Are routine ancillary stains required to diagnose Helicobacter infection in gastric biopsy specimens? An institutional quality assurance review

Initial assessment of "Gissell's stain": A novel histopathological method for the identification of Helicobacter pylori

INTRODUCTION AND OBJECTIVES

The histopathological identification of Helicobacter pylori using the routine method (haematoxylin-eosin) is not only very difficult but also has low sensitivity. Giemsa staining is often used in addition, but different protocols do not produce homogeneous results. Furthermore, the Gold Standard recommended by the European Helicobacter Pylori Study Group has been applied in very few studies, thus resulting in uncertain outcomes. Therefore, a new staining method is required to overcome these limitations. The aim of this study was to evaluate the diagnostic capacity and inter-observer agreement of "Gissell's stain".

MATERIAL AND METHODS

A cross-sectional study evaluated 99 gastric paraffin blocks from a private laboratory. Three sections were prepared from each block, and haematoxylin-eosin (HE), Giemsa and "Gissell's stain" methods were applied. The kappa statistics, sensitivity, specificity, and predictive values were calculated.

RESULTS

"Gissell's stain" obtained the highest inter-observer agreement (kappa=0.87) compared to the other two methods (HE, kappa=0.51; Giemsa, kappa=0.83). It also obtained the best sensitivity and negative predictive value (97.1% and 98.3%, respectively) compared with the other two methods (HE: 68.6% and 85.1%, respectively; Giemsa: 88.6% and 93.9%, respectively).

CONCLUSIONS

Given its unique characteristics (fast, cheap, accessible, and easy to use), in addition to its statistical reliability, "Gissell's stain" has great potential for routine use in the identification of H. pylori.

The Histopathological Characteristic of Gastric Carcinoma in the Belgian Tervueren and Groenendael Dog: A Comparison of Two Classification Methods

Gastric carcinoma is generally considered to be a rare disease in dogs, carrying a grave prognosis. However, in the Tervueren and Groenendael varieties of the Belgian Shepherd dog breed, the disease is highly prevalent. While histopathology is the gold standard for diagnosing gastric carcinoma, there is no general consensus on the methods for histological classification in these cases. Biopsies of a group of 61 dogs with confirmed gastric carcinoma (45 Tervueren and 16 Groenendael) were examined and classified according to World Health Organization (WHO) and Laurén classifications. Kaplan-Meier curves were used to compare survival between the different subtypes and simple and multiple linear regression were used to analyse the association between age of onset and breed variant, sex, neuter status, location of the tumour, inflammation score, and Laurén and WHO classifications. Mean age at diagnosis was significantly different in Groenendael (10.1 ± 2.01) and Tervueren dogs (8.5 ± 1.90). The Laurén classification resulted in 29 (48%) diffuse- and 32 (52%) intestinal-type tumours. Applying the WHO classification resulted in 30 (49%) tubular carcinoma growth patterns and 31 (51%) others. Median survival time was significantly reduced for the diffuse type as compared to the intestinal type according to the Laurén classification, with the same median survival time results for tubular compared to non-tubular subtypes according to the WHO classification (median survival time of 61 vs. 182 days, respectively). Using the WHO and Lauren classification on tumour biopsies may help the practising clinician in the prognostication of gastric carcinoma in Tervueren and Groenendael dogs.

Helicobacter pylori Infection, Its Laboratory Diagnosis, and Antimicrobial Resistance: a Perspective of Clinical Relevance

Despite the recent decrease in overall prevalence of Helicobacter pylori infection, morbidity and mortality rates associated with gastric cancer remain high. The antimicrobial resistance developments and treatment failure are fueling the global burden of H. pylori-associated gastric complications. Accurate diagnosis remains the opening move for treatment and eradication of infections caused by microorganisms. Although several reports have been published on diagnostic approaches for H. pylori infection, most lack the data regarding diagnosis from a clinical perspective. Therefore, we provide an intensive, comprehensive, and updated description of the currently available diagnostic methods that can help clinicians, infection diagnosis professionals, and H. pylori researchers working on infection epidemiology to broaden their understanding and to select appropriate diagnostic methods. We also emphasize appropriate diagnostic approaches based on clinical settings (either clinical diagnosis or mass screening), patient factors (either age or other predisposing factors), and clinical factors (either upper gastrointestinal bleeding or partial gastrectomy) and appropriate methods to be considered for evaluating eradication efficacy. Furthermore, to cope with the increasing trend of antimicrobial resistance, a better understanding of its emergence and current diagnostic approaches for resistance detection remain inevitable.

Chinese Consensus Report on Family-Based Helicobacter pylori Infection Control and Management (2021 Edition)

OBJECTIVE

Helicobacter pylori infection is mostly a family-based infectious disease. To facilitate its prevention and management, a national consensus meeting was held to review current evidence and propose strategies for population-wide and family-based H. pylori infection control and management to reduce the related disease burden.

METHODS

Fifty-seven experts from 41 major universities and institutions in 20 provinces/regions of mainland China were invited to review evidence and modify statements using Delphi process and grading of recommendations assessment, development and evaluation system. The consensus level was defined as ≥80% for agreement on the proposed statements.

RESULTS

Experts discussed and modified the original 23 statements on family-based H. pylori infection transmission, control and management, and reached consensus on 16 statements. The final report consists of three parts: (1) H. pylori infection and transmission among family members, (2) prevention and management of H. pylori infection in children and elderly people within households, and (3) strategies for prevention and management of H. pylori infection for family members. In addition to the 'test-and-treat' and 'screen-and-treat' strategies, this consensus also introduced a novel third 'family-based H. pylori infection control and management' strategy to prevent its intrafamilial transmission and development of related diseases.

