Characteristics of Helicobacter pylori infection in Jamaican adults with gastrointestinal symptoms

Helicobacter pylori infection is common in Jamaica. Describing its epidemiology in a population-based study depends largely on serology, but serologic assays have not been validated in this population. To address this issue, we examined the presence of H. pylori infection in 30 sequential adult patients with gastroduodenal symptoms by three biopsy-based methods (rapid urease test, histology, and culture) as well as by one research and two commercial enzyme-linked immunosorbent assays (ELISAs). A patient was considered H. pylori positive if the organism was detected by at least one biopsy-based method. Eighteen (60%) of the 30 patients were H. pylori positive by these criteria, whereas 21 (70%) were seropositive for H. pylori immunoglobulin G by our research ELISA. The presence of H. pylori infection in patients with gastric cancer and those with chronic gastritis was missed by biopsy-based methods but was detected by serologic assays. This observation indicates that serologic assays may be better suited for the detection of this infection in a population in which H. pylori-associated pathology is prevalent. The performance of our research ELISA in detecting biopsy-based H. pylori-positive cases was excellent, with a sensitivity and specificity of 100% and 75%, respectively. Molecular genotyping of the isolates revealed that the predominant H. pylori genotypes in this cohort of Jamaicans were cagA(+) vacA slb-m1, and iceA2. The validated serologic assay enables us to interpret epidemiologic data from population-based studies in Jamaica by comparison to those from other populations.

Admixture with whole blood does not explain false-negative urease tests

Rapid urease test sensitivity for Helicobacter pylori is reduced in the presence of active upper gastrointestinal bleeding. The aim of this study was to evaluate the in vitro effect of whole blood on rapid urease testing. Urease solution was added to normal saline, and heparinized whole blood both positive and negative for H. pylori antibody. The mixtures were then serially diluted in saline, and/or whole blood and added to three different rapid urease kits. The admixture of urease in H. pylori-seropositive whole blood diluted in either saline or whole blood enhanced performance in both kits fourfold compared with saline alone. No false-negative results were observed in either kit. Seronegative whole blood produced similar results. Undiluted saline or whole blood produced no positive rapid urease tests. Whole blood accelerates the urease reaction in vitro. Neither H. pylori antibody-positive nor -negative whole blood adversely impacted the rapid urease test. False-negative rapid urease test results in upper gastrointestinal bleeding cannot be explained by admixture with whole blood.

Fifteen years later: colonoscopic retroflexion revisited

OBJECTIVE

Retroflex views of the rectal vault are included in the teaching of colonoscopic technique but are not pervasive in clinical practice. The utility of adding a retroflex maneuver at the end of colonoscopy has yet to be determined. The aim of this study was to evaluate the additional benefit of a retroflex view of the rectal vault at the completion of colonoscopic examination.

METHODS

A prospective study of consecutive colonoscopies performed by a single physician was conducted. The rectal vault was first visually inspected upon withdrawal of the colonoscope. The endoscope was then readvanced into the rectum and retroflexed to view the vault. Endoscopic findings on both views were recorded along with demographic patient information. The six groups of findings sought on the two views were: retained stool, abnormal hemorrhoids, erosions/ulcerations, polyps, masses, and normal examinations. A determination on whether retroflex views influenced patient diagnosis was recorded by the endoscopist.

RESULTS

There were 453 patients enrolled: 182 (40.2%) male and 271 (59.8%) female, consisting of 216 African-Americans, 232 Caucasians, and five Asians. The retroflex maneuver was performed successfully in 445 of 453 patients. In all but nine cases, the retroflex view did not produce additional information. The nine findings included three inflammatory pseudopolyps, five hyperplastic polyps, and one case of erosions/ulcerations.

CONCLUSIONS

In the majority of cases, retroflexing the endoscope does not produce additional information compared with the thorough examination in straight view. The retroflex view may be of benefit if there is suspicion of pathology upon insertion or withdrawal of the colonoscope.

