The CLO test in the UK: inappropriate reading and missed results

A time-saving-modified Giemsa stain is a better diagnostic method of Helicobacter pylori infection compared with the rapid urease test

Background

Despite having chronic gastritis, most people infected by Helicobacter pylori (H. pylori) are asymptomatic and have no specific clinical signs and symptoms. H. pylori infection can be diagnosed by several detection methods. Giemsa stain and rapid urease test (CLO test) are the most performed tests of H. pylori infection at first‐line clinical examination because of their simplicity and reliability. However, the sensitivity of CLO test is significantly reduced in patients with atrophic gastritis and intestinal metaplasia, and the weaknesses of Giemsa stain are higher cost and time‐consuming.

Methods

The Giemsa stain was modified in several staining solutions and procedures based on the simplified Giemsa technique described by Gray, Wyatt, & Rathbone (1986). The modified Giemsa stain is examined its efficacy and compared with the CLO test using 233 H. pylori‐infected patients with gastric disease.

Results

The modified Giemsa stain is comparable to the traditional one. Statistical analysis indicated that the modified Giemsa stain obtains greater accuracy in H. pylori‐infected patients with gastritis and ulcer than the CLO test (48.1% vs. 43.7%). Moreover, considering the prognosis of different symptoms of gastric diseases, the modified Giemsa stain has a more accurate prognosis than combination symptoms (P = 1.8E‐05 vs. P = 5.49E‐05). The modified Giemsa stain is confirmed to be better than CLO test using 233 H. pylori‐infected patients with gastric disease.

Conclusions

The modified Giemsa stain is more simplified and time‐saving than traditional Giemsa stain, which is comparable to the traditional one and is confirmed to be better than CLO test using 233 H. pylori‐infected patients with gastric disease. In clinical examination, this modified Giemsa stain can be applied to routine examination and provides quick and accurate diagnosis and prognosis to H. pylori‐infected patients with gastric diseases.

New monoclonal antibody-based test for Helicobacter pylori urease in gastric tissue

BACKGROUND/AIMS

To evaluate a new monoclonal antibody for Helicobacter pylori urease in gastric tissue.

METHODS

A total of 107 volunteers were enrolled. All subjects underwent a (13)C-urea breath test and esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia. Six biopsy specimens in the gastric antrum and body were obtained for a rapid urease test and histology. The new monoclonal antibody-based H. pylori urease test (HPU) was performed to rapidly and qualitatively detect urease in two biopsy specimens.

RESULTS

H. pylori infection was diagnosed in 73 subjects. The sensitivity and specificity of the HPU was 89% and 74%, respectively. The subjects were divided into two groups: one with true-positive and true-negative HPU results (n = 90) and the other with false-positive and false-negative HPU results (n = 17). Across all subjects, ammonia levels were 900.5 ± 646.7 and 604.3 ± 594.3 μmol/L (p > 0.05), and pH was 3.37 ± 1.64 and 2.82 ± 1.51 (p > 0.05). Sensitivity was higher in the presence of atrophic gastritis or intestinal metaplasia.

CONCLUSIONS

HPU detected H. pylori in approximately 10 min. Gastric aspirate ammonia and pH levels did not affect the test results. Sensitivity was good in the presence of atrophic gastritis or intestinal metaplasia.

Detection of Helicobacter pylori in Gastric Aspirates Using a Monoclonal Antibody-Based Test

Background/Aims

The objective of this study was to evaluate a monoclonal antibody-based test to detect Helicobacter pylori-specific antigen in gastric aspirates from humans.

Methods

Sixty-one volunteers were enrolled in the study. All of the subjects underwent a ¹³C-urea breath test (UBT) before esophagogastroduodenoscopy. Gastric aspirates were analyzed for pH and ammonia and used for polymerase chain reaction (PCR), culture, and monoclonal antibody-based detection of H. pylori. Multiple biopsies of the gastric antrum and body were obtained for a rapid urease test (RUT) and histological evaluation.

Results

Thirty-six subjects were H. pylori-positive and 25 were H. pylori-negative according to the UBT results. Compared with the H. pylori-negative subjects, H. pylori-positive subjects had a higher pH (4.77±1.77 vs 3.49±1.30, p<0.05) and ammonia level (1,130.9±767.4 vs 184.2±126.3, p<0.0001). The sensitivities and specificities of the PCR test, RUT, culture test, and monoclonal antibody-based test were 100% and 72%, 89% and 100%, 47% and 100%, and 78% and 100%, respectively.

Conclusions

The monoclonal antibody-based test for diagnosing H. pylori infection in gastric aspirates has increased sensitivity compared with the culture test and specificity as high as that of the RUT. The test may be useful as an additive test for examining gastric aspirates.

Detection of Helicobacter pylori: A faster urease test can save resources

AIM: To investigate whether differences in the rapidity of a positive result for Helicobacter pylori can save resources, by comparing two commercially available urease kits.