CONCLUSION

H. pylori is transmissible from person to person, and among family members. A family-based H. pylori prevention and eradication strategy would be a suitable approach to prevent its intra-familial transmission and related diseases. The notion and practice would be beneficial not only for Chinese residents but also valuable as a reference for other highly infected areas.

Efficacy of immunohistochemical staining in detecting <em>Helicobacter pylori</em> in Saudi patients with minimal and atypical infection

Gastric Helicobacter pylori infection is diagnosed based on histopathological evaluation of gastric mucosal biopsies, urease test, urea breath test, H. pylori culturing, or direct detection using polymerase chain reaction (PCR). This study aimed to evaluate the efficacy of immunohistochemical (IHC) staining in detecting H. pylori in gastric biopsies from patients with chronic gastritis and minimal or atypical infection. Gastric biopsies from 50 patients with chronic gastritis were subjected to routine haematoxylin and eosin (H-E), modified Giemsa, and IHC staining. The results of staining were compared with those of quantitative real-time PCR (qRT-PCR). The qRT-PCR analysis identified 32 (64%) H. pylori-positive cases, whereas IHC, H-E, and modified Giemsa staining identified 29 (58%), 27 (54%), and 21 (42%) positive cases. The sensitivity of IHC staining (87.50%) was higher than that of H-E (59.38%) and modified Giemsa (43.75%) staining. The specificity of H-E, modified Giemsa, and IHC staining was 55.56%, 61.11%, and 94.44%, respectively. IHC staining exhibited the highest diagnostic accuracy (90%), followed by H-E (58%) and modified Giemsa (50%) staining. Active gastritis, intestinal metaplasia, and lymphoid follicles were detected in 32 (64%), 4 (8%), and 22 (44%) cases, respectively, and all of these cases were H. pylori positive. In contrast to routine H-E and modified Giemsa staining, IHC allows for the accurate H. pylori detection in cases with minimal or atypical infection. Moreover, IHC can be an alternative diagnostic method to qRT-PCR for detection of H. pylori in such cases.

Objective Visual Analog Scale for Biopsy Diagnosis of Helicobacter pylori Infection in Clinical Practice

Historic and current pathology society guidelines recommend using visual gestalt to identify substantial inflammatory cell infiltrate in Helicobacter pylori gastritis, but these scales were subjectively designed. This study aims to objectively investigate the density of inflammation that justifies additional workup for H. pylori infection. We retrospectively identified 2 patient cohorts who had undergone endoscopy with gastric biopsies; 1 with H. pylori infection (n=66), confirmed with a positive stool antigen test and/or Campylobacter-like organism test, and 1 without infection (n=81). Antral and body biopsies were selected from each case, if available, and stained with MUM-1 to highlight mucosal plasma cells. Digital analysis was performed to calculate the number of plasma cells/mm2, termed the "inflammatory score" (IS). Patients with H. pylori infection had an average of 1289 plasma cells/mm2 in the antrum and 835 plasma cells/mm2 in the body, compared with 346 plasma cells/mm2 in the antrum and 178 plasma cells/mm2 in the body in patients without infection. IS cut-off values for a positive infection were 714 plasma cells/mm2 in the antrum and 316 plasma cells/mm2 in the body, with high sensitivities and specificities in both the antrum (92%, 92%) and body (85%, 84%), respectively. A visual analog scale was created to provide a histologic correlate of the observed IS ranges and cut-offs. This practical and objective scale is associated with a high sensitivity and specificity for diagnosing H. pylori infection and justifies moving away from upfront universal H. pylori testing in routine clinical practice.

Detection of Helicobacter pylori in virtual slides requires high resolution digitalisation

To diagnose Helicobacter pylori (HP) infection and its related mucosal injuries requires the histopathological analysis of gastric biopsies. The move from glass slides interpretation towards digital pathology implies technical choices to maintain the performances of histopathological diagnosis. The intra-rater agreement in assessing gastritis diagnostic criteria between glass slides, low resolution and high resolution digital slides in the subject of the present study. One hundred gastric biopsies were re-assessed by a single digestive pathologist on glass slides and digitalised slides at low resolution (ie, x20 magnification and single focus without z-stack) and high resolution (ie, x40 magnification with seven focus levels and z-stack) about the criteria of the updated Sydney system and the detection of HP. Inter-analyses agreement were very good (Kappa values>0.81) for every criteria but slightly inferior (ie, Kappa values<0.9) comparing glass slides interpretations with low resolution digital slides-based ones. Indeed, some HP infections were misdiagnosed using x20 magnification histochemical stained digitalised slides (p<0.05). At the opposite, anti-HP immunohistochemistry slides and/or x40 magnification digitalisation permitted to maintain almost perfect concordance in diagnosis (Kappa value>0.9). As mentioned in current guidelines, a high resolution x40 magnification digitalisation must be favoured in order to avoid some misdetection of microorganisms as HP.

Helicobacter pylori colonisation of duodenal foveolar metaplasia requires concurrent gastric infection

AIMS

Evaluate the rate and significance of Helicobacter pylori (H. pylori) involving duodenal foveolar metaplasia of chronic peptic duodenitis (CPD).

METHODS

We identified 100 biopsy cases of CPD with synchronous stomach biopsies. All 200 were reviewed for histological changes (eg, chronic gastritis, acute inflammation) and underwent immunohistochemical staining for H. pylori. Results were correlated with patient age, sex, endoscopy indication and findings on stomach biopsy.