Comparison of [13C]urea blood test to [13C]urea breath test for the diagnosis of Helicobacter pylori

OBJECTIVE

It has been determined that the [13C]urea breath test (UBT) is a safe and effective way of detecting Helicobacter pylori (H. pylori) infection. Some individuals may have difficulty performing the exhalation component of the test, possibly due to age, or mental or physical compromise. Our aim was to determine if a commercially developed [13C]urea blood test could be utilized as a substitute for the UBT to detect H. pylori infection.

METHODS

Patients who were referred by their physicians for UBT were offered study inclusion. Patients underwent baseline and 30-min UBT. A simultaneous blood sample of 3 cc was drawn into a heparinized vacutainer at the 30-min period of the UBT. [13C]urea levels in both blood and breath samples were analyzed using isotope ratio mass spectrometry. UBT > or = 6 delta per mil over baseline and urea blood tests > (-17 delta per mil) were considered positive.

RESULTS

One hundred sixty-one patients (68 men/93 women) with average age of 47.0 +/- 14.2 yr were tested. Agreement between breath and blood test results occurred in 153/161 (95%) cases. Using the UBT as the diagnostic standard, the urea blood test resulted in 44 true positive, 109 true negative, four false positive, and four false negative results, giving a sensitivity of 92%, specificity of 96%, positive predictive value of 92%, and negative predictive value of 96%.

CONCLUSIONS

The urea blood test was found to be comparable to the urea breath test in the detection of H. pylori infection. The urea blood test will be accurate in the diagnosis of active H. pylori infection.

Helicobacter pylori and gastric cancer

Infection with Helicobacter pylori is now recognized as the primary cause of peptic ulcers and their recurrence. Compelling evidence has also been found linking H. pylori infection to gastric cancer, the second most common cancer in the world. Given the high rate of patient morbidity and mortality associated with gastric cancer, any method by which one can reduce the occurrence of the disease or increase its early detection is desirable. The strong correlation with H. pylori infection and the current availability of easily administered tests for the detection of the pathogen argue for screening at least those individuals with a family history of gastric cancer or other risk factors. This article reviews the association between H. pylori and gastric cancer and the pathologic changes that the infection produces in the gastric mucosa, as well as the cost-effectiveness of universal testing and eradication of the infection in H. pylori-positive individuals to reduce gastric cancer.

Evaluation of the FlexSure HP whole blood antibody test for diagnosis of Helicobacter pylori infection

OBJECTIVE

Rapid, inexpensive, reliable tests are needed to facilitate the diagnosis of Helicobacter pylori infection. We evaluated the accuracy of the new FlexSure HP whole blood test (SmithKline Diagnostics, Inc.), a rapid, qualitative in-office test for the detection of antibodies to H. pylori utilizing whole blood obtained from a fingerstick.

METHODS

Five North American sites enrolled patients not previously treated for H. pylori who underwent upper endoscopy. Patients had not received antibiotics, bismuth, or proton pump inhibitors within 4 wk before study enrollment. Bacterial infection was established by the presence of H. pylori in gastric biopsies (minimum of two) or positive rapid urease test of antral tissue. The presence of IgG antibodies was determined using FlexSure HP whole blood tests with blood obtained by fingerstick and FlexSure HP serum and ELISA (HM-CAP) tests with serum obtained from venipuncture.

RESULTS

Three hundred ninety-three patients were enrolled (56% male; mean age, 46.8 +/- 16.0 yr). H. pylori infection was present in 187 (48%). Compared with the standard of histology and rapid urease test, sensitivity for FlexSure HP whole blood, FlexSure HP serum, and HM-CAP EIA were, respectively, 84%, 90%, and 95% (p < 0.05 compared with FlexSure HP whole blood). There were no statistical differences in specificity or overall accuracy between the three tests.

CONCLUSIONS

FlexSure HP whole blood demonstrated an accuracy not significantly different from the FlexSure HP serum test but had sensitivity significantly lower than the HM-CAP EIA. FlexSure HP whole blood may be useful for in-office H. pylori diagnosis.

