Digestive Diseases and Sciences, Vol. 36, No. 4 (April 1991), pp. 424--430 Pathogenetic Role of Helicobacter pylori Duodenal Ulcer Disease Multivariate Analysis of Factors Affecting Relapse WAI-MO HUI, JOANA HO, and SHIU-KUM LAM in The pathogenesis of duodenal ulcer disease is multifactorial and the contribution of Helicobacter pylori in relation to the other factors to the release of duodenal ulcer is unknown. To investigate this, we studied 147 patients with endoscopically proven healed ulcers. These patients were randomized to receive either placebo, misoprosto1200 tzg or misoprosto1300 t.~g four times daily, and clinical, personal, physiological and endoscopic characteristics were obtained prospectively. Endoscopy was performed at the active phase of the ulcer and when the ulcer healed. Biopsies were taken from the antrum to assess histologically for: (1) the activity of gastritis as assessed by the degree of polymorph infiltration, (2) the degree of chronic inflammation by the degree of chronic inflammatory cells infiltration and degree of mucosal degeneration, and (3) bacteriolog- ically for the presence of H. pylori. The severity of the gastritis and the bacterial density were graded independently by two pathologists. The patients were assessed at two-month intervals for 12 months or until the ulcer relapsed. The results demonstrated that the relapse rates of duodenal ulcer were similar in the three treatment groups. The relapse rate was higher in the group with higher density of the bacteria (P < 0.05). The degree of gastritis did not affect the relapse rate of duodenal ulcer in either the placebo or misoprostol group or in all patients combined. Stepwise logistic regression analysis identified that increased duodenal inflammation, male sex, early-onset disease, and H. pylori adversely affected relapse of the ulcer. We conclude that multiple factors affect the relapse of duodenal ulcer and H. pylori is one of them. KEY WORDS: Helicobacter pylori; duodenal ulcer; relapse. The pathogenetic role of H. pylori in duodenal ulcer disease is controversial (1, 2). While histological, microbiological (3-5), and immunological studies (6-8) demonstrated an association between the tWO conditions, there is a lack of direct evidence that the bacteria play a pathogenetic role. We previously have demonstrated the occurrence and frequency of the Manuscript received July 9, 1990;revised manuscript received November 2, 1990; accepted November 8, 1990. From the Departments of Medicine and Pathology, University of Hong Kong, Queen Mary Hospital, Hong Kong. Address for reprint requests: Hui Wai Mo, Department of Medicine, University of Hong Kong, Queen Mary Hospital, Pokfulam Road, Hong Kong. 424 bacteria remained unchanged with healing of duode- nal ulcer (9). Recent interests have been centered on the association of the bacteria and the recurrence of duodenal ulcer. Treatment of duodenal ulcers with bismuthate salt results in clearance of the bacteria and is accompanied by improvement in gastritis as well as a lower relapse rate of duodenal ulcer (10-12). Whether this lower relapse rate is related to baCteri- cidal effect of bismuthate salt (13, 14) or other mech- anisms (15-17) remains controversial. Moreover, the contribution, if any, of the bacteria in relation to the other factors that have been reported to affect duode- nal ulcer relapse is unclear. The following study was Digestive Diseases and Sciences, Vol. 36, No. 4 (April 1991) 0163-2116/91/0400-0424506.50/0 9 1991 Plenum Publishing Corporation