Human cytomegalovirus and Epstein-Barr virus infection in inflammatory bowel disease: Need for mucosal viral load measurement

Cytomegalovirus Infection in Adult Patients with Inflammatory Bowel Disease: A Literature Review

Human cytomegalovirus (HCMV) is classified within the Herpesvirales order and is prevalent in 50%‒80% of the general population. Most carriers experience this infection without noticeable clinical symptoms. HCMV causes a lifelong latent infection that can be reactivated due to immune disorders and inflammation. The reactivation of HCMV becomes particularly significant when it coincides with inflammatory bowel disease (IBD). While cytomegalovirus (CMV) colitis in IBD patients was identified years ago, the role of CMV in triggering flare-ups, acute severe colitis, treatment resistance, and other outcomes in IBD patients experiencing CMV reactivation remains a subject of ongoing debate. In this review, we aim to address an updated insight into aspects related to the CMV colitis in IBD patients including epidemiology, risk factors, clinical features, diagnostic tests, histology, place of immunosuppressants and indications for antiviral treatment. We suggest for personalized and thorough assessment based on the disease phase and colitis severity when prescribing drugs to these patients. Furthermore, we emphasize the importance of regular patient follow-up to monitor drug side effects, ensuring treatment success, and minimizing the risk of colectomy.

The role of Epstein-Barr virus in autoimmune and autoinflammatory diseases

Epstein-Barr Virus (EBV), a dsDNA herpesvirus, is believed to play a significant role in exacerbating and potentially triggering autoimmune and autoinflammatory maladies. Around 90% of the world is infected with the virus, which establishes latency within lymphocytes. EBV is also known to cause infectious mononucleosis, a self-limited flu-like illness, in adolescents. EBV is often reactivated and it employs several mechanisms of evading the host immune system. It has also been implicated in inducing host immune dysfunction potentially resulting in exacerbation or triggering of inflammatory processes. EBV has therefore been linked to a number of autoimmune diseases, including systemic lupus erythematosus, multiple sclerosis, rheumatoid arthritis, and Sjögren's syndrome. The review examines the molecular mechanisms through which the virus alters host immune system components thus possibly resulting in autoimmune processes. Understanding the mechanisms underpinning EBV-associated autoimmunity is pivotal; however, the precise causal pathways remain elusive. Research on therapeutic agents and vaccines for EBV has been stagnant for a long number of years until recent advances shed light on potential therapeutic targets. The implications of EBV in autoimmunity underscore the importance of developing targeted therapeutic strategies and, potentially, vaccines to mitigate the autoimmune burden associated with this ubiquitous virus.

Cytomegalovirus Infection: An Underrated Target in Inflammatory Bowel Disease Treatment

CMV infection is still a matter of concern in IBD patients, especially regarding the disease's relapse management. Why IBD patients, particularly those affected by ulcerative colitis, are more susceptible to CMV reactivation is not totally explained, although a weakened immune system could be the reason. Various techniques, ranging from serology to histology, can be employed to detect intestinal CMV infection; however, there is currently disagreement in the literature regarding the most effective diagnostic test. Furthermore, CMV involvement in steroid resistance has been broadly discussed, but whether CMV infection is a cause or consequence of the disease severity and, consequently, steroid refractoriness is still debated. Its potential contribution to the lack of response to advanced therapy and small molecules must be more valued and wholly explored. In this review, we look at the actual literature on CMV in IBD patients, and we suggest a pragmatic algorithm for clinical practice management of CMV infection.

Protective role of flavonoids quercetin and silymarin in the viral-associated inflammatory bowel disease: an updated review

Inflammatory bowel disease (IBD) is a chronic recurrent inflammation of the gastrointestinal tract (GIT). IBD patients are susceptible to various infections such as viral infections due to the long-term consumption of immunosuppressive drugs and biologics. The antiviral and IBD protective traits of flavonoids have not been entirely investigated. This study objective included an overview of the protective role of flavonoids quercetin and silymarin in viral-associated IBD. Several viral agents such as cytomegalovirus (CMV), Epstein-Barr virus (EBV), varicella zoster virus (VZV) and enteric viruses can be reactivated and thus develop or exacerbate the IBD conditions or eventually facilitate the disease remission. Flavonoids such as quercetin and silymarin are non-toxic and safe bioactive compounds with remarkable anti-oxidant, anti-inflammatory and anti-viral effects. Mechanisms of anti-inflammatory and antiviral effects of silymarin and quercetin mainly include immune modulation and inhibition of caspase enzymes, viral binding and replication, RNA synthesis, viral proteases and viral assembly. In the nutraceutical sector, natural flavonoids low bioavailability and solubility necessitate the application of delivery systems to enhance their efficacy. This review study provided an updated understanding of the protective role of quercetin and silymarin against viral-associated IBD.

Positive correlation between latent Epstein-Barr virus infection and severity of illness in inflammatory bowel disease patients

BACKGROUND

Emerging studies indicate the critical involvement of microorganisms, such as Epstein-Barr virus (EBV), in the pathogenesis of inflammatory bowel disease (IBD). Immunosuppressive therapies for IBD can reactivate latent EBV, complicating the clinical course of IBD. Moreover, the clinical significance of EBV expression in B lymphocytes derived from IBD patients’ intestinal tissues has not been explored in detail.

AIM

To explore the clinical significance of latent EBV infection in IBD patients.

METHODS

Latent EBV infection was determined by double staining for EBV encoded RNA and CD20 in colon specimens of 43 IBD patients who underwent bowel resection. Based on the staining results, the patients were divided into two groups, according to their latent EBV infection states - negative (n = 33) and positive (n = 10). Illness severity of IBD were assigned according to Crohn’s disease activity index (ulcerative colitis) and Mayo staging system (Crohn’s disease). The clinic-pathological data were analyzed between the two different latent EBV groups and also between the mild-to-moderate and severe disease groups.

RESULTS

Systolic pressure (P = 0.005), variety of disease (P = 0.005), the severity of illness (P = 0.002), and pre-op corticosteroids (P = 0.025) were significantly different between the EBV-negative and EBV-positive groups. Systolic pressure (P = 0.001), variety of disease (P = 0.000), pre-op corticosteroids (P = 0.011) and EBV infection (P = 0.003) were significantly different between the mild-to-moderate and severe disease groups.

CONCLUSION

IBD patients with latent EBV infection may manifest more severe illnesses. It is suggested that the role of EBV in IBD development should be further investigated, latent EBV infection in patients with serious IBD should be closely monitored, and therapeutic course should be optimized.

Personalize, participate, predict, and prevent: 4Ps in inflammatory bowel disease

Inflammatory bowel disease (IBD), which includes Crohn's disease (CD) and ulcerative colitis (UC), is a complex, immune-mediated, disorder which leads to several gastrointestinal and systemic manifestations determining a poor quality of life, disability, and other negative health outcomes. Our knowledge of this condition has greatly improved over the last few decades, and a comprehensive management should take into account both biological (i.e., disease-related, patient-related) and non-biological (i.e., socioeconomic, cultural, environmental, behavioral) factors which contribute to the disease phenotype. From this point of view, the so called 4P medicine framework, including personalization, prediction, prevention, and participation could be useful for tailoring ad hoc interventions in IBD patients. In this review, we discuss the cutting-edge issues regarding personalization in special settings (i.e., pregnancy, oncology, infectious diseases), patient participation (i.e., how to communicate, disability, tackling stigma and resilience, quality of care), disease prediction (i.e., faecal markers, response to treatments), and prevention (i.e., dysplasia through endoscopy, infections through vaccinations, and post-surgical recurrence). Finally, we provide an outlook discussing the unmet needs for implementing this conceptual framework in clinical practice.

Therapy Used to Promote Disease Remission Targeting Gut Dysbiosis, in UC Patients with Active Disease

Ulcerative colitis (UC) is a relapsing non-transmural chronic inflammatory disease of the colon characterized by bloody diarrhea. The etiology of UC is unknown. The goal is to reduce the inflammation and induce disease remission in UC patients with active disease. The aim of this study is to investigate the innovative treatment method used to promote disease remission in UC patients with active disease targeting gut dysbiosis. Immunosuppressants such as TNF-α blocker are used to promote disease remission in UC, but it is expensive and with side effects. Probiotic, prebiotic and diet are shown to be effective in maintaining disease remission. Fecal microbiota transplantation (FMT) might be the future therapy option to promote disease remission in UC patients with active disease. However, correct manufacturing and administration of the FMT are essential to achieve successful outcome. A few cohorts with FMT capsules show promising results in UC patients with active disease. However, randomized controlled clinical trials with long-term treatment and follow-up periods are necessary to show FMT capsules' efficacy to promote disease remission in UC patients.

