Helicobacter pylori: controversies and an approach to management

Helicobacter pylori and gastric cancer in the Middle East: A new enigma?

The Middle East is the home of ethnic groups from three main backgrounds: Semitic (Arabs and Jews), Indo-European (Persians and Kurdish) and Turkic (Turkish and Turkmens). Its geographic location, which has been under continuous influences from Asia, Europe and Africa, has made it an ideal site for epidemiological studies on Helicobacter pylori (H. pylori) infection and genotyping. The gastric cancer rate differs in this region from very high in Iran (26.1/10⁵) to low in Israel (12.5/10⁵) and very low in Egypt (3.4/10⁵). Epidemiological studies showed that the prevalence of H. pylori is almost similar in those countries with a high level of infection in childhood. Importantly, the frequency of vacA s1 and m1 regions and cagA+ genotypes were higher in non Semitic populations who inhabit the North than Semitic populations, the inhabitants of Southern parts of the Middle East. H. pylori infection prevalence, distribution pattern of virulence factors, diet and smoking could not have explained the difference in cancer rate. This reflects the multifactorial aetiology of gastric cancer and suggests that H. pylori infection does not always directly correlate with the risk for gastrointestinal disease, such as gastric cancer. Further detailed investigations and international comparative studies of each risk factor need to be performed to investigate whether this represents a true enigma.

Periodontal therapy improves gastric Helicobacter pylori eradication

The oral cavity has been proposed as a reservoir for H. pylori that could be responsible for the refractoriness of gastric infection to triple therapy (antibiotics, antimicrobials, and proton pump inhibitors). The aim of this study was to evaluate the efficiency of combined periodontal and triple therapy vs. triple therapy alone, in gastric H. pylori eradication in persons with H. pylori in the subgingival biofilm. Individuals positive for H. pylori in their gastric and oral samples, as determined by nested PCR, were treated either with periodontal and triple therapy or with triple therapy alone. Our results indicate that 77.3% of those treated with the combined therapy exhibited successful eradication of gastric H. pylori, compared with 47.6% who underwent only triple therapy. Analysis of these data suggests that periodontal treatment in combination with systemic therapy could be a promising approach to increasing the therapy's efficacy and decreasing the risk of infection recurrence.

Non-ulcer dyspepsia: myths and realities

Dyspepsia can be defined as the presence of upper abdominal pain or discomfort; other symptoms referable to the proximal gastrointestinal tract, such as nausea, early satiety, and bloating, may also be present. Symptoms may or may not be meal related. To be termed chronic, dyspepsia should have been present for three months or longer. Over half the patients who present with chronic dyspepsia have no evidence of peptic ulceration, other focal lesions, or systemic disease and are diagnosed as having non-ulcer (or functional) dyspepsia. Non-ulcer dyspepsia is a heterogeneous syndrome. It has been proposed that this entity can be subdivided into a number of symptomatic clusters or groupings that suggest possible underlying pathogenetic mechanisms. These groupings include ulcer-like dyspepsia (typical symptoms of peptic ulcer are present), dysmotility (stasis)-like dyspepsia (symptoms include nausea, early satiety, bloating, and belching that suggest gastric stasis or small intestinal dysmotility), and reflux-like dyspepsia (heartburn or acid regurgitation accompanies upper abdominal pain or discomfort). The aetiology of non-ulcer dyspepsia is not established, although it is likely a multifactorial disorder. Motility abnormalities may be important in a subset of dyspepsia patients but probably do not explain the symptoms in the majority. Epidemiological studies have not convincingly demonstrated an association between Helicobacter pylori and non-ulcer dyspepsia. Other potential aetiological mechanisms, such as increased gastric acid secretion, psychological factors, life-event stress, and dietary factors, have not been established as causes of non-ulcer dyspepsia. Management of non-ulcer dyspepsia is difficult because its pathogenesis is poorly understood and is confounded because of a high placebo response rate. Until more data are available, it seems reasonable that treatment regimens target the clinical groupings described above. Antacids are no more effective than placebo in non-ulcer dyspepsia, although a subgroup of non-ulcer dyspepsia patients with reflux-like or ulcer-like symptoms may respond to H2-receptor antagonists. However, there is no significant benefit of these agents over placebo in many cases. Bismuth has been shown to be superior to placebo in patients with H. pylori in a number of studies, but these trials had several shortcomings and others have reported conflicting findings. Sucralfate was demonstrated in one study to be superior to placebo, but this finding was not confirmed by another group of investigators. Prokinetic drugs appear to be efficacious, and may be most useful in patients with dysmotility-like and reflux-like dyspepsia.

