Pylori In Gastric Biopsy Specimens Research Articles

Prevalence of Helicobacter felis and Helicobacter heilmannii and Co-infection With Helicobacter pylori in Gastric Biopsy Specimens in Endoscopy Ward of Shahid Beheshti Hospital, Hamadan City, Iran

Background: Helicobacter pylori (H. pylori) has various strains associated with human infections. H. pylori, H. heilmannii, and H. felis are the most common strains in humans. H. pylori is associated with several human diseases such as chronic gastritis, peptic ulcer, mucous membrane lymphoma, and gastric adenocarcinoma. This study aimed to determine the prevalence rates of H. felis and H. heilmannii and the effect of co-infection with H. pylori in gastric biopsy specimens of patients. Methods: Totally, 80 gastric biopsy specimens were taken by a physician from the patients referred to Shahid Beheshti Hospital, Hamadan City, Iran. PCR test was used to confirm the presence of H. pylori in samples that had positive rapid urease tests. Moreover, the ureB gene and ureA and ureB genes were used for H. heilmannii and H. felis, respectively. Results: Of the study patients, 61.5% were females, and 38.5% were males with a mean age of 37.8 years. Of 80 biopsies, 50% were H. pylori-positive, 53.8% were H. heilmannii-positive, but no H. felis was identified in any sample. Results indicate that smoking, having a history of gastrointestinal diseases, and taking certain medications can be risk factors for H. pylori. Conclusion: Any agent contributing to gastric mucosal damage can enhance the susceptibility to bacterial contamination. Overall, the results indicate a low probability of interactions between H. pylori, H. heilmannii, and H. felis.

Prevalence of Helicobacter felis and Helicobacter heilmannii and Co-infection With Helicobacter pylori in Gastric Biopsy Specimens in Endoscopy Ward of Shahid Beheshti Hospital, Hamadan City, Iran

Background: Helicobacter pylori (H. pylori) has various strains associated with human infections. H. pylori, H. heilmannii, and H. felis are the most common strains in humans. H. pylori is associated with several human diseases such as chronic gastritis, peptic ulcer, mucous membrane lymphoma, and gastric adenocarcinoma. This study aimed to determine the prevalence rates of H. felis and H. heilmannii and the effect of co-infection with H. pylori in gastric biopsy specimens of patients. Methods: Totally, 80 gastric biopsy specimens were taken by a physician from the patients referred to Shahid Beheshti Hospital, Hamadan City, Iran. PCR test was used to confirm the presence of H. pylori in samples that had positive rapid urease tests. Moreover, the ureB gene and ureA and ureB genes were used for H. heilmannii and H. felis, respectively. Results: Of the study patients, 61.5% were females, and 38.5% were males with a mean age of 37.8 years. Of 80 biopsies, 50% were H. pylori-positive, 53.8% were H. heilmannii-positive, but no H. felis was identified in any sample. Results indicate that smoking, having a history of gastrointestinal diseases, and taking certain medications can be risk factors for H. pylori. Conclusion: Any agent contributing to gastric mucosal damage can enhance the susceptibility to bacterial contamination. Overall, the results indicate a low probability of interactions between H. pylori, H. heilmannii, and H. felis.

Simultaneous identification and detection of clarithromycin and fluoroquinolone resistance in Helicobacter pylori in gastric biopsy specimens using allele-specific multiplex PCR

Simultaneous identification and detection of clarithromycin and fluoroquinolone resistance in Helicobacter pylori in gastric biopsy specimens using allele-specific multiplex PCR

Upfront special staining for Helicobacter pylori in gastric biopsy specimens is not indicated.

