H-pylori-negative duodenal ulcer prevalence and causes in 774 patients

The prevalence of H. pylori infection has been reported to be very high in duodenal ulcer (DU) disease, but the precise frequency and causes of H. pyl ori-negative DU are not well known. In some geographical regions, however, a relatively low prevalence of the infection has been described. Our aim wa s to study the frequency and causes of H. pylori-negative DU and to evaluat e whether empirical H. pylori eradication therapy without confirmation of t he infection is justified. In all 774 consecutive patients with an endoscop ic diagnosis of DU were studied prospectively. Exclusion criteria were asso ciated diseases and previous gastric surgery. The use of NSAIDs, antibiotic s (during the last month), and proton pump inhibitors (during the last mont h) was evaluated by means of a specific questionnaire. At endoscopy, two bi opsies from both antrum and corpus were obtained in all 774 patients for hi stologic study (H&E stain). One sample from the antrum for rapid urease tes t, one sample each from the antrum and corpus for culture, and two duodenal biopsies for histologic study were also obtained in the first 307 patients . A [C-13] urea breath test was carried out in the remaining 467 patients. Patients were considered infected if any of the diagnostic tests were posit ive and noninfected when all tests performed were negative. Age (mean +/- S D) was 46 +/- 12 years, 70% were males. NSAID, antibiotic, and proton pump inhibitor use was described, respectively, in 8.9%, 5.8%, and 6.3% of the c ases. H. pylori infection was demonstrated, overall, in 95.3% (95% CI: 93.6 -96.6%) of the patients. H. pylori prevalence increased up to 99.1% (98.1-9 9.6%) if patients taking NSAIDs and/or antibiotics were excluded. Among the 36 H. pylon'-negative patients, 20 (55%) were taking NSAIDs, 9 (25%) were taking antibiotics, and 1 (3%) both of them. Therefore, in only 6/774 patie nts (0.8%) could DU disease be considered truly "idiopathic." Differences w ere demonstrated between H. pylori-positive and -negative patients (univari ate study; chi(2)) with regard to NSAID intake (7% vs 58%; P < 0.0001) and previous antibiotic use (5% vs 28%; P < 0.0001). In the multivariate analys is (logistic regression), NSAID use (OR: 0.06; CI: 0.03-0.13; P < 0.001) an d antibiotic use (OR: 0.23; CI: 0.09-0.59; P < 0.01) were the only variable s that correlated with H. pylori infection. The most important factors asso ciated with H. pylori-negative DU are NSAIDs and prior antibiotic use, and if these agents are excluded, the prevalence of infection in our area is as high as 99%. Therefore, in DU patients not taking NSAIDs and living in are as where previous studies have shown the prevalence of the infection in DU disease to be very close to 100%, empirical H. pylori eradication therapy w ithout confirmation of the infection may be justified.