Low prevalence of latently Epstein-Barr virus-infected cells in chronic gastritis

Epstein-Barr virus associated gastric dysplasia: a new rare entity?

Epstein-Barr virus (EBV) infection characterizes a portion of gastric adenocarcinomas. However, since there is lack of evidence of EBV presence in pre-neoplastic lesions of gastric mucosa, the etiologic role of EBV in gastric carcinogenesis is still debated. We report an unusual case of an EBV-associated foveolar gastric dysplasia associated with a focus of EBV-positive low-grade tubular adenocarcinoma, arisen in the context of a lymphocytic-like (EBV-positive) gastritis. The present case offers the unique opportunity to determine whether EBV is an early or late event in gastric cancer development and to evaluate its prevalence in patients with gastric dysplasia. To properly address this question, we investigated EBER expression in a large mono-institutional series of gastric and gastro-esophageal cancers (n = 594) and associated precursor lesions (n = 84). All the selected gastric dysplastic lesions (n = 43) resulted EBV negative. In most cases, EBV is present only in gastric and gastroesophageal junction adenocarcinomas, but not in their precursor lesions. However, the reported case indicates that non-conventional EBV-associated dysplasia may represent a novel histopathological entity in the gastric dysplasia scenario and that EBV could play an early direct role in gastric carcinogenesis.

Epstein-Barr Virus-Associated Gastric Cancer: Old Entity with New Relevance

Gastric cancer (GC) represents a major public health issue worldwide, being the fifth most common cancer and one of the leading causes of death by cancer. In 2014, The Cancer Genome Atlas (TCGA) established that tumors positive for Epstein-Barr virus (EBV) are considered a specific subtype of GC (EBVaGC). Several meta-analyses have shown that EBVaGC represents almost 10% of all gastric cancer worldwide, with small differences in the geographic distribution. This tumor subtype has a high potential of being clinically relevant and studies have shown that it has specific features, a better prognosis, and increased overall survival. In this review, we summarize some of the most frequent aspects of EBVaGC, including the specific features of this GC subtype, data regarding the potential steps of EBVaGC carcinogenesis, and perspectives on treatment opportunities.

Epstein-Barr virus infection in patients with chronic gastritis without Helicobacter pylori infection

BACKGROUND/AIMS

The association of Epstein-Barr virus (EBV) with gastric malignancies has been proven by many studies in the literature. However, information about EBV-associated inflammation/gastritis remains limited. The aim of this study is to establish the prevalence of latent EBV infection in patients with chronic gastritis without H. pylori infection.

MATERIALS AND METHODS

In this study, 119 patients with gastritis without H. pylori infection were included. Furthermore, 28 patients with H. pylori gastritis were included in the study as a control group. Chromogenic in situ hybridization (EBV-encoded RNA) and immunohistochemistry (LMP-1 antibody) were performed in all 147 cases. The prevalence of EBV and its relationship with age, sex, the affected part of the stomach, the density of inflammation, inflammatory activity, intestinal metaplasia, and atrophy were analyzed.

RESULTS

In this study, 14 cases showed positive immunostaining for EBV. EBV positivity was seen mostly in the lymphoid tissue (13 cases), but it was also detected at the gastric epithelium (7 cases). The mean age of the patients was 44 years, which was slightly younger than that of the EBV-negative cases (48 years). The inflammation density was higher in EBV-positive cases than the EBV-negative gastritis cases (p=0.002). Intestinal metaplasia was detected in 7% of the cases. EBV-positive cases had a higher incidence of atrophy without intestinal metaplasia (21% vs 3.8% without EBV).

CONCLUSION

EBV was detected in 12% of the cases with gastritis without H. pylori infection. Endoscopic follow-up may be appropriate for patients with gastritis, who have atrophy without intestinal metaplasia and are H. pylori negative but EBV positive.

Epstein-Barr virus is absent in gastric superficial neoplastic lesions

Epstein-Barr virus (EBV) has been associated with about 9% of all gastric carcinomas, but its role in gastric carcinogenesis remains unclear since there is lack of evidence of EBV presence in pre-neoplastic lesions of gastric mucosa. This study intends to determine the prevalence of EBV in gastric dysplasia and superficial neoplasia to clarify whether EBV infection is an early or late event in gastric cancer development. This retrospective study included a total of 242 gastric lesions from 199 consecutive patients who were referred for endoscopic resection. The histological classification of lesions includes 137 low- and high-grade dysplasia and 105 superficial carcinomas. EBV infection was investigated by EBER-ISH. Results showed that EBV was not detected in any epithelial cells of any case with dysplasia or superficial carcinomas, although we observed the presence of a small number of EBV-infected lymphocytes in 2.1% of all lesions. These results showed that EBV is not present in gastric dysplasia neither in superficial carcinomas suggesting that EBV carcinogenesis is a late event in well/moderately differentiated gastric carcinogenesis.