METHODS: One hundred and eighty-five adults (130 outpatients, 55 inpatients) undergoing gastroscopy were entered prospectively. Patients were divided into two groups: Group 1 (if they were not on PPIs, antibiotics, H₂A, bismuth or sucralfate for up to 14 d prior to the endoscopy) and Group 2 (if they were on, or had been on, any of the above medication in the previous 14 d). At endoscopy two sets of biopsies, taken in random order, were placed in the wells of the Campylobacter-like organism (CLO) test (Kimberly-Clark, Utah, USA) and the Quick test (Biohit Plc, Helsinki, Finland). Five additional gastric biopsies were taken for histology/Giemsa and immunohistochemical study. The two urease test slides were read at 2 min, 30 min, 2 h and 24 h. Sensitivity and specificity at 24 h were determined.

RESULTS: At 24 h, for all patients, there was no difference in sensitivity (100% vs 97.5%), specificity (99.3%), positive (97.5%) and negative predictive values (100% vs 99.3%) between the CLO and Quick tests, respectively. There was a positive result at 30 min in 17/41 (41.5%) CLO tests, and in 28/40 (70%) Quick tests, P = 0.05. Quick test enabled the prescription of eradication therapy before discharge in all 28/40 patients. Only 12 (30%) follow-up appointments were needed. If the CLO test had been used alone, only 17 (41.5%) prescriptions would have been possible prior to discharge and 24 (58%) follow-up appointments would be needed (P = 0.001). Of 2000 gastroscopies performed annually at our unit, a saving of 123 follow-up appointments (total: 8856 Euros or 11 808 USD) would be achieved if we switched to the Quick test.

CONCLUSION: Direct comparison of locally available urease test kits is worthwhile, since the appropriate choice results in a significant saving of resources. Local costs and follow-up protocols will determine the magnitude of these savings.

Endoscopic diagnoses and CLO test results in 9239 cases, prevalence of Helicobacter pylori in Istanbul, Turkey

BACKGROUND

Helicobacter pylori is implicated in the etiology of gastric and duodenal ulcer, non-ulcer dispepsia, atrophic gastritis, gastric adenocarcinoma and lymphoma.

METHODS

Between November 1995 and December 2004, the presence of H. pylori was investigated using the CLO test in 9239 patients who underwent upper gastrointestinal endoscopy at a single institution in Istanbul, Turkey. The results were evaluated as early-late positive, and negative.

RESULTS

There were 4667 women (50.51%) with a mean age of 44.5 years (range, 13-90 years), and 4572 men (49.49%) with a mean age of 45.7 years (range, 11-85 years). The CLO test was positive in 41.44% of cases. The most frequent symptoms on admission were epigastric pain (46.2%) and burning (19.6%). The most frequent endoscopic diagnosis was pangastritis (64%) and non-erosive duodenitis (30.5%). The H. pylori positivity was 61.53% during the first 5-year period and 38.47% during the second 5-year period. The H. pylori positivity was significant in patients using non-steroidal anti-inflamatory drugs and tobacco (P < 0.001).

DISCUSSION AND CONCLUSION

Helicbacter pylori prevelance remains an important health problem for Turkey although it has diminished in parallel to the national development during the last years. Helicbacter pylori, as a first-degree carcinogen, should be investigated and eradicated particularly in high-risk patients.

Helicobacter pylori detection and antimicrobial susceptibility testing

The discovery of Helicobacter pylori in 1982 was the starting point of a revolution concerning the concepts and management of gastroduodenal diseases. It is now well accepted that the most common stomach disease, peptic ulcer disease, is an infectious disease, and all consensus conferences agree that the causative agent, H. pylori, must be treated with antibiotics. Furthermore, the concept emerged that this bacterium could be the trigger of various malignant diseases of the stomach, and it is now a model for chronic bacterial infections causing cancer. Most of the many different techniques involved in diagnosis of H. pylori infection are performed in clinical microbiology laboratories. The aim of this article is to review the current status of these methods and their application, highlighting the important progress which has been made in the past decade. Both invasive and noninvasive techniques will be reviewed.

Helicobacter pylori and antimicrobial resistance: molecular mechanisms and clinical implications

Helicobacter pylori is an important human pathogen that colonises the stomach of about half of the world's population. The bacterium has now been accepted as the causative agent of several gastroduodenal disorders, ranging from chronic active gastritis and peptic ulcer disease to gastric cancer. The recognition of H pylori as a gastric pathogen has had a substantial effect on gastroenterological practice, since many untreatable gastroduodenal disorders with uncertain cause became curable infectious diseases. Treatment of H pylori infection results in ulcer healing and can reduce the risk of gastric cancer development. Although H pylori is susceptible to many antibiotics in vitro, only a few antibiotics can be used in vivo to cure the infection. The frequent indication for anti-H pylori therapy, together with the limited choice of antibiotics, has resulted in the development of antibiotic resistance in H pylori, which substantially impairs the treatment of H pylori-associated disorders. Antimicrobial resistance in H pylori is widespread, and although the prevalence of antimicrobial resistance shows regional variation per antibiotic, it can be as high as 95%. We focus on the treatment of H pylori infection and on the clinical relevance, mechanisms, and diagnosis of antimicrobial resistance.