Metronidazole. A therapeutic review and update

The nitroimidazole antibiotic metronidazole has a limited spectrum of activity that encompasses various protozoans and most Gram-negative and Gram-positive anaerobic bacteria. Metronidazole has activity against protozoans like Entamoeba histolytica, Giardia lamblia and Trichomonas vaginalis, for which the drug was first approved as an effective treatment. Anaerobic bacteria which are typically sensitive are primarily Gram-negative anaerobes belonging to the Bacteroides and Fusobacterium spp. Gram-positive anaerobes such as peptostreptococci and Clostridia spp. are likely to test sensitive to metronidazole, but resistant isolates are probably encountered with greater frequency than with the Gram-negative anaerobes. Gardnerella vaginalis is a pleomorphic Gram-variable bacterial bacillus that is also susceptible to metronidazole. Helicobacter pylori has been strongly associated with gastritis and duodenal ulcers. Classic regimens for eradicating this pathogen have included metronidazole, usually with acid suppression medication plus bismuth and amoxicillin. The activity of metronidazole against anaerobic bowel flora has been used for prophylaxis and treatment of patients with Crohn's disease who might develop an infectious complication. Treatment of Clostridium difficile-induced pseudomembraneous colitis has usually been with oral metronidazole or vancomycin, but the lower cost and similar efficacy of metronidazole, coupled with the increased concern about imprudent use of vancomycin leading to increased resistance in enterococci, have made metronidazole the preferred agent here. Metronidazole has played an important role in anaerobic-related infections. Advantages to using metronidazole are the percentage of sensitive Gram-negative anaerobes, its availability as oral and intravenous dosage forms, its rapid bacterial killing, its good tissue penetration, its considerably lower chance of inducing C. difficile colitis, and expense. Metronidazole has notable effectiveness in treating anaerobic brain abscesses. Metronidazole is a cost-effective agent due to its low acquisition cost, its pharmacokinetics and pharmacodynamics, an acceptable adverse effect profile, and its undiminished antimicrobial activity. While its role as part of a therapeutic regimen for treating mixed aerobic/anaerobic infections has been reduced by newer, more expensive combination therapies, these new combinations have not been shown to have any therapeutic advantage over metronidazole. Although the use of metronidazole on a global scale has been curtailed by newer agents for various infections, metronidazole still has a role for these and other therapeutic uses. Many clinicians still consider metronidazole to be the 'gold standard' antibiotic against which all other antibiotics with anaerobic activity should be compared.

A risk-benefit assessment of drugs used in the eradication of Helicobacter pylori infection

Helicobacter pylori is the cause of chronic active gastritis and predisposes to peptic ulcer disease (PUD). Furthermore, H. pylori is linked to the pathogenesis of gastric lymphoma and gastric cancer. However, treatment of this infection has proven difficult. In the last decade, many antimicrobial compounds have been studied extensively as monotherapy as well as in combination with bismuth or acid-suppressive drugs. The individual drugs and the most important eradication regimens are discussed with special regard to their risks. In the past, highly complex multidrug regimens, fear of adverse effects and frequent eradication failures have hampered the broad acceptance of H. pylori-eradication therapies. Recently, new 1-week, low-dose combination regimens of 2 antibacterials with a proton pump inhibitor have consistently achieved eradication rates of 90% and more with an acceptably low rate of adverse effects. One week's standard triple therapy [tripotassium dicitrato bismuthate (or bismuth salicylate plus metronidazole plus tetracycline or amoxicillin) has been shown to be highly effective and tolerated better in combination with a proton pump inhibitor. This regimen is, however, more complex and has more adverse effects. Therefore, it is not recommended as first-line therapy. Equipped with these therapies physicians can now be strongly encouraged to use H. pylori eradication as the therapy of choice for patients with PUD and even extend this treatment to other H. pylori-associated disease conditions.

Brush cytology: a reliable method to detect Helicobacter pylori

This study was conducted to verify the reliability of brush cytology in detecting Helicobacter pylori in an unselected group of patients with duodenal ulcer (DU) and nonulcer dyspepsia (NUD). Endoscopy was performed on 416 consecutive patients: group A, 94 with active DU; group B, 176 patients with DU after omeprazole (n = 78), ranitidine (n = 43), or triple anti-H. pylori therapy (n = 55); and group C, 146 patients with NUD. During endoscopy, the gastric mucosa was brushed and two biopsy samples from the antrum and body were obtained for histology. In 65 patients, culture of the brush-collected materials also was performed as was that from of biopsy samples. The overall frequency of H. pylori presence detected by brush cytology was significantly higher compared with that of histology (p < 0.001), particularly in group A (p < 0.05), group C (p < 0.05), and in patients with DU after omeprazole treatment (p < 0.01), but not in patients with DU after ranitidine or anti-H. pylori treatment. The overall frequency of H. pylori-positive cultures from the brush-collected material was higher compared with cultures from the biopsy samples (38.5% vs. 24.6%), particularly in the NUD group (32.6% vs. 16.3%). Brush cytology is more sensitive than histology, besides being faster and cheaper, for the assessment of H. pylori infection, particularly when the density of the bacteria is low.