Impact of Epstein-Barr virus infection in patients with inflammatory bowel disease

A high prevalence of Epstein-Barr virus (EBV) infection in patients with inflammatory bowel disease (IBD) has been reported in many case reports and studies; thus, the association between EBV and IBD has gained increasing attention. Patients with IBD are at an increased risk of opportunistic EBV infection owing to the common use of immunomodulators. EBV infection in IBD patients can cause various complications, including superimposed viral colitis, which is associated with chronicity, exacerbation, and poor prognosis of refractory IBD, and can induce progression to lymphoproliferative disorders, such as EBV-positive mucocutaneous ulcer (EBVMCU), lymphomatoid granulomatosis (LYG), hemophagocytic lymphohistiocytosis (HLH) and diffuse large B-cell lymphoma (DLBCL). It has been suggested to screen for EBV before initiating immunosuppressive therapy and monitor the status of EBV infection in patients with IBD, especially those who are EBV-seronegative and have a risk of primary EBV infection. Clinicians should also be careful of misdiagnosing IBD and EBV-associated lymphoproliferative diseases due to similarities in both clinical symptoms and endoscopic manifestations. Withdrawal of immunosuppressants has been shown to be an effective strategy to achieve remission of disease at the time of EBV diagnosis, but antiviral therapy remains controversial. The present review aims to describe the characteristics of the complications caused by EBV infection and generalize the recent research progress on and challenges caused by EBV infection in IBD patients. The literature for writing this review was collected from 'PubMed' research engine. The keywords 'inflammatory bowel disease and Epstein-Barr virus' or 'ulcerative colitis and Epstein-Barr virus' or 'Crohn's disease and Epstein-Barr virus' were used to collect the literature and relevant papers were collected to help writing this review.

Epstein-Barr Virus and Human Cytomegalovirus Infection in Intestinal Mucosa of Chinese Patients With Inflammatory Bowel Disease

Objective

This study aimed to determine the frequency of Epstein–Barr virus (EBV), cytomegalovirus (CMV) in mucosa and blood of inflammatory bowel disease (IBD) patients in China and evaluate their correlation with the clinical disease activities.

Methods

Peripheral blood and endoscopic fresh colonic mucosal samples were collected from a cohort of 287 IBD patients and 50 controls. Viral DNA load was analyzed through quantitative real-time PCR. The clinical disease activity of ulcerative colitis (UC) and Crohn’s disease (CD) was assessed by the Mayo Clinic Score and Crohn’s disease activity index, respectively.

Results

Among 287 IBD patients, 228 (79.4%) were positive for EBV and 99 (34.5%) were positive for CMV. EBV and CMV infection rates are significantly higher than those in the control group (28.0%, p < 0.05; 4.0%, p < 0.05). In addition, EBV/CMV prevalence increases as clinical activities progress [For EBV infection, the prevalence was 53.93% (48/89) in the mild group, 87.00% (87/100) in the moderate group, and 94.90% (93/98) in the severe group; and for CMV infection, the prevalence was 3.37% (3/89) in the mild group, 27.00% (27/100) in the moderate group, and 70.41% (69/98) in the severe group]. EBV and CMV loads are related to clinical disease activities (p < 0.05). In addition, viral load in the intestinal mucosa of patients with acute exacerbation of IBD is higher than that of patients in remission.

Conclusion

High prevalence of EBV and CMV is found in patients with IBD, and their prevalence is related to clinical disease activities. In addition, the viral load in the intestinal mucosa is associated with the status of mucosa in the same patients (active phase versus remission phase). Detection of viral load on mucosal specimens with quantitative real-time PCR is a feasible method to monitor EBV and CMV infection in IBD patients.

Chronic active Epstein-Barr virus enteritis: A literature review

Chronic active Epstein-Barr virus (CAEBV) enteritis is a rare disease that has not been well described. Owing to the similarities between CAEBV enteritis and inflammatory bowel diseases such as ulcerative colitis and Crohn's disease, it is easy to be misdiagnosed and mistreated in clinical practice, resulted in complications and even death in severe cases. Through a literature review, this study aimed to summarize the clinical characteristics, pathological features, examinations, and treatment strategies of CAEBV enteritis and its similarities and differences with inflammatory bowel diseases.

Cytomegalovirus in ulcerative colitis: an evidence-based approach to diagnosis and treatment

INTRODUCTION

The detection of cytomegalovirus (CMV) in the setting of inflammatory bowel disease often creates confusion whether CMV is a 'bystander' or 'disease.'

AREAS COVERED

This review discusses the clinical conundrum of CMV in ulcerative colitis, approach to discriminate infection from disease, and therapeutic considerations (immunosuppressive and anti-CMV treatment). CMV disease should be considered in corticosteroid refractory- dependent and thiopurine refractory disease. Endoscopy may reveal deep punched out ulcers, irregular ulcers, or cobble-stoning. The diagnosis rests on the presence and abundance of viral inclusion bodies on hematoxylin and eosin stain, positive immunohistochemistry, and/or positive tissue polymerase chain reaction. CMV disease is associated with worse outcomes including increased colectomy rates.

EXPERT OPINION

The timing and duration of antiviral drugs in CMV disease is debatable but depends on the load of CMV in tissue. In high-grade infection, CMV needs to be treated while increasing immunosuppression may work in the setting of low-grade infection. Ganciclovir is the drug of choice for treatment of CMV disease. Tumor necrosis factor inhibitors may be useful for treating underlying disease activity in the setting of CMV. Other emerging therapies include fecal microbiota transplantation. Randomized studies are necessary to define the best timing and duration of anti-CMV therapy.

Cytomegalovirus in pediatric inflammatory bowel disease patients with acute severe colitis

BACKGROUND

The prevalence and significance of cytomegalovirus (CMV) colitis in pediatric acute severe colitis is unknown. The aim of this study was to determine the prevalence of CMV in colonic mucosa of children with acute severe refractory colitis and compare the clinical characteristics and outcomes of CMV positive and negative patients.

METHODS

In a case-control study, colonic biopsy specimens from children with severe refractory colitis were tested for CMV, and matched with non-refractory IBD controls. We characterized CMV positive patients by assessing laboratory values, concurrent medications, and need for surgery as compared with CMV negative refractory colitis patients.

RESULTS

Colonic biopsies from 96 patients were evaluated for CMV; 48 with severe refractory colitis, and 48 non-refractory controls. There was an increased prevalence of CMV in severe refractory colitis [7/48 (14.6%), P < 0.0001]; all were previously CMV negative. Viral DNA burden on immunohistochemistry was not predictive of response to antiviral therapy or need for surgery at 12 months. Lymphopenia was seen in all CMV positive patients, but this did not demonstrate statistical significance (P = 0.09). We did not see an association between azathioprine or infliximab use and the need for surgery at 12 months.

CONCLUSIONS

There is an increased prevalence of CMV in colonic biopsies of pediatric patients with severe refractory colitis. Viral burden does not predict clinical outcomes or subsequent need for colectomy.

Impact of Epstein-Barr virus infection on inflammatory bowel disease (IBD) clinical outcomes

OBJECTIVE

To evaluate the role of Epstein-Barr virus (EBV) on the intestinal mucosa in the evolution of inflammatory bowel disease (IBD), to investigate the risk factors for EBV infection and the frequency of EBV-associated lymphoproliferative disorders in IBD patients.

METHODS

Intestinal biopsies of IBD patients with available EBV status determined by Epstein-Barr-encoding RNA (EBER) in situ hybridization were searched in the Pathology Database of our center. Clinical information, including phenotypic characteristics of IBD, previous treatments, diagnosis of lymphoma, and patient outcome, were reviewed for all cases.

RESULTS

56 patients with IBD (28 Crohn´s disease, 27 ulcerative colitis and one unclassified colitis) were included. EBV in intestinal mucosa was positive in 26 patients (46%), in one case associated to a lymphoproliferative syndrome. EBV positivity was associated with severe histological activity (52% vs. 17.2%; p 0.007), presence of a lymphoplasmacytic infiltrate (50% vs. 33.3%; p 0.03) and active steroid treatment (61.5% vs. 33.3%; p 0.03). Multivariate analyses only found association between EBV and lymphoplasmacytosis (p 0.001). Escalation in previous treatment was significantly more frequent in the EBER+ group (53.8% vs. 26.7%; p 0.038). No cases developed lymphoma in the follow-up.

