Serology for Helicobacter pylori compared with symptom questionnaires in screening before direct access endoscopy

Validation of health screening questionnaire used for screening gastrointestinal disorder in worker's special health examination for night time work

Background

Since the night time work was introduced as a ‘harmful factor’ for the worker's special health examination (WSHE) in 2014, the validation of the questionnaire used for screening gastrointestinal (GI) disorder has not been conducted. The purpose of this study is to verify the validity of the questionnaire using the data of specific health screening cluster.

Methods

We used WSHE screening data for 3 years, from 2014 to 2016, in health screening cluster. The subjects who had received upper GI endoscopy in opportunistic screening and WSHE simultaneously regardless of the results of the questionnaire were selected. We tested the validity of the questionnaire using upper GI endoscopy as a gold standard.

Results

This study was conducted on 5,057 examinees in 2014, 8,352 examinees in 2015, and 10,587 examinees in 2016. The validity of the questionnaire for each year was as follows: sensitivity 12.3% (95% confidence interval [CI], 11.1–13.4), specificity 88.6% (95% CI, 87.2–90.1), accuracy 41.1% (95% CI, 39.8–42.5) in 2014, sensitivity 5.9% (95% CI, 5.2–6.5), specificity 93.6% (95% CI, 92.7–94.4), accuracy 38.6% (95% CI, 37.6–39.6) in 2015, sensitivity 6.0% (95% CI, 5.4–6.5), a specificity of 9.42% (95% CI, 93.4–95.0), accuracy of 34.2% (95% CI, 33.3–35.1) in 2016. In generally, questionnaire showed sensitivity of 10%, specificity of 90%, and accuracy of 40%.

Conclusions

Despite the purpose of WSHEs aiming to identify target disease early, the sensitivity of the questionnaire for GI disease was too low as 10%. The reasons for this are the problem of the question itself, and the problem of ambiguous target disease. In the future, the questionnaire should be improved to meet the purpose of the WSHE, and further correction of the target disease should be made.

Cost-effectiveness of a 'score and scope' strategy for the management of dyspepsia

OBJECTIVE

It is important to identify the best initial work-up in patients with uninvestigated dyspepsia because of its epidemiological and economical relevance. The objective of the study was to assess systematically the effectiveness and cost-effectiveness of invasive and non-invasive strategies for the management of dyspepsia.

METHODS

A decision analysis was performed to compare prompt endoscopy, score and scope, test and scope, test and treat, and empirical antisecretory treatment. Published and local data on the prevalence of different diagnoses, rates of Helicobacter pylori infection, accuracy values of diagnostic tests, and effectiveness of drug treatments were used. The perspective of analysis was that of the public healthcare payer, and only direct costs were included, with a one-year post-therapy time horizon. The main outcome measure was cost per asymptomatic patient, valued in 2003 Euros.

RESULTS

Endoscopy was found to be the most effective strategy for the management of dyspepsia (38.4% asymptomatic patients), followed by test and scope (35.5%), test and treat (35.3%), score and scope (34.7%), and empirical treatment (28.5%). Incremental cost-effectiveness ratios showed that score and scope was the most cost-effective alternative (483.17 Euros per asymptomatic patient), followed by prompt endoscopy (1396.85 Euros). Sensitivity analyses showed variations when varying the values of prevalence of duodenal ulcer, and the values of healing of functional dyspepsia with antisecretory and eradication drugs. There were no changes when varying the prevalence of H. pylori in dyspepsia.

CONCLUSIONS

We would recommend stratifying patients by a score system, referring first to endoscopy those patients at higher risk of organic dyspepsia.

A rational approach to uninvestigated dyspepsia in primary care: review of the literature

In this paper the rationale and limitations of the four most important approach strategies to dyspepsia in primary care (empiric treatment, prompt endoscopy, "test-and-scope", and "test-and-treat") are analysed. It is concluded that in the absence of alarm symptoms, a "test-and-treat" approach is currently the most rational approach provided that three conditions are met: (1) a highly accurate test should be used, (2) the prevalence of Helicobacter pylori in the population should not be too low, and (3) an effective anti-H pylori regimen should be prescribed taking sufficient time to instruct and motivate the patient.

