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Summary

  1. Top of page
  2. Summary
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Background

Among Western populations, the declining incidence of Helicobacter pylori infection coincides with a growing clinical impact of autoimmune gastritis.

Aims

To describe the histological phenotype of autoimmune gastritis, also to test the prognostic impact of OLGA staging in the autoimmune setting.

Methods

A single-institutional series (spanning the years 2003–2011) of 562 consecutive patients (M:F ratio: 1:3.7; mean age = 57.6 ± 14.4 years) with serologically confirmed autoimmune gastritis underwent histology review and OLGA staging.

Results

Helicobacter pylori infection was ascertained histologically in 44/562 cases (7.8%). Forty six biopsy sets (8.2%) featured OLGA stages III–IV; they included all four cases of incidental epithelial neoplasia (three intraepithelial and one invasive; three of these four cases had concomitant H. pylori infection). There were 230 (40.9%) and 139 (24.7%) cases, respectively, of linear and micro-nodular enterochromaffin-like cell hyperplasia; 19 (3.4%) type I carcinoids were detected. The series included 116 patients who underwent repeated endoscopy/biopsy sampling (mean time elapsing between the two procedures = 54 months; range 24–108). Paired histology showed a significant (= 0.009) trend towards a stage progression [the stage increased in 25/116 cases (22%); it remained unchanged in 87/116 cases (75%)].

Conclusions

In autoimmune gastritis, the cancer risk is restricted to high-risk gastritis stages (III–IV), and is associated mainly with concomitant H. pylori infection. OLGA staging consistently depicts the time-dependent organic progression of the autoimmune disease and provides key information for secondary gastric cancer prevention strategies.


Introduction

  1. Top of page
  2. Summary
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

The declining incidence of Helicobacter pylori-gastritis parallels a growing clinical focus on autoimmune gastritis (AG).[1, 2] Autoimmune gastritis is due to an aggression targeting the parietal cells and affects the corpus-fundus mucosa; it is associated with serum anti-parietal cell and anti-intrinsic factor antibodies.[1, 3] Clinical signs of AG include hypo/achlorhydria, hypergastrinaemia, low pepsinogen I/pepsinogen II ratio and vitamin B12-deficient anaemia.[1, 4] Long-standing hypo/achlorhydria triggers enterochromaffin-like (ECL) cell hyperplasia, which may further progress to endocrine tumours (type I carcinoid).[5-9]

The histology of AG typically features a corpus-restricted (chronic) inflammation that may develop into oxyntic mucosa atrophy. The atrophic changes include the loss of glandular units (resulting in fibrosis of the lamina propria), and/or the metaplastic replacement of native oxyntic glands. Metaplasia includes two different phenotypes: pseudo-pyloric metaplasia [i.e. spasmolytic polypeptide-expressing metaplasia (SPEM)] and/or intestinal metaplasia (IM).[2] Due to these atrophic changes, AG is listed among the gastric precancerous conditions.[2, 6, 10-13]

A staging system for reporting gastritis histology (OLGA staging) has recently been proposed: by scoring atrophy histologically in both oxyntic and antral/angular biopsy samples, the staging frame (stages 0–IV) ranks gastritis according to its GC risk.[14, 15] In different epidemiological settings (mainly addressing H. pylori-related gastritis), OLGA stages III–IV consistently feature a high GC risk,[2, 14, 16] but the clinical value of gastritis staging in AG has yet to be explored.

This retrospective study assessed the gastric mucosa histology (including OLGA staging) in a series of 562 consecutive serologically proved AG patients. The progression of the disease over time was explored in a subgroup of 116 patients for whom repeated endoscopy (with biopsy samples) was available at least 24 months after the index endoscopy.

Patients and Methods

  1. Top of page
  2. Summary
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Patients

This study concerns a consecutive series of patients with serologically proven AG (see inclusion criteria). The cases were retrieved from the electronic archives of the Department of Pathology at Padua University (January 2003–December 2011), drawing no distinction between initial and follow-up endoscopies. All patients were Caucasian and native of the Veneto Region and they underwent endoscopy at Padua University Hospital. The institute's ethical regulations on research conducted on human tissues were followed.