CONCLUSIONS

EBV on the intestinal mucosa is associated with a poor outcome of IBD and the need for escalation in therapy. Lymphoplasmacytic infiltrate is associated with EBV infection. EBER+ patients used steroids more frequently compared with EBER- patients. No EBER+ patients developed a lymphoma during follow-up.

Molecular Characterization and Seroprevalence of Hepatitis E Virus in Inflammatory Bowel Disease Patients and Solid Organ Transplant Recipients

Seroprevalence rates and molecular characterization of hepatitis E virus (HEV) prevalent in the Lithuanian human population has not yet been evaluated. Immunosuppressed individuals have been recognized as a risk group for chronic hepatitis due to HEV genotype 3 (HEV-3) infections. The objectives of the present study were to determine prevalence rates of anti-HEV antibodies among inflammatory bowel disease (IBD) patients and solid organ transplant (SOT) recipients, to isolate and characterize HEV strain present in the Lithuanian human population, and to investigate its capacity to infect non-human primate (MARC-145 and Vero), swine (PK-15) and murine (Neuro-2a) cells in vitro. In the present study, the significant difference of anti-HEV IgG prevalence between healthy (3.0% (95% CI 0–6.3)) and immunosuppressed individuals (12.0% [95% CI 8.1–15.9]) was described. Moreover, our findings showed that anti-HEV IgG seropositivity can be significantly predicted by increasing age (OR = 1.032, p < 0.01), diagnosis of IBD (OR = 4.541, p < 0.01) and reception of SOT (OR = 4.042, <0.05). Locally isolated HEV strain clustered within genotype 3i subtype of genotype 3 and was capable of infecting MARC-145 cells. This study demonstrates higher HEV seroprevalence in the risk group compared to healthy control individuals without confidence interval overlap. The high level of genetic homology between human and animal strains in Lithuania and the capacity of locally isolated strains to infect cells of non-human origin suggests its potential for zoonotic transmission.

Human Cytomegalovirus and Epstein-Barr virus specific immunity in patients with ulcerative colitis

Human Cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) are endowed with the ability of establishing lifelong latency in human hosts and reactivating in immunocompromised subjects, including patients suffering from ulcerative colitis (UC). We, therefore, aimed to investigate virus-specific immunity in UC patients. A cohort of 24 UC patients (14 responders and 10 refractory to therapy) and 26 control subjects was prospectively enrolled to undergo virus-specific serology (by ELISA assay) and assessment of both CD4⁺ and CD8⁺ virus-specific T-cell response (by interferon-γ enzyme-linked immunospotanalysis). In parallel, mucosal viral load was determined by quantitative real-time PCR and the values were correlated with both clinical and endoscopic indexes of activity. For statistics, the t-test, Mann-Withney test, Fisher's exact test and Spearman rank correlation test were applied; p < 0.05 was considered significant. EBV-specific CD4⁺ and CD8⁺ T-cell responses were significantly lower in UC patients compared to controls (p < 0.0001 and p = 0.0006, respectively), whereas no difference was found for HCMV-specific T-cell response. When dividing the UC group according to response to therapy, both responders and refractory UC patients showed a deficient EBV-specific CD4⁺ T-cell response with respect to controls (p < 0.04 and p = 0.0003, respectively). Moreover, both EBV and HCMV mucosal loads were significantly higher in refractory UC than in responders and controls (p = 0.007 and 0.003; and p = 0.02 and 0.001, respectively), and correlated with activity indexes. Steroid therapy seemed the main risk factor for triggering EBV colitis. Finally, no cases of IgM positivity were found in the study population. An impaired EBV-specific immunity was clearly evident in UC patients, mostly in those refractory to therapy. The ELISPOT assay may serve as new tool for quantifying and monitoring virus-specific T-cell immunity in UC.

Human Cytomegalovirus and Autoimmune Diseases: Where Are We?

Human cytomegalovirus (HCMV) is a ubiquitous double-stranded DNA virus belonging to the β-subgroup of the herpesvirus family. After the initial infection, the virus establishes latency in poorly differentiated myeloid precursors from where it can reactivate at later times to cause recurrences. In immunocompetent subjects, primary HCMV infection is usually asymptomatic, while in immunocompromised patients, HCMV infection can lead to severe, life-threatening diseases, whose clinical severity parallels the degree of immunosuppression. The existence of a strict interplay between HCMV and the immune system has led many to hypothesize that HCMV could also be involved in autoimmune diseases (ADs). Indeed, signs of active viral infection were later found in a variety of different ADs, such as rheumatological, neurological, enteric disorders, and metabolic diseases. In addition, HCMV infection has been frequently linked to increased production of autoantibodies, which play a driving role in AD progression, as observed in systemic lupus erythematosus (SLE) patients. Documented mechanisms of HCMV-associated autoimmunity include molecular mimicry, inflammation, and nonspecific B-cell activation. In this review, we summarize the available literature on the various ADs arising from or exacerbating upon HCMV infection, focusing on the potential role of HCMV-mediated immune activation at disease onset.

Substantial Epstein-Barr virus reactivation in a case of severe refractory ulcerative colitis: a possible role in exacerbation

Ulcerative colitis (UC) is an inflammatory bowel disease that causes chronic inflammation in the colon. 5-aminosalicylic acid and immunosuppressive medications such as corticosteroids, immunomodulators, and biologic agents are used to treat these patients. However, patients with UC who receive immunosuppressive medications may be at risk for certain opportunistic infections. Epstein-Barr virus (EBV) is one of those opportunistic infections, and its pathogenic role has been implicated in refractory UC, but its pathogenicity should be further investigated. Here, we report a surgical case of refractory UC that demonstrated a serologically post-infected pattern of EBV at admission but that later had a high load of EBV in both the peripheral blood and colonic mucosa. These findings suggest that EBV may have been reactivated in the colon, after which it damaged the colonic mucosa and aggravated inflammation in this patient with UC. Thus, EBV might lead to severity and a refractory response against corticosteroids and anti-TNFα agents, necessitating emergency surgery. Viral surveillance for EBV in patients with refractory UC may facilitate understanding of the patient's pathophysiology and predicting response to medications, and the development of antiviral intervention for those patients may improve their prognosis.

Clinical features of Epstein-Barr virus in the intestinal mucosa and blood of patients with inflammatory bowel disease

BACKGROUND

The role of Epstein-Barr virus (EBV) in inflammatory bowel disease (IBD) remains to be elucidated. The aim of this study was to investigate the presence of EBV in the blood and intestinal mucosa of patients with IBD and evaluate the association between EBV positivity and IBD.

METHODS

Patients with IBD, hospitalized between January 2015 and April 2018, were enrolled. The EBV-DNA load in blood samples from each subject was analyzed by quantitative real-time polymerase chain reaction. EBV-encoded small-RNA 1 (EBER-1) was detected by in-situ hybridization in intestinal mucosa tissue sections of patients with IBD.

RESULT

EBV-DNA was detected in 48 out of 568 patients with IBD (8.4%), and EBER-1 positivity was detected in 27 of these patients (56.3%). Refractory IBD and severe mucosal inflammation were more common in patients with detectable levels of EBER-1 than in those without; the number of EBER-1-positive cells positively correlated with mucosal inflammation (P value < 0.05). Age (≥60 years old) and use of azathioprine were risk factors for EBV infection. There was no significant difference in clinical remission rate and surgical rate between the EBER-1 positive group and EBER-1 negative group, antiviral group and the non-antiviral group, among IBD patients who tested positive for EBV-DNA.

CONCLUSION

Elderly patients with IBD, treated with azathioprine, are more susceptible to EBV positivity. Further, EBV mucosal detection correlated with the severity of mucosal damage and refractoriness, but not prognosis.