Management of uninvestigated dyspepsia: review and commentary

Up to 40% of individuals complain of dyspepsia but only 25% of these present to their general practitioner. If symptoms have been present for a relatively short period the majority can be managed by reassurance and symptomatic treatment. Those with a longer history require empirical treatment with more powerful medication, endoscopy, testing for Helicobacter pylori, or a combination of these approaches. There is some debate about whether the treatment of Helicobacter pylori infection is an appropriate strategy for patients with dyspepsia. It is the general practitioner who determines how the uninvestigated patient with dyspepsia will be managed because those referred to hospital usually undergo endoscopy at an early stage.

Helicobacter pylori "test-and-scope" strategy for dyspeptic patients. Is it useful and safe?

AIM

To evaluate outcome of test-and-scope strategy using 13C-urea breath test, Helicobacter pylori IgG serology, and CagA serology.

PATIENTS AND METHODS

A series of 100 dyspeptic patients were studied. Biopsies were obtained for histology and rapid urease test (gold standard). Serum samples were obtained for Helicobacter pylori IgG and CagA serology, and 13C-urea breath test was carried out.

RESULTS

If endoscopy had not been performed in Helicobacter pylori patients based on 13C-urea breath test, <45 years, without alarm symptoms, and without non-steroidal anti-inflammatory drug use, 15% of endoscopies would have been saved, and one gastric ulcer and two oesophagitis would have been missed. Based on Helicobacter pylori IgG serology, 21% of endoscopies would have been saved. Finally, if endoscopy had been performed only in CagA+ patients, 31% of endoscopies would have been saved, missing one gastric ulcer and two cases of oesophagitis.

CONCLUSIONS

In our geographical area, the test-and-scope strategy based on 13C-urea breath test or Helicobacter pylori IgG serology would have saved only 15-20% of endoscopies. Although some relevant pathology would have been missed, it is not of a malignant type. 13C-urea breath test is the preferred non-invasive method to be used in this strategy, while Helicobacter pylori IgG serology is of limited value due to its low accuracy. With the use of CagA serology a larger number of unnecessary endoscopic examinations can be avoided.

What have we learned from recent dyspepsia trials?

Dyspepsia is a common disorder and a frequent complaint of patients presenting for primary care. Understanding of the role of Helicobacter pylori has led to re-evaluation of management strategies for these patients. This article highlights results from clinical trials that have helped to clarify the role of empiric therapy, endoscopy, radiography, and H. pylori eradication in patients with nonulcer dyspepsia.

Treatment of uninvestigated dyspepsia with cisapride for patients with negative Helicobacter pylori serologies

OBJECTIVE

The aim of this study was to compare symptoms for patients with uninvestigated dyspepsia and a negative Helicobacter pylori serology who were treated with cisapride or placebo.

METHODS

Helicobacter pylori-seronegative patients with chronic dyspepsia were randomized to receive cisapride 10 mg t.i.d. or placebo t.i.d. for 30 days. Symptom scores were performed 1 month and 3 months after randomization. Outcomes measured were dyspepsia symptom scores and a treatment "success" variable defined as absence of symptoms or decrease in the most severe individual symptom by two grades.

RESULTS

A total of 60 patients were randomized; 56 completed the 1-month follow-up and 40 completed the 3-month follow-up interview. The mean score for all patients at the time of entry was 11.0 and declined to 8.3 and 8.2 at 1 and 3 months, respectively, after randomization. At 1 month and 3 months after randomization, there was no significant difference in the number of patients meeting the "success" variable for patients receiving cisapride as compared to placebo. The mean decline in symptom severity scores was not significantly different for patients receiving placebo or cisapride at 1 month (mean, -2.8 vs -3.1; difference = 0.3, p = 0.74) or 3 months (-3.1 vs -2.6, difference = -0.5, p = 0.58) after randomization.

CONCLUSIONS

No significant difference in the severity of dyspeptic symptoms was found for patients receiving cisapride as compared to placebo in the setting of uninvestigated dyspepsia and a negative Helicobacter pylori serology.