Are duodenal ulcer seasonal fluctuations paralleled by seasonal changes in 24-hour gastric acidity and Helicobacter pylori infection?

The occurrence of duodenal ulcer is characterized by seasonal variation, for poorly understood reasons. No previous study has assessed whether 24-h intragastric acidity and Helicobacter pylori infection have similar seasonal fluctuations in patients with this disorder. For this reason, we evaluated retrospectively the circadian gastric pH in 319 new patients (226 men and 93 women, mean age 45.2 years) with endoscopically proven duodenal ulcer, who agreed to undergo this examination during the years 1987-1992 in our center. The month-by-month occurrence of the disease over the global 6-year period was assessed, and the mean pH values were calculated for each patient during three time intervals of interest: 24 h, daytime (08:00-19:59 h), and nighttime (20:00-07:59 h). The mean pH values of these three time periods were then calculated month by month throughout the annual cycle. H. pylori infection was sought by histology in 171 patients examined in the period from 1990 to 1992. The percentage of H. pylori-positive duodenal ulcer patients was then calculated for each season. The calendar fluctuation of duodenal ulcer occurrence showed an evident increase (p < 0.001) in fall (October-December) and in winter (January-March) compared with spring (April-June) and summer (July-September). Both 24-h and nighttime gastric acidity showed no significant variation by month, whereas daytime gastric pH varied significantly (p < 0.05) with two evident decreases, meaning higher acidity, in April and August. H. pylori infection was detected in 152 of 171 patients (89%), and the percentage of H. pylori-positive duodenal ulcers did not differ from season to season. We conclude that there was no parallel circannual fluctuation of duodenal ulcer, gastric acidity, and H. pylori infection in the restricted sample of patients we studied. This reduces the apparent relevance of acid in inducing ulcer seasonal fluctuation. Also, the responsibility of H. pylori in this phenomenon can be excluded until a reliable diagnostic method capable of distinguishing recent from old infection is found.

Effect of omeprazole on concentrations of clarithromycin in plasma and gastric tissue at steady state

This study was conducted to determine (i) the effect of omeprazole on steady-state concentrations of clarithromycin and 14-(R)-hydroxyclarithromycin in plasma and gastric mucosa, (ii) the effect of clarithromycin on steady-state concentrations of omeprazole in plasma, and (iii) the effect of clarithromycin on the suppression of gastric acid secretion by omeprazole. Twenty healthy, Helicobacter pylori-negative male subjects completed this three-period, double-blind, randomized crossover study. In period 1, all subjects received 40 mg of omeprazole each morning for 6 days. Twenty-four-hour gastric pH monitoring took place on days -1 and 6. Pharmacokinetic sampling took place on day 6. In periods 2 and 3, subjects were randomly assigned to receive either 40 mg of omeprazole or omeprazole placebo daily for 6 days plus clarithromycin (500 mg) every 8 h for 5 days with a single 500-mg dose on day 6. Gastric tissue and mucus samples were obtained via endoscopy on day 5. Gastric pH monitoring and pharmacokinetic sampling took place on day 6. Two-week washout intervals separated the three study periods. Clarithromycin increased mean omeprazole area under the concentration-time curve from 0 to 24 h from 3.3 +/- 2.0 to 6.3 +/- 4.5 micrograms.h/ml (P < 0.05) and harmonic mean half-life from 1.2 to 1.6 h (P < 0.05) but did not significantly alter the effect of omeprazole on gastric pH. Mean clarithromycin area under the concentration-time curve from 0 to 8 h increased from 22.9 +/- 5.5 (placebo) to 26.4 +/- 5.7 micrograms.h/ml (omeprazole) (P < 0.05) when clarithromycin was administered with omeprazole. Analysis of variance revealed that mean concentrations of clarithromycin in tissue and mucus were statistically significantly higher when clarithromycin was given with omeprazole than when clarithromycin was given with placebo (P <0.001). Mean maximum observed concentrations of clarithromycin in the gastric fundus increased from 20.8 +/- 7.6 (placebo) to 24.3 +/- 6.4 micrograms/g (omeprazole), and those in the gastric mucous from 4.2 +/- 7.7 placebo to 39.3 +/- 32.8 micrograms/g (omeprazole). Similar increases were observed for the 14-(R)-hydroxyclarithromycin. These results show that omeprazole increases concentrations of clarithromycin in gastric tissue and mucus and may provide a mechanism for synergy between clarithromycin ad omeprazole that explains the excellent eradication of H. pylori seen in clinical trials.