RESULTS

Cases included 49 men and 51 women, with a median age of 56 years. Reflux or dysphagia was the most common symptom. Chronic gastritis was present in 46 stomach biopsies, with 54 within normal limits. Twelve stomach biopsies showed H. pylori, all of which showed gastritis. Two duodenal biopsies (2%) demonstrated H. pylori organisms on immunohistochemistry, both from patients with H. pylori gastritis.

CONCLUSIONS

Routine examination of CPD samples for H. pylori appears unnecessary if a stomach biopsy is available for review.

An Update on the Role of Immunohistochemistry in the Evaluation of Gastrointestinal Tract Disorders

As in other organ systems, immunohistochemistry (IHC) serves as an ancillary diagnostic tool for a wide variety of neoplastic and non-neoplastic disorders, including infections, work-up of inflammatory conditions, and subtyping neoplasms of the gastrointestinal (GI) tract. In addition, IHC is also used to detect a variety of prognostic and predictive molecular biomarkers for carcinomas of the GI tract. The purpose of this review is to highlight the use of IHC in common diagnostic scenarios throughout the tubular GI tract. The clinical indication and guidelines for performing IHC for detecting Helicobacter pylori is discussed along with role of gastrin and neuroendocrine markers in the diagnosis of autoimmune metaplastic atrophic gastritis. The major portion of this review discusses the use of IHC in the diagnostic workup of malignant neoplasms of the GI tract, such as adenocarcinoma versus squamous cell carcinoma, workup of poorly differentiated malignant neoplasms, and evaluation of uncommon gastric neoplasms (alpha-feto protein-producing carcinomas) and switch/sucrose-nonfermenting complex-deficient carcinomas. Lastly, localization of neuroendocrine tumors of unknown origin to aid clinical management, as well as HPV-driven anal neoplasia and IHC in the workup of basaloid anal neoplasms are also reviewed.

Detection of Helicobacter pylori with clarithromycin resistance-associated mutations using peptide nucleic acid probe-based melting point analysis

BACKGROUND

Detection of Helicobacter pylori in gastric biopsy is important for appropriate treatment and prevention of gastric carcinoma and lymphoma. A novel peptide nucleic acid probe (PNA)-based real-time polymerase chain reaction (PCR) method was developed for detection of H pylori and A2142G/A2143G mutation of the 23S rRNA gene, which is associated with clarithromycin resistance.

METHODS

To evaluate the performance of the PNA probe-based PCR method, a total of 409 gastric biopsy samples were analyzed by PNA probe-based PCR and compared with other H pylori detection methods, including hematoxylin and eosin (HE) and Warthin-Starry (WS) staining, immunohistochemistry (IHC). A2142G/A2143G mutation of the 23S rRNA gene was tested by dual priming oligonucleotide (DPO)-based PCR and Sanger sequencing to evaluate PNA probe-based PCR.

RESULTS

Among 271 cases that were positive for H pylori on IHC which was considered as a standard method, 264 cases (97.4%) and 259 cases (95.6%) were positively detected by HE/WS and PNA probe-based qPCR, respectively. Of 100 H pylori-positive patients tested by IHC, H pylori was detected in 93 cases (93.0%) by PNA probe-based PCR, 86 cases (86.0%) by DPO-based PCR, and 93 cases (93.0%) by conventional PCR. The sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of PNA probe-based qPCR were 93.0%, 94.9%, 93.9%, 94.9%, and 93.0%, respectively, which were all higher than those of DPO-based PCR. When Sanger sequencing was determined as a standard method to detect A2142G/A2143G mutations, the sensitivity of the PNA- and DPO-based methods was 100% and 94.4%, respectively, and the specificity was 100% for both methods.

CONCLUSION

PNA probe-based qPCR is an appropriate method for detecting H pylori and the clarithromycin resistance-associated mutation type.

Endoscopic features aiding the diagnosis of gastric mucosa-associated lymphoid tissue lymphoma

The incidence of gastric mucosa-associated lymphoid tissue (MALT) lymphoma is increasing worldwide, but the diagnosis is difficult. Most patients are asymptomatic or complain of nonspecific gastrointestinal symptoms. As the endoscopic features of gastric MALT lymphoma are variable and nonspecific, the possibility of this condition may be overlooked during esophagogastroduodenoscopy, and it remain undiagnosed. Therefore, this condition needs to be considered when an abnormal mucosa is observed during this procedure. Biopsy performed during endoscopy is the primary diagnostic test, but false negative results are possible; large numbers of samples should be collected from both normal and abnormal mucosae. Endoscopic ultrasonography is useful to assess the depth of invasion and to predict the treatment response. After treatment, follow-up tests are required every 3 months until complete remission is achieved, and annually thereafter. Early diagnosis of gastric MALT lymphoma is difficult, and its diagnosis and follow-up require wide experience and competent endoscopic technique.

Utilization Rate of Helicobacter pylori Immunohistochemistry Is Not Associated With the Diagnostic Rate of Helicobacter pylori Infection

BACKGROUND

Utilization rates of immunohistochemistry (IHC) for the diagnosis of Helicobacter pylori infection may vary by laboratory and/or pathologists. IHC for H. pylori is not performed routinely in our practice. Instead, it is used in selected cases at the pathologists' discretion (and according to their specific criteria). The purpose of this study was to determine if IHC utilization rates correlated with rates of detecting H. pylori infection.

MATERIALS AND METHODS

We searched our records and investigated all gastric biopsies for 1 calendar year. H. pylori diagnostic rate and IHC utilization rate was calculated for each pathologist.

RESULTS

Overall, the rate of diagnosis was 12.1% and the IHC utilization rate was 45.2%. Individual pathologists had H. pylori diagnostic rates ranging from 3.6% to 34.1% (median: 11.1%) and IHC utilization ranging from 17.1% to 95.2% (median: 42.2%). The rate of detection of H. pylori infection among pathologists showed no significant correlation with rates of IHC utilization (Pearson coefficient=0.121).