Effect of standard and high dose ranitidine on [13C]urea breath test results

OBJECTIVE

It has been suggested that standard dose H2 blockers will affect the [14-C]urea breath test. The aim of this study was to evaluate the effect of standard and high dose ranitidine on the [13C]urea breath test in a prospective cross-over study.

METHODS

Volunteers found to be positive for H. pylori by IgG serology and [13C]urea breath test were given either ranitidine 150 mg b.i.d. or 300 mg b.i.d. for 14 days. Repeat breath tests were completed on the last day of antisecretory dosing and study patients were immediately crossed over to the other ranitidine dose. The third breath test was performed at 14 days after initiation of the new dose.

RESULTS

A total of 20 volunteers were enrolled. Using the established cut-off of 2.4% for the commercial breath test, only one patient developed negative results on H2 blockers. This patient had negative breath tests on both ranitidine doses and remained test-negative off all medications 6 wk after study completion, suggesting either a false positive baseline test or an unexpected bacterial eradication. No specific trend in breath test results was observed for the group (p=NS). On ranitidine 300 mg, six of 19 patients elevated their breath results from 23% to 112% (mean 76%) above baseline.

CONCLUSION

Ranitidine at standard or high doses did not generate a reproducible decline in breath test results. Histamine 2 blockers do not need to be discontinued before urea breath testing.

Four-year trends in Helicobacter pylori IgG serology following successful eradication

PURPOSE

Detection of anti-Helicobacter pylori antibodies is accurate in the diagnosis of the infection, and there is a decline in IgG titers after successful eradication. It is not known whether these titers continue to decline during the next 3 to 4 years.

PATIENTS AND METHODS

Patients had been successfully treated for H pylori with triple therapy (metronidazole, tetracycline, and bismuth subsalicylate) during 1990 and 1991. Those who had frozen serum samples available from that time were contacted to have follow-up serum collected in 1994. A simultaneous [13C]urea breath test was done to confirm H pylori infection status. Serology was determined by quantitative enzyme-linked immunosorbent assay (ELISA) and qualitative immunoassay.

RESULTS

All 29 patients who agreed to participate were free of H pylori infection. They had a mean decrease in H pylori IgG titers of 51% from baseline (P <0.001). Titers remained stable from 1 year to a mean of 3.5 years after therapy (range 2.8 to 4.4). Of the 29 patients, 21 (72%) remained seropositive by ELISA 3.5 years after successful H pylori treatment, and 18 (62%) remained positive by rapid serum immunoassay.

CONCLUSION

IgG titers against H pylori plateau at a 50% decrease after therapy. Helicobacter pylori serology, either quantitative or qualitative, will yield false positive results in patients who have previously been treated for H pylori and should not be used to determine infection status in this population.

Cost savings in duodenal ulcer therapy through Helicobacter pylori eradication compared with conventional therapies: results of a randomized, double-blind, multicenter trial. Gastrointestinal Utilization Trial Study Group

BACKGROUND

We hypothesized that treatment of duodenal ulcer disease with antibiotic therapy directed toward Helicobacter pylori infection is more cost-effective than therapy with antisecretory agents.

METHODS

A randomized, double-blind, multicenter clinical trial of adult patients with active duodenal ulcer and H. pylori infection was conducted. Patients were randomized to receive 500 mg of clarithromycin 3 times a day plus 40 mg of omeprazole daily for 14 days followed by 20 mg of omeprazole daily for an additional 14 days (group 1), 20 mg of omeprazole daily for 28 days (group 2), or 150 mg of ranitidine hydrochloride twice a day for 28 days (group 3). The use of ulcer-related health care resources was documented during monthly interviews for 1 year after the initial therapy. Clinical success was evaluated 4 to 6 weeks and 1 year after the end of therapy.