The practice of routine upfront use of special stains in biopsy specimens with minimal or no inflammation has not been evaluated. This study was conducted to determine the value of special stains for Helicobacter pylori in gastric biopsy specimens showing variable degrees of inflammation and to evaluate the practice of upfront ancillary staining of all mucosal biopsy specimens. Immunohistochemical or Diff-Quik stains were done on sections of 570 gastric biopsy specimens. The rates of positivity for H pylori were calculated in each category based on the degree of inflammation and classified as normal, minimal, mild, moderate, or severe. H pylori was not detected in 386 (67.7%) biopsy specimens that were classified as normal (6.0%) or with minimal inflammation (28.2%) or mild inactive gastritis (33.5%). The organism was identified by Diff-Quik or immunohistochemical stain in 76 (89.4%) of 85 with moderate active gastritis and 30 (93.8%) of 32 biopsy specimens showing severe active gastritis. Upfront staining of gastric biopsy specimens is not cost-effective since a significant proportion of the gastric biopsy specimens were normal or showed minimal inflammation; in none of these biopsy specimens was the organism found. Special stains should be performed only in selected biopsy specimens that reveal any degree of chronic active gastritis or moderate inactive gastritis.

Bronchoalveolar pH and inflammatory biomarkers in newly diagnosed IPF and GERD patients: A case-control study

BackgroundSeveral studies have suggested that idiopathic pulmonary fibrosis (IPF) may be related to repeated aspiration of gastric contents over long periods of time. We aimed to investigate differences between pH measured directly in the lung, and biomarkers of acute inflammation in patients with newly diagnosed IPF and in patients with newly diagnosed GERD.Material/MethodsAll subjects (N=61) underwent collection of medical history, physical examination, pulmonary function testing, bronchoscopy, endoscopy, arterial blood gas analyses, and biochemical testing.ResultsPreviously diagnosed GERD was found in 56.7%, typical symptoms of reflux in 80%, and Helicobacter pylori in gastric biopsy specimens in 76.6% of the cases. pH in peripheral branches of bronchi in the cases was 5.32±0.44 and was 6.27±0.31 (p<0.001) in the control group. The average values of LDH, ALP, and CRP in bronchoalveolar aspirate and in serum, as well as TNF-α in bronchoalveolar aspirate, were significantly higher in IPF patients.ConclusionsThe more acidic environment in the bronchoalveolar aspirate of the IPF subjects could contribute to the development or progression of IPF, possibly via changes in local metabolism or by damaging local cells and tissue. However, further studies with larger numbers of patients are required to clarify the role of gastric fluid aspiration in IPF pathogenesis. Our preliminary work has identified inflammatory biomarkers LDH, ALP, and TNF-α as potentially important in the pathologic processes in IPF. Further research is needed to determine their importance in clinical intervention and patient care.

A new biphasic test for the detection of Helicobacter pylori in gastric biopsies

The objective of this study was to create a biphasic cultural method for the detection of Helicobacter pylori in gastric biopsy specimens. The biphasic systems were made by using a urea agar slant with overlaying broth in a single vessel. Initially, three different liquid media including brain–heart infusion broth, Brucella broth, and Bolton broth were tested for their ability to support the growth of H. pylori. Bolton broth with 10% defibrinated horse blood demonstrated a significant increase in the numbers of H. pylori (p<0.05). The result showed that positive urease was used to concentrate viable H. pylori cells where the numbers of bacteria were 105cfu. In addition, the reliable incubation time was at least 36h. In total, 55 biopsies were comparatively studied using commercial rapid urease test and PCR. Seven samples (12.72%) were positive with H. pylori by the biphasic test. With the CLOtest, 6 (10.91%) samples were positive. In conclusion, the Hp biphasic test achieved more positive samples than did the commercial rapid urease test.

PTH-138 Assessing the Positive Predictive Value of Peptic Ulceration on Endoscopy for the Diagnosis of Helicobacter in a General Population

IntroductionHelicobacter Pylori (H. Pylori) is a gramme negative bacillus. It is strongly associated with peptic ulcer disease and gastric cancer. 50% of the population aged over 50 may be infected...