Concordance between noninvasive tests in detecting Helicobacter pylori and potential use of serology for monitoring eradication in gastric ulcer

Our aim was to determine concordance between 13C-urea breath test and serology in detecting Helicobacter pylori and to study their potential use for monitoring eradication in patients with gastric ulcer. We prospectively studied 73 gastric ulcer patients. On endoscopy, biopsies were taken for hematoxylineosin staining and rapid urease testing. Blood samples were drawn for immunoglobulin G antibody determination by enzyme-linked immunosorbent assay (ELISA). A 13C-urea breath test was performed as well. Histology, serology, and urea breath tests were all repeated 1, 6, and 12 months after therapy completion in 56 infected patients. A proportion of positive agreement between serology and breath test results as high as 0.95 was found. McNemar statistic was 3 (p = 0.08), whereas kappa statistic was 0.83 (p < 0.0001). At month 6, significant differences in patients successfully treated relative to baseline serologic values were observed (chi2 = 11.7; p < 0.001). The area under the receiver operating characteristic (ROC) curve for diagnostic efficiency was 0.76, sensitivity was 74%, and specificity was 90% (for H. pylori eradication) when the fall of at least one category in serologic levels was considered as cut-off point. No further decreases in serologic levels were noted over the next 6 months, and 48.8% of patients remained seropositive 1 year after completion of successful treatment. A high concordance between serology and 13C-urea breath test results is observed when the two procedures are used for H. pylori infection diagnosis in patients with gastric ulcer. Also, serology can be successfully used for monitoring H. pylori eradication 6 months after therapy completion.

Gastric cancer and other endoscopic diagnoses in patients with benign dyspepsia

BACKGROUND

It has been suggested that endoscopy could be replaced with non-invasive assessment of helicobacter status in the initial work up of young dyspeptic patients without sinister symptoms.

AIMS

To determine the incidence of gastro-oesophageal malignancy in young dyspeptic patients.

METHODS

The Alberta Endoscopy Project captured clinical and demographic data on all endoscopies performed from April 1993 to February 1996 at four major adult hospitals in Alberta. The endoscopic and histological diagnosis in a subgroup of patients under 45 years of age without alarm symptoms that had undergone gastroscopy was reviewed. In addition, a random list of 200 patients was generated and their medical records reviewed in order to assess the proportion with symptoms suitable for a non-invasive management strategy.

RESULTS

Gastroscopy was performed in 7004 patients under 45 years. In 3634 patients (56% female) alarm type symptoms were absent; 78.9% of patients had symptoms amenable to a non-invasive initial approach, giving a corrected sample size of 2867 patients (correction factor 0.789). Three gastric cancers, one case of moderate dysplasia, 10 biopsy proved cases of Barrett's oesophagus, and 19 oesophageal strictures/rings were detected within this sample. The corrected prevalence of gastric cancer in this select population was 1.05 per thousand patients.

DISCUSSION

Endoscopy yielded three gastric cancers in this sample of under 45 year old dyspeptic patients without sinister symptoms. While initial non-invasive screening with one-week triple therapy for helicobacter positive individuals is unlikely to have a detrimental outcome the physician is advised to consider endoscopy in patients with persisting, recurrent, or sinister symptoms.

The usefulness of the likelihood ratio in the diagnosis of dyspepsia and gastroesophageal reflux disease

Clinicians are familiar with the concepts of sensitivity and specificity to describe the accuracy of a diagnostic test. These measures do not always express the probability that a patient has a disease with a given test result as this will vary with the prevalence of the disorder in the population. The likelihood ratio is a more clinically relevant method of reporting accuracy, and the probability of having a disease after a positive or negative test can be calculated. The likelihood ratio can be applied to the clinical problem of dyspepsia management. This suggests that Helicobacter pylori (H. pylori) test and treat will detect and treat most peptic ulcers with only 0.5% of H. pylori-negative patients having peptic ulcer disease. Serology is possibly acceptable in populations with an H. pylori prevalence of approximately 50%. The urea breath tests are more appropriate in more extreme prevalence ranges. Once the prevalence of H. pylori falls below 10%, then the urea breath test becomes inaccurate, and screening and treatment may be less appropriate. The absolute probability of having peptic ulcer disease in a largely H. pylori-negative population will be very small, however, and the appropriateness of performing any investigation in these circumstances is debatable. Finally, likelihood ratios indicate that the clinical diagnosis of gastroesophageal reflux disease (GERD) is not straightforward. Traditionally, it is believed that patients with dominant heartburn are likely to have GERD. Likelihood ratios predict, however, that patients with these symptoms have a little over 50% chance of having GERD as defined by 24-h esophageal pH studies.