Ulcerative Colitis and Cytomegalovirus Infection: From A to Z

Despite multiple studies, the role of cytomegalovirus [CMV] infection in exacerbating the severity of inflammation in ulcerative colitis [UC], and its response to treatment, remain debatable. Additionally, the optimal diagnostic tests for CMV infection in the setting of UC relapse, and timing of antiviral treatment initiation, remain unclear. The challenge faced by gastroenterologists is to differentiate between an acute UC flare and true CMV colitis. It seems that the presence of CMV colitis, as defined by the presence of intranuclear or intracellular inclusion bodies on haematoxylin and eosin [H&E] staining and/or positive immunohistochemistry [IHC] assay on histology, is associated with more severe colitis. Patients with CMV infection and acute severe colitis are more resistant to treatment with corticosteroids than non-infected patients. This refractoriness to steroids is related to colonic tissue CMV viral load and number of inclusion bodies [high-grade CMV infection] which may have a pronounced effect on clinical outcomes and colectomy rates. Whereas many studies showed no effect for antiviral treatment on colectomy rates in CMV-infected UC patients, there was a significant difference in colectomy rates of patients with high-grade infection who received anti-viral therapy compared with those who did not receive treatment. It was therefore proposed that high-grade CMV disease indicates that the virus is acting as a pathogen, whereas in those with low-grade CMV disease, the severity of IBD itself is more likely to influence outcome. The different algorithms that have been put forward for the management of patients with UC and concomitant CMV infection are discussed.

Epstein-Barr virus infection in ulcerative colitis: a clinicopathologic study from a Chinese area

BACKGROUND

Opportunistic Epstein-Barr virus (EBV) infection in patients with ulcerative colitis (UC) has attracted increasing attention. This study aimed to evaluate the clinicopathological characteristics and clinical outcomes of UC with intestinal EBV infection and to explore the predictive value of blood EBV DNA for the presence of EBV in the intestine.

METHODS

Both peripheral blood and intestinal biopsies from 92 consecutive UC inpatients were included in this study. Normal colonic mucosal tissues from 20 colon cancer patients were used as controls. EBV testing and assessment were performed by EBV-DNA polymerase chain reaction (PCR), EBV-encoded small RNA in situ hybridization (EBER-ISH) and immunohistochemistry.

RESULTS

A total of 36 patients (39.1%) had UC with superimposed EBV colitis [EBER greater than 2/high-power field (HPF)]. EBER counts and disease activity were significantly correlated (p < 0.05). The major endoscopic findings revealed more irregular and longitudinal ulcers in patients with superimposed EBV colitis (p = 0.016, p = 0.021, respectively). Age, steroid dependence, and irregular ulcerations were identified as possible risk factors. The best EBER cut-off point for outcome prediction was 2.5/HPF. At a cut-off value of 2035 copies/ml, the sensitivity and specificity of the blood EBV-DNA PCR analysis for predicting EBV presence in the intestine were 76.5% and 68.5%, respectively. EBV-infected cells in UC with high EBV concentrations mainly included B lymphocytes by clinicopathology, and the infection might have progressed from the latent to the lytic phase of the EBV life cycle.

CONCLUSION

The EBER count is positively correlated with disease activity. The best cut-off point for outcome prediction is 2.5/HPF. A high EBV viremia load may effectively predict EBV presence in the colonic mucosa.

Chronic active Epstein-Barr virus infection involving gastrointestinal tract mimicking inflammatory bowel disease

Background

Chronic active Epstein-Barr virus infection (CAEBV) is a rare disease, which is difficult to be differentiated from inflammatory bowel disease (IBD). To cause the attention, we present twelve cases of CAEBV in immunocompetent patients with gastrointestinal tract involvement.

Methods

Twelve patients who fulfilled the diagnostic criteria of CAEBV were enrolled in this retrospective study. The control group was consisted of twenty-four IBD patients with EBV-DNA value increased in peripheral blood. The clinicopathologic and endoscopic characteristics were reviewed and analyzed.

Results

The major clinical presentations of CAEBV patients were intermittent fever (100%), hepatomegaly/splenomegaly (58%), lymphadenopathy (50%), diarrhea (50%) and hematochezia (50%). Compared with IBD patients, the incidence of intermittent fever and increased level of ferritin were significantly higher among CAEBV patients. The median values for EBV detected in peripheral blood were significantly higher in CAEBV group (1.42*10^6 copies/μg) than in IBD group (3.2*10^3 copies/μg, p<0.05). The main endoscopic findings of CAEBV included multifocal or isolated, irregular, multiform ulcers and diffuse inflammation, lacking of typical cobblestone appearance. Ten patients died within 5 years of disease onset. The average survival time is 21 months.

Conclusions

Symptoms such as intermittent fever, increased level of ferritin and atypical endoscopic findings could be a sign for CAEBV. Early detections of EBV-DNA in serum and EBV-encoded small nuclear RNA (EBER) by in situ hybridization in intestinal tissue are essential for differential diagnosis between CAEBV and IBD.

Cytomegalovirus and Inflammatory Bowel Diseases (IBD) with a Special Focus on the Link with Ulcerative Colitis (UC)

Cytomegalovirus (CMV) infects approximately 40% of adults in France and persists lifelong as a latent agent in different organs, including gut. A close relationship is observed between inflammation that favors viral expression and viral replication that exacerbates inflammation. In this context, CMV colitis may impact the prognosis of patients suffering from inflammatory bowel diseases (IBDs), and notably those with ulcerative colitis (UC). In UC, the mucosal inflammation and T helper cell (T_H) 2 cytokines, together with immunomodulatory drugs used for controlling flare-ups, favor viral reactivation within the gut, which, in turn, increases mucosal inflammation, impairs corticoid and immunosuppressor efficacy (the probability of steroid resistance is multiplied by more than 20 in the case of CMV colitis), and enhances the risk for colectomy. This review emphasizes the virological tools that are recommended for exploring CMV colitis during inflammatory bowel diseases (IBD) and underlines the interest of using ganciclovir for treating flare-ups associated to CMV colitis in UC patients.

Current Diagnostic and Therapeutic Approaches to Cytomegalovirus Infections in Ulcerative Colitis Patients Based on Clinical and Basic Research Data

Human cytomegalovirus (HCMV) is a ubiquitous herpesvirus (the human herpesvirus 5) and an opportunistic pathogen that primarily infects HIV-positive and other immuno-compromised patients. Retrospective studies in the field of inflammatory bowel disease (IBD) have suggested a relationship between a concomitant colonic HCMV infection and poor outcomes in patients with an ulcerative colitis (UC) due to the presence of HCMV in surgical specimens of patients with a toxic megacolon or a steroid-resistant UC. Therefore, gastroenterologists have focused on the contribution of HCMV infections in the exacerbation of UC. Numerous studies have addressed the benefits of treating colonic HCMV reactivation in UC using an antiviral treatment. However, its clinical relevance remains uncertain as only a few prospective studies have assessed the direct relationship between clinical outcomes and the viral load of HCMV in colonic tissues. HCMV reactivation can be triggered by inflammation according to fundamental research studies. Thus, optimal control of intestinal inflammation is essential for preventing an HCMV reactivation in the intestinal mucosa. Indeed, several reports have indicated the effectiveness of an anti-tumor necrosis factor-alpha (TNFα) treatment in patients with an active UC and concomitant HCMV infections. In this review, we describe the mechanism of HCMV reactivation in UC cases and discuss the current issues regarding diagnosis and treatment of HCMV infections in UC patients.

Infection of Epstein-Barr Virus is Associated with the Decrease of Helios+FoxP3+Regulatory T Cells in Active Ulcerative Colitis Patients

Background: Loss of immune homeostasis to enteric pathogens is considered to be involved in the pathogenesis of ulcerative colitis (UC), and regulatory T cells (Tregs) are key for this immune homeostasis. Helios exhibits an important effect on regulating the suppressive function of Tregs. Epstein-Barr virus (EBV) is more commonly detected in UC. However, whether there is an association between EBV infection and Helios⁺Tregs and its impact on disease activity of UC remain unclear. We aimed to explore the clinical significance of Helios⁺Tregs and their potential association with EBV infection in UC. Methods: Seventy-six UC patients and 38 controls were consecutively enrolled. Helios⁺FoxP3⁺Tregs were analyzed using flow cytometry and compared among groups. Eight active UC patients treated with 5-aminosalicylic acid were followed up. Correlation analyses were conducted between Helios⁺FoxP3⁺Tregs and disease activity indicators. In addition, EBV viral loads in the mucosal lesion were quantified in active UC by quantitative polymerase chain reaction and were comprehensively analyzed in subgroups of different disease severity, and their associations with Helios⁺FoxP3⁺Tregs were also analyzed. Results: Helios⁺FoxP3⁺Tregs were significantly decreased in active UC and were inversely correlated with serum C-reactive protein and Mayo score. Moreover, we observed the recovery of Helios⁺FoxP3⁺Tregs in followed-up active UC achieving remission after treatment. EBV loads were higher in active UC, and levels of Helios⁺FoxP3⁺Tregs in the EBV-positive subgroup were lower than the EBV-negative subgroup in moderate and severe active patients. Most importantly, we found that Helios⁺FoxP3⁺Tregs were significantly negatively correlated with EBV viral loads. Conclusion: Helios⁺FoxP3⁺Tregs are likely to play a pivotal role in disease activity of UC and may be influenced by EBV infection.