Inclusion criteria were as follows:

  1. A clinical syndrome consistent with AG and a conclusive diagnosis established on serology. In all cases, at least one serological test documented the presence of parietal cell and intrinsic factor autoantibodies (Autozyme IFAb; Cambridge Life Sciences, Ely, UK).
  2. The availability of a standard set of gastric biopsy samples, i.e. two from the antral mucosa, one from the mucosa of the incisura angularis, and two from the anterior and posterior walls of the oxyntic mucosa. Additional specimens could be available, obtained from any incidental focal lesions (information on the topography of the biopsy samples was obtained from the endoscopy report).

Exclusion criteria were age under 18 years and a clinical history of gastrointestinal surgery (oesophageal or gastric surgery, oesophagogastric endomucosal resection, oesophagogastric submucosal dissection). In total, 562 patients met the enrolment criteria; when patients had undergone multiple endoscopies, only the index endoscopy/biopsy set was considered.

Among patients (i.e. 205) who underwent more than one endoscopy, in 116 cases, the time elapsing between the first (T1) and the last endoscopy (T2) was 24 months (or longer). In these cases, the two biopsy sets were considered with a view to comparing the gastritis phenotype/stage seen at T1 vs. T2.

Histology

Original slides or serial sections (4–6 μm thick) obtained from archival paraffin-embedded tissue samples (H&E, Alcian-PAS, and Giemsa for H. pylori) underwent histological review. In doubtful cases, pseudo-pyloric metaplasia (PPM) was confirmed by pepsinogen I immuno-staining (Biohit Oyj, Helsinki, Finland; immunostain protocol applied as previously described[17]; Figure 1).

image

Figure 1. Representative images of the series considered. (a) An example of metaplastic changes occurring in the oxyntic mucosa (H&E). Note the coexisting intestinal and pseudo-pyloric metaplastic lesions. The oxyntic commitment was confirmed by applying anti-pepsinogen I antibody (b). Representative examples of linear (c) and combined linear/micronodular (d) hyperplastic lesions of ECL cells (anti-chromogranin stain). A case of gastric type I carcinoid tumour (e; H&E); the neuroendocrine nature of the lesion is confirmed by anti-NSE positivity (f). Original magnifications 20× and 40×.

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Two trained GI pathologists (MF, MP), blinded to any of the patients’ endoscopic or clinical information, jointly assessed all the histology specimens and reached a consensus on the atrophy scores. For OLGA staging purposes, atrophy was assessed in terms of the loss of appropriate glands (i.e. IM in antral and/or oxyntic biopsy samples; PPM in oxyntic biopsy samples; Figure 1).[18, 19] Glandular atrophy was scored according to the recommendations of the OLGA staging tutorial.[2, 15] The inter-observer consistency in OLGA staging was tested by means of k statistics in a randomly selected series of 100 cases and was ranked as ‘excellent’ (k coefficient = 0.75).

Incidental neoplastic lesions [intraepithelial (IEN) or invasive] were assessed histologically according to internationally established criteria.[20-22] Two categories were considered within the spectrum of gastric IEN (synonymous for dysplasia), i.e. low-grade IEN, and high-grade IEN. Gastric adenocarcinoma was diagnosed where neoplastic epithelia infiltrated the lamina propria.

Within the spectrum of neuroendocrine lesions, ECL-cell hyperplasia was assessed according to internationally validated criteria, distinguishing linear vs. micronodular hyperplasia (which was scored separately) (Figure 1). Well differentiated endocrine tumours (i.e. type I carcinoids) were assessed histologically according to the current international criteria (Figure 1).[23] The neuroendocrine commitment of both ECL hyperplasia and carcinoids was always supported by appropriate immunostaining (neuron-specific enolase; clone BBS/NC/VI-H14; DAKO, Milan, Italy; chromogranin A; clone DAK-A3; DAKO).[24]

Statistical analysis

The strength of the association between the OLGA stage and the patient's demographic and pathological features was calculated by applying Fisher's exact test (F), the Mann–Whitney test (MW), Student's t-test (t), the modified Kruskal–Wallis nonparametric test for trend (KW), and the Wilcoxon nonparametric test for matched pairs (W), as appropriate. The inter-observer consistency in classifying biopsy sets according to the OLGA staging system was checked in a series of 100 randomly selected biopsy sets and calculated as the overall proportion of agreement (the number of total paired observations in which the same result was obtained), and tested using Fleiss's kappa statistic.[25] Significance was inferred at a P-value of less than 0.05. The statistical analysis was performed using the stata 8.0 software (Stata Corporation, College Station, TX, USA).

