Rapid diagnosis of Campylobacter pylori by brush cytology

Practical rapid, minimally invasive, reliable nonendoscopic method to obtain Helicobacter pylori for culture

BACKGROUND

Helicobacter pylori culture typically requires endoscopy.

AIM

To develop a minimally invasive rapid and reliable method to obtain H. pylori cultures.

METHODS

An extendable oro-gastric brush, contained within a plastic over-tube, was constructed (Baylor Brush, US Endoscopy). After topical oral anesthesia, the 5-mm diameter brush assembly was swallowed. The brush was extended in the stomach and the mucosa was brushed three or four times. The brush was then retracted into the protective sleeve and withdrawn from the patient. The brush was either cultured directly or placed in cysteine transport medium with 20% glycerol which was then sampled immediately or after freezing at -70 degrees C.

RESULTS

Twenty-five adult H. pylori-infected subjects (13 male, 12 female) were studied. Helicobacter pylori recovery rate was 100% (11 of 11) when cultured immediately or after storage in transport medium at -70 degrees C for 1 or 2 weeks or after storage at 4 degrees C for 24 hours (four of four) or 72 hours (four of four) before being cultured. Freezing on dry ice and air shipment did not reduce recovery.

CONCLUSION

Rapid, reliable, nonendoscopic culture of gastric mucus is a practical method to obtain culture of H. pylori for clinical or research purposes. The method is amenable to being performed in a doctor's office or in the field.

Usefulness of Leifson staining method in diagnosis of Helicobacter pylori infection

The Leifson staining method was used to diagnose Helicobacter pylori infection and was compared to histology, culture, and the rapid urease test (RUT). Histology gave the best sensitivity (98%), compared to Leifson staining (97%), culture (92%), and RUT (85%) (P < 0.005). Leifson staining is a sensitive, rapid, economical method for diagnosis of H. pylori infection in dyspeptic patients.

Diagnosing Helicobacter pylori by imprint cytology: can the same biopsy specimen be used for histology?

Imprint cytology of the gastric mucosa has been found to be very simple, inexpensive, and rapid for diagnosing Helicobacter pylori infection. However, there is a fear that preparing imprint smears may damage the biopsy specimen for subsequent histologic examination. This study was planned to investigate whether this damage happens. Four antral biopsy specimens were obtained from each of the 100 patients undergoing upper gastrointestinal endoscopy. Imprint smears were made from two biopsy specimens, which were then fixed in 10% formal saline and sent for histologic study. The third and fourth biopsy specimens were directed fixed in 10% formal saline for histologic examination. Two pathologists examined the imprint smears. Agreement between the two observers was observed in 97% of cases. Beyond-chance agreement was good with a kappa index of 0.90. H. pylori organisms were seen in 82% of biopsy specimens from which imprint smears were prepared and in the same percentage of biopsy specimens that were processed directly. The pathologists could not identify the histologic sections form which imprints were made. It is concluded that imprint cytology is an excellent method of diagnosing H. pylori infection and that preparing imprint smears does not alter the quality of the tissue. The same biopsy specimen can be used for histologic studies.

Frozen-section biopsy in perendoscopic diagnosis of Helicobacter pylori

BACKGROUND

Our goal was to investigate how reliably Helicobacter pylori infection can be diagnosed from gastric biopsy specimens by frozen-section technique.

PATIENTS AND METHODS

The series consisted of 105 consecutive outpatients who underwent diagnostic upper gastrointestinal endoscopy for abdominal complaints at Jorvi Hospital (Espoo, Finland) during the beginning of 1996. Endoscopic biopsies from antrum and corpus were taken for both frozen-section and traditional histology, the latter serving as reference (control) material. In the frozen-section technique, the biopsy specimens were transferred immediately to the pathology laboratory, were prefixed for 30 sec in 10% neutral formalin, were frozen in liquid nitrogen, and were cut into sections with a cryostat. The sections were stained for 10 minutes with 1% toluidine blue. The control biopsy specimens were fixed overnight in 10% neutral formalin and embedded in paraffin, and the sections were stained with the modified Giemsa method.

