Long-term follow-up of gastric metaplasia after eradication of Helicobacter pylori Yoshihito Urakami*, and Toshiaki Sano** *Department of Gastroenterology, Urakami Gastro Clinic, Tokushima, Japan;and ** Department of Pathology, The University of Tokushima School of Medicine, Tokushima, Japan Abstract: Backgrounds and Aims:There is no commonly accepted view concerning changes in gastric metaplasia after the eradication of Helicobacter pylori. The aim of this study was to evaluate the long-term course of gastric metaplasia after the eradication of this bacterium. Methods:The subjects were 59 patients with duodenal ulcer who were positive for Helicobacter pylori. Forty patients were classified as the eradication group. Gastric metaplasia was endoscopically and histologically evaluated before and after eradication of this bacterium. The follow-up period was 2-7.1 years. In the other 19 patients in the non-eradication group, gastric metaplasia was evaluated before and after treatment of the ulcer. Gastric metaplasia was evaluated in terms of its extent and type in all patients. Results:Gastric metaplasia showed the incomplete type before eradication but changed to the complete type after eradication, which persisted for a long period. The extent of gastric metaplasia increased after eradication. In the non-eradication group, gastric metaplasia infrequently changed to the complete type during the scarring period of ulcer. Conclusion:Gastric metaplasia changed to the complete type after the eradication of Helicobacter pylori, which persisted for a long period. J. Med. Invest. 50:48-54, 2003 Keywords:gastric metaplasia, Helicobacter pylori, duodenal ulcer, eradication INTRODUCTION In 1964, James (1) observed a high incidence of gastric metaplasia (GM) in patients with duodenal ulcer, and suggested its role in the defense against high gastric acidity. Since the discovery of Helicobacter pylori (H. pylori) in 1983 (2), a close association between this bacterium and duodenal ulcer has been suggested. However, no consistent results or conclusions have been obtained concerning changes in GM after H. pylori eradication. We classified the morphology of GM into 3 types according to the amount of mucus in metaplastic cells and evaluated the long-term course of GM after H. pylori eradication. METHODS Patients The subjects were 59 H. pylori-positive patients with active duodenal ulcers who were undergoing endoscopic examination. Patients who had received antibiotics, acid suppression treatment, or corticosteroids in the previous month or who were receiving nonsteroidal anti-inflammatory drugs were excluded. Patients in whom gastric surgery was performed, or endoscopic biopsy was contraindicated were also excluded. In 40 patients (25 males and 15 females;median age, 51 years;age range, 33-72 years), H. pylori could be eradicated by triple drug therapy with lansoplazole, amoxicillin, and metronidazole (eradication group). In the other 19 patients (13 males and 6 females;median age, 48 years;age range, 26-70 years), H. pylori were not eradicated (non-eradication group). Clinical procedures The eradication group received 1.5 g/day of amoxicillin and 500 mg/day of metronidazole for 1 week, and 30 mg/day of lansoplazole for 6 weeks after initial endoscopic examination, followed by consecutive administration of an H2-receptor antagonist at the standard dose for 4 weeks. The non-eradication group received 30 mg/day of lansoplazole for 6 weeks after initial endoscopy and, in addition, received the same regimen of an H2-receptor antagonist as the successful eradication group. At the initial endoscopy, two paired biopsies were obtained from the greater curvature of the gastric antrum as well as of the gastric corpus in all patients in both groups. Of the two paired biopsies, one was used for the rapid urease test, and the other was placed in 10% buffered formalin for histological examination to confirm H. pylori infection. Two duodenal biopsies were performed from the ulcer margin at the same time and also placed in 10% buffered formalin and processed for the histological examination of GM. All patients in both groups underwent endoscopy again after treatment for 10 weeks. Gastric biopsies were repeated, being obtained from a topographical site similar to that in the initial endoscopy. Two duodenal biopsy specimens were obtained from the center of the scar. The 40 patients in the eradication group were followed up for 2.0-7.1 years (mean, 3.6 years) after confirmation of eradication to evaluate the course of duodenal ulcer and examine for H. pylori. Endoscopy was performed once -7 times (mean, 2.9 times) after the confirmation of H. pylori eradication. At each endoscopy, biopsy specimens were obtained from the stomach and the center of the duodenal ulcer scar by