Serologic detection of CagA positive Helicobacter pylori strains predicts the presence of peptic ulcer in young dyspeptic patients

BACKGROUND

Helicobacter Pylori infection has been strongly associated with upper gastrointestinal (GI) disease, especially duodenal ulcer. Endoscopy or contrast radiography is needed to diagnose and appropriately manage peptic ulcer disease. These diagnostic procedures, however, are time consuming and expensive; endoscopy is invasive and contrast radiography cannot help in the diagnosis of H pylori infection. Our aim was to examine in a prospective study the relation between serologic detection of cytotoxic associated gene (CagA) H pylori strains and endoscopic findings among young dyspeptic patients to determine whether this noninvasive test can help differentiate patients with from those without ulcers.

METHODS

One hundred patients younger than 45 years with dyspepsia referred for upper GI endoscopy were included in the study. During endoscopy antral biopsy specimens were obtained for the rapid urease test and histologic examination. At histologic examination gastritis was graded from 0 (normal histologic features) to 3 (severe gastritis). After endoscopy blood was obtained for serologic determination of CagA status.

RESULTS

Among the 100 patients 56 were H pylori positive and 44 were H pylori negative. In the group of 56 H pylori-positive patients 36 (64.3%) had peptic ulcers and 20 (35.7%) did not. Among patients with peptic ulcer 34 of 36 (94.4%) were CagA positive and 2 (5.6%) were CagA negative. The respective values for the group of patients without ulcers were 9 of 20 (45%) and 11 of 20 (55%). The difference in the proportion of CagA-positive subjects between the group with and that without peptic ulcer was highly significant (p < 0.0001).

CONCLUSIONS

Among young patients with dyspepsia, CagA seropositivity is highly associated with duodenal ulcer at endoscopy.

Serologic screening before endoscopy: the value of Helicobacter pylori serology, serum recognition of the CagA and VacA proteins, and serum pepsinogen I

BACKGROUND

We wanted to assess the diagnostic value of pre-endoscopy screening by Helicobacter pylori serology, serum recognition of the CagA and VacA proteins, and serum pepsinogen I levels (sPGI) in patients up to 55 years of age with uncomplicated simple dyspepsia.

METHODS

Consecutive dyspeptic patients referred for open-access endoscopy, excluding patients with alarm symptoms, recent intake of acid suppressants, or ingestion of non-steroidal anti-inflammatory drugs. H. pylori status was determined by histology and urease testing. H. pylori serologic status was determined with the enzyme-linked immunosorbent assay (ELISA) and Western blotting, serum recognition of CagA and VacA with Western blot, and sPGI levels by radioimmunoassay.

RESULTS

One hundred and fifteen patients were studied (mean age, 40 years: range, 20-55 years), of whom 58 were H. pylori-positive in biopsy-based tests. Twenty-one patients (18%) had significant gastroduodenal lesions (erosions, ulcers, or cancer). The sensitivity (specificity) of the ELISA (optimized) and Western blot in determining H. pylori status was 94.8% (89.5%) and 100% (96.4%), respectively. Screening strategies based on the ELISA or Western blot for determining H. pylori serologic status would have detected 95% or 100% of significant lesions, respectively, and each 'saved' 47% of endoscopies for simple dyspepsia. Serum recognition of the CagA protein would have detected 95% of significant lesions and 'saved' 55% of endoscopies, whereas recognition of the VacA protein would have detected only 81% of the lesions. Screening by H. pylori serology plus a 'low' (<55 ng/ml) or 'high' sPGI (>125 ng/ml) would detect only 57% of significant lesions, although the only case of cancer was included in the hypopepsinogenaemic subgroup of just 11 patients.

CONCLUSIONS

In patients with uncomplicated, simple dyspepsia up to 55 years of age, screening by H. pylori serology identified 95%-100% of patients with significant gastroduodenal lesions while potentially saving 46.9% of endoscopies. Serum recognition of the CagA protein identified 95% of lesions and would have saved an additional number of endoscopies (7.9%) compared with basic serology. Measurement of sPGI was of limited diagnostic value.