HCMV-encoded US7 and US8 act as antagonists of innate immunity by distinctively targeting TLR-signaling pathways

The mechanisms by which many human cytomegalovirus (HCMV)-encoded proteins help the virus to evade immune surveillance remain poorly understood. In particular, it is unknown whether HCMV proteins arrest Toll-like receptor (TLR) signaling pathways required for antiviral defense. Here, we report that US7 and US8 as key suppressors that bind both TLR3 and TLR4, facilitating their destabilization by distinct mechanisms. US7 exploits the ER-associated degradation components Derlin-1 and Sec61, promoting ubiquitination of TLR3 and TLR4. US8 not only disrupts the TLR3-UNC93B1 association but also targets TLR4 to the lysosome, resulting in rapid degradation of the TLR. Accordingly, a mutant HCMV lacking the US7-US16 region has an impaired ability to hinder TLR3 and TLR4 activation, and the impairment is reversed by the introduction of US7 or US8. Our findings reveal an inhibitory effect of HCMV on TLR signaling, which contributes to persistent avoidance of the host antiviral response to achieve viral latency.

Human cytomegalovirus (HCMV) has evolved several mechanisms to evade the host immune response. Here, Park et al. show that HCMV-encoded US7 and US8 proteins bind TLR3 and TLR4 and facilitate TLR degradation by distinct mechanisms, including ER-associated and lysosomal degradation.

A review on co-existent Epstein-Barr virus-induced complications in inflammatory bowel disease

There have been growing reports regarding the presence of Epstein-Barr virus (EBV) in the intestine portions of patients suffering from ulcerative colitis and Crohn's disease, collectively termed as inflammatory bowel disease (IBD). Indeed, the prevalence of EBV infection increases in IBD patients due to prolonged employment of immunosuppressive drugs including azathioprine and infliximab. In turn, coinfection with EBV increases the propensity of development of lymphoproliferative disorders in the gastrointestinal tract including Hodgkin lymphoma, non-Hodgkin lymphomas, and lymphoepithelioma-like cholangiocarcinoma. Therefore, it is recommended that IBD patients on prolonged immunomodulator therapy should be monitored for the presence of primary intestinal lymphoproliferative diseases. Moreover, coinfection of EBV complicates the clinical course of IBD by increasing the severity, chronicity, inducing refractoriness and increasing relapse incidences. Therefore, it is recommended that antiviral drugs should be added in the conventional IBD therapy in the suspected cases of EBV infection. Research has also revealed that EBV-induced colitis is very similar to IBD and there are chances of misdiagnosis of IBD in the presence of EBV colitis. The proper diagnosis of EBV infection along with its timely treatment is necessary to avoid the severe complications in patients of IBD. The present review discusses the role of EBV coinfection in increasing the clinical complications of IBD patients.

SDF-1/CXCR4 axis enhances the immunomodulation of human endometrial regenerative cells in alleviating experimental colitis

Endometrial regenerative cells (ERCs) are a new type of mesenchymal-like stromal cells, and their therapeutic potential has been tested in a variety of disease models. SDF-1/CXCR4 axis plays a chemotaxis role in stem/stromal cell migration. The aim of the present study was to investigate the role of SDF-1/CXCR4 axis in the immunomodulation of ERCs on the experimental colitis. The immunomodulation of ERCs in the presence or absence of pretreatment of SDF-1 or AMD3100 was examined in both in vitro cell culture system and dextran sulphate sodium-induced colitis in mice. The results showed that SDF-1 increased the expression of CXCR4 on the surface of ERCs. As compared with normal ERCs, the SDF-1-treated, CXCR4 high-expressing ERCs more significantly suppressed dendritic cell population as well as stimulated both type 2 macrophages and regulatory T cells in vitro and in vivo. Meanwhile, SDF-1-pretreated ERCs increased the generation of anti-inflammatory factors (e.g., IL-4, IL-10) and decreased the pro-inflammatory factors (e.g., IL-6, TNF-α). In addition, SDF-1-pretreated CM-Dil-labeled ERCs were found to engraft to injured colon. Our results may suggest that an SDF-1-induced high level of CXCR4 expression enhances the immunomodulation of ERCs in alleviating experimental colitis in mice.

Escherichia coli Pathobionts Associated with Inflammatory Bowel Disease

Gut bacteria play a key role in initiating and maintaining the inflammatory process in the gut tissues of inflammatory bowel disease (IBD) patients, by supplying antigens or other stimulatory factors that trigger immune cell activation. Changes in the composition of the intestinal microbiota in IBD patients compared to that in healthy controls and a reduced diversity of intestinal microbial species are linked to the pathogenesis of IBD. Adherent invasive Escherichia coli (AIEC) has been linked to Crohn's disease (CD) patients, while diffusely adherent E. coli (DAEC) has been associated with ulcerative colitis (UC). Bacteriological analysis of intestinal biopsy specimens and fecal samples from IBD patients shows an increased number of E. coli strains belonging to the B2 phylogenetic group, which are typically known as extraintestinal pathogenic E. coli (ExPEC). Results from studies of both cell cultures and animal models reveal pathogenic features of these E. coli pathobionts, which may link them to IBD pathogenesis. This suggests that IBD-associated E. coli strains play a facilitative role during IBD flares. In this review, we explain IBD-associated E. coli and its role in IBD pathogenesis.

Diagnosis and Management of CMV Colitis

PURPOSE OF REVIEW

Cytomegalovirus (CMV) colitis is a relatively common end-organ infectious complication in immunocompromised hosts which negatively affects clinical outcomes. This paper presents the contemporary approaches to the diagnosis and management of CMV colitis and discusses some of the controversies of this condition, focusing on methods of diagnosis.

RECENT FINDINGS

While certain risk factors for CMV colitis are well recognized, the clinical as well as endoscopic features of this condition are nonspecific. Rapid diagnosis and management are usually needed, especially in critically ill patients, which necessitate invasive diagnostic procedures. Hematoxylin and eosin staining of colonic mucosal tissue may show the typical viral inclusions associated with CMV colitis that are highly specific for this condition. However, the staining has low sensitivity compared to immunohistochemistry, which is considered the gold standard for diagnosis of CMV colitis. Tissue polymerase chain reaction (PCR) is highly sensitive for diagnosis, but is controversial for many reasons, detailed in this paper. A high index of suspicion is needed, and once diagnosis is made, treatment should be highly considered to improve the outcome of these severely ill patients. Noninvasive diagnostic tests will be available in the future and will hopefully improve the diagnosis and care of patients with CMV colitis.

Accuracy of diagnostic tests and a new algorithm for diagnosing cytomegalovirus colitis in inflammatory bowel diseases: a diagnostic study

PURPOSE

The optimal method for detecting CMV colitis in patients with inflammatory bowel disease (IBD) has not been established. We wanted to investigate which diagnostic test would be most accurate when defining CMV colitis rather by the further clinical course than by using another diagnostic modality.

METHODS

All consecutive patients with moderately or severely active IBD who had been tested for CMV by PCR, histology, or antigenemia assay at the two campuses CBF and CCM of the Charité - Universitätsmedizin Berlin between September 2006 and September 2009 were included in this retrospective study. During that time, in patients with a positive CMV test, immunosuppressive treatment of any kind was immediately reduced and antiviral treatment was started. This allowed identifying patients who responded to antiviral treatment and those who only responded to later escalation of immunosuppressive therapy.

RESULTS

One hundred and nine patients were identified, out of whom nine were considered to have clinically relevant CMV colitis. Sensitivity and specificity were 1 and 0.94 for CMV PCR and 0.5 and 1 for pp65 antigen immunofluorescence assay from peripheral blood, 0.67 and 0.98 for immunohistochemistry, and 0.17 and 0.98 for hematoxylin-eosin staining. When using absence of leukocytosis, splenomegaly, and steroid refractory disease as clinical parameters to test for CMV colitis, blood CMV PCR and immunohistochemistry were able to exclude CMV colitis in negative patients with a 75% likelihood of positive patients to have clinically relevant CMV colitis.