Results

  1. Top of page
  2. Summary
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Overall clinico-pathological profile

In all, 562 biopsy sets obtained from 562 patients were considered (Table 1; Figure 2). The male:female (M:F) ratio was 119/443 (M:F = 1:3.7); the mean age was 56.1 years (s.d. = 14.5, range = 18.5–89.9). Males mean age was significantly higher (M = 59.8 years; range = 18.5–87.2; F = 55.8 years; range = 19.3–89.9; t,= 0.012).

image

Figure 2. OLGA stage distribution in the series considered.

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Table 1. Demographic and clinico-pathological characteristics of the patients considered
 TotalOLGA stage
0IIIIIIIV
  1. ECL, enterochromaffin-like cell; ECL linear, ECL linear hyperplasia; ECL MN, ECL micronodular hyperplasia; GC, gastric cancer; Hp+ve status, Helicobacter pylori detected on histology; IEN, intra-epithelial neoplasia (i.e. dysplasia); IM+ve, intestinal metaplasia positive (including both antral and oxyntic mucosa biopsy samples); s.d., standard deviation.

  2. Values within parenthesis are expressed in percentages.

Patients number56252 (9.3)90 (16.0)374 (66.5)37 (6.6)9 (1.6)
Gender (M/F)119/4434/4815/7591/2837/302/7
Age (mean ± s.d.)56.1 ± 14.548.6 ± 14.054.1 ± 12.956.9 ± 13.760.8 ± 13.863.9 ± 12.3
Hp+ve status44 (7.8)11 (21.2)8 (8.8)22 (5.9)2 (5.4)1 (11.1)
IM+ve391 (69.6)0 (0.0)61 (67.7)286 (76.5)36 (97.3)8 (88.9)
ECL linear230 (40.9)1 (1.9)19 (21.1)178 (47.6)25 (67.6)7 (77.8)
ECL MN139 (24.7)1 (1.9)5 (5.6)112 (29.9)16 (43.2)5 (55.6)
Carcinoids19 (3.4)0 (0.0)0 (0.0)17 (4.5)1 (2.7)1 (11.1)
IEN/GC4 (0.7)0 (0.0)0 (0.0)0 (0.0)3 (8.1)1 (11.1)

Fifty-two of the 562 patients (9.3%) featured no atrophic changes (i.e. OLGA stage 0); the mean age of these patients was significantly lower than that of the patients featuring atrophic changes (Stages I/II/III/IV; t;< 0.001). The patients’ mean age increased significantly by stage (from stage 0–IV; KW; < 0.001). Among atrophic gastritis (stages I–IV), lower stages prevailed significantly (stages I–II = 464; 82.6% vs. stages III–IV = 46; 8.2%).

Helicobacter pylori infection was identified histologically in 44/562 biopsy sets (7.8%); overall, the prevalence of the infection was higher among lower OLGA stages (stages 0, I and II; MW: < 0.001). The highest prevalence of H. pylori infection was found among stage 0 patients (11/52; 21.2%; Table 1).

Metaplastic changes (intestinal and pseudopyloric metaplasia)

Pseudo-pyloric metaplasia (restricted to the oxyntic biopsy specimens by definition) was observed in 479/562 (85.2%) cases. Irrespective of its antral or corpus location, IM was observed in 391/562 (69.6%) cases. Mucosa intestinalisation was restricted only to the oxyntic specimens in 327/391 (83.6%) cases, whereas no cases of antrum-restricted IM were seen. Among the 65 biopsy sets featuring antral atrophy, H. pylori infection was found on histology in 7 (10.8%).

Neuroendocrine lesions

In biopsy samples obtained from oxyntic mucosa, linear and micronodular ECL-cells hyperplasia were seen in 230/562 (40.9%) and 139/562 (24.7%) cases respectively. All micronodular ECL-cell hyperplasia coexisted with linear ECL-cell hyperplasia. The prevalence of ECL-cell hyperplastic lesions (linear and micronodular) increased significantly by OLGA stage (KW: < 0.001; both).

Nineteen incidental type I carcinoids (tumour grade: G1 = 17, G2 = 2)[26] were observed. The mean age of carcinoid patients (M:F ratio was 8/11) was higher than that of non carcinoid patients (carcinoid patients: 59.3 years [s.d. = 11.3; range = 41.0–82.5] vs. mean age of non carcinoid patients: 56.0 years [s.d. = 14.5; range = 18.5–89.9]). All carcinoids coexisted with ECL linear/micronodular hyperplasia and corpus intestinalisation (17 of 19 [89.5%] carcinoids coexisted with score 3 corpus atrophy).

