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The pathology, diagnosis and treatment of helicobacter pylori infection

by Wong, Wai-man

Abstract (Summary)
(Uncorrected OCR) Abstract of thesis entitled

The Pathology, Diagnosis and Treatment of Helicobacter pylori Infection Submitted by Wong Wai Man, Raymond

for the degree of Doctor of Medicine

at The University of Hong Kong in July 2001

The aims of this thesis were 1) to study Helicobacter pylori (H. pylori) related mucosal pathology; 2) to evaluate the best diagnostic test for H. pylori; and 3) to test the efficacy of 3 different therapies for H. pylori infection.

Pseudopyloric metaplasia represents a metaplasia of the pyloric glands and is closely associated with hyperplasia of the mucous neck cells (MNC). Both MNC hyperplasia and pseudopyloric metaplasia were associated with H. pylori gastritis. This lineage expressed TFF2, MUC6, PSTI and lysozyme. Ulcerative associated cell lineage was seen to arise from pre-existing crypts in areas of intestinal metaplasia, and plays no part in the histogenesis of pseudopyloric metaplasia. Intestinal metaplasia, which is a H. pylori related pre-malignant lesion of the gastric mucosa, showed evidence of cell cycle de- regulation in the goblet and Paneth cell lineages but not in endocrine cell lineage, which have considerable implications for the biology of intestinal metaplasia.

Helicobacter pylori infection can be diagnosed by invasive and noninvasive tests.

Five invasive tests and one non- invasive test were evaluated. For routine clinical use, histology, rapid urease test and 13C_ Urea breath test (13C_ UBT) had an accuracy of 100%, 99.7%and 94.5% respectively. For research purposes, the accuracy of two positives out of three diagnostic tests was equally reliable. A new rapid urease test, the PyloriTek test was evaluated for the diagnosis of H. pylori infection before and after eradication therapy. It

is highly accurate and one biopsy from the antrum was reliable. A simplified 75gm 13C_ UBT was evaluated in Chinese population. The optimal delta-value and optimal measurement interval for UBT were 5%0 and 30 minutes respectively. Test meal can be safely omitted. Attempt to decrease the measurement interval to 20 minutes and reduce the dose of 13C_ urea to 50mg produced equally accurate results.

A new quadruple therapy was compared with standard triple therapy for the treatment of H. pylori related duodenal ulcer. Intention-to-treat and per-protocol eradication rates were 'if/%, 86%; 87% and 94% for the 7-day group and the 3-day group respectively. Three-day quadruple therapy is a highly effective and better-tolerated therapy for the treatment of duodenal ulcer diseases. The efficacy of one- week omeprazole, clarithromycin and metronidazole (OCM) versus one- week ranitidine bismuth citrate, clarithromycin and metronidazole (RBCCM) for the treatment of H. pylori infection in high prevalence metronidazole resistance region was studied. H. pylori eradication rates were significantly higher in the RBCCM group when compared to the OCM. H. pylori eradication in RBCCM group was unaffected by metronidazole susceptibility. RBCCM is an effective regimen for the eradication of H. pylori infection in high prevalence metronidazole resistance region. The efficacy of 7-day rabeprazole, (a new proton pump inhibitor) clarithromycin plus amoxycillin versus omeprazole, clarithromycin plus amoxycillin for the treatment of H. pylori infection was studied. The possibility of shorter the treatment duration to 3 days was tested. 7-day rabeprazole- based triple therapy has a similar efficacy when compared to 7- day omeprazole- based triple therapy. The 3-day regimen has an inferior eradication rate when compared to the two other 7-day regimens.

Bibliographical Information:

Advisor:

School:The University of Hong Kong

School Location:China - Hong Kong SAR

Source Type:Master's Thesis

Keywords:helicobacter pylori infections diagnosis treatment

ISBN:

Date of Publication:01/01/2001

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