RESULTS

In the diagnosis of H. pylori infection, both the sensitivity and the specificity of the frozen-section technique were 98% compared to the findings in the reference series. One false-negative result occurred among 41 positive cases, and one case erroneously was classified positive among 64 cases that were negative for H. pylori in the ordinary histology. The frozen-section technique slightly underestimated the degree of colonization of the gastric mucosa by H. pylori, compared to the findings in the reference material. In the diagnosis of gastritis (chronic inflammation of any degree), the sensitivity and specificity of frozen sections were 92% and 95%, respectively. In the frozen-section technique, the report of the pathologist of the presence or absence of H. pylori gastritis in biopsy specimens could be given to the gastroenterologist by telephone in approximately 20 minutes.

CONCLUSIONS

The frozen-section technique is a reliable and rapid method for the diagnosis of H. pylori and provides possibilities for perendoscopic diagnosis of the infection in the hospitals where the frozen-section service is available.

Comparison of diagnostic methods for detecting gastric Helicobacter-like organisms in dogs and cats

Diagnostic methods for detecting gastric Helicobacter-like organisms (GHLOs) in dogs and cats were compared. Samples for brush cytology, the urease test and histological examination were collected post mortem from the fundus, corpus and antrum of 10 dogs (17 sample sites from each animal) and 10 cats (14 sample sites each). Samples of tissue from the fundus or corpus were taken for transmission electron microscopy and culture from three and eight dogs, respectively, and from six cats that gave a positive urease test with samples from these regions. In all dogs and in six of the 10 cats, GHLOs were detected by at least one of three methods (brush cytology, urease test or histological examination) in all regions. By brush cytology, GHLOs were demonstrated in all samples from the dogs and the positive cats. In cats, the urease test (60 min) gave a positive result in every sample site; in dogs it gave a positive result in 100% of the corpus samples, in 95% of the fundus samples and in 62% of the antral samples. Histological examination revealed GHLOs in all samples from the fundus and corpus of the dogs and of the positive cats; and in 74% and 91.7% of the antral samples of the dogs and cats, respectively. GHLOs were seen in all dogs and cats studied by transmission electron microscopy, and culture of gastric tissue was successful in 3/8 dogs and 1/6 cats. In this study, brush cytology was thus the most sensitive method for demonstrating GHLOs.

Brush cytology: a reliable method to detect Helicobacter pylori

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

Effect of specimen collection techniques, transport media, and incubation of cultures on the detection rate of Helicobacter pylori

Culture and histologic examination are considered "gold standard" methods for the detection of Helicobacter pylori, but discrepancies may occur with either method. Failure to detect Helicobacter pylori may be due to sampling error, inappropriate transport or culture media, or insufficient duration of the incubation period. Rates of detection of Helicobacter pylori by culture and histopathologic examination of gastric mucosal biopsy specimens were determined in 102 consecutive dyspeptic patients. In a separate group of 60 patients, rates of detection of Helicobacter pylori by culture of antral brushings and the length of incubation required in selective and nonselective culture media were studied. In the first group of 102 patients, the combination of culture and histologic examination detected 54 Helicobacter pylori-positive patients, whereas the separate techniques each detected 51 Helicobacter pylori-positive patients. In the second group of 60 patients evaluated by culture of antral brushings, the rate of detection of Helicobacter pylori was 25 of 60 and was similar for culture (25/60) and histologic examination (25/60). In the second group the length of incubation required to detect Helicobacter pylori was different for selective and nonselective media. In nonselective media, incubation of up to ten days was required to detect all Helicobacter pylori infections, whereas in selective media seven days was sufficient. Rates of detection of Helicobacter pylori by culture, histopathologic examination and culture from brushings were similar, whereas the combination of culture and histopathologic examination achieved a superior rate of detection. The incubation period required for the detection of Helicobacter pylori by culture was a minimum of seven days and was dependent on the culture medium used.