How should Helicobacter pylori positive dyspeptic patients be managed?

Dyspepsia, according to the internationally accepted Rome criteria, refers to pain or discomfort centred in the upper abdomen; patients with predominant heartburn are excluded from this group, although minor or infrequent heartburn is commonly associated with dyspepsia. It is an important condition not only because it is common and costly, but because it may indicate the presence of serious disease such as peptic ulcer or gastric cancer. However, the most frequent causes of dyspepsia are functional dyspepsia and gastro-oesophageal reflux disease. The discovery of Helicobacter pylori has resulted in important advances in the management of dyspepsia. The clinician faced with a patient who has persistent or recurrent dyspepsia needs to differentiate clearly those patients who have not been previously investigated from patients documented to have functional dyspepsia after investigation (fig 1). Here, the management of H pylori positive dyspeptic patients who have and have not been fully investigated will be reviewed.

Chronic recurrent abdominal pain

Chronic recurrent abdominal pain remains a common medical and surgical problem, frequently dismissed as functional. Instead, these patients should be approached systematically, based on the pattern of recurrent abdominal pain. It is vital to seek out the potential cause of this type of chronic pain because specific and often curative treatment is available.

How should new-onset dyspepsia be managed in general and specialist practice?

Managing patients with new-onset dyspeptic symptoms represents a real challenge in clinical decision-making. The major controversy has been over the optimal management strategy of patients with new-onset dyspeptic symptoms who do not present with alarm symptoms. Since unaided clinical diagnosis is unreliable, proposed management strategies have included empirical treatment algorithms, computer-assisted predictive score models and Helicobacter pylori-based strategies such as test-and-scope or test-and-treat algorithms. Endoscopy remains the diagnostic 'gold standard', and the management should ideally be based on endoscopic diagnosis. Because of economic constraints and increasing waiting lists, this is not possible. When precise and comprehensive guidelines have been formulated, future patients will probably be managed in primary care by a Helicobacter test-and-treat policy, leaving only empirical treatment failures for specialist evaluation.

[Helicobacter eradication: an expensive Sisyphus task]

BACKGROUND

The benefits of eradicating H. pylori infection vary about the antimicrobial regimen. In contrast, comparing many clinical studies the overall outcomes seem independent of the kind of treatment. Therapy depends on accurate diagnosis. Therefore, the observed differences and correspondences can be caused by not obviously but systematic influences using noninvasive diagnostic tests.

METHOD

Simulations concerning noninvasive tests with variable specificity and sensitivity were performed. The results were compared to the hypothetical estimate that 1/3 of the population of Germany were H. pylori infected. This group should be traced and checked again after a treatment with 90% efficacy.

RESULTS

In comparison to the a priori conditions most decisions according to noninvasive tests were not valid. Both sensitivity and specificity differ significantly from 100%, therefore the accuracy was low. The differences between true positives and true negatives were unpredictably accelerated if the inclusion criteria depend on the poor sensitivity of the first test. For the second test which is commonly used regarding its specificity, there is a change in the statistical behavior. As a result, the homogeneity that is true and false negatives and positives of the non-infected or infected groups differed considerably. One of the examples was a procedure using a test with 79% specificity and 85% sensitivity. If the prevalence of the infection was 33% the simulations demonstrated a therapeutic effect of about 76.5% instead of a priori efficacy of 90%. Under these conditions 14% of the population become false positive. Furthermore, the simulations revealed a second effect. Using the same test with low accuracy twice the investigator got the impression of superior therapeutic considerations. The misleading conclusion was caused by diminished sensitivity if the specificity remained constant. Thus, neither serological tests nor the 13C-breathtests can be assumed as validated methods for both to screen infected people and to check the treatment. Furthermore, the noninvasive tests are not useful for the determination of the prevalence of H. pylori infection. The influence of variable sensitivity and specificity of a diagnostic test on the outcome of a clinical trial can become a bias or can be used to manipulate the outcome.

