colonization decreased in the body (P less than 0.0027). The grade of H. pylori colonization in the individual biopsy specimens was closely related to the grade of gastritis (r = 0.51); also, the grade of neutrophil infiltration was related to the grade of gastritis (r = 0.79). A good correlation existed between the grade of H. pylori colonization and the grade of neutrophil infiltration (r = 0.70). The results of this study show a different expression of H. pylori gastritis in the antrum and body, which is the main subtype of chronic type B gastritis. The close topographic and graded association between the presence of H. pylori and the activity and grade of gastritis lend further support to the major pathogenic role of H. pylori in active chronic gastritis. The different expression of gastritis in antrum and body is suggested to be increased reactivity of the antral mucosa to the infection, possibly on the basis of an enhanced immunologic response to H. pylori in this region.

Epithelial damage by Helicobacter pylori in gastric ulcers

On review of 136 consecutive biopsies of benign gastric ulcer, Helicobacter pylori was detected in 78 cases (57.3%). The gastric epithelium colonized by Helicobacter pylori showed a characteristic constellation of changes, including loss of apical mucous portion of individual cells, drop-out of epithelial cells, epithelial pits, erosions and cellular tufts, indicative of cellular injury and regeneration. Among the 58 Helicobacter-negative cases, similar changes were not observed in the ulcer edges, except for two cases which exhibited some cellular tufts. Thus, the topographic association of Helicobacter pylori with epithelial damage in the gastric ulcer edges in more than half of the cases suggests that this organism probably plays an aetiological role in ulcerogenesis, at least in these cases. Furthermore, the epithelial changes are so distinctive that they can serve as a helpful histological indicator for the presence of Helicobacter pylori in gastric biopsies.

Grading of superficial antral gastritis: comparison of cell-counting and photographic-based methods

A cell-counting technique and a photographic-based scoring system for assessing inflammatory cell infiltration were compared for agreement in 275 endoscopic gastric antral biopsies from 55 dyspeptic patients. Each biopsy was independently scored 0-5 for polymorphs and mononuclear cells using both methods, and a mean score was derived for each patient. There was a highly significant correlation between the mean patient scores obtained using each method (P less than 0.001). Agreement statistics showed that the mean score difference (cell-counting minus photographic score) was negative for polymorphonuclear and mononuclear cells, indicating that the photographic method yielded higher mean patient scores. Scatterplots of difference versus mean by the two methods showed that only 3.6 per cent of scores fell outside +/- 2 SD of the mean difference. The use of standard photomicrographs to grade superficial antral gastritis therefore provides accurate results, comparable to those obtained by cell counting, yet is a faster and much cheaper technique.