CONCLUSIONS

Increasing use of IHC is not independently associated with the diagnostic rate of infection. Ultimately, if we assume that the case mix was similar for each pathologist, it suggests that more liberal criteria to order IHC does not result in more infections diagnosed.

[Diagnosis of Helicobacter pylori Infection]

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is mandatory for the effective management of many gastroduodenal diseases. Currently, various diagnostic methods are available for detecting these infections, and the choice of method should take into account the clinical condition, accessibility, advantage, disadvantage, as well as cost-effectiveness. The diagnostic methods are divided into invasive (endoscopic-based) and non-invasive methods. Non-invasive methods included urea breath test, stool antigen test, serology, and molecular methods. Invasive methods included endoscopic imaging, rapid urease test, histology, culture, and molecular methods. In this article, we provide a review of the currently available options and recent advances of various diagnostic methods.

Warthin-Starry Staining for the Detection of Helicobacter pylori in Gastric Biopsies

Background

Warthin-Starry (WS) staining is an ancillary stain used in the detection of Helicobacter sp., spirochaete and other microorganisms in tissue sections. The present study aimed to determine the validity of WS stain in the confirmation of H. pylori diagnosis in gastric biopsies in comparison with anti-H. pylori immunohistochemistry (IHC) staining.

Methods

This study involved 104 cases of gastric biopsies that were previously subjected to WS staining. All cases involved retrieval of formalin-fixed paraffin-embedded (FFPE) gastric biopsies that were re-cut, subjected to anti-H. pylori IHC staining and reviewed blindly by a pathologist. The sensitivity, specificity, positive predictive value (PPV) and negative predictive value (NPV) of WS as compared to IHC were calculated.

Results

In this study, WS stain was less sensitive in detecting H. pylori. The sensitivity, specificity, PPV and NPV for WS stain were 50.0%, 92.4%, 79.2% and 76.3%, respectively.

Conclusions

The sensitivity of WS stain in the histopathology laboratory was lower than that described previously. Several external factors that might influence the results were identified. However, sufficient information on patients’ history of treatment and medication would be required for the diagnosis or confirmation of the presence of H. pylori in gastric biopsies by WS staining.

Diagnosis of Helicobacter pylori infection : A short review

Helicobacter pylori infections represent an important factor in the pathogenesis of chronic gastritis, peptic ulcer, MALT lymphoma and gastric adenocarcinoma. The recently published Maastricht V/Florence consensus report indicated that the urea breath test using 13 C urea still remains the best non-invasive test to diagnose H. pylori infections with high sensitivity and specificity. Among the stool antigen tests, the ELISA monoclonal antibody test is a rational option. Effective therapy should be based only on susceptibility testing in regions with documented high clarithromycin resistance (>15%). Advanced high-resolution endoscopic technologies enable increased diagnostic accuracy for detection of H. pylori infections.

Upfront immunohistochemistry improves specificity of Helicobacter pylori diagnosis. A French pathology laboratory point of view

BACKGROUND

There is no consensus about the histopathologic methods to detect Helicobacter pylori in gastric biopsies to date. We aimed to question about the value of upfront anti-H. pylori immunohistochemistry in this field.

MATERIAL AND METHODS

We led a retrospective study about the rate of H. pylori-positive gastric biopsies before and after the implementation of upfront immunohistochemistry, the inter-rater and intermethods agreements in H. pylori identification about Hematoxylin-Eosin Saffron (HES), Giemsa, and immunohistochemistry stains and the histopathologic features associated with low amounts of H. pylori.

RESULTS

First, the rate of H. pylori-positive gastric biopsies significantly diminished after the implementation of upfront immunohistochemistry (from 21.15% to 12.56%, P<.0001), suggesting potential overdiagnosis of H. pylori infection before the use of immunohistochemistry. Secondly, immunohistochemistry was the most reproducible and performing stain (kappa values >0.80), but HES and Giemsa stains also presented good-to-very good agreements. Finally, less than 1% of gastric biopsies with inconspicuous H. pylori infection showed no mucosal injury pointing out that any HES-detected mucosal injury could help to preselect the gastric biopsies requiring ancillary stains for the detection of H. pylori.

CONCLUSIONS

Albeit being considered as a gold standard in the detection of H. pylori, the interest of using immunohistochemistry as an upfront stain on gastric biopsies is still debated. In our opinion, its use in second line in case of ambiguous HE/HES-Giemsa result is more appropriate. Further effort is needed to optimize the inexpensive but feasible HE/HES-based detection of H. pylori.

Sensitivity of Helicobacter pylori detection by Giemsa staining is poor in comparison with immunohistochemistry and fluorescent in situ hybridization and strongly depends on inflammatory activity

BACKGROUND

Conventional stainings (including H&E and special stains like Giemsa) are the most widely applied histopathologic detection methods of Helicobacter pylori (HP).

MATERIALS AND METHODS

We aimed to compare the diagnostic performance of Giemsa staining with immunohistochemistry (IHC) and fluorescent in situ hybridization (FISH) on a monocentric cohort of 2896 gastric biopsies and relate results to histologic alterations in order to find such histopathologic subgroups in which these methods underperform. All cases were categorized regarding presence or absence of chronic gastritis, inflammatory activity, and mucosal structural alterations.