CONCLUSION

The effect of a therapeutic regimen depends on the prevalence of the H. pylori infection. Because it is difficult to separate true positives, in clinical trials the main effects and interactions can be improved under the conditions used in "experimental design". Some earlier results must be reevaluated because of the bias resulting from inadequate diagnostic tests.

Blood tests in the management of Helicobacter pylori infection. Italian Helicobacter pylori Study Group

There are three main types of blood test available for the management of Helicobacter pylori infection: those that detect an antibody response; tests of the pathophysiological state of the stomach; and those that indicate an active infection. Enzyme linked immunosorbent assay (ELISA) based kits are the most numerous of the commercially available tests. Originally the kits used crude antigen preparations but many of the newer kits use a more purified antigen preparation giving increased specificity but a lower sensitivity. The sensitivity, specificity, and predictive values of the tests can also be affected by the population under test and coexistent disease in the patients. Near patient test kits are based on either latex agglutination or immunochromatography. Generally, they have low sensitivities compared with laboratory tests. Commercial western blotting kits have also been developed and are used to detect the presence of specific virulence markers. The exact role of serology in the management of Helicobacter infection has still to be defined, although there is evidence that, used as a screening procedure, it can reduce endoscopy cost and workload. Gastrin and pepsinogen blood concentrations may provide valuable information on the pathophysiological state of the stomach--for example, the presence of inflammation or gastric atrophy. A combination of serology and serum concentrations of gastrin and pepsinogen may be used effectively to detect serious gastroduodenal disease in patients.

Screening for Helicobacter pylori in young dyspeptic patients referred for investigation--endoscopy for those who test negative

BACKGROUND

Studies in young dyspeptic patients have suggested that screening strategies based on non-invasive H. pylori testing can reduce endoscopy workload by 25-40%. Such strategies usually propose that only H. pylori-positive individuals should undergo endoscopy. This approach may fail to diagnose idiopathic ulcers, ulcers in patients whose screening test is falsely negative and reflux disease.

AIM

To investigate a hypothetical screening strategy in which endoscopy is initially performed only in H. pylori-negative dyspeptics.

METHODS

Seventy-two consecutive patients under 45 years of age undergoing investigation for 'ulcer-like' dyspepsia had invasive and non-invasive determination of H. pylori status. Individuals found to be H. pylori-positive at endoscopy received 1 week of proton pump inhibitor-based triple therapy. H. pylori-negative individuals received therapy tailored to their diagnosis. Endoscopy was repeated in the positive group to confirm successful eradication. Results were analysed according to our strategy, i.e. serologically-positive patients would have received eradication therapy without endoscopy, but patients found to be negative would have been referred for endoscopy.

RESULTS

According to the serology test there were 39 positive and 33 negative results. Symptoms failed to resolve during follow-up in nine of the serological positives despite successful eradication. There were also five false positives who were deemed likely treatment failures. Thus according to our strategy, these 14 serologically-positive patients would ultimately have required an endoscopy and the other 25 serologically-positive patients would have avoided an endoscopy, resulting in a 35% reduction in endoscopy usage in this population. In the serologically-negative group there were three cases of peptic ulcer disease where the test was falsely negative, but they were detected by the strategy. No cases of gastric malignancy were detected at endoscopy. Thus our strategy would have reduced initial endoscopy referrals by 35% in this selected population.

CONCLUSION

A strategy of empirical H. pylori eradication therapy can safely reduce the requirement for endoscopy in young dyspeptic patients without sinister symptoms.

Testing for Helicobacter pylori in primary care: trouble in store?

STUDY OBJECTIVE

To assess the role of testing for Helicobacter pylori in the management of dyspeptic patients in primary care.

DESIGN

Selective review of literature frequently quoted to support use of H pylori testing.

MAIN RESULTS

Testing for H pylori and referral of only positive cases for endoscopy aims to reduce the number of "unnecessary" endoscopies. Patients with negative results may receive short-term reassurance and subsequently place fewer demands on health services. However, studies to date have only assessed this practice in secondary care settings. Given the relatively high prevalence of both dyspepsia and H pylori infection, the transfer of this practice to primary care may lead to a paradoxical increase in endoscopy referrals. Identification of H pylori and prescribing of eradication treatment also aims to reduce endoscopy referrals. No primary care trials have yet assessed this approach. Given that fewer than one in four of dyspeptic patients have peptic ulceration, a high proportion may fail to respond to eradication treatment and subsequently require referral for endoscopy. The longer term clinical and psychosocial sequelae of treating or labelling patients with an infection associated with gastric cancer remain unknown.