Accuracy of invasive and noninvasive tests to diagnose Helicobacter pylori infection

BACKGROUND & AIMS

Multiple tests are available for determining Helicobacter pylori infection. Our aim was to compare the sensitivity, specificity, and negative and positive predictive value of the most widely available tests for diagnosis of H. pylori.

METHODS

A total of 268 patients (mean age, 53.7 +/- 15.8 years; 142 male and 126 female; 125 white and 143 nonwhite) was tested for H. pylori infection by [13C]urea breath test (UBT), measurement of serum immunoglobulin (Ig) G and IgA antibody levels, and antral biopsy specimens for CLO test, histology, and Warthin-Starry stain. No patient received specific treatment for H. pylori before testing. The infection status for each patient was established by a concordance of test results.

RESULTS

Warthin-Starry staining had the best sensitivity and specificity, although CLO test, UBT, and IgG levels were not statistically different in determining the correct diagnosis. The absence of chronic antral inflammation was the best method to exclude infection. Stratification of results by clinical characteristics showed that UBT and chronic inflammation were the best predictors of H. pylori status in patients older than 60 years of age. IgA was a better predictor in white patients.

CONCLUSIONS

The noninvasive UBT and IgG serology test are as accurate in predicting H. pylori status in untreated patients as the invasive tests of CLO and Warthin-Starry.

Endoscopic and histologic resolution of gastric pseudolymphoma (reactive lymphoid hyperplasia) following treatment with bismuth and oral antibiotics

Gastric pseudolymphoma is a rare disorder of unknown etiology that can undergo transformation into malignant lymphoma. This report describes the first case of a gastric pseudolymphoma associated with Helicobacter pylori infection that underwent complete clinical, endoscopic, and histologic resolution following treatment with bismuth subsalicylate, amoxicillin, and metronidazole. The eradication of Helicobacter pylori may have eliminated ongoing antigenic stimulation that has previously been postulated to be responsible for the development and subsequent progression of gastric pseudolymphoma.

Helicobacter pylori is associated with alterations in intestinal gas profile among patients with nonulcer dyspepsia

The pathogenesis of nonulcer dyspepsia (NUD) is unknown. Gas and postprandial bloating are frequent symptoms. The role of Helicobacter pylori (HP) in the pathogenesis of NUD is controversial. We studied the intestinal gas profile of NUD patients (N = 34) at baseline and after lactulose administration. The prevalence of hydrogen and methane producers was similar among HP+ and HP- patients. Breath H2 concentrations in response to lactulose showed significantly greater rise among HP+ subjects (P < 0.0001). HP positivity was associated with higher total breath excretion for H2 and methane combined (2984 +/- 1038 vs 1776 +/- 521 ppm/hr) compared to HP- subjects (P < 0.05). There was no correlation between peak H2 and methane levels. The role of alterations in intestinal gas in producing symptoms in HP+ patients with NUD needs further investigation.

A pharmacodynamic study of two omeprazole regimens suitable for long-term treatment of duodenal ulcer

BACKGROUND

The experience with long-term treatment of peptic ulcer with omeprazole is still scant, but the possibility cannot be excluded that its better pharmacodynamic effect on gastric acidity also has a positive result in the relapse rate. Moreover, this drug acts via a mechanism other than receptorial binding, and therefore its efficacy should not dissipate with time. This study was carried out to assess the pharmacodynamic properties and the possible changes with time of two dose regimens of omeprazole that could be suitable for long-term treatment in duodenal ulcer.

METHODS

Twenty patients with endoscopically proven duodenal ulcer were studied by means of 24-h gastric pH-metry both in basal conditions and on the 5th day of acute treatment with 40 mg omeprazole in the morning. All the ulcers healed after 4 weeks, and thereafter 10 patients were randomized to receive orally 20 mg omeprazole daily at 0800 h in single-blind fashion (group A) and 10 to receive 20 mg omeprazole every other day (group B) for up to 6 months. At the end of the 1st, 3rd, and 6th month of these maintenance treatments 24-h gastric pH-metry was repeated to assess the antisecretory effect of each regimen over time. In group-B patients the test was performed on 2 consecutive days (without and with medication) at each time interval. The fasting gastrin values were also determined. The patients underwent esophagogastroduodenoscopy every 2 months.