To Stain or Not to Stain...That Remains the Question

Helicobacter pylori causes chronic gastritis and is associated with an increased risk for the development of gastroduodenal ulcers, gastric cancer, and lymphoma.1 The diagnosis of active H pylori infection may be established with high confidence by using stool antigen assays, urease breath tests, and the Campylobacter -like organism (CLO) tests when used in previously untreated patients.2–9 Unfortunately, these methods do not permit mucosal assessment for inflammation-induced injury (or for the presence of other conditions) and are not sufficiently reliable when monitoring patients who receive eradication therapy or proton pump inhibitors.5,6,10–14 Thus, pathologic evaluation of mucosal biopsy specimens is widely used to document H pylori infection.15,16 Organisms are usually detectable in H&E-stained sections, but histochemical (eg, Giemsa, thiazine [modified Giemsa stain], alcian yellow, Genta, and Warthin-Starry) and immunohistochemical stains are widely used to enhance detection. Most authors have found ancillary stains to show comparably high sensitivities (>90%) for H pylori detection, so pathologists generally choose one or more of them based on personal preference.17–19 Rarely, if ever, do pathologists detect H pylori in “normal” uninflamed gastric tissue, and the added value of ancillary tests over H&E stains when histologic findings do not suggest infection has never been convincingly demonstrated. Therefore, the question of whether ancillary stains should be routinely used regardless of the histologic appearance of a gastric biopsy specimen on H&E remains a subject of considerable debate. Data-driven guidelines regarding the use of ancillary stains to detect H pylori in gastric biopsy specimens are not established. Pathologists have historically used their own discretion when ordering histochemical and/or immunohistochemical stains; however, many groups increasingly perform such studies on all gastric biopsy specimens (up-front) or on an established subset of cases, such as those accompanied …

Evaluation of diagnostic methods for the detection of Helicobacter pylori in gastric biopsy specimens of dyspeptic patients

Helicobacter pylori infects nearly 50% of the world’s population. This microorganism is accepted as the most important agent of gastritis and as a risk factor for peptic ulcer disease and gastric adenocarcinoma. Currently many diagnostic methods exist for detecting H. pylori, however they all have limitations, thus it is recommend a combination of at least two methods. The aim of this study was to evaluate diagnostic methods, such as in-house urease test, culture and Polymerase Chain Reaction (PCR), for the detection of the H. pylori in gastric biopsy specimens of 144 dyspeptic patients, using as gold standard the association between histology and rapid urease test. According to the gold standard used in this study, 48 (33.3%) patients were infected with H. pylori, while 96 (66.7%) were classified as not infected. The in-house urease test and the PCR were the most sensitive methods (100%), followed by culture (85.4%). However, the inhouse urease test and the culture were the most specific (100%), followed by PCR (75%). In conclusion, this study showed that, in comparison with the combination of histology and rapid urease test, the in-house urease test and the PCR presented 100% of sensitivity in the diagnosis of gastric infection by H. pylori, while the in-house urease test and the culture reached 100% of specificity. These finding suggest that the combination of two or more methods may improve the accuracy of the H. pylori detection.

Role of Helicobacter pylori cheA gene in chemotaxis in vitro and colonizationin vivo