CONCLUSIONS

Given uncertainty concerning the possible adverse effects of H pylori testing in primary care, we suggest a moratorium on its use in this setting until results from relevant clinical trials become available.

Relation between Helicobacter pylori infection and gastrointestinal symptoms and syndromes

BACKGROUND

Helicobacter pylori is a human pathogen that colonises the gastric mucosa and causes permanent gastric inflammation.

AIMS

To assess the symptoms of H pylori infection in an adult unselected population.

SUBJECTS

A random sample of 3589 adult Danes who were examined in 1982 and 1987 (n = 2987).

METHODS

Abdominal symptoms within the preceding year were recorded at both attendances. Circulating IgG antibodies against H pylori in serum samples drawn in 1982 were measured by using in-house indirect enzyme linked immunosorbent assays (ELISA).

RESULTS

People with increased levels of IgG antibodies to H pylori were more likely than uninfected individuals to report heartburn (odds ratio (OR) = 1.26, 95% confidence interval (CI) 1.03-1.54) and abdominal pain characterised by daily length (OR = 1.33, 95% CI 0.92-1.91), nocturnal occurrence (OR = 1.62, 95% CI 1.19-2.19), spring aggravation (OR = 1.68, 95% CI 0.70-4.05), and no relation to meals (OR = 0.62, 95% CI 0.43-0.91) or stress (OR = 0.69, 95% CI 0.50-0.95). The inclusion of people with increased levels of IgG antibodies to H pylori, but without upper dyspepsia, at study entry significantly increased the likelihood of reporting upper dyspepsia at follow up (OR = 1.71, 95% CI 1.24-2.36). People with epigastric pain and increased levels of IgM antibodies to H pylori only indicative of acute H pylori infection were more likely to report nocturnal pain, heartburn, nausea, and vomiting.

CONCLUSION

H pylori infection may precede the development of dyspepsia and is associated with a variety of gastrointestinal symptoms in people with no history of peptic ulcer disease.

Comparison of serum, salivary, and rapid whole blood diagnostic tests for Helicobacter pylori and their validation against endoscopy based tests

BACKGROUND

A rapid, reliable, and accurate test for the diagnosis of infection with Helicobacter pylori is needed for screening dyspeptic patients before referral for endoscopy.

AIM

To compare a new rapid whole blood test (Helisal rapid blood, Cortecs), two serum enzyme linked immunosorbent assays (ELISAs; Helico-G, Shield and Helisal serum, Cortecs), and a salivary assay (Helisal saliva, Cortecs), with slide biopsy urease, 13C-urea breath test, and histology.

METHODS

Three hundred and three consecutive dyspeptic patients attending for gastroscopy underwent two antral biopsies for histology, and one for rapid slide biopsy urease test for assessment of H pylori status. Blood and saliva were also collected. One hundred of the patients also underwent a 13C-urea breath test. Gold standard positives were defined as those with at least two positive tests among slide urease, breath test, or histology, and gold standard negatives as those with all these (or two when the breath test was not done) negative.

RESULTS

Of 300 patients (median age 63, range 28-89) eligible for analysis, 137 (46%) were gold standard positives, of which Helisal rapid blood identified 116, Helico-G 129, Helisal serum 130, and Helisal saliva 120; 137 (46%) were gold standard negatives of which the number falsely identified as positive was 30 by Helisal rapid blood, 45 by Helico-G, 41 by Helisal serum, and 41 by Helisal saliva. Sensitivities and specificities were: for the whole blood test 85% and 78% respectively; for Helico-G 94% and 67%, for Helisal serum 95% and 70%, and for Helisal saliva 84% and 70%.

CONCLUSIONS

If endoscopy had been undertaken only on patients with positive tests two of 16 duodenal ulcers would have been missed if the Helisal rapid blood test was used, and one if any of the ELISA tests were used. None of the blood tests would have missed any of six gastric ulcers, but the salivary test would have missed one.