HELICOBACTER PYLORI INFECTION AND TREATMENT OUTCOME IN AN URBAN AUSTRALIAN POPULATION

BACKGROUND

To examine the rate of Helicobacter pylori infection in a group of symptomatic patients using rapid urease test and antral histology and report on their treatment outcomes.

METHODS

From a single-surgeon series in a tertiary teaching hospital, 200 consecutive symptomatic patients undergoing their first diagnostic upper gastrointestinal endoscopy during 2003-2004 were included in this retrospective audit. Campylobacter-like organism (CLO) test results were compared with the results of conventional histological examination plus Giemsa staining. Eradication rates and demographic data were collected.

RESULTS

One hundred and seventy-nine of 200 (89.5%) patients had antral biopsies for histology and for CLOtest. The CLOtest was positive in 31% (56/179) of patients. Thirty-two of 56 (57%) patients had an early-positive CLOtest (<24 h). The remaining 43% (24/56) of patients had a late-positive CLOtest (>24 h). Histological examination of the antral biopsy showed evidence of H. pylori in 28/56 (50%) patients with a positive CLOtest. H. pylori eradication therapy was prescribed in 51/56 (91%) patients with a positive CLOtest. Forty-five of 51 (88%) of these patients had a subsequent urea breath test. Urea breath test was positive in 17/45 (29%) patients after H. pylori eradication therapy was prescribed.

CONCLUSION

Rate of H. pylori in this series of symptomatic patients was 31%. As nearly half of the CLOtests became positive after 24 h, we suggest that the CLOtest should be re-examined 24 h after gastroscopy. Standard antral histology and CLOtest were in agreement in only 50% of cases, suggesting that the CLOtest is a more sensitive test. The failure rate of 29% for initial H. pylori eradication therapy reinforces the need for follow up after treatment.

Peptic ulcer disease today

Over the past few decades, since the introduction of histamine H(2)-receptor antagonists, proton-pump inhibitors, cyclo-oxygenase-2-selective anti-inflammatory drugs (coxibs), and eradication of Helicobacter pylori infection, the incidence of peptic ulcer disease and ulcer complications has decreased. There has, however, been an increase in ulcer bleeding, especially in elderly patients. At present, there are several management issues that need to be solved: how to manage H. pylori infection when eradication failure rates are high; how best to prevent ulcers developing and recurring in nonsteroidal anti-inflammatory drug (NSAID) and aspirin users; and how to treat non-NSAID, non-H. pylori-associated peptic ulcers. Looking for H. pylori infection, the overt or surreptitious use of NSAIDs and/or aspirin, and the possibility of an acid hypersecretory state are important diagnostic considerations that determine the therapeutic approach. Combined treatment with antisecretory therapy and antibiotics for 1-2 weeks is the first-line choice for H. pylori eradication therapy. For patients at risk of developing an ulcer or ulcer complications, it is important to choose carefully which anti-inflammatory drugs, nonselective NSAIDs or coxibs to use, based on a risk assessment of the patient, especially if the high-risk patient also requires aspirin. Testing for and eradicating H. pylori infection in patients is recommended before starting NSAID therapy, and for those currently taking NSAIDs, when there is a history of ulcers or ulcer complications. Understanding the pathophysiology and best treatment strategies for non-NSAID, non-H. pylori-associated peptic ulcers presents a challenge.

Recurrence of Helicobacter pylori infection 1 year after successful treatment: prospective cohort study in the Republic of Yemen

OBJECTIVES

To investigate the prevalence of Helicobacter pylori infection in dyspeptic patients in the Republic of Yemen and the recurrence rate 1 year after apparently successful eradication.

METHODS

A total of 275 patients with chronic dyspepsia seen in one clinic were enrolled. Gastric biopsies were obtained at endoscopy and H. pylori infection was diagnosed using the rapid urease test. Patients with H. pylori infection were given either clarithromycin or metronidazole-based triple therapy. Six weeks later H. pylori status was assessed using the C-urea breath test (C-UBT). Those who were negative for H. pylori had a further C-UBT after 1 year to establish the recurrence rate.

RESULTS

The prevalence of H. pylori infection at entry to the study was 82.2% [95% confidence interval (CI) 78-87%]. The overall eradication rate 6 weeks after treatment was 49.1% (95% CI 42.6-55.6%) by intention-to-treat analysis, and 60% (95% CI 53-67%) by per-protocol analysis. Recurrence rate of H. pylori infection at 1 year was 34% (95% CI 14-45%) and the only predictor of recurrence was an excess delta C-UBT value less than 3.5 per million but equal to or greater than 2.5 per million at 6 weeks after treatment (odds ratio 2.28; 95% CI 1.17-4.44; P = 0.028).

CONCLUSION

The prevalence of H. pylori infection in dyspeptic patients in Yemen is very high, the eradication rate with standard triple therapy was unsatisfactory probably because of widespread bacterial resistance due to unrestricted antibiotic use. The recurrence rate of infection at 1 year was high, as a result of recrudescence of incompletely eradicated organisms rather than reinfection.