CONCLUSIONS

Blood-based CMV PCR together with simple clinical parameters can exclude clinically relevant CMV colitis at a high specificity.

Cytomegalovirus colitis in inflammatory bowel disease and after haematopoietic stem cell transplantation: diagnostic accuracy, predictors, risk factors and disease outcome

BACKGROUND

Concurrent cytomegalovirus (CMV) colitis in inflammatory bowel disease (IBD) and after haematopoietic stem cell transplantation (HSCT) is an important clinical entity associated with high rates of morbidity and mortality.

METHODS

A retrospective study of 47 patients with IBD and 61 HSCT patients was performed regarding the evaluation of diagnostic accuracy of applied methods, predictors, risk factors for CMV disease manifestation, the proportion of patients with antiviral treatment and disease outcome.

RESULTS

The sensitivity of quantitative PCR (qPCR) with a cut-off value of >250 copies/mg for CMV colitis in patients with IBD and HSCT patients was 79% and 92%, respectively. Predictors for CMV colitis in the IBD cohort were anaemia and the presence of endoscopic ulcers. Glucocorticoids, calcineurin inhibitors and >2 concurrent lines of treatment with immunosuppressive drugs could be identified as risk factors for CMV colitis in the IBD cohort with an OR of 7.1 (95% CI 1.7 to 29.9), 21.3 (95% CI 2.4 to 188.7) and 13.4 (95% CI 3.2 to 56.1), respectively. Predictors and risk factors for CMV gastroenteritis in the HSCT cohort was the presence of endoscopic ulcers (OR 18.6, 95% CI 3.3 to 103.7) and >2 concurrent lines of treatment with immunosuppressive drugs. Antiviral therapy was administered in 70% of patients with IBD and 77% of HSCT patients with CMV disease. 71% of antiviral-treated patients with IBD showed an improvement of their disease activity and 14% underwent colectomy. The mortality rate of HSCT patients was 21% irrespective of their CMV status.

CONCLUSIONS

In addition to the implementation of histological methods, qPCR may be performed in patients with suspected high-risk IBD and HSCT patients for CMV colitis. Independent validations of these results in further prospective studies are needed.

Mouse Gamma Herpesvirus MHV-68 Induces Severe Gastrointestinal (GI) Dilatation in Interferon Gamma Receptor-Deficient Mice (IFNγR-/-) That Is Blocked by Interleukin-10

Inflammatory bowel disease (IBD) and Clostridium difficile infection cause gastrointestinal (GI) distension and, in severe cases, toxic megacolon with risk of perforation and death. Herpesviruses have been linked to severe GI dilatation. MHV-68 is a model for human gamma herpesvirus infection inducing GI dilatation in interleukin-10 (IL-10)-deficient mice but is benign in wildtype mice. MHV-68 also causes lethal vasculitis and pulmonary hemorrhage in interferon gamma receptor-deficient (IFNγR-/-) mice, but GI dilatation has not been reported. In prior work the Myxomavirus-derived anti-inflammatory serpin, Serp-1, improved survival, reducing vasculitis and pulmonary hemorrhage in MHV-68-infected IFNγR-/- mice with significantly increased IL-10. IL-10 has been investigated as treatment for GI dilatation with variable efficacy. We report here that MHV-68 infection produces severe GI dilatation with inflammation and gut wall degradation in 28% of INFγR-/- mice. Macrophage invasion and smooth muscle degradation were accompanied by decreased concentrations of T helper (Th2), B, monocyte, and dendritic cells. Plasma and spleen IL-10 were significantly reduced in mice with GI dilatation, while interleukin-1 beta (IL-1β), IL-6, tumor necrosis factor alpha (TNFα) and INFγ increased. Treatment of gamma herpesvirus-infected mice with exogenous IL-10 prevents severe GI inflammation and dilatation, suggesting benefit for herpesvirus-induced dilatation.

Refractory inflammatory bowel disease: is there a role for Epstein-Barr virus? A case-controlled study using highly sensitive Epstein-Barr virus-encoded small RNA1 in situ hybridization

A potential role for viral infections has been implicated in inflammatory bowel disease (IBD) unresponsive to medical treatment. It is well known that Epstein-Barr virus (EBV) infection can elicit a brisk mononuclear response in the gastrointestinal tract. The aim of this study was to further evaluate the role of EBV in patients with refractory IBD and compare them with nonrefractory IBD cases. Surgically resected colonic specimens from 67 patients with refractory IBD (62 with ulcerative colitis, 3 patients with Crohn disease, and 2 patients with indeterminate colitis) were retrieved. Twelve colectomy specimens from patients with ulcerative colitis who had undergone resections for dysplasia or endometriosis were included as controls. Highly sensitive EBV-encoded small RNA1 (EBER-1) in situ hybridization was performed on a representative block from each specimen. EBER-1 reactivity was graded as absent, focal, or diffuse. EBV was detected in 60% (40/67) of patients with refractory IBD compared with 25% (3/12) of the control group (P < .05). Focal EBER-1 positivity was present in 45% of cases of refractory IBD compared with 25% of controls. Diffuse EBER-1 reactivity was seen in 15% of cases of refractory IBD (10/67); none of the samples from the control group contained diffuse EBER-1 positivity. There was a positive correlation between EBER positivity and depth of inflammation and mucosal ulceration in patients with refractory IBD. Our findings suggest a potential role for EBV infection in patients with refractory IBD.

Diagnosis of Cytomegalovirus Infection during Exacerbation of Ulcerative Colitis

BACKGROUND/AIMS

The role of cytomegalovirus (CMV) reactivation during exacerbations of ulcerative colitis (UC) is yet a matter of debate, and assessment of CMV infection in UC patients remains an ongoing challenge. We aimed to identify associated parameters and compare detection methods for CMV infection during UC exacerbation.

METHODS

Clinical, pathological and virological parameters were retrospectively analyzed in all patients hospitalized in our institution for UC exacerbation between January 2009 and April 2015, who underwent full evaluation for CMV infection in colonic tissue by histopathology, immunohistochemistry (IHC) and CMV-PCR.

RESULTS

Of 28 patients who underwent full examination for tissue CMV-infection, 13 (46.4%) were found to be positive for CMV. Tissue CMV-PCR was more sensitive for the detection of CMV infection than histopathology and IHC. CMV-positive patients had a statistically higher frequency of recent steroid treatment and fever, with higher mean partial Mayo scores and lower mean albumin levels. There were no significant differences between CMV-positive and CMV-negative patients in terms of age, severity of colitis and disease duration. In a multivariable model, only recent steroid treatment and fever were independently associated with colonic CMV infection.

CONCLUSIONS

This study provides a clinical model to detect the presence of CMV infection in patients hospitalized with UC exacerbation, which could direct proper investigation and facilitate timely empirical therapy.

Direct Detection of T- and B-Memory Lymphocytes by ImmunoSpot® Assays Reveals HCMV Exposure that Serum Antibodies Fail to Identify

It is essential to identify donors who have not been infected with human cytomegalovirus (HCMV) in order to avoid transmission of HCMV to recipients of blood transfusions or organ transplants. In the present study, we tested the reliability of seronegativity as an indicator for the lack of HCMV exposure in healthy human blood donors. Eighty-two HCMV seronegative individuals were identified, and their peripheral blood mononuclear cells (PBMC) were tested in ImmunoSpot® assays for the presence of HCMV-specific T- and B-memory lymphocytes. Eighty-two percent (67 of 82) of these HCMV seronegative individuals featured at least one memory cell that was lineage specific for HCMV, with the majority of these subjects possessing CD4+ and CD8+ T cells, as well as B cells, providing three independent lines of evidence for having developed immunity to HCMV. Only 15 of these 82 donors (18%) showed neither T- nor B-cell memory to HCMV, consistent with immunological naïveté to the virus. The data suggest that measurements of serum antibodies frequently fail to reveal HCMV exposure in humans, which may be better identified by direct detection of HCMV-specific memory lymphocytes.

CMV Infection in Pediatric IBD

PURPOSE OF REVIEW

Patients with inflammatory bowel disease (IBD) are predisposed to infections. Cytomegalovirus (CMV) colitis in adult IBD patients, particularly ulcerative colitis (UC), is related to severe or steroid-refractory disease. The aim of this review is to summarize the data on the prevalence and role of CMV colitis in children with IBD.