Epithelial neoplasia

Four (0.7%) epithelial neoplastic lesions (IEN or invasive carcinoma) were encountered, i.e. two cases of low-grade IEN, one of high-grade IEN and one of intestinal-type adenocarcinoma. They were all associated with OLGA stages III-IV (significant association with high-risk OLGA stages; MW; < 0.001) (Table 1; Figure 2). Two of the three cases of IEN were associated with H. pylori infection. The only case of invasive (intestinal-type) gastric cancer (pTNM stage: pT1bN0M0) was associated with stage III gastritis; it was distally located, and featured H. pylori infection (confirmed by serology).

Patients with repeated endoscopy: initial vs. final histology

In 116 of the 562 patients (M:F = 0.25:1), an adjunctive endoscopy/biopsy was performed 24 (or more) months (T2) after the index (T1) endoscopy (mean time elapsing between T1 and T2 = 54 months; range = 24–108 months) (Table 2; Figures 3 and 4). At the initial endoscopy, the patients were a mean 53.5 years old (s.d. = 12.9; range = 25.3–78.7), and H. pylori infection was identified histologically in 10/116 (8.6%) cases; between T1 and T2, H. pylori was eradicated in 9 of 10 cases.

image

Figure 3. Corpus scoring distribution at the initial (T1) and follow-up (T2) biopsy in the subgroup of 116 patients with repeat endoscopies after ≥24 months.

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image

Figure 4. OLGA stage at the first (T1) and last (T2) endoscopy in the subgroup of 116 patients with a follow-up ≥24 months. The squares (diagonal) indicate patients who had the same stage at T1 and T2; above the diagonal are the cases whose stage at T2 was higher than that assessed at the initial biopsy (T1); below the diagonal are the cases whose stage at the follow-up T2 was lower than that assessed at the initial biopsy (T1).

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Table 2. Demographic and clinico-pathological characteristics at index (T1) and final (T2) examination (mean follow-up 54 months; range = 24–108; male/female = 23/93)
VariableT1T2Statistics
  1. ECL, enterochromaffin-like cell; ECL linear, ECL linear hyperplasia; ECL MN, ECL micronodular hyperplasia; Hp, Helicobacter pylori; IM+ve, intestinal metaplasia positive; s.d., standard deviation.

  2. Values within parenthesis are expressed in percentages.

Mean age ± s.d.53.5 ± 12.958.0 ± 13.3
Hp statusPositive10 (8.6)1 (0.9)
 Negative106 (91.4)106 (91.4) 
 Eradicated0 (0.0)9 (7.8) 
Intestinal metaplasia80 (69.0)94 (81.0)W: = 0.001
ECL linear hyperplasia42 (36.2)71 (61.2)W: < 0.001
ECL micronodular hyperplasia18 (15.5)42 (36.2)W: < 0.001
Type I carcinoids0 (0.0)2 (1.7) 
OLGA stage06 (5.2)6 (5.2)F: = 0.009
 I25 (21.6)8 (6.9) 
 II83 (71.6)93 (80.2) 
 III2 (1.7)9 (7.8) 
 IV0 (0.0)0 (0.0)

Figure 3 shows the oxyntic atrophy score values for this subset of patients (corpus atrophy score values at T1 vs. T2): on the whole, the atrophy scores increased significantly from T1 to T2 (no changes in 57 cases [49.1%]; higher scores at T2 in 46 [39.7%]; lower scores at T2 in 13 cases [11.2%]; F; < 0.001; Figure 3, Table 2).

The gastritis OLGA stage increased significantly from T1 to T2 (with no change in 87 cases [75.0%]; a higher stage at T2 in 25 [21.6%]; and a lower stage at T2 in 4 [3.4%]; F, = 0.009; Figure 4, Table 2). As for H. pylori status, one of the nine eradicated cases experienced a stage regression (from II to I); the only non-eradicated H. pylori-positive patient progressed from stage I to stage II.

The prevalence of ECL hyperplasia (both linear and micronodular) significantly increased from T1 to T2 (W: < 0.001; Table 2), and two new cases of type I carcinoid were detected among the T2 endoscopies. No epithelial neoplastic lesions were observed.

Discussion

  1. Top of page
  2. Summary
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

The prevalence of gastritis is increasing considerably in Western countries,[1, 2] but there is still a paucity of information available on its pathobiology and natural history.