Predicting endoscopic diagnosis in the dyspeptic patient. The value of predictive score models

BACKGROUND

Score models to predict endoscopic diagnosis in dyspepsia may compensate for the unreliable clinical diagnosis. This study aimed to construct and test score models designed to predict diagnosis in dyspepstic patients managed in primary care.

METHODS

Three models to predict organic dyspepsia, major dyspepsia, or peptic ulcer were constructed by regression analysis of clinical data from 1026 consecutive dyspeptic patients referred for endoscopy. The models were tested in 207 patients in primary care, who were potential candidates for endoscopy. Validation experiments were analysed using receiver operating characteristic (ROC) curves.

RESULTS

Significant losses of predictive power were found for all models when applied to primary care patients, and no model could be used as a reliable decision support instrument in primary care.

CONCLUSIONS

Predictive score models developed in patients referred for endoscopy are not reliable when applied to patients in primary care who are potential candidates for endoscopy. Future models should be constructed and validated in unselected primary care populations.

Serodiagnosis of Helicobacter pylori infection: comparison and correlation between enzyme-linked immunosorbent assay and rapid serological test results

CLOser is a new, one-step, qualitative anti-Helicobacter pylori immunoglobulin G test having the advantage of convenience and simplicity. We aimed to evaluate its diagnostic accuracy and to compare it with a quantitative enzyme-linked immunosorbent assay (ELISA) (HEL-pTEST II) in a study of 86 adult dyspeptic patients by using the results from histology and urease testing of gastric biopsies as a "gold standard." Forty-six patients were H. pylori positive. The sensitivities, specificities, and positive and negative predictive values were 95.7, 72.5, 80.0, and 93.5%, respectively, for CLOser and 93.5, 92.5, 93.5, and 92.5%, respectively, for HEL-pTEST II. The grade of the colored test bands in CLOser was correlated with antibody titers in HEL-pTEST II (r = 0.71; p < 0.001). The mean antibody titers were 13, 74, 186, and 328 U/ml for the negative, faint, thin, and thick bands, respectively, of CLOser. We concluded that the CLOser rapid serological test yielded sensitivity similar to that of the conventional ELISA. Although CLOser is not suitable for epidemiologic screening for H. pylori infection on account of lower specificity, it is particularly convenient and very easy to perform. Therefore, it may eventually become widely used in the office-based care of patients and lead to more cost-effective patient management decisions.

Prospective screening of dyspeptic patients by Helicobacter pylori serology

Helicobacter pylori infection is associated with 95% of duodenal ulcers and more than 80% of gastric ulcers. Several reports have indicated that screening for H pylori may avoid subsequent endoscopic examination. We screened 183 dyspeptic patients, aged under 45, by taking a history of sinister symptoms and regular use of non-steroidal anti-inflammatory drugs (NSAIDs), together with serological testing for H pylori. Endoscopy was performed on 113 patients, of whom 90 (49%) were seropositive, 14 (8%) had sinister symptoms, and 9 (5%) had used NSAIDs regularly. In 34 (19%) patients we detected peptic ulceration. The remaining 70 (38%) patients who were H pylori seronegative, had no sinister symptoms, and had not taken NSAIDs (screen-negative), did not undergo endoscopy but were returned to their primary care physician for treatment of symptoms. At subsequent reassessment (of the non-endoscoped group), symptom severity (p = 0.002), interference with life events (p = 0.01), and medication (p = 0.0002) were all significantly lower in the 6 months after screening than in the 6 month period before screening. Only three screen-negative patients were re-referred after screening but their endoscopic findings were normal. Thus, 67 (36%) endoscopies were avoided. When the non-endoscoped screen-negative patients were compared with a cohort of endoscoped screen-negative patients, the groups did not differ in terms of symptom severity (odds ratio 1.12, 95% CI 0.53-2.35, p = 0.77) or interference with life events (0.82, 0.38-1.76, p-0.61). However, medication use was significantly less (0.37, 0.17-0.80, p = 0.01) in those who did not have an endoscopy. Our study indicates that colonisation screening based on H pylori serology, a history of sinister symptoms, or a history of NSAID use was worthwhile in dyspeptic patients. We avoided 37% of endoscopies and reduced drug usage without disadvantaging those not endoscoped.