Surface Hydrophobicity of Gastric Mucosa in Helicobacter pylori Infection: Effect of Clearance and Eradication PATRICK M. GOGGIN, JOS6 M. MARRERO, ROBERT T. SPYCHAL, PETER A. JACKSON, CATHERINE M. CORBISHLEY, and TIMOTHY C. NORTHFIELD Departments of Medicine and Histopathology, St. George’s Hospital Medical School, London, England
Surface hydrophohicity of the gastric mucosa is reduced in peptic ulcer disease and Helicobacter pyZori infection. This abnormality may he caused by H. pyZori or may he an inherent defect. The aim of the present study was to clarify the relationship hetween H. pylori infection and mucosal hydrophohicity by examining the effect of eradication of the patients with (n = 42) organism. H. pylori-positive or without (n = 42) duodenal ulcer were randomized to receive ranitidine, bismuth, or bismuth plus antibiotics. Surface hydrophobicity of gastric mucosa was assessed by measurement of plateau-advancing contact angle. Measurements were performed at presentation, end of treatment, and 1 month later. Contact angle was unchanged after ranitidine (55“ vs. 56’) but increased with bismuth (57”-62”; P < 0.05) and bismuth plus antibiotics (56’-67’; P < 0.0001). One month after treatment ended, contact angles in patients in whom H. pylori was not eradicated were not different from those before treatment (56” vs. 56’) but increased to a value similar to H. pylori-negative controls in patients in whom H. pylori was eradicated (56’-69”; P < 0.0001). It is concluded that reduced mucosal hydrophobicity in peptic ulcer disease is secondary to H. pyZori infection and that this impaired mucoa possible mechanism sal defense provides whereby H. pylori infection predisposes to acid/ peptic digestion.
ince the initial identification and isolation of Helicobacter pylori in 1983,’ there has been increasing evidence to suggest that it plays an important role in the pathogenesis of gastroduodenal disease. H. pylori is found in the gastric mucosa of approximately 90% of patients with chronic active gastritis,’ and eradication of the organism3 is associated with histological resolution. Similarly, H. pylori is found in the antrum of >90% of patients with duodenal ulcer,4 and eradication markedly reduces the relapse rate.5-7 However, the pathogenic mechanism by which H. pylori causes gastritis and predisposes to
peptic ulcer is unclear. Possible candidates include production of a vacuolating toxin, immunopathological effects, and disruption of the gastric mucosal barrier by effects on mucus, phospholipids, or bile acids. Animal studies have suggested that the hydrophobic property of gastric and duodenal mucosa may be important in protection against acid. We have previously validated a technique for measurement of surface hydrophobicity on human endoscopic biopsy specimens’ and showed that in peptic ulcer disease and in H. pylori infection, gastric mucosal hydrophobicity is reduced.g This abnormality in H. pylori infection may be secondary to the presence of the organism or may be a primary mucosal defect, because bacterial adhesion to surfaces is partly dependent on hydrophobic interactions.” Thus the aim of the present study was to clarify the relationship between H. pylori infection and gastric mucosal hydrophobicity, by examining the effect of eradication of the organism on surface hydrophobicity. Materials and Methods Subjects We studied 84 patients [51 men and 33 women; mean age, 50 years (range, 21-79)] with H. pylori infection, including 42 with duodenal ulcer and 42 with gastritis alone. We also studied 40 H. pylori-positive controls comprising patients with dyspepsia in whom esophagogastroduodenoscopy showed no abnormalities and in whom H. pylori could not be detected. Patients who had received either bismuth or antibiotics within the last 2 months or H, antagonists within the last 2 weeks were excluded. Informed consent was obtained from each patient, and the protocol was approved by the hospital ethical committee.
Methods Esophagogastroduodenoscopy was performed after an overnight fast by an investigator who did not perform 0
1992 by the American Gastroenterological 0016-5085/92/$3.00
the hydrophobicity measurements. After examination of the esophagus, stomach, and duodenum, five biopsy specimens were taken from the antrum within 2 cm of the pylorus. Two unfixed biopsy specimens were used for measurement of surface hydrophobicity (see below), and one was used to perform a biopsy urease test (CL0 test; Delta West Ltd., Bentley, Western Australia)” for detection of H. pylori. Two biopsy specimens were fixed in form01 saline for histological examination. Hydrophobicity. Surface hydrophobicity was measured as previously described and validated.’ In brief, immediately after collection, biopsy specimens were rinsed in 0.15 mol/L saline, orientated mucosal side upward on a clean glass slide with the aid of a dissecting microscope, and placed on the specimen stage of a goniometer (RameHart lOO/OO; Rame-Hart, Mountain Lakes, NY). After a period of air drying, when the mucosal surface assumed a matt dullness, the plateau-advancing contact angle formed by a droplet of 0.15 mol/L saline applied to the surface was measured as an index of hydrophobicity. The value for each measurement is the mean of contact angle readings on at least three droplets placed on the mucosal surface. All measurements were performed without knowledge of endoscopic findings or patient details. Histology. After fixation in form01 saline, biopsy specimens were routinely processed. Sections were cut at 4 pm and stained with H&E. Histology was assessed independently by two pathologists (P.A.J. and C.M.C.) without knowledge of clinical findings. Disagreements were resolved by joint review. The presence of acute and chronic inflammation was assessed according to standard criteria and graded mild, moderate, or severe. The presence of H. pylori was also assessed and graded as 0 (absent), 1 (occasional or few), or 2 (moderate or numerous). Study design. Patients were enrolled after endoscopy and baseline measurements on the basis of a positive biopsy urease test results. Initially, 36 patients with H. pyJori infection were stratified according to the presence of duodenal ulcer and randomized in an investigator blind fashion to receive 1 months’ treatment with either an H, antagonist (ranitidine, 150 mg twice a day) or bismuth (DeNoltab, 2 tablets twice a day; Brocades, West Byfleet, Surrey, England), or bismuth for 1 month with amoxicillin, 500 mg three times a day, for 2 weeks. Bismuth was included for its effect on H. pylori. Endoscopy was repeated at the end of treatment and again after 1 month off all treatment. The last dose of treatment was taken on the evening before the first repeat endoscopy, which was performed on a morning list. Interim analysis showed that H. pylori had been eradicated (not detected by histology or biopsy urease test 1 month after cessation of all treatment) in few patients; therefore, the next 48 patients were randomized in a 1:1:2 ratio to receive 1 month of ranitidine, 150 mg twice daily, or 2 tablets of DeNoltab twice daily, or 2 tablets of DeNoltab twice daily for 1 month with metronidazole, 400 mg three times daily, for 1 week to increase the proportion of patients in whom H. pylori was eradicated. Statistics. Results are expressed as mean + 1 SE. Paired or unpaired Student’s t test, analysis of variance (ANOVA), and simple and multiple regression were per-
SURFACE HYDROPHOBICITY IN H. PYLOAI INFECTION
formed as appropriate; significant.
a P level of