RESULTS

Three patients in group B were lost to follow-up for various reasons, and only seven remained eligible for final analysis. The two long-term regimens of omeprazole were able to increase significantly pH values (p < 0.02-0.001) and the times spent at and above pH 3.0 (p < 0.001) over 24 h compared with basal conditions. In group A the 24-h pH value obtained in the 6th month was higher (p < 0.02) than that in the 3rd month of maintenance treatment. In group B the pharmacologic effect tended to decrease on the day without medication compared with the day with medication, but the difference between them was significantly (p < 0.05) only at the 6-month interval. There was no significant difference between the gastrin levels of the two groups in the long-term treatment. No ulcer relapse was detected at any long-term endoscopic control in the two groups of patients.

CONCLUSIONS

The two omeprazole regimens we tested are effective in reducing gastric acidity, and their pharmacodynamic action does not decrease with time. They are therefore suitable for maintenance treatment in acid-related disorders.

Phospholipase A2 activity in gastric juice from patients with active and H. pylori-eradicated healed duodenal ulcer

BACKGROUND

Despite the close association between gastric Helicobacter pylori infection and duodenal ulcer, little is known about how this organism may promote mucosal damage. A possibility might be that it produces, or induces the host to release, phospholipases that metabolize the protective layer of phospholipids.

METHODS

Aimed at determination of phospholipase A2 activity and the concentration of choline-containing phospholipids in gastric juice, aspirates were collected during gastroscopy in 38 consecutive referrals with either active (n = 19) or H. pylori-eradicated healed duodenal ulcer (n = 19).

RESULTS

Gastric juice phospholipase A2 activity was 3.1 times higher in active than in healed duodenal ulcers (P = 0.03). Concurrently, the concentration of choline-containing phospholipids in the group with active ulcers was less than half compared with the healed group (P = 0.02).

CONCLUSION

The results indicate that phospholipase A2 activity and the concentration of choline-containing phospholipids in gastric juice are related to H. pylori status and duodenal ulcer disease.

Helicobacter pylori infection in a randomly selected population, healthy volunteers, and patients with gastric ulcer and gastric adenocarcinoma. A seroprevalence study in Taiwan

To investigate the association of Helicobacter pylori and gastric ulcer and adenocarcinoma, IgG antibodies against H. pylori were examined in 823 randomly selected subjects, 92 healthy volunteers, 117 patients with gastric ulcer, and 148 with gastric adenocarcinomas in Taiwan, where the prevalence of gastric adenocarcinoma is high. The seropositivity of this population in Taiwan was 54.4%. Gastric ulcer patients had a higher seropositivity (83.8%) than healthy volunteers (62.0%) and gastric adenocarcinoma patients (62.2%) (P < 0.001). Gender difference, blood type, and habit of smoking were not associated with the seroprevalence in any study groups. Gastric ulcer coexistent with duodenal ulcer had a higher seropositivity (94.7%) (P < 0.05). The seropositivity of H. pylori in gastric adenocarcinoma patients was higher than in healthy volunteers only in younger age and was not associated with histologic type, invasion, and location of major tumors. The results reemphasize the association of H. pylori infection with gastric ulcer but not with gastric adenocarcinoma in Taiwan.

Role of Helicobacter pylori serology in evaluating treatment success

Duodenal ulcer recurrence and gastritis are reduced with successful Helicobacter pylori treatment. Serology is accurate in the diagnosis of H. pylori, but its value in determining eradication is unproved. To evaluate the usefulness of serology in monitoring treatment, we measured serial serum antibodies in three patient groups: eradication success (N = 57), eradication failure (N = 19), and untreated patients (N = 24). Eradication was determined by Warthin Starry staining of antral biopsies and repeat 13C breath tests at six weeks. Subsequent 13C breath tests were then performed at three-month intervals to monitor eradication. IgG antibody concentrations to H. pylori were determined by a commercially available ELISA kit. Serology concentrations remained constant throughout the study period in the untreated patients. IgG concentrations decreased slightly in the treatment failure group at six weeks but thereafter remained at baseline values. In the eradicated group, serum IgG concentrations decreased 26% by three months, 43% by six months and 55% at nine and 12 months (P < 0.001). A 20% reduction in IgG concentrations by six months was associated with successful treatment (sensitivity 86% and specificity 88%). We conclude that serology is a potentially useful way to monitor H. pylori treatment success.