Objective To determine the effect of cheA gene of Helicobacter pylori in the bacterial chemotaxis in vitro and colonization in vivo. Methods The entire cheA and cheY genes were amplified and cloned from genomic DNA of H. pylori NCTC11637 strain. Subsequently, the prokaryotic expression systems of cheA and cheY genes were generated and the target recombinant proteins rCheA and rCheY were extracted by Ni-NTA affinity chromatography. Rabbits were immunized with either rCheA or rCheY for obtaining antisera, and rCheA-IgG and rCheY-IgG in the antisera were prepared using ammonium sulfate precipitation plus DEAE-52 column chromatography. A suicide plasmid of cheA gene was constructed and then a cheA gene knock-out mutant ( cheA - ) was generated based on homologous recombinant exchange using the suicide plasmid. The cheA- mutant was identified using PCR and sequencing. The phosphorylation levels of CheA and CheY molecules of cheA - and wild-type strain were determined by using rCheA-IgG and rCheY-IgG anchoring the target proteins and protein phosphorylation detection kit. The differences of chemotaxis in vitro and colonization in vivo between cheA- mutant and wild-type strain were compared using chemotactic model and BALB/c infection model of H. pylori. Results The cheA gene knock-out in genome of cheA- mutant was confirmed by the results of PCR and sequencing. After treated with 0. 001-0. 1 mol/L HCI for 10 min, the phosphorylation levels of CheA and CheY molecules of wild-type strain were rapidly descended from ( 59.6 ±11.5) μmol and (55.5 ± 10.2) μmol to ( 10.8 ± 2.6) and (5. 5 ± 1.2) μmol (P ＜ 0.05 ), while the phosphorylation of CheY molecule of cheA - mutant was no markedly changed with a persistent lower level ( P ＞0.05). The diameters [(10-20) ± (2-3) mm] of chemotactic aggregative rings of cheA- mutant were significantly less than those [(16-24) ± (2-3)mm] of wild-type strain (P ＜0.05). The positive isolation rate (90%) of H. pylori in gastric biopsy specimens of mice that infected with wild-type strain was remarkably higher than that (40%) of mice that infected with cheA- mutant (P ＜0.05). The result of fluorescence quantitative was also showed that the numbers (6.3 × 103 ±2.1 × 103 copies/mg) of H. pylori in gastric biopsy specimens of wild-type strain infected mice were significantly larger than those (8.3 × 101 ±3. 1 × 101 copies/mg) in gastric biopsy specimens ofcheA- mutant infected mice (P＜0.05). Conclusion The cheA gene of H. pylori has an important role in the bacterial chemotaxis in vitro and colonization in vivo. Key words: Helicobacter pylori ; cheA gene ; cheY gene ; Gene knock-out ; Chemotaxis ;

&lt;i&gt;Helicobacer pylori&lt;/i&gt; detection using local (in-house) rapid Urease reagent in Jos, Nigeria.

Background: Since the discovery of Helicobacter pylori (H. pylori) by Robin Warren and Barry Marshall in 1982 and its subsequent association with diseases like antral (type B) gastritis, peptic ulcer disease (PUD), gastric cancer and gastric Mucosal Associated Lymphoid Tissue (MALT) lymphoma, various invasive as well as non-invasive methods of detecting the bacterium have been developed. The choice of a particular method usually depends on availability, cost, reliability and convenience of diagnostic facility. Non-availability and high cost of commercially prepared rapid urease test kits have led to the development of locally prepared reagents to serve same purpose. This study compared a locally prepared (“in-house”) rapid urease test solution with standard culture in detecting the presence of H. pylori in gastric biopsies to determine the validity of the former. Materials and Methods: This was a prospective cross sectional study carried out over a 6 months period (April-September 2001) to determine the validity of a locality prepared rapid urease reagent in detecting H. pylori infection among dyspeptic patients at the Jos University Teaching Hospital (JUTH), Jos. Two pairs of antral gastric biopsies were obtained from patients at endoscopy and a pair each was used for rapid urease test using a locally prepared urease reagent and cultures on a horse blood agar. The results of the two methods (cultures being the standard) were analyzed using SPSS (version 11.0) statistical programme and tests of validity carried out. Results: A total of 39 patients made up of 24(61.5%) males and 15(38.5%) females in which rapid urease test were done and culture carried out were studied. The ages of the patients studied ranged from 15 to 70years with mean age of 38.4+12.08 years. 34 (87.2%) and 36 (92.3%) of the patients tested positive to H. pylori using the local rapid urease test and culture respectively. Five (1.3%) and 3 (0.8%) of the patients were negative by rapid urease and cultures respectively. The results of the local rapid urease test were then compared with that of culture. A sensitivity and specificity of 91.7% and 66.7% respectively were obtained for the local rapid urease test. The positive and negative predictive values were 94.1% and 40% respectively. Conclusion: With a sensitivity of 91.7%, the locally prepared rapid urease test is comparable to cultures in detecting H. pylori in gastric biopsy specimens. With this finding and with commercially prepared rapid urease kits either not available or expensive, and cultures cumbersome, the use of locally prepared rapid urease test reagents is appropriate, practicable and sustainable in low resource settings like ours. Sahel Medical Journal Vol. 11 (3) 2008: pp. 93-96