RESULTS

Giemsa revealed 687 cases (23.7%), IHC 795 cases (27.5%), and FISH 788 cases (27.2%) as being HP positive. Giemsa showed significantly lower overall sensitivity (83.3%) compared to IHC (98.8%) and FISH (98.0%). Moreover, the sensitivity of Giemsa dramatically dropped to 33.6% in the nonactive cases. We found that sensitivity of Giemsa strongly depends on HP density and, accordingly, on the presence of activity. Structural alterations (intestinal metaplasia, atrophy, etc.) had only no or weak effect on sensitivity of the three stainings. Both IHC and FISH proved to be equally reliable HP detecting techniques whose diagnostic performance is minimally influenced by mucosal inflammatory and structural alterations contrary to conventional stainings.

CONCLUSIONS

We highly recommend immunohistochemistry for clinically susceptible, nonactive chronic gastritis cases, if the conventional stain-based HP detection is negative. Moreover, we recommend to use IHC more widely as basic HP stain. Helicobacter pylori FISH technique is primarily recommended to determine bacterial clarithromycin resistance. Furthermore, it is another accurate diagnostic tool for HP.

Management of Helicobacter pylori infection-the Maastricht V/Florence Consensus Report

Important progress has been made in the management of Helicobacter pylori infection and in this fifth edition of the Maastricht Consensus Report, key aspects related to the clinical role of H. pylori were re-evaluated in 2015. In the Maastricht V/Florence Consensus Conference, 43 experts from 24 countries examined new data related to H. pylori in five subdivided workshops: (1) Indications/Associations, (2) Diagnosis, (3) Treatment, (4) Prevention/Public Health, (5) H. pylori and the Gastric Microbiota. The results of the individual workshops were presented to a final consensus voting that included all participants. Recommendations are provided on the basis of the best available evidence and relevance to the management of H. pylori infection in the various clinical scenarios.

Routine Anti-Helicobacter Immunohistochemical Staining is Significantly Superior to Reflex Staining Protocols for the Detection of Helicobacter in Gastric Biopsy Specimens

BACKGROUND

The role of special stains in the detection of H. pylori is controversial; some pathologists claim that hematoxylin and eosin staining alone is adequate to detect bacteria, while others maintain that immunohistochemical staining must be used on all gastric biopsies. This study was designed to test the hypothesis that hematoxylin and eosin and histochemical special stains have similar sensitivity and that immunohistochemical staining only marginally enhances the detection rate of the organisms.

MATERIALS AND METHODS

Records of all gastric biopsies examined in a large pathology laboratory between January 1, 2010 and December 31, 2014 were extracted and stratified according to the stain used for the detection of Helicobacter (1. hematoxylin and eosin only; 2. Upfront HP Blue; 3. Upfront HP Blue including reflex immunohistochemistry; 4. Upfront anti-Helicobacter immunohistochemical staining.

RESULTS

Gastric biopsies from 794,859 endoscopies obtained from 622,945 unique patients were analyzed. The basic demographics of the patients in different staining groups were identical. A total of 56,955 gastric biopsy sets were stained with histochemical stains only, and 731,193 with anti-Helicobacter immunohistochemical stain; in 4409 of these, an immunohistochemical stain was also performed. In 2302 cases, only hematoxylin and eosin were performed. In this latter group, 7.0% of patients were Helicobacter-positive; in the upfront HP Blue, the prevalence was 7.8%, whereas patients with upfront immunohistochemistry had a prevalence of 10.2% (p < .0001, compared to hematoxylin and eosin only).

CONCLUSIONS

There was a dramatic improvement in detection of H. pylori infection through the use of upfront immunohistochemical stains. Therefore, we contend that the routine use of IHC for all gastric biopsies is an appropriate protocol to ensure that every patient gets the right answer.

A Strategy for Helicobacter Immunohistochemistry Utilization in Pediatric Practice: Insights From Morphologic and Cost-Benefit Analyses

OBJECTIVES

Recent studies in adults have examined the utility of immunohistochemistry (IHC) in detecting Helicobacter in gastric biopsy specimens and reached differing conclusions. Dedicated cost-benefit analysis of Helicobacter IHC in pediatric gastric biopsy specimens has not been performed.

METHODS

From 1,955 pediatric gastric biopsies in a 1-year period, we identified 63 Helicobacter -positive and 120 Helicobacter -negative biopsy specimens. All cases were scored according to the Updated Sydney System for the severity of inflammation.

RESULTS

We observed that pediatric Helicobacter infection was significantly associated with germinal center formation, active inflammation, oxyntic mucosa with moderate to severe chronic inflammation, and antral mucosa with any chronic inflammation, exclusive of mild and superficial chronic inflammation. At least one associated pattern was seen in each Helicobacter -positive biopsy specimen. In comparison with adults, pediatric Helicobacter -positive biopsy specimens are more likely to lack acute inflammation and more likely to show moderate to marked chronic inflammation.

CONCLUSIONS

We recommend performing Helicobacter IHC on pediatric gastric biopsy specimens with any of the above inflammatory patterns. This approach can sensitively identify pediatric patients with Helicobacter gastritis, limit IHC staining to approximately 30% of all gastric biopsy specimens, and reduce costs by up to $55,306.90 per 1,000 biopsy specimens.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Factors Associated With Detection of Helicobacter pylori in Gastric Biopsies: A Case-Control Study of 396 Biopsies

AIM OF THE STUDY

Helicobacter pylori (HP) infection is associated with significant gastric mucosal inflammation. We aimed to determine the clinicopathologic features associated with HP in gastric biopsy.