Asymptomatic H. pylori infection impairs pH inhibition of gastrin and acid secretion during second hour of peptone meal stimulation

H. pylori infection is associated with acid-peptic disease, although its role in the pathogenesis is unclear. The purpose of this study was to determine if chronic infection in asymptomatic subjects impairs the inhibition of meal-stimulated gastrin and acid secretion that is observed normally at low intragastric pH. Presence of infection was determined by both C-14 urea breath test and serology. Acid secretion was measured under basal conditions and in response to peptone meal stimulation and pentagastrin. Plasma gastrin concentrations were determined by radioimmunoassay under basal conditions and during peptone meal stimulation. Intragastric titration with 1% peptone during the first hour, and 8% peptone during the second hour, was performed at both pH 7.0 and 2.5 on different days to compare the inhibition of gastrin and acid secretion. Compared to noninfected subjects, asymptomatic individuals infected with H. pylori had significantly increased: (1) basal gastrin values (P < 0.005); (2) 8% peptone-stimulated gastrin responses at both pH 7.0 and 2.5 (P < 0.05); and (3) 8% peptone-stimulated acid output at pH 2.5 (P = 0.01). During the second hour of peptone-stimulation, subjects infected with H. pylori had significantly decreased inhibition of gastrin (52% vs 95%) (P = 0.002) and acid (30% vs 81%) (P = 0.01) secretion from pH 7.0 to 2.5. Thus, chronic infection with H. pylori results in impaired inhibition of gastrin and acid secretion at low intragastric pH during the second hour of peptone meal stimulation. These defects may be unrelated to the pathogenesis of acid-peptic disease, since they occur in asymptomatic subjects infected with H. pylori.

Circadian acidity pattern in prepyloric ulcers: a comparison with normal subjects and duodenal ulcer patients

We used continuous 24-h pH monitoring to compare the circadian intragastric acidity of 36 patients with prepyloric ulcers (PPU) with that of 101 normal subjects (NS) and that of 206 patients with duodenal ulcer (DU). The ulcer crater was endoscopically ascertained in all cases, and PPU were located within an area up to 2 cm proximal to the pylorus. The pH curve pertaining to DU patients ran below that of NS during most of the circadian period, whereas the pH profile of PPU patients was higher than that of NS, and this was particularly true during the evening and the night. The acidity of PPU patients was significantly lower (p < 0.01) than that of NS during the night only, whereas it was lower (p < 0.05-0.001) than that of DU patients during each time interval analysed (24 h, nighttime, and daytime). Our findings show that the gastric acidity of PPU patients differs greatly from that of DU patients, since it is lower throughout the whole 24-h period, and particularly during the night. Thus these two entities are pathophysiologically different with regard to the acidity pattern and should be considered two distinct subgroups of peptic ulcer disease instead of being incorporated, as usually happens, in the clinical group 'duodenal ulcer disease'.

Prevalence of Helicobacter pylori in gastrointestinal disorders and concentrations of ciprofloxacin in serum and gastric mucosa

Endoscopic antral biopsies were obtained from 30 patients with several gastrointestinal disorders and analysed for the presence of H. pylori. This bacterium was present in 80% and 58%, respectively, of patients with either gastric and duodenal ulcers and gastric neoplasm. In none of the healthy individuals, H. pylori could be found. Another 14 patients with various diseases of the stomach, undergoing a major gastric resection, had been treated with 200 mg ciprofloxacin intravenously immediately before the operation. Blood and various tissues samples were taken during the operation. The prevalence of IgG antibodies against H. pylori in these patients was 93%. H. pylori could be determined in 71% of the cases by the urease production; by culture, this was possible in only one case. The mean peak concentration of ciprofloxacin in serum was 5.31 mg/l and 1.17 mg/l, respectively, immediately and 60 min after the end of infusion; in tissues of antrum and duodenum, 1.59 to 1.64 mg/kg and 1.41 to 1.72 mg/kg, respectively, 45-270 min after the infusion. The results show that ciprofloxacin rapidly penetrates into tissues and attains concentrations greater than the MIC90 for H. pylori. However, these concentrations can inhibit the isolation of this microorganism but not its urease activity. This fact could be interpreted by the existence of a nonculturable but metabolically active form of H. pylori. This would explain the high rate of recrudescence following most types of currently applied therapeutic schemes.

Social and geographical risk factors in Helicobacter pylori infection

A correlation between childhood crowding and the later development of gastric cancer has been demonstrated by Barker and colleagues, who proposed that the relationship was the consequence of infection by an organism such as Helicobacter pylori. In order to test this hypothesis the presence of IgG antibodies to H. pylori in sera from blood donors in North Wales has been investigated. During donation sessions, donors answered questions relating to social conditions and domicile in childhood (at age 10 years) and adult life (the preceding 2 years). A stepwise logistic regression analysis of the data demonstrated significant independent relationships between seropositivity and the following factors: sharing a bed in childhood, housing density, locality of birth, adult social class and age.