Unreliability of Results of PCR Detection of Helicobacter pylori in Clinical or Environmental Samples

The aim of this study was to compare published Helicobacter pylori primer pairs for their ability to reliably detect H. pylori in gastric biopsy specimens and salivary samples. Detection limits of the 26 PCR primer pairs previously described for detection of H. pylori DNA in clinical samples were determined. Sensitivity and specificity were determined using primers with detection limits of <100 CFU/ml using 50 H. pylori-positive and -negative (by concordance by culture and histology) coded gastric biopsy specimens. These results were then confirmed with gastric biopsy specimens and saliva from patients with confirmed H. pylori status. Five of the twenty-six previously reported primer pairs (HP64-f/HP64-r, HP1/HP2, EHC-U/EHC-L, VAG-F/VAG-R, and ICT37/ICT38) had detection limits of <100 CFU/ml in the presence of gastric tissue. None had 100% specificity or sensitivity; all produced false-positive results. The HP64-f/HP64-r for ureA and HP1/HP2 for 16S rRNA individually had sensitivities and specificities of >90% with gastric biopsy specimens. No combinations of primer pairs improved the results. Using these five primer pairs, 54% of the positive saliva samples were determined to be false positive; both the HP64-f/HP64-r and the HP1/HP2 sets produced false positives with saliva. We conclude that clinicians should not rely on results using current PCR primers alone to decide the H. pylori status of an individual patient or as a basis for treatment decisions. The results of studies based on PCR identification of H. pylori in environmental samples should be viewed with caution. Possibly, specific primers sets can be identified based on the presence of multiple putative virulence factor genes.

A Comparative Study Of The Prevalence Of Helicobacter Pylori Between The Inhabitants Of Areas Of Different Barometric Pressure

Background: There are significant geographical and social differences in the prevalence of Helicobacter pylori. Jordan Valley is located at 280-420 meters below, while Irbid city is at 600 meters above sea level. This study is designed to examine the prevalence of Helicobacter pylori infection in the below and above sea level environments. Patients and Methods: A prospective comparative analysis of the prevalence of Helicobacter pylori in gastric biopsy specimens between patients living in Irbid city (group 1) and those living in the Jordan Valley (group 2) was performed. Another group of patients, originally from the Jordan Valley, who are currently residing in Irbid city for at least the last 10 years (group 3) was examined similarly to investigate the possible role of the genetic factor. Results: The 3 groups were comparable in age, gender distribution, and duration of symptoms. The prevalence of Helicobacter pylori infection in group 1 was 82% (143/171). On the other hand, the prevalence of this infection in group 2 was 70% (66/96), which is significantly lower than that of group 1. The prevalence of this infection in group 3 was significantly indifferent from that of patients from Irbid city (80% (32/40)). Conclusions: It is perhaps the environmental factors including the barometric pressure and seasonal temperature rather than the genetic background that is responsible for the difference of Helicobacter pylori infection between patients of the Jordan Valley and those of Irbid city.

Diagnosis of helicobacter pylori infection by polymerase chain reaction: Is it worth it?

The aim of this study was to determine to what degree polymerase chain reaction (PCR) was superior to histology and culture, and whether a noncommercial urease test was of value, in detecting Helicobacter pylori in gastric biopsy specimens. Gastric biopsy specimens from the antrum and corpus of 134 consenting patients were subjected to PCR, targeting the glmM ( ureC) gene, histology, culture, and a rapid urease test. PCR detected H. pylori in the biopsy specimens from 59 patients. All methods showed a high degree of sensitivity and specificity, but histology gave 2 false-negatives, and culture and the urease test gave 1 false-negative compared with PCR. PCR of a glmM gene segment was superior to the other methods for the detection of H. pylori infection and was comparable to histology in terms of cost. Nevertheless, in this study, histology and culture were found to be relatively reliable methods for examining gastric biopsy specimens.