EBV down-regulates COX-2 expression via TRAF2 and ERK signal pathway in EBV-associated gastric cancer

Epstein-Barr virus-associated gastric cancer (EBVaGC) accounts for nearly 10% of gastric cancer. Cyclooxygenase-2 (COX-2) plays a crucial role in cancer progression. However, there is no experimental study on the regulation mechanism of EBV on COX-2 in EBVaGC. To understand more about the tumorigenic mechanism of EBVaGC, the study investigated the role of EBV encode latent membrane protein LMP1 and LMP2A in the regulation of COX-2. The expression of COX-2 was examined in EBVaGC and EBV negative gastric cancer (EBVnGC) cell lines. The plasmids were transfected in SGC7901 to overexpress LMP1/2A. Small interfering RNA (si-RNA) targeting LMP1/2A in GT38 and targeting TRAF2 in SGC7901 were used to detect the expression of COX-2. Furthermore, si-ERK1/2 and the MEK inhibitor PD0325901 were used to investigate whether p-ERK participate in the regulation of COX-2 in SGC7901. The overexpression of LMP1 or LMP2A in SGC7901 down-regulates both COX-2 and TRAF2 expression, and knockdown of LMP1 or LMP2A in GT38 resulted in a certain recovery of COX-2 and TRAF2 expression. Moreover, si-TRAF2 indicated that a sharp down-regulation of COX-2. And the decrease of p-ERK also mediates the inhibitory effect of LMP1 on COX-2. In summary, overexpression of LMP1 and LMP2A inhibits COX-2, which is mediated by a decrease of TRAF2, and p-ERK is involved in the inhibition of COX-2 by LMP1 in gastric cancer.

Acute gastritis caused by concurrent infection with Epstein-Barr virus and cytomegalovirus in an immunocompetent adult

Herein, we describe an extremely rare case of gastritis due to concurrent infection with Epstein-Barr virus (EBV) and cytomegalovirus (CMV) occurring in an immunocompetent adult. The patient was a 35-year-old man who presented with slight fever, nausea, anorexia, weight loss for 3 weeks, mild transaminitis, and leukocytosis with atypical lymphocytes in peripheral blood. The clinical presentation and elevated IgM titers to both EBV-VCA and CMV strongly suggested infectious mononucleosis syndrome caused by co-infection with EBV and CMV. A computed tomographic scan of the abdomen showed diffuse thickening of the gastric wall mimicking linitis plastica, and upper endoscopy revealed thickened and eroded mucosa throughout the stomach. Histologic examination of gastric biopsies showed a dense lymphoid and neutrophilic infiltrate in the lamina propria with erosion. In situ hybridization assay revealed many lymphocytes positive for EBV-encoded RNA. Moreover, immunohistochemistry using an anti-CMV monoclonal antibody identified some CMV-positive cells (i.e. foveolar epithelium and endothelium). We finally diagnosed this case as gastric involvement in infectious mononucleosis, and the patient recovered without the administration of antiviral drugs. To our knowledge, this is the first reported case of gastritis co-infected with EBV and CMV, as a manifestation of infectious mononucleosis in an immunocompetent adult.

Case–control study of Epstein–Barr virus and Helicobacter pylori serology in Latin American patients with gastric disease

Background:

Chronic tissue damage induced by Helicobacter pylori (HP)-driven inflammation is considered the main risk of gastric carcinoma (GC). Epstein–Barr virus (EBV) infection has also been associated with GC. In this study, we aim to address the role of EBV in inflammatory GC precursor lesions and its added risk to HP infection.

Methods:

Antibodies against EBV, HP and the bacterial virulence factor CagA were measured in sera from 525 Mexican and Paraguayan patients with gastric disease. Gastric samples were characterised according to the updated Sydney classification and associations were estimated between antibody responses and severity of both tissue damage and inflammation.