RESULTS

Of the 819 patients enrolled, 727 completed the study. Group 1 included 243 patients; group 2, 248 patients; and group 3, 236 patients. Patients in group 1 used fewer ulcer-related health care resources during the 1 year after therapy compared with groups 2 and 3 (comparisons are given as group 1 vs group 2 and group 1 vs group 3, respectively): the number of endoscopies performed, 28 vs 76 (P<.001) and vs 71 (P<.001); patients receiving drugs to treat an ulcer, 118 vs 180 (P<.001) and vs 168 (P<.001); clinic visits, 83 vs 135 (P=.05) and vs 161 (P<.001); hospitalizations, 0 vs 5 (P=.045) and vs 6 (P=.02); and length of hospital stay, 0 vs 24 days (P=.04) and vs 37 (P=.04). When ulcer-related costs were defined as the outcome variable in a multivariate linear regression analysis, therapy was determined to have a significant influence on costs (group 1 vs group 2, P<.001; group 1 vs group 3, P=.008). Clinical success rates at the end of the study and cure of H. pylori infection were significantly greater in group 1 compared with groups 2 and 3 (P<.001). Therapy with clarithromycin plus omeprazole provided savings of $1.94 and $2.96 (compared with therapy with omeprazole and with ranitidine hydrochloride, respectively) per dollar spent within the first year after therapy. This incremental cost-benefit translates to savings of $547 or $835 per patient in group 1 (compared with patients in group 2 or group 3, respectively) during the first year after therapy.

CONCLUSIONS

Combination therapy with clarithromycin and omeprazole resulted in significantly fewer uses of ulcer-related health care resources than conventional antisecretory therapy during a 1-year follow-up and significant savings in associated costs during the same period. Patients who received clarithromycin plus omeprazole also showed a significantly improved clinical outcome compared with patients who received only omeprazole or ranitidine.

Accuracy and economics of Helicobacter pylori diagnosis

Many diagnostic tests are available to establish Helicobacter pylori infection status. Most of the tests are accurate though none works perfectly, and no gold standard for diagnosis exists. Newly developed serum immunoassay kits can substitute for laboratory-based enzyme-linked immunosorbent assays, but whole blood immunoassays do not yet demonstrate adequate performance characteristics. Serologic diagnosis of H. pylori remains the most cost-effective option and should be utilized to establish initial infection in the majority of cases. If rapid urease testing is performed at endoscopy, negative results can be confirmed with a subsequent serologic test in those patients with a high probability of infection. Obtaining additional gastric tissue at endoscopy to evaluate for bacterial infection is reasonable if specimens are being taken for a mucosal defect. Confirmation of bacterial eradication cannot be justified for all post-treatment patients at present due to the expense. It is important to test for cure in those patients with complicated ulcer disease and those with recurrent symptoms after therapy.

Value of serology as a noninvasive method for evaluating the efficacy of treatment of Helicobacter pylori infection

The systemic humoral response to Helicobacter pylori was studied in 86 infected adult patients before antimicrobial therapy and at intervals following therapy. Endoscopy with collection of biopsy specimens was performed immediately before treatment; a 13C-labeled urea breath test was performed, and blood specimens were collected before treatment and at 1, 3, 6, 9, and 12 months after treatment. Serum samples from three patient groups (eradication success [n = 50], eradication failure [n = 16], and no treatment [n = 20]) were assayed for IgA and IgG antibodies to H. pylori by enzyme-linked immunosorbent assay. Levels of antibody to H. pylori before treatment were similar in all three groups. As expected, the no treatment and eradication failure groups had no significant changes in antibody levels during the study period. In contrast, for the eradication success group, the specific IgA and IgG antibody levels decreased progressively and significantly. We conclude that serology is a potentially useful way to monitor the success of treatment of H. pylori infection without using invasive or more expensive methods.

Helicobacter pylori recurrence after successful eradication: 5-year follow-up in the United States

OBJECTIVES

We previously reported a 3.4% posttreatment Helicobacter pylori recurrence rate over 18 months. We undertook to establish the rate of reinfection in our United States cohort up to 80 months after successful therapy.