RECENT FINDINGS

Data on CMV colitis in children continue to be very limited due to its rarity. As in adults, children with coexisting UC and CMV tend to have more severe colitis, are resistant to corticosteroids, and are at high risk for colectomies on short- and long-term follow-up. In children, as in adults, the significance of CMV colitis, in terms of whether CMV is a pathogen that aggravates acute severe colitis or simply reflects disease severity, is still unknown.

Analysis of gastrointestinal virus infection in immunocompromised hosts by multiplex virus PCR assay

Regarding viral infection of intestinal mucosa, there have been only a few studies on limited diseases, targeting a few herpes family viruses. In this study, we analyzed 12 kinds of DNA viruses including 8 species of herpes family viruses in the gastrointestinal mucosa of patients with hematologic malignancies, inflammatory bowel diseases, collagen diseases, or other miscellaneous forms of gastroenteritis using the multiplex virus PCR assay, which we recently developed. The virus PCR assay yielded positive results in 63 of 102 patients; Epstein-Barr virus (EBV) was the most frequently detected, followed by cytomegalovirus (CMV), human herpes virus 6 (HHV-6), HHV-7, parvovirus B19, and herpes simplex virus type 1. The frequencies of viral detection in the 4 diseases were similar involving these 6 viruses. Regarding CMV colitis, the multiplex virus PCR assay was superior to the immunohistopathologic method in detecting CMV. All viruses were more efficiently detected in the mucosa than in the blood in individual patients. These results suggest that CMV, EBV, and HHV-6 were commonly detected in the gastrointestinal mucosa of patients with these 4 diseases, and our multiplex virus PCR assay was useful for the early diagnosis of gastrointestinal virus infection, especially CMV colitis.

Identification of clinically relevant cytomegalovirus infections in patients with inflammatory bowel disease

Several lines of evidence indicate that cytomegalovirus infection can be substantially associated with onset of inflammatory bowel disease, especially in patients refractory to immunosuppressive treatment. As cytomegalovirus is widely spread in the population, here we present a quantitative detection system suitable to differentiate clinically relevant cytomegalovirus infection from common latent cytomegalovirus. Using a quantitative real-time PCR approach, cytomegalovirus viral load was evaluated in 917 formalin-fixed and paraffin-embedded colon biopsy samples of 136 patients diagnosed with inflammatory bowel disease. Besides initial cytomegalovirus testing, the PCR system was also used to monitor therapy response after antiviral treatment. Cytomegalovirus DNA was detected in 37 patients (27%) with varying viral loads ranging from 5 to 8.7 × 10⁵ copies/10⁵ cells. Thereof, 13 patients (35%) received an antiviral treatment with 12 of them going into remission (92%). Later, five patients displayed a relapse and three patients who agreed to restart antiviral treatment again showed positive therapy response. A retrospective comparison of viral loads with antiviral therapy response revealed a threshold of 600 cytomegalovirus copies/10⁵ cells as indicative for clinically relevant infection. Of note, sensitivity of cytomegalovirus detection by immunohistochemistry was found to be insufficient to reliably identify antiviral therapy responders. In conclusion, quantitative real-time PCR using formalin-fixed biopsy samples is suitable for detection of cytomegalovirus infection in tissue samples of patients with inflammatory bowel disease. Moreover, it allows the definition of a viral load threshold, predictive for clinical relevance concerning antiviral therapy response.

Is cytomegalovirus infection related to inflammatory bowel disease, especially steroid-resistant inflammatory bowel disease? A meta-analysis

BACKGROUND

Human cytomegalovirus (HCMV) infection has been associated with inflammatory bowel disease (IBD). Numerous studies have been conducted to analyze the association between HCMV infection and risk of IBD and steroid-resistant IBD, but no clear consensus had been reached.

OBJECTIVES

The aim of this study was to confirm this relationship precisely by doing a systematic review and meta-analysis.

STUDY DESIGN

We identified relevant studies through a search of PubMed and Embase. Studies were eligible for inclusion if they 1) evaluated the association between HCMV infection and IBD disease; 2) evaluated the association between HCMV infection and steroid-resistant IBD disease; 3) were case-control studies or nested case-control studies; 4) provided the numbers (or percentage) of positivity for HCMV infection in cases and controls, respectively. Data were extracted and analyzed independently by two investigators.

RESULTS AND CONCLUSION

A total of 18 studies including 1,168 patients and 951 health groups was identified, and HCMV infection was distinctly confirmed as a risk factor for the occurrence and development of IBD. When involving 17 studies including 1,306 IBD patients, a total of 52.9% of patients in the cytomegalovirus (CMV)-positive groups were observed to have steroid resistance, compared with 30.2% of patients in the CMV-negative groups. There was a significant difference in the risk of steroid resistance between people exposed to HCMV infection and those not exposed HCMV infection in IBD patients. This meta-analysis suggested that HCMV infection is associated with an increased risk for IBD and steroid-resistant IBD.

Looking into Enteric Virome in Patients with IBD: Defining Guilty or Innocence?

BACKGROUND

Although there is some evidence suggesting that certain viruses may be involved in the onset of inflammatory bowel disease (IBD), data regarding viral prevalence and viral load in blood and mucosa of patients with IBD are scarce. The main aim of this study is to evaluate the prevalence and viral load of common Epstein-Barr virus (EBV), cytomegalovirus (CMV), and human herpes virus 6 in blood and mucosa of adult patients with endoscopic active IBD.

METHODS

From January to December 2014, ulcerative colitis and Crohn's disease patients with active endoscopic disease were consecutively enrolled. Subjects undergoing colonoscopy for colorectal cancer screening served as healthy controls (HCs). Paired blood and mucosal samples from each patient and HC were collected for EBV, CMV, and human herpes virus 6 quantitative real time polymerase chain reaction assessment of the viral load.

RESULTS

One hundred forty-five subjects were included; 95 IBD patients with active endoscopic disease (43 ulcerative colitis and 52 Crohn's disease) and 50 healthy subjects. CMV and EBV DNA were detected more frequently in the mucosa of patients with IBD compared with HCs (CMV P = 0.017; EBV P < 0.001), irrespective of IBD type. The frequency of human herpes virus 6 DNA detection both in the blood and in the mucosa did not differ between patients with IBD and HCs. EBV median viral load was similar in the inflamed and noninflamed mucosa was not affected by the use of immunomodulators and/or anti-tumor necrosis factor alpha agents, and did not correlate with endoscopic disease activity.

CONCLUSIONS

EBV, and to a lesser extent CMV, were more prevalent in patients with IBD than in HCs. Mucosal viral load was not influenced by the therapeutic regimen, did not differ between inflamed and noninflamed mucosa, and did not seem to be influenced by the endoscopic activity of the disease, suggesting that EBV may be more involved in the onset of IBD than in its severity and clinical evolution.

Approach to cytomegalovirus infections in patients with ulcerative colitis

Cytomegalovirus (CMV) reactivation is common in patients with severe ulcerative colitis (UC), and may ref lect exacerbation of mucosal inf lammation and/or administration of immunosuppressants. The question of whether CMV is an active pathogen or 'an innocent bystander' in the exacerbation of UC remains controversial. Patients with UC exacerbated by reactivated CMV experience worse prognoses than those without CMV reactivation and antiviral therapy significantly reduces the need for colectomy in patients with severe UC and high-grade CMV infection, indicating that CMV plays a role in UC prognosis. Therefore, the CMV status of patients on immunosuppressants, particularly those with steroid-refractory or -dependent UC, should be tested. When CMV is detected, be performed based on should adequate treatment the extent of the viral load and the presence of certain clinical features including a large ulcer. Anti-tumor necrosis factor agents may be useful for treating CMV colitis complicating UC.

Diagnostic Accuracy of Blood-Based Tests and Histopathology for Cytomegalovirus Reactivation in Inflammatory Bowel Disease: A Systematic Review and Meta-Analysis

BACKGROUND

It is unclear if traditional histopathology and noninvasive blood-based tests are sufficiently accurate to detect cytomegalovirus (CMV) reactivation in inflammatory bowel disease. Therefore, we assessed the diagnostic accuracy of these tests compared with immunohistochemistry (IHC) and tissue polymerase chain reaction (PCR).