Comparison of commercial serological tests for detection of Helicobacter pylori antibodies

Serological testing for Helicobacter pylori infection is one of the diagnostic methods of choice. Various commercial kits that use different antigens have been developed, but data on their diagnostic accuracy and direct comparisons between the tests are lacking. We aimed to evaluate the sensitivity, specificity, and predictive value of three immunoglobulin G enzyme-linked immunosorbent assay kits: Pylori stat, Helico-G, and Premier H. pylori. Serum samples and gastric biopsy findings from 76 patients were evaluated. We found by using a priori cutoff values that the Pylori stat, Helico-G, and Premier kits had overall sensitivities of 96, 96, and 88%, respectively, and specificities of 94, 86, and 96%, respectively, compared with gastric biopsy findings. For 232 serum samples, the Pylori stat test and a previously validated standard serological assay on which the test was based disagreed in 3% of the cases, while for 76 samples that were tested, Helico-G and a previously validated standard assay on which it was based disagreed in 8% of the cases. The intra- and interassay precision of each of the test kits was high. We conclude that serology based on any of these commercial tests represents a reliable and valid method for the diagnosis of H. pylori whether or not highly purified antigens are used.

Eosinophil cationic protein and phospholipase A2 activity in human gastric juice. With emphasis on Helicobacter pylori status and effects of antacids

To elucidate possible new effects of antacids, gastric juice from 15 volunteers with known Helicobacter pylori status were analysed for eosinophil cationic protein (ECP), phospholipase A2 (PLA2) activity, phosphatidylcholine (PC), and bile acids (BA) before and after administration of one tablet of antacid or placebo in a double blind cross-over design. Geometric mean ECP concentrations were more than 13 times higher in gastric juice from H. pylori-positive (12.9 micrograms/l) than from H. pylori-negative (0.97 micrograms/l) subjects (p = 0.0032). Geometric mean PLA2 activity was 1.31 U/l for the negative subjects and 4.02 U/l for the positive subjects (p = 0.13). There were no differences between positive and negative subjects with regard to either PC or BA concentration. Regardless of H. pylori status, mean PC concentration increased significantly after antacids as compared with placebo (p = 0.024). The effect of antacids did not differ significantly from placebo for ECP, PLA2 activity, or BA concentration. Hence, antacids may not act by binding 'toxic' H. pylori-associated gastric juice components like ECP or PLA2. Increased concentration of PC may indicate an increased protective capacity induced by antacids.

Helicobacter (Campylobacter) pylori in gastric brushing cytology

Helicobacter (formerly Campylobacter) pylori is frequently associated with chronic gastritis and peptic ulcer and has been implicated as an etiologic agent. Identification of H. pylori is important for specific treatment with antibiotics and bismuth compounds. We studied 27 patients who presented with symptoms of gastritis or peptic ulcer on whom paired gastric biopsies and gastric brushings for cytology had been performed. Biopsies were stained with H & E and Warthin-Starry or Giemsa for H. pylori. Previously, Papanicolaou-stained brushings were restained with Giemsa and reviewed blindly by two cytologists. Cytologic examination revealed the characteristic 1-3 mu curved or spiral gram-negative bacilli embedded in mucus in 12 of 27 (44%) of cases. Biopsies showed H. pylori in 13 of 27 (48%) of cases. Cytology and histology were concordant in 22 of 27 (81%) of cases. Three cases were positive on biopsy, negative on cytology; two of these were unsatisfactory cytology specimens. Two cases were positive on cytology, negative on biopsy, apparently sampling artifacts. Papanicolaou-stained slides were scored for several morphologic parameters; numbers of acute and chronic inflammatory cells and degree of cytologic atypia. None of these were predictive of the presence of H. pylori. We conclude that Giemsa-stained gastric brushings are a useful complement to gastric biopsies in establishing the diagnosis of H. pylori.

Biometric evaluation of gastric urease activity in man

The 14C-urea breath test is claimed to be the best test for detection of Helicobacter pylori infection. We present a procedure for estimating its cutoff value on the basis of biometric evaluation only, without involving other diagnostic methods. Cumulative gastric urease activity (CA) was determined during the first 30 min after oral administration of 14C-urea (92.5 kBq) in 56 random volunteers and 49 consecutive patients with peptic ulcer disease. The distribution of CA in random volunteers was positively skewed. Logarithmic transformation yielded two separate populations, each normally distributed. Their normal probability density functions intercepted at log cutoff value. A bimodal distribution of log CA was confirmed in patients with peptic ulcer disease before and after treatment aimed at H. pylori eradication. Cutoff values were determined for both random volunteers and patients with peptic ulcer disease. By application of the present procedure for determination of cutoff value, the 14C-urea breath test distinguishes between individuals who have an increased gastric urease activity and individuals who do not, with the smallest possible arbitrariness.