METHODS

Previously studied patients who had successful triple therapy for H. pylori during 1989-92 were identified. Baseline infection had been established by the presence of H. pylori on antral biopsies as well as positive [13C]urea breath tests. Eradication of H. pylori had been confirmed by repeat endoscopy and breath test 4 wk after therapy. Three of four subjects reported that H. pylori recurrences had occurred in the first year after therapy. Patients remaining free of infection were invited back for follow-up breath test in 1995-1996.

RESULTS

One hundred fourteen patients were identified: 56 were unavailable or were using medications that would interfere with H. pylori testing. The remaining 58 patients (50.9%) included 32 M/26 F, mean age 62.9 yr. The mean follow-up period was 58 months, range 34-80 months. Positive breath tests occurred in 2/58 patients (3.4%) at 54 and 70 months after therapy. Both patients reported recurrent epigastric symptoms. The H. pylori recurrence rate for our group was 3.4% over the 4 yr since their last evaluation, or 0.85% recurrence per year. Defining recurrence as reinfection occurring after 1 yr, the total recurrence rate for the group over the 5 yr since treatment was 3/59 patients (5.1%), or 1.0% H. pylori recurrence per year posttreatment.

CONCLUSIONS

The rate of H. pylori reinfection after successful therapy is low in the United States and approximates 1% per year.

Evolving therapy for Helicobacter pylori infection: efficacy and economic impact in the treatment of patients with duodenal ulcer disease

Helicobacter pylori infection is present in most patients with duodenal ulcer disease, and cure of H pylori infection has been shown to dramatically reduce ulcer recurrence. Therapeutic strategies for duodenal ulcer disease have rapidly evolved over the past several years in an effort to consistently cure H pylori infection in a safe, cost-efficient manner. This paper reviews the effectiveness of treatments for H pylori infection in patients assessed with duodenal ulcer disease. The impact of clinical success on economic effectiveness has been determined in a recent prospective outcomes trial. Treatments with clarithromycin plus omeprazole or clarithromycin plus ranitidine-bismuth-citrate (RBC) provide consistent cure of H pylori infection, with eradication rates of 70% to 80%. Recent studies suggest that higher rates of eradication are possible with triple combination therapy (e.g., clarithromycin plus a second antibiotic and a proton pump inhibitor or RBC), but the optimal triple therapy regimen (including the combination of drugs, dosage, and duration of treatment) has not yet been defined. A recent 1-year prospective outcomes trial has demonstrated that eradication therapy with clarithromycin and omeprazole, compared with standard antisecretory therapy, provides measurable savings in utilization of ulcer-related health-care resources. Combination therapy with clarithromycin plus omeprazole, clarithromycin plus RBC, or clarithromycin plus lansoprazole and amoxicillin have been approved for the treatment of H pylori infection in patients with duodenal ulcer disease. Economic analysis has confirmed that cure of H pylori infection not only contributes to the clinical resolution of duodenal ulcer disease, but also provides economic advantages by reducing costs associated with recurrence.

Diagnostic tests for Helicobacter pylori infection

The two major catagories of diagnostic methods for Helicobacter pylori are invasive tests, or those that require endoscopy, and noninvasive, or nonendoscopic, tests. Diagnostic tests that use endoscopy include rapid urease tests, histology, and culture. Tests for which esophagogastroduodenoscopy is not necessary include various methods of antibody detection and carbon-labeled urea breath tests. Most tests are accurate, although none works perfectly and no gold standard for diagnosis exists. This article reviews the diagnostic methods available to establish H. pylori infection status and identifies some common mistakes made in testing. The costs associated with H. pylori diagnosis are evaluated and some cost-effective approaches to testing are suggested. Finally, the article offers some guidelines on choosing the appropriate diagnostic test in different clinical situations to determine the H. pylori infection status.