METHODS

A systematic search of electronic databases was performed from inception through January 2016 for observational studies comparing diagnostic tests for CMV reactivation in inflammatory bowel disease. IHC and tissue PCR were considered reference standards and were used to evaluate the accuracy of blood-based tests and hematoxylin and eosin histopathology. Weighted summary estimates with 95% confidence intervals (CIs) were calculated using bivariate analysis.

RESULTS

Nine studies examined the accuracy of blood-based tests for predicting colonic CMV reactivation: 5 studies by pp65 antigenemia and 4 studies by blood PCR. The overall sensitivity was 50.8% (95% CI, 19.9-81.6), the specificity was 99.9% (95% CI, 99-100), and the positive predictive value was 83.8% (95% CI, 58.6-95.0). The sensitivities of pp65 and blood PCR were 39.7% (95% CI, 27.4-52.1) and 60.0% (95% CI, 46.5-73.5), respectively. Nine studies examined the sensitivity of histopathology. The overall sensitivity was 12.5% (95% CI, 3.6-21.4), 34.6% by IHC (95% CI, 13.8-55.4), and 4.7% by tissue PCR (95% CI, 1.2-17.1).

CONCLUSIONS

Although blood-based tests seem to predict colonic CMV reactivation, they are insensitive tests. Similarly, histopathology has poor sensitivity for detecting colonic CMV. In agreement with current guidelines, these tests should not replace IHC or tissue PCR for detecting CMV reactivation in inflammatory bowel disease.

PCR detection of human herpesviruses in colonic mucosa of individuals with inflammatory bowel disease: Comparison with individuals with immunocompetency and HIV infection

BACKGROUND

Detection of human herpesviruses (HHVs) other than cytomegalovirus (CMV) in colonic mucosa of individuals with inflammatory bowel disease (IBD) remains unknown. This study identified eight HHVs in the colonic mucosa of individuals with IBD and compared the results with immunocompetent and human immunodeficiency virus (HIV)-infected individuals.

METHODS

A total of 89 individuals who had colorectal ulcer on colonoscopy were enrolled: 26 with immunocompetency (n = 26), 41 with IBD, and 22 with HIV infection. We examined the colonic ulcers for the presence of eight HHVs-herpes simplex virus (HSV)-1/2, varicella zoster virus (VZV), CMV, Epstein-Barr virus (EBV), HHV-6, HHV-7, and HHV-8-using mucosal PCR.

RESULTS

The IBD group had positivity rates of 0%, 0%, 0%, 53.7%, 24.4%, 39%, 39%, and 0% for HSV-1, HSV-2, VZV, EBV, CMV, HHV-6, HHV-7, and HHV-8, respectively. The positivity rates of EBV and CMV in colonic mucosa increased significantly in the order of the immunocompetent, IBD, and HIV groups (EBV: 23.1%, 53.7%, 72.7%, P for trend = 0.0005; CMV, 7.7%, 24.4%, 54.5%, P for trend = 0.0003, respectively), but no increase was found in the other HHVs. Median mucosal EBV DNA values in the immunocompetent, IBD, and HIV groups were 0, 76, and 287 copies/μg DNA, respectively (P for trend = 0.002). Corresponding median mucosal CMV DNA values were 0, 0, and 17 copies/μg DNA (P for trend = 0.0001). There was no significant difference in the positivity rates of the eight HHVs between ulcerative colitis and Crohn's disease.

CONCLUSION

The HHVs of EBV, CMV, HHV-6, and HHV-7, but not of HSV-1, HSV-2, VZV, or HHV-8, were identified in the colonic mucosa of IBD individuals. EBV and CMV in colonic mucosa was correlated with host immune status in increasing order of immunocompetent, IBD, and HIV-infected individuals.

Differential cellular localization of Epstein-Barr virus and human cytomegalovirus in the colonic mucosa of patients with active or quiescent inflammatory bowel disease

The role of human cytomegalovirus (HCMV) and Epstein-Barr virus (EBV) in the exacerbation of inflammatory bowel disease (IBD) is still uncertain. We prospectively investigated the presence of EBV and HCMV infection in both epithelial and immune cells of colonic mucosa of IBD patients, both refractory and responders to standard therapies, in comparison with patients suffering from irritable bowel syndrome who were considered as controls, by using quantitative real-time polymerase chain reaction, immunohistochemistry and in situ hybridization, in an attempt to assess viral localization, DNA load, life cycle phase and possible correlation with disease activity indexes. We obtained clear evidence of the presence of high DNA loads of both viruses in either enterocytes or immune cells of refractory IBD patients, whereas we observed low levels in the responder group and an absence of detectable copies in all cell populations of controls. Remarkably, the values of EBV and HCMV DNA in inflamed mucosa were invariably higher than in non-inflamed areas in both IBD groups, and the EBV DNA loads in the cell populations of diseased mucosa of refractory IBD patients positively correlated with the severity of mucosal damage and clinical indexes of activity. Moreover, EBV infection resulted the most prevalent either alone or in combination with HCMV, while immunohistochemistry and in situ hybridization did not allow us to distinguish between the different phases of viral life cycle. Finally, as regards treatment, these novel findings could pave the way for the use of new antiviral molecules in the treatment of this condition.

Targeting cytomegalovirus during ulcerative colitis flare-ups

Human cytomegalovirus (CMV) is a common cause of opportunistic infection leading to severe and fatal disease in immune-compromised individuals. In inflammatory bowel disease patients, particularly those with ulcerative colitis (UC), CMV is often reactivated because these patients are frequently treated with immunosuppressive agents. Many reports have described the relationship between CMV reactivation and UC exacerbation, however, a therapeutic strategy for CMV infection in UC patients has not been established. Area covered: This review highlights therapeutic strategies for UC patients with CMV infection. Recent findings have suggested a benefit from antiviral therapy in patients with histologically proven CMV colitis and/or a high colonic CMV load as determined by quantitative PCR. Expert commentary: To decide who requires antiviral therapies and when we start antiviral therapies, prospective studies of large numbers of UC patients with CMV infection are needed. However, we should know that the bottom-line therapy for UC patients with CMV infection is to optimally control mucosal inflammation.

NASPGHAN Clinical Report: Surveillance, Diagnosis, and Prevention of Infectious Diseases in Pediatric Patients With Inflammatory Bowel Disease Receiving Tumor Necrosis Factor-α Inhibitors

Children and adolescents with inflammatory bowel disease (IBD) receiving therapy with tumor necrosis factor α inhibitors (anti-TNFα) pose a unique challenge to health care providers in regard to the associated risk of infection. Published experience in adult populations with distinct autoinflammatory and autoimmune diseases treated with anti-TNFα therapies demonstrates an increased risk of serious infections with intracellular bacteria, mycobacteria, fungi, and some viruses; however, there is a paucity of robust pediatric data. With a rising incidence of pediatric IBD and increasing use of biologic therapies, heightened knowledge and awareness of infections in this population is important for primary care pediatricians, pediatric gastroenterologists, and infectious disease (ID) physicians. This clinical report is the result of a consensus review performed by pediatric ID and gastroenterology physicians detailing relevant published literature regarding infections in pediatric patients with IBD receiving anti-TNFα therapies. The objective of this document is to provide comprehensive information for prevention, surveillance, and diagnosis of infections based on current knowledge, until additional pediatric data are available to inform evidence-based recommendations.

TRIM31 promotes Atg5/Atg7-independent autophagy in intestinal cells

Autophagy is responsible for the bulk degradation of cytosolic constituents and plays an essential role in the intestinal epithelium by controlling beneficial host-bacterial relationships. Atg5 and Atg7 are thought to be critical for autophagy. However, Atg5- or Atg7-deficient cells still form autophagosomes and autolysosomes, and are capable of removing proteins or bacteria. Here, we report that human TRIM31 (tripartite motif), an intestine-specific protein localized in mitochondria, is essential for promoting lipopolysaccharide-induced Atg5/Atg7-independent autophagy. TRIM31 directly interacts with phosphatidylethanolamine in a palmitoylation-dependent manner, leading to induction of autolysosome formation. Depletion of endogenous TRIM31 significantly increases the number of intestinal epithelial cells containing invasive bacteria. Crohn's disease patients display TRIM31 downregulation. Human cytomegalovirus-infected intestinal cells show a decrease in TRIM31 expression as well as a significant increase in bacterial load, reversible by the introduction of wild-type TRIM31. We provide insight into an alternative autophagy pathway that protects against intestinal pathogenic bacterial infection.