With a view to exploring the AG phenotype, this retrospective single-institution study considered a consecutive series of 562 AG biopsy sets, more than 90% of which featured gastric mucosa atrophy: in biopsy samples obtained from oxyntic mucosa, the atrophic changes featured loss of native oxyntic glands replaced by pseudopyloric (479/562 [85.2%]) or intestinalised (327/562 [58.2%]) glandular units.[2]

Helicobacter pylori infection coexisted in 44 (7.8%) of the 562 biopsy sets considered, with a significantly lower prevalence than the one usually seen in the endoscopy population of the geographical region concerned [the prevalence of H. pylori infection in the endoscopy population of the Veneto Region has ranged between 25% and 30% in the last 5 years (unpublished data as obtained from the electronic archive of the Department of Pathology at Padova University Hospital)].

In the setting of H. pylori-gastritis, there is well established evidence of the extent and topography of atrophy (gastritis stage) correlating with the risk of epithelial malignancies.[14, 16, 27] No studies are available on the clinical impact of staging in the AG, however. As in H. pylori-gastritis, so too in our series of AG, low stages largely prevailed (i.e. 0, I and II; 91.8%).[14, 28] All the epithelial neoplastic lesions were clustered in stages III and IV, further supporting the association between OLGA stages III–IV and gastric cancer risk. In the present series of 562 AG patients, the prevalence of incidental neoplasia (be it invasive or IEN) was significantly lower (0.7%) than was documented in a consecutive series of endoscopies performed in 247 H. pylori-positive patients recruited from the same geographical area (1.5%).[14] Taking into account that three of the four neoplastic lesions detected in the present study were in H. pylori-positive patients, our results associate a considerably lower cancer risk with AG than with H. pylori infection.

As for the relationship between gastritis stage and neuroendocrine lesions, the prevalence of ECL hyperplasia phenotypes (linear and micronodular) was significantly higher, the higher the stage of gastritis. Consistently with current knowledge about the natural history of carcinoids,[29] they all coexisted with extensive corpus mucosa atrophy.

Among the 562 patients considered, 116 had a repeat endoscopy/biopsy at least 24 months after the index endoscopy (mean interval between the two procedures: 54 months; range = 24–108): at the latter time point, the progression of oxyntic atrophy resulted in a significantly higher OLGA stage. It should be noted that H. pylori was eradicated between T1 and T2 in 9 of the 10 patients found H. pylori-positive at T1, which virtually rules out any role of H. pylori in this progression. The clinico-pathological worsening of the autoimmune disease at T2 was further supported by the two new-found cases of type I carcinoid at T2 endoscopy.

A gastritis staging system alternative to the OLGA has recently been proposed. This OLGIM system only considers IM as the key lesion to score for staging purposes.[30, 31] By excluding both non metaplastic and pseudopyloric metaplasia from the atrophy score, OLGIM disregards those atrophy phenotypes occurring specifically in AG. Such an assumption could lead specifically to down-staging AG patients who would have been considered at high risk if a global atrophy score had been applied (finally resulting in physicians overlooking patients at high risk of GC).[28] Recent evidence supports the importance of pseudopyloric metaplasia in gastric carcinogenesis (through transdifferentiation from mature chief cells following parietal cell loss).[32, 33] The present results fail to support the precancerous significance of the pseudopyloric transformation of the oxyntic glands, probably due to the limited number of cases considered.

In conclusion, OLGA staging in AG patients can effectively convey unequivocal information on gastritis-associated cancer risk. Additional studies should explore the prognostic relationship between OLGA staging on histology and gastric serology (pepsinogens and gastrin) in AG patients.

Acknowledgements

  1. Top of page
  2. Summary
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References

Declaration of personal interests: We also thank Dr Vincenza Guzzardo, Dr Mariangela Balistreri, Dr Cristiano Lanza and Dr Vanni Lazzarin for their excellent technical support. Anti-pepsinogen I antibodies were kindly provided from Biohit Oyj (Finland). M Fassan is a paid consultant for Menarini Diagnostics s.r.l. for matters of diagnostic testing. Declaration of funding interests: This research was supported by the AIRC grant Veneto Region, 2008; the “Guido Berlucchi” Foundation, and the “Morgagni” Association for Oncological Research (Padua). The funding agencies had no role in the design and performance of the study.

References

  1. Top of page
  2. Summary
  3. Introduction
  4. Patients and Methods
  5. Results
  6. Discussion
  7. Acknowledgements
  8. References