Evaluation of a rapid, new method for detecting serum IgG antibodies to Helicobacter pylori

There is an increased need for rapid, inexpensive tests to diagnose Helicobacter pylori infection. Our objective was to determine the performance characteristics of an immunochromatographic test (ICT) for detection of anti-H. pylori IgG antibodies. A commercially available ICT kit (FlexSure HP) was tested with a well-characterized cohort of banked sera as well as with fresh serum from randomly selected symptomatic patients. The ICT was evaluated with 107 stored sera and 96 prospective patients. The test correctly identified 65 of 68 H. pylori-infected and 37 of 39 noninfected stored sera and 54 of 57 infected and 30 of 39 noninfected patients. Sensitivity, specificity, and positive and negative predictive values were 96%, 95%, 97%, and 93% in stored serum and 95%, 77%, 86%, and 91% in fresh serum, respectively. We concluded that the ICT, reported at 4 min, is highly sensitive for detecting anti-H. pylori IgG antibodies in human serum. With a high negative predictive value, the test may be used to exclude H. pylori infection in symptomatic patients.

Quantitative noninvasive testing for Helicobacter pylori does not predict gastroduodenal ulcer disease

BACKGROUND

Helicobacter pylori is strongly associated with gastric and duodenal ulcer disease. However, the diagnosis of gastroduodenal ulcers requires an endoscopic or radiographic examination. In this study, we attempted to establish a relationship between the magnitude of [13C]urea breath test results or serum H. pylori IgG levels and endoscopic findings in H. pylori-infected individuals.

METHODS

Patients who had undergone endoscopy and had a positive [13C]urea breath test and/or positive H. pylori IgG serology were identified. Endoscopic diagnoses included duodenal ulcer, gastric ulcer, nonulcer dyspepsia, and others. Results of 6% or greater on the [13C]urea breath test was defined as positive for H. pylori infection. H. pylori IgG serology was determined by an enzyme linked immunosorbent assay with values of greater than or equal to 1.0 being seropositive.

RESULTS

One hundred seventy-five patients were seropositive (mean = 3.01 +/- 1.58). One hundred sixty-eight patients had a positive [13C]urea breath test (mean = 25.43 +/- 16.90). One hundred fifty-five patients were common to both the groups. Statistical analysis did not reveal any relationship between quantitative [13C]urea breath test results or H. pylori IgG values and endoscopic diagnoses.

CONCLUSION

The magnitude of [13C]urea breath test or H. pylori IgG serology cannot be used to predict the presence or absence of gastroduodenal ulcer disease.

Prospective evaluation of a new urea-membrane test for the detection of Helicobacter pylori in gastric antral tissue

AIM

To determine the sensitivity, specificity, and positive and negative predictive values of a newly developed urea-membrane test for the detection of Helicobacter pylori in gastric tissue.

METHODS

Patients presenting for upper endoscopy with no recent exposure to H. pylori-altering drugs were enrolled. Antral biopsy specimens were tested by the urea-membrane and urea-gel methods and submitted for histology. Patients underwent [13C]urea breath tests. Presence of H. pylori was established by histology or the combination of a positive [13C]urea breath test and a positive urea-gel test. Absence of H.pylori required both the [13C]urea breath test and the invasive tests to be negative. The urea-membrane test was reported at 1 hour.

RESULTS

Ninety-nine patients (47 men and 52 women) with a mean age of 51.43 +/- 14.9 years participated. Fifty of 99 patients (prevalence, 50.5%) tested positive for H. pylori. The urea-membrane test correctly identified 49 of 50 H. pylori-positive and 46 of 49 H. pylori-negative patients, yielding sensitivity, specificity, and positive and negative predictive values of 98.0%, 93.9%, and 94.2% and 97.9%, respectively, in this population.

CONCLUSIONS

Rapidly available and reliable results from the urea-membrane test can facilitate clinical decision prior to patient discharge from the endoscopy suite.

Testing for Helicobacter pylori in clinical practice

It is now accepted that cure of Helicobacter pylori infection will result in healing of chronic active gastritis and will change the natural history of gastroduodenal ulcer disease. A variety of highly sensitive and specific diagnostic methods have been developed over the past few years to establish whether a patient is infected with this organism. The two major categories of diagnostic tests for H. pylori are invasive methods, which require endoscopy, and noninvasive tests in which endoscopy is not necessary. Invasive tests include rapid urease tests, histology, and culture. Noninvasive tests include various methods of antibody detection and carbon-labeled urea breath tests. This review describes the characteristics, appropriate uses, and comparative accuracy of the available diagnostic tests for detection of H. pylori. It offers suggestions on the test of choice to establish a patient's H. pylori infection status in different clinical settings.