the above-described method. In patients with recurrence, biopsy specimens were obtained from the ulcer margin in the same way as in the initial endoscopy. Of patients who could be followed up in the non-eradication group, 6 did not show recurrence. In the 6 patients, biopsy specimens were obtained from the greater curvature of the gastric antrum and corpus and the center of the duodenal ulcer scar, and H. pylori and GM were examined. The eradication of H. pylori was confirmed by a negative biopsy urease test and negative results of histological examination. Informed consent about the eradication of H. pylori and endoscopic biopsy was obtained from all patients who entered this study. Histological methods Duodenal and gastric sections were routinely processed, cut at 3 µm, and stained with hematoxylin-eosin, alcian blue periodic acid Schiff, and Giemsa stain. Duodenal sections stained with hematoxylin-eosin and alcian blue periodic acid Schiff were used to identify and assess the extent and type of GM. Giemsa stain was used to identify the presence of H. pylori in areas of GM. Hematoxylin-eosin staining of gastric biopsy specimens was performed for histological examination for gastritis, and Giemsa stain was used for the detection of H. pylori. The extent of GM was classified according to our previously reported method:(3-5) grade 0, absence of GM;grade 1, GM involving a few villi;grade 2, GM involving several villi;and grade 3, GM involving almost all villi. GM was classified into 3 types according to the amount of mucus in the metaplastic cells:complete, intermediate, and incomplete (5). The complete type of GM was characterized by tall mucin-abundant cells (Fig. 1). The incomplete type of GM was dark with cuboidal cells poor in mucin (Fig. 2). The intermediate type was between the two types. When the grade differed between the two specimens from the same subject, the higher grade was regarded as the grade for that subject. Statistics Statistical analysis was performed using Wilcoxon's signed rank test. P values < 0.05 were considered significant. RESULTS Changes in GM in the eradication group Table 1 shows changes in the type of GM before and after 10 weeks of treatment in the 40 patients with duodenal ulcer in the successful eradication group. Before eradication (active stage of duodenal ulcer), the incomplete type was observed in 35 of the 40 patients and the intermediate type in the other 5. After H. pylori eradication (scarring stage), the complete type was observed in 39 patients and the intermediate type in the other. Thus, the incomplete type of GM was frequently observed before eradication, but the complete type was primarily observed after eradication (p<0.0001). Before eradication, the extent of GM was graded as 0 in none of the 40 patients, 1 in 13, 2 in 19, and 3 in 8. After eradication, grade 0 was observed in none of the 40 patients, grade 1 in none, grade 2 in 5, and grade 3 in the other 35 (Table 2). The extent of GM after eradication was greater than that before eradication (p<0.0001). Long-term course of GM in the successful eradication group Fig. 3 shows the course of GM after H. pylori eradication in the 40 patients who were followed up for 2 years or more after eradication. In most patients showing a change to the complete type after eradication, this state was maintained for a long period. However, in 5 patients, the complete type changed to the intermediate type during the follow-up period. In 3 patients who became H. pylori-positive again, GM changed to the incomplete type, and the extent of GM also decreased. Of the other 37 patients who were consistently H. pylori-negative, 15 showed a decrease in the extent of GM 1.5-4.5 years after eradication. However, in some patients, grade 3 GM persisted for 3 to 7 years. Changes in GM in the non-eradication group Table 3 shows GM types before (active stage of duodenal ulcer) and after (scarring stage) treatment in the 19 patients with duodenal ulcer in the non-eradication group. Before treatment, the complete type was observed in none of the 19 patients, intermediate type in 3, and the incomplete type in 16. After treatment for 10 weeks, the complete type was observed in 6 patients, intermediate type in 6, and incomplete type in 7. The incomplete type was frequently observed in the active stage while the complete type increased, and the incomplete type decreased in the scarring stage (p=0.0024). The extent of GM before treatment was graded as 1 in 7 patients and 2 in 12, and that after treatment was graded as 2 in 4 patients and 3 in 15 (Table 4). Thus, the extent of GM in the scarring stage was greater than that in the active stage (p<0.0001). Course of GM in patients without ulcer recurrence in the non-eradication group Fig. 4 shows the course of GM in 6 patients