Management of gastroduodenopathy associated with use of nonsteroidal anti-inflammatory drugs

Adverse events associated with the use of nonsteroidal anti-inflammatory drugs (NSAIDs) are reported more frequently to the Food and Drug Administration than are those associated with any other group of drugs. The absolute risk for serious gastrointestinal events--in particular, ulcer bleeding, perforation, and death--is controversial; some investigators believe that an epidemic of NSAID-related complications is being experienced, whereas others suggest that the risks are being overemphasized. The management of patients who take NSAIDs regularly also remains controversial. Key unresolved issues include how best to identify those patients at particularly high risk for the development of ulcer complications and whether such patients should receive prophylactic therapy in an attempt to prevent such problems. In this review, we critically evaluate the currently available literature and present a management algorithm for the treatment and prevention of NSAID-associated gastroduodenopathy.

Serodiagnosis of Helicobacter pylori: comparison of enzyme-linked immunosorbent assays

Enzyme-linked immunosorbent assays (ELISAs) have been developed to diagnose Helicobacter pylori infection. However, the methods are not standardized. We therefore prospectively evaluated the sensitivities and specificities of ELISAs developed in the United States and the United Kingdom in a study population comprising 41 consecutive symptomatic outpatients and 35 volunteers. At endoscopy, multiple biopsies were obtained for histology and culture and stained sections were graded for chronic gastritis, active chronic gastritis, and density of H. pylori. Serum samples were analyzed for H. pylori by ELISA. The first set of assays for immunoglobulin G (IgG) and IgA used a pool of sonicated isolates of H. pylori from five patients in the United States (antigen A). The second set of assays, developed in the United Kingdom, used three different antigens: antigen 1, an acid-extractable surface antigen; antigen 2, an acid-extractable antigen from an aflagellate variant; and antigen 3, a urease-containing fraction. Cutoff scores for positive results were determined a priori on the basis of previous serological studies. There was close agreement between histology and culture. In the study population, 36% of the individuals were H. pylori positive. The diagnostic value of the different ELISAs were highly comparable, and the crude antigens performed as well as the more purified antigens. The antigen A IgG had a sensitivity and specificity of 96 and 94%, respectively; the values for antigen 1 were 93 and 96%, respectively. The antigen A IgA and antigen 3 assays were the least sensitive tests.(ABSTRACT TRUNCATED AT 250 WORDS)

Helicobacter pylori: histological and serological study on gastric and duodenal ulcer patients in Estonia

We have examined the occurrence of Helicobacter pylori (HP) infection in 86 Estonian gastric ulcer (GU) and 25 duodenal ulcer (DU) patients. Diagnosis of the HP infection was made histologically (modified Giemsa) from gastric biopsy specimens, and serologically by parallel use of two enzyme-linked immunosorbent assays for IgG antibodies to HP in patient sera. The infection was diagnosed simultaneously by all three methods in 84% of the GU and 84% of the DU patients. The infection was revealed histologically in 88% of the GU and 92% of the DU patients, and serologically by either of the two methods in 94% and 92% of the GU and DU patients, respectively. HP infection was absent by all three methods in one GU patient only, this patient being the only subject who showed normal gastric mucosa in conventional histology. These observations show that HP infection is very common in patients with peptic ulcer in Estonia. In addition, the findings suggest that the serological assays will find a small proportion (15%) of ulcer patients with antibodies against HP but no histologically detectable bacteria.

[14C]urea breath test for diagnosis of Helicobacter pylori

H. pylori is a potent urease producer, a characteristic that has been exploited in the development of the [14C]- and [13C]urea breath tests. The prevalence of H. pylori infection also is known to increase with advancing age; however, the individual patient's age has not routinely been considered when interpreting urea breath test results. The aim of this study was to validate a short, age-adjusted [14C]urea breath test for use in diagnosing H. pylori infections. Forty-one subjects (28 volunteers, 13 patients) underwent esophagogastroduodenoscopy with biopsies. Subjects were defined as being H. pylori-positive if histology or culture was positive. In addition, all subjects completed a 120-min [14C]urea breath test. A logistic regression analysis adjusting for age was used to estimate the probability of H. pylori positivity as a function of the 14C values generated. Sixteen subjects were H. pylori-positive, and 25 were H. pylori-negative. The 14C values generated between 15 and 80 min were found to be equally predictive in identifying H. pylori-positive subjects. Advancing age was associated with a higher probability of H. pylori-positivity. By taking advantage of the statistical probabilities, older patients could be accurately diagnosed with H. pylori at lower 14C values. We found that [14C]urea breath test to be both a sensitive and specific test that can be abbreviated to a 30-min examination (total test time). Moreover, our mathematical model indicates that a patient's age should be considered in order to optimize interpretation of the [14C]urea breath test, although further observations are needed to confirm this model.