Quantitative detection for low levels of Helicobacter pylori infection in experimentally infected mice by real-time PCR

Accurate diagnosis of Helicobacter pylori infection is important in both clinical practice and clinical research. Molecular methods are highly specific and sensitive, and various PCR-based tests have been developed to detect H. pylori in gastric biopsy specimens. We optimized a sensitive and specific quantitative SYBR Green I real-time PCR assay for detection of H. pylori based on amplification of the fragment of a 26-kDa Helicobacter species-specific antigen gene that allows for detection of 5 bacterial cells per PCR sample. Under the assay conditions, SYBR Green I real-time PCR is highly reproducible with a precise log-linear relation in the range of six orders of magnitude of bacterial DNA concentrations. For accurate comparison of H. pylori infection in different tissue samples, the amount of total host DNA in each sample is normalized by TaqMan real-time PCR of glyceraldehyde 3-phosphate dehydrogenase ( GAPDH) pseudogenes. The developed method was validated in prophilactically immunized and experimentally infected mice and revealed a level of H. pylori gastric colonisation that was below the limit of detection for a rapid urease test. This new method established for a quantitative analysis of H. pylori in the host's stomach may be useful in experimental studies evaluating new anti- H. pylori drugs and vaccines.

The evaluation of diagnostic methods for the detection of Helicobacter pylori in gastric biopsy specimens

PCR is a rapid, sensitive and accurate method for the specific detection of Helicobacter pylori from gastric biopsy specimens. In our study, 104 gastric tissue specimens from symptomatic adult patients were examined by staining, culture, PCR and nested PCR methods for detection of H. pylori. According to our results, positivity was achieved in 24% (25/104) with Giemsa staining, 34% (36/104) with histopathology, 36% (38/104) with PCR and 41% (43/104) with nested PCR respectively, whereas H. pylori was isolated in only 33% (35/104) of the cultures on the biopsy specimens. Both the sensitivity and the positive predictive value of the nested PCR method were 100%, and both the specificity and negative predictive value were 98%. As a conclusion, our results suggest the nested PCR as a highly valuable method in the detection of H. pylori with a reasonably high sensitivity and specificity.

Assessment of Helicobacter pylori vacA and cagA Genotypes and Host Serological Response

Helicobacter pylori strains can be distinguished by genotyping of virulence-associated genes, such as vacA and cagA. Because serological discrimination between strain types would reduce the need for endoscopy, 61 patients carrying H. pylori were studied by vacA and cagA genotyping of H. pylori in gastric biopsy specimens and by detection of specific serum antibodies. Serological responses to H. pylori were determined by Helicoblot (versions 2.0 and 2.1). Antibodies to CagA also were determined by a rapid anti-CagA assay (Pyloriset screen CagA) as well as by two noncommercially developed enzyme immunoassays, each using a recombinant CagA protein. Assessment of performance of the Helicoblot assays indicated substantial interobserver variation, with kappa values between 0.20 and 0.93. There was no relationship between the serological profiles on the Helicoblot and the genotypes from the same patients, except for strong associations between the presence of anti-CagA and the cagA-positive and vacA s1 H. pylori genotypes. Detection of anti-CagA by the five different assays varied considerably, with kappa values ranging from 0.21 to 0.78. Using the cagA genotype as the "gold standard," the sensitivity and specificity of the anti-CagA assays varied from 71.4 to 85.7% and from 54.2 to 100%, respectively. Thus, serological profiles of antibodies to H. pylori are heterogeneous and, with the exception of anti-CagA antibodies, show no relation to the H. pylori vacA and cagA genotypes. Detection of anti-CagA antibodies is strongly dependent on the test used.