METHODS AND RESULTS

Three hundred ninety-six gastric biopsies were evaluated including 165 HP-positive cases and 231 randomly selected HP-negative controls. HP was detected using hematoxylin and eosin (H&E), Giemsa, and immunohistochemistry staining. The univariate and multivariate analyses were conducted to study the relationship of clinicopathologic characteristics and HP infection. Among the HP-positive cases, 131 cases were confirmed by H&E staining and 34 cases were confirmed by Giemsa or immunohistochemistry staining. Compared with chronic inactive gastritis, chronic active gastritis was more likely associated with having HP detected by H&E. Males were more likely to have HP gastritis than females (odds ratio: 1.72, P=0.01). The patients who had chronic active gastritis or chronic gastritis (moderate or severe) were more likely to have HP infection than patients with mild chronic gastritis (P<0.001). Conversely, patients who had intestinal metaplasia were less likely to have HP infection than patients without intestinal metaplasia (odds ratio: 0.22, P<0.001). However, concurrent atrophic gastritis was not related to HP infection (P=0.37). HP infection history was not associated with HP infection (P=0.74).

CONCLUSIONS

HP detection in gastric biopsies is associated with active inflammation, male sex, and the lack of intestinal metaplasia, but not atrophic gastritis or HP infection history. Routine ancillary staining may not be required for HP detection in all biopsy specimens. We do not recommend ancillary staining for mild chronic inactive gastritis.

Secondary syphilis in HIV positive individuals: correlation with histopathologic findings, CD4 counts, and quantity of treponemes in microscopic sections

BACKGROUND

Although syphilis is uncommon, infection rates are much higher in HIV-infected individuals than the general population. A proposed explanation is impaired cellular immunity with HIV infection.

METHODS

A search of one institution yielded 10 patients with a diagnosis of secondary syphilis on skin biopsy, positive syphilis serology and available CD4 counts. We evaluated 11 biopsies from the 10 patients. We correlated the patients' CD4 counts with the histologic findings and with the number of treponemes on skin biopsies, highlighted by immunohistochemistry (IHC). We also compared the detection of spirochetes in silver stained sections (e.g. Warthin-Starry) with T. pallidum IHC. All biopsies were assessed for various histologic features.

RESULTS

The sensitivity of IHC to detect treponemes was 64% and of silver stain was 9% (p-value 0.04). The number of treponemes on the biopsies was determined by IHC. High numbers of spirochetes (i.e. >100 per 10 hpf) were only seen in patients with CD4 counts less than 250 cells/ml.

CONCLUSION

The most consistent histologic finding was a moderate to severe lymphoplasmacytic infiltrate. Although the study is small, it appears that a higher number of spirochetes is associated with CD4 counts less than 250 cell/ml. The T. pallidum IHC stain was vastly superior to the Warthin-Starry stain.

Gastric mucosa-associated lymphoid tissue lymphoma and Helicobacter pylori infection: a review of current diagnosis and management

Helicobacter pylori (H. pylori)-associated gastritis is one of the most common infectious diseases in the United States, China and worldwide. Gastric mucosa-associated tissue lymphoma (MALT lymphoma) is a rare mature B-cell neoplasm associated with H. pylori infection that is curable by antibiotics therapy alone. The pathological diagnosis of gastric MALT lymphoma can be reached by histological examination, immunohistochemical staining and B-cell clonality analysis. H. pylori eradication is the choice of therapy for early-stage gastric MALT lymphoma. High response rates and long-term survival have been reported in refractory and localized diseases treated with low-dose radiation therapy. Systemic chemotherapy is recommended for advanced-stage gastric MALT lymphoma and cases with large B-cell lymphoma transformation. Recent advances in the pathological diagnosis and management of gastric MALT lymphoma are reviewed in this article.

Helicobacter-negative gastritis: polymerase chain reaction for Helicobacter DNA is a valuable tool to elucidate the diagnosis

BACKGROUND

Helicobacter-negative gastritis has been increasingly reported. Molecular techniques as the polymerase chain reaction (PCR) may detect bacterial DNA in histologically negative gastritis.

AIM

To evaluate of Helicobacter PCR in gastric biopsies for the daily diagnostics of Helicobacter-negative gastritis.

METHODS

Over a 5-year period, routine biopsies with chronic gastritis reminiscent of Helicobacter infection, but negative by histology, were tested by using a H. pylori specific PCR. Subsequently, PCR-negative samples were re-evaluated using PCR for other Helicobacter species.

RESULTS

Of the 9184 gastric biopsies, 339 (3.7%) with histological-negative gastritis and adequate material were forwarded to PCR analysis for H. pylori and 146 (43.1%) revealed a positive result. In 193 H. pylori DNA-negative biopsies, re-analysis using PCR primers for other Helicobacter species, revealed further 23 (11.9%) positive biopsies, including 4 (2.1%) biopsies with H. heilmannii sensu lato. PCR-positive biopsies showed a higher overall inflammatory score, more lymphoid follicles/aggregates and neutrophils (P < 0.05). No Helicobacter DNA was found in control biopsies of 48 patients with neither primer set (P < 0.0001). In 274 patients with an endoscopic description, detection of H. pylori DNA was associated with ulcers and erosions (P < 0.01). Over all, in 339 histologically-negative gastric biopsies, Helicobacter DNA was detected in 169 (49.9%) samples with at least one primer set.

CONCLUSION

Molecular testing offers a sensitive and specific diagnosis to a selected group of patients, in whom adequate searches for bacteria by conventional histology have resulted in the unsatisfactory diagnosis of H. pylori-negative gastritis.