without ulcer recurrence during the follow-up period in the non-eradication group. The follow-up period ranged from 7 to 23.5 months (mean, 14.3 months). Before treatment (active stage), all the 6 patients showed the incomplete type. After 10 weeks of treatment (scarring stage), the complete type was observed in 2 patients, intermediate type in 3, and the incomplete type in 1. The extent of GM before treatment was graded as 1 in 2 patients and 2 in 4, but that after treatment was graded as 3 in all the 6 patients. Follow up examination showed a change to the incomplete type again and a decrease in the extent of GM in most patients despite the maintenance of the ulcer scarring stage. Thus, the non-eradication group showed a lower incidence of complete type GM in the scarring stage than the successful eradication group. In addition, the extent of GM, which increased in the scarring stage, decreased after a short period. DISCUSSION GM has been considered to be a protective response to exposure to high acidity in the duodenal bulb (1, 6-8). In the presence of H. pylori infection in the stomach, H. pylori harbors in GM areas, which causes duodenitis (9), leading to duodenal ulcer (8). Concerning changes in GM after H. pylori eradication for duodenal ulcer, Noach et al. (10) and Harris et al. (11) reported no significant differences between the prevalence and extent of GM before eradication and those after eradication. Conversely, Khulusi et al. (12) observed a 42% reduction in the extent of GM after eradication. Therefore, no consistent findings have been obtained. We previously reported that GM presented a well-developed appearance with abundant intracellular mucus after successful eradication and remained in this condition for a long period (4). Previous studies on GM have evaluated the prevalence and extent of GM (8) but rarely the properties of GM. Since there are only a few H. pylori-negative patients with duodenal ulcer, we previously evaluated differences in the properties of GM (5) between the presence and absence of H. pylori infection in patients with endoscopic duodenitis (13). GM showed the complete type in H. pylori-negative patients with endoscopic duodenitis but the incomplete type in H. pylori-positive patients. These findings suggested the importance of the consideration of not only the prevalence and extent of GM but also its type (complete or incomplete) that represents the maturity of H. pylori (5). In this study, most patients with duodenal ulcer showed the incomplete type before eradication but a change to the complete type after eradication and the persistence of the complete type for a long period. However, the patients with recurrence of H. pylori showed a change to the incomplete type again during the follow-up period. In the non-eradication group, GM changed to the complete type with healing of the ulcer in some patients but remained the incomplete or intermediate type in others. In addition, most patients with a change to the complete type after treatment showed a change to the incomplete type again and a decrease in the GM extent grade during the follow-up period. These findings were in contrast to the persistence of the complete type in the eradication group. There have been a few studies on the long-term course of GM after H. pylori eradication, and the results of these studies have been inconsistent (4, 10-12, 14). In this study, long-term follow up (maximum, 7.1 years) of GM revealed the persistence of grade 3 GM extent in most patients until about 2 years after eradication but a subsequent decrease in the grade in some patients. Kim et al. (14) reported that the prevalence and extent of GM did not change until 1 year after H. pylori eradication but decreased slightly4years after eradication. Studies have shown a decrease in acid output after H. pylori eradication in patients with duodenal ulcer, but the observation period in these studies was relatively short (6-12 months after eradication) (15-18). The development of GM is considered to be closely associated with gastric high acidity (1, 19, 20). However, the decrease in acid secretion after eradication may not be adequate to reduce the extent of GM during only the 2-year period after eradication. The results of this study and the study by Kim et al. (14) suggest that a decrease in acid output enough to reduce the extent of GM occurred 2-4 years after eradication in some patients. However, some patients showed the persistence of grade 3 GM for a long period such as 7.1 years. In these patients, acid output that induces GM may have been still sustained. However, even in patients with persistent high acidity, since the complete type of GM containing abundant mucus persists in the environment after H. pylori eradication, the defense against acid may be