Results:

We found significant associations (odd ratios and trends) between EBV and HP copositivity and premalignant lesions and intestinal-type GC. The EBV and HP coinfection was also significantly associated with increased infiltration of immune cells. No association was found between EBV and the less inflammation-driven diffuse-type GC.

Conclusions:

Our study suggests that EBV co-participates with HP to induce severe inflammation, increasing the risk of progression to intestinal-type GC.

Evidence of Epstein-Barr virus association with gastric cancer and non-atrophic gastritis

Different lines of evidence support an association between Epstein-Barr virus (EBV) and gastric cancer (GC). The main understood risk factor to develop GC is infection by Helicobacter pylori (H. pylori), which triggers a local inflammatory response critical for progression from gastritis to GC. The role of EBV in early inflammatory gastric lesions has been poorly studied. A recent study proposed a cutoff value of 2000 EBV particles to identify patients with increased chances of infection of the gastric epithelium, which may favor the inflammatory process. To better understand the role of EBV in cancer progression, we analyzed 75 samples of GC, 147 control samples of non-tumor gastric tissue derived from GC patients and 75 biopsies from patients with non-atrophic gastritis (NAG). A first-round PCR was used for EBV detection in tumor and non-tumor controls and a more sensitive nested PCR for gastritis samples; both PCRs had lower detection limits above the proposed cutoff value. With this strategy 10.67% of GC, 1.3% of non-tumor controls and 8% of gastritis samples were found positive. An EBER1 in situ hybridization showed EBV infection of epithelial cells in GC and in a third of NAG samples, while in the other NAGs infection was restricted to the mononuclear cell infiltrate. EBV-positive GCs were enriched in lace and cribriform patterns, while these rare patterns were not observed in EBV negative samples. Our results support a role for EBV in GC and early precursor lesions, either as directly oncogenic infecting epithelial cells or indirectly as an inflammatory trigger.

Expression profile of latent and lytic transcripts of epstein-barr virus in patients with gastroduodenal diseases: a study from northern India

Epstein-Barr virus (EBV) has been shown to be associated with gastric cancer. However, inconsistent findings have been reported regarding the EBV reactivation in gastric cancer and non-carcinomatous gastric epithelium. Therefore, the aim of the study was to investigate the effect of clinicopathological findings on the expression of different transcripts of EBV in patients with gastric cancer, peptic ulcer, and dyspepsia. A total of 200 adult patients (dyspepsia [120], peptic ulcer [30], gastric cancer [50]) undergoing upper gastrointestinal endoscopy were enrolled. EBV infection was diagnosed with non-polymorphic Epstein-Barr nuclear antigen1 (EBNA1) gene based PCR and confirmed by real-time PCR. The transcripts of EBV were detected by real-time RT-PCR. In patients with gastric cancer and peptic ulcer, EBV DNA was detected more often than in those with dyspepsia (P < 0.05). EBNA1 transcript was detected in all EBV positive cases and its expression was neither associated with disease nor with histopathological findings. The expression of BZLF1 was significantly associated with gastric cancer and peptic ulcer compared to dyspepsia (P < 0.01). BZLF1 expression was also found to be higher in Helicobacter pylori infected patients (P = 0.058). Expression of BARF1 and BcLF1 were significantly higher in gastric epithelium of patients having severe grade chronic inflammation (P = 0.05) and gastric atrophy (P = 0.02), respectively. In conclusion, increased expression of lytic transcripts in patients with gastric cancer, peptic ulcer, gastric atrophy, chronic inflammation and H. pylori infection suggests the association of these factors with EBV reactivation.

Epstein-Barr virus infection is common in inflamed gastrointestinal mucosa

BACKGROUND AND AIMS

Epstein-Barr virus (EBV) is present in the malignant epithelial cells of 10% of all gastric adenocarcinomas; however, localization of the virus in normal gastrointestinal mucosa is largely unexplored. In the present study, we measured EBV DNA and localized viral gene products in gastritis specimens (n = 89), normal gastric and colonic mucosa (n = 14), Crohn's disease (n = 9), and ulcerative colitis (n = 11) tissues.

METHODS

A battery of sensitive and specific quantitative polymerase chain reactions targeted six disparate regions of the EBV genome: BamH1 W, EBNA1, LMP1, LMP2, BZLF1, and EBER1. EBV infection was localized by EBV-encoded RNA (EBER) in situ hybridization and by immunohistochemical stains for viral latent proteins LMP1 and LMP2 and for viral lytic proteins BMRF1 and BZLF1. B lymphocytes were identified using CD20 immunostains.