The carcinogenic liver fluke Opisthorchis viverrini is a reservoir for species of Helicobacter

There has been a strong, positive correlation between opisthorchiasis-associated cholangiocarcinoma and infection with Helicobacter. Here a rodent model of human infection with Opisthorchis viverrini was utilized to further investigate relationships of apparent co-infections with O. viverrini and H. pylori. A total of 150 hamsters were assigned to five groups: i) Control hamsters not infected with O. viverrini; ii) O. viverrini-infected hamsters; iii) non-O. viverrini infected hamsters treated with antibiotics (ABx); iv) O. viverrini-infected hamsters treated with ABx; and v) O. viverrini-infected hamsters treated both with ABx and praziquantel (PZQ). Stomach, gallbladder, liver, colonic tissue, colorectal feces and O. viverrini worms were collected and the presence of species of Helicobacter determined by PCR-based approaches. In addition, O. viverrini worms were cultured in vitro with and without ABx for four weeks, after which the presence of Helicobacter spp. was determined. In situ localization of H. pylori and Helicobacter-like species was performed using a combination of histochemistry and immunohistochemistry. The prevalence of H. pylori infection in O. viverrini-infected hamsters was significantly higher than that of O. viverrini-uninfected hamsters (p≤0.001). Interestingly, O. viverrini-infected hamsters treated with ABx and PZQ (to remove the flukes) had a significantly lower frequency of H. pylori than either O. viverrini- infected hamsters treated only with ABx or O. viverrini-infected hamsters, respectively (p≤0.001). Quantitative RT-PCR strongly confirmed the correlation between intensity H. pylori infection and the presence of liver fluke infection. In vitro, H. pylori could be detected in the O. viverrini worms cultured with ABx over four weeks. In situ localization revealed H. pylori and other Helicobacter-like bacteria in worm gut. The findings indicate that the liver fluke O. viverrini in the biliary tree of the hamsters harbors H. pylori and Helicobacter-like bacteria. Accordingly, the association between O. viverrini and H. pylori may be an obligatory mutualism.

Helicobacter Pylori Infection: Diagnostic Strategies in Primary Diagnosis and After Therapy

Accurate diagnosis of Helicobacter pylori infection pre- and post-treatment is mandatory in the current era of decreasing prevalence and increasing antibiotic resistance. The diagnostic performance of most tests is poorer in clinical situations with low bacterial density which is seen in conditions such as atrophic gastritis or intake of antisecretory and antibiotic medications. Noninvasive tests require less cost and resource but provide excellent accuracy; however, endoscopy with testing of gastric biopsy specimens is indicated where alarming symptoms are present or antibiotic susceptibility testing by culture is desired. Newer modalities such as polymerase chain reaction testing provide additional virulence and antibiotic sensitivity profiling. This article outlines new developments and the key parameters of each test, as careful selection of test modality within the clinical context is required for adequate management of infected symptomatic patients.

Diagnosis of Helicobacter pylori infection: Current options and developments

Accurate diagnosis of Helicobacter pylori (H. pylori) infection is a crucial part in the effective management of many gastroduodenal diseases. Several invasive and non-invasive diagnostic tests are available for the detection of H. pylori and each test has its usefulness and limitations in different clinical situations. Although none can be considered as a single gold standard in clinical practice, several techniques have been developed to give the more reliable results. Invasive tests are performed via endoscopic biopsy specimens and these tests include histology, culture, rapid urease test as well as molecular methods. Developments of endoscopic equipment also contribute to the real-time diagnosis of H. pylori during endoscopy. Urea breathing test and stool antigen test are most widely used non-invasive tests, whereas serology is useful in screening and epidemiological studies. Molecular methods have been used in variable specimens other than gastric mucosa. More than detection of H. pylori infection, several tests are introduced into the evaluation of virulence factors and antibiotic sensitivity of H. pylori, as well as screening precancerous lesions and gastric cancer. The aim of this article is to review the current options and novel developments of diagnostic tests and their applications in different clinical conditions or for specific purposes.

Antisecretory medication is associated with decreased Helicobacter pylori detection in gastric marginal zone lymphoma

Helicobacter pylori status influences the prognosis and management of gastric extranodal marginal zone lymphoma of mucosa-associated lymphoid tissue (MALT lymphoma), so accurate determination of H pylori status is of clinical importance. The low rate of histologic H pylori positivity among gastric MALT lymphoma cases at our institution prompted investigation for possible causes. A case series of 24 patients as having gastric MALT lymphoma (with no diffuse large B-cell component) in a tertiary care setting between 1997 and 2010 was identified, and clinical records were reviewed. Immunohistochemical staining for H pylori and BCL10 was performed. This study received institutional review board approval (protocol number M13-033). Thirty-nine percent of cases (9/23) were H pylori positive by histology, and 4 additional patients had positive serologic results; overall, 57% of cases (13/23) were positive for H pylori. Treatment with antisecretory medications was associated with a lower likelihood of histologic positivity (13% among treated patients vs 75% among untreated; P = .04). Nuclear localization of BCL10 was seen in 2 cases and was not associated with H pylori status. Antisecretory medications decrease the likelihood of histologic detection of H pylori in gastric MALT lymphoma cases. Incorporation of results of serologic or other testing is needed to ensure correct classification with respect to H pylori status.

Helicobacter infections with rare bacteria or minimal gastritis: Expecting the unexpected

BACKGROUND

The routine use of special stains for detection of Helicobacter remains controversial.

AIMS

To determine the frequency of histologically atypical Helicobacter infection.

METHODS

All gastric biopsies received at a large pathology reference laboratory over a 6-month period were stained for Helicobacter, and the histologic and clinicopathologic parameters evaluated.

RESULTS

Amongst 7663 Helicobacter-positive biopsies, 823 (10.7%) did not show typical chronic active gastritis with numerous Helicobacter organisms, and were therefore considered histologically atypical. Rare Helicobacter pylori organisms accounted for 58.0% of all atypical infections; the next most common atypical Helicobacter infection was that with minimal or no gastric inflammation (23.3% of atypical infections). Patients in these groups did not differ demographically from those with other forms of atypical or typical Helicobacter infection, although a small subgroup (6%) was more likely to have had a previously treated infection.