A stain for demonstrating Helicobacter pylori in gastric biopsies

Helicobacter pylori continues to be a significant health care problem. It is associated with a variety of stomach disorders such as gastritis, gastric ulcer disease, gastric carcinoma and B-cell gastric lymphoma. One common method diagnosing an infection by this bacterium is microscopic examination of routine processed gastric or duodenal biopsies. With this type of specimen, it is necessary to demonstrate visually the presence of H. pylori using an appropriate staining technique. This paper presents a simple staining technique for demonstrating H. pylori in gastric biopsy specimens using carbol fuchsin staining against a contrasting background of light green.

Reverse transcription-polymerase chain reaction in the diagnosis of Helicobacter pylori infection in Finnish children.

The purpose of this study was to design a simplified polymerase chain reaction (PCR) technique for the detection of Helicobacter pylori and to compare it with conventional diagnostic methods-culture and histology of gastric biopsy specimens. In addition, the capability of this technique to detect H. pylori in the gastric mucosal biopsies of originally H. pylori-negative children with gastritis or recurrent abdominal pain was investigated. Reverse transcriptase polymerase chain reaction (RT-PCR) using polymerase from Thermus thermophilus was applied to detect H. pylori 16S rRNA. Twenty-five children H. pylori-positive by culture and/or histology were used as positive control subjects. Sixteen healthy H. pylori-negative children served as negative control subjects. Biopsy specimens from gastric antrum and corpus from 81 children were examined by RT-PCR. Altogether, 30 had histologic gastritis and 51 had nonspecific abdominal pain only, with no disease in histologic specimens. Histology and culture of H. pylori were negative in both patient groups. Reverse transcription-polymerase chain reaction detected 24 of 25 tissue-positive and 0 of 16 tissue-negative cases, indicating 96% sensitivity and 100% specificity for the test. None of the culturally and histologically H. pylori-negative samples showed H. pylori colonization when analyzed by RT-PCR. RT-PCR using Thermus thermophilus polymerase is a fast and simple means of detecting H. pylori in gastric biopsy specimens. It is at least as specific and sensitive as conventional methods. In pediatric patients it may be necessary to take more than two biopsy specimens to increase sensitivity in cases of local or patchy colonization.

Interobserver variation in the histopathological assessment of Helicobacter pylori gastritis

The histopathologic detection of Helicobacter pylori in gastric biopsy specimens is considered the gold standard for the diagnosis of H pylori infection. However, few studies have addressed the pathologists' reliability to detect the organism and to assess the degree of the related inflammatory changes. The objectives of this study were to determine the degree of agreement among the findings of four gastrointestinal pathologists in the semiquantitative evaluation of H pylori infection and gastritis. Three slides from specified areas of the stomach of 99 patients with and without H pylori infection were stained with the triple stain, coded, and examined independently by four pathologists. For each specimen, a visual analogue scale graded from 0 (absent/normal) to 5 (maximal intensity) was used to score (1) H pylori (2) neutrophils, and (3) atrophy. Data were analyzed using κ-statistics. The κ-coefficient for the detection of H pylori (present vs absent) was ∼ .9 (excellent); for the intensity of infection, it was considerably lower on the 6-point scale (∼.61) and improved slightly on an amalgamated 4-point scale (∼.71). The agreement on presence or absence of neutrophils was excellent ( κ = .8) in antral biopsies and good ( κ = .67) in corpus biopsies. The κ for the semiquantitative scoring of neutrophils was poor on the 6-point scale (∼.43) and fair on the amalgamated scale (∼.54). The interobserver agreement was the poorest in the evaluation of atrophy (presence, absence, categories, or group categories) with κ coefficients varying from .08 and .29. This group of pathologists had a high level of concordance on the diagnosis of H pylori infection in any particular patient and a high index in the assessment of the intensity of infection. The agreement was less in the semiquantitative evaluation of active inflammation. When the evaluation concerned a loosely defined feature, such as atrophy, there was essentially no agreement among the pathologists. This study suggests the need for further assessments of pathologists' ability to provide reproducible diagnoses. These results also indicate that more stringent criteria for the diagnosis of “soft” histopathologic features (such as atrophy) are urgently needed.