Helicobacter pylori in gastroduodenal diseases: rapid identification by endoscopic brush cytology

Previous reports showed Helicobacter pylori (H. pylori) in type B gastritis-affected stomachs. This study was carried out to compare H. pylori staining effectiveness on biopsy to brush cytology. Tissue and brush parallel samples of gastric mucosa with abnormal or normal appearances were examined: 57.6% H. pylori-positive pieces from the antrum and 19.2% from the body were found, versus 65.3% and 25% H. pylori-positive brush smears, respectively. H. pylori resembling organisms were mainly related to chronic and acute antral inflammations and were often associated with higher amounts of round-shaped cocco-bacteria. In addition, H. pylori direct stain on brushing is proposed as the most rapid and reliable method for the routine diagnosis of Helicobacter pylori infection, in both ulcer or nonulcer gastritis.

Imprint cytology--a cheap, rapid and effective method for diagnosing Helicobacter pylori

To compare the efficacy of imprint cytology, histology and CLO-test (for biopsy urease) in detecting Helicobacter pylori infection, antral biopsies were taken from 239 patients undergoing upper gastrointestinal endoscopy. Both imprint cytology and histology showed the presence of H. pylori in 215 (90%) patients. The sensitivity and specificity of imprint cytology vis-à-vis histology was noted to be 100%. The CLO-test was performed in 165 patients and was positive in 130 (79%) patients. The sensitivity and specificity of the CLO-test were 89% and 95%, respectively. The median time required for the CLO-test to become positive and for imprint was 60 minutes for each. The sensitivity of the CLO-test was reduced further in patients receiving colloidal bismuth subcitrate. Of the 27 patients receiving the drug the sensitivity of the CLO-test was only 9% after 4 weeks of therapy. However, the specificity was 100%. The sensitivity and specificity of imprint cytology were unaffected by the antimicrobial therapy and after 4 weeks of treatment were still 100%. It is concluded that the CLO-test has a lower sensitivity and specificity for diagnosing H. pylori infection compared to imprint cytology, which had a sensitivity and specificity equal to that of histology. Imprint cytology may be prepared as an adjunct to histology in patients in whom antral biopsies are taken as it offers a relatively quick diagnosis of H. pylori infection, is considerably cheaper than the CLO-test and does not require additional biopsy material.

Helicobacter pylori: aggressor or innocent bystander?

Helicobacter pylori seeks gastric mucosa, whether found in the stomach, duodenum, or Barrett's esophagus. Definitive diagnosis can be secured by appropriate stains of mucosal biopsies and culture, but the rapid urease test, breath isotope studies, and serologic testing are also useful. The frequency of colonization increases with advancing age, but infection occurs earlier in underdeveloped countries. Although the reservoir is uncertain, water or food transmission seems likely. There is sufficient evidence to assign an etiologic role to the bacteria in the causation of type B antral gastritis. H. pylori is found in areas of gastric metaplasia within the duodenum and is associated with duodenitis. Although acute infection leads to hypochlorhydria, chronic colonization has little effect on acid secretion. Studies have thus far failed to establish a convincing relationship between H. pylori and nonulcer dyspepsia, although the bacteria may play a role in selected patients. H. pylori is found in association with most idiopathic gastric and duodenal ulcers, but it is unclear as to whether the bacteria plays a causative or permissive role. The organism has a predilection for intercellular spaces and the mucous layer, thus affording relative isolation from luminally active antibiotics. Monotherapy with bismuth preparations transiently eliminates the bacteria, but recolonization is rapid, probably due to regrowth of sequestered organisms. A combination of metronidazole, bismuth, and tetracycline (or amoxicillin) affords the best eradication rate, but the potential side effects of this program should be considered. The present therapy of duodenal ulcer disease is effective and without significant risk. Treatment of H. pylori should be reserved for those patients who relapse on adequate maintenance therapy. If a safe and effective antibiotic becomes available, more frequent testing and earlier treatment intervention may become more attractive. H. pylori is probably an "innocent bystander" for most patients, but the bacteria may sufficiently impair the defenses of the antral and duodenal mucosa to facilitate the development and relapse of ulcer disease in subsets of patients.