CONCLUSIONS

In many of these atypical infections, Helicobacter would not have been suspected based on the histologic findings alone, and would have been missed without routine special stains. Performing a sensitive stain could prevent additional testing and allow prompt treatment of the affected patients, thus substantially reducing the risk for peptic ulcer and gastric cancer and preventing the transmission of the infection to family members.

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

OBJECTIVES

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.

METHODS

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.

RESULTS

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.

CONCLUSIONS

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.

Helicobacter pylori infection - recent developments in diagnosis

Considering the recommended indications for Helicobacter pylori (H. pylori) eradication therapy and the broad spectrum of available diagnostic methods, a reliable diagnosis is mandatory both before and after eradication therapy. Only highly accurate tests should be used in clinical practice, and the sensitivity and specificity of an adequate test should exceed 90%. The choice of tests should take into account clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy and the availability of the tests. This review concerns some of the most recent developments in diagnostic methods of H. pylori infection, namely the contribution of novel endoscopic evaluation methodologies for the diagnosis of H. pylori infection, such as magnifying endoscopy techniques and chromoendoscopy. In addition, the diagnostic contribution of histology and the urea breath test was explored recently in specific clinical settings and patient groups. Recent studies recommend enhancing the number of biopsy fragments for the rapid urease test. Bacterial culture from the gastric biopsy is the gold standard technique, and is recommended for antibiotic susceptibility test. Serology is used for initial screening and the stool antigen test is particularly used when the urea breath test is not available, while molecular methods have gained attention mostly for detecting antibiotic resistance.

Appropriate use of special stains for identifying Helicobacter pylori: Recommendations from the Rodger C. Haggitt Gastrointestinal Pathology Society

Helicobacter pylori is a major cause of gastroduodenal injury, gastric cancer, and lymphoma, and, thus, there is great interest in its detection and eradication. Several detection methods are available, including histochemical and immunohistochemical stains. Application of these stains in clinical practice is heterogenous, to say the least. Although they were developed to enhance H. pylori detection, changing practice models, financial considerations, and a perceived need for rapid case turnaround have led to their widespread use in routine staining studies ordered reflexively on all gastric biopsies. Emerging data suggest that most of these stains are not needed to establish a diagnosis of H. pylori infection, and their added value when biopsies show minimal, or no, inflammation is not clear. In this manuscript, the Rodger C. Haggitt Gastrointestinal Pathology Society puts forth recommendations regarding ancillary stain usage for H. pylori detection based upon critical literature review and collective experience. Pathologists rarely, if ever, detect H. pylori in "normal" biopsies, but readily observe them in optimally stained hematoxylin and eosin sections from infected patients. Therefore, we suggest that use of ancillary stains is appropriate when biopsies show chronic, or chronic active, gastritis without detectable H. pylori in hematoxylin and eosin-stained sections, but performing them "up front" on all gastric biopsies is generally unnecessary. Application of these stains to nongastric biopsies and polyps is appropriate in an extremely limited set of circumstances. It is our hope that recommendations provided herein will provide helpful information to gastroenterologists, pathologists, and others involved in the evaluation of patients for possible H. pylori infection.

The immunohistochemistry and toluidine blue roles for Helicobacter pylori detection in patients with gastritis

BACKGROUND

Helicobacter pylori, which is associated with many upper gastrointestinal diseases, is found in half of the population of the world. Several special stains and immunohistochemistry stain for H. pylori are available. The need for and usefulness of immunohistochemical (IHC) technique has been debated for years. Toluidine blue is a simple stain for microbiological studies and is easily available in laboratories. Therefore, this study was conducted to compare hematoxylin and eosin (H&E), Giemsa and toluidine blue staining with immunehistochemistry for detection of H. pylori in patients with gastritis and also to correlate the results of these staining methods with pathological grading.

METHODS

We reviewed 54 consecutive gastric biopsy specimens stained by H&E and Giemsa as well as by toluidine blue and immunohistochemistry stains for H. pylori.

RESULTS

H. pylori was positively identified by IHC in 43 (79.63%) patients, while positive samples were found in 18 (33.33%), 24 (44.44%) and 33 (61.11%) patients using H&E, Giemsa and toluidine blue staining methods. Our results showed that classical histological staining methods are not sensitive enough to identify low numbers or coccoid forms of organism, while toluidine blue and immunohistochemistry play an important role in detection of H. pylori infection.

CONCLUSION

Toluidine blue has been proved to be much more reliable than H&E and Giemsa in detection of H. pylori. In addition, in post treatment biopsies and in biopsies with unexplained chronic active gastritis without histological evidence of H. pylori should have immunohistochemistry done to detect possible low density or coccoid form of organisms.

Pathology of gastric cancer and its precursor lesions

Gastric cancers are a histologically heterogenous group of neoplasms arising from unique epidemiologic and molecular backgrounds. There is accumulating evidence that the intestinal type of gastric adenocarcinoma develops through a multistep process beginning with chronic gastritis triggered primarily by Helicobacter pylori and progressing through atrophy, intestinal metaplasia, and dysplasia (intraepithelial neoplasia) to carcinoma. Loss of E-cadherin expression resulting from CDH1 gene alterations is the primary carcinogenetic event in hereditary diffuse gastric cancer. Proximal gastric adenocarcinomas likely result from either gastroesophageal reflux or H pylori gastritis. This article provides an update of the histologic, immunohistochemical, and molecular pathways of gastric cancer and its precursors.