RESULTS

EBV DNA was essentially undetectable in normal gastric mucosa but was present in 46% of gastritis lesions, 44% of normal colonic mucosa, 55% of Crohn's disease, and 64% of ulcerative colitis samples. Levels of EBV DNA exceeded what would be expected based on the numbers of B lymphocytes in inflamed tissues, suggesting that EBV is preferentially localized to inflammatory gastrointestinal lesions. Histochemical staining revealed EBER expression in lymphoid cells of some PCR-positive lesions. The viral lytic viral proteins, BMRF1 and BZLF1, were expressed in lymphoid cells of two ulcerative colitis tissues, both of which had relatively high viral loads by quantitative PCR.

CONCLUSION

EBV-infected lymphocytes are frequently present in inflamed gastric and colonic mucosa. Active viral replication in some lesions raises the possibility of virus-related perpetuation of gastrointestinal inflammation.

High levels of Epstein-Barr virus DNA in latently infected gastric adenocarcinoma

Gastric adenocarcinoma is the second leading cause of cancer death worldwide. Epstein-Barr virus (EBV) is present in the malignant cells of approximately 10% of cases. It is unclear whether EBV is being missed in some gastric adenocarcinomas due to insensitive test methods or partial EBV genome loss. In this study, we screened 113 gastric adenocarcinomas from low- and high-incidence regions (United States and Central America) for the presence of EBV using a battery quantitative real-time PCR (Q-PCR) assays targeting disparate segments of the EBV genome (BamH1W, EBNA1, LMP1, LMP2, BZLF1, EBER1) and histochemical stains targeting EBV-encoded RNA (EBER), the latent proteins LMP1 and LMP2, and the lytic proteins BMRF1 and BZLF1. EBV DNA was detected by Q-PCR in 48/75 United States cancers (64%) and in 38/38 Central American cancers (100%), which was a significant difference. EBER was localized to malignant epithelial cells in 8/48 (17%) United States and 3/38 (8%) Central American cancers. Viral loads were considerably higher for EBER-positive vs EBER-negative cancers (mean 162 986 vs 62 EBV DNA copies per 100,000 cells). A viral load of 2000 copies per 100,000 cells is recommended as the threshold distinguishing EBER-positive from EBER-negative tumors. One infected cancer selectively failed to amplify the LMP2 gene because of a point mutation, whereas another cancer had an atypical pattern of Q-PCR positivity suggesting deletion of large segments of the EBV genome. Three different viral latency profiles were observed in the cancers based on constant expression of EBER and focal or variable expression of LMP1 or LMP2, without lytic protein expression. We conclude that EBV DNA levels generally reflect EBER status, and a panel of at least two Q-PCR assays is recommended for sensitive identification of infected cancers.

Epstein-Barr Virus Gastritis

We describe an exceedingly rare case of severe gastritis that was temporally associated with primary Epstein-Barr virus (EBV) infection. The patient was a 59-year-old immunocompetent man who presented with intermittent fever of unknown origin and epigastric pain for 18 days. A computed tomographic scan of the abdomen showed diffuse thickening of the gastric wall and esophagogastroduodenoscopy revealed numerous ulcers in the stomach. Histologic examination of gastric biopsies showed a dense and diffuse atypical lymphoid infiltrate in the lamina propria with erosions and focal lymphoepithelial lesions. No lymphoid follicles or Helicobacter microorganisms were identified. Immunohistochemical studies demonstrated the lymphoid infiltrate to consist of mixed T and B cells. Immunoglobulin heavy chain gene arrangement analysis showed a polyclonal pattern. The plasma cells present in the biopsies exhibited no light chain restriction as determined by in situ hybridization. Concurrent clinical work-up revealed peripheral lymphocytosis with atypical lymphocytes and positive serum IgM antibody to EBV capsid antigen in the absence of IgG antibody. These findings indicated that the gastric abnormalities were related to primary EBV infection as the predominant manifestation of infectious mononucleosis. This was further confirmed by subsequent in situ hybridization showing numerous EBV-positive lymphocytes in the gastric mucosa. The patient's symptoms were spontaneously resolved with only supportive treatment. A follow-up endoscopy 2 months later showed completely normal gastric mucosa and he remained well with no gastrointestinal complaints for 2 and a half years. This case illustrates the importance of a high index of suspicion to avoid misdiagnosis of gastric lymphoma that requires more aggressive therapies.