Long-term follow-up of Helicobacter pylori serology after successful eradication

OBJECTIVE

To determine the Helicobacter pylori IgG serology pattern 12-21 months after successful organism eradication and to assess the usefulness of IgG serology in the long-term follow-up of patients.

METHODS

We recruited patients from our 1990-91 study on IgG serology after H. pylori treatment. Forty-three of 45 patients (93%) agreed to participate. They had all been cured of H. pylori infection after triple antibiotic therapy and remained H. pylori negative at 1 yr posttreatment. H. pylori IgG antibody concentrations were measured in serum samples taken at 3-month intervals between 12 and 21 months posttreatment. [13C]-urea breath test was done at each blood draw to ensure continued eradication. Serology was determined by ELISA (Pylori Stat, BioWhittaker, Inc) and expressed as absorbance.

RESULTS

All 43 patients (100%) continued to be free of H. pylori and demonstrated a decline in their H. pylori IgG concentration compared with baseline. The overall decline in serology among all 43 patients was approximately 50%. Forty of 43 patients (93%) had a decline of more than 20% in H. pylori IgG concentration compared with baseline. However, 28 of 43 patients (65%) remained seropositive for more than 1 yr after successful H. pylori eradication.

CONCLUSION

We conclude that a 20% decline in IgG concentration has an overall sensitivity of 93% for determining H. pylori eradication 12-21 months after H. pylori treatment. Serology is an attractive alternative to endoscopy or urea breath tests in monitoring patients after H. pylori treatment, but serum IgG levels should not be expected to reach seronegative range after successful H. pylori eradication.

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.

[13C]urea breath test to confirm eradication of Helicobacter pylori

OBJECTIVE

To determine the utility of the [13C]urea breath test in confirming the eradication of Helicobacter pylori.

METHODS

We reviewed our H. pylori database for patients who underwent [13C]urea breath test at baseline and 6 wk after triple therapy with tetracycline, metronidazole, and bismuth subsalicylate. Baseline infection was defined by the identification of the organism on antral biopsies or a reactive CLO test. Eradication was defined as a negative Warthin-Starry stain and a non-reactive CLO test at 24 h. All patients had a positive baseline [13C]urea breath test defined as [13C] enrichment > 6% at 60 min.

RESULTS

One hundred eighteen H. pylori-infected patients (mean age 58.3 +/- 13.9 yr) met the review criteria (61 duodenal ulcers, 24 gastric ulcers, 33 non-ulcer dyspepsia). In 101/118 patients (86%), H. pylori was successfully eradicated (mean baseline breath test value 25.8 +/- 1.6). Of 101 patients, 95 had a negative 6-wk follow-up breath test (mean 2.2 +/- 0.2, p < 0.001). Of the 6/101 patients in whom treatment was successful, and who remained breath test positive at 6 wk, 4/6 were breath test negative when retested at 3 months. The remaining two patients were lost to follow-up. In 17/118 (14%) patients, H. pylori failed to be eradicated (mean baseline breath test 22.4 +/- 3.6). Fifteen of 17 patients had a positive breath test at 6 wk (mean 19.9 +/- 3.7). Two of 17 with a negative breath test at 6 wk tested positive when the breath test was repeated at 3 months. The sensitivity and specificity of [13C]urea breath test at 6 wk posttreatment are 97% and 71%, respectively. The positive and negative predictive values are 94% and 88%, respectively.

CONCLUSIONS

[13C]urea breath test is a sensitive indicator of H. pylori eradication 6 wk after treatment. Antral biopsies are unnecessary to confirm eradication of H. pylori after completion of treatment.