adequate, and ulcer may not recur (4). The importance of GM in duodenal ulcer may be as follows (Fig. 5). GM develops in the healing process of duodenal erosion and ulcer (3, 19) as a defense mechanism against high acidity (1, 6-8). In an H. pylori-positive environment, GM shows the incomplete type due to invasion and damage by H. pylori. Since the defense against high acidity may be decreased in mucosal areas with incomplete type GM poor in mucus and marked H. pylori-induced inflammation, ulcer may develop in these areas. In the healing stage of ulcer, an increase in the extent of GM and complete type GM are observed in some patients. However, in a consistently H. pylori-positive environment, GM decreases in its extent and changes to the incomplete type again due to H. pylori invasion, and ulcer recurrence is repeated during the persistence of high acidity (4). In patients who are H. pylori-negative or after eradication, complete type GM rich in mucus is observed, and mucosal inflammation is also mild. Therefore, the defense against high acidity is adequate, and ulcer may not develop or recur. REFERENCES 1.James AH:Gastric epithelium in the duodenum. Gut 5:285-294, 1964 2.Warren JR, Marshall BJ:Unidentified curved bacilli on gastric epithelium in active chronic gastritis. Lancet 1:1273-1275, 1983 3.Urakami Y:Gastric metaplasia of surface epithelium in the duodenal mucosa. Nippon Shokakibyo Gakkai Zasshi 72:221-231, 1975 (in Japanese with an English abstract) 4.Urakami Y, Kimura M, Seki H:Gastric metaplasia and Helicobacter pylori. Am J Gastroenterol 92:795-799, 1997 5.Urakami Y, Sano T:Endoscopic duodenitis, gastric metaplasia and Helicobacter pylori. J Gastroenterol Hepatol 16:513-518, 2001 6.Rhodes J:Experimental production of gastric epithelium in the duodenum. Gut 5:454-458, 1964 7.Tatsuta M, Ishii H, Yamamura H, Yamamoto R, Taniguchi H:Enhancement by tetragastrin of experimental induction of gastric epithelium in the duodenum. Gut 30:311-315, 1989 8.Wyatt JI, Rathbone BJ, Sobala GM, Shallcross T, Heatley RV, Axon ATR, Dixon MF:Gastric epithelium in the duodenum:Its association with Helicobacter pylori and inflammation. J Clin Pathol 43:981-986, 1990 9.Wyatt JI, Rathbone BJ, Dixon MF, Heatley RV:Campylobacter pyloridis and acid-induced gastric metaplasia in the pathogenesis of duodenitis. J Clin Pathol 40:841-848, 1987 10.Noach LA, Rolf TM, Bosma NB, Schwartz MP, Oosting J, Rauws EAJ, Tytgat GNJ:Gastric metaplasia and Helicobacter pylori infection. Gut 34:1510-1514, 1993 11.Harris AW, Gummett PA, Walker MM, Misiewicz JJ, Baron JH:Relation between gastric acid output, Helicobacter pylori, and gastric metaplasia in the duodenal bulb. Gut 39:513-520, 1996 12.Khulusi S, Badve S, Patel P, Lloyd R, Marrero JM, Finlayson C, Mendall MA, Northfield TC:Pathogenesis of gastric metaplasia of the human duodenum:Role of Helicobacter pylori, gastric acid, and ulceration. Gastroenterology 110:452-458, 1996 13.Tytgat GNT:The Sydney system:Endoscopic division. Endoscopic appearances in gastritis/duodenitis. J Gastroenterol Hepatol 6:223-234, 1991 14.Kim N, Lim SH, Lee KH, Choi SE:Long-term effect of Helicobacter pylori eradication on gastric metaplasia in patients with duodenal ulcer. J Clin Gastroenterol 27:246-252, 1998 15.Parente F. Maconi G, Sangaletti M, Minguzzi M, Vago L, Porro GB:Behaviour of acid secretion, gastrin release, serum pepsinogen, and gastric emptying of liquids over six months from eradication of Helicobacter pylori on duodenal ulcer patients. A controlled study. Gut 37:210-215, 1995 16.El-Omar EM, Penman ID, Ardill JES, Chittajallu RS, Howie C, McColl KEL:Helicobacter pylori infection and abnormalities of acid secretion in patients with duodenal ulcer disease. Gastroenterology 109:681-691, 1995 17.Harris AW, Gummett PA, Misiewicz JJ, Baron JH:Eradication of Helicobacter pylori in patients with duodenal ulcer lowers basal and peak acid outputs to gastrin releasing peptide and pentagastrin. Gut 38:663-667, 1996 18.Iijima K, Ohara S, Sekine H, Koike T, Kato K, Asaki S, Shimosegawa T, Toyota T:Changes in gastric acid secretion assayed by endoscopic gastrin test before and after Helicobacter pylori eradication. Gut 46:20-26, 2000 19.Patrick WJA, Denham D, Forrest APM:Mucous change in human duodenum;A light and electron microscopic study and correlation with disease and gastric acid secretion. Gut 15:767-776, 1974 20.Kreuning J, vd Wal AM, Kuiper G, Lindeman J:Chronic nonspecific duodenitis. A multiple biopsy study of the duodenal bulb in health and disease. Scand J Gastroenterol 24 (Suppl. 167):16-20, 1989 Received for publication October 21, 2002;accepted December 19, 2002. Address correspondence and reprint requests to Yoshihito Urakami, M.D., Urakami Gastro Clinic, 2-2-2 Kitaokinosu, Tokushima 770-0872, Japan and Fax:+81-88-636-0665.