Long-term Helicobacter pylori recurrence after successful eradication with triple therapy

To establish the rate of Helicobacter pylori recurrence after a standard triple-therapy regimen (bismuth subsalicylate, tetracycline, metronidazole) and determine which clinical factors affect reinfection, we prospectively followed 118 patients after successful H. pylori eradication. Elimination of H. pylori was confirmed by repeat endoscopy and urea breath test 4 wk after completion of therapy. Serial [13C]urea breath tests were performed at 3-month intervals; antral biopsies were used to verify reinfection. Recurrence of H. pylori infection occurred in 4/118 (3.4%) patients. Three of the four relapses occurred in the 1st yr after treatment. Gender, age, ethnic group, alcohol consumption, cigarette use, and gastrointestinal diagnosis do not predict H. pylori recurrence. We conclude that the rate of recurrence after successful H. pylori eradication is low, and that when reinfection takes place, it occurs most commonly within the 1st yr after treatment.

Patient factors affecting Helicobacter pylori eradication with triple therapy

Duodenal ulcer recurrence and gastritis are reduced with successful Helicobacter pylori treatment. To identify the patient factor influencing H. pylori eradication, we prospectively evaluated 96 consecutive patients undergoing a single 2-wk course of bismuth, tetracycline, and metronidazole therapy. At the time of initial esophagogastroduodenoscopy with biopsies, each patient had a profile obtained which included demographic information, gastrointestinal pathology, and H. pylori status of the spouse. Elimination of H. pylori was confirmed by repeat esophagogastroduodenoscopy with biopsies 4 wk after the completion of therapy and serial urea breath tests. Eradication at 4 wk was successful in 80 of 96 (83%) patients. On multivariate analysis, H. pylori elimination was associated with advanced age (p = 0.002) and a greater amount of chronic inflammation on baseline antral biopsy (p = 0.024). Eradication was inversely associated with the presence of a gastric ulcer (p = 0.008) and lack of medication compliance (p = 0.030). Successful eradication reduced the severity of both acute and chronic antral mucosal inflammation. Household income, gender, ethnic group, smoking, alcohol intake, and H. pylori status of the spouse did not differ between the eradicated and noneradicated groups. We conclude that it will be important to control for influential patient factors in future studies of H. pylori treatment regimens.

Hereditary angioedema associated with pancreatitis

A 44-year-old woman with C1q esterase inhibitor deficiency was seen in consultation for recurrent right upper quadrant abdominal discomfort, nausea, and vomiting. Each of these episodes was accompanied by concomitant peripheral edema. Initial diagnostic efforts were fruitless. In time, intermittent elevations in amylase and lipase developed, and a diagnosis of relapsing pancreatitis was made. We contend that the patient's recurrent acute pancreatitis is associated with her hereditary angioedema. Possible pathogenesis could involve intermittent intrapancreatic edema with partial ductal obstruction or loss of inhibition on the kallikrein-kinin system.

Physician performance and patient perceptions during the rectal examination

OBJECTIVE

To describe internal medicine residents' training and performance as well as patients' attitudes and knowledge regarding the rectal examination.

DESIGN

Descriptive survey of university-trained internal medicine residents and general medicine clinic patients.

SETTING

General internal medicine residents' longitudinal clinic at a university-affiliated Veterans Affairs Medical Center.

PATIENTS/PARTICIPANTS

Ambulatory male veterans attending their general internal medicine clinic, all of whom were over the age of 40 years and had previously had a rectal examination (n = 100), as well as all second- and third-year University of Minnesota internal medicine residents (n = 78) were surveyed using a self-administered questionnaire.

MEASUREMENTS AND MAIN RESULTS

Residents differed in their training in, practice of, and understanding of indications for the rectal examination. Little formal instruction regarding patient comfort had been provided to residents, and many residents had never received supervised instruction in the rectal examination. Patients frequently were uncertain about why the examination had been performed, lacked understanding of the results of the examination, and often had preferences for examination comfort measures that differed from those utilized by their physicians.

CONCLUSIONS

Increased supervised instruction in the rectal examination in medical training programs is recommended. This should emphasize not only appropriate indications for this procedure but also attention to patient communication and comfort.